R- Theiltpí and RADIO REVIEW R

r- TheIlTPí AND RADIO REVIEW r

VOLUME XXIV

JANUARY 2nd -JUNE 26th, 1929

Published from the Offices of " THE WIRELESS WORLD " ILIFFE & SONS LTD., DORSET HOUSE, TUDOR ST., LONDON, E.C.4

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www.americanradiohistory.com 111111 i I I I iii 111111 11111 111111 III 111111 11111 I II I II I II I I III IIIIIIIIIIIIIIIIIIIIIIIIl1111111111111111111111illlllllllllllli' INDEX VOLUME XXIV JANUARY 2nd -JUNE 26th, 1929

(IIIIIIIIIII'IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII1IIillIIII-

Abets, Using the (Readers' Problems), 24 Cabinet Dimensions (Readers' Problems), 272 " Diode " Receiver, A Sensitive, 54 Abroad, Sets for, 473 - Effect of the, 213 Diode Rectifier, The (A Description of the "Kirkifier, ") Accumulator Charge, Duration of (Readers' Problems), " Cameo " Riverside Portable Case, 602 32 344 Canada's Quarter Million Licences, 211 Direction Finder, Portable, 614 Accumulators, Edwards Portable Set, 603 " Carco " Switches, 625 Directional Stations, Useful Aid for (Review), 516 " Topping " (Patent), 401 Carrier for Picture Receiver, 135 Distant Reception (Editorial), 215 -"Acoustics of Buildings" (Book Review) 623 Catalogues Disto 492 Received, 74, 334, 393, 411, 584, 599, 621, Fillers, A.C. High Frequency Valve, 883 648, 673 Distortion, Detecting (Readers' Problems), 84 "A.C.3," An Unstable (Readers' Problems), 112 Centralab Products, 135 of Piano Music (Readers' Problems), 473 -A Screen Grid (Readers' Problems), 237 Chakophone de Luxe Aerial Tuner, 393 -Double -Tuned Couplings (Readers' Problems), 83 A.C. Three, The Flat Dwellers', 450, 481. Charge Indicator, A, 522 Volume Control (Readers' Problems), 422 Three, The Flat Dwellers' (a Correction) 632 Changing Condensers (Readers' Problems), 498 -Dropping Volts, 213 - Valves, The New, 682 Dry Cell 48 Charging the Feed Condenser (Readers' Problems), 608 H.T. Batteries, -Adding a Tuned Aerial Circuit (Readers' Problems), 497 Charts, Useful 441, Dubilier H.F. Chokes, 77 Data, 43, 97, 120, 209, 316, 363, H.F. to the Pentode Two (Readers' Problems), 190 540, 668 " Toreador Screened Grid Four " (Kit Con- - H.F. Difficulties (Readers' Problems), 84 Choice of Valve Notes), 533 H.F. (Readers' Problems), 112 - structors' -Aerial Chaos in Paris, 390 Choke Coupling (Readers' Problems), 112 Dynamic Resistance, 274 Coupling, Continuously Variable (Readers' Pro- Filter, The, 54 - blems), 631 - Inductance, L.F. (Readers' Problems), 320 Loading, Reducing (Readers' Problems), 680 -Chokes, Iron Cored, carrying D.C. (useful data Charts), - Tuner, Chakophone de Luxe, " Earth," The Best, 320 393 668 - Tuning Unit, Tapped, East Coast, On the (Kit Constructors' Problems), 307 318 H.F. (Readers' Problems), 473 462 - Wire, Renewing (Readers' Problems), 287 Choosing Eastern Europe, Wireless in, - a Power Valve for the Reed Driven Loud Economy Measure, An (Readers' Aerials- for Broadcasting Stations (Editorial), 113 speaker, Problems), 111 298 Ediswan Pentodes (Valves We Have Tested), Indoor (Readers' Problems), 84 the Right Valve, 168 342 - Short (Readers' Problems), 24 Clear Valves Edwards Portable Set Accumulators, 603 - Glass (Patent), 401 Aermonic- Screen grid Valve Ekco H.T. Supply Unit, Model 3 F.12, 537 Holder, 602 Cleary Wet H.T. Batteries, 206 Election, U.S. Presidential, 36 Alarm, A Piezo -Flectric (Patent), 226 " Clix " Power Plug and Socket, 134 All Electric Amplifier, 634, 677 Clix Wood Electramonic D.C. H.T. Eliminator, 625 -screw and Parallel Pin Plugs, 353 Eliminators and Battery Chargers, 566 All -Wave Four, New (Readers' Problems), 448 Clubs, News from the, 20, 42, 130, 236, 253, 304, 467, -Electrical Reproduction of Sound (Editorial), 239 Altering an Elirnator, 344 536, 552 Electric Pick Problem " Always " Potential Divider, 513 Coil Connections 474 " -Up " (Patent), 652 (Readers' Problems), Supply Regulations, 53 Amateur Band Wavemeter, 493 Connections, Reversed (Readers' Problems), 631 -Electrostatic Loud Speaker, Vogt, 553 Status in Britain (Editorial), 633 -Coils and Screens (Readers' Problems), 272 -Amplification from Screen -Grid Valves, Eliminator, Altering an, 344 More, 458 for Europa III, 104 Design (Readers' Problems), 498 (See also under H.F. Amplification) -Colato Loud Speaker, 353 - D.C., 53 Amplifier, The, 234 Collett's " Eze -Way " Pulley, 207 - D.C. Junior (Readers' Problems), 632 L.F. Dessigning, 862 " Coltags," 603 - for Two -Valve Sets, An, 529 - (See also under H.F. Amplifier and L.F. Columbia H.T. Battery, Type No. 4,721, 460 - Output Voltage (Readers' Problems), 11.2 Ampl$rer) Colvergraph, The, 331 -Eliminator Voltage, Increasing, 213 Anode Bend Detection (Readers' Problems), 660 Combination Set (Readers' Problems), 111 Voltage Bend Detector, The Valve as an, 279, 326 Combining Measurement (Readers' Problems), 684 Output Choke and Output Transformer, 491 -Eloden Loud Speakers, 284 - Bend or Leaky Grid ? (Readers' Problems), Common 422 Batteries, 54 Empire Day, 1929 (Editorial), 523 - Current Variations (Readers' Problems), 394, 546 Composition of the Programmes (Editorial), 345 - Resistance and By-Pass Capacity (Readers' Condenser Receiver, New (Readers' Problems), 296 Plates, Mounting (Patent), 652 - Screened Four, Burndept (Broadcast Receivers), - Problems), 140 Condensers, Changing (Readers' Problems), 498 - 302 Aperiodic H.F. Amplification with Modern Valves, 173 Decoupling (Readers' Problems), 344 Erring Neighbour, An (Kit Constructors' Problems), Apparatus Reviewed, 410, 513, 585, 602, 624 - Testing (Readers' Problems), 370 222 Are Aerials Out of Date ? (Editorial), 573 -Cone Lóud Speaker, The, 208 Art et Technique Variable Condenser, 392 Continuously Variable Ether Congestion (Editorial), 142 Aerial Coupling (Readers' Eton " British Valves " (Valves We 75 Artificial Condenser (Readers' Problems), 447 Problems), 631 Have Tested), Avometer, 187 Control Primary H.T. Battery, 160 of Grid Voltage (Readers' Problems), 320 -Europa Portable, The, 500 Automatic Control (Readers' Problems), 189 Conversion, A Simple (Readers' Problems), 320 Coils for, 104 Auto -Fuse, Magnum, 625 " Corked " Aerials 473 III, (Readers' Problems), - III, Screen for, 104 Correspondence, 23, 50, 81, 110, 138, 164, 188, 212, -" Europa III," The (Readers' Problems), 24 235, 270, 294, 343, 366, 417, 444, 471, 496, 520, Batteries, Common, 54 European Broadcasting (Editorial), 609 569, 606, 629, 656 -Wave Bayliss Power Chokes, 624 Cossor L.F. Transformer, 672 " Everyman Four," Long (Readers' Problems) B.B.C. Policy (Editorial), 449 Melody Maker on 112 Ultra -Short Wavelengths (Kit Four " Reaction (Readers' Problems), 571 " Beamu " Pick -Up Carrier, 206 - Constructors' Notes), 221 ' - Four," Rebuilding the, 213 Berclif H.F. Choke, 393 Melody Maker, The New (Kit Constructors' - Four," Short-Wave, 632 Bias Battery Tricks (Readers' Problems), 369 - Notes), 92 -" Exact " Tuners, The, 105 Fallacy, A (Leaders' Problems), 238 Couplings H.F. Parallel Feed (Readers' Problems), 660 -Book Reviews, 264, 420, 616, 623, 637 Courting " Excess Stability " (Readers' Problems), 272 Failure (Readers' Problems), 631 Exide Unspillable 602 Books Received, 42, 76, 184, 420, 432, 671 Current Topics, 13, 41, 65, 94, 123, 159, 185, 197, 227, Accumulator, ` British General " Transformer, 207 258, Extending Wavelength Range (Readers' Problems), 285, 805, 329, 355, 379, 404, 436, 461, 421, 497 Industries Fair, Radio at the, 195, 223 487, 512, 535, 559, 578, 622, 645, 674 -Broadcast Brevities, 21, 51, 72, 109, 136, 205, 232, Cushions Extra L.F. Stage, An (Readers' Problems), 448 267, and Acoustics (Book Review), 623 " Eze -Way Collett's, 207 295, 312, 317, 368, 391, 415, 440, 468, 494, 617, Cutting Piezo Crystals (Patent), 558 " Pulley, 544, 567, 601, 626, 653, 676 Cylanite, 234 Licence Conditions, New (Editorial), 395 - Pictures, Receiving (Patent), 558 Fading, 54 - Receiver for the Deaf, 495 Danish Broadcasting, 643 False Assumption, A, 522 - Receivers, 70, 128, 302, 542, 568, 667 Deaf, Broadcast Constructors' Receiver for the, 495 Ferranti Screened Grid Three (Kit - Troubles in America (Editorial), 475 " Decoupling " a Portable (Readers' Problems), 884 Notes), 433 - Waveband, The (Readers' Problems), 474 Decoupling Condensers (Readers' Problems), 344 Valve Tester, 459 Broadcasting Relations Overseas (Editorial), 321 Resistances (Readers' Problems), 608 Fictitious Fault, A (Readers' Problems), 394 Stations, Aerials for (Editorial), 113 - Where it Scores, 53 Filament Voltage, Reducing (Readers' Problems), 447 Buenos Aires, Nauen to (A New Telephone Service), 73 -D.E.L. 610 and H.L. 610 (Valves We Have Tested), 19 Filter Unit, " Wearite," 319 Building a Picture Receiver, 2, 26 Demonstration Receiver, The Schools', 372, 427 Fire -Screen Loud Speaker Baffie, 439 Bu/gin H.F. Choke, 284 Detecting Distortion (Readers' Problems), 84 Flat- Dwellers' A.C. Three on an Open Aerial (Readers' Quick -Break Switch, 411 Detector Efficiency (Editorial), 523 Problems), 545 -Burndept Cabinet Cone Loud Speaker, Model 16'76, ; Efficiency, Improving, 524 " Flat -Dwellers' " A.C. Three, The, 450, 481 Correc- 565 -Detex R.C.C. Unit, 186 tion, 632 Empire Screened Four (Broadcast Receivers), 302 Diamond Accumulators, 565 Flat Tuning Wanted (Readers' Problems), 546 - Screened Portable, 682 Differential (Kit Reaction Control (Readers' Problems), 572 Follow the Specification Constructors' Problems), - Turntable, 603 Difficult Conditions (Readers' Problems), 238 642 -Buyers' Guide to Portable Sets, 1929, 585 Difficulties of Adding H.F. (Readers' Problems), 84 Foreign Programmes (Editorial), 423 By -Pass Condensers (Readers' Problems), 474 Diode Detection (Editorial), 25 Forgotten Volts (Readers' Problems), 498 12120 PFcOPcR Y U.S. AiR FO ZE www.americanradiohistory.com Formo Densers, 234 Kit Constructors' Notes, 92, 202,' 221, 306, 361, 433, Neutralising Condenser, Short-Circuited (Readers' " 1928 " Log Condensers, 603 463, 533, 641 Problems), 684 Screened Grid Three, The (Kit Constructors' Constructors' Problems, 204, 222, 307, 362, 642 Condenser, Some Uses for the, 532 - the Screen -Grid Valve (Readers' Problems), 571 463 -" Kusha " Pick -up Arm, 78 - Notes), - Unnecessary (Readers' Problems), 498 Frame Aerial, A, 320 -New A.C. Valves, The, 682 Aerial Details (Readers' Problems), 660 448 - - Aerial Dimensions (Readers' Problems), 296 46, 77, 104, 134, " New All -Wave Four," (Readers' Problems), Laboratory Tests, Wireless World, -Free Grid Bias (Readers' Problems), 190 283, 335, 353, 392, 438, New Apparatus, 410, 513, 565, 624 160, 186, 206, 233, 318, French Valves, Some Interesting, 465 Broadcast Licence Conditions (Editorial), 395 459, 492, 537, 647, 672 - Call Signs and Stations Identified, 646 Further Data Wanted (Readers' Problems), 684 v. S. G. Brown, Ltd. (The Lektophone Corporation - Cossor Melody Maker (Kit Constructors' Notes), Speaker), 208 Cone Loud 92 Gambrell Twin Fuse Unit, 206 Lewcos Fixed Potentiometer, 410 Empire Receiver (Readers' Problems), 296 " Sixpin Coils, 335 Gauge of Resistance Wire, Estimating 158 " Super - Era in H.F. Amplification, A (Editorial), 423 the, 662 Gecophone Grid Batteries, 514 L.F. Amplifier, Designing 1 L.F. Stages, 214 Year Resolutions (Editorial), H.T. Dry -Cell Batteries, 672 Amplifier following Two News from the Clubs, 20, 42, 130, 236, 253, 304, 467. 603 - Choke Inductance (Readers' Problems), 320 - Loud Speaker Movement, 536, 552 83 - World -Wide Screen -Grid 4 (Broadcast Receivers), or H.F. ? (Readers' Problems), 91 Pictures at Sea, - Reaction (Readers' Problems), 112, 448 - 128 673 -" Nipsit " Time -Saving Screwdriver, Solidified Type, - Stage, An Extra (Readers' Problems). 448 " Geeko " Unspillable Accumulator, Problems), 660 No Grid Bias (Readers' Problems), 112 410 Stage, Eliminating an (Readers' North Africa, Radio in, 196 -Licences, Transmitting (Readers' Problems), 394 Gilman Floating Cone, 410 Norton Moving Coil Loud Speaker, 624 Glow Discharges, The Use of (A New Loud Speaker), 64 Liasen " Super " Transformer, 236 Not a Private Quarrel (Editorial), 55 Goodmans' Picture Relay, 187 Litz Wire (Readers' Problems), 189 Portable Set Cone Unit, 602 Loading Coils, 54 -Gramophone Amplifier (Readers' Problems), 111, 522 Loewe Type O.E. 333 (Broadcast Receivers), 79, 15R " Obeta " H.T. Batteries, 647 Records for the, 268 Log Condensers, Formo " 1928," 603 Octron Series, The (Valves We Have Tested), 655 Amplifier, Supreme " Transformers, 46 - Pick -Ups, 259 Long -Wave " Everyman Four " (Readers' Problems), " O.K. Charger, 47, 513 Gramophones, Radio, 245 112 Oldham T.T. Battery Grantona Cones, 438 Lotus Dual -Wave Coils, 565 H.T. Units, 131 Discharges), 64 -Old Lamps for New (Editorial), 547 Problems), 296 Loud Speaker, A New (the Use of Glow Grid Bias from the Mains (Readers' Problems), 296 Bias (Readers' Problems), 11.2, 140, 190 Speaker Baffle, Fire Screen, 439 Problem, The (Readers' Pro- - Timer, An (Readers' Problems), 237 - Leak and Condenser Holder, P.M., 537 Speaker Connections (Kit Constructors' - Problems), 642 - blems), 642 Omnibus Wiring (Patent), 226 - Leak Failure (Kit Constructors' Resistances (Readers' Problems), 83 Speaker Diaphragms (Patent), 558 One Meter, Many Purposes, 86, 131, 162 - Voltage, Control of (Readers' Problems), 320 Speaker Movement, Gecophone, 603 Operation at a Time, 214 - Speaker Polarity (Readers' Problems), 112 " Open " Grid Circuit, An (Readers' Problems), 237 -- Speaker Response Curves, 216 Oscillation, On the Verge of (Readers' Problems), 448 de Luxe Screened Four, 583 Halcyon - Speakers, Two, 213 Osram Music Magnet, 202 Hartley Circuit, Improving, 631 Out and About with a Portable, 4U2 Headphone Work, For (Readers' Problems), 546 Output Choke, 53 Arma- The, " Hegra " Cabinet Loud Speaker and Balanced (Kit Constructors' Problems) 336 Magnification; Too Much ture Unit, 362 P. and F. Ideal Terminal, 492 Loud Speaker Unit, New, 672 Parallel -Feed H.F. Couplings (Readers' Problems), 660 Magnum Auto -Fuse, 625 . -Hellesen Batteries, 161 473 283 " Parallel " Reaction (Readers' Problems), A New Era in (Editorial), 423 L.F. Choke, H.F. Amplification, -Mains, D.C. Supply Units (Patent), 244 Paris Fair, Radio at the, 627 Amplification, Short -Wave (Readers' Problems), D.C. Trouble with (Readers' Problems), 190 Patent Novelties, 226, 244, 401, 558, 652, 675 - 84 661 Re- Patents, Wireless (Editorial), with Modern Valves, Aperiodic, 173 Screened Dimic Three, The (Broadcast Amplification ceivers), 568 Paying for Results (Readers' Problems), 238 - Amplifier, A Mixed (Readers' Problems), 166 Problems), 54 Pentode and Pick-Up (Readers' Neutralised (Readers' Problems), 189 Transformer Material, 565 Amplifier, - Transformers, Small, 610, 649 and Power Amplification, 60 - Amplifiers, Screen -Grid (Readers' Problems), 369 - the (Readers' Problems) Charts), - Resistance Coupling and Design (Useful Data - Difficulties of Adding (Readers' Problems), 84 Transformers, The - 238 - 363, 441, 540 L.F. ? (Readers' Problems), 83 or Valve Current from the, 180 The (Readers' Problems), 189 - Resistance of a Coil when Diameter of Wire is 190 1, 513 - Two, Adding H.F. (Readers' Problems), -Mainten H.T. Eliminator, Model D.C.M. Optimum, Approximate (Useful Data Charts), 97 -" Pentode Two," The, 53, 166 Resistance to D.C. Resistance of a Coil, Ratio of Man -made Static 476 Marconi and Osram " Point 8 " Series (Valves We Pentodes, Ediswan (Valves We Have Tested), 342 - (Useful Data Charts), 120 190 Have Tested), 419 Periodic Interference (Readers' Problems), Stage for a Portable (Readers' Problems), 112 Have Tested), Phantastra Loud Speaker, 624 Stage, Modified (Readers' Problems), 394 and Osram S.215 Valve (Valves We - 136 Philips, Type 2,802 (Broadcast Receivers), 542 - Stages, Three (Readers' Problems), 111 and Osram Valves, Two New (Valves We Have Photo -Electric Cell, The, 557 - Stopping (Readers' Problems), 84 106 - Tested), 19 Physical Society's Annual Exhibition, The, Transformers, The Design of, 548, 617 (Kit Constructors' Problems), 296 Patents (Editorial), 141 Pick -Up and Pentode High Resistance Connections (Readers' Problems), - 160 307 600 Marconiphone Universal Output Transformer, 103, Hints and Tips for Portable Users, Impedance (Readers' Problems), 370 Connections (Readers' Problems), 296 H.L. 610 and D.E.L. 610 (Valves We Have Tested), 19 Matching Valve Mazda Series of 4 -Volt Valves, The (Valves We Have Fitting a, 265 Holzman Pocket Voltmeter, 493 -Pick -Ups, Gramophone, 259 H.T. Batteries, Dry Cell, 48 - Tested), 156 2 Valves (Valves We Have Tested), Picture Receiver, Building a, 2, 26 for the Tropics, 54 Series of -Volt - 95 Receiver, Carrier for, 135 -Hunt's Measuring Instruments, 104 518 - Receiver Contacts, 186 -Volt Series, The (Valves We Have Tested), " Hypermu " Transformer, 625 -6 Screened Three (Kit - Receiver Kit, 514 McMichael Home Constructors' Constructors' Notes), 641 Receiver Parts, 187, 460, 493, 538, 566 I.F. Amplifiers (Readers' Problems), 546 581 - Receiver, The (Readers' Problems), 190 Super Screened Four, L.F. Choke, 161 Reception, 99 Igranic -Measuring Instruments, Hunt's, 104 ti -Parent Midget Jacks, 566 Mechanical Problem, A (Readers' Problems), 660 Pictures by Beam Wireless, 192 - Pentoformer, 353 Problems), 608 Piezo Crystals, Cutting (Patent), 558 Megavox Loose-Coupler (Readers' - Public Address System, 673 Problems), 571 -Electric Alarm, A (Patent), 226 Modification (Readers' - Screened Condenser, 648 Problems), 394 -P.M. Grid Leak and Condenser Holder, 537 - Reaction Control (Readers' - Type " J " Transformer, 411 for the (Readers' Problems), Polar Components, Two New, 233 - Three, Milliammeter -Improving Detector Efficiency, 524 H.F. Chokes, 354 - 166 Selectivity, 510 for the, 54 - Ideal " Drum Control Condenser, 672 " Megavox," Two -Volt Valves - the Hartley Circuit, 631 Short Wavelengths, The Cossor Polymet Products, 105 Melody Maker on Ultra -Increased Volume on Short Waves (Readers' Pro- Notes), 221 " Polymet " Tubular Condensers, 647 (Kit Constructors' blems), 572 Merger, The New (Editorial), 297 " Portable " Circuit, A Good (Readers' Problems), 808 Increasing Condenser Capacity (Readers' Problems), " Metaplac " Wireless Panels, 514 Portable, " Decoupling " a (Readers' Problems), 684 344 Microphone and the Voter, The, 36 Direction Finder, 614 Eliminator Voltage, 213 ? - H.F. Stages for a (Readers' Problems), 112 Microphonic Action or L.F. Reaction 448 Heated Valves (Readers' Peoblems), 360 412 - Out and About with a, 402 Indirectly Milliammeter and the Receiver, The, Indoor Aerials (Readers' Problems), 84 Where It Fails (Readers' Problems), 238 Sets, Buyers' Guide to (1929), pp. 585 to 599 Instability (Readers' Problems), 272 Problems), 166 - The Europa, 500 - for the Megavox Three (Readers' Interaction between Input and Output, 214 - The Most Suitable (Readers' Problems), 112 The Lightest (Readers' Problems), 421 Periodic (Readers' Problems), 190 of Wire or - The Modern, 574 Interference, -Minimum H.F. Resistance, Diameter Disconnection, An (Readers' Problems), of Data Charts), 43 - Wireless World S.G. Multiple Valve, 396 Intermittent Strand to Give Coil (Useful - Components for (Apparatus Reviewed), 602 545 Mirrors and Portables (Readers' Problems), 84 Portables, Interstage Reaction (Readers' Problems), 369 Parts for the Picture Receiver, 187 Need no Apologies, 604 Miscellaneous 579 Inventor and the Manufacturer, The, 556 Modified H.F. Stage (Readers' Problems), 394 Reviewed, Representative, " Ipso " H.T. Batteries, 538 652 -Power Circuit Interference (Kit Constructors' Pro- Mounting Condenser Plates, Patent, Irish Free State Amateurs, New Call Signs for, 172 Moving Coil, Design Data for the, 561 blems), 307 Iron-Cored Chokes Carrying D.C., The Design of Mullard Master 3, The (Kit Constructors' Notes), 306 Circuit Interference, Eliminating (Readers' (Useful Data Charts), 688 Multi -Stage Valves (Patent), 244 Problems), 140 Is All Well with the B.B.C. ? (Editorial), 609 Musical Choke, A (Readers Problems), 447 Line Interference (Readers' Problems), 684 Dials, 492 - or Lighting Mains (Readers' Problems), 140 Iso Mysterious Fault, A, 53 Transformers, 54 -Prague Conference, The, 509 Japanese Amateurs, 348 Is it Sound ? 638 Jelectro, 411 Nationality Prefixes, 414 Plan, 191 - Wavelength Plan, The, 437 Nation Shall Speak Peace Unto Nation (Editorial), New Service, 73 Pretty Idea, 513 Kilocycles per Degree (Readers' Problems), 447 Nauen to Buenos Aires-A Telephony Neophone Loud Speaker, 78 Primary-cum-Reaction Windings (Readers' Problems) " Kilo -Mag Four," The (Readers' Problems), 571 659 of, 220, 426 Neutralise, Why We, 644 " King's," Centenary, 370 Programmes from Abroad, 15, 37, 66, 100, 124, 152, " Kirkifier," A Description of the (The Diode Rectifier), Failure to (Readers' Problems), -Neutralised H.F. Amplifier (Readers' Problems), 189 176, 198, 228, 254, 286, 308, 338, 357, 381, 406 32 4 www.americanradiohistory.com Programme Time Switches, 616 Series Aerial Condenser (Kit Constructors' Problems), Triotron Loud Speaker Unit, 648 Protecting Inductive Windings (Readers' Problems), 307 Series, The (Valves Tested), 470 474 Sets for Abroad (Readers' Problems), 473 -Trix Portable Two, 584 Protection for Valves (Readers' Problems), 369 "S.G. Portable," Modified (Readers' Problems), 474 Truce, A (Editorial), 85 Public Address System, Igranic, 673 Regional Receiver, The Wireless World, 322, Tudor " Monolt " Unit, 538 Push -Pull, The Theory of, 114, 505 - 349, 441 Tuning Control (Patent), 244 Pye Pentode Output Transformer, 459 Valve and Radiation (Readers' Problems), 422 " Two -Circuit Two," 143 Portable, The, 580 -Short Aerials (Readers' Problems), 24 -Circuit Two," The (Readers' Problems), 320 - Short- Circuit, L.F. (Readers' Problems), 546 -Two Super H.F. Stages (Readers' Problems), 831 " Quest " Combination Panel Brackets, 438 Circuited H.T. Supply (Readers' Problems), 632 Two -Volt Valves for the " Megavox," 54 " Quint " Biflex Earth Tube, 392 - Circuited Neutralising Condenser (Readers' - Problems), 684 Radio-Gramophone Combination, 240, 290 -Wave Adaptor (Readers' Problems), 238 Ultra -Short Wavelengths (Readers' Problems), 498 -. 362 " Radio -Gramophone Combination," The (Readers' -Wave " Everyman Four," 632 -Short Waves (Kit Constructors' Problems), -Unnecessary Complications (Readers' Problems), 474 Problems), 421 - Wave H.F. Amplification (Readers' Problems), 84 Radio Gramophones, 245 - Waves, Increased Volume on (Readers' Pro- Unstable " A.C.3," An (Readers' Problems), 112 " Radiolene " H.T. Battery, Type W. 510,872, 439 - blems), 572 Useful Data Charts, 43, 97, 120, 209, 318, 363, 441, 540, 668 " Raytrak " Pick -Up Carrier, 439 Sibilants, Badly Reproduced (Readers' Problems), 84 24 R.C. Coupler, An, 112 Siemens New Grid Cell, 319 Using the Abacs (Readers' Problems), Reaction Circuit, Simple (Readers' Problems), 237 Portable Set H.T. Batteries, 335 Utility Relay, 207 Condenser Capacity (Readers' Problems), 474 -Sifam H.T. Fuses, 647 - Control, Differential (Readers' Problems), 572 Signal Frequency Amplifier, The (Readers' Problems), Valve as Anode Detector, The, 279, 326 an Bend -Readers' Problems, 24, 53, 83, 111, 140, 166, 189, 213, 684 as an Anode Bend Detector, The (Readers' 237, 272, 296, 320, 344, 369, 394, 421, 447, 473, Signs of Activity (Editorial), 547 - Problems), 474 497, 522, 545, 571, 608, 631, 659, 883 Simple Conversion, A (Readers' Problems), 320 Current from the Mains, 180 Rebuilding the " Everyman Four," 213 Reaction Circuit (Readers' Problems), 237 - Data, Interpreting, 175 Receiving Broadcast Pictures (Patent), 558 Six -Sixty " Mystery " Receiver, The (Kit Con- - Holder Connections (Readers' Problems), 632 Records for the Gramophone Amplifier, 268 structors' Notes), 361 - Impedance, Matching (Readers' Problems), 370 Red Diamond Wave Change Switch, 460 Slow Starter, A (Readers' Problems), 683 Makers' Benefit Circuits (Readers' Problems), 51 Reducing Aerial Loading (Readers' Problems), 660 Small Mains Transformers, 610, 649 - Power, Choosing for Loud Speaker, 298 Rees Mace Twin Screened Grand (Broadcast Re- Soft Valve, A (Readers' Problems), 421 - Tester, Ferranti, 459 ceivers), 667 Something for Nothing, 522 The (Editorial), 167 " Reflex " Eliminator, A (Readers' Problems), 344 South Kensington Receiver, The (Readers' Problems), -Valves, French, 465 " Regional " Receiver, Modified (Readers' Problems), 83 Indirectly Heated (Readers' Problems), 369 370 Spindles for Picture Receivers, 460 - Protection for (Readers' Problems), 369 Regional Scheme and the Future of Reception Stability by Grid Damping ? (Kit Constructors' We Have Tested, 19, 75, 95, 137, 156, 342, 419, (Editorial), 499 Problems), 307 470, 518, 655 Relative Sensitivity (Readers' Problems), 497 " Stal " L.F. Transformers, 318 Variable Condenser, Art et Technique, 392 Renewing Aerial Wire (Readers' Problems), 237 Stanfield Converter, 459 Condenser (Readers' Problems), 111 Representative Portables Reviewed, 579 Sundays Only (Readers' Problems), 370 -Vogt Electrostatic Loud Speaker, 553 Resistance and Transformer Coupling (Readers' Pro- Suppressing Personality (Editorial), 297 Voltage Drop (Readers' Problems), 659 blems), 498 Swings and Roundabouts, 301 Hints on Regulating and Measuring (Screen Grid Coupling and the Pentode (Readers' Problems), Switches, Time, 616 - Volts), 70 - 238 Switching Over (Readers' Problems), 421 Volts, Dropping, 213 Equivalent of a Tuned Plate Circuit (Useful Safe L.F. (Readers' Problems), 546 Volume Control, Post- Detection (Readers' Problems), - Data Charts), 316 -Sydney Talks to New York, 119 683 Excessive H.F. Locating (Readers' Problems), Systematic Testing (Readers' Problems), 370 Control, Pre- Detection (Readers' Problems) 473 - 447 - Wire, Estimating the S.W.G., 158 Talking Films, 376 Reversed Coil Connections (Readers' Problems), 631 Tapped Aerial Tuning Unit, 318 Water Ripples and Wireless Waves, 56 R.I. and Varley Straight Line Transformer, 354 Telephone in Series (Readers' Problems), 54 Wates Universal Test Meter, 46 -Varley Bi- Duplex Transformer, 186 Telephony, World -Wide, 313 Waveband Switching (Readers' Problems), 497 - -Varley Multi-Cellular H.F. Choke. 319 Television (Editorial), 273 Wavelength Range, Extending (Readers' Problems), - -Varley " Straight Line " Transformer, 283 The Postmaster General's Statement (Editorial), 421, 497 -Ripault Wet H.T. Battery, 47 371 Wavelengths, The New, 21 Rotor -Ohms, 493 The Postmaster General's Statement, 380 Wavemeter, Amateur Band, 493 Rule of Thumb, A, 166 Terminal Voltage (Readers' Problems), 546 Wavetrap Adjustments (Readers' Problems), 545 Russian Amateur Call-Signs, 528, 666 Testing an Z.F. Transformer (Readers' Problems), 572 " Wearite " Filter Units, 319 Condensers (Readers' Problems), 370 What Gauge is it ? 158 Who's Who in the Ether, 7, 149, 214, 238, 264, 330, 422 Safe Set, A (Readers' Problems), 448 - Unit, A (Readers' Problems), 111 "Schools' Demonstration Receiver" (Readers' Pro- -" They Also Serve," 539 Who in the Ether (Answers to Correspondents), - 197, 264, 294, 301, 330, 356, 474 blems), 571 Thordarson Choke, 318 Wireless Demonstration Receiver, The, 372, 427 Three H.F. Stages (Readers' Problems), 111 and the Weather, 389 Scientific Wiring (Readers' Problems), 498 Too Much Magnification (Kit Constructors' at Westminster, 462 Problems), - Camp, 416 Scott's Dual-Range Coil, 647 36.2 - Diary, The, 214 Screen for Europa III., 104 " Topping " Accumulators (Patent), 401 - in Eastern Europe, 482 Screen -Grid " A.C.3," A (Readers' Problems), 237 Trade Notes, 47, 161, 207, 284, 336, 493, 538, 599 - Patents (Editorial), 661 Grid H.F. Amplifiers (Readers' Problems), 369 Transformer, Bi-Duplex, R.I. -Vazley, 186 - Patents, 675 Screening Boxes (Readers' Problems), 320, 344 Transformers, Design of H.F., 548, 617 -Wiring, Scientific (Readers' Problems), 498 Selectivity (Readers' Problems), 190 L.F. Testing (Readers' Problems), 572 Wirt Lightning 392 and H.F. Transformer Windings (Readers' - Small Mains, 610, 649 Arrester, in Dark - Problems), 572 -Transients alias " Attack," 346, 385 Working the (Readers' Problems), 24 Improving, 510 Transmission of Sidebands by a Tuned Circuit (Useful " World at Your Finger Tips, The," 489 - Lack of (Readers' Problems), 166 Data Charts), 209 -Time Indicator, A New, 480 - -Wide Telephony, 313 - Limitations of (Readers' Problems), 659 Transmitters' Notes and Queries, 12, 31, 118, 278, -Worth Waiting For (Readers' Problems), 571 Self- Contained Valve, A (Patent), 652 348, 380, 414, 528, 613, 666 Sensitivity and Selectivity Needed (Readers' Pro- Transmitting Licences (Readers' Problems), 394 blems), 572 T.R.C. Transformers, 438 Zampa Floating Cone, 134

ILLUSTRATIONS

Abate, Wireless World (Useful Data Charts), 44, 45, 98, Appleton, Professor E. V. (Measuring Signal Strength), Blind Listener, For the (" Braille Radio Times "), 623 121, 210, 317, 364, 365, 442, 443, 541, 669, 670 52 British General Aerial Tuner, 318 A.C. High Frequency Valve, How to Connect Heater Armoured Car Wireless, 379 General " Super Shrouded " Transformer, 207 and Cathode (Diagram), 683 Art et Technique Variable Condenser, 392 - Industries Fair, Radio at the, 223, 224, 225, 226 Valves, The New, 682 Artificial Resistance in Oscillatory Circuit, Position of - Wireless Dinner Club, Annual Dinner of, 405 -Acid Level Indicator for Accumulators, 401 (Diagram), 447 -Broadcasting from the Heart of Europe (Lausanne), 330 A.C. /S. Valve, Modified Circuit of (Diagram), 545 Ashbridge, Mr. Noel (Capt. Eckersley's Successor), 653 " Broadcasting House " of Spain, 391 Aerial Circuit fdr " Megavox " Receiver, Tuned At Aix -la- Chapelle, 654 Broadcastingng in Eastern Europe (Zagreb, Yugo -Slavia), (Diagram), 497 Automatic Control, Relay Arrangement for (Diagram), Coupling, Continuously Variable (Diagram), 631 189 in Sweden (Stockholm), 487 -Aermonic Screen Grid Valve Holder, 602 Avometer, The, 187 - of To-morrow, The Broadcasting House, 626 Afghanistan, Hostilities in (Wireless Station at Kabul), -Broadcast Receiver for the Deaf, 495 41 Receivers, 79, 128, 129, 302, 303, 304, 542, 543, Aircraft Control at Croydon, Radio, 185 Baker's Trigger Release for Use in Picture Receivers, - 568, 569, 687, 668 Aix -la- Chapelle, At, 654 566 Buda -Pest, Hallo ! Hall It, 296 All Electric Amplifier, 634, 635, 636, 637, 677, 678, B. and J. Aerial Inductance for Europa III., 104 Buenos Aires, Nauen to (Short -Wave Beam Trans- 679, 680, 681, 682 -- and J. H. F. Transformer for Europa III., 104 mitting Stations) (Diagrams), 73, 74 " Always " Potential Divider, 613 Bayliss Power Chokes, 624 Bulgin High Frequency S.G. Choke, 284 Amateur Transmitting Stations B.B.C,'s Northern Nerve Centre (Manchester), 517 Quick Break Switch, 411 F1M at Bourges, 613 " Beamu " Pick -Up Carrier, 206 -Burndept Cabinet Cone Loud Speaker (Model 1676), 585 F8XZ at St. Dizier, 528 Belgrade, Europe's Youngest Broadcasting Station, 468 -- Empire Screened Four (Broadcast Receivers). Ampliformer, The, 234 Berclif H.F. Choke, 393 302, 303, 304 Annual Dinner of British Wireless Dinner Club, 405 Bias of 0.5 Volt, A Simple Way of Providing a (Dia- Screened Portable, 582 Aperiodic H.F. Amplification with Modern Valves gram), 389 - Turntable, 603 (Diagrams), 173, 174 Bi- Duplex Transformer, R.I. -Varley, 186 Buyers' Guide to Portable Sets, 1929, 585 -599 5 www.americanradiohistory.com " Cameo " Riverside Portable Case, 602 Goodmans' Picture Relay, 187 Mazda Series of 4 -Volt Valves (Curves) (Valves We " Carco " Switches, 625 Portable Set Cone Unit, 602 Have Tested), 156, 157, 158 Centralab Products, 135 -" Graf Zeppelin," Wireless Cabin in the (Short Waves Series of 2 -Volt Valves (Valves We Have Tested), Chakophone de Luxe Aerial Tuner, 393 from the Air), 437 - 95, 96 Charts, Useful Data, 43, 44, 45, 98, 120, 121, 122, 209, Gramophone Pick -Ups, 259, 260, 261, 262, 263, 264 -6 -Volt Series (Valves We Have Tested) (Curves), 210, 211, 316, 317, 363, 364, 365, 441, 442, 443, Gramophones, Radio, 245, 246, 247, 248, 249, 250, 518, 519, 520 540, 541, 669, 670, 671 251, 252, 253 McMichael Home Constructors' Screened Three (Kit Choosing a Power Valve for the Reed -Driven Loud Grantona Cones, 438 Constructors' Notes), 641, 642 Speaker (Diagram), 298, 299, 300, 301 Grid Bias from the Electrostatic Charge Stored in a Super Screened Four, 581 the Right Valve, 168, 169, 170, 171, 172 By -Pass Condenser (Diagram), 394 -Measuring Signal Strength (Professor E. V. Appleton), -Clear Glass Valve (Diagram), 401 Circuit of the " Europa III." Receiver, Modified 52 Cleary Wet H.F. Batteries, 206 - (Diagram), 24 " Megavox " Receiver, Tuned Aerial Circuit for Clix Power Plug and Socket, 134 (Diagram), 497 Wood-Screw Sockets Parallel 353 Met -Vick Piezo -Electric Alarm, Circuit of, 226 and Pin Plugs, Halcyon de Luxe Screened Four, 583 -Colato Cabinet Loud Speaker, 353 Microphone and the Voter, The, 38 " Hegra " Balanced Armature Unit, 336 Collett's " Eze -Way " Pulley, 207 Milliammeter and the Receiver, The (Diagrams), 412, Cabinet Cone Loud Speaker, 336 413, 414 Collinson Picture Receiver Spindle, 638 - Loud Speaker Unit, New, 672 Modern Portable, The, 574, 575, 576, 577 " Coltags, ' 603 -Hellesen Grid Bias Batteries, 161 H.F. Amplification with Columbia H.T. Battery, Type No. 4721, 460 H.F. Amplification with Modern Valves, Aperiodic Valves, Aperiodic Colvergraph, The, 331, 332, 333, 334 - (Diagrams), 173, 174 (Diagrams), 173, 174 Cone Loud Speaker (Hopkins' Patent), 208 Modified Circuit of A.C. /S. Valve (Diagram), 545 Amplifying Unit for " Pentode Two " (Diagram), Grid Circuit of the " Europa III." Receiver Continental Giant, A (Lahti Station, Finland), 536 - 190 Continuously Variable Aerial Coupling (Diagram), 631 - (Diagram), 24 Couplings, Parallel -Feed (Diagram), 660 Room, A German (Königsberg), " Monolt " 6 -Volt Unit, Tudor, 538 Control 678 - Stopping (Diagram), 84 -- More Amplification from Screen -Grid Valves (Dia- Room at Oslo, The, 674 Transformer, Looseley -Coupled (Diagram), 83 -Cossor L.F. Transformer, 672 grams), 424, 425, 456, 457, 458 - Transformers, The Design of (Diagrams), 548 Melody Maker on Ultra -Short Wavelengths (Kit Moving Coil, Design Data for the (Diagrams), 561, - 549, 550, 617, 618, 619, 620, 621 - Constructors' Notes), 221, 222 562, 563 Hinkler, Mr. Bert, and Mr. C. G. Allen (Antipodean the Microphone, 13 - - Melody Maker, The New (Kit Constructors' 285 M.P.'s and Concerts), Mullard Master 3, The (Kit Constructors' Notes), 306, Notes), 92, 93 Holzman Watch -Type Voltmeter, 493 Croydon, Radio Aircraft Control at, 185 307 Home Constructors' Picture Receiver, 99 Valve Portable, Wireless World S.G., 396, " Crusader " Motor Yacht (A Private Yacht Station), 208 Multiple Hopkins Patent Cone Loud Speaker, 397, 398, 399, 400 305 H.T. Batteries, Dry Cell (Curves), 48, 49 Meter, 105 Hunt's Moving Coil Hauen to Buenos Aires (Short Wave Beam Trans- Danish Broadcasting, 643 " Hypermu " Transformer, 625 Deaf, Broadcast Receiver for the, 495 mitting Stations), (Diagrams), 73, 74 Decoupling " a Portable (Diagram), 684 Nearing Perfection (" Fultograph " Reproductions), Designing the L.F. Amplifier, 662, 663, 664, 665, 666 " Ideal " Drum Control Condenser, Polar, 672 1:33 D.C. Junior Eliminator, The (Diagram), 632 Ideal Spring Connector, P. and F., 492 Neophone Loud Speaker, 78 Demonstration Receiver, The School's, 372, 373, 374, Igranic L.F. Choke, 161 New A.C. Valves, The, 682 376, 427, 428, 429, 430, 431 -Patent Midget Jack, 666 News Pictures at Sea, 91 Detex R.C.C. Unit, 186 - Pentoformer, 353 " Nipsit " Time -Saving Screwdriver, 673 Diamond 2 -Volt, 40 A.H. L.T. Accumulator, 565 Public Address System, 673 North Africa, Radio in, 196 Differential Reaction Control (Diagram), 572 - Screened Condenser, 648 Northern Nerve Centre, B.B.C.'s (Manchester), 517 Diode Rectifier (Diagram), 23. - Type " J " Transformers, 411 Norton Moving Coil Loud Speaker, 624 Direction Finder, Portable, 614, 615, 616 -Improving Detector Efficiency (Curves), 524, 525, 526, Nürnberg Broadcasting Station (Heard too Easily?) - Finder, The Latest, 535 527, 528 355 Disto Filler for " Topping Up," 492 Selectivity (Diagrams), 510, 511 Dry Cell H.T. Batteries ( Curves), 48, 49 -Instability, Locating (Diagram), 272 - " (Theta " Large Size H.T. Battery, 648 Dubilier H.F. Chokes, 77, 78 " Ipso " 60 -Volt Dry Cell Battery, 538 Octron Series, The (Valves We Have Tested), Curves, - " Toreador Screened Grid Four," 633, 534 Iso Dials, 492 655, 656 Dynamic Resistance (Diagram), 274, 275, 276, 277, 278 " O.K. Supreme " Transformer, 46 Oldham H.T. Battery Charger, Type A.C., H.T.1, 513 " J " Transformers, Igranic Type, 411 Edlswan Pentodes (Valves We Have Tested), 342, 343 H.T. Trickle Charger for H.T. Mains, 47 Edwards Portable Set Accumulators, 603 - 10-Volt Unit with Air- Spaced Cells, 134 Ekco H.T. D.C. Eliminator, Model 3 F.12, 537 Kirkifler," A Description of the (The Diode Rectifier), -One Meter, Many Purposes, 86, 87, 88, 89, 131, 132, " Electramonic D.C. H.T. Eliminator, 625 32, 33, 34, 35 133, 162, 163 Eliminators and Battery Chargers, 666 Kit Constructors' Notes, 92, 93, 202, 203, 306, 307, Oslo, The Control Room at, 674 -Eliminator for Two -Valve Sets, An, 529, 530, 531 361, 362, 433, 434, 435, 463, 484, 533, 534, 641, Osram Music Magnet, 20.2, 203 Elodén Cabinet Type Loud Speaker, 284 642 Out and About with a Portable, 402, 403 " Elodén Compressor " Loud Speaker, 284 Klagenfurt Calling, 601 Eton " British Valves," Curves (Valves We Have Königsberg (A German Control Room), 676 P. and F. Ideal Spring Connector, 492 Tested), 75, 76 " Kusha " Pick -Up Arm, 78 Parallel -Feed H.F. Couplings (Diagram), 680 Primary H.T. Battery, 160 Paris Fair, Radio at the (Exhibits), 627, 628, 629 Europa Portable, The, 500, 501, 502, 503, 504 Pentode and Power Amplification, The (Curves), 60, " Europa III.," B. and J. Aerial Inductance for, 104 Lahti Station, Finland (A Continental Giant), 536 61, 62, 63 Europa III., B. and J. H.F. Transformer for, 104 Latest Direction Finder, 635 " Pentode Two," H.F. Amplifying Unit for (Diagram), Lock- Atkinson Screen for Building the, 104 Lausanne, HB2 (Broadcasting from the Heart of 190 -" Europa III." Receiver, Modified Grid Circuit of Europe), 330 Modified Reaction Control System for Two," the (Diagram), 24 Lees -Smith, Mr. H. B. (The New P.M.G.), 646 - the (Diagram), 53 " Exact " Tuning Devices, 105 Lewcos Fixed Potentiometer, 410 Phantastra Loud Speaker, 624 Exide Unspillable Accumulator, 602 " Super " Sixpin Coils and H.F. Transformers, Philips Type 2,802 (Broadcast Receivers), 542, 543 - 335 Extra L.F. Stage for S.G. Regional (Diagram), 448 Photo -Electric Cell, The, 557 L.F. Amplifier, Designing the, 662, 663, 664, 665, 666 Physical Society's Annual Exhibition, Exhibits at, Choke, Igranic, 161 106, 107, 108 Ferranti Screened Grid Three, The (Kit Constructors' - Choke, Magum Centre -Tap, 283 Pick -Up, A Short- Circuited (Diagram), 296 Notes), 433, 434, 534 -Lissen " Super " Transformer, 233 -Up, Fitting a, 265, 266 Valve Tester, 460 Locating Instability (Diagram), 272 -Films, Talking, 376, 377, 378 -Picture Broadcasting Equipment, New, 159 Lock -Atkinson Screen for Building the Europa III., 104 Receiver, Building a, 2, 3, 4, 5, 6, 26, 27, 28, 29, Fire -Screen Loud Speaker Baffle, 439 Lodge, of Sir Oliver (New Picture Broadcasting Fitting -Up, 265, 266 Portrait - 30, 31 a Pick Equipment), 159 Receiver Carrier, 135 Flat -Dwellers' A.C. Three, 450, 451, 452, 453, 481, Loewe Receivers), 79, 80 482, 483, 484, 485, 486 Type 0.E.333 (Broadcast - Receiver Spindle, Collinson, 538 Log Condensers, Formo " 1928," 603 Dr. A., F.R.S. (A New Year Honour), 258 - Receiver, The Home Constructor's, 99 Fleming, J. Aerial 565 -- Wiring, 226 Lotus Q.A. Dual -Wave Unit, Receiver, Utility Set of Contacts for, 186 Flewelling Method of Loud Speaker, A New (The Use of Glow Discharge) 1M, 613 - Receiver, Utility Trigger Release for, 493 F Bourges (An Active French Station), (Diagrams), 64 528 - Reception (Results with a Home Constructor's F 8XZ at St. Dizier, Baffle, -Screen, 439 Speaker Fire - Set), 72 Formo- Densors, 234 - Speaker Response Curves, 216, 217, 218, 219, 220 Pictures by Beam Wireless, 192, 193, 194, 195 " 1928 " Log Condensers, 603 People (Times Square, - Screened Grid Three, The (Kit Constructors' Speakers Address 350,000 Piezo- Electric Alarm, Circuit of Met -Vick, 226 -- - New York), 36 Notes), 463, 464 P.M. Grid Leak and Condenser Holder, 537 Four -Electrode Valve, Portable Set (Diagram), 421 " P.M.G.," The New (Mr. H. B. Lees -Smith), 646 Frame Aerial Circuit, Magnetically Coupled (Diagram), Magnetically Coupled Frame Aerial Circuit (Diagram), Polar Fixed Potentiometer with Two Tappings, 233 140 140 " Ideal " Drum Control Condenser, 672 Fraser, Capt. Ian, 512 Magnum Auto Fuse, 625 - Standard and Short-Wave H.F. Chokes, 354 French Valves, Some Interesting, 465, 466, 467 Centre Tap L.F. Choke, 283 -" Polymet " Condensers, 105 Fultograph Kit, The, 514 -Mains Screened Dimic Three, The (Broadcast Re- Tubular Condensers, 647 " Fultograph " Reproductions (Nearing Perfection), ceivers), 568, 569 - Wire -wound Resistances, 161 123 181, 182, 183 -Portable Sets, Buyers' Guide to (1929), 585 -599 Valve Current from the (Diagrams), -Mainten H.T. Eliminator, Model D.C.M.1, 513 -The Europa, 500, 501, 502, 503, 504 Cambrell Twin Fuse Unit, 206 Man -Made Static, 478, 477, 478, 479 The Modern, 574, 575, 576, 677 -Cell 673 Many Purposes, Meter, 86, 87, 88, 89,131, 132, 133, - Two, Trix, 584 Gecophone H.T. Dry Batteries, One Speaker 603 162, 183 - Wireless World S.G. Multiple Valve, 396, 397, Loud Movement, 9 We Have - 398, 399, 40O - 6- and -Volt Grid Batteries, 514 Marconi and Osram, D.E.L.610 (Valves -- World -Wide Screen Grid 4 (Broadcast Receivers), Tested), 20 " Portable " Circuit, A good (Diagram), 608 128, 129 and Osram, H.L.610 (Valves We Have Tested),19, Portable, " Decoupling " a (Diagram), 684 " Gecko " Unspillable Accumulator, 410 - and Osram " Point 8 " Series, 419, 420 Direction Finder, 614, 615, 616 ( 676 S.215 Valve, 137 - Out and About with a, 4U2, 403 German Control Room, A Königsberg), - and Osram Transformer, 160 - Set, Four Electrode Valve (Diagram), 421 Gilman Floating Cone, 410 -Marconiphone Universal Output 105 -Portables Need no Apologies, 604, 605 Glow Discharges, The Use of (A New Loud Speaker), " Universal " Transformer, (Diagrams), 64 Master 3, The Mullard, 306, 307 - Representative, 579, 580, 581, 582, 583, 584 6

www.americanradiohistory.com Position of Artificial Resistance in Oscillatory Circuit School's Demonstration Receiver, The, 372, 373, 374, Triotron Loud -Speaker Unit, 848 (Diagrams), 447 375, 427, 428, 429, 430, 431, 571 Series, The (Valves Tested), Curves, 470 " 513 Scientific Wiring (Diagram), 498 -Trix Portable Two, 584 Potential Divider, Always," Fotentiometer for Screen Grid Voltage Control (Dia- Scott's Dual -range Coil, 647 Tubular Resistances, Wirewound (" Polymet "), 161 gram), 344 Screened Grid H.F. Stage with Frame Aerial (Diagram), Tudor " Monolt " 6 -Volt Unit, 538 Power Valve for the Reed Driven Loud Speaker, 112 Tuned Aerial Circuit for " Megavox " Receiver Choosing a (Diagrams), 298, 299, 300, 301 Screen Grid Volts (Diagrams), 70, 71 (Diagram), 497 Prague Plan, Is It Sound ? 638, 639 Selectivity, Improving (Diagram), 510, 511 " Two -Circuit Two," 143, 144, 145, 146, 147, 148 Primary- cum - Reaction Winding (Diagram), 659 Self-Contained Valve, A (Patent), 652 Transformer -Coupled L.F. Stages (Diagram), 214 H.T. Battery, Eton, 160 S.G. Multiple Valve Portable, Wireless World, 396, -Private Yacht Station, A (M.Y. " Crusader, ") 305 397, 398, 399, 400 43, 44, 45, 98, 120, 121, 122, 209, 448 Useful Data Charts, Push -Pull, The Theory of (Diagrams), 114, 115, 116, Regional, Extra L.F. Stage for the (Diagram), 210, 211, 316, 317, 363, 364, 365, 441, 442, 443, 117, 505, 506, 507, 508, 509 - Regional Modified for Gramophone Ampli- -- 540, 541, 669, 670, 671 Pye Pentode Output Transformer, 459 fication (Diagram), 522 323, Utility Cylinder, The, 493 Portable, The, 580 Regional Receiver, The Wireless World, 322, Relay, 207 - - 324, 325, 349, 350, 351, 352 Set of Contacts for Picture Receiver, 186 565 Pick-Up, A (Diagram), 296 " Q.A." Dual -Wave Aerial Unit, Lotus, Short- Circuited - Trigger Release for Picture Receiver, 493 " Quest " Ccmbination Panel Brackets, 438 Waves from Siam, 461 - - Waves from the Air (Wireless Cabin in " Graf Radio Aircraft Control at Croydon, 185 - Zeppelin "), 437 Valve as an Anode Bend Detector, The, 279, 280, 281, Gramophone Combination, 240, 241, 242, 243, Siemens New Grid Cell, Size G.T., 319 282, 326, 327, 328 - 290, 291, 292, 293 Portable Set H.T. Batteries, 336 Current from the Mains (Diagrams), 181, 182, 183 - 245, 246, 247, 248, 249, 250, 251, Type No. 1203 Battery for the Loewe Set, 158 -Valves We Have Tested, 75, 76, 95, 98, 137, 156, 157, Gramophones, - 252, 253 Sifam H.T. Fuses, 647 342, 343, 419, 420, 470, 518, 655, 656 in North Africa, 196 Six -Sixty "Mystery" Receiver, The (K.C. Notes), Vogt Electrostatic Loud Speaker, 553, 554, 555 Radiolene H.T. Battery, Type W. 510,872, 439 361, 362 " Volcon " Reaction Condenser, 233 " Raytrak " Pick -Up Carrier, 439 Small Mains Transformers, 610, 611, 612, 649, 650, 651 Volume Control, Pre- Detection (Diagram), 473 R.C.C. Unit, Detex, 186 Southend Radio Society (Watching a Picture Grow), 94 Reaction Circuit, Simple (Diagram), 237 " Stal " Intervalve Transformer, 318 Water Ripples and Wireless Waves, 56, 57, 58, 59 Winding, Primary-cum- (Diagram), 659 Stanfield Converter, 459 Wates Universal Test Meter, 46 -Red Diamond Wave -Change Switch, 460 Stockholm Transmitter, The, 488 " Anode Filter Units, 319 " Wearite Reed -Driven Loud Speaker, Choosing a Power Valve Sweden, Broadcasting in (Stockholm), 487 Weather, Synoptic Chart received by Means of Fulto- for the (Diagrams), 298, 299, 300, 301 Switching Arrangement for Use with Two Loud graph, 389 Rees Mace Twin Screened Grand, The (Broadcast Speakers, Simple (Diagram), 213 What's Wrong with the Programmes ? 142 Receivers), 667, 868 L.F. Safe, 546 Who's Who in the Ether, 7, 8, 9, 10, 11, 12 Regional Station, Brookmans Park, 205, 559 -Sydney Talks to New York, 119, 120 Wireless and the Weather, 389 " Regional Three " Receiver with Pentode Output Camp, The, 416 Valve (Diagram), 370 - Recruits, 645 Regulating Input to First and Second L.F. Amplifying Talking Films, 376, 377, 378 - World S.G. Multiple Valve Portable, 396, 397, Valves (Diagram), 422 Tapped Potentiometer for Regulating Grid Voltage - 398, 399, 400 Relay Arrangement for Automatic Control (Diagram), (Diagram), 320 World S.G. Regional Receiver, 322, 323, 324, 325, 189 Telephony, World -Wide, 313, 314, 315 - 349, 350, 351, 352 Resistance Coupled L.F. Amplifier for Portable Testing Unit, A Simple (Diagram), 111 Wirt Lightning Arrester, 392 Receiver (Diagram), 474 Thordarson Type R -196 Choke, 318 " World at Your Finger Tips, The," 489, 490, 491 Ripault Wet Leclanche H.T. Battery, 46 " Toreador Screened Grid Four," The Dubilier (Kit -Time Indicator, A New, 480 R.I. -Varley Bi-Duplex Transformer, 186 Constructors' Notes), 533, 534 - -Wide Telephony, 313, 314, 315 -Varley Multi-Cellular H.F. Choke, 319 " Tote " Arrives, The, 436 - - -Varley " Straight-line," Transformer, 283 Transformers, Small Mains, 610, 611, 612, 649, 650, 651 Transients alias " Attack," 346, 347, 348, 385 Yacht Station, A Private (M.Y. " Crusader "), 305 Savage's Bakelite Bobbins for Transformer Con- " Transportable Set," An Early, 404 struction, 566 T.R.C. Transformer, 438 Zampa Floating Cone, 134

AUTHORS Abrahams, J. Godchaux, 7, 634 Kirke, H. L., 32 Vincer- Minter, N. P., 529

BaIbI, C. M. R., 495 Langfalls, P. 0., 643 Watson Watt, R. A., 389 Bell, D'Orsay, 515 Lucas, G. S., and C. G. Garton, 216 Branch, L. E. T., 561 Lupton, T. R., M.Sc., 662 Yeoman -Fobinson, E., 180

Castellein, A. P., 634, 677 McLachlan, N. W., 114, 298, 346, 385, 505 BOOK REVIEWS. Medlam, W. B., 524 Davies, B. IL, 489, 604 " Acoustics of Buildings." By A. H. Davis, D.Sc., Davis, A. H., 56 Page, W. I. G., 279, 326 and G. W. C. Kaye, O.B.E., MA., D.Sc., De Haas, A., 313 F.Inst.P., 623 H. B., 240, 290 Dent, 70, 510 Devereux, F. L., 173, 450, 481 " Radiophare," Broadcasting Map of Europe (A. C. Cossor, Ltd.), 264 de 557 Ridge, T. W., 810, 649 Donisthorp:, H. A., Robinson, E. Yeoman, 180 239, "Crystal Control of Transmitters" (Pamphlet). Editor, The, 1, 25, 55, 85, 113, 141, 167, 191, 215, Quartz Crystal Co., 516 273, 297, 321, 345, 371, 395, 423, 449, 475, 499, Sanderson, R. W. W., 48 523, 547, 573, 609, 633, 661 Sims, L. G. A., 60 Smith, H. F., 143, 322, 349, 396 " First Course in Nomography, A " (Useful Data Garton, C. G. and G. S. Lucas, 216 Smith -Rose, R. L., 476 Charts). By S. Brodetsky, 637 Smith -Rose, R. L., and E. L. Hatcher, 614 Hatcher, E. L., and R. L. Smith -Rose, 614 Sowerby, A. L. M., 86, 131, 162, 168, 274, 301, 412, " Physical Principles of Wireless, The." By J. A. Haynes, F. H., 2, 26, 331, 372, 427 424, 456, 491, 648, 617, 644 Ratcliffe, M.A., 420

Printed in Great Britain by The Cornwall Press Ltd., Paris Garden, London, S.E.X.

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www.americanradiohistory.com AND RADIO REVIEW (161h Year of Publication) 1

WEDNESDAY, JANUARY 2ND, 1929. VOL. XXIV. No. I.

question which yet remains unsettled in spite of the fact Editor: HUGH S. POCOCK. that it becomes year by year a factor of greater impor- Assistant Editor: F. H. HAYNES. tance to the listener whose interest in foreign reception Editorial Offices: 116 -117, FLEET STREET, LONDON, E.C.4 steadily increases. Editorial Telephone: City 9472 (5 lines). Advertising and Publishing Offices: For the B.B.C. DORSET HOUSE, TUDOR STREET, LONDON, E.C.4. Next, we may turn to our own Broadcasting Corpora- Telephone: City 2847 (x3 lines). Telegrams: Ethaworld, Fleet, London." tion and invite them not to halt and look back with pride COVENTRY : Hertford Street. Telegrams: "Cyclist, Coventry." Telephone: 5210 Coventry. on the accomplishments of the past but to face the future

BIRMINGHAM : Guildhall Buildings, Navigation Street. with that same pioneering spirit of enterprise which has Telegrams: "Autopress, Birmingham." Telephone: 2970 and 2971 Midland. built up the foundations of our broadcasting service so MANCHESTER : 260, Deansgate. Telegrams: "IlitTe. Manchester." Telephone: 8970 City (4 lines). surely, and let them never forget the prime object for GLASGOW: 101, St. Vincent Street, C.2. which the Corporation exists, however alluring might be Telegrams: "I1ife, Glasgow." Telephone: Central 4857. the picture of a jam factory as a profitable commercial PUBLISHED WEEKLY. Subscription Rates : Home, z7s. 4d. ; Canada, 175. 4d. enterprise. other countries abroad, 1gs. 6d. per annum. If it has been decided that the Regional Scheme is to Entered as , econd Class Matter at New York, N.Y. be the basis of our broadcasting distribution, then let that As rnany of the circuits and apparatus described in these pages are covered by patents, readers are advised, before making use of them, to satisfy themselves scheme be proceeded with without delay or hesitation. that they would not be infringing patents. Before we conclude our New Year resolutions for the British Broadcasting Corporation, let us remind them CONTENTS OF THIS ISSUE. that what others can do, and have already achieved, PAGE in the direction of short-wave world broadcasting, that EDITORIAL VIEWS ...... BUILDING A PICTURE RECEIVER. By F. H. HAYNES.. .. much, at least, we expect of them. WHO'S WHO IN THE ETHER. BY J. GODCHAUX ABIRAHAMS .. CURRENT TOPICS ...... 13 For the Manufacturers. PROGRAMMES FROM ABROAD...... 15 VALVES WE HAVE TESTED. Two NEW MARCONI AND OSRAM VALVES .. 19 To the manufacturers on whom we are all dependent BROADCAST BREVITIES ...... 21 for our wireless apparatus, let us commend as a New LETTERS TO THE EDITOR ...... 23 READERS PROBLEMS ...... 24 Year resolution that they should not ignore the hopes of the public that in 1929 the announcement of new products may coincide with the ability to supply to the NEW YEAR RESOLUTIONS. public by a more successful anticipation of public de- HE making of New Year resolutions is a practice mand. Next, let us invite the manufacturers to consider of questionable value, for so often such resolutions the question of standardisation, which is still in many are hastily framed and recklessly undertaken only branches of the industry a matter of vexation and dis- to be broken before many weeks or perhaps even many appointment. Let us have standards in sizes of such days of the New Year have passed. details as grid batteries, so that different makes may be We do not, therefore, propose on this occasion to make interchangeable ; a standard nomenclature for valves and New Year resolutions for ourselves, but instead to adopt standardisation in the methods adopted for the dis- the very much easier task of suggesting some New Year tribution of electrode connections in the screened -grid resolutions for the observance of others for the mutual valve. benefit of ourselves and our readers. Standardisation is called for in a host of other instances, and whilst the price of different makes of valves A Resolution for Geneva. is practically standardised according to type, yet we First, let us turn our attention to the broadcasting would remind the valve manufacturers that such stan- authorities of Europe, and especially to the -Geneva Com- dardisation need not be upset by a scale reduction of mittee, and for their consideration recommend a New prices of valves in 1929. Year resolution that 1929 shall see the elimination of all In conclusion, whilst wishing our readers all prosperity mutual interference between the broadcasting stations and happiness in the New Year, we also take this of Europe and the establishment of wavelengths and opportunity to invite them to offer to us their sugges- power on a basis of equity which shall give satisfaction tions to guide us in any direction in which they may in every country. We would also recommend to Geneva think the value of our service to them may be the consideration.of station identification signals, a vexed enhanced. A 53

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WfirnIlmo JANUARY grid, 1929.

BUILDING A

Making the Components.

By F. H. HAYNES. SINCE picture transmissions became part of the be followed out by a home constructor possessing the Daventry programme many enquiries , have been modest array of tools required for the construction of made for details of th.3 apparatus needed for the radio sets. To meet this new situation, therefore, cer- reception of the pictures. It has always been implied tain conditions must be fulfilled in contemplating the that whatever device may be required in radio recep- design. First, the components must be of simple de- tion or transmission that it is within the skill and facili- sign to suit the home model maker, and, secondly, they ties of everyone to construct the necessary apparatus. must be capable of being easily and cheaply manufac- So with the picture receiver, and it is taken for granted tured so that the parts can be readily purchased and that the making -up of such an instrument falls within assembled with the same ease as the making of a simple the scope of the kitchen table workshop. wireless set. To build a machine from raw materials which will receive the pictures in a reliable manner will prove an Finished Components to be Available. attractive undertaking for the model maker who pos- Regard for these two considerations has governed the sesses a small lathe and a few bench tools. It is out details of the designs which have been developed for of the question, however, to attempt a design that can inclusion in this article. The more elaborate units are dealt with here so that the model maker can proceed with their construe- tion ready for their inclusion in the complete design to be given later, while the manufacturer will be able to supply the made -up component parts almost as soon as the complete design appears. More than a year ago the writer gave a simple design for a picture receiver, and described its construction and operation.' That instrument, although taking the simplest possible form, is capable of receiving the pictures transmitted to -day, providing that the dimensions of the cylinder which carries the paper and the pitch of the thread which causes it to be traversed are brought into line with the standards that have now been set up. Whether or not it is true, the wireless amateur feels that his home -built

Schematic circuit diagram showing the action of the various components of a t " Practical Picture Receiver," August Fuitograph picture receiver. 24th, 1927. A i{

www.americanradiohistory.com JANUARY zfad, 1929. WhadMO 2 WorIlcál Building a Picture Receiver. - approached a cam (d) rotating with the spindle breaks receiver is better than one he might buy. This point the magnetic clutch circuit, and the trigger falling into of view deprecates any bid for simplicity which might a slot locks the action. Concurrent with the breaking render the instrument of his labours inferior to the com- of the clutch circuit contacts which normally short -cir- mercial article. Two good reasons necessitate that this cuit the relay are opened (a). A metal cam actuates design must use as its basis the Fultograph picture receiver. It is to receive from transmissions made with Fultograph apparatus, while a detailed examination of that machine reveals such perfection that any attempt at drastic modification for development on new lines is not likely to lead to the production of a better article' The Fultograph System. To avoid reiteration of the details of the Fultograph system the reader is referred to the description and circuits which have already appeared in this journal.' Briefly, the action of the various components is as follows : A trigger (f) engaging in a slot (g) arrests the rotation of spindle and cylinder once each revolu-

SOFT IRON i 4 2 6 B.A CH.HD.SCRS I/4" LONG. I11 X / 2 B.A.CI -l. HD. TAP6BA. SCQS. X 4" LONG. 516

ti1TI FOUR STANDARD 1000(.6 3OBBINS 6.BACLR_2,6 3 .A skx14LG. Itil 6B.A.SCRX3/S LONG, END BELL 4 PUNCHED FOR BEARING POINT COMPLETE WITH LOCK -NUT. 4 -ßi, /8 BRA55 TUBE 900*-s P21 NG . 6BA.C/SK. r V yc y.. BA.CL2 5/ 6 I

5C2..X . LONG . k 1 1 6.8.A / - EBONITE BUSH ON UNDERSIDE 8' 6BACHHD.SC2X3/4 Ï S LON 2,6 B.A CH. HD 5C25. 24o 6B.A SC R. X3/8 LONG, ENO BELL X 5/8" LONG. PUNCHED FOR BEARING POINT DRILLED FOR TIGHT FIT ON SPINDLE. CONTACT ,16

TAP _B 543 END TAPPED SBA F:`IZ AND SLOTTED J 2/z CONNECTION POINT. I 4 BONE OC EBONITE vi6 G. B.A.CL2. ` TI P ----I e44041441g"- 2,6 B.A (2D HD. 5CR5. jr;4 X l$, LONG n /-- TAP. 6.B A. SOFT 120N /S CONTACT (BLIND) PHOSHOR BRONZE

THE RELAY. This design is given as a basis for constructing a simple relay possessing ample sensitivity. Modifications can obviously be introduced to make use of any small parts one may have to hand. An extension on the magnet bracket shown in photograph affords an alternative support for a release spring. tion. To avoid imparting a shock to the driving this contact, and short-circuits the path whereby the mechanism and to ensure an immediate restoration of incoming signal is taken to the stylus and the cylin- rotation at constant speed, the drive is applied through der (b). It is in this position that a momentary break a magnetic clutch (h). As the position of stopping is occurs in the transmission pending the sending out of the synchronising dot. On receipt of the brief syn- The. Fultograph." First complete description, October chronising signal the relay is actuated, and, in turn, 24th, 1928. pulls back the trigger, thus setting the cylinder free. A 15

www.americanradiohistory.com 4 WFi'ghoo GIolitcl Building a Picture Receiver. - cool as the fire extinguished. The armature may need Back contacts (c) on the trigger provide for energising similar treatment. the clutch at this moment, but as soon as the cylinder The base plate on which the relay parts are assembled has moved off, this is taken charge of by the cam con- is turned from a brass blank or piece of pain. hard tacts (d). It is important that the synchronising signal brass sheet, and the step at the edge allows of the fitting of a cylindrical cover. A clock spindle is made a tight fit in the armature, and is mounted in a bracket between two hollow -ended screws. This bracket is made from a piece of uin. channelled brass. A small piece of brass tube inserted at its edge before filing down to size encloses a light coiled spring which is adjusted by a screw in the end of the spring. The contact blade is a piece of stiff bronze. Overall Test for Relay. Platinum contacts are to be recommended, and all the contacts needed for the machine can be made from tin. of No. 20 platinum wire. A further tin. No. 24 platinum wire will be required for the tip of the stylus. The stationary contact and stop are mounted in a bracket cut THE CLUTCH. The small ring in the centre engages on the pole face while the three pins impart the drive to the catch plate shown on the right. from lin. brass sheet. This bracket is actually a telegraph relay fitment and can shall continue and the trigger be held hard out and its be readily picked up second hand. A piece of rim contacts (c) closed until the clutch cam (d) has moved by tin. angle brass supports the magnet. clear. Further rotation causes a closing of the con- The four bobbins are of standard size and can be tacts (a) which are across the relay winding, and re- purchased ready wound to z,000 or 2,000 ohms apiece. moves the short circuit (b) between stylus and cylinder, It is as well to test the polarity of each bobbin before so that the incoming signal is now diverted to cause a assembling. They are connected in series with N and marking on the paper. Analysing the machine into its S ends adjoining each other following around the " U " component parts, we have the relay, the trigger, cylin- of the magnet. An error in connecting up is easily der and cams, spindle, magnetic clutch and pinions, the made and will render the relay insensitive. An 8,000 motor and baseplate, the carrier for the knife wheel ohm relay should pull up on 8 volts and with a 4,000 and stylus, and the radio components, such as milli - ohm winding the approximate equivalent test potential ammeter, input transformer and valve. with fewer turns and increased current is 6 volts. Trigger. As angle brass of suitable size is not avail- A Sensitive Relay Required. able for constructing the frame and to avoid the trouble Relay.- Sensitiveness of the relay is one of the limit- of making a small brass casting a piece of tin. soft ing factors of the range of picture reception. It should brass sheet (bending brass) was bent up to form a be as sensitive as is reasonably possible, and a good piece on which the parts might be arranged. The standard to specify is that it shall be actuated with a armature lever is shaped from a piece of hard brass good pressure at its contacts with a current of u mA. strip and great care is needed in setting it upon its when its resistance does not exceed 8,000 ohms. After bearing pin in order that it may be absolutely true and tests with both polarised and non -polarised types it was free from side play. It must be realised that there is apparent that a non- polarised relay gave the better re- an appreciable pull on its bearing pin at the moment sults and was easier to adjust. It is essential, how- that the catch -engages and stops the rotation. When ever, that the iron used for the magnet shall not retain the catch is just engaging the brass piece is vertical so appreciable magnetism. If it does, increased pressure that the face of the armature actually tilts towards the must necessarily be applied by the tensioning spring in order to restore the arma- SCREWED 25 THREADS PER cm. 3/ ture, and this will render 7mm DR. 12 DIA. DIA. the relay insensitive. The magnet used was actually cut from a piece of soft I-4---252 cast -iron, and was not 'I<3/4-` found to be satisfactory until it had been heated in a bright fire and allowed to Dimensions of spindle with traversing thread arranged to suit a standard magnetic clutch. A 16

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CONTACTS PILLAR TAPPED 6.BA. SPEING, No 24 SW.G. GERMAN SILVER. AND SLOTTED EBONITE SPACER /dDIA.xl 1/S'LoNG +'/ SCREWED IOB.A. 6 B.A.SCR. X SIB LONG. CURVE I3/6 RAD. AND FINISH TO FIT SLOT. SCREWED 6B.A 2.6B.A.CH. HD.SCRS Z I0.BAso: X 3/$ LONG. EBONITE BUSH 2,10 .A.C/SK.HD.SCR5 %Yá LONG. x 1/ß Lone.

2 HOLES 6B.ACL2 2HOLES DRILLED S/C/SK. 4 HOLES TAPPED 10 BA /4 419 FOR tO B A.SÇR.S. FOR TERMINAL 4HOLE5 TAP *B.A. POINTS. 3/4 STEEL PIN 16 S.W.G. TIGHT FIT IN ARMATURE 2,6BACH Sag HD SCRS. )( TAP 6B.A. 511 I ILONG B 6=^ 3/I6 DRILLED 9cc/sK.F02 - -i SCREWED 10 B.A. SC2S. 6 B.A. 3/a lyz HOLES 66A.CLR qB s 2,IO BA. C/SK.HD.SCL$ e 1S/g END TAPPED 66.A. X 3/16° LbNG 2 HOLES' a 32 3/IG' DIA. I 4 DIA. TAP IO B.A. PILLAR TAPPED 6.B.A. AND SLOTTED. 2 POLES 29/32 THUS. SOFT IRON L/4 DIA, 32 _ B.A. CH. HD.SÇR 6 B.A SCR.X5/B TAPPED X l/2" LONG. LONG 9.LOCI*NUT. 6B.A iA RIGHT THEO. SCREWED 6.8.A. PHOSPHOR. BRONZE 16 SPRING 24 S.W.G. S ° 4 DIA. Z EBONITE BOBBINS THUS THE TRIGGER. Here again, obvious modifications may be introduced providing that the tensioning spring, back stop, catch and contact are in the approximate relative positions shown. The arm carrying the armature must be free from side - play and robustly mounted.

. from bronze Steel is used for making the catch, and after being wire and carefully fitted to size it will need hardening. gives a. fairly strong pull on A Light Well Balanced Cylinder. the arm. A Cylinder and Cams. Lightness is the only aim in small brass making the cylinder, a fact which is, perhaps, not soldered - o n obvious from the drawings. A piece of brass tube of nipple pre - suitable size is readily obtainable, and should be vents the end examined for trueness. Circular blanks are soldered in of the spring for the end pieces, and metal is removed wherever from pulling through hole at the end of possible. It is finally trued up when mounted on a the brass upright. spingle, taking care not to reduce the wall thickness to, It is the top contact that limits the pull of the arma- an extent where it becomes springy. The cylinder should ture, and complete details of its construction can be be exactly 5 cms. in diameter, for an error in the gathered from the drawings. Platinum is not essential diameter will result in the length of the received picture for this contact and silver, gold -silver or German silver being slightly modified. In making the cams, small may be used. Suitable contacts can be removed from pieces of brass and bakelised sheet kin. in thickness are the blades of old breakjacks. Good insulation of the filed to shape and finally reduced to exact size in the magnet windings from the frame is essential and turned lathe after mounting. A iy

www.americanradiohistory.com ['MITI 6 JANUARY 2nd, 1929. WopIld Building a Picture Receiver. - winding has a resistance of 25 ohms, and this winding Spindle and Bracket. A skilled worker can make will give satisfactory performance also on 2 or 6 volt his own spindle, and no constructional comment need supplies. In this connection it may be pointed out that be made here, though a good deal of trouble may be the 4-volt trigger winding can be used with a 6 -volt saved by purchasing the finished article. battery. Its mounting brackets are cut from 2Ìn. face rough Two annular brass rings mounted on bakelised sheet angle iron, so that the centres may be accurately set on the reverse side of the clutch serve for picking up contact. The magnet runs free on the spindle while the catch plate is held with a grub screw. This clutch 10 HOLES 7/16" DIA. ON Sit RAD. AS SHOWN. CAMS ASSEMBLED together with fibre to brass worm pinions can be pur- AS SHOWN chased complete. A reduction of about loo to 55 is

4a A c.RUB Sc2 provided through the pinions. Fibre frictioning pins BRASS COLLAR ii6DIA are also fitted to the clutch so as to maintain rotation 6IXix LONG,, when the clutch cam lifts. The Motor. A good gramophone motor is selected for this purpose. Its spindle should run perfectly true and should be reasonably free from play in its top HOLE 3401A bearing. For securing the brass pinion an adaptor is necessary on the gramophone spindle and this should fit down on to the taper. The Carrier. Much latitude exists in constructing an 4!s" easy running carrier used to link the knife edge wheel secnoN SHOWING and stylus. It runs on a ASSEMBLY JF BEASS pair of " V " pulley wheels COLLAC' so as to offer a minimum of resistance. A frame has been assembled, using Bin. square brass tube and Constructive details of the light brass cylinder and contaçt cams. ¡in. square brass for the arms, though for manufacturing purposes a small brass or aluminium casting up at 5 cm. above the base plate. It is absolutely could, of course, be adopted. The angle of the necessary that adjustments of the end screws shall not knife edge wheel is such that it does not quite bed down rotate the -centre points. These centre holes are best into the bottom of the thread on the spindle. Its made by mounting the screws in a piece of brass which diameter is equal to that of the spindle, while the two has been accurately drilled and tapped in the lathe. centres used for its bearings are liberally spaced to Magnetic Clutch. Reference to an accompanying illus- prevent wobble. Should the knife edge wheel not run tration reveals the general principle of the clutch. It perfectly true, it may be left locked between its centres. consists of a short recessed iron cylinder and cover Firm brass pillars support a length of ¡in. silver steel on plate resembling very much the magnet of a moving which the carrier freely runs. Pieces of bakelite sheet coil loud speaker, though being very squat and having provide a support for the platinum- tipped stylus pin. a gap of about ¡in. This gap carries a cork inset, and In a further article, details of assembly and operation when the magnet is energised a floating ring is pulled will be given assuming the making or purchasing of down on to its face. On the back of the floating ring components more or less following this specification. are three pins which permanently engage in the catch Certain of the components are already available, and plate. A light spring keeps the ring in friction con- other sources of supply will no doubt arise in the mean- tact with the pole face. For a 4 -volt circuit the magnet time.

The easily constructed picture receiver previously described in this journal. A IH

www.americanradiohistory.com Vv JANUARY 2nd, 1929. p@Il@om 7

WHO'S W

.' i

.;}»i N,1 _1 i ia 1

A Guide to the Identification of Distant Transmissions. By I. GODCHAUX ABRAHAMS. " AM a mere novice in wireless, but have constructed receivers used for distant reception it may be taken that the three -valve receiver. Last night, at we have two tuned circuits each of which is tuned by 9.30 p.m., I heard some music, and later a ticking means of coils and variable condensers. If fixed coils noise like a clock. I do not know the wavelength, but my are used, covering a large portion of the band, i.e., say condensers pointed to 63 and 75. What station was from 2oo -600 metres and from 1,000 -2,000 metres, the that? " matter is considerably simplified ; the use of inter- To the listener who has handled his wireless set for changeable plug -in coils with their more restricted range some little time the question appears a hopeless one, and means slightly extra trouble, for whereas with the former it is true that it would be exceedingly difficult to give as we increase the capacity by means of the condensers it a satisfactory reply. Yet, at the time, the data we should get a regular sequence of higher readings in furnished comprised all the information the beginner degrees, plug -in coils would give us irregularly increased had gathered from the transmission heard. Later, with- readings, owing to the fact that the wavelengths covered out doubt, important details which had escaped him by them would overlap. As an example, a station would would thrust themselves upon his notice, and if his be tuned in on one coil at a high reading, and again, observations were logged while still fresh in his memory, the same station on the next higher coil at a low reading it would be an easy matter to solve his problem. of the condenser dial. Unless a transmitter is labelled by a clear announcement, such as the name of the city from which the speech Estimating Wavelength. or music is broadcast -and this is not necessarily an in- Bearing in mind that a higher reading on a condenser fallible proof in view of relays -for the purposes of (equivalent to an added capacity) indicates a longer wave- identification, means must be found to estimate as accu- length, we have in this a simple way of placing the rately as possible the wavelength on which it is picked " mystery " station in its approximate position in any up. table we care to draw up. Although some slight varia- Roughly speaking, three important factors are indis- tion may occur in the degrees of the aerial condenser pensable, namely, some correct idea of wavelength, an according to the length of aerial used, it will be found indication of the language heard, and some information that the readings on the condenser controlling the second- as to whether we are receiving the transmission from its ary tuned circuit will prove to be a permanent value for original source or through a relay station. We can esti- any given wavelength. mate the position of the transmitter in the wave -band in To estimate the wavelength of transmissions we have a rough- and -ready fashion by an easy method, for which three methods at our disposal : (i) a calibrated wave - but little explanation is required. What we want for meter, (2) a chart or graph to show the relationship be- so doing is a list of the broadcasting stations, in order of tween dial readings and wavelengths, and (3) a simple wavelengths, and a sheet of foolscap paper or a small table showing the condenser readings against already logbook in which to enter the settings of the condensers recorded known wavelengths. 'The first two methods as each transmission is tuned in. In most valve named will not be dealt with now. It suffices to state that

A Iq

www.americanradiohistory.com 8 Wfip.shoo JANUARY 2nd, r929. Worflccil Who's Who in the Ether. - with which I will deal later, you will gradually increase by the use of the meter it is possible to measure the Nvave- your records until the graph shows the majority of the length and thus assist considerably our identification of stations you have picked up and which you may again the transmitter. For the plotting of a graph (method 2) capture on a future occasion if you use the same settings. we require a sheet of paper ruled off into a number of large squares, each of which is subdivided into one Clues Revealing Identity. hundred smaller squares. On the left side of the sheet Personally, although this kind of chart has much to we mark off a scale from, say, o to zoo or 18o, accord-. recommend it, for my own work I prefer the simplest ing to the condenser dials used on the receiver, and on kind of log, namely, a mere record of the condenser the bottom of the sheet we record at the edge of each readings jotted down on a sheet of foolscap in order of large square numbers comprising the range of the coils wavelengths. Make a list of the principal stations work- used, i.e., say from 250 -550 or 600, in steps of fifty, ing on the band from 241 metres (Nuremberg) to, say, leaving the smaller squares to denote increases in fives. 58o metres (Laibach). If you wish to do so, you may I trust this is clear to you. All that we need now do, leave spaces for the smaller relays which no doubt you providing we have adopted square law condensers which will pick up at some time or other, and add to the list. will give us wavelengths, is to plot out on the graph the Divide the sheet into vertical columns thus : (i) Wave- position of well -known statiorfs length ; (2) name of station ; (3) which we have already identified. aerial condenser ; (4) secondary +t In every instance your local sta- circuit condenser, or, in the case tion will be one, and possibly of a " superhet.," aerial con Daventry 5GB another. With the denser and oscillator. As you knowledge of, say, the wave- record the stations identified so length of 2L0, if you live near you will find by looking at your London, and the readings of the log the approximate readings on aerial or secondary tuned circuit which you may expect to find the condenser -preferably the latter transmission you wish to tune in. -at which it is brought in, we can It may only be a rough -and -ready plot our first position on the guide, but it will give you suffi- graph. Merely make a dot at the cient data to narrow down the junction of a line taken from the search over, say, ten degrees of condenser reading on the left of the dial, as against wasting the sheet with that of another line time by swinging the condensers (vertical one) starting from the backwards and forwards in an actual known wavelength of the aimless and less systematic transmitter marked at the bottom manner. of the chart. Do the same with, Now as to the question of say, Daventry 5GB, and any identification. If all stations gave other stations you may pick up their call regularly before or and of which the wavelength and after each item broadcast, or condenser readings are known. adopted some simple identifica- You may now draw a line tion signal as The Wireless World through the dots plotted on the has often recommended, the graph, and if your r-. registration matter would be a simple one. was accurate, it should be a fairly Unfortunately for most of us, al- straight one. though some studios do so at vari- Now, to tune in to a trans- The steel lattice towers of the Stuttgart broad- ous intervals during the broad- mitter, of which again you know casting station. cast, others are more negligent, the wavelength but not the con- with the result that the listener denser readings. Simply look at the graph. Say you may " hang on " for quite a long period without re- want Stuttgart ; draw a line upwards from its wave- ceiving any clear clue as to the origin of the broadcast. length at the bottom of the chart, place a dot where it It is true that the constant reiteration of the name of the joins the line you have drawn through the logged city or town from which the transmission is made, stations ; all you need to do is to follow the horizontal although of help to more distant listeners, would prove line to the left until you read off the degrees of the wearisome to the nearer subscribers for whom the wire- condenser inscribed on that edge of the chart. If now less entertainment is primarily destined. In order to you turn the condenser of your receiver to that posi- avoid this repetition and to advertise their presence on tion, somewhere in that neighbourhood you should pick the air, many stations have adopted opening or interval up the transmitter's carrier wave. The matter is much signals, of which there happens to be a considerable simpler than it appears in print ; a graph can be plotted variety. Germany, I believe, was the first country to in a few minutes, and, providing you do not change the use a metronome between items broadcast, and this coil, and the stations maintain the same wavelengths, system has been copied by a large number of studios. you will . find the chart of considerable help. As you To -day, but for the fact that the " beats " vary greatly tune in to and identify other transmitters, a question per minute, the use of this instrument has somewhat A 20

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TANUARY 2nd. rn2n Wfirnhoo Wad. 9 Who's Who in the Ether. - the programme. In the same way Stuttgart will call defeated its object. In view of this drawback you will Achtung! Suedfunk, and by doing so ropes its i elay find that other methods have been devised by which Freiburg into its net, and the Bavarian transmi tters some of the transmitters possess highly distinctive (Munich, Augsburg, Nurnberg, and Kaiserslau tern) signals which can be recognised easily, and once heard are collectively referred to as Die Deutsche Stund e in cannot be forgotten. Of such we have bells, chimes, Bayern. As an afterthought, perhaps, a cons Hen- gongs, hooters, musical boxes, Morse signs, to mention tious announcer may now and again make it clear that but a few of them, and these, in some instances coupled you are in touch with Munich (Meun -shun) and N urn- with certain characteristics taking into consideration the berg (New- ren- bairg). approximate wavelength on which we judge the trans- Signals. mission to be, according to our graph or log, will Characteristic greatly assist identification. There are other examples I might cite, but these wil Before I take these different characteristics in detail, suffice. Alternately, as stated above, we may be given there is one point to which I should like to draw your the name of the station or city, but unless we I< attention. Primarily, it concerns those readers who its native name, it is difficult to recognise it undeir the possess receivers working with frame aerials. Their Tallinn (phonetic : Tar -leen) to us doess not directional properties can be of like Reval, nor Ljubl jana great assistance in determining (Looblee-arna) like Laibach ; it is the position of the transmitter in just as difficult, unless you respect to the listener. If, for know, to identify Posnan Poz- instance, in London, I happen name) as Posen, Coln (K euln) to pick up a transmission on, as Cologne. Moskva as Mos- say, Soo metres or so, and my cow, Wien (Veen) as Vie nna, aerial points east and west, it is Praha as Prague, Kaunas Kow- not difficult to realise that the nass) as Kovno, and Huizern, as broadcast is not reaching me by the D utch from the west, but from the announcer (Hoy -zen), and Continent of Europe. A little many others. However, the reflection (and examination of difficulties are not insurm ount- any wavelength list, if necessary) able, as you will find when you will prove that eastwards (within have heard the calls on on e or workable limits) there are no two occasions. Your ear will stations transmitting on or near become accustomed to the that wavelength, and my atten- strange sounds, and the more tion must be drawn to the oppo- stations you tune in the more site side of the compass. But quickly will these foreign n ames until you have checked your become familiar to you. frame aerial's directional pro- As a general rule you may perties on stations whose posi- take it that with but few e xcep- tions are known to you, do not tions the German studios pr eface forget that local causes may their call by the word Acl tung possibly upset the directive (phonetic : Ar- toong) ; it signi- effects completely. fies attention, or " by your Many of the difficulties in con- leave." Its parallel in Fr ench nection with the identification is Allo! of foreign transmitters arise I distinctly referred to Ger- from the fact that in the call, 'rhe Norag" equipment used for transmitting man studios, for although the either the name of the city or identification sounds and signals. stations broadca st in town is not given, or, if it is this language, they never use included, the native name is totally different to the this word. Now, since Vienna has been blessed IA a one by which we know it in the English language. In high -power transmitter, you will most certainly have the former case we find that some of the German heard his clear Allo! Wien! Curiously enough , the studios, when simultaneously broadcasting a pro- simple word Hallo can be pronounced by the foreeigner gramme from main and relay stations, use an abbre- many different ways. Take Radio Belgique ; listen viation which covers them all ; thus, when tuned in to the announcer's slow and deep toned Ah -low, or as to, say, Kiel or Hanover, you may pick up the words a contrast, Norway, where the Oslo microphone puts Hier Norag, which cannot possibly convey to the over a sharp Alloou Oslou. Then again, with the uninitiated foreigners -in this . instance, inhabitants of Polish stations, in particular Warsaw and Kattc witz, the British Isles -the information that the entertain- the word takes on a guttural sound, Rhar -low, us ually ment is common to Hamburg, Bremen, Hanover, followed by Polskie Radio, and the name of the city. Kiel', and Flensburg. But there it is ; we are not given The French stations are always recognisable by th e fact the names of the cities from which the " Norag " or that one " Hallo " is not deemed sufficient ; from them the North German Broadcasting Company transmits we hear a breezy but somewhat clipped twin Alk allo! A 2I

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4 ro Mp@hgg JANUARY 2nd, 1929. WoreIld Who's Who in the Ether. - by many transmitters, the beat and sound is variable, Now it must also be borne in mind that several Con- and by comparison it is possible to tell to which station tinental studios, for their calls and even announcements, you are tuned. have adopted a subsidiary language. Petit Parisien, Munich (Bavaria) and Rabat (Radio Maroc), although Paris, makes the matter easy for British listeners by working on this principle, appear to have adapted the giving out the programme items in both French and instrument in such a manner as to produce a distinctive English, but it would be a simple matter to mistake note. You cannot fail to recognise the Bavarian Radio- Sud -Ouest for a station situated in a neighbour- stations, as during the intervals you will pick up a ing country, for the Bordeaux " speaker " makes a sound as if a light hammer were hitting a double slat- point on every occasion of giving a Spanish translation something similar to the one used by Harlequin in the for the benefit of listeners in the Iberian Peninsula. old pantomime transformation scene, a double clop - Then again, Ljubljana (Laibach), Jugo-Slavia, when clop, clop -clop, sixty times per minute. The North going on the air or after any lengthy interval, draws African studio differs in this sense, that but one single attention to its presence by repeating its original Serbian stroke is heard, although it possesses a singularly call in German, French, English, and Italian. Berne, wooden and hollow sound ; the speed is the same. also, in view of its bi- lingual population, uses both With the German stations the beats vary little, German and French. namely, Frankfurt (192 to the minute), Zeesen and From the Polish stations on most evenings you will Berlin (210), and Koenigsberg and Breslau (240). Do hear a news bulletin in the French language, and in not forget that when the relays are connected to the particular from Kattowitz main station it is from the on some nights, thirty latter that the interval minutes or so of what is signal is heard. Now that termed the Letter Box, and Radio Toulouse has for- during which period the saken the metronome for station director, an accom- the stroke of a bell (one per plished linguist, verbally second) we only get the replies to his foreign corre- former instrument from spondents in French, Lyons, PTT (192 per Polish, German, English, minute), and from Radio and sundry other tongues. Vitus, Paris ; in. the latter Finally, on those dates on case the signal is not always which specific international given, but it is seldom you programmes are broadcast, will have to park on this or when, as is now custo- wavelength for more than a mary on the Continent, few minutes, as Vitus is a concerts are common to private transmitter owned three or four cities of dif- by a commercial firm, and ferent countries, announce- the call is carefully put out ments are invariably made at the end of every item. from the original studio in If we turn to Vienna we the languages of the notice immediately that the countries to which .the The Studio at the Frankfurt Station. metronome possesses a very broadcasts are destined, or, fast beat -in fact, it ticks alternately, fed by land line where this method is used. 264 times to the minute. The -Austrian station uses it If - I have dilated at some length on this question it consistently for every interval lasting more than five is merely with the object of warning the listener against minutes. taking for granted, when he has tuned in to a foreign With the German and Austrian stations on those days station, that its identity may be absolutely confirmed on which the relay transmitters give out their own pro - by the language heard. In most cases this will be a gammes, the signal used is either a single letter or a helping factor, in conjunction with other characteristics combination of two or more Morse symbols. As an which I will now detail, but in view of the fact that example, although tuned in to Hamburg, you may be others than the native language may be used, this pecu- receiving a programme from Kiel or another station of liarity alone would not in itself constitute a definite the Norag group. The relays identify themselves by confirmation. their initials : Bremen (BMN : - ... - - - ) ; Hanover (HR : . . . . - .) ; Kiel (KL : - . - . - . .), Use of the Metronome. and Flensburg, the latest addition to the letter F ( . . - .). I referred previously to the metronome, an instrument Hamburg, as a main transmitter, is the only German widely adopted by stations as an interval signal. I studio retaining a Morse çall, namely, HA ( . . - ). presume that by now almost every wireless listener must A similar method is customary with Graz and Klagen- be familiar with it, even if in his childhood days he had furt (Austria), but both appear to send out the letter - not heard its monotonous tick -tock, as he reluctantly K (. -.) . practised his show piece on the pianoforte. Fortun- The only other foreign transmitter of importance ately, as I have already stated, notwithstanding its use which has adopted this method, but only as an opening A 22

www.americanradiohistory.com JANUARY 2nd, 1929. Wilpasoo ii Wo wild Who's Who in the Ether - dance nights you may notice that the orchestra fades signal to its transmissions, is Warsaw (Poland), from out at ii p.m. G.M.T., when you are switched over which studio prior to the preliminary call by the to the Town Hall (Raadhustornet) for a time signal and announcer, you will hear the letter W ( . - - ) repeated chimes from its belfry. If all bells or gongs were struck several times. in the same manner or possessed a similar tone, we Until about two years ago, if we heard the voice of should be more perplexed than ever. Fortunately, this a lady announcer we were safe in assuming that it is not the case, as it has been possible to play varia- emanated from either an Italian or a Spanish station ; tions on them. to -day, on the Continent, the feminine speaker in many Should you reach out to Bratislava notice the sounds, studios has ousted mere man from that honourable call- viz., four bells answering to the notes FACC, or Koenigs- ing. From all Italian and Polish studios you will hear berg, two notes forming a perfect fourth (A flat and D a female voice, also on most occasions from Moscow, flat), or again, Stuttgart, with its flute -like tones Leningrad, and Berne, and periodically during the even- C, D, G, repeated until the studio transmits the next ing from Kiel, Hanover, Dresden, Frankfurt, Cassel, part of the programme. Nurnberg, and Bratislava. To the credit of the ladies, Then again the little Paris station of Radio Vitus, to however, it must be said that they are more conscien- which I have previously referred, should be identified tious in putting out the call of the station than their by its two bells (F sharp and D sharp), struck rapidly male colleagues, and will not leave you so long in sus- between items. Cracow, at intervals, gives you a fair pense once you have attuned your receiver to the imitation of a troïka (three- horsed sleigh) with its sledge transmitter's wavelength. bells, all sounds which, to Apart from metronomes my mind, once heard and and Morse signs, we find a logged definitely label a variety of gongs, bells, and station. other signals used to dis- You are all familiar with tinguish a station. All the old tuning note, which, studios in turn have given until some months ago, their engineers the task of characterised the B.B.C. devising some specific broadcasts ; you will find a means which will give the similar opening signal at station an individuality of Brussels, Cork, Dublin, its own, and as a result of Rome, Milan, and Naples, experiments many methods although in each individual have been created to obtain case the note differs. In a characteristic opening or like manner Munich uses a interval signals. hooter or siren (deep G) to No doubt at some time or announce its arrival on the other you will have cap- air ; it is immediately fol- tured a broadcast from lowed by the call (Hier Ljubljana -a fairly recent Deutsche Stunde in Bayern) newcomer to the ether -and previously mentioned. Of you will have picked up The announcers' sound -proof room at Budapest. late Copenhagen appears to the call of the cuckoo, a have adopted the same sound so familiar that you could not have mistaken it. method, which is distinctly helpful for identification. In the same way the short nine -chord tune repeatedly Admittedly there are, I am sorry to say, some stations played by Budapest as a stand -by signal, would be which neither give a frequent call nor possess any parti- correctly logged by you as originating from a toy cular peculiarity by which they can be easily recog- musical box. But, unfortunately, the Ljubljana cuckoo nised, and in such cases identification can only be estab- has a competitor on the air ; a brother or sister- at lished by ascertaining the position the transmitter Wilnc ; it is in such cases where similar sounds are occupies in the waveband, and noting in which heard that it is essential you should know to what linguistic family the words used by the announcer could approximate wavelength you are tuned. In this in- be placed. stance the difference is so great that you could not possibly take one for the other. How to Narrow the Search Within Definite Limits. Another characteristic signal has also been improvised From experience, based on the solving of many by Cologne, which prefaces its main transmission by a thousands of problems sent up to me, I find that most carillon of bells from the studio, and not, as might well listeners are capable of stating whether the language be thought, by the sound, from its famous cathedral. heard is of Latin, Teutonic, or Slavonic origin. The Bear in mind that you will hear these bells through point is, that although the enquirer might not distin- Langenberg or through any other transmitter of the guish between German, Dutch, or the Scandinavian Rhineland circuit. dialects, such an indication would narrow the search Gongs and bells have found favour with many down to. a more limited number of transmitters, and stations ; Copenhagen (and Kalundborg) open and close with the knowledge that the broadcast was made on the transmission with three resounding " pongs "; on an approximate wavelength of, say, 28o to 32o metres, A 23

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12 MEeggoo JANUARY 2nd, 1929. WOpIlcI Who's Who in the Ether. - exceptions to the rule, for some cities, in particular the by consulting the programmes or a list of stations in French, have substituted for the Marseillaise a sequence hymn, it should be possible to identify the trans- a folk song, or a patriotic melody associated with the mission without much district. trouble. In those instances, Finally, allow me however, to lay in which definite considerable stress on the proof is desired, and where adoption of a log, as sug- a record of condenser read- gested in the first part of this ings has been made, the best article ; its benefits are cumu- plan is to tune in to that lative. In the particular early stages wavelength at a you may spend some little later date for one special time in setting down records item in the week -end proof your captures, but as grammes these published in The grow, so you will find Wireless World, and which " landmarks " helpfully is to be expected from that dotted along the entire wave- station. In such an event band covered, thus as time choice could be made of an goes on daily narrowing the item such as an operatic limits within which the un- performance, a language known transmitters are to be course, or special musical placed. For the identifica- pieces, of which details are tion of stations all that is given in the station's list of needed is a careful record, entertainments, any of some patience, a modicum which of would furnish the Frankfurt's aerial and station building. common sense, and a reten- proof required. tive memory in regard to Although many transmitters close their evening pro- the peculiarities of the numerous broadcast transmissions gramme by playing their National Anthem, there are heard.

Short -wave Notes. The 10 -metre Waveband. F 8BP, operated by the " Journal des A correspondent in Gloucester com- 8 " at Rugies, Eure, France, broadcasts TRANSMITTERS' NOTES ments on the scarcity of British daily on metres signals 47 between 1330 and 1500 received on the 10 -metre waveband, stat- G.M.T., having abandoned its evening ing that though he transmission. issues supplements giving additional can receive many names ascertained since the publication of American stations at good strength, the XC51 a short -wave station of the the Annual only British amateurs he has Mexican War Department, and corrections where neces- yet been transmits sary. There is no official able to hear are G 20D and G 2KF. general sports news in English and list published of British amateur stations, as the records 0000 Spanish daily on 42 metres at 6 a.m. kept by the G.P.O. are regarded as New Call -signs and Stations Identified. G.M.T. ; - the news is supplied by the strictly confidential. G 5GR L. W. Trens News Service, Mexico City. The " Annual " may Gardner, " Gaydon," 40, Medina Rd., be obtained from the R.S.G.B., 53, Vic- Coventry. of address.) 0000 G MIL I. E. Hill, High toria Street, S.W.1, for 4s. post free. St., Upton -on- Severn, Russian Amateurs. Worcestershire. Secondly, the Citizens' Radio Amateur G MK (ex 2BGS), E. J. Laker, 4, Alford Rd., A correspondent asks if we can give Call Book, published semi -annually (in Cranleigh, Surrey' him any information regarding amateur the spring and autumn) by tha Citizens' G BRR (ex 2BGT), R. A. Rowden, 15, Pennsylvania call -signs Rd., Exeter. in Russia. We understand Radio Service Bureau, 508, South Dear- 2AJO Coventry Transmitters' Association, Hon. that the old call -signs are now being re- born Street, Chicago, U.S.A. This list Sec., L. W. Gardner (G 5GR), 40, Medina I placed by others, consisting of a figure includes Rd., Coventry. the U.S.A. stations as well as EI IG G. Manni, Pr. Umberto 205, Ronie. to indicate the district followed by two those in Great Britain and other coun- or three letters, but up to the time of tries of the world. We are indebted to Mr. Louis Era If we may draw a (EB 4BC) for the Writing have not received a revised list comparison between the two publications following :- of Russian QRAs. We shall welcome it will probably be EB 4EA Dirickx, 88, rue du Pavillon, Antwerp. found that the EB 4FE T. Van Hool, 119, rue Plankenberg, Deurue- any authoritative information on this R.S.G.B. Annual is more reliable as Nord, Antwerp. subject. regards European stations, while EB 4GIC Th. Nissen, 97, rue d' Orange, Antwerp. 0000 the EB 4HC S. Van Wouwer, Citizens' Call Book is more up -to -date de 228, Ave. Van Haute, Amateur Call= Signs. Deurue- Antwerp. with those on the other side of the EB 4HT J. Deciereq, 31, Avenue A. Goemaere, We are often asked by readers where Atlantic, as might reasonably be expected. Antwerp. EB 411V Respeu, 15, Plaine they can obtain complete lists of amateur We understand that next year an amal- de Malines, Antwerp. stations of EB 4IA L. Perlaux, 23, rue d'Orange, Antwerp. the world, with their call - gamation of these two lists is contem- EB 4JJ J. Joulet, 6, rue des Carmes, Liege. signs and addresses, so, risking the plated, and the EB 41X J. De Saegher, 5, rue Raikem, Liege. joint publication will EB 4LA F. Le Maire, charge of " vain repetition," we would probably be regarded as the 8, Vieille rue de Bruxelles, inform them amateur's Malines. of the three best known and, " Berne List." The price of the EB 4L0 P. Castaing, 42, Grand Place, Courtrai. as far as we know, the only publications Citizens' Amateur Call Book ER 5AF S /Lt. C. Bratescu, 45, rue St. Elefterie, of this kind. is 85 cents. Bucharest, Roumania. Finally, there is the official list of ET 1F W. Hinentalis, Aukst Karin Kursai, Kaunas, First, the R.S.G.B. Annual and Log Amateur Radio Stations of the United Lithuania. Book XEII for 1928. This contains all the States, corrected to June 30th of each 87RA Radio Wagon Merman Station, Leningrad, known amateur stations in the Russia. world, year, and obtainable from the Superinten- EA BL W. Blaschek, 29, Balmgasse, Klosterneuburg, with the exception of those in the United dent of Documents, Government Printing Austria. States. From time to time the R.S.G.B. Office, EA CM C. Martin, 8, Nussdorferstrasse, Vienna IX, Washington, D.C., for 25 cents. Austria. A 24

www.americanradiohistory.com JANUARY 2nd, 1929. VrArnhoo 'Vcre Il4 :3

il UFffiENT ------x ..., Iillll Ípll!ÍI ÍIih;P

Events of the Week in Brief Review.

HEARTILY RECIPROCATED I listeners at their electricitX works, as a LET'S CALL In this our first issue of 1929 IT A DAY. we take result of a complaint by the Electric NVEAF, the opportunity to thank all those readers New York, has just announced Light Committee that the practice a new schedule. Broadcasting of The TV reless TVorld who have so resulted begins at kindly in members of the public " wan- 6.45 a.m. and continues without inter- sent New Year greetings and dering all over the cheery wishes for the place." When it was mission till midnight. continued pros- asked whether 'the Council would provide 0000 perity of " W.W." charging 0000 facilities in listeners' homes TRANSATLANTIC TELEPHONE the electrical engineer said " No." DEVELOPMENTS. ITALY TO TRY SHORT WAVES. 0000 In accordance with plans On October 28th, 1929, the date on BRISTOL LISTENERS' for the de- which CLUB. velopment of the Transatlantic telephone the Italian Government plans to The Bristol Listeners' Club now num- open a new high service, new equipment will shortly be -power broadcasting bers over 300 members. The object of introduced station at Rome, using 50 the at the Rugby transmitting ' kilowatts, it club is to give its members special station and at is hoped that a short -wave station will facilities for visiting the Post Office receiving broadcasting sta- stations at Cupar (Fife) and Wroughton also be ready to relay the transmissions tions and other places of wireless interest. to America and the Italian (Wilts). colonies. Mutual help in the operation of sets is Two transmitters o000 another of and receivers are the club's activities. already engaged in the AERIAL FATALITY. service and a The danger of erecting aerials in the vicinity of electric power wires was again illustrated on Wednesday, December 19th, when Oswald Morris, a collier, of Tonteg, Pontypridd, and his wife were both killed when their wireless aerial collapsed. In falling the wire carne in contact with an electric light cable, and Morris, in attempting to raise it, received a fatal shock. His wife, who ran to his aid, was also killed instantaneously. 00 0 0 LANCASHIRE IS ROUSED. Lancastrians are showing an unwilling- ness to accept the statement of a P.O. official, made recently at the Bolton Police Court that there are more unauthorised transmitting stations in South Lancashire than in all the rest of England put together. When the question was raised last week at the General Post Office, an official said that the statement was based on the number of prosecutions. " We can offer no explanation," he said, " and of course it does not of necessity prove that South Lancashire people are the worst offenders ; but most of the offenders who are tracked down are in the Lancashire area." It is believed that Lancastrians are considering their next move towards clearing the county conscience. 0000 MEXBOROUGH COUNCIL SAYS NO." The Mexborough (Yorks) M.P.S AND Urban Dis- IHE MICROPHONE.-Conservathe Members of Parliament trict Council has decided to discontinue attended a demonstration of Marconiphone recently the General Election loud speakers at Wembley in preparation for charging the accumulators of wireless campaign. The photograph shows a member at the microphone testing the capabilities of four loud A 25 speakers.

www.americanradiohistory.com Wanllsm JANUARY 2nd, 1929. 1¢ Wodd. being con- wireless trade broadcasting companies third is expected to be in operation by ment were installed, the output upward tendency nected to a Senior Amplifier. The first and listeners for a period of five years July. If the present dating from November, 1927. of the service is con - four outputs of the latter were fed to in the popularity To carry out this arrangement the com- tinned, a fourth circuit may be added other Senior amplifiers, multiple wiring . pany has made heavy sacrifices, including before the end of the present year. being used which allowed of a common 0000 feed. In practice is was found that only an estimated sum of £62,500 on listeners' one -third of the maximum power was licences and a similar amount on valve GERMANY 'PHONES THE ARGENTINE. necessary to give ample volume to accom- royalties. Iu consideration for this the The wireless telephone service between pany the procession of singers. The bat- company will receive from the Govern- Berlin and Buenos Aires, which was teries supplied 2,000 volts, and the total ment a payment of 3d. per month, or an opened on December 10th, has now been current consumption was 22 amperes. average of 3s. per annum, in respect of extended to all German cities. Through The entire installation functioned per- every receiving licence issued. On a a regrettable inadvertence, it was stated fectly and was instrumental in conveying basis of 250,000 licences, the amount rein our issue of December 19th that the the sounds of the ceremony to a crowd ceived by the company under the service employed the Transatlantic tele- of 150,000. amended agreement will be £37,500 or phone system through Rugby. This is, 0000 £88,000 less than was originally claimed. of course, inaccurate; the service is a The company states that it has been indirect one .between Buenos Aires and EARTHQUAKE REPORTS BY WIRELESS. duced to make these sacrifices by a desire Nauen, which operates on 14.83 metres. At the request of the Meteorological to foster the popularity of -wireless. The first experiments were conducted Office, London, an arrangement came 0000 through the British stations. into force on January 1st, whereby NEW MARCONI APPOINTMENT. c000 seismological reports are transmitted Mr. Frederick Sandland Hayburn has regularly from Arlington, New York, and deputy OBITUARY. is been appointed a director with the meteorological message which managing director of the Marconi Inter- We regret to learn of the sudden death, sent out at 4h. 0m, G.M.T. The service which occurred on December 20th, of national Marine Communication Co., Ltd. Mr. Martin Hawke, managing director Mr. Rayburn, who has been associated of the Carborundum Co., Ltd. Al- with the company for over 24 years, is though he had been ill for some time, FORTHCOMING EVENTS. vice -president of the Comité International was formed re- Mr. Hawke appeared to be recovering, WEDNESDAY, JANUARY 2nd. Radiomaritime, which was at business on the day before Institution of Electrical Engineers, Wire- cently to co- ordinate the services of and less Section.-At 6 p.m. (Light Refresh- his death. ments at 5.30.) Lecture: The Design of marine wireless companies throughout the Transmitting Aerials for Broadcasting world. 0000 Stations," by Messrs. P. P. Eckeratey, 0000 MIND. T. L. Eckeratey, B.A., B.Sc., and H. L. WIRELESS AND THE CHINESE Kirke. LECTURES ON LOAN. A decrease in the characteristic hos- Tottenham Wireless Society. -At 8 p.m. At 10, Bruce Grove. Business Meeting, A short lecture on screen grid valves, tility of China to the introduction of followed by an evening with the Society's illustrated with eighteen lantern slides, wireless apparatus is referred to in an apparatus. and commerce THURSDAY, JANUARY 3rd. has been prepared by the Marconiphone account of Chinese life (Birmingham). the Paro- Tottenham Court Fox, commercial Slade Radio -At Co., Ltd., 210 -212, given by Mr. H. H. chial Hall, Broomfield Road, Erdington. Road, London, W.1, for loan to radio Counsellor at the British Legation, Talk' on Transmitting, by Mr. C. H. of Young. societies. We understand that the cam - Peking, issued -by the Department Ilford and District Radio Society.--In- a second lecture on the Trade. formal Meeting. pany is preparing Overseas Stretford and District Radio Society. -At subject of drawing power from A.C. Mr. Fox writes : " The somewhat 8 p.m. At 6a, Derbyshire Lane. mysterious objection which the Chinese " Chronicle " Receivers, by " Radidea." mains. 0000 have hitherto shown to the MONDAY, JANUARY 7th. Government Newcastle -upon -Tyne Radio Society. -At PORTABLE RADIO COMPASS. import of radio apparatus for broadcast- 7.30 p.m. At 11, Saville Row. Lec- ing purposes -until quite recently radio ture: Recent Developments in Broad- A new direct- reading wireless compass cast Receivers," by Mr. F. Youle, of the has produced equipment was officially classed as Marconiphone Co., Ltd. for use on small ships been munitions of war -is gradually dis- Hackney Radio and Physical Society. At by the Kolster Radio Corporation of New 8 p.m. At the Electricity Showrooms, is only appearing, and there are signs that the Lower Clayton Road, E.5. Annual York. The complete instrument existing restrictions on the import of General Meeting and Election of Officers. 31ft. in height and can be accommodated receiving sets, etc., will shortly be on an ordinary table. removed." 0000 In the matter of wireless telegraphy is supplied by the United States Coast RADIO WAR IN U.S. considerable progress can already be and Geodetic Survey in co-operation with The first battle in the war which has reported. the United States Weather Bureau and been threatening the American radio in- 0000 the Navy. dustry for some time has been won by A PUBLIC ADDRESS TRIUMPH. The meteorological message from " big business," as represented by the is re- broadcast from the Eiffel Corporation, Probably the largest task which a public America General Electric, Radio ever been called upon Tower at 6h. 20m. G M.T., and the American Telephone and Telegraph, the address system has information will be in- carry out was on the occasion of the seismological Western Electric, the Westinghouse to cluded in the re- issue. The international Electric, the International Radio Tele- Congress in . Sydney last Eucharistic code will be used for this Fruit and Wire- autumn. The major part of the work, or Strasbourg graph and the United (Austra- service. Details regarding the code, less Specialities Apparatus Company. which was entrusted to Amplion by consisted of supplying music wavelengths, etc., will be supplied the Their opponents are the Radio Protec- lasia), Ltd., Superintendent, Kew Observatory, Rich- representing indepen- a central source to a long procession tive Association, from mond, Surrey, on request. claim that the covering a route through the city a mile dent concerns, which in length. It was de- 0000 firms mentioned are monopolising the and three- quarters radio equip- sirable that the procession, in connection NO WIRELESS ROYALTIES IN manufacture and sale of of the Host, should en- AUSTRALIA. ment. with the carrying Commission has gage in choral singing. Synchronisation Doubts and difficulties in Australia The Federal Trade therefore 60 power over patent rights have been set at rest dismissed the complaint, deciding that was necessary, and prosecute. loud -speakers were employed in four by an agreement which has now been it is without jurisdiction to points along the reached between the Commonwealth It is reported that the Radio Protective hanks of 15 at vantage the attack by route. Government and Amalgamated Wireless Association will resume the accompaniment (Australasia), Ltd. It has been agreed pressing the Department of Justice to The band supplying " into was situated in the Domain. Here a that the Company's patent rights shall bring the Radio Monopoly microphone and Amplion Minor equip- be made available free of charge to all Court. A 26

www.americanradiohistory.com JANUARY 2nd, 1929. NiApCO WnIl( z5

,(,R FROM ABROAD

BARCELONA (Radio Barcelona), Call EA J1 (344.8 I'1111 : (ichubart), bp tine metres) ; 1.5 kW. -5.30, Sextet : - Station Ore.hes:ra, ìütty Selections Fox Fagan (Soprano), Trot, Smoke (D:u-ward) ; Tango, Qué triste es soñar and J. C. Browner (Bass). 10.30, News, Weather Report (Mas) ; One -Step, J'aime pas ça (Raspini). 6.0. and Close Down. International Market Prices and Exchange Quotations. FRANKFURT (428.6 metres) 4 kW. 8.10, Concert by the Station Sextet : Paso- doble, -2,5, Programme for Children. 4.35, Orchestral Concert Nacional (Ribalta) ; Selection from Aida (Verdi) ; from the Works of Karl Goldmark ; in Waltz, Waltz me (Holden) ; Idilio campestre (Valls) ; the Interval : Announcements. Selection from La viejecita (Caballero). 8.30, Ele- 5.10, Reading from a Novel by O. W. Studtmann. mentary French Lesson by Prof. Martin. 5.30, The Letter Box. 5.45, Esperanto Lesson 9.0, Chimes W. Wischhoff. by from the Cathedral, followed by Weather Report. 8.15, Pfarrer Taester, Talk : Goethe's SATURDAY, JANUARY 5th. " Faust." 6.45, Henriette 9.5, Exchange Quotations, News, Announcements and Fürth Talle : Humanity. 7.15, Programme relayed from Market Prices. 910, Concert by the Station Orchestra : Stuttgart, followed by Military March, La Vosgienne (Jacques-Dalcroze- Dance Music relayed from Voxhaus. Mouton) ; Habanera, La ultima lágrima (Cotó) ; All Times are reduced to Greenwich Selection from La tempestad (Chapi) ; Fox -Trot Tell HAMBURG, Morse) me you're soon- (Davis and Burke -Haring). Erl- Mean Time and are p.m. except 4 .. -.15 a.m., News. Programme of könig (Schubert- Salabert) ; Hungarian Dance No. 7 Gramophone Records. 11.10 a.m., Weather Report. (Brahms -Berce). 10.0, Programme relayed from where otherwise stated. u.15 a.m., Exchange Quotations. 11.30 a.m., Concert from Madrid, EAJ7. relayed Hanover (297 metres) ; in the Interval at 11.56 a.m., Time Signal. 12.10, News. 1.40, Exchange BERGEN (370.4 metres) ; 1.5 kW.--5.30, Programme Quotations. 2.30, Review of Books. 3.0, Illustrated Music for Children. 8.0, Programme for Girls. 7.0, Orches- skaja -Fantasia on Two Russian Folk -songs (Glinka) ; Talk by Dr. With. Heinitz. 3.30, Concert: tral Concert. 7.30, Saxophone Recital by Erne Selection from Der Tribut von Zamora (Gounod- Suite in Old Style, Op. 84, for Flute and Piano (Kronke); Reti. 7.50, Topical Talk. 8.0, Recitation by Karl Schreiner) ; Overture to Le Roi d'Ys (Lalo). 5.0, Suite, Op. 1, for Piano (D'Albert) ; Suite, Op. 16, for Bergmann. 8.30, Concert by " The Young Men's Film Review, 5.25, Talk in Esperanto by Hans Flute and Piano (Lilge) ; Gavotte for Piano (Philipp) ; Association " Orchestra,conducted by Mr. Gehring. Plehn. 5.35, Agricultural Talk by Herr Scheibe. Suite in D Minor, Op. 87, for Piano (Nieman) 9.0, Weather Report, News and Time Signal.. 9.15, 8.20, Shorthand Lesson. 5.50, Herr H. v. Wedderkop, Gigue for Flute and Piano (Hue). 4.30, Request Dance Music. Close Down. Illustrated Talk : Programme. Dr. 11.0 (approx.), New French Literature. 7.15, 5.30, Frieda Wunderlich, Talk : The " Protection of With the Microphone through Breslau." 7.40, Workers. 6.0, Talk : The Wanderings BERLIN (Königswusterhausen) (1,649 metres), 40 kW. Request Programme by the Station Orchestra. 9.0, of My Farthing-Review of the Hamburg Savings -12.45, Photctelegraphy Transmission. 1.30, Pro - News. 9.30, Dance Music by the Station Dance Bank of 1827. 6.55, Weather Report. 7.0, Relay of gramme for Children. 2.0, Herr Graef, Talk : The Orchestra. ILO (approx.), Close Down. the Programme of the Wireless Ball from the Curiohaus; Technique of Speech. 2.30, Weather Report and Fackeltanz (Meyerbeer) Mondnacht auf der Alster Exchange Quotations. 2.40, Dr. Elly Heuss -Knapp : BRIINN (441.2 metres) 2.5 kW. -3.30, Programme (Fetrás) ; Fantasia on A Midsummer Night's Dream Talk for Women, The Art of Telling Stories. 8.0, for Children. 3.30, Talk. 3.45, Selections from the (Mendelssohn) ; Barcarolle (Offenbach) ; A Night in News Venice, from the Educational Periodicals. 3.30, Pro- Works of Suk. Barcarolle ; Ballade ; A bouquet in Overture (Strauss) ; Festival Polonaise gramme relayed from Hamburg. ; (Svendsen) ; 4.30, Herr Tejessy, the band My Mother. 4.15, Talk : Education in Gramophone Selection ; Programme Talk : The Police Force. Dr. F. M. Feldhaus, Slovakia from the Tanagra Theatre ; 5.0, under the Hungarian Rule. 4.80, Music in the Intervals : News, : Sports Talk Instrumentss of War in Ancient and Modern Talk. 4.45, German Programme ; News and Popular Notes and Programme Announcements. Times. 5.30, Elementary Spanish Lesson. 5.55, Alf Songs. 5.15, Weekly Report for Journalists, by 10.50, North Sea and Baltic Weather Report. 11.0, Due, Illustrated Talk : Norwegian Folk- Songs. 7.0, Dr. C. Jerabek. 6.0, Concert of Dance Selections. A Polonaise through Ether!" Country Programme : The Peace and Comfort of the 6.45, Prof: Dr. Traub, Talk : The Czecho -Slovakians Provincial Town ; Musical Selections and Readings by before the March Revolution in 1848. 7.0, Popular HILVERSUM (1,071 Herr Fried Riding, followed by Relay from Voxhaus. Programme. metres) ; 5 kW, -9.40 a.m., 8.0 Concert : Overture to Nabucco Time Signal. 9.42 a.m., Daily Service. U.40 (Verdi) ; Ballet, a.m., The Two Pierrots (Drigo) Semiramis Police Announcements. 11.55 a.m., Concert of Trio (Rossini) ; La Gioconda BERLIN (Voxhaus) (484 metres) ; 4 kW. --9.10 a.m., (Ponchielli) ; Ernani (Verdi) ; Music. L40, Orchestral Concert under the Direction Market Prices. 9.15 a.m., Weather Report, News and Fantasia on Bellini's Works ( Urbach). 9.0, Pro- of Mr. Max Tak, from the TuschinskiTheatre, Amster- Time Signal. 10.0 a.m., Programme of Gramophone gramme relayed from Prague. 9.25, Relay of Tzigane dam. 3.40, Italian Lesson by Mr. Giovanni Rizzini. Records. 10.30 a.m., Exchange Quotations. 11.55 Music from Bratislava (300 metres). 4.40, French Lesson by Mr. R. Lafont. 5.40, Concert a.m., Time Signal. 12.30, Weather Report and News. of Trio Music. 6.25, German Lesson by Mr. Edgar 1.0, Programme of Gramophone Records. BRUSSELS (508.5 metres) ; 1.5 2.0, Ex- kW. -5.0, Dance Grün. 7.25, Police Announcements. 7.40, Programme - change Quotations, Agricultural Report Music from the St. Sauveur and Time Palais de Danse. 8.0, arranged by the Workers' Radio Society : Concert and Signal. 2.30, (less Talk by Herr E. Nebermann. Elementary English Lesson. 6.25, Intermediate Talk. 11.15, Close Down. 3.0, Dr. Paul Frank, Talk : Medical Hygiene. 3.30, English Lesson. 8.45, Pianoforte Selections. 7.0, Columbia Recitations by Albert Reinicke. 4.0, Orchestral Dance Records. 7.30, " Radio Chronique." HUTZEN (340.9 metres) 4 kW.-Transmits on 1,852 : Concert ; Concert Comedy Overture (K<'ler -Béla) ; Norwegian 8.15, In the Interval, Topical Talk. 10.15, metres from 5.4o p.m.- 12.10, Concert of Trio Music. ; News. Bridal Procession (Grieg) Andante appassionato 10.30 (approx.), Close Down.. 2.40, Programme for Children. 5.10, Concert of Gramo- (Ralf) (Scars ,la) ; Helvetia Valse joyeuse Pro - phone Selections. 6.10, Talk by Mr. Schyndel. 8.30, vaznik) ; Scherzo (Lalo) ; Selection from The Merry BUDAPEST (558.6 metres) ; 20 kW.-8.0, Review Catholic Bulletin. 8.40, English Lesson. of Books. 7.10, Widow (Lehár) ; Tango, Komm (Darer) ; The 4.10, Talk. 4.40, Concert by the Sovánka Lesson in Dressmaking. 7.40, Talk by M. L. J. M. Three Bears (Coates) ; Waltz, Himmelsfunken Zigeuner Orchestra. 8.0, Reading. 8.30, " Alex- Fever. 8.0, " Joseph en Dothan " (Vondel). (Waldteufel) Scarf Dance (Chaminade) ; Le andra "- Operetta in Three Acts (Albert Szirmav). Cygne (Saint-Saens) ; In the Interval, Advertising 9.0, Weather Report, Time Signal, and News, followed KALUNDBORG (1,153 metres) 7 kW.- Programme Notes. 6.0, Talk by Dr. Busse. 6.25, Prof. Hans by Selections by the Zigeuner Orchestré from the also for Copenhagen (337 metres). --6.30 a.m., Morning Delbrück, Talk : The Relation of the various forms of Hotel Hungaria. Gymnastics. 10.0 a.m., Weather Report. 2.30, Government to War and Peace. " Die Un- 7.0, Instrumental Concert : March, The Handicap (Rosey) ; schuldige " : Play in One CRACOW Act (Heinrich Mann), with (568 metres) ; 1.5 kW. --3.35, M. V. Franck!, Overture to The I talion Girl in Algiers (Rossini) ; Waltz Incidental Music ; " Prinzessin Tessa und ihre Freier ", Talk : The Habits and Customs of the Slavonic Races from Die geschiedene Frau (Lehár) ; Dramatic Poem, Play (Bernhardt Reese), followed by Concert from the of Southern Europe. 4.0, Divine Service Ajax (Brusselmans) ; relayed Selection from Carmen (Bizet) ; Hotel Kaiserhof, Weather Report, News, Time Signal from Vilna. Programme 5.0, relayed from Warsaw. Neapolitan Serenade (Sgambatti) ; Russian Dance and Sports Notes, and Dance Music. Miscellaneous 11.80 (approx.), 6.0, Items. 6.30, M. J. Regula, Talk: (Tchaikovsky) ; Selection from the Novel, " Armed" Close Down. The Foreign Politics of the Previous Week. 6.56, (Olof Böggild), by Carl Schiönuing (Elocutionist) Time Signal from ; the Astronomical Observatory. Selection from Martha (Flotow) ; Waltz from The BERN (411 1.5 kW. metres) ; -3.30, Programme for 7.0, Agricultural Report. 7.5, News and Announce- Dollar Princess (Fall) ; Cavatina for Violin (Ralf) Children. 4.0, Concert by the Kursaal Orchestra. ments. 7.30, Programme relayed from Warsaw. Spanish Dance in C Major, No. 8 (Sarasate) ; Album. 6.29, Time Signal and Weather Report. Medical Programme 6.30, 9.0, relayed from Warsaw. 9.30, Concert blatt (Wagner) ; Rigaudon from the Tordensltjold Talk relayed from Basle (1,010 metres). 7.0, Play in from a Restaurant. Suite (Halvorsen) The Entry March of the Bnjards Dialect. 7.40, Selections by the Kursaal Orchestra. (Halvorsen). 5.20, Peter Ostergaard, Talk : Thw 8.0, Vocal Selections by Mixed Choir. 8.15, Selec- DUBLIN, Call 2RN (319.1 metres) 1.5 tions by the ; kW-1.30, Religious Tendencies of Today. 5.50, Weather Report. Kursaal Orchestra. 8.30, Vocal Selec- Weather Report and Concert of Gramophone Selec- 6.0, News, Exchange Quotations and Time Signal, tions by Mixed Choir. 8.45, News, Announcements tions. News. 7.20, 7.30, Poetry : and Weather Recital by May 6.30, Herr Carl Gad, Talk Modern Foreign Authors-- Report. 9.0, Concert by the Kursaal Pitchford. 7.45, Irish Lesson by Seamus O'Duirinne. Hermann Hesse. 7.0, Chimes from the Town Hall. Orchestra. 9.35, Dance Music. 11.0 ( approx.!, 8.0, Concert of Opera Selections by the Station 7.2, Twelfth Night Concert : Old German Dances Close Down. Orchestra, Gwen Price (Soprano), Joseph O'Neill (Michael Praetorius) ; " The Three Wise Men," Play ; (Tenor). 8.40 (approx.), Orchestral Selection : A Selections (Valentine Hausmann), (a) Pavane, (b), BRESLAU (322.6 metres); 4 kW. --3.0, Review of Kiss for Cinderella (Bucalossi). 9.0, Mandoline Solos Gagliarda ; Suite, Blanchetto musicale (Joh. Hermann Books, by Frieda \\'eiszmann. : 3.30, Concert Over- by Oscar MacRisteard. 9.15, Light Songs ; ture to The Mastersingers by Louis Schein) followed by News. 8.15, Reading from the (Wagner) Fantasia on Spiro. 9.25 Selections by the Station Celeste Or- Novel, " Peter Camenzind " (Hermann Hesse). 8.45, Schubert's Works (Urbach) ; Air from Rusalka chestra. 9.40, Baritone Solos by Norman Apperson. Concert of Light Music : Overture to Light Cavalry e (Dvorak) : Selection fran.Oberon (Weber) ; Kamarin- 9.50, Selections from (a) La Juive (Halévy), (b) Lilac (Suppe) ; Gavotte tendre (Gann); Selection from A 27

www.americanradiohistory.com 16 TR r ll®g0 JANUARY 2nd, 1929. WERild STAMBOUL (1,200 metres) ; 5 kW. -3.30, Concert Programmes from Abroad. Saturday, JANUARY 5th. 4.30, Market Prices. 5.15, Concert of Turkish Music. La belle I-I lène (Offenbach) ; Serenade for Strings 7.80, Weather Report and Time Signal. 7.40, Vocal (Chaminade) ; Waltz Fantasia (Glinka) ; Prestissimo and Orchestral Concert : Orchestral Selections, (a) Gallop ( Waldteufel). 9.45, Dance Music from the Overture to Tannhäuser (Wagner), (b) Adagio soste- Industri Restaurant. 11.0, Chimes from the Town All Times are reduced to Greenwich nuto (Beethoven), (e) lier Ernste Stunden(Beethoven); Hall. 11.15 (approx.), Close Down. Songs ; Orchestral Selections, (a) Légende (Wieniaw- Mean Time and are p.m. except sky) ; (b) Slavonic March (Tchaikovsky). 9.0, News. SATrOWITZ (422 metres) ; 10 kW.-3.0, Music Sachse. Children's Letter Lesson, by Prof. F. 3.35, where otherwise stated. STIITTGART (379.7 metres) 4 kW. -10.0 a.m., Box. 4.0, Divine Service from the Ostra Brama Concert to for Children. News and Weather Report. 1L15 a.m., Chapel at Vilna. 5.0, Programme Gramophone Selections. 12.45, News. LO, Pro - Announcements and News. 8.30, Talk. 6.55, 6.0, gramme for Children. 2.0, Concert : Overture to and Agricultural Report. 7.30, Pro- OSLO (481.5 metres) 1.5 kW.-Programme relayed Time Signal Indra (Flotow) ; Song without Words (Mendelssohn) ; from Warsaw. 9.0, Weather Report by Fredrikastad (434.8 metres), Hamar (555.6 metres), gramme relayed Rhapsodie (Reindl) ; Der Spielmann (Hildach) ; Ich Dance Music. Notodden (411 metres), Poregrund (500 metres) and and News. 9.30. wollt' meine Liebe ergösse sich (Mendelssohn) ; Ballet (448 metres). -5.0, Programme for Children, ; Rjukan ; Wanderlied SAUNAS (2,000 metres) 7 kW -3.0, Concert of " The Sleeping Beauty." Play based on Grimms' from Faust (Gounod) Spielmanns ; ; Frühlingssuite Gramophone Records. 3.15, Talk : The Influence of Greetings. Weather (Horstein) Gruss (Mendelssohn) Fairy Tale. 6.0, Birthday 6.15, evin) (Mendelssohn) Prelude to Die Christianity on our Legends. 3.45, " Radio Patare- Report. Herr Hugo Caspari, Talk : The Lapp 6.30, Lorelei (Bruch). 3.35, Concert, relayed from Frankfurt., jas." 4.30, News. 5.0, Weather Report. 5.2 Market in Sweden. Time Signal. 7.2 ( approx.), 7.0, 5.0, Time Signal and Weather Report. 5.15, Talk by ( approx.), News and Announcements. 5.15, Talk for Orchestral and Vocal Concert from the Works of Popular Orchestral Concert: to Dr. Hoffmann, relayed from Freiburg (577 metres). Farmers. 5.45, Wagner ; Orchestral Selection, Overture The 8.15, ; Vort -Post (G. Karla) ; O Frühling, 5.45, Otto Schwarz reads from his own Works. Lithuanian Song Mastersingers ; Soprano Solo, Elizabeth's Air from Day. so schön-Waltz (Lincke) ; Indian Franz Carl Endres, Talk : Magic of the Present wie bist du Tannhäuser ; Baritone Solo, The Dutchman's Air Snow Romance, Hebomoko (Ernest Reeves) Rêverie Flying Dutchman Orchestral Selection 6.45, Time Signal, Sports Notes and Report on from The Conditions. Eine Ballnacht," Operetta in (Prisovsky) ; March, Spirit of Freedom (Rosey). from Lohengrin ; Vocal Duet from the Second Act 7.15, " Three Acts (Leopold Jacobson and Rob. Bodansky), Selections by of The Flying Dutchman; Orchestral Selection, LAHTI (1,522.8 metres) 35 kW. -4.0, Overture to the Third Act of The Mastersingers; Music by Oscar Straus. the Station Orchestra ; Overture to Tancred (Rossini) ; Wotan's Farewell and Fire Magic from The Valkyrie. metres) ; Waltz, Tout Paris ( Waldteufel) Songs (Bellman). TOULOUSE (Radiophonie du Midi) (389.6 Report, News and Announcements. : Talk. 5.15, Selecti ns by the Station Orchestra. 8.30, Weather 8 kW-12.45, Concert by the Radio Club of Bigourdan 4.35, 8.45, Topical Talk. 9.0, " Luftruten," Sketch (Per -Saëns) Song (Angerkoski) ; Merellä (Merikanto) ; Teas Military March from the Algerian Suite (Saint LykkeSeest). 9.30, Dance Music from the Grand Hotel, ; soivat no suuret surut (Merikanto) ; Sinisellä sillalla Overture to The Thieving Magpie (Rossini) Second Oslo. 11.0 ( approx.), Close Down. Signal. L6, (Kaski) ; Kesäyö kirkkomaalla (Kuula) ; Lastu Waltz (Benjamin Godard). L0, Time ; silmät (Hannikainen); Concert (continued) : Nine Selections fronn Lohengrin fainchilla (Sibelius) Aidin PARIS (Eiffel Tower), Call FL (1485.15 metres) 5 kW. Ristiretkeilijä (v. 5.35, Talk. 6.0, Selec- (Wagner). 1.45, News. 8.0, Market Quotations and -5.0, Pasdeloup Concert. 7.10, Weather Report. 64 : Overture to Tartuffe News. 8,30, Concert : The Fifth Symphony, Op. tions by the Station Orchestra 7.50, " Le Journal Parlé." (La Gye) ; Gipsy Suite (Coleridge Taylor.) 6.30, (Tchaikovsky) ; Selections from Coppélia (Delibes), Recitation. 6.50, Saxophone Solos by Harald Manner - (a) Introduction and Waltz, (b) - Various Slavonic Songs by Reine Volanen. 7.20, Selec- PARIS (Radio- Paris), Call CFR (1,750 metres) ; Themes, (c) Mazurka, (d) Ballad, (e) Scene and Waltz strim. 7.0, of Columbia Gramophone tions by the Station Orchestra ; Ballet Suite from Les 6 kW.-12.30, Concert from La Poupée ; Arabian March (Ganse) Waltz, : Ma by Walter Danuosh, Millions d'Arlequin (Drigo); Musizierende Zigeuner Records Mere l'oye-(Ravel), Santiago (Corbin) ; OneStep, Constantinople(Carlton). Finnish and Swedish, New York Symphony Orchestra ; Bass Solo from The Signal. Concert by " La Dépêche," (Eilenberg). 7.45, News in Borden Stenka 9.0, Time 9.2, and Close Down. Magic Flute (Mozart), by M. Fred ; under the direction of M. Cantenys; in the Interval: Rasine (Glazounoff), by the Don Cossack Chorus; Musical Selections, Le Septuor (Saint -Saens), (a) metres) ; 20 kW.-Programme Pianoforte Solo, Romance Op. 32 (Schumann), by Préambule, (b) Menuet, (c) Intermède, (d) Gavotte et LANGENBERG (468.8 Solo, Etude No. 23 also for Aix-la- Chapelle (400 metres), Cologne (283 Francis Planté ; Pianoforte Finale. 11.0, North African News, 11.10 (approx.), metres), and Münster (250 metres). -12.5, Orchestral (Chopin), by Francis Planté, Si j'étais Demoiselle by Close Down. ; Ukulele Selection, That's my weak- Concert : March, Heil der Zukunft (Frantzen); Maurice Chevalier Hello Montreal, by Ted Lewis - Intermezzo from Naila (Delibes) ; Overture to Le ness now Fox -Trot, VIENNA (517.2 metres) ; 15 kW. -2.15, Photo ; I give you any- Cheval de bronze (Auber) ; Selections from Aida and his Orchestra Fox -Trot, can't telegraphy Transmission. 3.0, Concert : Die Irrtahrt thing but love, by The Knickerbockers ; Fox -Trot, tut man (Verdi) ; Violin Solos, (a) Havanaise (Saint -Saens), um's Gluck- Overture (Suppé) Waltz, Was Eskimos ; One -step, b) Scherzo Tarantella (Wieniawsky) ; Northern Too busy, by the Clicquot Club nicht alles aus Liebe (Ascher) Tirol in Lied und ; - Constantinople, by Paul Whiteman and his Orchestra ; von Suite (Torjussen) In Liebesrausch (Clemus) Pot (Fetr3s) ; Serenade from Der Goldschmied ta de mi Barrio by Pilar Arcos, with Tanz pourri, Offenbachiana (Conradi). 1.80, Hints for the Song, Callen Toledo (Offenbach) ; 'Cello Solos (Squire), (a) Con- 2.0, Programme for Children. 2.40, Orchestral Accompaniment In the Intervals: (b) Romance, Wachtparade der Hutzel- Housewife. Prices and Religious Information. solation), Arthur Wurbs, Talk : The Basis of Wireless Tech- News. 2.0, Market männchen (Ecklebe) Potpourri, Liebe Lust und Dr. Hans Lorenz Lenzen, Talk : Young 3.45, Dance Music by the Joss Ghislery Symphonians; ; Overture (Wichtl) ; Trio Selec- nique. 3.5, Report. Leben (Ischpold) People and Music. 3.30, Talk for Women : Socia- In the Intervals, News. 6.30, Agricultural tion, Du liebe gold'ne Meisterin (Eysler) ; Der lustige Musical Selections. 7.30, Pianoforte Lesson by bility in the Country. 4.0, Line Wallerstein, German 6.45, Posaunist (Lake) ; Potpourri, Perlen vom Donau- their Travels. 4.20, English Lesson by M. Pierre Lucas. 8.0, Talk arranged by the Union March, Aus eigener Kraft (Rup- Artists on Françaises, followed by strand (Kaiser) Prof. F. Hase. 4.45, Orchestral Concert : Overture des Grandes Associations precht). 4.45, August Angenetter, Talk : An Old Style in G Major (Mozart) ; Airs with Market Prices, News and Announcements. 8.15. Night Custom. 5.15, " The Three In Italian Music German 12th accompaniment (Mozart), (a) Misera, dove Concert of Chamber Music, Songs and Dance Men " (Felix 'Timmermann) ; Gertrude Lasch Orchestral Symphonians. In the Intervals, Wise son, (b) Non pin, tutto ascoltai ; Overture in D Major by the Joss Ghislery (Elocutionist), Adelheid Bergmann (Songs to the News. Schubert) ; Songs with Orchestral accompaniment Lute). 5.80, Josef Friedrich Perkonig reads from his Schubert), (a) Suleika 1, (b) Allmacht. 5.30, Prof. own Works, with Introductory Talk by Dr. Erich ; 1.5 kW. Talk. 3.45, 13oerschmann, Talk : Landscape and Culture in POSEN (344.8 metres) -3.25, Korningen. 6.30, Pianoforte Recital by Ignaz Fried- Violin by Mr. Mieczyslaw Paszkiet. 4.16, China- Travels in the Holy Mountains. 6.15, Oskar Recital, mann : Sonata in E Minor, Op. 60 (Beethoven); : on Boy Scouts. 4.30, Talk. 5.0, Programme Pucklitsch : Talk for Workers Ernst Abbe, a Bio- Talk Selections (Chopin), (a) Nocturne in B Major Op. do we relayed from Warsaw. 8.0, Talk for Women by Mme in F Minor, (c) Mazurka in B Minor, Interlude. 83, (b) Fantasia knpoOknow f the Soul f 70VarietyProgr,s a Programme. 9.15, Sabina Swidzinska. 6.20, Musical 8.40, (d) Polonaise in A Flat Major. 7.30, Time Signal, News and Sports Notes. 9.30, Gramophone Records. English Lesson by Dr. Arend. 7.5, Miscellaneous Weather Report and News. 7.35, " The Three 10.30, Orchestral Selections and Dance Music. 12.80 Items. 7.30, Programme relayed from Warsaw ; in Merry Kings " -Play (Heinz Steguweit), followed by a.m. (Sunday), Close Down. the Intervals : The"tre and Cinema Announcements. Dance Music from the Grill Room of the Hotel Bristol 9.0, Time Signal and Weather Report. 9.80, Cabaret and Phototelegraphy Transmission. LEIPZIG (385.8 metres) ; 4 kW. -2.0, Weather Programme. 11.0, Orchestral Concert, arranged by Report, and Concert of Gramophone Selections. 3.0, the Maison Philips. LO a.m. (approx.), (Sunday), VILNA (435 metres) ; 1.5 kW. -2.10, Gramophone' Chess Notes. 3.30, Concert by the Station Orchestra Close Down. Selections. 8.10, News in Lithuanian. 3.25, Pro- Selections from Lucia di Lammermoor (Donizetti) ; gramme relayed from Warsaw. 4.0, Service from the Marche militaire (Schubert) ; Suite,Pastorale (Chabrier), PRAGUE (348.9 metres) ; 5 kW. -3.30, Concert : Gli Ostra Brama Chapel. 5.0, News. 5.20, Poem Recita- Hungarian Dances Nos. 11 to 16 (Brahms) ; Liebes- Orazi e curiati (Cimarosa) ; Selections (Couperin), tions by Mr. Wyszomirski. 5.35, Clarinet Recital by walzer (Moszkovsky). 4.45, Wireless Notes and Talk. (a) L'Artiste, (b) Les Bergeries, (c) Les Moulins à Mr. Sylvestre Czosnowski. 6.5, Selection by Mr. Market 5.20, Weather Report, Time Signal and Labour vent ; Scottish Melodies (Beethoven) Trois pieces Léon Wollejko. 6.30, Prgratnme relayed from Report. 5.30, Programme relayed from Königs- montées (Satie) ; Waltz (Poulenc) Allegro ironico Warsaw. 7.0, Talk. 7.30, Programme relayed from wusterhausen. 6.0, Josef Greif, Talk : Psycho - (Bartok) Serenade (Haas) The Snow Man (Korn - Warsaw. 10.30 (approx.), Close Down. Analysis. 6.30, Prof. Georg Witkovsky, Talk: gold). 4.30, Talk. 4.40, Talk for Workers. 4.50, Lessing. 7.0, Popular Concert by the Station Or- Agricultural Talk. 6.0, German Programme : News WARSAW (1,111 metres) ; 10 kW. -3.0, Talk. 3.25, chestra, under the direction of Wilhelm Rettich. and Recitations. 6.0, Relay of " Die Herzogin von Announcements. 3.35, Talk by Prof. H. Moscicki. 9.0. News, Sunday Programme Announcements and Chicago," Operetta (Kalman), from the Urania 4.0, Programme relayed from Vilna. 5.0, Programme Sports Notes. 9.30, Dance Music relayed from Theatre. 9.0, Time Signal, News and Theatre Notes. for Children. 6.0 Miscellaneous Items. 6.30, ' Radio- Voxhaus. 9.20, Relay of Tzigane Music from Bratislava (300 Chronique," by Dr. M. Stepowski. 6.58, Time Signal. metres): 7.30, Concert ; in the Interval, Theatre Notes. 9.0, MOTALA (1,380 metres) ; 30 kW.-Programme also Aviation Notes and Weather Report. 9.5, News. for Stockholm (454.5 metres), Baden (1,190 metres), and 2XAF and Sports Notes. 9.30, metres), SCHENECTADY, Call 2XAD (2L96 and 9.20, Police Announcements Göteborg (418.5 metres), Malmö (260.9 30 11.58, Weather Report. 12.0 Dance Music by the Oaza Dance Band, directed by (545.6 metres). 31.4 metres) kW.- Ostersund (720 metres), Sundsvall - Sprtalny's Music from New W. Roszkowski. 1L30 (approx ), Close Down. - Music. Programme for Midnigut, Phil York, 4.0, Concert of Light 5.0, 12.30 a.m. (Sunday), Musical Programme from of Old Time Dance Music. ; Children. 5.30, Selection Rochester. L30 a.m., Concert from the Studio. ZURICH (688 metres) 1 kW. -8.0, Chimes from the : of a Shorthand Typist. 6.45, 6.80, Talk The Career 2.0 a.m., Lew White, Organ Recite!, from New York. Zürich Churches. 6.16, Time Signal and Weather Pianoforte Recital, Nordisk dityramb (Sjögren) ; by Mildred Orchestral Concert. 7.35, Concert by Marin in E Flat Minor, (b) 2.30 a.m., Programme Hunt, with the Report. 8.17, Selections (Lundberg) (a), Marimba Orchestra, from New York. 3.0 a.m.,Lucky the Fidelio Jodel Double Quartet, the " Echo v. Marin in E Flat Major, (c) Nocturne. 7.0, Programme and Emmy Brauen (Soloist). Talk. Strike Programme, from New York. 4.0 a.m., Time Bürgenstock " Orchestra of Gramophone Records. 8.0, Topical 8.15, Dance Music. Report and News. 9.10, Gramophone Report. 8.45, Dance Music. Signal 4.2 a.m., 5.0 a.m. (approx.), 9.0, Weather News and Weather Close Down. Selections of Dance Music. ILO (approx.), Close Down. e z8

S*. www.americanradiohistory.com JANUARY 2nd, 1929. WflTehoo 17 Wor-RA Programmes from Abroad. - logical Institute. 5.30 (approx.), Entertainment for BARCELONA (Radio- Barcelona), Call EAJl (344.8 SUNDAY, JANUARY Children. 5.50 (Kalnndborg enh), metres) ; 1.5 kW.--11.0 6th. Weather Report a.m., Cathedral Chimes and Forecast from the Copenhagen Meteorological, Relay. 1L5 a.m., Weather Report and Forecast for Institute. Spain ami Europe, 6.0, Press News and Announcements. followed by Aviation Route Con- 6.15, Time Signal. 6.30, Talk. ditions. 1.30, Musical Selections by All Times are reduced to Greenwich 7.0, Carillon relayed the Iberia Trio; from the Cop- nhagen Town. Hall. 7.5, Concert. Gramophone Records in the intervals. 2.45 to 5.30, 8.15, Pianoforte Mean Recital by Folmar Jensen : Piano- No Transmission. 5.30, Opening Signal, followed by Time and are p.m. except forte Sonata in E Minor, Op. 7 ( Edvard Grieg), (a) Opera Relay from the Gran Teatro ; del Liceo Stock where Allegro moderato, (h) Andante molto, (c) Alla minuetto Exchange Quotations and Market Prices in the otherwise stated. (d) Finale, Interval. molto allegro. 8.45, Dance Music Pro- 8.0 to 8.20, Programme arranged by the gramme by the Palace Hotel Orchestra conducted Catalonian Institute of Agriculture at San Isidro. by Teddy Petersen. In the Interval at 8.20, Concert of Instrumental COLOGNE U.0, Carillon Music by the Station (283 metres) ; 4 kW- Programme also for Relay from the Copenhagen Town Hall. 11.30 Orchestra ; Song and Wedding March by J. Pahissa. Aix-la- Chapelle (400 metres), Langenberg (468.8 (approx.), Close Down. 8.40, Sports News. 9.0 (approx.), Close Down. metres) and Münster (25li metres). -8,45 a.m., Lesson in Self Defence by Dr. Ludwig Bach. 7.20 a.m., KATTOWITZ (422 metres) ; lo kW, -9.15 am., BERGEN (370.4 metres) 1.5 kW.-9.30 a.m., Relay Review of the Programmes of the Week in Esperanto Divine Service Relay. 10.55 &m., Titne SignaL of Divine Service. 11.30 a.m Meteorological Report by Alfred Dormanns. 120 &m., Meteorological News 7.30 a.m., Esperanto Lesson by Report. 1L15 &m., Concert and and Announcements. 7.0, Concert of Alfred Dormanns. 8.0 a.m., Church Chimes. 8.5 of Light Music by the Kattowitz Station Quartet. Orchestral Music. 7.50, Talk, " Topics of the Day." a.m., Catholic Festival of Sacred Music, Choral and LO, Talk. 1.20 and 1.40, Two Agricultural Talks. 8.0, Lecture by Mr. M. Aalin, " Holland." 8.30, Orchestral Items, with Address in the interval. 10.0 2.0, Meteorological Report. 2.15, Relay of Symphony Concert of Vocal Music. Meteorological Concert 9.0, Report a.m., Philological Talk on the German Language by by the Warsaw Philharmonic Society : Over- and Weather Forecast, Late News and Announcements Fritz Worm. 12.0 Noon, Concert of Orchestral ture to " Der Freischütz " -Opera (K. v. and Time Music. M. Weber). Signal, 9.15, Dance Music. 11.0 (approx.), 1.30, Talk. 3.30, Concert. 8.40, Sports News. 8.0. 5.0, Concert. 8.0, Miscellaneous Announcements. Close Down. "The Three Kings," Play based on the Christmas 6..20, " Half an Hour of Jollity," by Professor St. Legend by Felix Ligon. 6.58, Time Signal. BERLIN (Kfnigswusterhausen) Timmermanns and adapted for 7.30, Popular Concert (1,849 metres) ; 40 kW. dramatic performance by Eduard Vetermann and relayed from Warsaw. 9.0, Meteorological Report, -7.55 a.m., Chimes, relayed from the Garrison Church Felix Timmermanns, followed by Late News Press News and Announcements and Sports at Potsdam. 8.0 a.m., Musical Festival Bulletin, Notes. with Sermon, Sports Notes and Musical Programme. 11.0 (approx.), 9.30, Programme of Dance Music. 10.30 (approx.), relayed from Voxhatts, followed by Chimes from the Close down. Close Down. Berlin Cathedral. 10.30 a.m., Morning Concert, relayed from Voxhaus. 12.45, Experimental Picture Trans- CORK, Call 6CK (400 metres) 1.5 kW. -8.30, KAUNAS (2,000 metres) ; 7 kW -2.30, Enter- mission. 1.30 Three Vocal tainment for Children. 3.0, Programme to 2.25, Talks for Farmers from and Instrumental Concert : Choral Selections by for Young Voxhaus. 2.30, Reading of Fairy Tales, from Voxhaus. the Cork National Schools Past People. 3.30, Talk on Health and Medicine by Dr. Pupils' Choir, con - Jurgelfonis. 3.0, Talk. 3.30, Concert Programme. Talk, ducted by Donnchadh O Braoin. 4.0, Talk by J. Ardickas : Economics and 5.0, 11.0, National the I"ife 6.0, Talk. 7.0, Musical Programme, followed by News Anthem and Meteorological Report. 11.15 (approx.), of the People. 4,55, Meteorological Report and Announcements. 9.30, Programme of Dance Close Down. and Press News and Announcements. 5.0, Polish and Music. 11.30 (approx.), Close Down.. Lithuanian News and Information. 5.40, Programme CRACOW (566 metres) 1.5 kW.-9.15 a,m. to 10.45 arranged by Uniin for Defence. 9.0 (approx.), Clost BERLIN (Voxhaus) (484 metres) ; 4 kW. 7.55 a.m., a.m., Relay of Divine Service from Posen Cathedral. Down. Garrison Church Chimes, relayed from Potsdam. 10.58 a.m., Relay of Fanfare from the Church of Morning Notre Dame, KÖNIGSBERG (303 metres) ; 4 kW.- Programme 8.0 a.m., Recital of Sacred Music with Vocal followed by Time Signal and Meteoro- relayed by Danzig (272.7 metres). -8.0 and Instrumental Items and Address, followed logical Report. 11.10 a.m., Relay of am. (KSnigs- by Orchestral berg ordy) : Recital of Sacred Music Chimes Relay from the Berlin Cathedral. Concert by the Philharmonic Society with Choral and 10.30 a.m. from Warsaw. Instrumental Items, Solos and Address. 10.0 (approx.), Orchestral Concert with Solo Items, relayed LO and L20, Talles for Farmers. L40, La Chronique a,m. (Konigsberg only) : Meteorological Report. 10.15 from the Grosse Schauspielhaus. 1.0, Elementary Agricole by Dr. St. Wasniewski. 2.0, Meteorological a.m., Morning Festival. Morse Lesson by Hans Report. 2.15, 11.55 a.m., International W. Priwin. 1.30 to 2.25, Pro- Orchestral Concert relayed from the Time Signal from Neuen. followed by Meteorological gramme of Agricultural Talks. Philharmonic Hall at : 1.30, Practical flints Warsaw. 4.55, Talk " The Report. 3.15, Orchestral Concert. 7.0, Cabaret Pro- for the Agriculturist. 1.45, A Weekly Review of Unity and Systematisation of Advertising Cam- gramme, Artistes : Max Kuttner (Berlin), Karl Napp Market Prices and Weather Conditions. 1.55, Lecture paigns." 6.58, Time Signal from the Observatory. and the Station Orchestra on an Agricultural Topic. 7.0, Relay of Fanfare from conducted by Walter 2.30, Reading of Fairy the Church of Notre Dame, Kelch. 9.15, News and Announcements, Sports Stories for Children. 3.0, Talk. 3.30, Musical Pro- followed by Sports News. 7.30, Concert of Vocal and Notes and Results. gramme. Insstrumental Music. 9.30, Programme of Light and 8.0, Talk. 8.30, Talk. 7.0 (approx.) 9.0, Late News Bulletin from Dance Music. 1230 (approx.), Close Down. Concert or Play, followed by Weather Report and Warsaw. 9.30, Musical Programme relayed from a Forecast, Late News Bulletin and Sports Restaurant. 10.30 (approx.), Close Down. Results. LAHTI (1,522.8 metres) ; 35 kW.- Programme also 9.30, Dance Music. 11.30 (approx.), Close Down. for DUBLIN, Call 2RN (319.1 metres) ; 1.5 kW.-8.30 Helsingfors (375 metres). -8.0 am., Relay of Programme relayed from Church Service. 9.50 am., News from the BERN (411 metres) 1.5 kW.-9.30 a.m. to 10.30 a.m., Cork. Organ Recital by Press. Morning Concert. Herr A. Fleischmann, relayed from St. Mary's Cathe- 10.5 &m., Musical Selections. 10.50 a.m., Weather 12.0 Noon, Time Signal and Meteoro- dral, Cork. National Report and Forecast and Time Signal. logical Report. 12.5, Concert of Orchestral Music. 11.0, Anthem and Weather 11.0 a.m., Report and Forecast. 11.15 (approx.), Close Down. Relay of Church Service (in Swedish). 3.0, Concert by 2.30, Concert by the Kursaal Orchestra. 6.29, Time the Lahti Signal and Meteorological HAMBURG, Call Station Orchestra conducted by Erkki Report. 6.30, Reading or KA (in Morse) (394.7 metres) ; Linko. 3.50, Talk. 4.10, Musical Talk. 7.0, Musical Programme. 4 kW.-Programme relayed Programme. 4.30, 8.45, Sports Results, by Bremen (272.7 metres), Talk. 4.57, Time Signal and Weather Report and Late News and Announcements and Meteorological Hanover (297 metres), and Kiel (254.2 metres). -7,25 Report. Forecast. 5.10, Concert by the Wireless Orchestra. 9.0, Musical Programme. 9.40 (approx.), a.m., Time Signal. 7.30 &m., Meteorological Report, 5.30, Lecture. Musical Programme. Close Down. followed by News and 6.0, 8.20, Piano- Announcements. 7.50 &m. forte Recital by Gorda Veneskoski. 7.45, General (approx.), Talk on Economics and Industry. 8.0 News Bulletin given B$ZIIERS (158 metres) 0.6 kW. -8.30, News, Weekly in Finnish. 8.0, News Bulletin An- &m. Legal Review. 8.15 a.m., Morning in Swedish. 8.30 (approx.), Close Down. nouncements and Sports Notes. 8.45, Concert arranged Festival. 10.0 &m., Talk. 1L55 a.m., International by the Maison Rein -Minoles at Béziers : Selections Time Signal, relayed from Nonen. LANGENBERG (488.8 metres) ; 20 kW,- Programme from 12.05 (for Ham- the Pathé -Art Gramophone Records. 10.30 burg and Kiel), Concert Programme. 12.05 (for also for Aix -la- Chapelle (415) metres), Cologne (2fel (approx.), Close Down. Bremen), Musical Selections by the Station Orchestra. metres) and Münster (250 metres). -8.45 a.m., 2.05 (for Hanover), Gramophone Lesson in Boxing by Dr. Ludwig Bach. BORDEAUX Selections. 1.0, 7.20 a.m., (Radio Sud -Ouest) (238 metres) 1 Programme for Children. 8.25, Relay from Review in Esperanto of the Week's Programmes by kW-12.30, Selections from New the Gramophone Municipal Opera House of " Boccaccio : Alfred Dormans. 7.30 &m. to 7.55 &m., Esperanto Records. 1.45. Close Down. " Operetta in Three Acts by Franz von Suppe, conducted by R. Instruction by Alfred Dormanns. 8.0 a.m., Church Chimes. BRESLAU Krauss and produced by H. Winckelmann, Meteoro- 8.5 a.m., Catholic Morning Recital of Choral (322.6 metres) ; 4 kW.- Programme logical Report, Late News and Instrumental Music with Address in interval. relayed by Gleiwitz (3.29.7 metres). -8.15 and Announcements. the &m.. Chimes 10.50 (for Hamburg, Bremen and Kiel), Meteorological 10.0-&m., Philological Talk by Fritz Worm on the relayed from Christ Church. 1.0, Notes for the "German Amateur Gardener. and Weather Forecast for the North Sea and Baltic. Language. 12.0 Noon, Orchestral Concert. 1.10, Talk. 1.35, Wireless "11.0 (approx.), Close Down. 1.30, Talk. 3.30, Concert. 5.25, Talk by Hulda Chess Talk by Adolf Kramer. 2.0, Programme for Pankok : " Contemporary Phenomena under the Children. 2.30, Talk for Agriculturists. 2.55, Musical HILVERSUM (1,071 metres) ; 5 kW. -2.10, Concert Microscope." Programme. relayed from 6.5, Sports News. 8.0, Play, Late 3.45 (approx.), Talk. 4.10, Concert of the " Concertgebouw," Amsterdam News Bulletin. ILO (approx.). Close Down. Light Music. 8.0, Cabaret Concert by the Berry Jazz conducted by Pierre Monteux. Pianoforte Solos by and Salon Orchestra relayed from the Hotel " Haus Yves Nat. 7.40, Time Signal. 7.42, General News LEIPZIG (365.8 metres) ; 4 kW.- Programme re- Monopol." 9.0, Late News and Announcements. and Communications, Meteorological Report and layed by Dresden. (275.2 metres). 7.30 a.m., Recital 9.30, Programme of Dance Music. 11.0 (approx.), Notes. 7.55, Musical Programme. 10.40 (approx.), of Organ Music. 8.0 a.m., Morning Concert of Instru- Close Down. Close Down. mental Music. 10.0 a.m., Talk by Doctor Koebner : " Constitutional History of the British Empire." BRUSSELS HUIZEN (340.9 metres) ; 4 kW.-Transmits from (508.5 metres) ; I.5 k\V. -5.0, Musical 10.30 a.m., Talk by Doctor Conrad Weygand : ' The Programme by the Orchestra of the Armenonville 5.40 on 1,852 metres. -8.10 &m., Divine Service. Chemistry of Daily Life." Tea 9.30 a.m., Divine 11.0 a.m., Musical Pro - Room, Brussels. 8.0, Children's Entertainment Service Relay. 12.10, Musical gramme. 12.0 Noon, Talk for Farmers. 12.30, Talk. arranged by the Brussels Children's Theatre Selections by the Station Trio. 2.10, Orchestral L& Readings from the Foreign Press. under Selections. Relay of 2.0 (approx the Management of M. Léon Leroy. 0.30. Selections 5.15, Divine Service, relayed from Gramophone Selections. 5.30 Talle. 8.0, Talk. 8.0, by the Station the Juliana -Kerk at Veenendaal (on 1,852 metres). Trio. 7.30, Le Journal Parlé de Radio Wireless Cabaret, Artistes : Agnes Delsarto and Andreas Belgique. Address on the 37th Verse of the 21st &15, Concert : Dumka, Suite based on Chapter of St. Irfon (Vocal Selections), Käte Schindler (Humorous Ukrainian Airs by Akimenko. Matthew's Gospel. 7.10, Talk. 7.40 (approx.), Prose and Verse 10.15, Late News and Orchestral Concert Recitations), Reinhold Balqué Announcements and Press Review. 11.0 (approx.), Programme. 10.25, Epilogue by (Humorous Selections), 9.15 (approx.), Sports Notes Close Down. the Choir, conducted by Mr. Jos. H. Pickkers. 10.40 and Press News and Announcements, (approx.), Close Down. followed by Dance Music relayed from Perlin. 11.30 (approx.), BUDAPEST (558.6 metres) ; 20 kW, Close Down. General News -8.0 a.m., KALUNDBORG (1,153 metres) ; 7 kW.- Programme and Announcements and Programme also for Copenhagen (337 metres). -9.0 a m., Relay LYONS (Radio Lyon) (291 ; 1.3 k \V for Women. 9.0 a.m., Relay of Divine Service with of Morning metres) --7.30, Address. Service with Sermon from Copenhagen. The Radio -Lyon " Journal Parle " with News 3.15, Wireless ' Lyceum " Programme, 10.30 a,m. to and Hungarian Song Recital by 10.40 a.m. (Ralundborg only), Weather Announcements, Press and Theatre Review. 8.0 Vilma Medgyasszay. Report and Forecast from the Copenhagen Meteoro- Instrumental Concert, Soloists : Madame Dueller, A 29

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zb Wfinhegi JANUARY 2nd, 1929. WOEM Time Signal and Sports Notes. '7.0 (approx.), Concert Programmes from Abroad. - JANUARY 6th. followed by Late News and Announcements and Sports ((Cellist)Pianist), M. Camard (Violinist) and M; Testanière Sunday, Notes. 10.30 (approx.), Close Down. Waltz (J. ; " Wine, Women and Song," TALLINN (408 metres) ; 2.2 kW. -8.0 a.m., Divine Strauss). 10.0 (approx.), Close Down. Service Relay. 12.30, Programme of Instrumental All Times are reduced to Greenwich Music. Press News and Announcements. 5.0, MADRID (Union Radio) Call EAJ 7 (434.8 metres) ; 4,45, by (EAJ 22 Musical Programme. 5.30, Talk. 6.0, Concert with 1.5 kW.-Programme relayed Salamanca and are p.m. except Close metres). Relay of Chimes and Time Signal. Mean Time Instrumental and Vocal Items. 9.0 (approx.), (405 -2.0, Down. 2.5, Concert of Orchestral Music with Interlude: where otherwise stated. Jeux d'enfants, Orchestral Suite (Bizet), (a) March, TOULOUSE (Radiophonie du Midi), (389.8 metres) ; Trumpet and Drum, (b) Berceuse, The Doll, (c) Im- 8 kW.-- 12.20, Weather Report and Forecast, News promptu, The Top, (d) Duet, Little Husband and and Announcements. 12.45, Concert of Instrumental No Wife ; Interlude by Luis Medina. 3.30 to 7.0, 4.0, Pasdeloup Symphony Concert Relay from the Music. 1.0, Time Signal. 1.5, Concert (continued). Transmission. 7.0, Chimes. 7.5, Musical Programme Théâtre des Champs Elysées, conducted by M. Rhené 1.45, Press News and Communications. 8.0, Stock by the Union Radio Sextet and Interlude by Luis Batton. 8.30, " Le Radio Journal de France." 8.0, Exchange Quotations and Grain Prices from Paris. Medina. 8.0, Dance Music Programme by the Palermo Sports Notes and News. 8.15, Talk, under the auspices 8.15, News of the Day, supplied by the Parisian Press. Orchestra at the Alkazar. 8.30 to 10.0, No Trans- of the Union of French Associations. 8.30, Orchestral 8.30, Orchestral Concert. 8.o5, Concert arranged by mission. 10.0, Chimes and Time Signal. 10.5, Musical Programme, arranged by the General Association of " L'Association des Commerçants Radio- Electriciens Programme. 12.0 Midnight, Relay of Chimes, followed French Wireless Listeners. 10.30 (approx.), Dance du Midi " : Overture to " Les. Saltimbanques "- by Dance Music Programme by the Palermo Orchestra Music Programme from the Coliseum de Paris. Opéra- comique (Wane) ; In the interval at 9.0, Time relayed from the Alkazar. 12.30 a.m. (approx.) (Mon- 12.0 Midnight (approx.), Close Down. Signal. 10.15, News from North Africa and Late day), Close Down. News Bulletin. 10.30 (approx.), Close Down. PARIS (Eiffel Tower), Call FL (1,485.15 metres) ; 5 kW. MILAN, MI (549 metres) ; 7 kW. -9.0 a.m., Opening Time Signal on 92.5 metres. -0.9S a.m., VIENNA (517.2 metres) ; 15 kW.- Programme relayed Lesson. a.m. to -7.56 a.m., Signal and English Language 9.30 Time Signal on x,489. x5 metres. 5.0, Pasdeloup Concert by Graz (357.1 metres), Innsbruck (294.1 metres), 10.30 a.m. (approx.), Recital of Vocal and Instru- Report. $lagealurt (272.7 metres), ano Lanz (254.2 metres). Signal. Relay. 7.10 to 7.20, Meteorological 7.50, - mental Sacred Music. 11.30 a.m., Time (approx.), " Le Journal Parlépar T.S.F.," with Talks by 9.2U a.m., Choral Selections by the Vienna Boys, Musical Selections by the Milan Station Müller. 11.35 a.m., its Regular Contributors : Health Talk, Police Memoirs, Choir, conducted by Professor Hans 10.0 Quartet. 12.30 to 3.0, No Transmission. 3.0, Opening Sports Notes and Racing Results. 7.56, Time Signal a.m., Classical Concert by the Vienna Symphony Signal. 8.5, Variety Concert Programme. 4.15 Orchestral Concert with Orcnestra and Soloists. 2.30 ( approx.), Experimental Orchestra at the on 32.5 metres. 8.0 to 9.0, P(approx.), Programme by the Tzigane Vocal and Instrumental Solos. Second Hungarian Transmissionof Pictures. 3.U, Orchestral Concert with iaschetteria Toscana. 5.0 to 8.55, No transmission. rendered by Diane Modigliani. 10.28, Time Soloists. 7.0, Time Signal, Meteorological Report and Press News. 7.1.5, Talk. (Liszt) 8.55, Opening Signal. 7.0, Signal on 2,650 metres. 11.15 (approx.), Close Down. Weather Forecast, followed by News and Announce- 7.25, Sports News. 7.30, Time Signal. 7.35, Relay ments. 7.5, " The hirdfancier "- Operetta by T Angelica " of Operetta -Trio : ' 11 abarro," ' Suor PARIS (Petit Parisien) (340.9 metres) ; 0.5 kW.- Zeller, followed by Experimental Transmission of and ' Gianni Schicchi," by G. Puccini ; In the in- Gramophone Records. 8.50, Talk. Pictures. Close Down. Stefani 8.45, Popular 10.30 (approx.), terval: Sports Results and News from the 8.55, Press News and Announcements. 9.0, Orchestral Agency. 10.30 (approx.), Close Down. Concert with Vocal and Instrumental Soloists. 9.25, VILNA (435 metres) ; 1.5 kW. -9.15 a.m. to 10.45 of Divine Service relayed from a Cathedral. 10.55 Programme also News and Announcements. 9.30, The Half Hour a.m., MOTALA (1,380 metres) ; 30 kW.- Symphony Music under the direction of Prof. Estyle, a.m. to 4.20, Programme relayed from Warsaw. for Stockholm (454.5 metres), Boden (1,190 metres). Time Signal, followed by Fanfare from metres), of the Paris Conservatoire. 10.0, Late News and 10.56 a.m., Göteborg (416.5 metres), Malmö (260.9 Selections. 11.0 the Church of Notre Dame at Cracow. 11.5 a.m., metres) and Sundsvall (545.6 metres). Announcements. 10.15, Orchestral Ostersund (720 - (approx.), Close Down. Aviation Notes and Weather. 11.10 a.m., Concert 10.0 a.m., Relay of Divine Service from a Church in of Symphony Music by the Warsaw Philharmonic Stockholm. 1.0, Concert Programme. 3.0, Musical (Radio Paris), Call CFR (1750 metres) ; Society. to 2.0, Three Talks for Agriculturists. Children. 4.55, PARIS 1.0 Programme. 4.0, Programme for 6 kW.-8.0 a.m., General News and Announcements 215, Concert of Orchestral Music. 4.20, News and Chimes relayed from the Town Hall at Stockholm. and Press Review. 8.30 a.m., Physical Culture Lesson Announcements. 4.40 (approx.), Talk in Lithuanian. 5.0, Relay of Divine Service. 6.15, Literary or Dra- Religious Address, followed Selections. 5.20, Items for Children. to " Peer by Dr. Diffre. 12.0 Noon, 5.0, Gramophone matic Programme. 8.0, Incidental Music by Recital of Sacred Music. 12.30, News and An- 5.45, A Quarter of an Hour of Zither Music by Pro- Gynt " (Grieg). 10.30 (approx.), Close Down. nouncements. 12.45, Concert by the Albert Locatelli fessor Witold Jodko. 6.0 (approx.), One of a Series Concert of Zither MUNICH (535.7 metres) ; 4 kW.- Programme relayed Orchestra with Interlude by Bilboquet. 4.30, of Humorous Talks. 8.30, Programme by Augsburg (566 metres), Kaiserslautern (277.8 of Gramophone Records, arranged by " L'Industrie Music by Professor Witold Jodko. 8.56, Time Signal. metres) and Nuremburg (241.9 metres). -10.0 a.m., Musicale " ; in the Interval : News and Announce- 7.0 to 10.30, Programme relayed from Warsaw. 7.0, Relay of Chimes from the Munich Town Hall. 10.10 ments. 6.30, Agricultural Notes. 8.45, Gramophone Talk. 7.30, Orchestral Concert : " Norma " -Over- a.m., The Bavarian Wireless Weather Chart. 10.25 Selections. 7.30, News and Announcements. 7.45, ture (Bellini): 9.0, Aviation Route Report and a.m., Time Signal followed by Weather Report and Guignol Radio Paris. 8.15, Concert of Vocal and Meteorological Report. 9.5, News and Announce- Forecast. 11.35 a.m., Time Signal and Weather Instrumental Music ; in the Intervals : News Bulletin ments from the Polish Telegraph Agency. 9.20, Sports Report and Forecast followed by Announcements of from the Evening Press and Late News and Announce- News and Police Report. 9.30, Programme of Dance Forthcoming Porgrammes. 2.0, Programme of Music ments. 10.30 (approx.), Close Down. Music relayed from the " Oaza " Restuarant, Warsaw. or Literary Reading. 7.0, Musical Programme. 9.0 10.30 (approx.), Close Down. Bulletin followed by Relay of POSEN (344.8 metres) ; 1.5 kW.-9.15 a.m. to (approx.), Late News Time Concert. 11.0 (approx.), Close Down. 10.45 a.m., Relay of Sacred Service. 11.0 a.m., WARSAW (1,111 metres) ;' 10 kW.-9.15 a.m. to .4` Signal. 11.5 a.m. and 11.30 a.m., Two Talks for 10.45 a.m., Relay of Divine Service from a Cathedral. NAPLES, Call 1NA (333.3 metres) ; 1.5 kW.- Agriculturists. 2.15, Symphony Concert, relayed from 10.56 a.m., Time Signal. ü.0 a.m., Fanfare Relay 8.30 a.m. Elementary French Lesson by Prof. Etienne Warsaw. 4.20, Talk. 4.45, Talk. 5.80, Programme from the Church of Notre Dame at Cracow. U.S Verdier. 9.0 a.m., Recital of Sacred Music. 3.45, for Children. 8.0, Programme arranged by the League am., Aviation Route Report and Meteorological Programme for Children. 4.0, Musical Variety Pro- of Polish Youth. 8.20, Talk, relayed from Warsaw. Report. 11.10 a.m., Philharmonic Symphony Concert gramme. 4.30, Time Signal. 7.30, News and An- 7.5, Variety Programme. 7.80, Concert of Vocal arranged by the Department for Education and Culture nouncements. 7.50, Report of the Neapolitan Har- Selections, rendered by M. Mieczyslaw Perkowicz of the Magistracy of Warsaw. 1.0 to 2.0, Three Talks bour Authorities. 8.0- Time Signal. 8.2, Concert of (Operatic Tenor) : Song from " The Jewels of the on Agriculture. 2.0, Meteorological Report. 2.15, Vocal and Instrumental Music : Duetto from Act II Madonna," Opera by Wolff- Ferrari. 9.0, Time Signal. Relay of Symphony Concert by the Warsaw Phil- of Manon Lescaut (Puccini), for Soprano and Baritone, 9.5, General News Bulletin. 9.20, Dancing Lesson by harmonic Society. 4.30 (approx.), Talk. 4.55, Talk rendered by E. Blandi and R. Aulicino. 9.0, Sports Mr. Starski. 9.40, Dance Music Programme. 11.0 on Aviation. 5.20, Orchestral Concert : Fantasia on News. 9.50, Calendar and Review of Forthcoming (approx.), Close Down. themes from " The Haunted Castle " -Opera by Programmes. 10.0 (approx.), Close Down. Moniuszko, arranged by Konopasek. 6.0, Variety ROME, Call 1R0 (447.8 metres) ; 3 kW. -8.30 a.m., Items. 6.20, Talk. 8.45, News and Announcements. ; the German OSLO (461.5 métres) 1.5 kW.-Programme relayed Opening Signal, followed by Instruction in 8.56, Time Signal. 7.0, C. Jablonowski, Talk : Intel- by Fredrikestad (434.8 metres), Harrar (555.6 metres), Language. 9.0 a.m., Vocal and Instrumental Recital lectural Amusements. 7.30, Concert by the Polskie Notodden (411 metres), Porsgrund (500 metres), of Sacred Music. 9.45 a.m., to 12.0 Noon, No Trans- Radio Orchestra. 9.0, Aviation Notes and Meteoro- Rjukan (448 metres). -9.50 a.m., Carillon. 10.0 a.m., mission. 12.0 Noon, Opening Signal. 12.5 to 1.0, logical Report. 9.5, News supplied by the Polish Morning Service Relay from St. Saviour's Church. Trio Selections. 1.0 to 4.0, No Transmission. 4.0, Telegraph Agency. 9.20, Police Information and 4.50, Carillon. 5.0, Relay of Evensong from St. Opening Signal. 4.5 to 5.30, Musical Variety Pro- Sports Notes. 9.30, Programme of Dance Music q.. Saviours Church. 6.15, Meteorological Report and gramme. 6.50, Opening Signal, followed by Press from the " Oaza " Restaurant. 10.30 (approx.) Weather Forecast, followed by Press News. and News and Announcements. 7.10, Talk for Agricul- Close Down. Talk. 7.0, Time Signal. turists. 7.15, Sports Notes and News Bulletin. 7.29, Announcements. 8.30, 0.7 kW. -10.30 a.m., 7.50, Orchestral Concert. 8.30, Meteorological Report Time Signal. 7.31, Topical Talk. 7.45, " Il natale del ZAGREB (309.2 metres) ; Talk by a for Soloists, Choir and Orchestra, Morning Musical Programme. 4.0, Programme of , and Press News and Announcements. 8.45, redentore" Oratorio Cabaret. on a Topical Subject. 9.0, Musical or by Lorenzo Perosi, rendered by the Station Choir and Dance Music relayed from the Club- 8.45, Journalist Amateurs of Wireless. 7.0, Opera Relay Literary Programme. 9.30, Dance Music Programme. Orchestra ; Reading in the Interval. 9.50, Late Talk for the intervals : Close Down. News Bulletin. 10.0 (approx.), Close Down. from the National Theatre, Zagreb. In 11.30 (approx.), General News and Communications and Meteorological PARIS (Ecole Supérieure), Call FPTT (458 metres) ; STAMBOUL (1,200 metres) ; 5 kW. -3.30, Musical Report. 10.0 (approx.), Close Down. 0.5 Programme relayed at Intervals by the Programme. 4.80, Stock Exchange Quotations and kW.- ZURICH (588 metres) ; i kW. -10.0 a.m., Musical : metres), Turkish Music. - following Stations Bordeaux, PTT (275 Grain Market Prices. 5.15, Concert of Programme. 11.29 a.m., Meteorological Report. '`:' Eiffel Tower (2,650 metres), Grenoble (416 metres), 7.30, Meteorological Report and Time Signal. 7.40, Musical Selections by the Station Orchestra. (285 metres), Lyons, PTT History of Music. 8.0, Concert of 11.80 a.m., Lille (264 metres), Limoges Lecture on the 3.0, Programme by the Castellano Orchestra, relayed (480 metres), Marseilles (303 metres), Rennes (280 Classical Music. The Works of Franz Liszt. Piano- Time Signal. News Announcements. from the Carlton Elite Hotel. 6.30, metres), Toulouse, PTT (260 metres). -8.0 a.m:, forte Solos. 9.0, Late News and Religious Address. 8.0, Relay of Musical Time Signal. 9.25 a.m., Close Down. 6.33, and Announcements and 9.30 (approx.), from the Grossmünster, Zürich : The Station Time Signal and Meteorological Report. Recital - International Conductor : Hermann Hofmann. Soloists, Concert. " Le Journal de France STUTTGART (379.7 metres) ; 4 kW.-Programme Orchestra, 12.0 Noon, 1.0, Morning Hermann Achenbach (Baritone) and Viktor Schlatter Economique." 1.30, Musical Programme, organised relayed by Freiburg (577 metres). 10.0 a.m., News Recital. Programme of Light (Organist). 9.0, Meteorological Report, Late by the General Association of French Wireless lis- Musical 11.0 a.m., Press Service from the from the Orchestral Music, followed by Gramophone Selections. and Announcements and teners. 2.30, Symphony Concert, relayed Neue Züricher Zeitung. 9.30 (approx.), Close Down. Concert Hall of the Paris Paper, " Le Journal." ' 2.0, Talk or Reading. 2.30 (approx.), Concert. 5.0, A 30

www.americanradiohistory.com JANUARY 2nd, 1929. TAT®Ilisoo 19 /nOO pIlc1

Two New Marconi and Osram Valves.

" getter " which covers the whole With this fact of the upper portion of the bulb. in mind, the first The characteristics examination made was directed to of an average finding the valve, as issued by the makers in grid-voltage at which grid- current started ; it was found their catalogues, are as follows : that, provided the H.L. 610. anode voltage was A.C. Resistance 30,000 ohms. not less than 6o volts, the grid -cur- Amplification Factor 30 rent Mutual Conductance 1.0 milliamp. per volt. was less than one -fifth of a Maximum H.T. 150 volts. microamp. at grid- r ¡l IHE H.L. 6io is voltages up to a new valve, o.2 volts positive. 1I'i having a satisfactory mutual Two specimens of this valve were This indicated that it will be possible to keep the impe- conductance, and appearing tested ; there was so little difference dance of the valves in the lists of both Osram and between the two that the figures for down to quite a low value by using less Marconi valves ; one only are given. much grid - the particular spe- It was found voltage cimen that we have tested was Mar- that the figures given by the maker than the makers suggest, a provided always coni. As the initial letters of its as typical of the average valve were that the signal - voltage to be name implies, it is intended very closely adhered to by the dealt with is but small, for as will be general work and is suitable, samples examined if we make allow- the case, for example, in pro- a high- frequency vided the circuits with which it is ance for the fact that the impedance amplifier. to be used are correctly as quoted by the makers is measured The following table gives the am- designed, plification for high- or low- frequency amplifi- with zero grid voltage. For re- factor and impedance of cation or for detection. ceiver design it is necessary to take the valve under the various operating conditions ; In the past the series of valves into consideration the fact that the suggested the with " 6io " filaments impedance of a valve, especially one curves reproduced herewith will has been in- supply complete in that the D.E.H. 6io in which the impedance is fairly further data if such are re- has a very much higher impedance high, is dependent to quite a quired. and amplification factor than the surprising extent upon the working Plate next valve voltages adopted in practical use. Valve Ampli- Anode Grid Ampli- Imped- Cur- in the series, the D.E.L. 5cation ante. rment lying at : Volts. Volts. 61o. This gap has been accen- Factor. (A. tuated by the revision and improve- High 150 -0.5 28.5 21,000 3.0 4 MARCONI Frequency. 120 -0.5 29 28,000 1.7 ment of the characteristics of the H L.610 series as a whole, so that the H.L. Low 150 -1.5 29 28,000 1.8 Frequency 120 -1.5 30 33,000 1.3 61o,. which is intended to fill this Ñ FILAMENT 0.104 AMP AT 6 V. gap, should be welcomed by very wa 3 301 It will be noticed .that the mutual many valve- users. f G J ç conductance with maximum anode The valve falls roughly into the LA 4' voltage v O and minimum grid -bias same class as the well-known D.E. F 2 202. Z rises to the very high value of 1.35 W 5b, but consumes far less filament s Zf a milliamps. per volt. Used with a current and offers better character- w standard high -frequency transformer istics that its predecessor. ';,,A' , of Wireless World pattern, with an In 10ó appearance the new valve is 'z extra turn or two on the primary, indistinguishable /IEI 0 from the other <° %%í%ii these figures lead one to expect an members of the series ; the only dif- amplification of about sixty times ference presumably consists in -4 3 2 1 0 + the GRID VOLTS in one stage ; - for this purpose the closeness of the grid -mesh, and this valve is eminently suited. cannot be Characteristic curves of the Marconi seen on account of the H.L. 610 valve. For detection and low- frequency A 31

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JANUARY 2nd, 1929. 20 WPM Valves We Have Tested. protected from inspection by the The following table gives recom- amplification in receivers using re- " getter." Again it was found that mended working conditions for three with sistance- capacity coupling this valve the valve was quite hard, there be- different plate voltages, together offers .a very acceptable compromise ing no reverse grid- current, and the impedance and amplification between the warring claims of high it was possible to make the grid factors found under those conditions ; amplification per stage on the one positive, to the extent, this time, of it will be seen that these latter figures hand, and proper reproduction of about half a volt, before any measur- depend, as usual, upon the working high notes on the other. An anode able grid-current flowed. voltages used. resistance of some 150,000 ohms when the valve is an amplifier, or MARCONI Anode Amplifi- Imped- it is an anode D.E.L.610 Anode Grid Current. catign ante 250,000 ohms when 1 Volts. Bias. will be found very satis- (mA.). Factor. (ohms). detector, 10 FILAMENT 150 -4.5 4.5 12.5 10,600 factory. Some care should be used 0105 AMP. AT 6V Ñ8 120 - 2.5 3.3 13.0 11,500 2.7 13.6 12,700 in "following this valve, used either a 100 -1.5 as amplifier or grid detector, by a w6 transformer, as its impedance, < 11111 y iii is given on though not perhaps prohibitively Further information the curves, from which the above high, is definitely on the high side iLr O 1-16 figures have been deduced. for such use. fl 4z This valve' is not the best one to to note that the O4 It is satisfactory P!'1i41M, choose for high- frequency amplifi- refused to give any 4 valve entirely cation, as the maximum amplifica- of softness, either in the indication <2 _R mis 2Ú tion that can be expected from it, form of reverse grid- current, or of , rami. "Al s even with a high- frequency trans- plate current when o " creeping " of dG13/ former designed to suit it, is very in it 4 3 2 1 0 + a. high anode voltage was used 29 8 7 6 5 GRID VOLTS decidedly less than that which can conjunction with zero grid bias, even be attained from the next valve in though the makers' maximum Characteristic curves of the Marconi D.E.L. 610. the series, the H.L. 61o. As a grid anode -voltage rating was consider- a transformer, or data for the detector preceding ably exceeded in this test. The manufacturer's -coupled L.F. am- valve are as follows as a transformer 610. :- plifier, it is very suitable indeed, The D.E L. D.E.L. 610. A.C. Resistance 7,600 ohms. and in such positions will give of its This is not an entirely new valve, Amplification Factor 15 - low- magnifi- but an old one redesigned, to the Mutual Conductance 2.0 milliamps. per volt. very best. Where a Maximum H.T 150 volts. as is great improvement of its character- cation L.F. stage is wanted, case, after an anode recti- ; the factor has As before, the makers measure often the istics amplification with been raised a little, and the imped- amplification factor and impedance fier, this valve, in conjunction ance has been lowered a good deal at anode volts ioo, grid volts zero, a plate resistance of some 50,000 the earlier model was pro- so that the actual working values ohms is suitable. It is particularly since in these duced. Further, it is now rated to cannot be expected to be quite so fitted to precede a pentode as its low im- volts instead good ; in addition, the valve tested specific circumstances, withstand 15o H.T., the of maximum of 120. did not come up to specificati xn, pedance ensures that, even with the original the In appearance it is indistinguish- having an impedance of 9,50o ohms high input capacity of that valve, able from the H.L. 610 just des- and an amplification factor of 14.3 high -note loss will not rise to appre- cribed, the electrodes as before being under the conditions specified. ciable dimensions.

Loud Speakers. Amplification. Impedance in Moving Coil Push -Pull The question of impedance in a moving coil The possibilities of transformer amplification at a recent meeting by Mr. R. Garside, of loud speaker was discussed were fully demonstrated of the Croydon Wireless and Physical Society Messrs. Ferranti, Ltd., at the last meeting of MEWS FROM of The de- on the occasion of a demonstration the North Middlesex Radio Society. Baker's moving coil instrument, demonstrated by monstration receiver consisted of a screened In the discussion, the followed by an anode bend Mr. C. H. P. Nutter. grid H.F. stage CLÚoSo effect of unmatched impedance was mentioned, detector, and the novel method of adjusting THE decision as to rectification. The out- with an idea of arriving at some this gave almost perfect how to ascertain whether the moving coil im- put from the detector was passed via a trans- high or too low by the quality former to the first L.F. stage of push -pull ampli- pedance was too a similar stage of reproduction. fication. and thence to further of the Swindon and Visitors are warmly welcomed to any of the employing four 1,700 -ohm valves, consuming 20 carried out at the meeting ob- District Radio Society on December 11th. Two- Society's meetings. Particulars may be watts, which fed a moving coil loud speaker. with the Hon. Secretary, Mr. H. T. P. The difference between valves in parallel and valve amplification was used in conjunction tained from a moving coil loud speaker. By means of a Gee, 51 -52, Chancery Lane, London, W.C.2. in push -pull was emphasised. The fact that differ- in the two halves of the push -pull multiple switch three tone firms, carrying the current ent makes of pick -up could be tried on the 0000 transformer cancels out, thus retaining the Demonstrated. was pointed out as one same type of record with a minimum of delay New Marconi Set maximum inductance, between each. The demonstration was fol- At a recent meeting of the IlforI and Dis- of the advantages of this method of amplifi- - lowed by a debate on the best type of tone trict Radio Society, Mr. Youle, of the Marconi cation. arm and subsequently by a demonstration in phone Co., Ltd., lectured on screened valves, In the near future the Society will carry out of the Marconi 61 re- several of the which one of the best known types of gramo- and gave a demonstration a comparative demonstration of beside a ceiver In conjunction with a Marconi moving latest types of loud speaker. phone failed to satisfy when tried moving coil loud speaker. coil loud speaker. Iton. Secretary: Mr. E. H. Laister, "End- the Society's membership has in- Station Rd., Winchmore Hill, N.21. A receiver consisting of separate units is Although clilfe," 7a, 0000 shortly to be placed at the disposal of mem- creased of late, there are still vacancies for bers for experiment. enthusiasts, who should write for full particu- Pick -ups Compared. Hon. Secretary, Mr. C. E. Largen, experiments with Hon. Secretary : Mr. M. Hill, Windyridge, lars to the Some interesting comparative 16. Clements Rd., Ilford. gramophone pick -ups now on the market were Okus, Swindon. A 32

www.americanradiohistory.com JANUARY 2nd, 1929. Wfip@Il@@0 21 Wev oC

NEWS FROM ALL QUARTERS.

By Our Special Correspondent. The Brussels Scheme. -British Wavelength Changes.- Bristol and 5WA. -More About the Regional Scheme.- Wanted : A Name. P.O. and the "Pirate " Problem. A Memorable 13th. wavelength, and a few sets will probably pean ether for weeks before the plan We are about:to bid adieu to an old be wrecked before their bewildered actually friend came into force. In fact, som- -the Plan de Geneve. With an en- owners discover that this time the set is stations were so zealous in the matter gaging disregard of pppular superstition, blameless. that they adopted their newly allotted the Union Internationale de Radiophonie 0000 wavelengths for regular broadcasting introduces the Plan de Bruxelles on " P.P." Optimistic. some considerable time before the date January 13th -a Sunday-on which date Captain Eckersley is highly optimistic fixed. the wavelength pack is to be reshuffled This time rehearsals are forbidden, once concerning the new arrangement, going so even more. In the majority of cases the far as to say in the wee sma' hours. changes will not that, " humanly speaking, be revolutionary, for the the scheme seems bound to work." 0000 committee, which has been meeting at Brussels under We can only hope he is right. At all The New Wavelengths. the chairmanship of the events, the change can hardly for indefatigable M. Braillard, thoroughly be the Below is the list of wavelengths which will come force endorses the Tennysonian sentiment . into on Sunday, January 13th : -- " The little more, how much it is ; the FUTURE FEATURES. Metres. Station. Kilocycles, little less, and oh ! what world's away." London and Daventry. 1,562.5 Daventry 5XX .. 192 Talking in kilocycles, 482,3 Daventry 5GB .. 622 it is the little JANUARY 6TH.- National more or Sunday League 401.1 Glasgow .. .. 748 the little less which makes all Concert, relayed from the London 378.3 Manchester .. 793 the difference between an unadulterated Palladium. 358 London .. 838 signal and a JANUARY 9TH. -A Talk on International 323.2 Cardiff 928 nightmarish heterodyne. Affairs. 311.2 Aberdeen .. 964 0000 JANUARY 10TH. -Illustrated Talk oú " How 302.7 Belfast .. 991 The Case of Aberdeen. to Play Syncopated Music." 288.5 Relays and JANUARY 12TH. -Six Strange Saturdays. Bournemouth 1,041 The biggest changes among the British -I. 243.9 .. Newcastle .. .. 1,230 stations are those affecting Aberdeen and Daventry Exp. (5GB). 0000 Newcastle. Aberdeen JANUARY 8TH.- ` Carnival," a play. will occupy what JANUARY 9TH. -Spain The Plight of Bristol. is virtually Newcastle's in Music of the present wave- 20th Century. It has always been a sore point length, a drop from 500 to 311.2 metres, JANUARY 10TH.-Orchestral Concert of with Music by Bristolians that their city is but Aberdonians who might be inclined Rameau and Gluck. denied a to Cardiff. broadcasting studio of its own. The resent such a giddy fall can take heart of JANUARY 0T8. -New Year Programme. B.B.C. has grace from the thought their decreed that they shall listen that new Manchester. to Cardiff, and from time to time has wavelength is to be an exclusive JANUARY 10TH. -Ha1l6 Concert, relayed one, supplied an inducement in the shape of thereby saving them (let us hope) from from the Free Trade Hall. JANUARY 11TH.-Scottish Programme. special programmes from 5WA interference from any source whatsoever. employing 0000 Newcastle. Bristol artists. But nature has stepped JANUARY 8T11.-Musical Comedy Old and in as a common enemy which even the An Honour for Newcastle P New. Glasgow. British Broadcasting Corporation seems Newcastle will have the honour of JANUARY 958.-Concert of French Music. unable to vanquish. possessing the lowest wavelength ever Aberdeen. For some unexplained reason, nature used by a B.B.C. station, viz., 243.9 JANUARY 7TH.- Scottish Programme. objects to the passage of ether waves metres. Belfast. from South Wales JANUARY 7TH.-Programme of Elizabethan to Somerset, .a fact The only station to retain its present Music. which is specially tantalising to Bristol wavelength will be Daventry 5XX ; JANUARY 12TH. -An Irish Programme. listeners when they know that Cardiff is among the other main stations the ten- staging a programme for their particular dency will be a slight drop id wave- benefit. length, so small in most cases that it may worse, for among British stations the only 000') pass unnoticed in two the general run of un- which have not filed a complaint at Why Bristol Prefers selective sets. headquarters in Daventry. regard to heterodyning Nature's contrariness 0000 during the past month are Belfast and in this matter The Relays Combined. London. came into unusual prominence during the 0000 recent Bristol Radio Week, when Cardiff The same day will see the concentration placed all its resources of all the relays, at the call of its together with Bourne- Rehearsals Forbidden. opposite neighbours, with disappointing mouth, on the national common wave- I understand that there are to be no results. length of 288.5 metres. No doubt there preliminary tests with new wavelengths. Many Bristol listeners will be many listeners have given up to these who have When the Geneva plan was in the air, 5WA in disgust, preferring the never " heard tell a more " of national common there was a terrible hubbub in the Euro- reliable though frequently heterodyned A 33

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22 Wfipg®Mg5 JANUARY 2nd, 1929. W.9)1AZ transmissions of 5XX. Meanwhile they thought of including a licence in the tween these informal concerts and the are casting pious hopes towards the stocking. People don't generally give genuine home product lies in the quality Regional Scheme, trusting that 5WA's licences at Christmas, even for dogs, or of the output! 0000 high power successor will make the guns, or menservants. The inference is Severn look silly. that the army of pirates has been A "Great Play " of France. 0000 augmented, unless all the Bobby's and Rostand's " The Fantasticks " is the Regional Station for Wales. Jimmy's made a stand for righteousness. fifth in the broadcast series of World's a The Western Regional Station is still One can conjure up a fine picture of Great Plays. It is to be heard by an airy nothing. I hear that one member noble youth declining to tune in 2L0 be- listeners to 2L0, 5XX, and other stations of the B.B.C. Governing Board has sug- cause he has no licence, but the picture on January 15, and to 5GB on January of " touching 16. gested that it should occupy a site in the would need a good deal coon Rhondda Valley, with the object of en- up " to make it convincing. suring good reception for the miners, 0000 Enter a Mongoose. A new and unexpected patron of most of whom use crystal sets. That the A Way They Have in "S.A." station will be in South Wales is a prac- broadcasting made a public appearance Despite the almost daily prosecutions, during the transmission of a Mozart tical certainty, but no move to pin it down the Post Office is only nibbling at the to any definite locality has yet been do- Symphony from the Wellington Hall, pirate problem, which grows bigger Belfast, a few days ago. Half -way cided upon. to do so 0000 every month, and will continue through the piece a large and well -fed as portable and frame aerial sets increase Ulster. mongoose ambled on to the platform, Lucky in popularity. and, after stropping his whiskers in per- l'he regional stations are to be pro- In South Africa the unlicensed listener functory fashion, stepped down and dis- ceeded with one by one; that is to say, has been almost non -existent since the wireless appeared beneath the seats in the the London station will be operating regulations required that the audience a auditorium. Fortunately, the before the Northern Regional is even licence must be produced whenever were so engrossed in the music that the begun. The Scottish Regional will prob- set, accessory, or component is pur- unusual visitor remained unnoticed, ably be the next, and the Western will chased. otherwise the microphone might have follow fourth. There is a sufficiently 0000 passed on some queer interpollations not making the Re- good reason for Ulster Time Signals Disputed. included in the Mozartian Score. gional Station the last on the list. The B.B.C. lias encountered its first The mongoose was one of a number Northern Ireland is nearer to the which are kept at the Wellington Hall than any other region horological critic. This gentleman, writ- Listeners' Paradise complains that the to wage war on rats. to -day. Not only is it sheltered from ing from the Midlands, 0000 enjoys in time signals are inaccurate, he having European' interference, but it ap- A Microphone Record. reliable and effec- checked them by his own watch. It 2BE one of the most sometimes I hear fourteen microphones now operating in the United pears that the discrepancies that -the tive stations much as ,!,th of a second, largest number ever employed in an out- Kingdom amount to as 0000 and the new critic charges the B.B.C. side broadcast -are to be used at the with permitting the intrusion of the ceremony of the enthronement of the new Wanted : A Better Name. Archbishop of York, Dr. Temple, for- are confident hopes at Savoy Hill " human element." There He feels so strongly on the matter that merly Bishop of Manchester, to take place that the whole of the Regional Scheme licence on 10th. The 1930, he proposes to take out a wireless at York Minster January will be in operation by December, if he is given which is to be relayed to of " Broadcasting to receive foreign stations enthronement, before the completion an undertaking that not a penny of the Daventry and all stations of the Northern House." will incorporate the procedure House " re- money goes to the B.B.C. grouping, Talking of " Broadcasting 0000 which has been associated with this his- minds me that we may not be talking of for many hundreds of longer. The toric ceremony it as such for very much Shakespeare in Music. years. The actual installation and en- name is being used at present merely for The songs in Shakespeare's plays have The B.B.C. thronement will be performed in the want of something better. been set to music by composers all over choir, after which the Archbishop will feel that a more national and precise de- the world; this music is to form a pro- them his discovered, speak to the clergy and give signation is only waiting to be gramme entitled " The Food of Love." - it yet. blessing from the throne. He will after- though nobody has lighted upon which 2L0 will broadcast on January 7. wards speak, from the choir screen, to 0000 Humperdinck, Tedesco, Mendelssohn, the congregation in nave and transept. Quilter, Atmosphere. Balakirev, Sullivan, German, 0 A Propitious and Vaughan Williams are to be re- 1 have not heard that any reward is presented. The Hallé Orchestra. no doubt anyone who and the Hallé being offered, but O O 0 Sir Hamilton Harty nas an acceptable brain wave will be very Orchestra will broadcast on January 10th kindly treated at headquarters, and may No Place Like Home-Except 5GB. from Manchester their programme, which even find himself in that mecca of the Listeners who have never yet tuned is to be relayed to 2L0 and 5XX, includ- blessed -the Savoy Hill canteen. And, in to Daventry 5GB when one of the ing Mendelssohn's " Italian Symphony " once there, he may be vouchsafed an oven " Old Folks " programmes is being re- and Brahms' Violin Concerto in D, with better idea. layed from the Birmingham studio, Arthur Catterall as soloist. In the same 0000 thinking, perhaps, that it will be noth- programme will be given Eric Fogg's A Pertinent Question. ing more than a stereotyped kind of song " June Twilight," which was heard by Since December 25 there must be recital, should hear the programme of listeners to the Promenades last summer. thousands of folk who are saddled for the January 11, presented by the Birming- Mr. Fogg will conduct this work in person. first time with the awful responsibility ham studio chorus and orchestra. It ooco of operating their own wireless set, like should be an eye- opener in programme State. presentation. B.B.C. and the Variety a frail bark upon an ocean of ether. The B.B.C. begins the New Year with of these The informality of home life is the Quitting poetry, how many a promise of more amicable relations with chappies have licences? keynote of these programmes, and the 0000 human element is introduced to such an the theatrical and variety interests. extent that the most amusing mistakes On Saturday, January 12th, Jack Mor- Licences as Presents P occur. Sometimes trouble crops up whin rison, in impressions, will supply the It would probably be safe to wager the song required cannot be found, and variety turn to be relayed from the stage that not 25 per cent. of the " affec. at other times there is a rousing discus- of the London Palladium to 2L0. 5XX, uncles," loving grandmas," etc., who be- sion as to " what number it might be in and other stations. Further Palladium stowed wireless this Christmas ever the red book." The only difference be- broadcasts are being arranged. A 34

www.americanradiohistory.com JANUARY 2nd, 1929. WAp@Ilsoo 23 WollIlcl

FITERS To . , THE -DIToR.

9U{II(fn- lll6' fillllplltutntuniur,,unttll(((IUIIlfl111(IIIIIIIfIIIII1liIIIIIÌ - f ! li The Editor does not hold himself responsible for the opinions of his correspondents. Correspondence should be addressed to the Editor, "The Wireless World," Dorset House, Tudor Street, E.CA, and must be accompanied by the writer's name and address. DIODE RECTIFIER. But I, =I and f( & -D+ eg)= f(AD), and so, whatever Sir, -In view of the recent discussion in your pages regarde f may mean, -lug the merits of the diode rectifier, and previously regarding D +µg =A +D rectifiers of other sorts, I beg to submit the following idea for A- the benefit of your readers. .D= 2 In other words, we llave a perfectly linear relation between the grid voltage and the rectified anode voltage. This is independent of the shape of the characteristic curve, and only requires that should remain constant around the lower bend, Nthich is practically true, even though ,the resistance varies considerably. It is surely a negligible drawback that an extra valve and independent filament and grid bias batteries are required, and the fact that these components carry low frequency potentials should present no more difficulty than is met with in the various condensers, chokes, etc., in existing arrangements, and the indirectly heated kathode valve provides a solution of the difficulties with the filament, circuit. The advantages claimed are : (1) Linear rectification for A.C. inputs between zero and a peak voltage equal to the grid bias. (2) Sensitivity comparable with that of an anode bend rectifier having an anode resistance equal to that of the valve under rectifying cgnditions, i.e., several times the normal valve resistance. This is considerably higher sensitivity than can be claimed for the diode. (3) Unlike the diode, it applies no damping to the preceding tuned circuit. Stratford -on -Avon. P. G. DAVIDSON. BROADCASTING IN ITALY. Sir, It might interest you to know of the regulations recently made by the Italian Government in connection with Suppose that both valves in Fig. (a) have identical characteris the improvement of radio transmissions. tics and that they are both biased to the origin of the anode Last June a law was current drafted, subsequent to a proposal made curve, i.e., B in Fig. (b). Considering this figure as by the special State Committee for a grid volt /anode current the Supervision of Radio curve, we may say that g is the grid Transmissions, according to which the " voltage reckoned from the bias E.I.A.R." (the Italian point as zero, and considering B.B.C.) are allowed to transmit, on paying compensation, the sanie diagram as an anode volts /anode current curve, taken all performances given in the Italian . theatres, etc. at. the appropriate grid voltage, we may say that A is the Further, in order anode to make transmissions more perfect, from voltage reckoned from $ as zero. an artistic. point of view, steps We may consider are being taken to eliminate, that the anode current I is related to the as far as possible, all disturbances from telegraphic grid and anode voltages by some expression stations. of the form : All spark stations will be provided with valve transmitters; I =l(A +µg) measures will be taken to keep the wavelength of such stations where µ is the amplification factor and f represents some as constant as possible and to avoid harmonics produced by function unknown. them disturbing wireless It is listeners on the 200 -500 waveband. self -evident that the anode current is at all times the In addition, it is proposed same for both valves, and the to study the possibility of closing that sum of the two anode volt- down, save in urgent cases, telegraphic wireless ages, i.e., the H.T. volts across the two valves transmitters in series, is from the hours 2000 to 2330, thus permitting a purer audition constant, of programmes. Now, when The elimination of disturbances produced a valve having a resistance in its anode circuit by tramways also comes under has its grid voltage increased, its study. anode voltage must fall by It is intended to form a staff of inspectors some amount, which we may call D, to help listeners so that when a positive to get the best results for the audition of programmes. voltage g is applied to the grid of V, its anode current, is represented I A new station of 50 kW. will be built in Rome, to be by opened on October I,=f(A 28th, 1929. It is also proposed to erect a -D --, g) short -wave Marconi beam station for transmitting national and for V, where g is fixed at 0 ( =B, of cou °se), and where 1rogrammes anode voltage to the Colonies and to America, for the benefit becomes Al-D, of Italian residents over there. 13= /(A +D) Milan. PAUL CHALLANDES. A 35

www.americanradiohistory.com WApemo JANUARY 2nd, 1929. JoIld

" The Wireless World " Supplies a Free Service of Technical Information. The Service is subject to the rules of the Department, which are printed below; these must be strictly enforced, in the interest of readers themselves. A selection of queries of general interest is dealt with below, in some cases at greater length than would be possible in a letter.

Using the Abacs. H.F. amplifier; "free" grid bias will Short Aerials. be neces- spite of my efforts to increase the selec- fitted with 6- no longer be possible, so it will In ufy D.C. mains receiver is to conform tivity of my receiver I still find that volt valves consuming 0.25 amp.; sary to alter the connections to those given in Fig. 1. the waveband occupied by the local filaments are connected in series. I wide. Do you of station is excessively now wish to substitute for one advise me to.put up a shorter aerial? them a valve taking 0.1 amp., and T. B. to understand that it is necessary It is often recommended that in the shunt its filament with a fixed resist- vicinity of a transmitting station a com- ance. How can the value of this re- should be used, to paratively short aerial sistance be ascertained? It seems but we are not at all sure that this is the me that the resistance " abacs " which best cure for interference troubles. It recently appeared should be useful for retain the receptive powers I seems better to solving problems of this kind, but of your present large aerial (which will cannot see exactly how to set to work. always be a help in receiving distant J. G. stations), but on wavelengths where inter- Your problem is to choose a resistance ference is bad you can make provision of such a value that the resultant resist- for coupling it very loosely to the grid ance of filament and shunt will be equal circuit of the first valve. Provided this to that of any other valve in the series coupling is sufficiently loose, there is no circuit. This can easily be done with the real reason why the large aerial should in- help of Abac No. 11 (October 3rd). troduce more interference from the local The procedure is first to find out the station than would a short aerial tightly resistance (in ohms) of the valve fila- coupled. ments by dividing voltage by current (in caoo amps.). If the new valve is rated at 6 Fig. 1.- Modified grid circuit of Working in the Dark. its resistance will be 60 " Europa III' receiver. volts, 0.1 amp., help me to trace the cause of a 0.25 amp. valves already in Can you ohms. The considerable falling .off in signal use will have a resistance of 24 ohms. we will imagine strength? My set is a 1 =v -1 combina- Referring to the abac, RULES. tion, which normally gives good loud- that the figures shown in it are multiplied (which must deal with resist- (1.) Only one question speaker reproduction on the three by 10, thus bringing it up to the a single specific point) can be answered. Letters have Now set a straight- must be concisely worded and headed " Infor- nearest stations. All connections ance range required. been and tested as far as at 60 on the left -hand mation Department." examined edge to register (2.) Queries must be written on one side of possible, and everything appears to centre line ; the point and diagrams drawn on a separate line and at 24 on the the paper, in The batteries are a few on the right -hand line will sheet. A self-addressed stamped envelope must be order. of intersection for reply. 1 do not think, they resistance of the shunt, be enclosed postal weeks old only, so give the correct (3.) Designs or circuit diagrams for complete can be responsible. D. V. L. which is 40 ohms. receivers cannot be given ; under present-day conditions justice cannot be done to questions From your concluding remark we as- 0000 of this kind in the course of a letter. sume that you have not measured the volt- (4.) Practical wiring plans cannot be supplied and, in spite of The " Europa III." or considered. age of your batteries, as what you say, we are inclined to think 1 should like to use 2 -volt (5.) Designs for components such L.F. If possible, chokes, power transformers, etc., cannot be that they must be responsible for your valves throughout in the " Europa supplied. to objec- the construction or trouble, although it is quite impossible III " receiver. Is there any (6.) Queries arising from However, you tion? If not, will it be necessary operation of receivers must be confined to con- make a definite statement. structional sets deseribed in " The Wireless would be well advised to measure the to make any modifications? C. W. World " or to standard manufacturers' receivers. remarks in his Readers desiring information on matters various voltages, and if the fault is found Subject to the author's you can fairly opening paragraph, you can certainly use beyond the scope of the Information Depart- to lie elsewhere, we think ment are invited to submit suggestions regarding suspect that one or more of the valves these valves. The only modification subjects to be treated in future articles or necessary is in the grid circuit of the paragraphs. has partially lost its emission. A 36

www.americanradiohistory.com ,. IPiX+r.M+wtNS,i 4 rr ;b kt I 4 4044":141i rele AND RADIO REVIEW (161f Year of Publication)

No. 489. WEDNESDAY, JANUARY 9TH, 1929. VOL. XXIV. No. 2. freedom Editor: HUGH S. POCOCK. from interaction with its consequent distortion, Assistant Editor: F. H. HAYNES. which is often more distressing than that due to defects in detection. Editorial Offices: 116 -117, FLEET STREET, LONDON, E.C.4 Against this we have the drawback of Editorial Telephone: City 9472 (5 lines). insensitivity, or, perhaps more accurately, the fact that Advertising and Publishing Offices: the diode, while efficient enough in performing its func- DORSET HOUSE, TUDOR STREET, Telepoone: LONDON, E.C.4. tion as a rectifier pure and simple, does City 2847 (13 linen). Telegrams: Ethaworld, Fleet, London." not amplify, as do either of the principal competing ; COVENTRY : Hertford devices to make Telegrams: "Cyclist, Street. Coventry." Telephone: 5210 Coventry. good its shortcomings in this direction, it may be regarded BIRMINGHAM: Guildhall Buildings, Navigation as essential Telegram,: "Autepress, Birmingham." Street. to add another valve, over and above the Telephone: 2970 and 2971 Midland. number we generally consider necessary MANCHESTER : 260, Deansgate. to achieve a Telegrams: "I101e. Manchester." Telephone: 1970 City (4 linee). given object. GLASGOW: 101, St. Vincent Street, Telegram,: "Iline, C.Z. Glasgow." Telephone: Central 4867. The Demand for Simplicity. PUBLISHED WEEKLY. Subscription Rates : Home, In 17s. 4d. ; Canada, 17s. 4d. ; attempting to reach a conclusion as to other countries whether the abroad, 1gs. 6d. per annum. two- electrode rectifier is sufficiently attractive to survive, Entered as eecoad Class Matter at New York, N.Y. As many we cannot ignore the fact of the currants and apparatus described in these pages are covered that it draws a considerable patents, readers by are advised, before making use of them, to satisfy themselves amount of energy from the tuned circuit that they would not be Infringing patents. which feeds it, and consequently introduces a damping effect serious enough to reduce selectivity, in spite of the observance CONTENTS OF THIS ISSUE. of precautions which have been described. In view of EDITORIAL PAGE VIEWS .. 25 the ever-growing need for this quality, it is not BUILDING A PICTURE RECEIVER. unlikely By F. H. HAYNES . .. 26 THE DIODE RECTIFIER. By H. L. KIREE that this defect will unfavourably prejudice that con- THE MICROPHONE .. 32 AND THE VOTER .. .. 36 siderable body of wireless users PROGRAMMES FROM , whose situation is such ABROAD.. .. 37 that 41 nothing tending to aggravate the interference prob- USEFUL DATA CHARTS: No. 19 (STAGE 3) NEW APPARATUS 43 lem can be tolerated. Obviously, reduction of selectivity DRY 46 CELL H.T. BATTERIES (CONCLUDED). BY R. W. W. SANDERSON can be overcome BROADCAST BREVITIES 48 by adding further tuned circuits, READERS' PROBLEMS .. 51 generally ...... 53 in the form of couplings between high - frequency amplifying valves, but this is an expedient DIODE likely to appeal to the few rather than to the average DETECTION. amateur, T will who is always reluctant to add to the number be interesting to see if the modernised version of his controls. of the two- electrode rectifier -forerunner of all As readers are fully aware, it is not our policy present -day valves -will find a permanent to de- place in cry any innovation that contributes something to the broadcast reception. An article in this week's issue shows ultimate end of perfect broadcast reproduction, even that this method of detection can be applied to the though it more ambitious may be accompanied by its own particular type of receiver with great possibilities, problems and difficulties. not only as regards Accordingly, we welcome the volume, but also as to sensitivity, diode because, properly and that results approaching handled, it will clear one stage perfection are attained only of our receivers from risk of distortion. at the expense of considerable care and some com- plication. The amateur must retain a sense of proportion, and should realise that, for example, a correctly- operated Is it likely to appeal widely to those with less ambitious anode -bend rectifier only begins to manifest its short- requirements? To answer this, we must realise comings that in order when the depth of modulation at the transmit- to obtain distortionless rectification, it may ting station- reaches be necessary to apply a figure rather higher than the a grid polarising voltage suffi- present -day average, and under existing cilently high seriously to reduce conditions its the life of the smaller slight imperfections are hardly likely to become type of valve ; this obvious seems to be one of the gravest dis- to the ear until loud speakers advantages of the are still further improved. system. In view of this, it would If it is decided to hardly appear to be strictly. reduce this polarising voltage to a necessary to include diode detection value something less except in cases where than that required for perfect no expense or trouble is spared results, there still remains to avoid distortion at the very real advantage of each and every stage of the receiver. A IQ

www.americanradiohistory.com ','!i"r"1".41+74.9

WIp@Ilgoo 26 'Void JANUARY 9th, 1929.

Complete Details for the Home Constructor. By F. H. HAYNES.

LITERALLY to attempt the building of a picture re- As stiffness of the panel is an important factor, hard - ceiver with the aid only of a screwdriver and the rolled aluminium sheet of greater thickness than is com- usual wiring requisites might appear unduly opti- monly used for radio purposes is necessary. Being mistic. Nevertheless, this condition has been made the ,Lin. in thickness, it is more difficult to work than the stipulation in the drafting of the following constructional usual hin. aluminium panel. A complete finished panel details. To this end, therefore, it was necessary to create can, therefore, be obtained, of which precise details are certain new components, of which particulars appeared given in an accompanying drawing. Screw heads are in last week's issue.l This has been followed by an avoided on the upper face by tapping blind holes on the enthusiastic response by manufacturers to render avail- underside, a permissible proceeding in view of the liberal able each component part so that the home constructor panel thickness. Aluminium is not an easy metal in is merely called upon to assemble, wire and adjust an which to tap blind holes, and really the home constructor instrument in which nothing has been spared to render it making his own panel might be well advised to use robust, reliable and capable of the best results. Dimen- round- headed nickel -plated screws and nuts, taking the sional drawings of the principal components having been holes right through the panel. No attempt should be given, it is now necessary to present the leading and made to clean up the face of the panel, and a good finish essential data of assembly. may be readily given by producing small scratched circles- at tin. intervals with the aid of a piece of fine "Building a Picture Receiver," page 2, January 2nd, 1929. blue emery paper rotated under the thumb. To protect

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Circuit of the Fultograph picture receiver. Contacts (a) and (b) open together during the passing of the join in the paper under the stylus. The cam operating (a) has a duration of 45 degrees and the cam tor (b) 15 degrees. A 20

www.americanradiohistory.com JANUARY 9th, 1929. Wilpsh§o . 27 W©h-Ild Building a Picture Receiver.- exert an appreciable pull, and as a further measure the the surface from dulling, treatment on both sides with top of the catch may be slightly ground away so that transparent lacquer is desirable. when resting against the plate its lower end already pro- The first step in assembly is that of setting up the trudes into the niche. spindle between the two- recessed screws carried in the In order to finally assemble the clutch it is necessary iron angle brackets, particulars of which have already to secure the cylinder to the spindle with its cams in been given. Oil- retaining holes are taken into these the correct relative position with regard to the catch. screws beyond the conical part to serve as containers for There are two cams, one of brass giving a lift over lubricant. The spindle should run true in its centres 45 degrees of rotation,' and the other of paxolin giving a without. undue friction, while the bracket holding-down lift over 15 degrees. Both cams have their front edges bolts are screwed up as tightly as possible. A " blued " coinciding, so that the pair of light contacts lift together. finish was given to the brackets and screws of the V- shaped ends on these springs are at the same height receiver illustrated here by immersion in hot sand after above the panel as the spindle centres. Correct relation- filing bright and removing all scratch marks, though as a ship between cams and catch is obtained when one spring commercial product these brackets, as well as all iron and reaches the centre of the short cam at the same time as brass parts, other than the spindle and armatures, will the catch engages. no doubt be preferred nickelled. An important dimen- In finally assembling the clutch, treat the parts with

This plan view shows many of the constructional details very clearly. It must not be overlooked that the base of the relay fa Insulated from the panel. sion is the spindle height of 5 clns. centres above the light machine oil and see that the three-pin disc has free panel. movement into the holes on the catch plate. First of all With the clutch components slipped on to the spindle, press the clutch up as tightly as possible, and then very the trigger which is used to arrest rotation once each slightly, to the extent of a few thousandths of an inch revolution may be critically secured in position. Its only, ease back the catch plate and tighten its grub screw. armature should stand vertical when the curved face of Adjust the two fibre frictioning plugs so that the clutch the hardened steel catch frictions against the edge of the is just capable of driving the spindle. catch plate. It is advisable not to drive home the grub Pieces of }in. paxolin carry the cam contacts as well screw on the catch plate too securely at this stage of as those for energising the clutch. Pairs of 8BA round - assembly in order to avoid marking the spindle. Sharp headed screws secure the spring contacts and contact rotation of the spindle between the fingert will reveal brackets, the ends of the screws being filed off flush with whether the catch is suitably set -up, as it should never the underside of the insulating material. Pieces of mica fail to engage, and when once caught there should be an slipped under the insulating pieces before assembly pre- almost imperceptible amount of play. Should the vent contact between the screws and panel. trigger jump the catch as the one is swept quickly past In order to retain the cam -operated contacts in a posi- the other, the tensioning spring may be tightened up to tion for making preliminary adjustments of signal A 2I

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Drilling detai:s of the panel, which is of hard aluminium 7 32in. in thickness. A. 9116M.; 13, 318in. ; C, 5 16in. ; D, 1 4in. ; E, 7'32in. ; underside. L, 1 Sin. M, drilled F, 3 16in. ; G, S32m. H, drilled and tapped 43A. K, drilled and tappet 4B 4 as blind holes on the and tapped 6í3A. N, drilled and tapped 6í3A as blind holes on the underside. Holding down holes are needed at the corners. strength a brake must be provided to hold the spindle. clutch. Its fibre shoe is shaped to fit the contour of the This consists of the stop supplied with the motor mounted clutch so as to produce maximum friction, while the on a tin. brass bracket and engaging on the face of the lever is arranged so as to release with a good snap action. Removal of the spindle permits of fixing the motor 4 BA GRUB 5CCEw by its three screws. It is to IIyz be noted that the motor is spaced away from the panel 4 5TEEL COD 50ACE COO by three fin. brass washers, as the rubber spacers normally supplied with gramophone motors are obviously MA FROM 4d SQUARE unsuitable here. It is an SECTION BCA55 Tu6E easy matter to bend round the speed -regulating arm so as to engage on the pin which is operated from the // top of the panel. Avoid PAT SECTION acute bends, however, in 5* OWING STOP this arm, as it is desirable PIN J 3CA5î COD On 5TYLt)5 that it shall not be excessively springy. A brass fits on to the taper- 1/4 SOLACE BC A5S adaptor ('.OD ing vertical spindle, and the centre of the pinion secured to this shaft must be 5 cros. from the upper surface of Ku r'_ restoring tYriELL l= ELL) the panel. Before the spindle, run the motor and see that this vertical 'Constructional details of the carrier. A short piece of No. 24 platinum wire is used for the tip of the stylus. shaft runs without wobble. A 22

www.americanradiohistory.com JANUARY qua, 1929. Wpdtto 29 .NVoreIl0. Building a Picture Receiver. - spoil the quality of a picture. If not absolutely true, it Tightly mesh the pinions by the play provided in the is better to lock the wheel so that it does not rotate and mounting screws of the motor, taking care to avoid any merely frictions in the screw thread. It should be noted, tendency to bind. A smooth, silent drive should be also, that the sharp edge of the wheel does` not touch the obtained. Washers are, of course, inserted under the bottom of the thread. heads of the screws used for mounting the motor, and in order to obviate the slightest shift caused by leverage Wiring and Adjusting. when winding it is essential that these screws should be Wiring -up can be proceeded with according to the right tight. arrangement adopted in the practical wiring diagram. The relay is conveniently mounted on the front edge Insulation of the input terminals from the panel is proof the panel, being supported on a lin. paxolin base vided by a piece of paxolin on the underside. A ter- and using a pair of screws passing through bushed holes. minating strip is also needed, carrying the three connec- Many possible designs present themselves in the tions to the H.T. and L.T. batteries. A three-wire lead

View showing the finished carrier as well as the setting up of the cams and contacts. making of the carrier which traverses the cylinder. In terminating in a pair of tags and an H.T. plug serves to this instance a simple design was adopted incorporating a connect to the batteries common to the wireless receiver. pair of pulley wheels fitted into the channel provided by Wiring is carried out with No. 20 tinned copper wire and a piece of tin. square brass tube: Both arms are hori- 2 mm. sleeving. A non -inductive wire spool of ioo ohms zontal. It is therefore advisable to proceed by adjusting resistance shunts the trigger winding, and consists of the height of the vertical pillars so that the wheel arm is 6 yards of No. 45 Eureka wire wound on double. A r5- horizontal and then fitting the stylus arm into a slot of volt grid bias battery reposes on the bottom of the box suitable depth. These several parts are soldered to- and is adjusted prior to finally inserting the panel. The gether, cleaned bright and treated with cold transparent box is of in oak or mahogany, and measures internally lacquer. Paxolin side strips insulate the stylus block, 8in. x ióin. x 51in., and the panel is mounted on strong while a pill limits its movement. A light spring, which supports of rin. square wood standing in the corners so need not be adjustable, keeps the stylus in gentle pres- that its top edge is just proud above the box sure against the surface of the cylinder. It is most im- Adjustments are as follows : Time the cylinder to run portant that there should be no possibility of the stylus free at about 52 to 53 revolutions to the minute. arm causing the knife -edged wheel to lift out of the Set the cam contacts so that a good break is provided, thread. This guide wheel must, of course, run per- noting also that the brass cam makes good contact with fectly true, as any tendency to rock from side to side will the spring and picks up connection with cylinder and A 23

www.americanradiohistory.com {e.v.at Ei':W,47M111774é"r4!PMMIrrr/MI

30 JANUARY 9th, 1929.

LIST OF !'ARTS. Baseplate, finished and drilled as shown (Co!Thro es Precision Semi Millimnmeler, 5 mA. scale (Ferranti). Co., Ud. I'roeost Works, Macdonald (toad, IValthamatow, E.17). Carrier with pulleys, knife wheel and stylus (Williams d Moffat, Ltd.). Spindle will& tend brackets and screws (Colinson's Precision Screw Co., Carrier support (Williams & Moffat, ltd.). Ltd., Proroat Works, Macdonald Road, Walthamstow, E.17). Platinum wire, No. 24 S.W.G., if required separately for stylus, tin. Magnetic clutch and pinions complete (Wireless Pictures (19:8), 144., (Baird & Tatlock, Cross Street, Hatton Garden, London, B.C.). 14/16, Regent Street, London, 5.11.1). i'alte holder (Aernionie horizontal type, Jas. Christie d Sons, Ltd., 246, May as detailed (Goodman, 27, Farringdon Street, London, E.C.). West Street, Sheffield). Trigger complete (A. Baker, 89, .Selhurst !toad, South Norwood, London. 2 Terminals, " input" (Belling Lee). S.E.25, or Colinson a Precision Screw Co., Ltd.). Condenser, 0.01 mid. (T.C.C.). Gramophone motor, type 10a, complete with stop and speed regulator. Interaalre transformer, 6 : I ratio. (Forino in plain metal case. The Fitted with extension sleere on spindle, three brass spacers ant pre- Forino Company, 22, Crieklewood Lane, London, N.11'.2). Jerably a modified speed control arm, and winding handle (The 3 Wander plugs, two red, one green. Also two spade connectors, one Garrard Engineering and Manufacturing Co., Ltd., 17, Grafton red, one preen (The Lisenin Wireless Co., la, Edgware Road, London, Street, London, 1V.1.). 11'.2). Cylinder with cams (CoUinson's P.S. Co., Ltd.; Williams d Moffat, Itesistmwe spool. Llit., Ladypool Road, Sparkbrook, Birmingham : Wilkins é Wright, 4 ozs. No. 20 tinned copper wire awl 6 yards of 2 mm. steering. Ltd., Utility Works, Ilolyhead Road, Birmingham). Cabinet, internal dinwnsions, Bin. x 16in. x 5,1i n. in tin. oak or Clutch and cam contacts mounted on kaolin bases (Wilkins d' Wright, mahogany (S. A. Smith, 159, New Kent !toad, London, S.E.). Ltd.). Starch iodide solution (Wireless Pictures (1928), Ud.). On and off switch (irilkins & Wright Type, 11.171). Approximate total cost, £14. Until manufacturing arrangements are further progressed only a limited supply of component parts is available and delay in meeting the requirements Of readers will be inevitable. Notification of other sources of supply have been received yet reference to them here is omitted owing to uncertainty as to the ability to give reasonably early delivery. spindle. Adjust the forward stop of the trigger so that a movement as possible, and see that it has no tendency catch does not engage unnecessarily deep in the plate. to stick, adjusting by altering the tension of the arma- See that its back contact closes just before the limit of ture spring and increasing the gap in front of the poles. movement is reached and does not remain closed, when For rectification use a valve such as the H.L.6io, the catch drops forward against the brass edge of the P.M.6DX, or corresponding valves in other series. With catch plate. Allow the relay armature to have as small a potential of some 15o volts grid bias is adjusted to

The reference letters on the contacts correspond with thos given In the theoretical diagram. A 14

www.americanradiohistory.com JANUARY 9111, 1929. Wapd@EO WollIld 31 Building a Picture Receiver. - not spread. A good grade of paper is known as " Per- bring the milliammeter practically back to zero. Pre- fection," 182Ib. grade (Venerables, Tyler & Co., ceding Ltd.). the picture transmission is a tuning signal which, Spreading of the fine lines of the image is as much by a means of volume control, should give a reading of property of the solution as the paper, and one cannot do not more than 3 milliamps on the meter. During this better than procure solution ready prepared. As an adjustment the break must be on the motor, as the relay will be closed and the trigger out. Too great a reading on the milliammeter will endanger synchronisation, as

Underside view showing the assembly and method of running the leads. the relay may be operated by mush. Having adjusted alternative to the fitting of a clip to the cylinder to hold the receiver to give the correct meter reading, raise the down the paper a trace of Seccotine will secure the switch to " off " and let go the break. On the com- starting edge as well as the flap at the overlap, while by mencement of the preliminary picture signals press down this method .folds in the paper are easily avoided. the switch and the machine will then start and run in A schedule of picture broadcasts will be found on synchrony. another page. It is believed that an early extension of Much care is necessary in the selection of the paper these transmissions is contemplated. and in the making up of the starch iodide solution. An (This picture receiver is available for inspection by absorbent paper is required with a surface that will not readers at the Editorial Offices, 116 -117, Fleet Street, fray, while the lines of the image once recorded must London, E.C'.4.)

.1 Call from Hong -Kong. seven horizontal zones, the most Mr. J. W. Brown (VS6A13), of Kow- TRANSMITTERS' NOTES. northerly, between latitudes 60° and 67° loon, Hong -Kong, begins a series of short - N., being distinguished wave by the figure 1, tests on Saturday next, January and the most southerly (55° to 57° 3201, N.) with the special object of being from tra and receiving stations. by the figure 7. Italy, we understand, heard by amateurs in Great Britain. The QSL's will be sent to any British stations will retain its present call -signs, EA111, tests will continue until Friday, January during the test s. etc. 25th. The wavelength will be 41.8 ° 0 0 metres, and the following schedule Nationality Prefixes. Kenya Colony. ;G.M.T.) will be observed With reference :- to our note on page 702 Mr. Charles F. Fox (FK 1LM) asks us ZZZ de V38AB Test." of our 'ssue for November 21st, we learn to state that his correct Transmission. Listening Period. address is Box 2000 to that Swedish amateur transmitters will 635, Nairobi, Kenya. Owing 2015 2010 to 2029 retain present to a misprint 2030 to 2045 204e, to 2059 their call -signs, but with the box number appeared as " 653 " in 2100 to 2115 2110 to 2129 the addition of a figure after the SM to the R.S.G.B. Annual, and correspondence 2130 to 2143 2149 to 2200 denote the geographical position. Reports For is often delayed by getting into the wrung will be greatly appreciated this purpose Sweden will be divided into box. A 25

www.americanradiohistory.com .. r... .r.

WfiTa@qo ?2 Wald JANUARY 9th, 1929.

A Description of the " Kirkifier," with Special Reference to Large Inputs. By li. L. KIRKE, M.1.R.E. EING largely responsible for the development and positive, of course), have an impedance of the order of 1,) introduction of the distortionless diode (which, r,oóo to 1,50o ohms. incidentally, has been christened the " Kirkifier " I noticed, further, that most of the curves are fairly for want of a better name), I straight over quite a fair sweep feel that a few notes on the " of anode voltage. subject, giving some of my This article, by the originator of the space charge Having got the idea of the own experiences with this type neutralised " diode detector, explains the precautions neutralised space charge diode, of rectifier, will be of consider- that must be taken in order to obtain perfectly dis- I immediately rigged up the able use to readers, particu- tortionless rectification. An interesting new B.B.C. circuit (Fig. i) which, it will long- range, receiver larly in conjunction with the high -quality is also described. be seen, is the same as Fig. 3 recent article in this journal on in the article already men- " The Distortionless Diode," by H. F. Smith. tioned, with the exception that I did not tap down the It may be interesting to describe how this specialised tuning inductance. The quality was excellent, and the rectifier first came into being. sensitivity good compared with a crystal, although poor I had always been interested in the possibility of a compared with other types of valve rectification. linear rectifier of the thermionic variety, as, with such a rectifier, it would be possible to have a permanent and Distortionless Rectification with Deep Modulation. stable arrangement by which certain definite results An investigation into the properties of this type of could be obtained, provided that certain rectifier was then commenced, and it was definite conditions were fulfilled. found that with a positive potential of 24 I was looking up some characteristic volts applied to the grid, the rectifier was curves on valvés in which the anode cur- linear up to about 2 mA. rectified current rent was plotted against anode voltage for with io,000 ohms in the anode. This was various values of grid voltage. I was using an LS5B as a rectifier. Under this actually interested in certain conditions condition it will be seen, that we can work obtaining in a transmitting circuit when, at a normal rectified current of r mA. at the instant of time when the voltage at and get distortionless rectification, even if the anode was low and the voltage at the the modulation is as high as ioo per cent. grid was positive. Reference to a set of maximum ; and at no per cent. modula- curves such as these will show that the tion the peak voltage output from the anode current rises quickly for the first detector will be io volts. Actually, how- few volts applied to the anode when the ever, the peak modulation seldom exceeds grid is positive, and after the anode volt- 70 per cent. to 8o per cent. age has reached a certain value the curve Fig. 1.- Circu it arrange - It was also found that if the value of flattens off. That is to say, for small ment of a rece iver with a positive potential applied to the grid was single valve connected to anode voltages the impedance of the valve function as a dio de rectifier. reduced, then the maximum rectified cur- is low, and for higher anode voltages the rent with linearity was also reduced. The impedance becomes high or normal. For instance, a reason for this is that, for linearity, the positive potential valve whose normal anode impedance is of the order of on the grid must always exceed the maximum positive 20,000 ohms may under certain conditions, when the potential actually applied to the anode. Persons using anode voltage is less than the grid voltage (both being this type of rectifier should be extremely careful of the A 26

www.americanradiohistory.com JANUARY 91h, 1929. WAmIlismo MAO 33 The Diode Rectifier. - were sought. A method more conditions suitable to the use of a under which it is worked for this reason. cathode ray oscillograph would be The rectifier one iu which the was then incorporated in the newest types story, as it were, was written on the oscillograph screen of monitoring and checking apparatus, as for these pur- in the form of a single line, which might be a straight poses it is Preferable that every piece of apparatus is as line, circle, or a sine wave, according to the type of perfect as possible, in order that imperfections in the observation being carried out. This necessitated the apparatus under observation may be clearly distin guished. We wished in this case to have a convenient value of rectified current, so I mA. was chosen as being a value which was easily readable on a o -2 milliammeter, which in turn was a convenient sort of meter to use, the more sensitive types of meter being more expensive, less robust, and, in general, less fit for a maintenance service. Applications of the Linear Rectifier. It was necessary to have some readable rectified current, as a modulation meter was worked off the receiver, and was calibrated in modulation voltage for a certain value of rectified current, i.e., Z mA. None of the above tests as to linearity was done at high frequencies ; and while the actual tests showed that the rectifier was linear, it was quite possible that, under working conditions, the rectifier might not be linear. A further use for the rectifier was found later in test- Fig. 3. -A circuit incorporat:ng ing the linearity of transmitting apparatus -in particular a pentode before the Kirkifier." during the experimental work at 5GB. Here we re- use of some form of known linear rectifier. It was then quired to find out whether the envelope of the high -fre- necessary to carry out experiments on the Kirkifier to quency wave form was strictly proportional under all find out how linear it was, and what were the conditions conditions to the low- frequency modulation applied to necessary to obtain complete linearity. Further, for the transmitter. There are various ways of making this convenient observation of the cathode ray oscillograph, test, some of them including the use of a cathode ray a voltage sweep of the order of several tens of volts was oscillograph. necessary. A method normally employed is to apply the modu- A number of experiments were carried out with the lated high -frequency E.M.F. to one pair of plates of the Kirkifier, and it was found that the most linear result oscillograph, and to apply the modulation frequency to could be obtained by using quite a large positive poten- the other pair of plates. A truncated triangle results, tial applied to the grid of the order of 5o to ioo volts, the straightness of the sides being a measure of the when the output from the Kirkifier could be increased linearity of the apparatus. considerably. The cathode ray oscillograph, under these condi.:Jns, The Question of Harmonics. vas not always entirely satisfactory, and other means A further effect was observed -that it was preferable for this purpose to arrange the coupling between the 15 high-frequency circuits and the rectifier so that, looking OSRAM PENTODE PT 235 back from the rectifier, the condenser - 1äp00 IN ANODE CIRCUIT was always con- 100 V. ON SCREEN nected across the circuit. Therefore, tapping down an 100V.ON ANODE AT 7 m A inductance coil was not quite as satisfactory as using a low L/C value of tuned circuit, or a tapped -down condenser. It is well known that any form of diode rectifier produces harmonics of considerable intensity ; and it would therefore appear from these results to be desirable to provide a low impedance path 'for the harmonic currents. This low L/C ratio is rather inconvenient. The writer has at the moment no suggestions for overcoming the difficulty. Any suggestions from readers will be very welcome.

0 As has been pointed out, the Kirkifier is a device re- -20 -l0 0 quiring power to operate it, and power of rather an GRID VOLTS inconvenient form ; apart from all questions of selectivity, the power has to be supplied from the preceding valve, which must not itself distort in supplying the Fig. 2. -Curve showing the performance of a pentode when de- power to livering an input to a diode rectifier under conditions shown at the rectifier. the top of the diagram. The writer has found that in order to produce i mA. A 27

www.americanradiohistory.com i-}!1 [J,(/, F, -`l. :'IN ivf%'=7A . .

Wilpg@g0 JANUARY gth, 1929. WeDd The Diode Rectifier. - It is still preferable to use a low value of L/C in the of rectified current it is necessary to use a valve of the tuned circuit of the pentode in' order to get a measure L.S.5 type, or, at any rate, having the eqpivalent of selectivity and sufficient by- passing of harmonics. characteristics at a high- tension voltage of the order of A circuit which can be conveniently used for the 18o to be completely safe. Kirkifier is shown in Fig. 3. Attention has been drawn to a very important factor The Pentode as High -frequency Amplifier. in the use of the diode type of rectifier ; it is in no way A further difficulty in connection with the use of the connected to the high- tension supply source, and in con- Kirkifier is that a certain amount of distortion is liable sequence it will be unaffected by reactions due to com- to occur if any reaction is permitted between the anode mon impedance in any such supply source. This is a and grid circuits of the preceding valve. It is therefore considerable advantage where mains units are employed. necessary to have this valve carefully neutralised. For The writer considers this property to be of the utmost : idea should be carried > mA. rectified current the writer normally uses a I I importance, and suggests that the high- frequency transformer, the primary having a one step further, and that the last, or output, stage of neutralising winding and the secondary tuned by a o.00r the circuit should be of the push -pull variety, in which mfd. variable condenser. the audio -frequency currents do not necessarily have to To overcome the necessity of neutralising, some pass through the high- tension supply system, but can be experiments were carried out with the use of a pentode conveniently localised.

J l The general layout of the seven-valve receiver. preceding the Kirkifier. The ordinary screened valve has If a receiver is designed which consists of a distortioii- an insufficient linear power output to work the rectifier, less dike rectifier, one stage of low- frequency amplifica- whereas it was thought that a pentode might just do the tion, and one push -pull power stage, we shall have a trick, and also provide slightly more amplification than receiver which will give excellent quality, and will be was obtained with the ordinary 3- electrode valve. It was practically free from any interaction due to common im- found that the pentode direct coupled (tuned anode) was pedance in the H.T. supply circuits. The rectifier may when normal sensitivity is about 4 times as sensitive as an L.S.5 with a I : I output be preceded by a pentode transformer. A voltage magnification of the order of 5 required, . and this, in turn, may be preceded by an to Io times is thus obtainable from a pentode working ordinary type of screened valve where still greater sensi- into a Kirkifier. tivity is required. experiments have been In practice, some preliminary Grid Battery must Supply Current. carried out, and it would appear that a pentode on ioo volts H.T. works remarkably well. As an 'illustration of the order of sensitivity of the Experiments carried out by Mr. Greenwood on the neutralised space charge diode, plus pentode H.F., using functioning of a pentode with various values of external an ordinary sort of aerial (height about 25 to 3o ft.), it anode impedance, and some experimental work on was possible to obtain a rectified current of s milliam- Kirkifier circuits, showed that the impedance of the pere from 5GB, the receiver being situated in South Kirkifier circuit could be considered as equal to the anode London. resistance of the Kirkifier in parallel with approximately A great disadvantage of the distortionless diode is that 50,00o ohms. Therefore, if we use ro,000 ohms in the the grid polarising battery has to supply quite a con- anode of the Kirkifier the total apparent impedance, siderable current, especially when large inputs, which looked at from the input circuit, will be just over 8,000 automatically require a high grid polarising voltage, are ohms. to be handled ; about 20 mA. at 24 volts is a usual value. A curve in Fig. 2 shows the performance of a pentode If the grid polarising potential is being supplied from a under these conditions. It will be seen that, for an out- mains unit a certain amount of care should be taken in put impedance of io,000 ohms, the pentode is linear the design of the associated filter circuits, as the grid over a range of 6o volts output. current will vary in the process of rectification, i.e , with A 28

www.americanradiohistory.com JANUARY 91h, 1929. WWp®Il@gg Walla 35 The Diode Rectifier. - placed in such a position that the run of the leads in the amplitude of the potential applied to the anode, and each case was as short as possible. This is particularly if there is impedance in the grid circuit some potential necessary in the case of the screens of the screened -grid will be dropped across this impedance, and the potential valves. on the grid varied *during rectification. This may, or Volume control was effected by damping resistances may not, have a bad effect. The writer has been unable across each of the tuned circuits except the last. With to experiment up to the present ; but if the impedance this form of volume control very high quality with no in the grid circuit is different at different frequencies, sideband cut -off can be obtained where signals are very

300 V +

c H.F. TRANSFORMER

01 mfd 10.001 mfd O mfd a O ó C 00005 0'26 mfd O °al ó mid 8Ò6Ò 1 I 500 TURNS L 20000 0 "

0.001 mfd 100000 0 o POT5 0-1-5 mA H.T. - L.T. -

ó G.B. -

G.B. - O.B.-

Fig. 4. -A highly specialised receiver embodying a diode rectifier. The 3 -valve high- frequency amplifier contains two screened -grid valves followed by a pentode or L.S.5. then there will probably be a certain amount of fre- strong and interference small, as in local station work ; quency characteristic distortion, apart from any possible selectivity combined with high sensitivity is obtained form of amplitude distortion due to this reaction. where necessary, with a certain amount of reduction of The writer understands that there will shortly be on the quality due to cutting off sidebands. market electrolytic condensers of high capacity which In practice the receiver was worked in a small van will withstand a working potential of the order of 40 with an aerial of only a few feet high. Rectified cur- volts. These condensers should assist materially in solv- rents of the order of i mA. were easily obtainable at ing the problem of grid polarising potential from the about 40 to 5o miles from 5GB. With at fair aerial mains. excelÍent reception is obtainable from such stations as Langenburg, even in daylight. A Distortionless Receiver. The whole set was run off a 12 -volt 120 a.h. accu- The diagram in Fig. 4 shows a general type of circuit mulator, which supplied current to the filaments, current that the writer would advise for use in connection with to the M -L converter, and polarising current for a a diode rectifier. moving -coil loud speaker which was used for these The receiver shown photographically in the text and particular tests. title illustration was originally developed using a neutral- It has been found that for use in a medium -sized ised L.S.5 preceding a Kirkifier, but is now being room the high- tension voltage can be reduced to about changed to a pentode. 200 or i8o, when valves of considerably lower filament The circuit normally comprises two screened valves consumption than the L.S.5 can be used in most cases, type S.625, one L.S.5 or pentode, one L.S.5B Kirkifier, such, for instance, as the P.M. 256, P.625, or P.X.65o one L.S.5 as first L.F., and two L.S.5s in push -pull as for the power stages, and a P.M.6, D.E.5, or the equiva- output circuit, the output transformer being centre-tapped lent for the first L.F., also for the valve preceding the and its impedance arranged to suit the particular loud Kirkifier. speaker. Each stage, including the screens of the In the receiver just described the inter -valve trans- screened valves, was fed through a resistance from a former between first L.F. and power stage was choke - common H.T. supply source (an M -L converter), suit- capacity coupled, as the particular transformer was able filter condensers being used in each case to provide wound on a Mu -metal core, and no D.C. was permis- a short path to earth. The condensers were actually sible. A 29

www.americanradiohistory.com Mp@Il@gg JANUARY gth, 1929. MTH THZ MICROPHONE &ma as VOTER. Lessons from the U.S. Presidential Election. ITH war clouds already piling up on the British political horizon, our statesmen are fortunate w in having received, as recently as November last, an object lesson in the value of broadcasting and speech- reproduction systems in the education and direction of public opinion on the points at issue. For a period of nearly twelve years the voters of the United States have been surprisingly indifferent to political campaigns. In the presidential elections of 1920 and 1924 the percentage of citizens who went to the poll was extraordinarily low. In 1928, however, nearly forty million votes were cast out of a possible forty - three million. This gratifying increase is attributed almost entirely to the use of broadcasting. From the first day that Mr. Hoover and Governor Smith began their active radio campaign, 'interest in the election became more and more marked. Chain broadcasting was carried out to an unprecedented extent. Governor Smith's final plea, delivered on election eve, was broadcast by both the National and Columbia systems, embracing fifty -eight stations. LOUD SPEAKERS ADDRESS 350,000 PEOPLE. A cwrner of Open -air Listening. Times Square. New York, showing the coil -driven loud speakers election results to a record crowd. On Election Night, November 6th, practically every which announced the U.S. station devoted its entire time to the transmission of elec- loud speakers shown in the photograph. The ampli- tion results. Many people, too excited perhaps to re- fiers were specially installed for the occasion on the main at home with their sets, listened to the results on fifth floor of a neighbouring building, connected by tele- loud speakers in the streets. The biggest open -air graph and telephone with the leading press associa- gathering took place in Times Square, New York, where tions. The election results were dictated over the 350,000 people, jammed in an area of four square microphone, and, during intervals in the announce- blocks (there are twenty -one of these to the mile), lis- ments, gramophone records of popular election songs tened to election announcements on the moving -coil were reproduced.

7 HE AMPLIFYING EQUIPMENT used to operate the loud speakers shown in the upper photograph. Gramophone records were reproduced during intervals in the announcements. A 3o

www.americanradiohistory.com JANUARY 9th, 1929. red,.go 37 WOO plicl R AcBRO

Hi l I(IIl!Illll'' I111 II II lil 111111 .11I IlIs

BARCELONA (Radio Barcelona), Call EAJ1 (344.8 a.m.. Exchange Quotations. 11,80 a.m., Concert metres) ; 1.5 kW. -6.10, Sextet Selections : Paso- J relayed from Hanover (29; metres). In the doble, de Granada Selection from Interval Rosas (Tónio) at 11.55, a.m., Time Signal. 12.10, News. 1.40, Romeo and Juliet (Gounod -Taván ; Bolero (Diaz Exchange Quotations. 2.30, Review of Books. 8.0, ; del puerto ( Alonso) ; Giles) Schottische, La mejor Illustrated Music Talk by Dr. Wills. Heinitz. 3.30, Fantasia and Ballet from Coppélia ( Delibes- Taván). Violin Recital relayed from Bremen (272.7 metres) : French Lesson. Chimes and 8.30, Advanced 9,0, Concerto in E Major (Bach) ; Concerto in D News. Major Weather. 9.5, Exchange Quotations and (Paganini). 4.30, Request Programme. 5.30, Dr. 9.10, Orchestral Concert : Overture, Military Tattoo Carl Krämer, Talk : Social Insurance in Germany. ; La (Raurich) La Marsellesa (Caballero) Habanera, ty. 8.0_ Talk on Boxing. 8.55, Weather Report. 7.0, costurera (Cotó) ; Boston, Pétalos volando (Soler) ; Variety Programme. 9.0, Weather Report, News, Ballet front Sylvia ( Delibes- Alder) ; Overture to Sports Notes, Report on Snow Conditions and Pro- Egmcmt (Beethoven). 10.0, Programme relayed from granune Announcements. 9.30, " Billbrookens auf Madrid, EAJ7. SATURDAY, JANUARY 12th dem Bö -Bu -Ba " -Satire (Eugen Tann). 10.50, North Sea ; 1.5 kW, and Baltic Weather and Report on Ice BERGEN (370.4 metres) -5.30, Programme Conditions. for Children. 8.0, Programme for Girls. 7.0, Orches- tral Concert. 7.20, Organ Recital by Birger Anrep All Times are reduced to Greenwich HILVERSUM (1,071 metres) ; 5 kW. -9.40 a.m., Nordin : Sonata in. G Minor (Lindberg) ; Choral Time Signal and Daily Fantasia on Eja mitt hjärta (Wileen) Three Legends Mean Time and are p.m. Service. 11.40 a.m., Police except Announcements. 11.55 a.m., Trio Music. (Sjögren). 7.50, Topical Talk. 8.0, Georg Dahl, Talk : 1.40, Concert relayed from the Tuchinski Theatre, Amster- Monaco. 830, Orchestral Concert. 9.0, Weather where otherwise stated. Orchestra Dance Music. dam, conducted by Max Talc ; Pierre Palla Report, News and Time Signal 9.15 (Organ). 3.40, Italian Lesson (approx.), Close Down. by Mr. Giovanni 11.0 Rizzi, i. 4.40, French Lesson by Mr. R. Lafont. BERLIN (Königswusterhausen) (1,649 metres) ; 40 kW. Report for Journalists. 5.25, Talk on Czech History. 5.40, Trio Concert. 6.25, German Lesson by Mr. Edgar -12.45 Phototelegraphy Transmission. 1.80, Pro - 6.0, Programme relayed from Prag,ie. 9.25 Pro- Grün. 7.25, Police Announcements.. 7.45, Progranune gramme from Prague. gramme for Children. 2.0, Herr B. K. Graef, Talk : arranged by the Workers' Radio Society : Concert and Elocution. 2.30. Weather Report and Exchange BRUSSELS (508.5 metres) 1.5 kW. -5.0, Programme Talk. 11.15, Close Down. Quotations. 2.40, Talk for Women, by Dr. Elly of Dance Music from the St. Sauveur Palais de Danse. HUIZEN (340.9 Heuss - Knapp. 8.0, Shorthand Lesson. 8.30, Pro- 6.0, Elementary English Lesson. metres) ; 4 kW.- Transmits on 6.25, Intermediate 1,852 metres from 5.40 gramme relayed from Hamburg. 4.30, Legal Talk, by English Lesson. 6.45, Selections for Piano. 7.0, p.m. 12.10, Trio Concert. Dr. A. Richhardt. Peter Leistenschnei.ier, Talk: 2.40, Progranune for Children. 5.10, Programme of 5.0, Gramophone Selections of Dance Music. 7.30; Gramophone Dangers and Safety Measures in the Mining Industry. " Radia- Chronique." 8.15, Gramophone Selections Remrde. 6.20, Talk by M. Gestel. 6.30, Catholic Bulletin. 6.40, English Lesson. 5.30, Elementary Spanish Lesson. 5.55, Alf Due, 8.30, Concert : Symphony No. 5, From the New World 7.10, Lesson in Dressmaking. 7.40, Talk M. Illustrated Talk : Norwegian Folk Songs. 7.0, (Dvorak) ; Violin Concerto (Beethoven) ; Musical by Feber. 8.0, Choral and Instrumental Concert from " Agricultural " Concert : ' Kirmesmusih," (a) Pepita Adaptation of Macbeth (Dupuis) ; Two Elegiac Bois le Duc, including Talk by M. Geffen. Marsch (Neumann), (b) March, Gruss an Kiel (Spohr), Melodies (Grieg) ; Overture to Charlotte Corday (c) Laudjägermarsch (Rixner) ; ' Altenburger Kirmes- (Benoit) Foll,wed by News and Announcements in KALUNDBORG (1,153 metres) ; 7 kW.- Programme walzer ; Zweibelsdorfer Schottisch ; Polka, Der Herr Esperanto. Concert from the also for Copenhagen (337 metres). -8,30 a.m., Morning Amtmann tanzt ; Reading, Der tolle Bomberg ; Palace otel1011.pa1 11.0 (approx.), Down. Gymnastics. 10.0 a.m. Weather Report. 11.0 a.m., Signal Waltz ; Slow Waltz, Old Inhabitant Country Chimes from the Town Hall. BUDAPEST (558.6 metres) ; 20 kW. -4.10, Talk. 11.5 a.m., Orchestral Dance, Den Herrn Posthalter sein Lieblingstanz. Concert from Wivel's Restaurant. 2.0, Programme for from Voxhaus. 4.45 Selection of Gramophone Records. 550, Talk 8.0, Programme for Scouts. 6.30, Readings from the New Book by Children. 2.30, Instrumental Concert : Overture to Raymond (Thomas) ; Waltz, BERLIN (Voxhaus) (484 metres) ; 4 kW. -910 a.m., the Archduke Joseph on the Great War. 7.0, Relay La plus belle (Wald - Market Prices. 9.15 a.m., Weather Report, News and of part of the Opera " Madame Butterfly " (Puccini). teufel) ; Selection from Lucia di Lammermoor (Doni- Time Signal. 10.0 a.m., Programme of Gramophone 8.40, Time Signal, Weather Report and News. 9.0, zetti) Norwegian Dance in A Major (Grieg) ; Sonata Records. 10.30 a.m., Exchange Quotat.ons. 11.55 a.m., Selections of Tzigane Music from the Café Emke. in D Major for Two Violins (Corelli) Waltz from The Time Signal. 12.30, Weather and News. 1.0, Pro- Dollar Princess (Fall) ; Spanish March, Curro Cuchares CRACOW (588 metres) 1.5 kW. Mr. Fuda- ; gramme of Gramophone Records. 2.0, Exchange -4.0, J. (Metallo) Recitations by Aage Brandt ; Selection kowski, Talk : Our Winter Fauna. Quotations, Agricultural Report and Time Signal. 4.25, Mr. J. from Nitouche (Hervé) ; Waltz, Roses of the South : Regula, Talk The Foreign Politics of the Past Week. (Joh. Strauss) ; Orientale (Cui) ; 2430, Franz Winninger, Talk : Dankali-A Native Minuet in E Flat.. 4.55, Dramatic Reading for Children : "The Just -so Major (Mozart) ; Violin Solo, Méditation from Than Tribe of Central Africa. 3.0, Willy Möbus, Talk: Stories Kipling). Theatre Anecdotes by Max " (Rudyard 5.50, Miscellaneous (Massenet) Turkish March from The Ruins of Athens Aviation. 3.30, Grube. Items. 6.10, English Reading by Mr. Jean Stanis- (Beethoven). Kommandant Concert from the Café Vaterland : Waltz, Künst- 5.20, Floridon, Talk : The 4.0, lawski. 8.58, Time Signal from the Astronomical Savannas of Central Africa, lerleben (Strauss) ; Potpourri of Overtures (Engle. 5.50, Weather Report. Observatory. 7.0, Chimes from the Church of Notre 6.0, News and Exchange Quotations. 6.15, Time mann) ; Boston, Antra (Braannse ) ; Selection Dame, News and Announcements. 7.30, Programme Rusticana (Mascagni)Mas Was o Signal. 6.30, Mr. Caja Rude, Talk : Street Silhouettes. n relayed from Warsaw. 9.0, Programme relayed from 7.0, Chimes from the Town (Translateur) ; Waltz Fantasia, Deutscher Hall. 7,2, Reading by träumen Warsaw. 9.30, Concert from a Restaurant. 10.30 Thomas P. Hejle. Radio Liederschatz ; Humoresque, Strauss im Himmel 7.80, Cabaret. In the In- (approx.), Close Down. terval -News. Dance Music (Rösch) ; Es waren zwei Königskinder (Ailbout -Niels) ; 9.45 from the Industri Restaurant. Chimes Advertising Notes in the Interval. 5.40, Theodor von DUBLIN, Call 2RN (319.1 metres) ; 1.5 kW. -L30, 11.0, from the Town Hall. 11,15 (approx.), Close Down. Lerch, Talk : Hunting in Winter 6.5, Dr C. Kassner, Weather Report and Concert of Gramophone Selec- News. Talk : The Householder's Responsibilities in Frosty tions. 7.23, 7.30, Talk. 7.45, Irish Lesson KATTOWITZ (422 metres) ; 10 kW.-3.0, Concert of Weather. 6.30. Prof. Esau, Talk : Introduction to by Seamus O'Duirinne. 8.0, Concert : Overture by Gramophone Selections. 4.0, Music Lesson by Prof. F. the Technique of Short Waves. 7.0, Programme re- the Augmented Station Orchestra ; Soprano Solos by Sachse. 4.25, Children's Letter Box. 4.55, Programme layed from ]Iónigawusterhausen. 8.0, Programme of Josephine Curran ; Ballet front Parysatis (Saint - for Children. 5.50, Announcements. 6.10, Talk by Duets, followed by Weather Report, News, Time SSaens) by the Station Orchestra ; Tenor Solos by P. Mr. K. Zieukiewicz. 7.30, Programme relayed from Signal, Sports Notes and Dance Music from the Hotel Bilsbury.; Orchestral Selections from Mignon (Thomas); Warsaw, 9.0, Weather Report and News. 9.30 Dance Esplanade. 11.30 (approx.), Close Down. Soprano Solos by Josephine Curran ; Pianoforte Music. Solos by Fred Stone ; Light Opera Songs by P. Bils- 1.5 BERN (411 metres) ; kW.---3.0, Orchestral Con- bury ; Orchestral Selections from The Gondoliers KAUNAS (2,000 metres) ; 7 kW-3.30, Musical eert from the Kursaal. 3.30, Humorous Interlude. (Gilbert and Sullivan). 9.30, Light Musical Selections Selections. 3.45, '' Radio 4.0, Announce- 4.0, Orchestral Concert from the Itursaal. 6.29, Time by Cedric May and Company. 10.0, Vocal Duets ments. 5.0, Weather Report and News. 5.30, Agri- Signal and Weather Report. 8.30, Talk on History. by Florence Howley and Thompson Dawson. 10.15, cultural Talk. 6.0, Aviation Report. 6.30. Programme 7.0, Symphony Concert, relayed from Basle (1,010 Selections by the Augmented Station Orchestra. relayed from the National Opera House. metres). 9.0, News and Weather Report. 9.15, 10.30, News, Weather Report and Close Down. Orchestral Concert from the Kursaal. 9.35, Dance LAHTI (1,522.8 metres) ; 35 kW.-4.0, Orchestral Music. 11.0 (approx.), Close Down. FRANKFURT (428.6 metres) ; 4 kW. -2.5, Pro- Selections : Scene orientale (Bird) ; Selection from gramme for Children. 2.55, Hints for the Housewife Carmen (Bizet) ; Winterstürme (Fucik). 4.35, Talk. BRESLAU (322.6 metres) ; 4 kW. -2.45, Review of by Fini Pfannes. 3.35, Orchestral Concert with 4.57, Time Signal and Weather Report. 5.15, Orches- Books, by Martin Darge. 3.15, Thé -dansant Pro- Selections by Maria Pos- Carloforti ; in the Intervals tral Selections : Gallop, Reun (Ganz) ; Norwegian gramme. 4.45, kilns Review of the Week, by Dr. News and Announcements. 5.10, Reading from Bridal March (Grieg) ; Hirtenknaue (Grieg) Minuet Ileinz Hamburger and Hans Baldung. 5.25, Esperanto Doktor Katzenbergers Badereise (Jean Paul), by (Grieg). 5.411, Talk. 6.0, Concert : Orchestral Selec- Talk by Hans Plehn. 5.35, Fritz Seemann, Music O. W. Studtmann. 5.30, The Letter Box. 5,45, tions, (a) Drot og Mars, (Heise). (b) Andante religioso Talk : The Wireless and Operetta. 5.55, Programme Esperanto Lesson by W. Wischhoff. 6.15, Talk on (Henriques), (e) Marche hongroise (Berlioz) ; Vocal relayed from Königswusterhausen. 8.20, Shorthand Industrial Councils by Aired Gürteler. 6.45, Prof. Selections ; Talk by Tati Pekkarinen ; Vocal Selec- Lesson. 6.50, Topical Dialogue by Marianne Bruns. Max Flesch, Talk : Poultry. 7.15, " Die Hausdame " tions ; Talk ; Popular Choral Selections ; Orchestral 7.15, " Das Scheidungssouper "- Operetta in Three -Comedy in Three Acts (Erik Hostrup),followed by Selections. 7.45, News in Finnish and Swedish and Acts (Karl Cvancara). 9.0, News. 9.30, Dance Dance Music from Voxhaus. 11.30 (approx.), Close Close Down. Music. ILO (approx.), Close Down. Down. LANGENBERG (438.8 metres) ; 20 kW.- Programme BR -NN (441.2 metres) 3 kW. -4.30 Programme HAMBURG, Call HA (in Morse) (394.7 metres) ; 4 kW. also for Aix-la- Chapelle (400 metres), Cologne (283 for Children. 4.30, Talk on Music. 4.45, German -9.15 a,m., News. 10.0 a.m., Programme of Gramo- metres) and Münster (250 metres). -12.5, Orchestral News Progranmte: and Melodies. 5.15 Weekly phone Records. 11.10 a.m., Weather Report. 11.15 Concert : Overturn to Halka (Mouiuszko) ; Selections A 31

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JANUARY 91h, 1929. 38 W/bEtd. News, Exchange Quotations and Weather Report. Programmes from Abroad.- 12th. 7.23, Time Signal. 7.30, International Labour Office from The Force of Destiny (Verdi) ; March of the Saturday, JANUARY Report. 7.45, Dramatic Selection from the Studio. ; des Lebens Dwarfs (Moszkowski) Waltz, Freut euch In the Intervals : Review of Art and Literature by ; Suite (Strauss) ; Serenade (Rachmaninoff) Spanish Lucio d'Ambra and Fashion Talk by Mine. Pompadour, Auf (Girardin) ; Liebesspiel (Steck) ; Potpourri, All Times are reduced to Greenwich f Al owed by News. Wiederhören (Weninger). 1.30, Hints for the House- 5 Concert., wife. 2.40, Talk on Wireless, by Arthur Wurbs. Mean Time and are p.m. except STAMBOUL (1,200 metres) kW.-3.33, of Music. 3.5, Talk en the Search for Amundsen, by Major Gran. 4.33, Market Prices. 5.15, Concert Turkish 3.30, Johanna Krause, Talk for Women.: What are where otherwise stated. 7.60, Weather R'oort and "Tim?. Si ;nat. 7.40, Vocal and Concert : Orchestral Selection, we to eat ? 3.55, Line Wallerstein, Talk : German Orchestral Artists on their Travels. 4.20, English Lesson, by Symphony No. 8 (Beethoven) ; Songs ; Duet for Ted Violins (Mozart) ; Minuet (Mozart). 9.0, News Prof. F. Hase. 4.45, Orchestral Concert, relayed from One Act (Carlo de Flavis). 9.0, Review of the Week's : and Down. the Breidenbacher Hof. 5.30, Dr. Sa(mony, Talk Events. News. 9.55, Calendar and Programme Close in 9.53, Ancient Chinese" Art and Culture. 5.50, Lesson Announcements. 10.0 (approx.), Close Down. STUTTGART (379.7 metres) ; 4 kW. -5.0, Time Morse. 6.15, Prof. Schumpeter, Talk : Economics. Talk by Josef 1.5 Programme relayed Signal and Weather Report. 515, 9.40, Prof. Hessen, Talk on Psychology : What do OSLO (481.5 metres) kW.- Wittling,- relayed from Freiburg (577 metres). 5.45, of Carnival by Fredriksstad (434.8 metres), Kamer (555.6 metres). we know of the Soul ? 7.0, Relay the : Mars. metres), (500 metres), and Herr H. Bühler, Talk The Planet 8.15,Talk Meeting at the Gürzenich, Ciloene. 9.0 (approx.), Notodden (411 Porigrand on Book- keeping by Dr. Wolf. 8.45, Time Signal and Sports Notes and Commercial Announcements, Ri»kan (448 metres). -8.0, Programme for Children News, on Sports Notes. 7.15, Concert of Alsatian Music: followed by Orchestral Selections and Dance Music. 8.15, Weather Report and News. 6.30, Talk zwei Blumen geblühet, Amundsen. Time Signal. 7.2, Orchestral Con- Songs (Reysz), (a) Es haben 12.0 Midnight (approx.), Close Down. 7.0, (b) Es steht ein Lind in jenem Tal, (c) Du bist die cert : Overture to The Gipsy Baron (Strauss) ; Soprano 4 kW. Weather liuh' ; Violin Solo, Saite Op. 45 (Est) ; Song, Der LEIPZIG (365.8 metres) ; -2.0, Solo from Die Fledermaus (Strauss) ; Selection from ; Selections from Op. 25 Report and Concert of Gramophone Selections. La Bayadère (Kalman) A Rural Wedding (Söder- Morgenstern (Weckerlin) Minuet ; Sacred : Overture to Ascanio in (Boellmann), (a) Gebet, (b) Gothic 3.30, Orchestral Concert mann) ; Selection from La belle Hélène (Offenbach) ; Sym- Songs for Children (Reysz), (a) Ich bin klein, (b) Ihr Alba (Mozart) ; Andante and Minuet from the Selection from Lilac Time (Schubert) ; Un fête d'été à (c) die Hütte weht der Wind; phony in C Major, No. 88 (Haydn) ; Divertimento ; Hirten erwacht, Ober (Si de) ; Waltz, Acceleration (Strauss) Russian A ; William Violin and Pianoforte Selection, Sonata in Minor la Hongroise (Schubert) Selections from ; ; Mazurka Folk Melodies (Slonoff) Waltz (Bolstad) (Hügel), Tell (Rossini) Dutch Dances (Aulin) Waltz, Overture to Poet and Peasant (Suppé). (Hügel) ; Violin and Pianoforte Selections (Bolstad) (b) Der Traum, (c) Der verschwundene Sphärenklànge (J. Strauss). 4.45, \\ ireless News and 8.30, Weather Report and News. 8.45, Topical Talk, (a) Liebesklage, Talk. 5.2e, Weather Report and Time Signal. 5.30. Dance Music from the Hotel Stern ; followed by Variety Concert of Selections 9.0, Reading. 9.30, Wien - Irogramme relayed from Kbnigswuaterhausen. 6.0, Bristol. 1L0 (approx.), Close Down. from many Nations ; Orchestral Selection, Prof. Georg Witkovsky : Lessing as Dramatist. Berlin ; Jeder einmal in Berlin O Wien, mein liebes Call (1,485.15 ; (Alid) ; 8.30, Dr. Raphahn, Talk : The Sentiment of PARIS (Eiffel Tower), FL metres) Wien (Ziehrer) ; Spanish Christmas Carol Europeanism. 7.0, Variety Prcgramme. 9.0, Labour r, kW. -ß5.0, Talk arranged by the C.T.I. 7.10. Heja nasz ar avaron (Kéler -Béla) ; Russian Street - Market Report, News, Sunday Prcgramme Announce- Weather Report. 7.50, " Le Journal Parlé." Singer (Schulrabe) ; Italian Folk S ng, Danza, Danza ; Song ; " The Heart - ments and Sports Notes. 9.30, Dance Music, relayed PARIS (Petit Parisien) (340.9 metres) 0.5 kW.- American Negro Melodies Volga from the Russian (Avert - from Voxhaus. 8.45, Gramophone Selections, Talk and News. 9.0, Breaker "- Grotesque Sch schenko) Orchestral Selection, Japanese Lantern : (Coates) ; MADRID (Union Radio), Call EAJ7 (434.8 metres) ; Concert Overture to The Merrymakers Dance ; Bonjour Suzon (Delibes) Bird in the Cage; :3 kW. Chimes, Exchange Quotations and Dance Scherzo, The Dryads (Raff). 9.25, News and Announce- -7,0, ; Russian Barrel -Organ Songs; : Le Chasseur Heed osz van (Janos) Music. 8.0, Dr. Zito, Talk : Inventions and Inventors. ments. 9.30, Symphony Concert Orchestral Selection, Turkish Patrol ; Mit keres a teme 8.25, News and Announcements. 9.46, Market Report. maudit (Franck) ; Les Petits Riens (Mozart). 10.0, toben (Arpaa) ; Folk Dance, A moda gallega ; Russian Chimes and Time Signal, followed by Two News, fcllowed by Concert : Ballet from La Glaneuse 10.0, ; -hits ; Bukarest (Kand- ; ; Thistledown Dance Song American Song Musical Plays : (a) " Los Cadetes de la Reina " ((Fourdrain) Lamento (Leo Sachs) ier) ; Montevideo (Murrell) ; One-step, Paris (Padilla) ; (Moyr'n and Luna), (b) " Los Descamisados " Haydn Wood) ; Le, Joyeux gamins (Casadesus). in the Interval at followed by News and Dance Music. (Arniches, Silva and Chueca); PARIS (Radio -Paris), Call CFR (1,750 metres) ; (approx.). News and Announcements. du Midi) (389.8 metres) 8 12.0 Midnight 6 kW.- 12.30, Concert of Gramophone Records : TOW OUSE (Radiophonie 12.30 a.m. (approx.) (Sunday), Close Down. Waltz, Sleepy Town, by the Piccadilly Players I kW.- 12.45, Concert arranged by the Radio Club d'Albret. Market Quotations and News. 8.30. 1MI (549 metres) ; 7 kW. -4.20, Pro- can't give you anything but love, by The Knicker- 8.0, MILAN, Call " The Tales of Hoffmann "-Opera (Offenbach), for Children. 4.45 Agricultural Report and bockers ; Fox -Trot, Hello Montreal, by Ted Lewis gramme from Capitol Theatre. In the Intervals: News. 7.25, Time Signal, W ireless Talk and An- and his Orchestra ; That's my Weakness now, by relayed the ; News Market Quotations. 10.15, North African nouncements. 7.45, E. M. Ciampelli, Talk : Verdi, Ukulele Ike ; Varsity Drag, by Layton and Johnstone and with Pianoforte Illustrations by C. Vidusso. 8.0, Stay out of the South, by the Trix Sisters ; Piano- News. 10.30 (approx.), Close Down. (Mendelssohn) ; Relay of an Opera from the Scala Theatre ; in the forte Solo, The Thirty -Sixth Romance VIENNA (517.2 metres) ; 15 kW.2,15, Photo. ; s from Faust (Gounod) : Pianoforte Intervals : Reacting, by Angelo Sodini News and Scldiei Chorus telegraphy Transmission. 8.0, Orchestral Concert : Industrial Notes. Solo, Romance No. 2 (Schumann) ; Bass Solo, Overture to Das Veilchenmädl (Hellmesberger) Mephistopheles Serenade from Faust (Gounod), by Herzen doch nur eins (Richter) Bizet (1,380 metres) ; 30 kW. -- Programme also Waltz, Zwei MOTALA Kipnis ; La Procession nocturne (Rabaud), Alexandre Fantasia (Urbach) ; Ballet Fantasia for Cornet (Böhme) for Stockholm (454.5 metres), Böden (1,190 metres), by the Symphony Orchestra under the direction of Göteborg (416.5 metres), Malmo (200.9 metres), Divertis ement from Wo die Lerche singt ( Lehár) ; the Composer. In the intervals : News. 2.0, Market Gavotte (Red]) Reich mir die Lippen, du Mädel von). Ostersund (720 metres), Sundsvall (545.6 metres).- Prices and Religious Information. 3.45, Dance for Rhein (Silving) ; Selection from Die Fledermaus 4.0, Concert of Light Music. 5.0, Programme Music by the Joss Ghislery Symphonians. In the Cabaret Programme, relayed from (Strauss) ; Wien in deinen Gärten (Recktenwald); Children. 5.45, : News. Agricultural Report. 6.45, Intervals 8.30, ( Recktenwald) ; Anno dazu- Göteborg. 6.45, Pianoforte Recital, by Olof Wibergh Pianoforte Lesson. 8.0, I.ied vom Ra hauspark Musical Selections. 7.30, ; March, Sangesbrüder Sicilienne (Bach) Minuet in B Flat (Schubert) ; and People of Mada- mal- Potpourri (Morena) Military Talk on the Legends, Customs (Richter). 4.30, Reading of Fairy Tales for the Old Moment musical (Schubert). 7.0, Concert by gascar. Followed by Market Prices and News. 8.15, Band, relayed from Ostersund : March, Treu Deutsch and Young, by Elisabeth Boehmer. 5.0, Chamber Concert arranged by " Le Matin," " Le Médecin Quartet, from the Works of (Teike) Overture (Conradi) It is written in the (Molière- Gounod). In the Inter- Music by the Gottesmann malgré lui " -Opera 41, 1 ; Stars (Fétras) Folk Melodies (arr. Lindström) ; Schumann : String Quartet in A Minor, Op. No. vals : News. (c) Mazurka, Confidence (Capitani) ; Selection (Bauer) ; Songs, (a) Frühlingsnacht, (b) Volksliedchen, Mountain. Song (Peterson -Berger) March (Widor). POSEN (344.8 metres) ; 1.5 kW. -4.15, Talk on Boy Aufträge ; Pianoforte Quintet in E Flat Major, Op. 8.0, Topical Talk. 8.15, News and Weather. 8.45, Scouts. 4.30, English Lesson by Dr. Arend. 4.55, 44. 6.25, Siegfried Trebitsch reads from his own Old Dance Music, by the Möller -Gisslow Orchestra. Programme for Children, relayed from Cracow. 5.50, Works. 7.10, Time Signal and Weather Report. 9.30, Dance Music, by Helge Lindberg and his Orches- Talk. 6.15, Musical Interlude. 6.45, Talk for Women 7.15, " Die Stunde " -Three Musical Plays (Labte) tra. 10.30, Dance Music, by Zöll's Orchestra and by Mme. Sabina Swidzi ska. 7.5, Miscellaneous with Prelude and Epilogue. Followed by Photo- Close Down. Items. 7.30, Programme relayed from Warsaw. telegraphy Transmission. In the Intervals : Theatre and Film Notes. 9.30, ; L5 kW. News in Lithu- MUNICH (535.7 metres) ; 4 kW. -Pr ^gramme relayed Time Signal and News. 9.45, Radio Cabaret. 11.0, VILNA (435 metres) -3.0, by Augsourg (560 metres), Kaiserslautern (277.8 Philips. anian. 3.20. Announcements. 4.35, Programme for Concert arranged by La Maison LO a.m. Kwolek. Concert by metres) and Nuremberg (241.9 metres). -6.0, Mandoline (Sunday), Close Down. Children by Mlle. Marie 4.0. Recital. 6.30, Labour Market Report. 6.0, The Military Orchestra. 4.30, Recitations -by Mme. Letter Box. 6.15, Talk on Agriculture in Bavaria, by PRAGUE (348.9 metres) ; 5 kW.-3.30, Concert : H lene Romer Ochenkowska. 4,35, Concert by Dr. Anton Fehr, Minister of State. 6.30, Alfons von Selection (Fucik) ; Selection from The Czarevitch Military Orchestra. 515, Literary Programme. 5.40, Czibulka, Talk : Stanley, the Explorer and Discoverer. (Lehár) ; Extase (Ganse) ; Indian War Dance Recital of Polish Christmas Songs by Mme. Sopnie 7.0, Humorous Anecdotes, relayed from Nuremberg. (Lumbye) ; On the Sea (Ranzato) ; Selection from Bortkiewicz- Wy;ezynska (Soprano), Mr. Sigismond ; 7.20, Orchestral Concert : Overture to Boccaccio Lakmé (Delibes) ; Waltz, Broadway (Friml) Twilight I-olega (Piano). 8.10, Programme Telayed from (Suppé) ; Waltz, Mein Traum (Waldteufel) ; Pot- in the East (Michell) Ballet de parfums (Pops). Warsaw. 6.35, News and Time Signal. 7.0, Talk by pourri on Opernball (Heuberger) Overture to The 4.30, Educational Talk. 4.40, Technical Talk for Mr. V. Charkiewicz. 7.30, Programme relayed front Gipsy Baron (Joh. Strauss) , Radetzky March (Joh. Workers. 5.0, German Programme, News and Pro- Warsaw. 10.30 (approx.), Close Down. Strauss). 8.10, Victor Hollaender Concert 9.20, gramme for Children. 6.0, ' Orpheus in the Under- Time Signal, News, WARSAW (1,111 metres) ; 10 kW.-4.0, Prof. News. 9.45, Dance Music. 11.0 (approx.), Close Down. world " -Opera (Offenbach). 9.0, by and Popular Music from the Hotel Rosenhreier. Sikorski, Talk : French Music. 4.25, Talk Dr. NAPLES, Call INA (333.3 metres) ; 1.5 kW. -4.0, Hemel. 4.55, Programme for Children. 5.50, Mis- Orchestral Concert : The Brandenburg Concerto ROME, Call 1RO (447.8 metres) ; 3 kW.-4,30, cellaneous Items. 6.10, " Radio -Chronique " by Dr. (Bach) Symphony in C Major (Mozart) ; The Sieg- Vocal and Instrumental Concert : Sonata in G Major M. Stepowski. 8.58, Time Signal. 7.0, News. 7.30, fried Idyll (Wagner) ; Symphonic Poem, La Pro- (Porpora) ; Mezzo -Soprano Solos, (a) Le lune blanche " Madame Pompadour "- Operetta in Three Acts (Rachmaninoff) ; Bass cession nocturne (Rabaud) ; Symphony from Semi- )Marta Nervi), (b) Destiny (Fall). 9.0, Aviation and Weather Report. 9.5, News ramide (Rossini). 4.30, Time Signal. 485, Palk by Solos, (a) Air fr m The Magic Flute (Mozart), (b) Announcements, Police Information and Sports Notes. R. Lotto. 7.30, Wireless Notes. 7.40, Announcements. Selection from La Tuive (Halévy) ; Violin Solos 9.:.0, Dance Music from the Oaza Restaurant. 10.80 7.46, News and Harbour Notes. 8.0, Time Signal. (Dvorak), (a) Humoresque, (b) Slavonic Dance; (approx.), Close Down. 8.2, Variety Concert : Orchestral Selection, Overture Mezzo- Soprano Solos, (a) Air from Sm gorotch'ce ; 1 kW.-6.O, Chimes from the to Banditenstrei_-he (Supp5) ; " Una partita a Scacchi," (Rimsky- Korsakoff), (b) Air from L'Amico Fritz ZURICH (583 metres) Fable in Verse (Scaturchio) Orchestral Selections, (Mascagni) ; Bass Solos, (a) Air from Simon Boo - Zurich Churches. 6.15, Time Signal and Weather (a) di Cairo. (Manenfe), (b) Scena zingaresca canegra .(Verdi) (b) Air from Faust (Gounod). 5.30, Report 6.17, Concert by the Orfeo Mandoline and Ricordo Programme relayci front ( Marsente), (r) Misicdite (Manno), (d) Serena ta Wireless Talk by Mr. Cesi, 5.40, Lesson in Morse Guitar Orchestras. 7.0, Report and News. . amorosa (Malmo) ; " Il nome della Diva," Comedy tu by Mr. Crei. 8.50, Announcements, Sports Notes, Vienna. 9.0, Weather A 32

www.americanradiohistory.com ,JHLV f,Lfl, G`/ii cIlcRC tJHLCY 7929. W l 39 Programmes from Abroad Station Trio. 5.30 (approx.), Relay of Church Service - SUNDAY, JANUARY 13th. (,n 1,852 metres) and. Sermon from the Ned. Herv. ALGIERS, Call PTT (353 metres) ; 1 kW.-12.30, Church at Oosterend. Preacher :. Doctor H. by Orches- Concert of Instrumental Musk the Station Gisutter. Organist : G. Froentles. 7.10, Talk. tra : Prelude and Allegro (Pugnani -Kreisler), rendered 10.25, Epilogue by the Choir, conducted by Mr. by M. A. Gonzales. All Times are reduced to Greenwich Jos. H. Pickkers. 10.40 ( approx.), Close Down. (344.8 BARCELONA (Radio Barcelona), Call EAJ1 Mean Time and are p.m. except KALUND3ORG (1,153 metres) ; 7 kW.- Programme metres) ; 1.5 kW. -1L0 a.m., Relay of Cathedral also for Copenhagen (337 metres). 9.0 a.m., Divine Chimes. 11.5 a.m., Weather Conditions and Forecast where otherwise stated. Service Relay and Address from a Copenhagen Chu,ch. for Spain and Europe, followed by Aviation Notes and 10.30 a.m. to 10.40 a.m. (Kalundborg only), Weather Route Conditions. 1.30, Musical Programme by the Conditions and Forecast from the Copenhagen Meteoro- Iberia Trio ; in the intervals, Gramophone Music. logical Institute. 5.50 (Kalundborg only), Weather Signal, ment of M. Léon Leroy. 6.30, Music by the Staion 2.45 to 5.30, No Transmission. 5.30, Opening Trio. 7.30, Le Journal Parlé de Radio Belgique. Conditions and Forecast from the Copenhagen followed by Relay of Part of an Opera from the Gran Meteorological Institute. 6.0, Press News and Infor- Quota- 8.15, Concert by the Station Orchestra. 10.15, Late Teatro del Lice, ; in the Interval, Exchange News Bulletin and Press Review. 11.0 (approx.), mation. 8.15, Time Signal. 6.30, Talk. 7.0, Chimes tions and Market Reports. 8.0 to 8.20, Lecture Close Down. Relay from Copenhagen Town Hall. 7.5, Musical arranged by the Catalonian Institute of Agriculture Programme. 9.0, Concert of Folk Music from Many at San Isidro. 8.20, Concert of Popular Music by the BUDAPEST (558.6 metres) ,_ 20 kW. -8.0 a.m., Lands, rendered by the Station Orchestra, conducted Station Orchestra. 8.40, Sports Chronicle. 9.0 General News Bulletin and Notes for Women. 9.3 by Launy Grondahl. Fantasia on Russian Gipsy (approx.), Close Down. a.m., Relay of Sacred Service with Sermon. 3.15, Songs (N. Artemiev). 10.0 (approx.), Programme of Wireless Educational Programme of Readings, Talks Dance Music by the Palace Hotel Orchestra, conducted BERGEN (370.4 metres) ; 1.5 kW. -9.30 a.m., Divine by Teddy Petersen. In the interval at 11.0, Relay and and Musical Selections. 5.31, Three O is -act Comedies Service Relay. 11.30 a.m. Weather Report of Hungarian Life with Incidental Tzigane Music. of Chimes from Copenhagen Town Hall. U.30 Forecast and News Bulletin. 7.0, Orchestral Concert. (approx.), Close Down. 7.50, Topical 8.0, Trio (Arensky) for Violin, Talk. COLOGNE (283 metres) ; 4 kW.- Programme also for 'Cello and Piano, by Herrn Schuster and Kurt Müller metres), (468.8 metres) KATrOWITZ (423 metres) 10 kW.-9.15 a.m., and Mrs. Signe Bonneire. 9.0, Weather Report and Aix-la- Chapelle (400 Langenberg Minster (2.50 metres). -6.45 a.m., in re Relay of Church Service. 10.56 a.m., Time Signal. Forecast, Late News Bulletin and Time Signal. 9.15, Dr. Review by 11.0 &m., Weather Report and Forecast. 1 :15 a.m., Programme Dance Music. Close Defence by Ludwig Bach. 7.23 a.m., of 1L0 (approx.), Alfred Dormanns of the Week s Programmes in Concert of Popular Music rendered by the Station Down. Esperanto. Esperanto Language Lesson by Quartet. 1.0, Talk. 1.20 and L40, Two Talks for and7.30 a.m., Farmers. Alfred Dormanns. Chimes Relay. 2.0, Weather Conditions and Forecast. (Kdnigswusterhausen) (1,849 metres) ; 40 kW. 8.0 a.m., Church BERLIN 8.5 a.m., Evangelical Festival of Religious Music 2.15, Relay of Symphony Concert by the Warsaw -7.55 a.m., Chimes Relay from Potsdam Garrison Sermon. Philharmonic Orchestra, conducted by B. Szulc; Church. Musical Recital with Address, with Choral and Instrumental Selections and 8.0 a.m., 10.0 a.m., Talk by Fritz Worm on the German Lan- Concerto for Violin in G Minor (Bruch), rendered relayed from Voxhaus, followed by Berlin Cathedral by A. Kontorowicz (Violinist) and the Orchestra. Chimes. Concert, relayed from guage. 11.35 a.m., Agricultural Talk. 12.0 Notify 10.30 a.m., Orchestral Orchestral Concert. 1.30, Talk by Arnold Stecher on 6.0, Miscellaneous Announcements. 6.20, A Humorous Voxhaus. 12.45, Experimental Picture Transmission. Concert. Programme by Professor St. Ligon. 6.58, Time L30 Three Agricultural Talks, frqm Voxhaus. Wireless Literature. 3.80, Afternoon 5.0, Signal. to 2.25, Talk. (approx.), Sports Notes. 8.0, " The Barber 7.30, Evening Concert relayed from Warsaw. 2.30, Programme of Fairy Tales from Voxhaus. 3.0. 8.45 9.0, Weather Conditions and Forecast, Press Bulletin Talk. Programme. Talk. 8.0 of Bagdad," Opéra- comique in Two Acts by Peter 3.30, Musical 5.0, Cornelius, followed by Late News and Announce- and Sports Results and Notes. 9.30, Dance Music ( approx.), Talk. 7.0, Musical Selections, followed by Programme. 10.30 (approx.), Close Down. News and Announcements. 9.30, Dance Music Pro- ments, Sports Notes and Concert. 11.0 ( approx.), gramme. 11.39 (approx.), Close Down. Close Down. KAUNAS (2,030 metres) ; 7 kW. -2.30, Programme CORK, Call BCE (400 metres) ; 1.5 kW. -830, for Children. 3.0, Selections for Young People. BEILIN (Voxhaus) (484 metres) ; 4 kW. 7.55 a.m. ; Organ 3.30, Talk on Health by Doctor Jurgelionis. 4.0. Chimes, relayed from Potsdam Garrison Church. Concert of Vocal and Instrumental Music Recital relayed from St. Fin Barre's Cathedral, Cork. Talk by J. Ardickas : Economics and Daily Life. 8.0 a.m., Morning Festival of Sacred Music with Choral 4.55, Weather Conditions and Forecast and Press and Selections and Sermon, followed by Organist, T. J. Home, Mus. Bac. A.R.C.O. 11.0, Instrumental National Anthem and Weather Report and Forecast. News Bulletin. 5.0, News and Announcements in Relay of Chimes from Berlin Cathedral. 10.30 a.m. the Polish and Lithuanian Languages. (approx.), Morning Concert. 1.0, Elementary Instruc- 1L1á (approx.), Close Down. tion in Morse by Hans W. Priwin. L30 to 2.25, Programme of Talks for Agriculturists. 1.30_ Practical CRACOW (566 metres) ; 1.5 kW. -9.15 a.m. to 10.45 KONIGSBERG (303 metres) ; 4 kW. -Pt ^gramme Advice to the Farmer. L45, A Retrospective Glance a.m., Morning Service Relay from a Cathedral. a0.66 relayed by Danzig (272.7 metres). -8.0 a.m. (Königs- of the a.m., Fanfare relayed from the Church of Notre Dame, berg only), Sacred Festival with Choral and Instru- at the Market Prices and Weather Conditions and Week. L55, Lecture on Farm Topics. 2.30, Pro- followed by Time Signal and Weather Conditions mental Music, Solo Items and Sermon. 10.0 a.m. gramme of Fairy Stories for Children. 3.0, Talk. Forecast. 11.10 a.m., Concert of Orchestral Music (Königsberg only), Weather Report and Forecast. 3.30, Musical Programme. 6.0, Talk. 6.30, Talk. relayed from the Warsaw Philharmonic Hall. 1.0 11.55 a.m., The Na ten International Time Signal 7.0 (approx.), Musical or Dramatic Programme, and 1.20, Agricultural Talks. 1.43, La Chronique followed by Weather Conditions and Forecast. 3.15, followed by Meteorological Report, Late News and Agricole by Dr. St. Wasniewski. 2.0, Weather Con- Concert of Orchestral Music. 7.0, Light Musical Announcements and Sports Notes. 9.30, Dance Music ditions and Forecast. 2.15. Relay of Concert of Orches- Programme. 8.0, "'The Toreador "- Operetta by Programme. 1L30 (approx.), Close Down. tral Music by the Warsaw Philharmonic Society. Adolf Adam. German Translation by René Schickele 6.58, Tune Signal from the Astronomical Observatory. and Franz Rumpel. Produced by Kurt Lessing and 7.0, Fanfare Relay from the Church of Notre Danse, conducted by Erich Seidler. 9.15, News Bulletin BERN (411 metres) ; 1.5 kW. -9.30 a.m. to 10.30 a.m., followed by Sports Notes. 7.30, Evening Concert and Sports News. 9.30, Dance Music Programme Religious Address. 120 Noon, Time Signal and arrangea by the Students of the Drum and Mandoline 11.0 (approx.), Close Down. NVeather Report and Forecast. 12.5, Musical Pro- Circle conducted by M. Kostecki with the assistance gramme. Richard Flury Festival, relayed from 2.0, of Mlle Molislasse Dolega -Bursa (Singer) and Mme. Mela LAHTI (1.522.8 metres) ; 35 kW.- Programme also the Saalbau Grosser Saal, Solothurn : Artistes - Sacewicz (Pianist), Chant sans paroles (Tchaikovsky). for Helsingfors (375 metres).7.0 a.m., Divine Ser- Berthe de Vigier (S rprano), Din:, Ghialberti.(Piano) from vice Press by 9.0, Late News and Announcements Warsaw. Relay. 9.50 a.m., News and Announce- and the Berne Municipal Orchestra, conducted 9.30, Concert relayed from the Pavillon Restaurant. ments. 10.5 a.m., Musical Programme. 10.59 a.m., ; for Richard Flury The Death of Sappho, Soprano 10.30 (approx.), Close Down. Meteorological Report and Time Signal. 3.0, Pro- and Orchestra, First Performance. 6.29, Time Signal gramme by the Station Orchestra, Conductor, Erkki and Weather Report and Forecast. 6.30, Reading or Linko. Talk. Time and Musical Selections. Sports Notes, DUBLIN, Call 2RN (319.1 metres) 1.5 kW.-8.30, 3.50, 4.57, Signal Meteoro- Talk. 7.0, 8.45, Programme relayed from COLL Concert of Vocal logical Report. 6.20, Musical Programme. 7.10, Late News Bulletin and Weather Report and Forecast. and Violoncello Solos by I. Concert of Popular Music by the Wireless Orchestra, Close Down. Instrumental Music. 9.0, Concert Programme. 9.40 (approx.), Walters. 11.0, National Ant.iem and Meteorological conducted by Erkki Linko. Die Sonnenuntergang Report. 1L1.ó (approx.), Close Down. (Olson). 7.45, News and Announcements in Finnish. B1ZIERS (158 metres) ; 0.6 kW. -.6.0, Talk on Agri- 8.0, News and Announcements in Swedish. 8.30 culture, followed by a Concert. 8.30, General News HAMBURG. Call KA (in Morse) (394.7 metres) ; 4 (approx.), Close Down. Bulletin and Sports Notes. 8.45, Musical Programme, kW. Programme relayed by Bremen (272.7 metres), arranged by the Maison Relin -Minoles at BPziers ; Hanover (-297 metres), and Kiel (254.2 metres). - LANGENBERG (468.8 metres) ; 20 kW.-Programme Pathé -Art Gramophone Selections. 10.30 ( approx.), 7.25 a.m., Time Signal. 7.30 a.m., Weather Report also for Aix-la- Chapelle (400 metres), Cologne (283 CI ose Down. and Conditions, followed by News and Announce- metres) and Munster (250 metres). -8.45 a.m., Self - ments. 7.50 a.m. (approx.), Talk on Contemporary Defence Lesson, by Dr. Ludwig Bach. 7.20 a.m., BRESLAV (322.6 metres) ; 4 kW.-Programme re- Economic Questions. 8.0 a.m., Legal Review of the Survey in Esperanto of the Programmes of the Week, layed by Gleiwitz (328.7 metres). -8.15 a.m., Relay of Week. 8.15 a.m., Morning Service. 10.0 a.m., by Alfred Dormanns. 7.30 a.m. to 7.55 a.m., Esperanto Chimes from Christ Church. 1.0, Wir..,es; Gue;;ing Talk. 1L55 a.m., The International Time Signal Lesson, by Alfred Dormanns. 8.0 a.m., Church Chimes Competition. 1.35, Hints for Chess Players by Adolf from Neuen. 12.5 (for Hamburg and Kiel), Sunday Relay. 8.5 a.m., Evangelical Recital of Sacred Music Kramer. 2.0, Programme of Fairy Tales for Children. Concert. 12.5 (for Bremen), Concert by the Station with Sermon in the Interval. 10.0 a.m., Lecture on 2.30, Talk for Farmers. 2.55, Musical Selections. 8.45, Orchestra. 12.6 (for Hanover), Selections of Gramo- the German Language by Fritz Worm. 12.0 Noon, (approx.), Talk. 4.10, Tea -Time Concert. 9.0, Late phone Music. 1.0, Entertainment for Children. Concert of Sacred Music, relayed from the Reinolde- News Bulletin. 9,30, Dance Music Programme. 11.0 10.50 (for Hamburg, Bremen and Kiel), Weather kirche, Dortmund. 1.30, Wireless Literary Talk. (approx.), Close Down. Conditions and Forecast for the North Sea and Baltic. 3.30, Afternoon Concert. 6.45 (approx.), Sports Notes. 11.0 (approx.), Close Down. 8.0, Late News and Announcements. 11.0 (approx.), BRÜNN (441.2 metres) ; 3 kW. -3.30, Orchestra' Close Down. Concert. 4.30, Relay from Prague. Programme for HILVERSUM (1,071 metres) ; 5 k\\'.-12.10, Concert Workers. 5.0, News and Musical Recital for German by the Station Trio. 1.40, Musical Programme. LEIPZIG (365.8 metres) ; 4 kW.-Programme relayed Listeners. 5.39, Talk on Sport relayed from Prague. Recital of Pianoforte Selections rendered by Aglaia by Dresden (275.2 metres).-7.80 a.m., Organ Music 8.0, Concert of Orchestral Music. 9.20, Relay of Dance von Zech. 7.40, Time Signal. 7.42, General News Recital. 8.0 a.m., Morning Musical Programme. Music. 10.30 (approx.), Close Down. Bulletin, 7.55. Musical Programme. 10.40 (approx.), 10.0 a.m., Talk. 10.30 a.m., Talk. 11.0 a.m., Musical Close Down. Selections. 12.0 Noon, Time Signal. 12.2, Agricul- BRUSSELS (508.5 metres) ; 1.5 kW. -5.0, Concert tural Talk. 12.30, Veterinary Talk. 1.0, Review'of the Programme by the Orchestra of the Armenonville Tea HUTZEN (340.9 metres) ; 4 kW.-Transmits from Foreign Press and Foreign Policy. 2.0 ( approx.), Room, Brussels. 6.0, Children's Programme arranged 5.10 on 1,852 metres. --8,5 a.m., Church Service. Gramophone Music. 3.0, Literary or Dramatic Pro- by the Brussels Children's Theatre under the manage. 9.20 a.m., Divine Relay. 12.10, Programme by the gramme. 4.0, Musical Selections. 5.30, Talk. 6,0,

A 33

www.americanradiohistory.com f.1.Vt'.9RY 9th, 1929. 40 WWllcil STUTTGART (379.7 metres) ; 4 kW.- Programme Programmes from Abroad.- - Sunday, JANUARY 13th. relayed by Freiburg (577 metres). 11.0 a.m., Concert Talk. 8.80, Concert. 8.0, Scenes from " Miss Sara of Popular Orchestral Music, followed by Latest Sampson," by Gotthold Ephraim Lessing, produced Gramophone Records. 1.0 Programme for Children. by Hans Peter Schmiedel. 9.15 (approx.), Sports 2.0, Talk or Reading. 2.30 Concert. 5.0, Time Notes and Press Information and News, followed by All Times are reduced to Greenwich Signal and Sports Results. 7.ó, Musical or Dramatic Dance Music Programme, relayed from Berlin. 11.30 Programme, followed by Late News Bulletin and (approx.), Close Down. Mean Time and are p.m. except Sports News. 10.30 (approx.), Clase Down.

LYONS (Radio Lyon) (291 metres) ; 1.5 kW.-7.30. where otherwise stated. TALLINN (408 metres) ; 2.2 kW. -8,0 a.m., Relay The Radio Lyon " Journal Parlé," consisting of News of Divine Service. 12.30, Programme of Orchestral Bulletin, Press Review, Theatre Notes and Announce- Music. 4.45, News Bulletin from the Press. 5.0, ments. 8.0, Concert of Light Music with the colla- Evening Concert. 5.20, Talk. 6.0, Concert of boration of Madame Ducharne (Pianist), M. Camand PARIS (Petit Parisien) (340.9 metres) ; 0.5 kW.- Instrumental and Vocal Music. 9.0 (approx.), Close (Vio.inist) and M. Testanière ('Cellist): Menuet des 8.45, Latest Gramophone Selections. 8.50, Talk. Down. Mousquetaires (Simon). 10.0 ( approx.), Close Down. 8.55, News Bulletin from the Press. 9.0, Concert of Orchestral Music with Soloists. 9.26, News Bulletin. TOULOUSE (Radiophonie du Midi) (389.6 metres) 9.30, Half an Hour of Symphony Music conducted by 8 kW.- 12.45, Concert Programme. 1.0, Time Signal MADRID (Union Radio), Call EAJ7 (434.8 metres) ; by EAJ22 Professor Estyle of the Paris Conservatoire : Adagio L9, Concert (continued). L45, News and Announce- 1.5 kW.-Programme relayed Salamanca, for Violin and Orchestra (Mozart), rendered by M. ments supplied by Le Télégramme, I'Express and Le (405 metres). -2.0, Chimes Relay and Time Signal. Late Concert, with Inter- Bellanger, Soloist of the Colonne Concerts. 10.0, Midi Socialiste. 8.0, Stock Exchange Notes and Cereal 2.5, Orchestral and Instrumental News Bulletin. Concert of Orchestral Music. Prices from Paris supplied by l'Agence Fournier. lude by Luis Medina. 3.30 to 7.0, No Transmission. 10.15, Programme. Talk and 11.0 (approx.), Close Down. 8.15, News and Announcements supplied by the 7.0, Chimes. 7.5, Musical 8.0, Parisian Press. 8.30, Orchestral Concert. 9.0, Reading : Famous Journeys -Extracts from t be ' Concert arranged by ' L'Association des Comuier- 1 Travels." 8.30 PARIS (Radio Paris), Call CFR (1,750 metres) ; 6 most interesting Narratives of Great cants Radio- Electriciens du Midi." The Warblings of to 10.0, No Transmission. 10.0, Chimes and Tinte kW. -8.0 a.m., General News Bulletin and Review of the Press. 8.30 a.m., Daily Lesson in Physical Blackbirds, Canaries, Finches, Nightingales and Signal. 10.5, Musical Programme. 12.0 Midnight, Warbles-s. In the Interval at 9.0, Time Signal. 10.15, Relay of Chimes, followed by Programme of Dance Culture. 12:0 Noon, Sermon followed by Sacred the Festival of Instrumental and Vocal Music. 12.30, North African News and Late News and Announce- Music by the Palermo Orchestra, relayed from ments. 10.30 (approx.), Close Down. Alkazar. 12.30 a.m. (approx.) (Monday), Close Down. News Bulletin. 12.45, Concert by the Albert Locatelli Orchestra with interlude by Bilboquet. 4.30, Pro- gramme of Gramophone Selections arranged by VIENNA (517.2 metres) ; 15 kW.- Programme re- MILAN, litI (549 metres) ; 7 kW.-9.0 a.m., Opening layed by metres), (294.1 metr s), " L'Industrie Musicale." In the interval : News and Graz (357.1 Innsbruck Signal and Lesson in English. 9.30 a.m. to 10.30 a.m. Klagenfurt (272.7 metres), and Linz (254.2 metres). - Music, Instru- Announcements. 6.30, Agricultural Report. 6.45, (approx.), Concert of Sacred Vocal and Gramophone Music. 7.30, Press News and Announce- 9.20 a.m., Choral Programme rendered by the Vienna mental Programme. 11.80 a.m., Time Signal. Boys' Choir under Professor Hans Müller. 10.0 a.m., ments. 7.45, Radio Paris Circus : " A Model Farm " : 1'1.35 a.m., Musical Programme by the Station Quartet. a Scene of Burlesque rendered by the Entire Troupe, Concert of Instrumental Music by the Vienna Sym- of the Elementary 12.1, Vocal Recital by Scholars Messieurs Cordial and Macaron. 8.15, Concert Pro- phony Orchestra and Soloists. 2.30, Experimental Schools : Traditional Italian Songs (Oddone). 8.5, Picture 3.0, Concert of Orchestral gramme. In the Intervals : News Bulletin and Transmission. Musical Selections. 4.15, Programme from the Fia - Evening Press Review followed by Announcements. Music. 5.20, " On Winter and the Ice," Programme of to schetteria Toscana by the Tzigane Orchestra. 5.0 10.30 (approx -), Close Down. Recitations and Music rendered by Margarethe 6.55, No Transmission. 8.55, Opening Signal. 7.0, Witzmann and Franz Horch (Elocutionists) and the Press Notes. 7.15, History Talk. 7.25, Sports Notes. Viennese Concert Orchestra conducted by Max ; 1.5 10.46 7.30, Time Signal. 7.85, Relay of an Opera ; in the POSEN (344.8 metres) kW. --9.15 a.m. to Greiger. 8.55, Time Signal, Weather Conditions and interval: Sports Notes, News and Announcements. a.m., Relay of Divine Service. 11.0 a.m., Tinte Signal. Forecast. 7.5, Dramatic Programme followed by 10.30 (approx.), Close Down. 11.15 a.m. and 11.35 a.m., Two Agricultural Talks. Dance Music Programme and Experimental Picture 2.15, Concert of Symphony Music relayed from Warsaw. Transmission. 10.30 (approx.), Close Down. by the MOTALA (1,380 metres) ; 30 kW.- Programme also 4.30 (approx.), Talk. 6.0, Programme arranged for Stockholm (454.5 metres), Boden (1,190 metres), Catholic Polish Youth Association. 6.20, Talk re- VILNA (435 metres) ; 1.5 kW. -9.15 a.m. to 10.45 Göteborg (416.5 metres), Malmö ('260.9 metres), layed from Warsaw. 7.5, Programme of Miscellaneous a.m., Relay of Morning Service from a Cathedral. metres) and (545.6 metres). Items. 7.30, Concert of Baritone Songs by Brahms 10.56 a.m. to 4.3D, Relay of Warsaw Programme. Ostersund (720 Sundsvall - Sigismmid Sab- 10.0 a.m., Relay of a Religious Service from a Church and Wieniawsky rendered by Herr 10.58 a.m., Thne Signal followed by Fanfare from the for Children. lonsky of Berlin. 9.0, Time Signal. 9.5, News and Church of Notre Dame at OraWOW. 11.5 a.m., Aviation in 8.oekholm. 4.0, Entertainment Mr. 4.55, Relay of Chimes from Stockholm Town Hall. Announcements. 9.15, Lesson in Dancing by Notes and Weather Forecast and Report. 1L10 a.m., 5.0, Relay of Church Service. 6.15, Relay of Play or Starski. 9.40, Programme of Dance Music. 11.0 Symphony Concert by the Warsaw Philharmonic Literary Programme. 7.45, Programme of Choral (approx.), Close Down. Orchestra. 1.0 to 2.0, Three Talks for Farmers. 2.15, Selections. 8.15, News Bulletin and Weather Report Concert of Symphony Music. 4.30 (approx.), Talle and Forecast. 10.0 (approx.), Close Down. PRAGUE (348.9 metres); 5 kW.--8.0 a.m., Concert of in the Lithuanian Language. 5.0, Gramophone Sacred Music. 9.0 a.m., Talk. 3.30, Concert Pro- Selections. 5.20, Programme for Children. 5.45, gramme. 4.30, Programme for Workers. 6.0, Pro- Programme of Zither Music by Professor Witold MUNICH (535.7 metres) ; 4 kW.-Programme relayed Music. Jodko. 6.0 (approx.), Humorous Programme. 6.30. by metres), Kaiserslautern (277.8 gramme for German Listeners, News and Augsbarg (566 5.30, Sports Talk. 6.0, Orchestral Concert of Popular Selections of Zither Music by Professor Witold Jodko. metres) and Nuremberg (241.9 metres). -10.0 a.m. 8.50 (approx.), Time Signal. 7.0 to 10.30, Programme Munich. Selections. 9.0, Time Signal and Late News and Chimes Relay from the Town Hall at 1010 Dance Music. 10.30 relayed from Warsaw. 7.0, " Divertissements in- Relay of the Bavarian Wireless Weather Chart. Announcements followed by a.m., (approx.), Close Down. tellectuels." 7.30, Popular Concert : Aria from the 10.26 a.m., Time Signal and Meteorological Report. Opera " Halka " (St. Moniuszko), sung by M. Grusz- 5.20, Song Recital by Irma Drummer ; Richard Aviation 2 kW. -12.30 to cynski (Tenor) of the Warsaw Opera. 9.0, Staab at the Piano. 7.0 (approx.), Concert Pro- RABAT, Call PTT (414 metres) Notes and Weather Report and Forecast. 9.5 News gramme. 9.5, Concert Relay and News. 10.30 2.0, Concert by the Station Orchestra. 4.0 to 5.0, News and An- Bulletin supplied by the Polish Telegraph Agency. (approx.), Close Down. Programme of Military Music. 8.15, and Police News. Dance Music nouncements. 8.20, General News Bulletin. 8.30, 920, Sports Notes 9.30, Programme by the Station Orchestra. In the Interval Programme relayed from the "Oars" Restaurant, NAPLES, Call INA (333.8 metres) ; 1.5 kW. -S.30 Warsaw. 10.30 (approx.), Clcse Down. Elementary Instruction in French, by Prof. at 9.30, Sports Not and Results by M. Barrier. a.m., from the Etienne Verdier. 9.0 a.m., Concert of Religious Music. 10.30, Dance Music Programme relayed WARSAW (1,111 metres) ; 10 kW. -9.15 a.m. to 3.45, Children's Corner. 4.0, Variety Concert. 4.30, " Chaumière de Rabat." 11.0 (approx.), Close Down. 10.45 a.m., Church S rvice relayed from a Cathedral. Time Signal. 7.30, News Bulletin. 7.50, Notes by the 10.58 a.m., Time Signal. 11.0 a.m., Relay of Fanfare Harbour Authorities at Naples. 8.0, Time Signal. ROME, Call 1RO (447.8 metres); 3 kW-8.30 a.m., from the Church of Notre Dame, Cracow. U.S a.m., 8.2, Concert of Operatic Music : Duet from A Masked Opening Signal, followed by German Language Report on Aviation Routes and Weather Conditions Ball (Verdi) ; Teco io sto, gran Dio, rendered by E. Lesson. 9.0 a.m., Festival of Sacred Music. Vocal and Forecast. 11.10 a.m., Concert of Symphony Blandi (Soprano) and G. Perrero (Tenor)with Orches- and Instrumental Items. 9.45 a.m. to 120 Noon, Music arranged by the Committee for Education and tral Accompaniment. 9.0, Sports News. 9.50, No Transmission. 12.0 Noon, Opening Signal. 12.5 Culture of the Magistracy of Warsaw. 1.0 to 2.0, Calendar and Review of Forthcoming Programmes. to 1.0, Concert by the Station Trio. 1.0 to 4.0, No Three Agricultural Talks. 2.0, Weather Report and 10.0 (approx.), Close Down. Transmission. 4.0, Opening Signal. 4.5 to 5.30, Forecast. 2.15, Relay of Concert of Symphony Music Variety Concert. 6.50, Press Bulletin and Review. by the Warsaw Philharmonic Society. 4.80, Talk. OSLO (461.5 metres) ; 1.5 kW.- Programme relayed 7.10, Talk for Farmers. 7.15, Sports News and News 4.55, Talk. 5.23 (approx.), Popular Concert. 6.0, by Fredrikastad (434.8 metres), Hamer (555.6 metres), and Announcements. 7.29, Time Signal. 7.31, Miscellaneous Items. 6.23, Talk. 6.45. News Bulletin. Notodden (411 metres), Potagrand (500 metres), Topical Talk. 7.45, " Miss Puck "- Operetta in 6.55, Time Signal. 7.0, Talk by C. Jablonowsk+, en- Risiken 448 metres). -4.50, Carillon. 6.15, Weather Three Acts by Walter Kollo, rendered by the Station titled " Divertissements intellectuels." 7.30, Popular Report and Forecast followed by Press News Bulletin. Orchestra. In the Interval : Reading of a Short Programme by the Polskie Radio Orchestra, conducted 7.0, Time Signal. 7.19, Concert of Orchestral Music. Story. 9.50, Late News and Announcements. 10.0 by J. Oziminski, Mme. M. Zalewska at the piano : 8.30, Weather Report and Forecast and Press News (approx.), Close Down. Waltz from the Opera " Eileen Onegin " (Tchaikovsky). and Announcements. 8.45, Topical Talk. 9.0, 9.0, Aviation News and Weather Report and Forecast. Musical Programme. 9.30, Programme of Dance SEVILLE (Union Radio), Call EA,J5 (375 metres) ; 9.5, News and Information supplied by the Polish Music. 11.80 (approx.), Close Down. 2 kW. -2.0 to 8.0, Concert of Light Music by the Telegraph Agency. 9.20, Police News and Sports Seville Wireless Orchestra, followed by Gramophone Results. 9.80, Dance Music Programme relayed from Close PARIS (Eiffel Tower), Call FL (1,485.15 metres) ; 5 Records. 9.30, Orchestral Selections. 11.0, Flamenco the ' Oaza " Restaurant. 10.30 (approx.), Down. kW.7.55 a.m., Time Signal on 32.5 metres. 9.26 Songs and Dance Music Programme. ,11.30 (approx.), a.m. Time Signal on 1,485.15 metres. 5.0, Relay of Close Down. ZURICH (583 metres) ; I kW. --10.0 a.m., Concert Pasdeloup Concert. 7.10 to 7.20, Weather Report and Programme. 3.0, C mcert relayed front the Carlton Forecast. 7.5 (approx.), " Le Journal Parlé -par STAMBOUL (1,200 metres) ; 5 kW. -3.80, Musical Elite Hotel by the Castellano Orchestra. 6.30, Time T.S.F." with Talles by its Contributors on Health and Selections. 4.30, Stock Market Quotations and Prices Signal. 6.33, Protestant Sermon. 7.30, Evening Medicine, Police Memoirs, Sports News and Racing of Cereals. 515, Programme of Turkish Music. 7.30, Entertainment- Artistes : Mia Martin- Sandrock Results. 7.58, Time Signal on 32.5 metres. 8.0 to Weather Conditions and Forecast and Time Signal. (Viennese Sings). Hernian Ernst (Swiss Songs), and 9.0, Concert of Orchestral Music with Vocal and 7.40, Talk on the History of Music. 8.0, Concert of the Station Orchestra. Otto Strauss at the Pianoforte. Instrumental Solos. 10.28, Time Signal on 1,485.15 Popular Music. 9.0 Late News Bulletin and An- 9.0, Late News Bulletin and Press Report from the metres. 11.15 (approx.), Close Down. nouncements. 9.30 (approx.), Close Down. Neue Züricher Zeitung. 9.30 (approx.), Close Down. A 34

www.americanradiohistory.com JANUARY 91h, 1929. Wfipgs00 41 WUIPliCoa

I It: , 411IlI1, unIrmo ; , lu 1 ;, n' il+ p '1 111111111111111117,r C1.IRRÉNTsoli Tuiuuuivalxmi R,le ilo.l TOPIC.!' Events of the Week in Brief Review.

FREE LICENCES FOR INVALIDS ? pany owning the cable that on each pole NEW STATIC STOPPER. It is understood that a private Bill will bearing the overhead cable was attached The latest inventor of an " atmospheric shortly be introduced in Parliament to a danger warning. eliminator " is a convict in the Nebraska provide free wireless licences for the sick Several members of the jury said that State Prison. Our tame cynic remarks and aged. they thought the cables should be safe- that each of his predecessors ought to bs. 0000 guarded, but the coroner, pointing out 0000 RAILWAY TIME BY WIRELESS. that warnings were displayed, said it was AN INVENTORS' YEAR. foolish to put up wireless pole so close A wireless- controlled clock has been in- a The year 1928 has scored to a live cable. a record in stalled in a New York railway station. the number of patent applications filed, Synchronising sigrtals are received at in- The jury returned a verdict that death was due to electric shock and attached no according to a report issued by Messrs. tervals from the transmitting station at Gee and Co., the patent agents. The Arlington. The clock controls others in blame to anyone. 0000 number filed reached the total of 38,593, different parts of the station. an increase cf 3,214 over the year 1927. 0000 LECTURE ON PICTURE The previous record was made in 1920, NEW TOWER OF BABEL? TRANSMISSION. when 36,672 patent applications were A radio tower, 1,312 feet high, will, it " Picture Transmission " is the title filed. is stated, be erected at Barcelona for the of a lecture and demonstration to be given A large number of inventions during forthcoming radio exhibition in that city. at 7 o'clock this evening (Wednesday) by 1928 related to television, talking films, According to present plans, the tower will Mr. Priechenfried at a meeting of the and gramophone pick -ups. have a circumference of 600 feet and will Institute of Wireless Technology at the 0000 Engineers' Club, Coventry Street, Lon - contain au hotel, a theatre, a museum, WIRELESS TO THE RESCUE. and a library, as well as a broadcasting don, W. 0000 station and commercial transmitter. Broadcast listeners in the Fleetwood A FIVE-DAY WIRELESS COURSE. district will be profoundly thankful when 0000 An amendment to Fleet Orders provides repairs are completed to the Manx sub- SETS FOR BEDRIDDEN POOR. that when any ship carrying an aircraft, marine cable. An interruption to the The provision of wireless receivers for the crew of which does not include a tele- service has led the Post Office to install the invalid poor of Manchester and Sal- graphist air gunner, is about to commis- an obsolete spark transmitter at Hutment ford is the object of a society which has sion, arrangements are to be made for a Barracks, Fleetwood, and this is used to just been formed under the auspices of naval telegraphist' to undergo a five -day preserve communication between Isle of the local branch of Toc H. The society course in aircraft radio telephony at the Man and the mainland. Considerable already has £250 in hand, and is aim- Royal Air Force Base, Gosport. interference is being caused to broadcast ing at a total of £1,000. The hon. treasurer is Mr. D. W. Marsden, Union Bank, St. Mary's Gate, Manchester. Besides monetary donations, the society is glad to receive wireless sets, which should be addressed to the hon. secretary, Toc H, Mark XIV, 1, Eccles Old Road, Pendleton. 0000 AERIALS AND EIEC1RIC CABLES. The second fatality within a fortnight caused by a wireless aerial coming into contact with an overhead electric cable was the subject of an inquest conducted by the Nottingham district coroner on January 1st. While the deceased, Thomas S. B. Martin, of Langwith, was erecting a pole for an aerial on December 29th he took hold of the wire with the intention of fastening it to a stake in the ground. Apparently the wire touched an overhead electric cable carrying 6,000 volts. Martin received a severe shock and burns. He died later in Mansfield Hospital. HOSTILITIES IN AFGHANISTAN. The wireless station at Kabul which, owln to It was stated on behalf of the coni- the severing of cables, is the only link between the Afghan capital and the outside world. A 35

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42 W$P@ho JANUARY 91h, 1929. NOO rl'd

reception in the neighbourhood, and it is progresses from 20 francs for a single - ever, the traffic of that station has been stated that not one of the B.B.C. stations valve set up to 80 francs as maximum for diverted through 2ME, operated from can be received without spark " mush." multi -valve sets. Melbourne by a 500-mile land -line, and Continental listening is badly upset. Objections are raised regarding the uses the latter station is at present too busy The temporary station is, however, to which the money is likely to be put. with commercial messages to handle maintaining an excellent telegram service, It is contended that, after allowing for broadcasting. and wo understand that the normal tele- expenses of collection and the distribu- The fire at Bailan destroyed the roof of graph traffic is being handled. The Post tion of an agreed sum to the smaller the engine room, but was mastered before Office is also employing the wireless regional stations, there will be a surplus any damage was done to the new and station at the Royal Engineers' barracks of 20 million francs. It is feared that costly beam equipment. at Edge Hill, Liverpool. this will be up a 0000 sum employed to build 0000 State -monopolised network of stations on BUS AND COACH." RECEPTION ON THE ISLAND. the B.B.C. pattern. The average French- A sister -journal of The Wireless World Emergency receiving apparatus was sent man seems to resent the notion. makes its debut this month under the to the Isle of Man on December 29th. 0000 title Bus and Coach. The new journal, The equipment, which is of the Territorial A CHRISTMAS "EKCO." which is the first in this country to be portable type, is installed in the Douglas devoted entirely to the growing industry recreation ground and works in conjunc- Over three hundred guests were present at the annual dinner of " EKCO " of passenger vehicle operation on roads, is tion with the temporary transmitter at a monthly publication, excellently "tinted Edgehill. A receiver for the Fleetwood (E. K. Cole, Ltd.), the mains unit manufacturers, held at the Palace Hotel, and illustrated, including among its con- signals is installed at, the Villa Marina, tributors a number of well -known per- Douglas. Southend -on -Sea, on December 22nd. 0000 0000 sonalities in the sphere of travel. In the January number Lieut. -Colonel J. T. C. FRENCH RADIO BILI: RESENTED. FIRE AT AUSTRALIAN Moore- BEAM STATION. Brabazon, M.P., discusses the French broadcast listeners are showing speed limit on roads. hostility to the new radio Bill which, if A fire at the Ballan beam station, 50 it receives the sanction of the Chamber miles from Melbourne, indirectly affected 0000 next month, will introduce taxation on all thousands of broadcast listeners in Britain BOOK RECEIVED. wireless sets. on New Year's Eve. The B.B.C. had " 7'he Ali- Europe ' Three,' " by It is proposed to tax sets according to announced that greetings broadcast by C. M. R. Balbi. -A brochure containing the number of valves. The crystal user 2ME, the Amalgamated Wireless (Austra- intructions and wiring diagram for is not forgotten ; according to the schedule lasia) short -wave station at Pennent Hills, building a simple three valve set. (Lon- he must pay 10 francs (about ls, 8d ) per would be relayed if circumstances per- don : Sir Isaac Pitman and Sons, Ltd. annum. The scale for valve receivers mitted. Owing to the fire at Bailan, how- Pp,' 24. Price 6d.)

The New Year Session. ts: The Lighter Side of Territorial Signals. A reliable indication that the wireless societies Those who have ever thought of joining session the may expect to enjoy a flourishing during NEWS FROM Territorial Army and have not done so, and the remaining winter months is to be found in those who have never thought at all, are prob- the generally attractive tone of their pro- THE CLUBS. ably not aware what a good club a Territorial grammes. It often happens that a club's joy- unit is, especially when as in 47th Divisional ous re -birth In October is followed later in the Signals, there is added to it the great technical session by an insidious form of creeping para- interest of wireless. lysis winch reveals by a gradual diminu- gramme for the coming months comprises de itself by The unit is as much a club as military unit. tion in attendance and a look of distress on the monstrations the leading manufacturers. Full particulars of membership, etc can be ob- There are club rooms, sports and entertainment face of the treasurer. More often than not the committees, rifle shooting, boxing and other malady is almost entirely attributable to a lack tained from the Hon. Secretary, Mr. H. Panter, Holloway School, Hilldrop Road, Camden Road, competitions. of foresight in framing the syllabus, the The headquarters is about to be rebuilt., and plums being N.7. " " placed too early in the pro- by May or June there will be a really first -els gramme. " club house," although one must not call it This year secretaries have wisely reserved so officially. some of the most attractive fixtures to the clos- FORTHCOMING EVENTS. First in the interest of the readers of The ing months of the session, and it may be con- Wireless World will, no WEDNESDAY, JANUARY 9th. doubt, be the wireless fidentially hoped that the interest of members workshop, In which repairs to the unit's own will be sustained at a high pitch. Tottenham Wireless Society - -At 8 p.m. At wireless 0000 10, Bruce Grove. Lecture -Demonstration: stations are carried out and where in- "The Ether Spectrum," by Mr. R. F. G. struction is given in wireless technique, and Stepney Radio Society. Hotness. where experimental work is to be conducted on The Stepney and District Radio Society holds Edinburgh and District Radio Society.-At the lines on which all keen amateurs are work- meetings twice a week -on Mondays from 7.30 to 7 p.m. Visit to the Telegraph Rooni of ing. This coats the amateur a good deal of 9.90 p.m.. and on Wednesdays from 8 to IO p.nt. the Edinburgh O.P.O. stoney when carried out in his own hotue, but The headquarters are at Ocean Street L.C.C. THURSDAY, JANUARY 10th. in the 47th Divisional Signals it would cost hint School. Full particulars can be obtained from Slade Radio (Birmingham).-4t 8.15 p.m. nothing beyond some of his spare time. the Hon. Secretary, Mr. H. Schneider, at the At the Parochial Hall. Broomfield Road. 0000 School. Erdington. Lecture: "Eliminators." by The Social and Sporting Sides. 0000 a representative of Messrs. 11. Clarke and The rooms Co. club will consist of a general room, In Edinburgh. a refreshment room. billiard room, etc. There FRIDAY, JANUARY 11th. This evening (Wednesday), at 7 o'clock, mem- is already a magnificent hall in which fort- South Manchester Radio Society - -At the nightly dances, bers of the Edinburgh and District Radio Co-operative Hall, Wilmslow Road, Dids- boxing competitions, etc., are Society will be conducted over the Telegraph bury. A Debate as to the Best Set far held, in addition to putting It to its legitimate Room of the Edinburgh O.P.O., while on Friday Distance and Purity, with Demonstration. use. If any reader of The 1Vireless World Mr. Youle, of the Marconiphone Company, will Edinburgh and District Radio Society. At would like to attend one of the dances, he has give a lantern lecture before the Society on 8 p.m. At 117, George Street. Lecture: only to apply to the Dance Committee, 47th " Public Speech and Music Amplifiers." Public Speech and Music Amplifiers," Divisional Signals. T.A., Fulham Douse, Fulham Hon. Secretary, Mr. E. I. Robertson, 10, Rich- by Mr. F. route, of The Marconiphone High Street, S.W.O. mond Terrace. Company, Ltd. On the sporting side, there is competition with MONDAY, JANUARY 14th. other units in the Division in cross -country run- 0000 Newcastle- upon -Tyne Radio Society --At ning, boxing and athletic sports. The hall is London, N.W. 7 30 p.m. At 11. Saville Row. Lecture, The Kentish Town and District Radio Society fitted up for boxing, and a short distance away "The History of Radio Batteries," by is the magnificent athletic ground opens a new session on January 18th with a Mr. G. C. Patterson. at the Duke of York's headquarters, which Is designed appeal Radio Society - 7.30 at the unit's programme to to advanced Holloway -At p.m. At when workers as well as beginners. The meetings are the Holloway Evening institute, Hollo- disposal required held every Friday at 8 p.m. at the Carlton Road way School, Hilldrop Road. N -7. Demon- After passing through a course in the riding stration by representative of Messrs. school, those who are keen on organise Schools, under the direction of Mr. A. F. Hem - riding bury (GAY). S. G. Brown, Ltd. Sunday morning rides in Richmond Park. for Hon. Secretary, Mr. A. H. Sartain (2ACN), TUESDAY, JANUARY 15th. which the horses are supplied in the spring and The 40, Harrington Street, Regent's Park, N.W. Bec Radio Society --At 7.30 p.m. At summer. 0000 the Streatham and Tooting Literary If any reader would like to Join such a live Evening Institute. Demonstration by and cheerful " club." lie should call at Fulham Demonstrations by Manufacturers. The London Electric Wire Co., and House (60 yards from Putney Bridge Station on The Holloway Radio Society opened the new Smiths, Ltd. the Underground), and there he will he told session on \Imtday last, January 7th. The pro- all about it. A 36

www.americanradiohistory.com JANUARY 9a, 1929. WRpWiszo 43 `'ulí'Ilcl

USEFUL DATA CHARTS. (Na 1190 STAGE 3o) Diameter of Wire or Strand to give Coil of Minimum H.F. Resistance. AVING obtained P2 from Stages 1 and 2, we now If 27 strand Litz is used in this coil, we find P2=14.7 embark on the last chapter of the search for d, (from Stage 2), and d= o. oo318" (from Stage 3) hence the best gauge of wire or strand for our coil. As we require 27/44 Litz. a ready mentioned, Butterworth has found the curve relating f /P2 to Pd, and this curve forms the basis of The Values of d are Approximate. Stage 3. The high -frequency losses in a coil are partly due to The centre figure shows the skin effect and partly the abac taken to pieces to the magnetic field caused to show the method of by neighbouring turns. In construction. First we the theory it is assumed scale off P2 and f on 1o" that the optimum wire scales, whereupon f / P2 diameter is that which will be given by the makes these two losses middle 5" scale. Then we equal and this assumption, draw the curve connecting while giving correct re- f /P2 and P2d2. Lastly, sults for solid wire coils at 10 5 10' since P2 and P2d2 are on high frequencies, gives a 1o" scales, the middle somewhat too l a r g e line will give d on a 1o" diameter for coils of large scale. inductance working at low Once the constructional frequencies and may be work is finished the scales l ., P2 d2 wrong by a gauge or two of f /P2 and P2d2 can be for stranded wire coils. eliminated and they do not Hence it is desirable' appear on the actual abac. when accurate results are Owing to th ö great range 5 to' required to take the value of P2, it is necessary to of d found from abac 19 split Stage 3 into two as an approximation, and abacs, which are here to calculate the resistance given consecutively. p2 The d for gauges on either side first deals with the range z from the complete for- P2 =0.004 to P2 =4, the mula. second with the range 4 This calculation is te- 4000. dious, and it will be our task in the next abac to Examples 1Ó 10' give a simple graphical For a single -layer solid method for performing it. wire coil, L=200 micro - henrys, l =2", D=4": We Successive processes in the construction of the abac. Comparative Results. have previously found Readers who wish to that P2=0.044.- Find the best value for d when f = ios test the values of d given by the abac will find a wealth cycles /sec. On working through Stage 3 we find that of material in a series of papers' giving the best wire d= o.o34 ", the nearest gauge to which is 20 or 21 gauges for coils of various diameters suitable . for the S.W.G. medium, long and short wave bands. The coil

If, however, we wish to use a 9- strand wire, P2 be- dimensions are given in inches so that no conversion . comes 6.86 from Stage 2, and we find d= o.0059" from the metric system is required. -R. T B. hence we require 9/38 Litz wire. 0000 Again, for a multi -layer solid wire coil with L = An Invitation to Readers. 20, 000 microhenrys, D=/= t =1o" , we find P2= o. o15. Dr. R. T. Beatty, who is contributing this series of Hence at a frequency of 50,000 cycles /sec. the best wire Useful Data Charts, has suggested that some of our diameter is 0.0336" (20 or 21 S.W.G.). Now try a readers may like to propose subjects to be dealt with on short -wave coil. l =12", D=3", N =12. The induct- the same basis as the charts which have already appeared. ance will be 11.4 mics (abac 17), and the coil will be There are probably a number of useful calculations suitable for 6o metres. Assuming solid wire, we find which could conveniently be put into the form of abacs, from Stage 1 that P2= 0.00595 , and since f =5 mega- and any reader who may have suggestions to make is cycles, Stage 3 shows that d= o.o85" (13 or 14 invited to forward them.-ED.

S. W. G.). The Wireless 11 orld, Vol. 22, 1928, pp. 48, 394, 466 A 37

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- 0001 10,000 9.000 8 000 0,115 7.000

-000

0'07 r 0.08 0'003 009 01 0'004

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0 "004 DIAMETER OF WIRE TO GIVE COIL OF MINIMUM H.F RESISTANCE STAGE 3. W.W ABAC P2 0004 -4 DETERMINATION OF DIAMETER OF WIRE OR STRAND N9 19. STAGE 3.

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4,000 0 03 -10.000 - 9.000 - 8D00 3.000 0-04 -7,000 `05 -6,000

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1000 900 800 0.15 -2.000 700

600 02 1500

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www.americanradiohistory.com WITisIl@oo JANUARY 9th, 1929. WopIld

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A Review of Manufacturers' Recent Products. "O.K. SUPREME" TRANSFORMERS. again illustrated on page 618 in our The instrument comes within the cate- These transformers have been put into issue of October 31st last in our review gory of the moving iron type, is dead production recently by F. Toubkin, 33, of the Manchester Show exhibits, but, beat and polarised. The armature is Long Millgate, Manchester, and are made owing to an unfortunate error, it was swung between the poles of a small per- in this case referred to as a two -range manent magnet, and the needle is held in t,iree ratios, 3 : 1, 4 : 1, and 5 : 1. One model only was available for review, this instrument. The meter is provided in the zero position by the effect of the with three scales, one range covering magnetism. Therefore, there are no being the 5 : 1 ratio, and the measured primary inductance was found to be 45.4 0 -30 milliamps., and two voltage scales, springs to go out of adjustment, and as henrys without D.C. flowing. 0 -6 and 0 -150 respectively. the magnet should not deteriorate with We have recently had an opportunity normal handling it is possible that any of testing a sample instrument against slight error each instrument may have laboratory standards. On the milliamp. will remain constant for a long period. scale there was an error of 6 per cent.

at 5 milliamps., - and this decreased pro- gressively over the scale until at 30 milliamps. the error was 1.6 per cent. only. Measurements on the 6 -volt scale showed an error of 15 per cent. at 1 volt, 8 per cent. at 4 volts, and 6 per cent. at 6 volts. At 25 volts the standard laboratory meter read 20 volts, or 20 per cent. lower than the Wates meter, while at 150 volts the error had decreased to 5 per cent. In all cases the model under test showed a tendency to read high. The D.C. resistance on the 150-volt range was found to be 5,000 ohms., and this agrees with the makers' figures, While on the 6 -volt scale our measurements indicated a resistance of 202 ohms. This is within 1 per cent. of "O.K. Supreme" Transformer. the makers' figures. On the 30- milliamp. scale an unusually high resistance of Wales universal test meter. A 3 -range The inductance is high considering the 200 ohms. was indicated ; however, as instrument. step -up ratio, and the transformer would the meter will probably only be used appear to be suitable for use with valves for measuring anode current, a high Now with regard to the function of having an A.C. resistance of between internal resistance can be tolerated. On the various leads : the small stud con- 20,000 and 30,000 ohms. All models are both voltage scales the resistance per volt tact on the lower side of the case is the enclosed in a metal case, and the price is 33.3 ohms., and while this is quite negative contact for both voltage scales. is 12s. 6d. each. satisfactory when accumulators are in use The red flexible lead is the positive con- 0000 we consider that care should be exercised nection for measuring voltages between when measuring the voltages of dry bat- 0 and 150, and the black lead the posi- WATES UNIVERSAL TEST METER. teries, especially the small-capacity type, tive for the 6 -volt range. For measuring No doubt the majority of readers are as the instrument will draw 30 milliamps milliamps, the two small terminals on familiar useful with this instrument, as from the battery It should be used, the side should be employed, the left - we described it on the occasion of our therefore, for checking the voltage only, hand one being the negative, and the review of apparatus exhibited at and not left connected across the cells right -hand the positive. Olympia during September last. It was for an appreciable time. The scales are marked with red and A 40

www.americanradiohistory.com g 121?0 JANUARY 9th, 1929. Wilpshoo Wohild 47 black figures on a silver -faced dial, the ture should be dissolved in each pint of enables the unit to be attached to any red figures being the high- voltage water, but for abnormally high discharge convenient point without first testing for divisions, and the case is finished in crys- currents a saturated solution should be polarity. talline black. The instrument is very used. A thick rubber -covered twin -wire cable compact, being 2in. in diameter and lin. It may be inferred from the discharge terminating in an adaptor connects the in depth. The makers are The Standard curve that 10 or 12 mA. would be an unit to the electric supply, and two Wet Battery Co., 184, 188, Shaftesbury economical current to draw from the Avenue, London, W.C.1, and the price battery. In the actual test the initial is 8s. 6d. current was 15.3 mA., and under this 0000 load the initial terminal voltage low cell RIPAULT WET H.T. BATTERY. was 1.52. After the first rapid drop to The battery under review consists of 14 mA. the current was well maintained 60 cells and has a nominal voltage of for the first 170 hours, after which it 90. It is contained in a black wood fell steadily until- exhausted. The voltage per cell fell to 0.75 at 340 hours. case measuring 194in. x 114ín. x 5in., cam - plete with insulated terminals. The and at this point the addition of more glass containers of the cells measure cells, or the replenishment of the bat- 24in. x1.in. diameter and are enclosed tery, would be necessary to maintain in cardboard cylinders to give a tight good quality of reproduction in the receiver. fit in the case. To prevent creeping of 0000 the electrolyte its top is coated with paraffin wax. The sacs are fitted with OLDHAM H.T. BATTERY CHARGER, Oldham H.T. trickle charger for D.C. TYPE D.C.H T.1. mains. This unit has been designed primarily separate leads, -each fitted with a wander for replenishing high- tension accumulator plug, are provided for the battery. On batteries, and the charging rate is one end of the charger is mounted a small approximately in the order of the drain flash -lamp bulb which glows when cur- imposed on the cells during use. The rent is passing to the battery. As this is model reviewed conforms with the safety a special type which requires only a very recommendations of the I.E.E. in that small current to produce a glow, it also it is housed in a well -ventilated metal acts as a fuse, thereby safeguarding both case provided with a terminal for attach- the unit and the battery from against damage ing an earth lead. When charging should an excessive eurrent pass due to a D.C. supply it is essential that the bat- a short circuit. tery be connected so that like poles from A few measurements were made with mains and battery are joined together, and batteries of different first voltages connected it is generally necessary to ascertain to the unit, the supply being 220 in wall volts the polarity of the sockets the D.C. These are tabulated below. Rlpault wet Leclanché H.T. battery, plug or lamp ho'der. The designers, fore- nominal voltage 90. seeing this difficulty, have fitted a pole terminals to facilitate wiring when re- indicator which enables the user to ascer- Battery Voltage. Charging Current. newing the elements, and the inter -cell tain in a few moments the correct posi- connecting wires are protected by glazed tion for the adaptor. This takes the sleeving. form of a small compass - provided with a 144 volts. 27 milliamps. Full instructions for preparing the card on which is marked a sector in red. 120 35 , is inserted the electrolyte are printed on the inside of If the adaptor correctly, '72 49 Pf the lid, and the solution should consist compass needle moves towards this sector, 48 58 of a mixture of 80 per cent. of No. 1 but away from it if inserted the wrong quality sal ammoniac and 20 per cent. way round. The advantages of this will of zinc chloride free from iron or lead. be obvious, as it obviates the necessity of If the battery is of relatively low For normal use 4oz. of the above mix- marking the lamp holder, and, moreover, voltage, it will be seen that the charging current may be greatly in excess of the drain when operating the receiver ; there- 18 fore the duration of charge should be RIPAULT WET H,T BATTERY - 1'5 arranged just to replenish the cells. Full 14\.- 1 4 instructions regarding the length of time 13 batteries should be charged are given on an instructional leaflet which accompanies 12 1 2 each unit. The price of this useful acces- 1 1 sory is 40s., and the makers are Messrs. < 10 10 w Oldham and Sons, Ltd., Denton, Man- 0.9 O chester. 0000 F- e 08, Z 0.7 ut a- TRADE NOTES. 0 B K 6 F Messrs. J. B. Woodroffe, manufacturers o 0'6 Ó of > the gramophone pick -up of this name, 4 o 4 have moved to new premises at 59, Nor - 0 3 biton Avenue, Kingston -on- Thames. The telephone number is Kingston 4905. 2 02 0000 01 Messrs. Greenhill and Sons, Ltd., 0 0 100 200 300 400 600 Pontifex House, Shoe Lane, London, E.C.4, will in future' be trading as the TIME (WORKING HOURS) Acetate Products Corporation, Ltd., at the same address. The telephone number Discharge curve of the Ripault wet H.T. battery. is unchanged (Central 1306 -1307). A 41 POPERY C; VfL U.S. AiR FORCE www.americanradiohistory.com 48 JANUARY 9th, 1929.

By (Concluded from R. W. W. SANDERSON, page 817 of M.Sc. December igth issue.

Choosing the Correct Capacity for a Receiver.

N the first instalment of this article consideration was than the initial current. An estimate of this average given to the general characteristics of the Leclanché current can only be deduced by someone having expert cell,, it now remains to examine how the greatest knowledge of the characteristics of the set in ques- efficiency can be obtained whèn using this type of bat- tion and the type of battery used. Very approximately tery to supply the H.T. requirements of a receiver. In the average current of any set is between 0.5 and o.6 Fig. 3 the anode currents corresponding to the voltage in of the initial current. - Fig. 2 are shown. It is obviously difficult to estimate the life which Anode Voltage. will be given by a battery which is discharged under 140. 120. 100. such peculiar conditions, that is with a very rapidly Two -valve ...... 10.6 mA. 7.3 mA. 4.4 mA. diminishing load. A discharge on constant resistance is Three -valve, screened grid .. 10.0 7.0 4.4 quite inaccurate, as in case Three- valve, ordinary .. 16.4 9.8 6.3 that a diminution of 20 per Three -valve, two power valves.. 20.0 13.7 8.0 cent, in volts means a 20 per cent. drop in current, Four -valve, screened grid . . 39.0 26.0 16.0 Four -valve, stab lised . . 36.0 22.7 10.0 whereas in this case it means a 5o per cent. drop or Five -valve, portable .. .. 16.4 10.5 more. Six- valve, stabilised .. 56.0 39.0 22.0 The Effect of Falling Anode Voltage. A battery such as B in Fig 1, which falls in voltage in the early part of For purposes of test it has been found that a very its life, may reduce the current so much more rapidly than battery A that fair estimate of life may be based upon the average it may last considerably longer on the set. the distortion and lack of power in the set, starting at an early stage, will easily outweigh this fictitious current throughout life, although this is considerably less advantage. The accompanying table will show the effect of fall- 18 ing voltage on the current 18 taken. In every case the grid bias has been adjusted W 14 for the initial voltage, and W 12 thereafter not changed. a - The receivers concerned J 10 are those made by a well - E known firm e .. and include u all their standard sets. Z 11 W 6 IX CC Safe Discharge Rates. D 4 41SNISh O In order to get satisfac- 2 tory results from a set, with a minimum of trouble, o it is not to 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 380 380 400 advisable overload the battery. A bat- HOURS tery discharge at too high a rate will not give quite as Fig. 3.- Current discharge curve corresponding to the voltage curve of Fig. 2. high a capacity as that dis- A 42

www.americanradiohistory.com JANUARY 9th, 1929. Wilp@heo OIl1 49 Dry Cell H.T. Batteries.- sidered, it would not be wise to use the larger batteries, charged at the proper rate, and although the diminu- as they might conceivably last, say, for a year or more, tion of capacity (on intermittent tests) in the case of during which time the very slow intermittent discharge well -made batteries is not serious, being roughly about may render it impossible to obtain from them their full 20 per cent. for each trebling of the current rate above capacity. Most makers list two sizes of battery only, normal, it is clear that the battery at, for example, three though some have only one, generally the smaller size, times the normal current rate will only last for about a and some as many as four. These are of different quarter of the time. This will mean frequent replace-. shapes, but: they are almost invariably compósed of ments of batteries, involving unnecessary waste of time standard units. If you are in any doubt as to which and more trouble. It is also true that the larger bat- type you have, the following figures should be of ser- teries give rather more ampere hours or watt hours per vice. The ordinary small unit taken by itself is 21in. penny than the smaller ones. It is therefore an economy high, and the diameter is -sin., the larger unit being the in every way to use a suitably large battery. same height, but having a diameter of i /in. In made- Figs. 4 and 5 illustrate this point. They are dis- up units with cardboard, pitch, terminals, etc., the small unit occupies about 0.24 cubic inch per rated volt, 16 the figure for the larger one being 0.46 cubic inch. e", . I The smaller unit should not be discharged at higher -1 / 5 MILLIAMPERES initial currents than io milliamperes, and the larger o ------one (sometimes called " triple capacity ") should be 1.2 employed for initial currents exceeding io and not ex- 20 MILLIAMPERES ~\ \\ ceeding 3o milliamperes. At higher currents than these an uneconomical life will be obtained. 08 10 MILLIAMPERES Parasitic Noises. Where portable sets are considered, the question of 0.4 space and weight will normally forbid the use of the larger type of battery. In these cases, listeners must not be surprised if their batteries want frequent renewals. o The very fact that a portable wireless set has to carry 02 0.4 06 08 10 12 only a small aerial, means that the incoming signals AMPERE HOURS must be amplified to a great degree. Consequently, a powerful set, requiring usually a heavy anode current is required. Fig. 4.- Curves for the small -size cell, showing the influence of the discharge rate on the ampere -hour capacity. Where portability is not really essential, an ordinary set with an ordinary aerial is much more economical. charge curves of the two chief sizes of battery, the From time to time one hears complaints of the standard small one and the " triple capacity," each crackling caused by dry cells, which almost always being discharged intermittently (for four hours per day) suffer for the sins of other components of the set. at the constant currents shown. Crackling caused by batteries can take pla& but it is For simplicity the average voltage of the day's run extremely rare, and will only take place when there has been recorded to avoid serrated curves which would has been a considerable amount of corrosion of the intersect. soldered joints, etc., or where there is a bad connection. Batteries alleged to give rise to crackles have been When to Use Triple- capacity Batteries In order to be able to make comparisons easily, the results have been plotted against the ampere hours given rather than against the time. It is obvious that the -~.I cell discharged at io milliamperes, for instance, will o last rather more than twice as long as the one dis- .i 1.2 charged at 20 milliamperes, and rather more than half MILLIAMP. as long as the 5- milliampere test. It will be noted that 5 there is not a serious difference in capacity upon in- 0'8 \\`15 crease of current rate in either case, but that in the case 20 of the larger cell discharged at 5 milliamperes, the tests upon which extend over a period of nearly six months, 04 there is a tendency for the capacity to diminish as a result of the effect of very slow discharge and standing. It will be seen that with the larger batteries, as would 3 4 be expected, there is a slower rate of fall of voltage for AMPERE HOURS a given current than with the smaller ones. On the other hand, where sets taking very small Fig. 5.- Effect of discharge rate on ampere -hour capacity of anode currents, 5 milliamperes and under, are con - triple- capacity cells. A 43

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50 Wt® hog JANUARY 9th, 1929. WoreIl0 Dry Cell H.T. Batteries. - per kilowatt hour, is not good enough for a circuit tested frequently, but invariably with negative results. where leaking current is paid for at the rate of about Crackles on a set are generally due to a defective trans- 5 per kilowatt hour, which is the price paid even where former or other defective part, or to causes external to a battery with the most satisfactory performance is con- the set. cerned. That crackles are frequently caused outside the set The remedies for this particular trouble are simple, may be recognised from the fact that the intensity varies one being to switch off the H.T. supply from the posi- from time to time, the trouble often disappearing en- tive end, and the other being to feed the loud speaker tirely ; furthermore, sets with eliminators are not immune. through a transformer or choke -capacity circuit so that - Frequently, two sets independently supplied will crackle the loud speaker terminals are practically at earth in unison. (This particular effect has been noticed by potential. In this case, leaks will obviously be the writer.) eliminated. In many houses it is customary for wires to be run into several rooms in each of which a loud speaker may Conclusion. be plugged. This is a fruitful source of trouble where Briefly the rules to be observed in the use of dry high tension supply is concerned. If the loud speaker cell H.T. Batteries are :- is put direct into the H.T. circuit, it follows that if (1) Size of cell. the set is switched off in the usual way by switching Choose a cell as large as possible for reasons of off the filaments of the valves, one or both of the economy (cost per watt hour) and constancy of voltage wires to feed the loud speaker is at a high potential over long periods, the limiting factor being the effects above earth. After a period of years or months, unless of standing upon deterioration. great care is taken both when the installation is made (2) Maintenance. and later, to keep the apparatus in order, leaks will de- There are two alternative methods. velop and act as a steady drain upon the high tension (a) Ideal. Add sections to keep the voltage constant battery during the " off period." Cases of this sort have using high grade voltmeter for check purposes. come under the writer's notice. It must be realised that (b) Compromise. Use large cells and ignore the volt the sort of installation which may be quite good enough drop as it will probably not affect quality very seriously for a lighting circuit where power costs about, say, 6d. until the cut -off point is reached.

LETTERS TO THE EDITOR. The Editor does not hold himself responsible for the opinions of his correspondents. Correspondence should be addressed to the Editor, "The Wireless World," Dorset House, Tudor Street, E.C.4, and must be accompanied by the writer's name and address. CONTROL. MORSE INTERFERENCE. Sir, -Much has been written lately on the subject of trans- Sir, -With reference to Mr. I. Barclay's letter in the issue mission from 5XX being spoilt by the efforts of someone in the of December 12th, may I state my views on the Morse inter- control room at Savoy Hill trying to improve on the music ference question? from the studio. I have been listening to Chelmsford first The shore station at Wick, GKR, appears to be the broadest and then to,5XX since June, 1925. My experience shows that tuned transmitter in the British Isles, and here in Bradford, having an Al set the causes of bad reception are three :- 300 miles south, the supposed 600m. wave can be heard right (1) i.e., Local interference, loud and silent oscillation, etc. down to 460m. when using a single circuit tuner. Port Patrick, (2) Bad land. line. GPK, also using an ancient spark, has another broad wave (3) Over -amplification, resulting in a hiss and distortion, due down to 500m. These two stations and others never reduce to bad control at Savoy Hill. their poyzer because they cannot, as they have only one fixed I : must endeavour remedy yourself. No. You to voltage input. Now the two I.C.W. transmitters at GLV and No. 2 : Is unusual and not the fault of the B.B.C. GKZ cannot be heard outside about 15 miles of 600 metres, and No. 3 : Is the fault of the B.B C., and the remedy is to do hence cause no interference away with the control except to prevent blasting. to broadcasting. However, when a few Continental I.C.W. stations are also working a Recently we had a very good example what there is of fre- jamming on the 600m. wave, and operatore cannot receive their quently takes place. Three songs sung by May Huxley came messages. perfectly me What it will be like when all the British and through and gave very great pleasure; the Continental coast stations are working announcer's voice informing us that the orchestra would now on 600m. with I.C.W. time alone will tell. At present it is possible to read the play a selection, " Cavalleria Rusticana," was so good he might required have been in the room. I settled down to enjoy the selection. 'station through interference when it uses a It started O.K., and then to my disgust the Ham Handed Henry characteristic spark which tunes within 40 metres of 600m., in the control room came to life and thought he could improve on but it will be absolutely impossible when even only three or four it, a hiss started at the back of the music, and this together stations are working I.C.W. with a sharp 600 wave unless the with the music became louder until all was distorted. Tuning receiving station is pretty near to the required transmitter. down does not improve matter's, volume is reduced, but the hiss As an example at present, try to read KAV when PCH is and resultant distortion is still present. It is this hiss, due working. It can't be done at any great distance. to over-amplification, which causes bad reception. I implore Thus while an I.C.W. station is perfect when working by you to continue the campaign to do away with this control. itself, the moment another starts up on the same wave it is no If you consider the addition of one more letter may be a good and repetitions must be demanded. This is where a good help please forward this to the B.B.C. I wrote to them twice spark set has the advantage, and I am in favour of retaining or thrice in 1926 on the same matter, giving concrete cases, and spark transmission for a number of stations where it is going pointing out that over -control was absent from practically all to be essential. outside broadcasts, viz., lunch -time music from restaurants, Finally, don't always blame the operator, it may be the church services, etc., and the total result was better than from ancient " fool -proof " set designed perhaps some ten or twelve the studio. B. H. JONES. years ago. " JIGGER." Folkestone. Bradford. A 44

www.americanradiohistory.com JANUARY 9th, 1929. WimIl@go 32 Worliloll

By Our Special Correspondent. A Control Muddle,Programmes for the Regional Stations. -Wireless Pictures to Stay. - Military Band Problems. -The Ideas Department. -A Difficult Relay.

Music for the " Extraordinary Listener." Anxiety in the Pennines. were to have been opened at the end of " Muddly " would, I think, be a better The B.B.C. mobile transmitter is still December. Now it seems that the B.B.C. word than " medley " (the B.B.C.'s own roaming the Pennines, but no site has yet cannot go into ocbupation until the end choice) to describe the queer assortment been chosen for the Northern Regional. of February. of sounds with which British broadcasting The result is that each of the towns in the The B.B.C. premises occupy the main greeted the New Year. This was the first neighbourhood is being tantalised in turn. part of the building over the Manchester time that the effects department has The sight of the mobile transmitter is not and County Bank. Of the three studios, attempted to mingle music from two dif- one is of the " gallery " type, the first in ferent sources. Side by side with the this country. It is two storeys high, and muffled chimes of St. Michael's we heard FUTURE FEATURES. measures 54ft. by 35ft. Sir Walford Davies' " Solemn Melody," London and Daventry. coon and the result was a racking discord of JANUARY 16TH. -" The Fantastics," a The Programme Problem. play by Rostand. sweet sounds. JANUARY 17TH. Clothes Props," a Pre- Each of the regional centres will have 0 0 0 0 -" posterous Programme. new headquarters before the scheme comes Talk Blending. JANUARY 18TH.- B.B.C. Symphony Con- cert, relayed from the Queen's Hall. into being. To show their consistency of purpose, Daventry Experimental (5GB). I wonder whether the B.B.C. fully the control people might now try the JANUARY 14TH.- Antwerp Concert. realises the magnitude of its task on the equally sensible experiment of blending JANUARY 16TH.-" Memories of Shaftes- programme side when the five regional bury Avenue," a Programme of two talks. If Mr. G. K. Chesterton were Musical Comedy Excerpts. transmitters are in operation? According superimposed upon Mr. Bernard Shaw JANUARY 18TH.-" Bow It Strikes Me," to the plan, at least six exclusive pro- (and vice versa) truth would prevail with by Sir Gerald du Maurier, relayed grammes must be produced daily. from the Private Theatre of the double sway. Royal Academy of Dramatic Art. 0000 0000 JANUARY 19TH. -" Left! Right! Left! " Political Possibilities. a Programme of Marches and March- Exclusive Material. ing Songs. Or a start might be made with the pro- London will produce two programmes, Cardiff. each posed political debate on de-rating. Let JANUARY 15TH.-Welsh Programme. and of the other regional centres all three Parties speak simultaneously Manchester. will be responsible for one. Except in with the boom of Big Ben in the back- JANUARY 13TH. -Light French Music. the case of London, each station will be JANUARY 18TH. -Inter- University Debate. at liberty to take its alternative from the ground. We should then have an im- Glasgow. pressive sound picture, which might well JANUARY 15TH.-Recital of Scottish and transmissions of other stations, but even take the form of a Big Surprise Item. Bebridean Songs. ' on this basis far more original material JANUARY 17TH.-Programme of Music and will be called for than is required to -day. 0000 Verse. 0000 Brookman's Park. Aberdeen. JANUARY 14TH. -" Extra Speshul!I! " a Preventing Work at Brookman's Park has slowed " special " edition of the Radio Re- Clashes up a little in the last week or two. The vue, " Impertinent Waves." It is unlikely that the extra work will difficult task of laying the concrete Belfast. mean additions to the B.B.C. staff. There JANUARY 15TH.-" The Legend of numbers the relay stations foundations has now been completed, but Faustus." are of people at some time must elapse before the concrete JANUARY 16TH. -Bach and Sibelius Pro- and smaller main transmitters who will has sufficiently " set " to carry heavy grammes. lose their present jobs with the introduc JANUARY 19TH. -" Geneviève de Brabant," regional scheme, but they will machinery. an operetta, music by Jacques Offen- tion of the I hear that the official announcement bach. be readily absorbed by the colossal pro- that the station will be working in the gramme department. summer is regarded as highly optimistic Not the least important task will be to by some of the engineers. a welcome one, everyone having decided prevent duplication of items. With the 0000 that distance lends enchantment to the cornucopea pouring out six programmes sound where a twin -wave regional trans- simultaneously, there will be heavy odds The Work Ahead. mitter is concerned. in favour of some awkward clashes. Un- o 00 Not even 5XX, which has quite a large less a special watch is set, there is always machinery hall, entailed anything like the Delay in Manchester. the chance, , however remote, that all amount of work which must be got Meanwhile a delay has occurred in the stations might send out the " William through before the London Regional can opening of the new regional broadcasting Tell " overture at the same moment, with send out a signal. H.Q. at Piccadilly, Manchester, which results too awful to contemplate. A 45

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52 WilpigIl@oo JANUARY 9th, WorIlcl 1929. Wireless Pictures to Stay. tary Band gives 156 performances a year, Willie Rouse. The B.B.C.'s decision to make " Fulto- each containing six or seven selections. The news of the death of Willie Rouse, graph " pictures a permanent feature of This would be a strain on anybody's re- or " Wireless Willie," must have caused their transmissions will supply the neces- pertoire, but it is particularly so with a regret to many listeners. He was one of sary inducement to the general public to military band, as . the number of pieces the pioneers of humorous broadcasting, invest in picture receivers. written specially for this medium does and at one time held a position on not the A contract has just been signed under exceed twenty at the most, including B.B.C. staff as adviser on concert party which the transmission bf pictures begun the latest band compositions of Gustav broadcasts. It was soon decided, how- on October 30th, 1928, will now continue Holst. ever, that his talents were best employed until October 30th next. 0000 in the studio itself. r n O O Friendly Overtures. 0 0 0 0 The Ideas Department. Fultographic Cartoons. However, military bands are wonder- This decision by the B.B.C. has en- fully adaptable to almost all classes of Mr. R. E. Jeffrey, who has relinquished abled Wireless Pictures (1928), Ltd. -the music, from fugues to fantasies on his post of Dramatic Director to found company controlling the ' Fultograph " popular airs, so listeners need not fear a the new " Research Programme " depart- patents -to go ahead with. its plans for ment, tells me that the first fruits of the producing novel picture programmes for new scheme may be expected in about transmission each day. These plans, an two months' time. official PICTURE BROADCASTS BY THE FULTO Ideas, with a capital " I," are the of the company explained to me, GRAPH METHOD. include the transmission daily of cartoons staple food on which the department Daventry- Daily from 2 to 2.30 by famous artists illustrating the events 5XX p.m. except Sunday hopes to thrive. The difficulty is that of the day. Photographs illustrating 1.562.5 metres and Monday. ideas and inspirations are not easily p.m. manufactured. such topical events as occur each day Berlin - Sun. .. 12.45 - 1.30 will also be included in its programme, Königswnsterhausen Mon. .. 12.45 - 1.15 ' Therefore," says Mr. Jeffrey, " we 1,649 metres .. Tues. .. 9.45 - 10.15 together with novel puzzles: Illustrations Wed. .. 12.45- 1.15 invite the aid of listeners. Sometimes a of the people taking part in the daily Thurs. 12.45 - 1.15 man who can boast of no skill in dramatic Fri. .. 9.45 - 10.15 writing is visited by an idea which wireless programme are also to be sent. Sat. .. 12.45 - 1.15 the 00 00 Vienna- Daily, 2.15 to 2.45 B.B.C. staff can turn into a presentable Radio-Wien p.m., and two pic- play." C 518 metres tures after conclusion -000 -c-c- cricket ! of programme. One of the heroes of last week's cricket Inspirations that Pay. match on Broadhalfpenny Down, Ham - It is the fine but fugitive idea for bledon, was Walton O'Donnell, which the con- drought. Last year the Wireless the B.B.C. is willing to pay. I ductor of the Wireless Military Orchestra. Mili- commend this thought tary Orchestra played 160 overtures, not to all who see He tells nie it was a cold job ; if he visions, to all who to mention hundreds of marches, arrange- have grand ideas had said it was a hot one I should have while they shave, to all who see pictures remained polite, but ments of pianoforte works, and selections He was a from opera. in the fire. There are cheques in the air. member of the " Invalids " team, cap- 0000 tained by J. C. Squire, which won O O 0 0 the Return of the Soliloquy. day with 89 runs to the 78 scored by Kilohertz. their opponents, the Hampshire Eskimos. Mr. Jeffrey believes that radio drama I Ever since Captain Eckersley published of the future will contain more psychology believe O'Donnell can claim honours his exposition for being the first member of B.B.C. of the Plan de Bruxelles, than action. He prophesies a return of the no one at Savoy Hill has dared staff to play cricket in England on New to utter the soliloquy, long abandoned by the legi- Year's Day. the word " kilocycles." The more com- timate stage, but still the best vehicle 0 0 0 0 prehensive term " Kilohertz " (kilocycles for enabling the audience to " see " the per second) is on every lip. Fortunately, The mind of the player. The very intimacy Wireless Military Band. the word is always used in the plural; of broadcasting, Reverting in Mr. Jeffrey's opinion, to the more or less serious nobody seems quite certain how to utter it gives it a field of action which side of life, he told me that the Mili- neither in the singular. the stage nor the screen can enter effec- tively. 0000 To- morrow at York Minster. In addition to the fourteen microphones which are to be used at to- morrow's enthronement of the new Archbishop of York, approximately two miles of wire will be in circuit in the cathedral and its precincts. The task of wiring, carried out.by Post Office engineers, proved unusually difficult, as every length of wire had to be concealed. To do this it has been necessary to run the wire up and down pillars and to take it up into the Tower-at a height of 300ft. 0000 Blind Control. To complicate matters during the relay, all the control work will be done out of sight of the ceremony in a small con - trol room. There will be no engineers at the microphone points. The ceremony is to be broadcast from MEASURING SIGNAL STRENGTH. Professor E. V. Appleton is here seen measuring 5XX and the stations of the northern the signal strength of 5GB before a group of students of King's College, London. grouping. A 46

www.americanradiohistory.com JANUARY 91k, 1929. WIp®Il®00 Wad 53

READER QUERIES

"The Wireless World " Supplies a Free Service of Technical Information. The Service is subject to the rules of the Department. which are printed below; these must be strictly enforced, in the interest of readers themselves. A selection of queries of general interest is dealt with below, in some cases at greater length than would be possible in a letter.

The Output Choke. The " Pentode Two." C, and C, replace the reaction condenser. What would be a suitable value for a Please. give me a diagram showing how The first -mentioned may have a maximum choke intended for use in the anode the " Pentode Two" may be modified capacity of from 0.00005 to 0.0001, and circuit of a P.M.256 valve? You in order to use " parellel feed" the second 0.0003 .mfd. will understand that it is to form throttle -controlled reaction-provided 0000 part of a filter output arrangement. this method is suitable. M. N. B. R. G. The circuit you require is given in Electric Supply Regulations. Strictly speaking, the choke should be Fig. 1; in this diagram the reference 1 am thinking of making sip a D.C. chosen in relation to the inductance of eliminator, and, as the negative side the loud speaker winding and not to of my mains is earthed, presume it the valve characteristics. It is assumed will not be necessary to add a con- that its D.C. resistance will not be suffi- denser in the earth lead, as is some- ciently high to cause a serious reduction times recommended. Is this correct? in the actual H.T. voltage applied to R. T. N. the valve. It is sufficient that the choke No, the addition of an extra " earth " inductance should be several times connection to the mains is not per- greater than that of the loud speaker, missible, and you must either insert the and in practice a value of from 20 to 30 usual series condenser or use an aerial - henrys will be satisfactory. grid transformer in which the primary and secondary windings are not in 0000 metallic connection. A Mysterious Fault. 0 O O O Your assistance would be appreciated in tracing a fault which, to me, is quite Where Decoupling Scores. inexplicable, My four -valve set, Is it a fact that the inclusion of decoup after working well for many months, ling resistances and wiring will en- seems to have developed an inter- Fig. 1.-Modified reaction control system able one to reduce the amount of mittent disconnection; after it has for the " Pentode Two." screening in an II.F. amplifier? been in operation for an hour or so D. E. P. a crackling sound lettering corresponds with that in the Up to a point this is correct, but a is produced in the original descriptive article, except loud speaker, and at times signals that sweeping general statement on the sub- die away altogether. Now comes ject would perhaps be misleading. As a rule, however, it will be found the strange part of the affair : if RULES. that an I switch off the electric light in the H.F. amplifier which, with a given (1.) Only one question (which must deal with is room matters seem to be temporarily a single specific point) can be answered. Letters screening system, just on the verge of put right, and signals are again heard must be concisely worded and headed " Infor- self -oscillation will be completely stable at something approaching full mation Department." when modern decoupling devices are (2.) Queries must be written on one side of added. strength. I must add that the mains the paper, and diagrams drawn on a separate 0000 are not connected directly to the sheet. A self- addressed stamped envelope must receiver, although be enclosed for postal reply. I use them for (3.1 Designs or circuit diagrams for complete A D.C. Eliminator. charging my H.T. accumulators. receivers cannot be given ; under present -day Is the Megavox eliminator described in S. T. F. conditions justice cannot done to questions your issue of December 19th suitable Several readers have of this kind in the course of a letter. use means (240 reported a similar (4.) Practical wiring plans cannot be supplied for with D.C. volts), effect, and we have come to the conclu- or considered. provided the rectifier is omitted? sion that the trouble will almost always (5.) Designs for components such as L.F. E. C. be traced chokes, power transformers, etc., cannot be to a defective winding in an supplied. Speaking generally, the smoothing and L.F. transformer or choke, which will (6.) Queries arising from the construction or voltage -reducing arrangements of this be found to have a broken wire with a operation of receivers must be confined to con- eliminator would be suitable for use on microscopic gap structional sets described in " The Wireless between the ends. World " or to standard manufacturers' receivers. D.C. mains, but certain precautions Under certain conditions continuity will Readers desiring information on mailers should be observed, and we would ask be restored by induced surge voltages beyond the scope of the Information Depart- you to wait. for an article on the subject brought about by ment are invited to submit suggestions regarding interrupting the light- subjects to be treated in future articles or which will be published in the near ing circuits. paragraphs. future. A 47 e

www.americanradiohistory.com Vv/te®@ JANUARY 9th, 2-929. WOpIld. Two -volt Valves for the Megavox." Telephone in Series. Pentode - it and Pick -up. is essential to use 4 -volt valves in the I wish to connect five pairs of telephones Will a pentode valve with a pick -up in " Megavox" receiver? If not, will (installed in three different rooms) to its grid circuit give you please sufficient mag- specify suitable types in my receiver, which has a choke filter nification for good loud speaker re- the 2 -volt Mullard range? F. W. S. output. Should these be connected production, or would it be better to Good results can be obtained with 2- in parallel or in series? H. S. L. precede it by another valve? volt valves, and we suggest you should As the total impedance of five pairs of C. H. J. use, in the order given, P. M.12, P. M.2DX, phones in series is likely to be less than This depends a good deal and P.M.22. on one's in- that of your output choke, we recom- terpretation of the expression " good 0000 mend you to connect them in series. loud speaker reproduction." It may be Fading. o 000 stated, however, that the voltage output My 4 receiver is of the ordinary pick-up is not -valve satisfactory enough, H.T. for the Tropics. sufficient except that fading of signal strength I understand fully to "load up " the grid circuit of a that dry batteries are un- pentode, and we recommend is sometimes troublesome. Can you suitable for use in the tropics. you to add suggest a cure? As another L.F. stage, which may be of the A. R. R. I am going to East Africa, taking a If the effect you have noticed is true low- magnification type. fading, short wave receiver with me, will yoit 0000 and is not due to imperfect and suggest a reliable source of H.T. varying connections, we etc., are afraid supply? C. P. B. Loading Coils. that there is no real cure, although the Ordinary dry cells have an extremely In adding a loading coil to an existing use of a receiver with a large " margin of short life in hot countries, and you would receiver, which at present covers safety " in the matter of sensitivity does be well advised to use only the medium wavelengths, should a A.T. accumula- great deal to overcome the trouble. tors, provided that there will be facili- the added inductance be inserted in Obviously, such a set would be normally ties for recharging. If these are lack- the lead joining the present coil to operated in a comparatively insensitive ing, then we suggest " inert " dry cells, the grid, or should it be at the other condition ; during periods of fading, de- or -wet primary batteries, and advise you end of the winding? B. M. S. crease of signal strength would be com- to get in touch with the principal manu- As a general rule you can take it that pensated by use of the volume control facturers, who, in some cases, have de- a loading coil should be inserted at the adjustment. voted attention to the needs of wireless low potential end of the present tuned Devices for automatic regulation of users in the tropics. circuit (the end of which is joined to H.F. input to the detector have been o 000 valve filament). suggested, but we have no information 0000 that they are perfectly satisfactory in Common Batteries. practice. Is there any serious objection to feeding The Choke Filter. 0000 two entirely separate receivers in- I am told that it is an easy matter to stalled in adjoining rooms from one add an output filter circuit by join- A Sensitive "Diode " Receiver. set of batteries? you consider ing an L.F. choke across the existing Will you If suggest a suitable arrangement this plan to be permissible, will you loud speaker terminals of my set, of diode detector and L.F. amplifier describe any special precautions then connecting across it the loud to follow two screened grid H.F. which may be necessary? speaker and a 2 -mfd. condenser, amplifiers? M. D. W. H. L. M. these latter being in series. Is this This subject is rather too involved for Provided the total current taken by simple form of connection as satie- adequate treatment in a letter, but as- the two sets is not beyond the capabili- fa'tory as any other? J. R. suming that your requirements as to ties of the batteries, there is no serious The type of filter you describe really volume are not abnormal, we suggest the objection to your scheme, but it will be serves no other useful purpose than. that arrangement shown in Fig. 2. The range desirable that one, or, better, both, of of keeping D.C. currents out of the loud of the set will be considerably less than the receivers should be fitted with de- speaker windings. We consider it to be that obtainable from the same number of coupling resistances in each anode cir- inferior to the other arrangement in valves with, say, an anode bend detector; cuit. If these precautions are taken, no which the choke is also connected across but, provided the H.F. stages are really difficulty should result from the use of the loud speaker terminals; a lead is good, we do not think you will then taken from the end of the choke have any common batteries, but there may be " real cause for complaint on the score of interaction between the two aerials and which is joined to the anode of the stop- sensitivity. sets of tuned circuits. ping condenser, the other side of which is taken to the negative L.T. terminal through -the loud speaker windings. By o deflecting signal frequency currents from H.T. + the common source of H.T. supply, this 1, -fi--romp-i i- type of filter confers an important 0.001 mfd H.F.D. ad vantage. 0 0 o Power Transformers. aoló .1/y A.C. mains deliver current at a 0 q...- H.T. 0- voltage of 110, which I understand o°I is very much lower b DET. L.F. than the usual i . L.F. figure. I am thinking of making an eliminator, but before starting work c I should like to know if it would be 2nd H.F 141-3E ó necessary for nie to buy an extra ô o transformer to step up this voltage r c to the usual value. M H. H. A large number of commercial trans- G.B - G.B - formers have tapped primary windings in order that they may be suitable for a wide range of input voltages. Accord- ¡.`2 L.T ingly, you should either obtain one of >á these, or else a component specially designed for your supply voltage. There should be no difficulty in this matter, and in any case it is quite unnecessary rig. 2.- Connections of a diode detector and L.F. amplifier following two H.F. stages. to interpose a second transformer. A 48

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AND \ RADIO REVIEW V \V ¡¡ (16 /h Year of Publication) v U

No. g.9o. WEDNESDAY, JANUARY 16TH, 1929. VOL. XXIV. No. 3.

posed mainly of representatives of the wireless industry, Editor: HUGH S. POCOCK. was superseded by a Corporation with a board of Assistant Editor: F. H. HAYNES. governors appointed by the State, we find that one of Editorial Offices: 116 -117, FLEET STREET, LONDON, E.C.4 Telephone: the principal arguments ih favour of that change was that Editorial City 9472 (5 lines). broadcasting Advertising and Publishing Offices: had reached a stage when it was desirable DORSET HOU. E, TUDOR STREET, LONDON, E.C.4. that it should be controlled by an organisation unin- Telephone: City 2847 (x3 lines). Tel(gcanis: "Ethaworld, Fleet, London." fluenced by commercial considerations. COVENTRY : Hertford Street. Telegrams: "Cyclist, Coventry:' Telephone: 6210 Coventry. A Questionable Gain. BIRMINGHAM : Guildhall Buildings, Navigation Street. Telegrams: " Autoprese, Birroingkam. Telephone:. 2970 and 2:,71 Midland. Now to us it seems questionable whether in the trans- MANCHESTER: 260, lleansgate. fer of the responsibility Telegrams: " I1(Ae, Maucheater." Telephone: 8970 City (4 lines). for the broadcasting organisation from GLASGOW : 101, St. Vincent Street, C.2. a group of wireless manufacturers Cl he Broad- Telegrams: "Ili0e, Glasgow." Tekphone: Central 4877, casting Company) to the British Broadcasting Corpora- PUBLISHED WEEKLY. tion we have really attained Subscription Rates: Home, 17s. 4d. ; Canada, 17s. 4d. ; the commendable objective other countries abroad, 19s. 6d. per annum. which we had in view, and removed broadcasting from Entered as Second Class Matter at New York, N.Y. the temptations of commercial interests and entrusted it As many of the tiro its a d apparatus described in these pages are covered by patents, readers are advised, before making u-e of them, to satisfy themselves to a totally disinterested body. that they would not be infringing patents. The wireless Press of this country was allowed the opportunity of giving evidence before the Commission CONTENTS OF THIS ISSUE. appointed to consider the future of broadcasting prior PAGE EDIT )RIAL 55 to the formation of the British Broadcasting Corpora- WATER RIPPLES AND WIRELESS WAVES. BY A. H. DAVIS 56 tion. In their evidence before THE PENTODE AND POWER AMPLIFICATION, BY L. G. A. SIMS 60 that Commission the wire- CURRENT TOPICS ,...... _ 65 less Press asked that a limitation should be set upon PROGRAMMES FROM ABROAD ,. 66 SCREEN GRID VOLTS. BY "RADIOPHARE" 70 the publishing activities of the organisation. This re- BROADCAST BREVITIES .. 72 quest, however, was not NAUEN TO BUENOS AIRES. A NEW TELEPHONY SERVICE 73 acceded to, with the result that VALVES WE HAVE TESTED, ETON " BRITISH VALVES " 75 the Corporation began almost at once to extend their NEW APPARATUS 77 BROADCAST RECEIVERS. THE LOEWE 0.E.333 .. 79 publishing activities, and, particularly, in the case of LETTERS TO THE EDITOR .. .. 81 World Radio permitted REA DBRS' PROBLEMS ...... ,. 83 that publication to compete more directly with the privately owned wireless journals by the inclusion of a similar type of matter in the NOT A PRIVATE QUARREL. editorial pages. THE proposal of the B.B.C. to publish yet another journal under the title of The Listener has A Simple Definition. raised a storm of protest in every section of the We contend that the dispute in regard to The Listener Press, and the question is now being asked whether is not a private quarrel between the Press and the the B.B.C. is not guilty of flagrant abuse of the privi- B.B.C. limited to the question of the publication of yet leges which the monopoly of broadcasting has conferred another journal, but that it is a matter of much wider upon the Corporation. importance and one of principle which deserves the Whilst we are entirely in sympathy with the efforts of fullest consideration ; so that we cannot refrain from the Press to prevent the publication of this new journal hoping that the dispute may lead to a proper definition by the B.B.C., we are surprised to find that this of the scope of the Corporation. instance of rival activity by the Corporation seems to be We have repeatedly stated, as our opinion, that the treated as if it were the first and only instance of en- B.B.C., having been granted the privilege of monopoly croachment by the B.B.C. into the legitimate sphere of in broadcasting should be confined to the microphone as activities of private enterprise. Our readers will re- the only direct means of contact with the public, per- member, no doubt, that we have repeatedly had occa- mitting an exception in respect of the publication of sion to draw attention to the persistence with which this the bare programmes of the British stations. This organisation has sought occasions for entering into corn - simple definition of the legitimate scope of the Corpora- petition with a variety of different industries. tion provides a reply to every criticism, and removes If we investigate the reasons why the old British once and for all any doubt as to what may or may Broadcasting Company, with a board of directors corn- not be a proper activity. A 17

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56 \Mp@IlIWO JANUARY 1929. WoM 16th, ATAR RIPPLES Gy: WIRÉLESS WAVES

An Interesting Analogy Explaining Certain Direction= finding Phenomena. By A. H. DAVIS, D.Sc., Physics Department, The National Phy,ical Labo atory, Teddington, Middlesex. ANY features of wireless waves may be illustrated tion of the carrier wave. On the ripples the distance from by experiments with water waves. Naturally crest to crest of the wave corresponds to the " wave- M there are limitations to any analogy between length " of the sending " station." For instance, taking electric waves, which permeate the whole ether, and the scale of magnitudes to be given by the scale of miles water waves, which are chiefly a surface phenomenon attached, Fig. i corresponds to the carrier wave from confined to the region near a definite plane. Nevertheless, a station with a wavelength of 30o metres. On the same we are usually concerned on land and sea with the mani- scale Fig. 2 is analogous to a station with a wavelength festations of wireless waves which have travelled directly of 500 metres. over the earth's surface, so that the parallel with water waves is not without relevance. Direction Finding. From observation of the ripples at any point, one can Waves from a Point Source. clearly locate the direction of the source. The source is Wireless waves from a vertical antenna spread out over the centre of the outgoing circles, and at any point is in the surface of the earth, a direction perpendicular to being propagated equally in the wave front. Undoubt- all directions. Such propa- edly there are many gation may be represented in methods of locating this per- plan by Fig. 1, which is a pendicular at any point photograph of ripples without knowing the direc- spreading out equally from a tion of the wave -front. For point source. The ripples re- instance, when a small boat present the carrier wave, on a lake or river is subject and an object floated at any to the waves, it rocks least given point on the surface of when the axis of the boat the water would be subject from bow to stern lies per- to vertical oscillations under pendicular to the waves. the action of the waves cor- Even in the dark the direc- responding to the electrical tion of a continuous series oscillations set up in a re- of waves could be located to ceiving aerial. In the wire- some degree of accuracy less case the oscillations are from this fact. Again, with of such high frequency that ripples in a small tank of they cannot be detected by water a floating match will audible means, and the in- o 5 10 sometimes act as a direction

J coming waves are conse- I indicator. If it is pivoted in quently modulated -i.e., in MILES the middle about a vertical the simplest case are divided Fig. 1.- Ripple photo4raph howing uniform prop'gation of axis it will set itself parallel into groups, some of which waves in all , irections tro n ih e s, ,urce. On the scale sho nn the to the waves -i.e., " broad- ripples correspond to wireless waves of 3(10 metres wavelength. are more intense than others. side on " to the direction of In this way the high- frequency waves " carry " a lower propagation and thus show the direction of source. frequency pulsation, which may be detected by suitable Keeping, however, rather closer to the actual analogy means. The propagation of wireless phenomena and with wireless direction finding, we may note that if, at their directional characteristics depend essentially upon any point, we had means of observing the direction of the high- frequency carrier wave, and no attempt has motion of a particle of water as the wave passed over- been made to introduce periodic variations in the ampli- head, we should know the direction of the source, for tude of the ripple source to correspond to any modula- each particle executes a short oval excursion in a vertical A IH

www.americanradiohistory.com JANUARY rbth, 1929. WIp®llitoo . 57 WOg.c1 Water Ripples and Wireless Waves. - the number of special reports relating to the subject plane lying in the direction of propagation of the waves which have been issued by the Radio Research Board at the point. This is illustrated in Fig. 3 (a). of the Department of Scientific and Industrial Research. There is nothing mysterious, therefore, in the fact that It appears that the accuracy of directional receivers under the electrical oscillations set up in a frame aerial should best conditions is of the order of 1 °. Errors may arise, be more vigorous when it is oriented in some directions however, from stray or indirect fields. than in others. Indeed, it is found that the circulation Stray fields may have their origin in electrical currents of electricity in a coil due to a distant aerial is greatest induced by the primary wireless waves in local trees, when the plane of the coil is vertical and lies in the direc- overhead wires, or metal work near the receiving ap- tion of propagation of the waves. Thus at the earth's paratus. Generally speaking, these local errors may be surface the electrical field from an aerial tends to circu- avoided or allowed for. Direction finders on ships are late electricity in a vertical plane through the source, naturally subject to them, owing to the metal employed in the construction of the vessel and in the masts, stays, etc. Local and NIght Effects. A special type of error which occurs chiefly at night is due to indirect waves which have passed upwards into the upper atmosphere and have then been deflected back to earth by, it is supposed, an ionised or semi -conducting layer. In suitable circumstances the boundary of the layer is relatively sharp, and it acts more or less as a reflector. Fig. 4 shows how ripples reaching a partially reflecting surface may be deflected, and illustrates how waves which have proceeded into the upper atmosphere could be returned by a sharply bounded and highly conducting layer. It is not necessary, however, for the change in the properties of the atmosphere to occur suddenly to its full extent at a definite height. If a region of more or less gradual transition is involved, the wireless waves entering the layer may traverse a curved path and emerge again into the lower atmosphere as if reflected from some definite boundary at a rather greater height. Fig. 5 compares the path of reflection at a 0 5 10 sudden discontinuity with such deflection arising from I refraction. To those familiar with the explanation of MILES Fig. 2.- Photograph showing ripple on a scale to correspond with DIRECTION OF WAVE wireless waves of Suu metres wavelength. SOURCE OF just as ripples tend to circulate water. Fig. 3 (b) has RIPPLES WATER WAVE been drawn to bring out the correspondence. WATER SURFACE . (ZERO POTENTIAL) It is upon this property of wireless waves that the radio PATH OF CIRCULATION direction finder is based. It consists fundamentally of OF WATER PARTICLE (a) a plane loop or its equivalent -capable of being rotated about a vertical diameter. The strength of the received signal is greatest when the plane of the loop is parallel to the direction of propagation of the waves, and falls DIRECTION OF WAVE off to a minimum in conformity with a cosine law as the loop is rotated to be parellel to the wave fronts. Since ELECTRIC FIELD TRANSMITTING I / IN WIRELESS WAVE the rate at which signal strength changes during rotation AERIAL I is greatest at the minimum position, this position is used in direction finding. EARTH (ZERO POTENTIAL) ORIENTATION OF CIRCULAR In practice a simple loop or frame aerial is subject to FRAME AERIAL FOR MAXIMUM CURRENT certain disadvantages, particularly when the loop is CIRCULATION (b) small, and more complicated arrangements of crossed coils are, in fact, used. In some the aerial is rotated, Fig. 3.- Diagram comparing water circulation in ripples with but in the Marconi -Bellini -Tosi arrangement a large circulation of current in a frame aerial. (a) Water ripples, (b) fixed system of two frame aerials at right angles is con- wireless waves. nected electrically to two smaller coils, also at right mirage in a desert, Fig. 5 (b) recalls the bending of angles. The two smaller coils thus set up a field corre- rays of light by layers of hot air near the sand. In this sponding to that of the incoming waves, and a small optical case the bending gives rise so strongly to the rotating search coil enables this to be located. appearance of reflection that the illusion of a definite The importance of direction finding is indicated by reflecting surface of still water is created. A f9

www.americanradiohistory.com Sg . WApatoo JANUARY 16th, 1929. Womilcl Water Ripple; and Wireless Waves. - land change their direction slightly so as to appear to In the case of wireless waves, the " Heaviside layer " proceed from a station, say, some 3° to 5° farther to -as it is called after Heaviside, who first suggested its seaward than the actual source. Sometimes even greater existence -is somewhat variable and irregular. In con- errors are experienced. This refraction of waves would sequence, waves reflected from it are changeabl:, they arise if the velocity of wireless waves were .greater over are not necessarily deflected in a perfectly regular sea than over land. Unfortunately, there is some theo- manner, and when they return to the earth's surface retical difficulty here as calculations based upon they are liable to interfere in an uncertain manner with plausible assumptions predict a result in just the the readings of direction finders. opposite direction. Nevertheless, the experimental At night only the upper layers of the atmosphere re- result definitely appears to bt; of the type mentioned. ferred to above are ionised, but The waves appear then to be- during day -time, owing to the have as if they travelled faster action of the sun, the lower atmo- over sea than over land. To illus- sphere also is ionised to some ex- trate this by ripples it is necessary tent. In day-time, therefore, the to provide part of a ripple tank whole atmosphere is more homo- with a false bottom, because geneous, the deflecting boundary ripples in the shallower portion are disappears, and direction finding slower than those over deep water. becomes more reliable. At sunrise Fig. 6 is a ripple photograph ob- and at sunset conditions are in tained in this way. Approxi- turmoil, the boundary is irregular, mately plane waves were gener- and exceptionally large errors in ated in the deep water to repre- direction finding occur, even as sent the analogy of wireless waves great as 90°. Fortunately, night from a ship upon the sea. It is errors being variable, an average seen that, on crossing into the bearing taken over a period of Fig. 4.- Ripple photograph illustrating deflection region of the shallow water repre- some minutes is much more re- of way.s at a partta.ly reflecting boundary. senting land, the wave direction liable than a single observation. was altered, and the wave front We may note that the disturbing influences which observed at O is not at right angles to the true bearing return from upper space are not of sufficient strength of the ship. According to the figure, the apparent bear- compared with the direct waves to affect direction finding lies seawards of the true bearing, and this is actually ing at ranges of less than thirty miles over land from observed to be the case with wireless waves. the sending station. Over sea an even greater range of If, in' view of the theoretical difficulty alluded to, any eighty miles is free from interference, for the primary justification were required for presenting an analogy waves are subject to less attenuation over sea and remain based upon the assumption of greater wave velocity comparatively powerful over a longer range. over sea than over land, it lies in another type of coastal error which the ripples reveal. We have just illustrated Effects. Coastal the error when the waves cross from sea to land. Fig. 7, During the last few years many ships have been fitted however, relates to the case where both the source and with direction finders, so that when fog or other causes the observing station are on land, but near a coastal boundary. The photograph shows that the conditions

observed at O are complicated by the presence of a train . of reflected waves, in addition to the direct wave from /:\ the distant land transmitter. These reflected waves introduce into the direction-finding apparatus at O a component apparently coming from the direction of the sea, and, as a result, lead to an apparent displacement of the source towards the sea. Waves Reflected at the Coast Line. Generally speaking, the intensity of the internally reflected wave increases as the incidence becomes more (a) (b) grazing, and consequently any error in direction finding would depend upon the real bearing of the source, and would be greatest when the true bearing of the trans- Fig. 5.- De4ection of wireless waves by ionised lavers In the mitting station lay more or less parallel with the coast upper atmosphere. (a) Reflection iron horn, geneous layer ; (b) apparent re ection due to refraction in a non -homogeneous layer. line. Error of this type due to coastal reflection is specially interesting in connection with the present article, in render ordinary navigational methods impracticable that its existence was suggested by the writer after ex- they can obtain bearings from wireless stations on land perimenting with ripple analogies to coastal wireless re- and thus fix their positions with some precision. It is ception. The relevant ripple photographs were subse- interesting, therefore, to consider another effect which quently embodied in a letter to " Nature " by Dr. R. L. arises near a coast line. Waves crossing from sea to Smith-Rose, of the National Physical Laboratory, who, A 2t`

www.americanradiohistory.com JANUARY 16th, 1929. WlApe@EO 59 WoTIlc1 Water Ripples and Wireless Waves. - In the work a considerable number of observations were in his extensive records of direction finding by various subjected to analysis_ and compared with accurate maps stations as carried out for the Radio Research Board, of the locality, and, whatever may be the accuracy of had definite evidence of coastal error in waves which the ripple analogy, it is interesting that this later work had travelled entirely over land. It is believed that this confirmed the existence of coastal reflection. was the first occasion on which reflection from a marine boundary had been noticed and made the subject of Directional Transmission. comment. In so far as this article is concerned with illustrations It is additionally interesting that, according to a note of the general directional properties of wireless waves, published this year, Major J. P. G. Worlledge has now it deals with the particular point of view of directional obtained further evidence of reflection of wireless waves at a coast line. During the calibration of a direction - finding station he noted that the bearings of certain transmitting stations using more than one wavelength showed abnormal variations, which were discovered to depend upon the frequency of the waves received. This is what one would expect. For with a given position

COASTAL D.F. STATION

LAND

COAST LINE Fig. 7.- Diagram illustrating how coastal reflection complicates ovèrlani direction -.finding at a coastal station. reception of waves broadcast equally in all directions from the transmitter. It is therefore desirable to mention briefly in conclusion that there is an application of directional wireless which is more or less the inverse of this. In it the transmitter has the frame aerial, and consequently sends out its signals mainly in the direction of the plane of the frame. The aerial is rotated slowly -say, at a rate of once á minute-and in consequence the signal received at any distant receiver varies Fig. A.-Illustration showing how coastal refraction introduces periodically in strength. The transmitter emits a special error in marine direction finding at a coastal land station. signal at the moment it points, say, north, and the direction of the line from the transmitter to any receiving of sending and receiving stations there would be a de- station may be deduced by noticing the time interval finite difference in distance between the paths traversed between N signal and the moment of maximum signal by the direct and . reflected rays. The maximum error strength at the station itself. Indeed, by starting a stop in bearing would be observed when this path difference watch on the North signal and stopping it when signal was an exact number of wavelengths, for then the direct strength is a minimum, the bearing is seen directly upon and reflected waves would arrive in the same phase. the dial. The accuracy of the method is more or less For other wavelengths the two sets of waves would be the same as that in which a directional receiver is em- out of phase, and blurred minima would be observed. ployed, and it is liable to the same sources of error.

The Wireless Picture Receiver. Although drawn correct to scale, it is regretted that an error occurred in one of the dimensions given for the construction of the spindle. This dimension was shown as 7 mm., but is actually 9 mm. (The picture receiver is available for inspection at the Editorial Offices, 116 -117, Fleet Street, London, E.C.4.) Detailed drawing of the Spindle. A 2I

www.americanradiohistory.com Mndcom JANUARY 16th, 1929. WeirIlcd

-- PENTODE

Some Important Con. Precautions Necessary siderations Regarding to Avoid Excessive Peak the Output Circuit. Voltages. By L. G. A. SIMS, M.Sc. r j IHE modern moving -coil loud speaker calls for a battery. Fig. 2 shows such an arrangement, and it will large power output from the last valve of the be clear that the full battery voltage is available at the I receiver, and this has led to the use of valves of valve anode if the resistance of the primary winding of the L.S.5A class, or similar valves with anode voltages the transformer is low, which would usually be the case. of about 35o and correspondingly large values of grid It is, of course, well known that the static curves of the bias. This tendency has meant that the receiver has had valve are not followed when the valve is working, but to become an expensive piece of apparatus for the that another curve, known as the " dynamic curve," amateur to equip and maintain. With the anode voltage comes into operation. The position of the dynamic curve needed it has also had a slight element of personal danger alters for different values of load resistance in the anode associated with it. For these reasons the advent of the circuit and for different methods of feeding the load. pentode valve has been welcomed as the means of feeding moving -coil speakers with considerable power, while 120 using a high- tension battery of only 150 volts. i 1 The general characteristics of this new valve have been , explained by other writers,' but it is felt that there is 110 room for further investigation of the conditions associated with its large power output. It is a device the character - 'V 1 ' 100 istiçs of which differ so materially from those of the well - I . A understood a r triode that it is only to be expected that there may be radical differences in performance between them. 90 Thus it is believed that the following notes will show that, though the pentode may develop considerable GRID SWING 141 V. , A IG BO á power, it does so under special conditions which call for care in its use. E ,o á I î ,V i Dynamic Curves. Ni --.A11 po¡ EWA A I Z Dealing first with a triode of the class usually em- I/ I -." 60 ployed by amateurs for large power outputs, we will I- assume an anode voltage of 35o. This is 5o volts lower 1'1- Amer rlir 4/ IA 50 ¢ than the makers' rated value, but it is the sort of value , 3 which the amateur would be likely to have available if /eI I 110411111/11N1 using his mains voltage in series with an ordinary H.T. II 40 battery of accumulator cells giving about 130 volts. We can, thus, hardly be accused of giving the triode an unfair yI/ I < -ieIII.E111"/ 30 start ! Fig. i shows the makers' curves for this valve. 1i//,5/I /dV/ I/ I In order to work this valve " all out " we may assume AI 20 a voltage swing of about i4o on the grid, fixing our grid Cf 1i/..WilAln MEl bias at - 90 volts in order not to overheat the anode I A unduly (some overheating is often, in practice, almost Ri-1112 til VA IA 41 10 inevitable). At the same time our grid swing of 140 /!Ì41I111I/11/ All volts will not take us too far on to the curved lower NI//EN G'ÍIIP21/1111 o portions of the characteristics. We will consider the usual case of a load fed through ¡GRID BIAS -90 an output transformer or choke condenser unit rather GRID VOLTS than that of a load directly in series with the anode ' The Wirelese World, July 11th, July 18th, and 25th, Fig. 1. -Grid vo'ts -anode current curves for a super -power valve. July For a grid swing cm 141 volts a bias or 90 volts and an anode 1928. voltage of 350 is suggested. A 22

www.americanradiohistory.com JANUARY 16th, 1929. WIp®Il@go 'Until 61 The Pentode and Power Amplification. - 3,40o ohms the anode voltage reached 421, although the Thus the use of a choke -condenser unit or output trans- battery voltage was steady at 35o. The dynamic curve former materially affects the position of the dynamic for this resistance is the line AB in Fig. 1. The line CD curves (and the power output of the valve), as we have, is for 2,35o ohms, and it can be seen that its lower end for instance, the condition that our i : i ratio transformer is also in the region of 40o volts. The actual value 4e virtually inserts the resistance R in the anode circuit for reached was 405 volts. alternating currents only, whereas the insertion of R It can be seen that these dynamic curves are nearly directly in series with the battery would lead to a steady straight, and thus that the anode current and the power loss of battery voltage. We output will both be very pure sine -wave quantities for represent our loud speaker for the present purpose as a 14 resistance, though in practice it has also inductance. The dynamic curves should 12 all pass through the point marked O in Fig. 1, but a 10 they actually fall a little I- aI- below it, as the transformer 3 08 primary has a little resist- Z ance. Fig. 2. -A power valve Now it can be seen that, oI-06 arranged to feed a . loud a speaker through an output if the curves turn about a I- transformer. n point such as O, then their O 04 lower ends must lie in a region of anode voltage higher than that of the high- tension battery. This is fulfilled in 02 practice, the anode voltage rising above and falling below the value 35o, so that the average value is 35o. 0 Measuring Peak Volts. 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8.000 EXTERNAL RESISTANCE R IN OHMS In order to verify this, a circuit was wired up as shown in Fig. 3, using a rectifying valve in conjunction with an Fig. 4. -A power output curve for a super -power triode for various electrostatic voltmeter to form a peak voltmeter in order external resistances. to measure the maximum voltages reached on the a sinusoidal voltage on the grid. The power output is anode.2 The grid was fed from a source of sine -wave shown in Fig. 4 on the assumption that the transformer volte, this being adjusted to give a total swing of about has negligible resistance. This reaches a maximum 140 volts so as to load the triode fully without causing value of about 1.3 watts. There is a wide range of distortion. In measurements which the writer made it resistance variation, about 4 to 1, over which 85 per cent. was found that with an effective resistance 3 R of about of the maximum power will be developed, and we can see that even if, over the range of musical frequencies, the 2 See Journal Scientific Instruments, Vol. I, No. 9, June, 1924, " A Small Peak Voltmeter and an Application," by A. C. loud speaker acts as a varying load, a large proportion Bartlett. of the maximum power will always be developed if the The transformer primary, or a choke, are not of infinite speaker impedance has been chosen correctly at a given inductance, and there is a shunting action, reducing the value frequency. of R. The Case of the Pentode. It is very important, in order to follow the action of the pentode with transformer-coupled load, to note that these results can also be obtained from curves of anode voltage against anode current. Thus in Fig. 5 are plotted several of these curves for the same triode, each separate curve corresponding to a definite grid voltage. It will be clear that the operating point of our triode, whose bias was - 90 volts, will be on the Ea - 90 curve, at the point corresponding to an anode voltage of 35o. This -s0V. point is marked O. We may now draw straight lines at f --- various slopes through this point O to represent the L J various values of the load resistance R. Thus, taking PEAK VOLTMETER the 6,000 -ohm line we see that everywhere along its SINE WAVE OSCILLATOR length a change of current (vertical height) of io amps. corresponds to a change of voltage (horizontal length) of 6o volts. The slope of the line is therefore 6o volts Fig. 3.-The circuit arrangement used to obtain a peak voltage measurement using an electrostatic voltmeter. I0/ 1,000 amps, A 23

www.americanradiohistory.com Wfinhog IANUARY 16th, 1929. 62 Wald The Pentode and Power Amplification.- or 6,000 ohms. That is, the line represents 6,000 ohms. In the same way the second line represents 3,40o ANODE BATTERY ohms. Now with a steady grid bias of VOLTAGE - go, our applied signal of 140 carries e,? iiil// s down to E,= - ióo and up to IA/li Ep= - 20. The .3,40o line cuts the 0 curves for these values of Ea at points i ,o /..;i corresponding to anode voltages of 405 60 i_ i'u`ii ' and 235, and these values of voltage i,.'liiiii will occur at the anode. Thus, by 40 o Ì//i J drawing lines to represent load resist- ao ances across the anode voltage -anode N' I i9 current curves we can predict the peak 20 I 1 4 ,ÌNei voltages which will be reached on the o Sti 'a i anode in practice. ma 50 100 150 200 250 300 350 400 450 5 00 Using the peak voltmeter a series of ¡ANODE VOLTAGEi measurements SWING (R =3,40001 was made with different ANODE VOLTAGE load resistances fed through a z : z ratio output transformer, the grid volt- Fig. 5. -Anode voltage -anooe current curves for the same triode age swing and grid bias being exactly as used through- as used in rig. 4. out this article. After making a small allowance for the resistance and induct- of voltage in the resistance. Taking as our operating con- ance of the transformer, the ditions a battery and screen voltage of 150, a grid bias of :1 RATIO OUTPUT TRANSFORMER results were always in ex- - II, and a grid swing of 22 volts (which we can see 1 tremely close agreement from. Fig. g will be reasonable values), we have that the with those predicted by this operating point is O on the anode voltage.anode current R graphical method. curves shown in Fig. 7, and that the grid swing of 22 We may now turn to the volts will carry us down to the curve for E5 - 22 and up pentode valve, feeding a re- to Eg = O. We may now draw resistance lines through peak voltages as we did for the T sistance load as shown in O and find the anode !150V. Fig. 6. If we use a i : i triode. i ratio output transformer in this case also (this is equiva- Battery Voltage 150, Anode Peak Voltage 500. lent in its action to a choke - A different state of affairs now exists with the pentode FIR. 6. -A pentode coup.ed condenser arrangement), from that which applied to the triode, due to the shape to a foui speaker by a 1:1 output transformer. there will be no steady loss of the characteristic curves. The fact that these tend to become horizontal means

that . the high resistance lines cannot cut the curves 35 lEg=ó for low grid voltage until ( a region of high anode 30 r, ; m op,. voltage has been reached. : BATTERY VOLTAGE =150 m ,, As the resistance is in- o- W ,E:=-5 2 creased the peak anode 25 J ' p11- ` voltage required to satisfy J the resistance line and the 20 .''R ' 22 -volt grid swing be- ` a3Z IE =-10 ' OPER ATING POINT comes extremely high. I- w 15 For instance, the 30,000 - cc cc ohm line calls for a peak U voltage of more than 500, lo although the battery volt- ó o age is only 150. z ` 5 iilk.I -20 ------The importance of this _ Eg_-221 ._- ---^ ------°-°-----^---- is very great, as serious internal damage to the ! : 40 80 120 180 200 240 280 320 360 400 440 4 0 valve may result if volt- ANODE VOLTAGE ages of this order are produced. In order to test the above theory the rig. 7. -Anode voltage -anode current curves for a typical pentode. Owing to the horizonta nature of these curves a dangerously high anode peak voltage may be developed. writer has carried out A 2A

www.americanradiohistory.com JANUARY 16th, 1929. 'fflpeDen5 63 'T/Atild The Pentode and Power Amplification.- A reduction of grid swing will also materially reduce careful experiments, using the exact conditions assumed the anode peak voltages, as can be seen clearly from in this article, and actually measuring the voltage peaks Fig. 7, but as this is one of the least controllable factors produced on the anode, using the peak voltmeter. The in a receiver, due to such contingencies as atmospherics, circuit used was that of Fig. 3, but with the necessary it cannot alone be relied upon to avoid the danger. changes of anode and grid battery voltages and of grid The best way is to keep the anode impedance (repre- swing, and with 15o volts on the screen. There was complete agreement between the results predicted from Fig. 7 and those actually measured, and anode peak 30 voltages of more than 55o were produced. It is unwise 00 to allow voltages of this order to occur in case the valve /, should break down. There is the danger that large peak ,? `"I %/ voltages may start a gas discharge inside the valve if this /ç. 4/ /Ó 2 5 is at all soft, and this, if once started, would probably /^h mean destruction of the electrode system of the valve. , Furthermore, the electrostatic forces existing between M GRID SWING the valve electrodes become considerable with anode voltages of this order. 20 á Safeguarding the Pentode. Although these dangers exist there is, fortunately, i no + f need to incur them. In Fig. 8 is shown the power out- iirI_ I, put of the pentode calculated on the assumption that the output is sinusoidal. It can be seen that the power ill /Iz is very high for values of resistance cc of the order io,000 cc ohms (compare the power with that obtained from the U triode). Now this value of resistance is not likely to L4diUI rlI O I N be exceeded in practice, as the load, even if of high re- VA , o sistance or inductance, is always shunted by the induct- r : '° ance and capacity of the transformer or choke which %/.//,M.- a feeds it and by its own self-capacity. A satisfactory /M%PN power output, equal to about one -half of the maximum 5 obtainable from the high voltage triode, can therefore be obtained without running the anode peak voltage above // /., 300, for we see from 7 is Fig. that this about the value GRID BIAS obtained for a resistance of 10,000 ohms. This value /.I I I -30 -20 -10 o IO GRID VOLTS

N Q B Fig. 9 -Dynamic curves of the pentode for loads of 7,500 and F 30,000 ohms. An output F transformer was employed. a os sented in our work as a sloping straight line, that is, as Z a resistance) fairly low. 0 n will be clear from this that the loud speaker should a not on any account be disconnected from the pentode I- D while the filament of this is alight, for, should this be O 02 done, the output transformer or choke condenser unit at once assumes a very high inductive value which, in turn,

0 will produce dangerously high anode peak voltages. 5,000 10,000 15,000 20 000 25 000 30 000 35 000 The moral is : " Switch off the pentode before chang- EXTERNAL RESISTANCE R IN OHMS ing the output circuit." No dangerous condition can arise if the load resistance Fig. 8. -Power output curve for the pentode. R is connected directly in series with the anode battery, that is, without choke or transformer, as the anode of anode peak voltage should be safe for a well-made voltage can then never rise above 15o volts. But this valve. Another measure of precaution is to include in method of connection may lead to distortion and the anode and screen circuits anti- coupling resistances. power output is less. These have often been advocated in these pages to mini- In Fig. 9 are shown the dynamic curves of the pen- mise back coupling and consequent distortion, but in the tode for loads of 7,50o ohms and 30,000 ohms fed case of the pentode they would also serve the very use- through a i : i ratio transformer. It is evident from ful purpose of limiting any tendency towards a rush of these that distortion will be appreciable for values of current, in the event of a valve becoming soft. resistance much above 7,50o ohms, as the top ends of 25

www.americanradiohistory.com 64 Wflpsils JANUARY zóth, 1929. Wo7fl1 The Pentode and Power Amplification.- To sum up, our results show that a pentode feeding the curves will begin to droop, thus distorting the out- a load through a transformer or choke and condenser put current waveform. We should also notice that the may yield large power free from appreciable distortion .triode dynamic curves are rather superior in every case if the load impedance is carefully chosen, but that a to those of the pentode, though the difference may be dangerous condition may arise if it is carelessly handled. kept small by limiting the pentode load resistance to a On the other hand, a high voltage triode, though expen- value of 7,000 to io,000 ohms. This, as we saw, is sive to equip and maintain, gives a rather purer output also the condition for maintaining reasonable anode of power, is less prone to distortion, and does not call voltage peaks. for special precautions in its use.

A NEW LOUD SPEAKER. The Use of Glow =discharges to Create Sound =waves from Voltage Changes.

r `1HERE have been known hitherto two funda- Experiments indicate that the grow converts the low -. mentally different types of loud speaker ; the frequency currents from the output transformer into usual form depending on electromagnetic prin- sound energy. ciples for its operations, and the electrostatic type which From the point of view of practical working the shape has so far only found a small number of users, but of the two metal parts of the loud speaker is of con- which may still, in view of recent improvements, play siderable importance. - All sharp edges and points must an important part in the future. It is, however, not be avoided, for they apparently give rise to spluttering without interest that recently still another loud speaker discharges, causing noises which mar reception. The principle, entirely distinct from those mentioned, has construction that has so far proved best consists of proved itself workable. M. Brenzinger and Professor a tube with a thin wire F. Dessauer, of the University at Frankfurt -am -Main, stretched through its axis. have observed that certain discharge phenomena, which The connections are so are well known in vacuum tubes as a glow- discharge, made that the wire is the but which can also be obtained at atmospheric pressure positive electrode and the if sufficiently high voltage is available, give rise to tube the negative. About sound -waves under the influence of voltage changes. 10,000 volts are required for The process of production of sound has thus a certain the steady voltage. KILO VOLTS similarity to Duddell's singing arc, which can also be If the voltage - current used as a loudspeaker, as was shown some twenty years characteristic of a loud F 1 g . 2.- Voltage-current ago at physical demonstrations. speaker of this type is traced characteri, I. of the loud The circuit used by Brenzinger and Dessauer is repro- out, a curve such as that of speaker. duced in Fig. 1. A simple receiver is connected to an Fig. 2 is obtained. This amplifier in the last stage of which is incorporated an shows that the discharge sets in at a certain voltage, as output transformer. The secondary winding of this at the point marked ` z," and that it increases with transformer is connected to one of the electrodes of the increasing vo tage as far as point 3, where the discharge takes the form of sparks. In the middle of the characteristic is the working point 2, which gives the correct working voltage. It is reported that with the arrangements described noises practically vanish, and that good and fairly loud reproduction of speech is attained, the clarity of the consonants and " S "- sounds being particularly marked. Since with this type of loud speaker there are no mechanical parts with their attendant inertia, the good reproduction of the highest notes is easily understandable. A further question is Fig. 1. -The lou I speaker AB is connected between an output tra nsf)rmer In the receiver and a source Ut high voltage D.C. which causes bl ue glow. whether the new principle, which on account of the high voltage and con- special loud speaker AB. This loud speaker consists of siderable amplification required is comparatively expen- two pieces of metal to which is connected a sufficiently sive in use, will find a permanent place in practical use. high D.C. voltage to cause a blue glow to spread over It may, however, prove well worth while to follow up the positive electrode. This voltage is provided by a the line opened by Brenzinger and Dessauer, and we high- volt'ge transformer with rectifier and condenser. may soon see further developments. 26

www.americanradiohistory.com JANUARY 16th, 1929. WIpigioo WcxeIlco1

C Z].RRF,ZNTT TOPICS Events of the Week in Brief Review.

I.E.E. ANNUAL DINNER. SPARK STATION'S FAREWELI:. SHORT WAVES AND THE LEAGUE. The Annual Dinner and Reunion of the Telegraphic communication has now To enable the League of Nations to Institution of Electrical Engineers will been resumed with the Isle of Man and carry out a new series of short -wave tests be held at the Hotel Cecil, Strand, Lon- the Post Office spark wireless gear at in the spring the Netherlands Govern- don, W.C., on Thursday, February 7th Fleetwood has been dismantled, much to ment is again placing the Kootwijk sta- next. 0000 the relief of broadcast listeners in the tion at the disposal of the Secretariat for district. During the dislocation of the one experiment a week. The tests will IN THE WEE SMA' HOURS. telegraph service the temporary wireless be in three series. The first will be an Talks on German trade, broadcast at station dealt with 600 telegrams and endeavour to reach America. Japan will a time " when no other European sender thousands of Press messages. be the goal in the second series and Aus- is in operation," are a feature of the 0000 tralasia in the third. service provided by the Stuttgart station. " ELECTRICAL ENTERTAINMENT" Similar experiments were carried out The talks are given on 397.7 metres, MERGER. with varying success last summer. usually early on mornings, The long-expected gramophone-radio òo00 Saturday and BROADCASTING BY WIRE. are in English and Spanish. merger in the United States has been The new " broadcasting finally approved " campaign of 0000 by the directors of the the Conservative Party is to be opened NEW DUTCH SHORT -WAVE Radio Corporation of America and of the by Mr. Neville Chamberlain CONCERTS. Victor Talking Machine on Friday Company. next, when his speech at Liverpool on The new I30 kW. short -wave trans- rating relief will be relayed by Post mitter at Huizen (Holland) is being for- Office land line to audiences at Birken- mally opened to -day (Wednesday) to THE NEW WAVELENGTHS. head, Southport and Widnes. On the carry out a daily Morse service to the following Thursday the Prime Minister's Dutch East Indies. Apart from tele- speech at Newcastle will our Pages be similarly re- graph transmissions, the station will give IN devoted. to "Pro: layed to another hall in the city, and to a weekly concert on Wednesdays with a grammes from Abroad" the Berwick -on-Tweed, South Shields, Stock- wavelength of 16.88 metres. Huizen's wavelength changes involved in toll, West Hartlepool and Whitley Bay. call sign is PHOH1. the new Plan de Bruxelles are The Conservative Party has arranged o o o 0 further relays for near included according to the future, and it THE GERMAN RELAY SYSTEM. the latest will now be interesting to observe Apart from one or two alternative pro- information received at the moment whether the other parties bring up the grammes weekly, the Zeesen high power of going to press. As a number same kind of artillery. 1,648.3 metres, in conjunction 0 0 0 0 station on of stations have not yet conformed HOME CONSTRUCTORS' PICTURE with Berlin (East), Stettin and Magde- with the new plan, certain modifi: RECEIVER. burg, regularly relays the Voxhaus cations must be expected Since the inclusion of the constructional entertainments. The Hamburg broad- during article describing how to build a picture casts may be picked up through Hanover, the next two or three weeks. receiver in the issue of January 9th, it Kiel, Bremen and Flensburg; Munich re- has been learned that component parts taining its relays Augsburg, Kaisers- are obtainable from several other sources lautern and Nurnberg. As hitherto, the Mr. David Sarnoff, who is executive than those mentioned. The following is Cologne programmes are available vice -president of the Radio Corporation, a list of manufacturers supplying the through Langenberg, Muenster and claims that the agreement will make for components specified :- Aachen. greater service to a" single art -electrical Collisison's Precision Screw Co., Ltd., entertainment," o 0 0 0 0000 Provost. Works, Macdonald Road, DEATH RAY : 1929 London,ondon, E.17. " MODEL. LECTURES ON ALTERNATING Prof. Esau, of Jena, who has already CURRENTS. A. Baker, 89, Selhurst Road, South Nor- wood, London, S.E.25., secured publicity by virtue of various A course of ten lectures, with demon- wireless inventions, has New Goodmans, 27, Farringdon Street, Lon. started the strations, on " Alternating Currents and don, E.C. Year with the discovery of a " death Electrical Oscillations," is being given at C. B. Melhuish, 8, Gt. Sutton Street, ray." According to his claim, the Pro- the Sir John Cass Technical Institute, London, E.C.I. fessor can radiate ultra -short waves Jewry Street, Aldgate, London, E.C.3, which Star Engineering Company, Albert Street, will kill small animals instantly by Prof. D. Owen, B.A., D.Sc., Didsbury, Manchester. and exterminate bacillus cultures. Al- F.Inst.P., on Tuesday evenings, from 7- Wilkins & Wright, Ltd., Utility Works, though no aerial is used, transmission is 8.30. The first lecture was given on Holyhead Road, Birmingham. possible up to 250 miles with ordinary January 15th and the remainder follow Williams & Moffat, Ltd., Ladypool Road, wireless valves. A romantic touch is at weekly intervals. Full particulars of Sparkbrook, Birmingham. added by the information that the set is the course, the fee for which is 12s. 6d., Wireless Pictures (1928), Ltd., 14 -16, contained in a cigar box. can be obtained on application. Regent Street, London, S.W.1. A 29

www.americanradiohistory.com 66 WfipdG00 JANUARY 16th, 1929 WopIlcl I RA , i) ® ArM A_BRO DRO / ,

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BARCELONA (Radio Barcelona), Call EAJ1 (350 Barspieler (Monaco) ; Boston, Was weisst den n du metres) ; 1,5 kW. -0.0, Market Prices and Exchange _ wie ich verliebt bin (Jurmann) ; Fox -Trot, Ein Quotations. 0.10, Sextet Selections : Black- bottom, bi -sehen Liebe (Epen) ; Fox -Trot, Ausgerechnet This is my Dance (Dotras Fors) ; Selection from El Dinnerstag (Jurmann) ; Tangs, Schöne Frau, kannst trust de los tenorios (Serrano) ; Andante cantabile du mir treu sein (Geiger) ; March, Das war in Bonn am (Raurich) Waltz, Joli printemps (J. Strauss) ; Rhein (Stipschite) ; Boston, Friihling ist es wieder Selection from The Prophet (Meyerbeer). 8.80, Ele- (Engel-Berger) ; Fox -Trot, Schön ist der Mai in mentary French Lesson by Prof. Martin. 9.0, Chimes Vorderindien (Fall) ; Slew Fox-Trot, Ein Lied aus from the Cathedral, and Weather Report. 9.5 Excha ge Hawaf (Bakloni) Potpourri, Was Euch gefällt Quotations and News. 9.10, Orchestral Music: A22., (Borchert). In the Interval -News and Annoúnce- Fox -Trot, I'd never worry (Swit) ; Habanera, la meats. 5.10, Reading from the 1Vorks of jean Paul, ultima lágrima (Coto) ; One -Step (Debroy- Somers) ; by O. W. Studtmann. 5.45, Esperanto Lesson by W. Sardana, L'aplec de Sant Farriol (Carbonell) ; Selec- SATURDAY, JANUARY 19th. Wischhoff. 6.15, Herr Reign(, Talk : Free Thought. tion from Pan y toros (Barbieri) ; Fox -Trot, How 6.45, Karl Otto Windecker, Talk : The Bourneville long has this been going on (Davis and Wendling- "Garden Factory in England. 7.15, Variety Pro- Skinner). 10.0, Programme relayed from Madrid, All Times are reduced to Greenwich gramme, followed by Dance Music fron, Verbaue. EAJ7. 11.90 ( approx.), Close Down. Mean Time and are p.m. except BERGEN (388 metres) ; 1.5 kW. -5.80, Programme HAMBVR.G, Call HA (in Morse) (392 metres) ; 4 for Children. 7.0, Orchestral Concert, 7.80, Selec- where otherwise stated. kW. -9.15 a.m., News. 10.0 a.m., Programme of tions by the W ener Schra niel Quartet. 7.50, Topical Gramophone Records. 1Lá0 a.m., Weather Report. Talk. 8.0, Orchestral Concert. 8.30, Talk by Victor 11.15 a.m., Exchange Quotations. 11.80 a.m., Ivarson. 9.0, Weather Report, News and Time Signal. Concert relayed from Hanover (298 metres) in the 9.15, Dance Music. 11.0 (approx.), Close Down. Weather Report. 6.27, Topical Talk. 6.50, Talk on Interval at 11.55 a.m., Time Signal. 12.10, News. the following Transmission. 7.0, " The Merry Wives 140, Exchange Quotations. 2.80, Review of Books. BERLIN (Königswusterhausen) (1,649 metres) ; 40 of Windsor" : Opera (Nicolai), relayed from the 8.0, Illustrated Music Talk by Dr. Willi. Heinitz. kW.- 12.45. Phototelegraphy Transmission. 1.80, Stadtheater, Be th n, followed by News and Dance 8.30, Programme of Italian Songs. 4,80, Orchestral Programme for Children. B. K. Graef, Music 2.0, Herr from Voxbaus. 1L0 (approx.), Close Down. Concert. 5.80, Alfred Diller, Talk : The Branches of Talk : Elocution. 2.80, Weather Report and Ex- Social Insurance. 6.0, Talk : In the Footsteps of change Quotations. 2.40. Talk for Women by Helene BRttNN (432 metres) ; 2.5 kW.--8.30, Programme for Goethe, relayed from Hanover. 7.25, Weather Braun. 8.0, Educational Talk by Prof. F. Lampe. Children. 3,45, Talk on the Origin and Evolution of Report. 7.80, " Die Rabensteinerin " -Play in Four 3.30, Programme relayed from Hamburg. 4.30, the Polka. 4.15, Talk : Life on an Ocean Liner. Acts (Ernst von Wildenbruch). 9.45, Weather Report, Prof. Talk : The English Official. Felix lassar, 5.0, 4.30, Talk on Musfr. 4.45, Programme in German : News, Sports Not. Snow Report and Programme Wisniewski, Talk : The Theory of Arbitration in News and Announcements, followed by Songs. 5.15, Announcements. 10., 5, Johann Strauss Concert Social Law -making. 5.80, Elementary Spanish Weekly Repart, full"wed by Concert of Popular relayed from the Ostermann Restaurant. 10.50, Lesson. Prof. Minde- Pouet, Talk : The Lessing 5.55, !slink : Overture to Indra (Flotow) ; Popular Songs ; North Sea and Baltic Weather and Ice Report. in the National. Library. 6,20, Exhibition Herr Fantasia on The Lark Lehár) ; Songs ; Ballet from Mendrzyk, Talk : The Forgotten Hinterland of Lalami (Delibes). 64 , Talk: Czech Literature. Pomerania. 7.0, " Agricultural " Concert. 8.0, HILVERS JM (1,071 metres) ; 5 kW.-9.40 a.m., 7.0, Programme from Prague. 8.15, Programme of Time Signal and Daily Service. 11.40 Police Orchestral Concert : Overture to The Marriage of a.m., Scandinavian Music : Symphonic Poem, Kornholm Announcements. Concert of Trio Music. Figaro (Mozart) ; Nocturne (Mozart) ; March in C 11.55 a.m., (Järr:efeldt) ; Selection (Grieg). 9.0, Programme 1.40, Concert relayed from the Tuschinski Theatre, Major (Mozart) ; Symphonic Poem, Die Moldau from Prague. 9.15, Programme from Prague. Amsterdam. Italian Lesson by Mr. Giovanni (Smetana) ; Overture to Tannhäuser (Wagner), 3.40, followed by Weather Report. News, Time Signal, Rizzini. 4.40, French Lesson by Mr. R. Lafont. BRUSSELS (512 metres) : 1.5 kW.-5.0, Dance Music 5.40, Time Signal. 5.42, Trio Concert. 6.55, German Sports Notes and Dance Music from VGx,ta..s. 11.80 from th.: St. Sauveur Palais de Danse. 6.0, Elementary approx.), Close Down. Lesson by Mr. Edgar Grün. 7.25, Police Announce- English Lesson. 6.25, Intermediate English Lesson. ments. 7.40, Programme organised by the Workers' 6.45, Pianoforte Recital. 7.0, Programme of Gramo- Radio BERLIN (Voxhaus) (475 metres) ; 4 kW. -9.10 Society- Concert and Talk. 11.10 (approx.), a.m., phone Records. 7.30, " Radio -Chronique." 8.15, Close Down. Market Prices. 9.15 a.m., Weather Report, News and Concert arranged by " La Meuse," " L'Antenne " and Time Signal. 10.0 a.m., Programme of Gramophone L'Hebdo T.S.F." 9.0, Topical Talk. 9.10, Concert Records. 10.80 a.m., Exchange Quotations. 11.55 (continued). 10.10, News and Esperanto Notes. HUIZEN (300 metres) ; 4 kW.-Transmits on 1,852 a.m.. Time Signal. 12.30, Weather Report and News. 1.0.15, Orchestral Concert from the Palace Hotel metres from 6.40 p.m. 12,10, Concert of Trio Music. 1.0, Programme of Gramophone Records. 2.0, Ex- Restaurant. 11.0 (approx.), Close Down. 2.40, Programme for Children. 5.10, Gramophone change Quotations, Agricultural Report and Time Selections. 6.10, Talk by M. K. W Gerisch. 6.20, Signal. Dr. Ado Baessler, Talk : North American Gramophone Selections. 6.80, Catholic Bulletin. 2.80, BUDAPEST (554 metres) ; 20 kW.-4.10, Reading. Settlements. 8.0, Mr. P. V. Metzelthin, Talk : The 4.40, Gramophone Selections. 8.0, Lesson in Short- 6.40, English Lesson. 7.10, Lesson in Dress- making. Business Wonsan in America. 3.80, Franz Hessel hand. 6.30, Recital by Aranka Stransky. 7.0, 7.40, Talk by M. L. J. M. Feber. 8.0, Vocal and reads trom his own Works. 4.0, Tea Concert from Concert of Light Music. 8.30, Humorous Musical Instrumental Concert. Hotel followed by Programme An- the Esplanade, Entertainment. 9.30, Time Signal and VI esther nouncements. 5.30, Talk on Medical Hygiene by Report, followed by Selections by Tzigane Orchestra. KALUNDBORG (1,158 metres) ; 7kW.- Programme Dr. Paul Frank. 6.0 Prof. W. Golther, Talk : G e he's also for Copenhagen (340 metres). -6.30 a.m., Morning Faust in Music. 6.1'5, Dr. Johannes Günther, Talk: Gymnastics. 10.0 a.m., Weather Report. 12,15, CRACOW (314 metres) ; 1.5 kW.-4,25, Mr. Imich, The Attitude nt the Modern Man to Lessing. 7.0. Educational Talk 2,0, Programme for Children by Evening Entertainment by Willi Weiss (Tenor), Talk : The Necessity of analysing Food Products. Programme relayed Mis- Ingvald Lieberkind. 2.30, Concert of Instrumental Linus Wilhelm (Double Bass) and the Berlin Lute 4.55, from Warsaw. 5.50, Selections. In the Interval- Recitations by Per and Mandoline Orchestra. 8.0, Strin (berg Programme cellaneous Items. 6.10; Mr. J. Regula, Talk : Foreign Politics of the Past Week. 6.58, Time Signal from the Knutzen. 5.20, Kommandant Floridon, Talk : The in comme n.,r t on of h ight.,nta B.rthdav followed ny Savannas of Centra Africa. 5.50, Weather Report. News 1 ime, S ores Notes and Dance Music. 11.30 Astronomical Observatory. 7.0, Chimes from the of and News. Programme 6.0, News and Exchange Quotations. 6.15, Time (approx.), (lose Down. Church Notre Dame, 7.80, Munk. Chimes from Warsaw. 9.0, Programme from Warsaw. 9.30, Signal. 6.80, Talk by S. 7.0, from Relay of Concert from a Restaurant. 1130. (approx.), the Town Hall. 7.2, Concert of Modern Operetta BERN (407 metres) ; 1.5 kW.-8.0, Concert by the Close Down. Music : March from Eva (Lehár) Waltz from Madame Kursaal Orchestra. 8.80, Programme for Children. Pompadour (Fall) ; Selection (Kollo) ; Vilja's Air Concert by the Kursaal Orchestra. Time from The Merry Widow (Lehár) ; Waltz from A Waltz 4.0, 8.21, DUBLIN, Call 2RN (411 metres) ; 1.5 kW.-1.30, Signal and Weather Report. 6.30, Talk relayed from Weather Report and Concert of Gramophone Selec- Dream (O. Straus) ; Selection from La Bayadère Basle (1,034 metres). 7.0, Talk on the Dialect of the tions. 7.20, News. 7.30 Entertainment by Val (Kalman) ; Cavalier March and Waltz from Polenblut Lake Biel district, by Herr P. Balmer. 7.30, Songs Vnusden. 7.45, Irish Lesson by Seamus O'Durume. (Nedbal). 8.15, Stig Bredstrup, Talk : Child Pictures and Scenes of the People of Lake Biel. 8.30, Concert from Dickens. 9.0, (approx.), News. 9.15, Concert of 8.0, Concert : Overture by the Augmented Station by the Kursaal News Light Music : Overture to The Postillonot Longjumeau Orchestra. 8.45, and Weather Orchestra ; Soprano Solos by Mme. Hefter an ; Report. Concert. (Adam) ; Gavotte tendre (Ganse) ; Selection from 9.0, Orchestral 9.85, Dance Music. Fantasia by the Station Orchestra ; Pianoforte Solos 11.0 (approx.), Close Down. La Belle Hélène (Offenbach) ; Serenade for Strings by Marguerite King Orchestral Selections, (a) Songs; Selection from Le Mdecln maigre lui (Gounod), (b) (Chaminade) ; Fantasia on Danish Student Galopp, Prestissimo (Waldteufel). 10.0, Dance. Music BRESLAU metres) 4 kW. -2.0, Review of Valse Caprice (Rubinstein) ; Marguerite King (Piano) ; (21 from the Industri Restaurant. 110, Chimes from the Books by Richard Film of Orchestra. Tea Terror ' : Steinnot. 2.50 Review the The Station 9.30, and Close Week by Dr. Heinz Hamburger and Gad M. Lipp- Sketch by K. MacCormack's Company. 10.0, Selec- Town Hall. 11.15 (approx.), Down. mann. 3.30, Orchestral Concert : Overture tc N'ald- tions by the Augmented Station Orchestra. 10.30, meister (Job. Strauss) , Potpourri from The Czardas News, R eather Report and Close Down. KATTOWITZ (416 metres) ; 10 kW. -8.0, Concert Princess (Kálmf n) ; Waltz, N interstürme (Fucik) ; of Gramophone Selections. 4.0, Music Lesson by Potpourri from La Bella Wl.ne (Offenbach) ; Waltz, FRANKFURT (421 metres) : 4 kW.-2.0, Report on Prof. F. Sachse. 4.25, Children's Letter Box. .4.55, Durch diet weiten Felder (Lehár) ; Overture to A Snow Conditions. 2.5, Programme for Children. Programme for Children. 5.50, Announcements. Night in Venice (Fah. Strauss). 5.0, Herr Schulrat 2.55, Hints for the Housewife by Fini Platines. 3.l5, 8.10, Talk by Mr. K. Zienkiewicz. 6.45, News and Hoffmann, Talk The Seenery and History of the Orchestral Concert of New Dance Music.: Fox -Trot, Time Signal. 7.0, Talk by K. Rut owski. 7.80, Central Barschtal. 5.25, Sh, rthand Lesson. 5.55, Ich kann Beim grünes Seidenkle d nicht leiden (Egen) ; Popular Concert. 9.0, Weather Report and News. Programme relayed from Kónigswueterhausen. 6.25 Tango, Leila (Dauber) ; Slow Fox -Trot, Er ist nur en 9.80, Dance Music. A 30

www.americanradiohistory.com JANUARY 26th, 1929. Tig11®00 67 W©Tile Programmes from Abroad. - Lesson. 6.50, Talk, News, Exchange Quotations LAHTI (1,504 metres) ; 35 kW. --4.35, Talk. 5.15, Saturday, January 19th. Sports Notes and 1V_ather Report. 7.29, Time Signa Orchestral Concert : ; and Summer Night (Söderström) Topical Talk. 7.45, Band Concert : Military Elegy (Sohlström) ; Gavotte (Mehul- Burmester); March, La Fedelissima ( Cirenei) ; Suite all 'antics Romance ( (Denza). 5.40, Musical Selections. 8.0, Palombi) ; " Pace in Famiglia "- Sketch in One Talk. 6.20, Orchestral Selections : Songs of Persia All Times are reduced to Act (Courteline) ; Selection from (Kauppi) Greenwich Iris (Mascagni) ; Jubannustulilla (Merikanto- Kauppi). 8.40, Topical Talk . Selections (Cirenei), (a) In riva al Song Selections. 7.0, Dramatic Programme. 7.40, Mean Time and are p.m. except Tescio, (b) Danza ; Overture to Saul (Bazzini). 8.50, Orchestral Selections, Finnish Songs and Dances. Topical Talk, News and Close Down. 7.45, News in Finnish and Swedish and Close Down. where otherwise stated.

SCHENEOTADY, Call . XAF (31.4 metres) ; 30 LANGENEERG (462.2 metres) ; 20 kW.- Programme kW.-11.28, Weather Report. 11.30, White tor House Coffee Programme, from also Aix-la- Chapelle (455.9 metres), Cologne (263.2 NAPLES, Call 1NA (383 metres) ; 1.5 kW.7.30, New York. 12.0 metres), and : (Midnight), Phil Spitalny's Music from New York. Münster (265.5 metres). -12.5, Concert Wireless Talk. . Announcements, 7.40, News and 12.30 a.m. (Sunday), Overture to Le Roi d'Yvetot (Adam) ; Waltz, Lebens- Harbour Notes. 8.0, Time Signal. Instrumental Musical Programme 8.2, from Rochester. 1.30 märchen (Fucik) ; Selection from Hans Meiling Concert : Quintet Op. 16 a.m., Concert from the Studio. (Beethoven) ; Quartet Op. 2.0 Lew White (Marschner) ; Selection from The Betrothed (Ponchi- 79 (Saint- Saëns). Il cane della a.m., Organ Recital from New York. 9.0, " Favola," Comedy 2.30 Programme elli) ; Baritone Solo ; Suite, Aus dem Nordlande in One Act (Saint -Saens), a.m., by Mildred Hunt and the followed by Review of the Marimba Orchestra, (Frederiksen) ; Tango, Lieb' Ohre Treue(Polak); Week. 9.50, News. Calendar from New York. 3.0 a.m., 9.55, and Programme Lueky Strike Programme from Boston, Lune de Miel ( Waldteufel) ; Potpourri, Vom Announcements. 10.0, Close Down. New York 4.0 a.m., Rhein zur Donau (Rhode). 1.30, Household Hints. Dance Music from the Hotel De Witt Clinton, Albany 5.0 2.40, Arthur Wurbs Talk : The Bases of Wireless OSLO (497 metres) ; 1.5 kW-Programme relayed a.m. (approx.), Close Down. Technique. 3.0, 'Talk for Women by Adalberta by Fredriksstad (387 metres), Hamar (554 metres), STAMBOUL (1,200 metres) ; 5 Gerhards. 3.30, Dr. Jost, Talk : The Organisation Notodden (207 metres), Poragrund (456 metres).and kW. -3.30, Concert' Legal 4.30, Exchange Rates and Grain Quotations. and Development of German Broadcasting. Rinken (242 metres). -4.0, Orchestral Concert : 5.15, The Concert of Turkish Music. 3.55, Talk for Young People by Dr. Stählin. 4.20, Black Domino (Auber) ; Wye d'amour (Czibulka) ; 7.30, Weather Report and Time Signal. 7.40, Orchestral Concert : English Lesson by Prof. F. Hase. 4.45, Chamber Nocturne (Ambrosio) ; Humoresque (Pchaikovsky) ; Selection ; from A Life for the Czar (Glinka) ; Selection from La Music The Trout Quintet (Schubert). 5.30, Dr. Dreams of Yesterday (Humphries) ; Hindou Song Juive (Halévy) ; Selections Salmony, Talk : Chinese Plastic Art. 5.50, Economic (Rimsky-Korsakoff) ; Berceuse (Gretchaninoff); from the Ballets (Tchai- kovsky), (a) Sleeping Beauty, (b) Le lac Notes, Weather Report and Sports Notes. 6.15, Talk Mclagnine (Moszkovsky) ; Varlaengsler ; des Cygnes. (Hilmboe) 9.0, News and Close Down. for Workers by Dr. Darius. 6.40, Prof. Hessen, Talk : Mariska (Lehr) Intermezzo, Asta (Leopold). 5.0, What do we know of the Soul ? 7.0, Variety Pro- Programme for Children by M. C. Bodtker. 6.15, gramme. 9.0 (approx.), News, Commercial Announce- Weather Report and News. Prof. STUTTGART (374 metres) ; 4 kW. -2.0, Concert by 6.30, A. Fridrichssen Hermann Achenbach (Baritone) ments, followed by Orchestral Selections and Dance Talk : Caesar and Christ. 7.0, Time Signal. 7.2, and the Station Music. 12.0 Midnight (approx.), Close Down. Revue Orchestra. 3.35, Programme relayed from Frankfurt. relayed from " Le Chat Noir." In the Inter- Time vals- Weather Report, News and Topical Talk. 5.0, Signal and Weather Report 5.15, Dr. Rob. Dance Braun, Talk : Freiherr von Reichenbach, The In- LEIPZIG (382 metres) ; 4 kW.-2.0, Weather 10.0, Music from the Hotel Bristol. 11.0 Report. (approx.), ventor of the Od Doctrine, on the 60th Anniversary 8.30, Orchestral Concert : Overture to Der False Close Down. of his Death. 5.45, Dr. Wolff, Talk : Book -keeping. Stani zlas (Verdi) ; Ballet Suite, Hiawatha (Coleridge - 6.15, Reading from the Works of Jack London, by Taylor) ; Selections PARIS (Eiffel Tower), Call FL (1,488 metres) ; 5 kW. from The Girl of the Golden West -. Alfred Beierle. 7.0, Time Signal and Notes. (Puccini) Two Studies for S.rings (Sinigaglia), 5.0, Pa deloup Concert. 7.10, Weather Report Sports 7.50, Le 7.15, Vocal and Instrumental Concert of Swabian (a) Rain Song, (b) Capriccio, Slavonic ; " Journal Parlé." Dance (Felber) Music : Serenade for String ; Selections from Hocheit Trio (Halm) Recitations,. tanzt Walzer (Ascher). 4.45, (a) Epigrammes (Weckherlin and Haug), (b) Der ka te Wireless News and Talk. 5.20, Weather Report and PARIS (Petit Parisien) (336 metres) ; 0.5 kW.--8.45, Michel Gramophone Selections, (Schubart) Soprano Solo, Ballade (Zumsteeg) ; Time Signal. 5.30, Programme relayed from Königs Talk, and News. 9.0, Recitation, Schulz Concert : Overture to The Nuremberg und Pfarrer (Sebastian Sailer) ; wusterhausen. 8.0, Prof. Georg Witkovsky, Talk ; Doll (Adam) Selection from La Recitation, Aus den Kindheitserinnerungen (Just. Lessing as Art Critic. 6.30, " A Masked Ball " : Opera part du Diable (Auber). 9.25, News Kerner) Pianoforte Solo from The Passion (Her- in Four Acts (Verdi), relayed from the and Announcements. 9.80, Symphony Concert : Opera House, mann Remuer) ; Soprano Solo, Lieder an einen Chemnitz. First Movement of the Fourth Symphony (Glazounoff) ; 9.0 (approx.), Labour Market Report, Freund (Hugo Hermann) ; News, Sunday Villanelle for Horn and Orchestra (Dukas). 10.0, Recitations (Dr. Strauss), Programme Announcements and (a) Ermunterung, (b) Letzter Hauch, (c) Zu Cannstatt Sports Notes. Dance Music News and Concert : Waltz Suite (Brahms) ; Aubade 9.30 relayed from Voxhans. an der Brucken ; Soprano Solos, (a) (Erlanger) ; Norwegian Dance (Grieg). Two Songs (Zoller), (b) Aus den Mörike-Liedern (Hugo Wolf ) ; MADRID Radio), Recitation, Ins (Union Call EAJ7 (435 metres) ; PARIS (Radio -Paris), Call CFR (1,769 metres) Zeichen des Steinbocks (Kurz) ; 3 kW. 115 Soprano ; -7.0, Chimes, Exchange Quotations and Dance kW. -- 12.30, Concert of Columbia Gramophone Solo, Liebesleben (Knayer) Song, Unend- Music. 8.0, Dr. Zito, Talk : Inventors lichkeit (Sculz) Recitations ( Schossen), (a) Das and In- Records : Selections from Petrouchka (Stravinsky), war ventions. 825, Time Signal and News. 10.0, Chimes, by a Symphony Orchestra, mein Gang, (b) Neujahr String Quartet (Bleyle) followed conducted by the Composer ; " by Selection from " Curro Vargas " : Musical Pianoforte Solo, No. Im Schwobaländle inch goat sein " : Humorous (Chap.). Etude 23 (Chopin), by Francs Dialogue by Play In the Interval at 12.0 Midnight Plante Pianoforte Solo, Premiere Ballade (Chopin), Erna Fassbinder, Ernst Stockinger and (approx.), News. 12.30 a.m. (approx.) (Sunday), by Robert Casadesus Folk Song Quartet, followed by Dance Music from the Close Down. Choral and Orchestral Selec- Pavillon Excelsior. tions from Boris Godounoff (Moussorgsky) ; Ready for the River, by the Trix Sisters ; Good Night, by TOULOUSE (Radiophonie du Midi) (383 metres) MILAN, Call 1MI (504 metres) ; 7 kW. Time Ted Lewis and his Band ; Minnetonka, by the Picca- 7.80, 8 kW.-12.45, Concert. 8.0, News and Exchange Signal, Wireless Talk and Announcements. 7.45, E. dilly Players ; Hello, Montreal, by Ted Lewis and Quotations. 8.30, Instrumental Concert : Pianoforte M. Ciampelli, Talk : The History and A sthetics of his Orchestra ; Get out and get under the Moon, by Solos, (a) Malaguena (Lecuona), (b) On Wings of Music. 8.0, Opera Relay from the Scala Theatre. In Paul Whiteman and his Orchestra ; Tango, Retintin Song (Liszt) ; Harp Solos, (a) Sicilian (Respighi), the Intervals, Reading by Angelo Sodini, News and by Tipica Argentina Salvador Pizarro's Orchestra ; Economic Notes. Tango, Desengado, (b) L'Hirondelle (Renié) ; Piccolo Solos, (a) Piccolo by Lucchesi's Orchestra In the Polka (Darnel-0, (b) Interval, News. News, Le Rossignol (Blémant) ; Oboe 2.0, Exchange Quotations Solos, (a) Sous les Sapins (Blémant), and Religious Information. 3.45, Dance Music by (b) Mazurka, Une MOTALA (1,365 metres) ; 40 kW.- Programme also soirée prés ; the Joss Ghislery Symphonians. In the Intervals, du lac (Leroux) Accordion Solos, (a) One - for Stockholm (438 metres), Böden (1,200 metres), step, Une gosse rosse (Tagson), (b) Waltz, Je voudrais Göteborg (346.8 metres), (229 metres), News. 6.30, Agricultural Report. 8.45, Musical Malmö Oster- te fuir (Peyronnin) ; followed by Programme arranged sand (720 metres), Sundsvall (545.5 metres). Selections. 7.30, Pianoforte Lesson by M. Pierre -4.0, Lucas. 8.0, Talk on The Success by La Dépêche. In the Interval : Selections of Concert of Gramophone Selections. 4.80, Programme of the Stamp Anti - Viennese Waltzes from (a) Tuberculosis Campaign, followed by News and Ex- The Count of Luxembourg for Children. 5.0, Programme of Old Dance Music. (Lehár), (b) Die Fledermaus (Strauss), (c) The Merry change Quotations. 8.15, Concert : Songs by 8.0, Selma Lagerlöf Reading, relayed from Karlstad Mme. Widow (Lehár), (d) Bonbon de Vienne (Strauss). Renée Danthesse ; Selections by Mario Cazes ; (219 metres.) 0.45, Talk : Professions and Pro- Dance 11 0, North African News. 11.30 (approx.), Close Down. fessionals. 7.0, Programme relayed from a Theatre. Music by the Joss Ghislery Symphonians. In the 8.0, Topical Talk. 8.15, News and Weather Intervals, News. Report. VIENNA (520 metres) ; 15 kW. -4.45, Chamber Music : 10.0, Dance Music. 11.0 (approx.), Close Down. POSEN Pianoforte Solos, (a) Arabesque (Schumann), (b) (343 metres) ; 1.5 kW. -4.15, Talk on Scouts. Rondo in E Major 4.30, English Lesson by Dr. Arend. 4.55, Programme Flat (Hummel), (e) La fille aux MIINICH 4 cheveux de lin (Debussy) ; 'Cello ( ; (537 metres) ; kW.- Programme relayed relayed from Warsaw. 5.50, Talk. 8.15, Musical Sonata Brüll) by Augsburg (566 metres), Kaiserslautern (273 Interlude. Sonata in C Major for Two Pianos (Bach) ; Sonata in metres), 8.45, Talk for Women by Mme. Swidzinska. D Major for Two and Nuremberg (240 metres). -5.0, Trio Con- 7.0, Miscellaneous Items. 7.30, Programme relayed Pianos (Mozart). 6.0, Siegfried Lcewy, : cert. 5.35, Labour Market Report. 6.0, The Letter from Warsaw. In the Intervals, Theatre and Talk The Centenary of the First Performance Box. 6.80, Reading from Modern Cinema of Faust, January 19th, 1829. Baritone Norwegian Litera- Notes and News. 9.0, Time Signal and News. 9.30, 6.30, Song ture. Recital by Celestino : 7.0, Concert of Light Music : Grillenbanner Cabaret Entertainment. 11.0, Concert arranged by Sarobe Basque Songs (arr. Marsch (Komzak) ; Donosti), (a) Nik Overture to A Night in Venice La Maison Philips. 1.0 a.m. (Sunday), Close Down. baditut, (b) Goiza, (e) Uneak, (d), (Joh. Strauss) ; Waltz, Wenn die Füsschen sich heben Euskal Eria ; Air from The Barber of Seville (Rossini) ; (Gilbert) ; Potpourri, Schlager auf Schlager ( ; Air from A Masked Ball (Verdi) ; Seguidilla murciana Lincke) PRAGUE (343 metres) ; 5 kW.-3.30, Orchestral Entr'acte from La Vie Parisienne (Offenbach) ; Waltz (de Falla) Jota (de Falla) ; Air from The King of Concert : Quartet in D Major, Op. 165 (Schubert) ; from The Count of Luxembourg Lahore (Massenet) ; Air from Hamlet Lehár) Golden Fox- Quartet in D Minor, Op. 34 (Dvorak). 4.30, Talk by (Thomas). trot (Salabert) Potpourri, From Heidelberg to 8.10, Time Signal and Weather Report. 8.15, ," A Dr. Herben. 4.40, Dr. Cipera, Talk for Workers : Barcelona (Borchert) Washerwomen's Ball " : Humorous Selections March Folies Berg res (Lincke) ; How to Economise with Fuel in Industry and at from a 9.20, News. 9.45, Dance Music from the Galerie Home. Popular Old Viennese Carnival Custom (Edmund Arcadia. 4.30, Agricultural Programme. 5.0, German Skurawy), followed by 1.80, Trio Concert : Overture to Poet and Transmission. 8.0, Popular Orchestrai Concert. Phototelegraphy Trans- Peasant (Suppé) ; mission. Selection from Carmen (Bizet) ; 6.45, Scientific Talk by Dr. Sommer -Batak. 7.0, Violin Solo, Berceuse (Daube) ; Selections (Reger), Popular Programme. 8.16, " The Gloves " Bilhauer WARSAW (1,415 metres) ; 10 kW.-5.50, Miscell- (a) Waldeinsamkeit, (b) Mit Rosen bestreut ; Tam- and Hennequiri). 9.0, Time Signal, News and Theatre aneous Items. 8.10, " Radio-Chronique," by Dr. M. bourin chinois for Violin (Kreisler) ; Selections Report. 9.25, Dance Music. Stepowski. 6.35, News. 6.56, Time Signal. 7.30 (Albéniz), (a) Rumores de Caleta, (b) Sevilla ; Noc- turne from A Midsummer Night's Dream (Mendelssohn) Concert of Light Music. In the Interval : Theatre ROME, Call IRO (444 metres) ; 3 kW.-4.30, Concert Notes. 9.0, Weather Report and News. 9.5, Police Waltz from Der Rosenkavalier (R. Strauss) ; Wiegen- of Vocal and Instrumental Music. 5.30 Wireless Announcements and Sports Notes. 9.30, Dance Music lied (Brahms). 12.80 a.m. (Sunday), Close Down. Experiments. 5.40, Morse Wireless and tTechnique from the Oaza Restaurant. 10.30 ( approx.), Close Down. A 31

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08 W©rlal JANUARY 16th, r929. Abroad. Station Trio. 2.10, Concert Programme. 5.30, Programmes from - JANUARY 20th. Relay of Divine Service (on 1,852 metres) and Address ALGIERS, Call PTT (353 metres) ; 1 kW.-12.30, SUNDAY, from an Evangelical Lutheran Church at Amsterdam. Instrumental Concert by the Station Orchestra con- Sermon on the 30th Verse of 3rd Chapter of the Gospel : ducted by C. Cerlini (I lautist). Violin S 1, Sérénade ' according to SL John. Preacher : J. P. v. Heest. a Kubelik (Drdla) rendered by M. A. Gonzales. All Times are reduced to Greenwich 7.10, Talk. 7.40 (approx.), Concert Programme. 10.25, Epilogue by the Choir under the direction of BARCELONA (Radio Barcelona), Call EAU (350 Mean Time and are p.m. except Mr. Jos. H. Pickkers. 10.40 (approx.), Close Down. metres) ; 1.5 kW. -1L0 a.m., Cathedral Chimes and European Weather Relay. 11.5 a.m., Spanish where otherwise stated. RA.LUNDBORG (1.153 metres) ; 7 kW.- Programme Repot and Forecast, followed by. Aviation Notes and also for Copenhagen (340 metres). -9.0 a.m., Relay Route Conditions. L30, Musical Selections by the of Divine Service, with Sermon from a Church in in the intervals. Iberia Trio. Gramophone Records Copenhagen. 10.30 a.m. to 10.40 a.m. (Halnndborg 2.45 to 5.30, No Transmission. 5.30, Opening Signal tion'of M. Ikon Leroy. 0.30, Concert of Chamber only), Weather Report and Forecast from the Copen- followed by Part Relay of an Opera from the Grau Music. 720, Radio -Chronique. 8.0, " Eva " -O 'eretta re.c..yed from the B- rgsres hagen Meteorological Institute. 5.50 (Kalnndborg Teatro del Liceo. Exchange Quotations and Market (L hár) F emi.h Folie- only), Weather Report and Forecast from the Copen- Prices in the interval. 8.0 to 8.20, Bulletin from the Theatre at Prussels, lalowed by Late News and hagen Meteorological Press News and from Evening Press. 1.10 Institute: 80, Catalonian Institute of Agriculture at San Isidro. Announcenents the Announcements. 8.15, Time Signal. 8.30, Talk. 8.20, Concert Prrgramme by the St&ti n Orchestra : (approx.), Close Down. 7.0, Relay of Chimes from Copenhagen Town Hall. Aphredite. Suite (H. Février-Mont n), (a) La Reine 7.5, Concert Programme. 9.0, Orchestral Concert Bérénice, (b) La Kasbah, (c) Dans les jardins de la BUDAPEST (554 metres) 20 kW. -8.0 a.m., General and Hints' for Women. by the Station Orchestra. Fantasia for Oboe and déesse, (d) Danse au clair de lune. 8.40, Sports Notes. News and Announcements Orchestra (Vincent d'Indy) rendered by Henry Munck. 9.0 (approx.), Close Down. ' 9.0 a.m., Relay of Divine Service and Address. 8.15, including Talks 10.0, Dance Music Programme by the Palace Hotel Wireless Educational Programme, Orchestra, conducted by Teddy Petersen. In the BERGEN (388 metres) 1.5 kW. --9.30 a.m., Relay and Musical Recitals. interval at 11.0, Chimes relayed from Copenhagen of Religious Service. 1130 a.m., Weather Conditions Town Hall. 11.30 (approx.), Close Down. and Forecast followed by News Bulletin. 7.0, Orches- COLOGNE (203.2 metres) ; 4 kW.-Programme also tral Selections. 7.50. Talk on a Topical Subject. for Aix -la- Chapelle (455.9 metres), Langenberg (462.2 8.0, Talk by Murtin Birkeland : " Christopher Bruno." metres) and Munster (265.5 metres).- .45 a.m., KATTOWITZ (410 metres) ; 10 kW.-9.15 a.m., 9.0, Weather Conditions and Forecast, Late News and Lesson in Self Defence by Dr. Ludwig Bach. 7.5 Sacred Service Relay. 10.58 a.m., Time Signal. 1L Announcements and Time Signal. 9.15, Dance Music a.m., Shorthand Lesson by Hans Molitor. 7.25 a.m., a.m., Weather Conditions and Forecast. 11.15 a.m., Programme. 31.0 (approx.), Close Down. Survey in Esperanto by Alfred Dormanns of the Concert of Light Music by the Station Quartet. 1.0, Programmes for the Week. 7.30 a.m., Lesson in Talk : "The Silesian Gardener." 120 and 140. BERLIN (Königswusterhausen) (1,849 metres) ; 40 Esperanto by Alfred Dormanns. 8.5 a.m., Festival Two Agricultural Talks. 2.0, Weather Rep rt and kW. -7.55 a.m., Relay of Chimes from the Garrison of Sacred Music with Vocal and Instrumental Items Forecast. 2.15, Concert of-Symphony Music by the Church at Potsdam. 9.0 a.m., Recital of Sacred Music and Address. 12.0 Noon, Concert of Orchestral Music. Warsaw Philharmonic Orchestra, conducted by M. with Sermon relayed from Verbs -.is. f flowed by Berlin 1.30, Talk. 2.15, Talk by Marie -Theres van den Glinsky and Mme. M. Marco (Violinist) Prelude to Cathedral Chimes. 10.30 a.m., Relay of Orchestral Wyenberg on Books and .Periodicals for Women. "Mona Lisa " (L. Rozycki). 8.0, Miscellaneous Concert from Vexhaus. 12.45, Experimental Trans - 5.0 Talk. 5.30 Talk. 7.0 Dramatic or Mu ical Information. 6.20, Programme of Humorous Items mission of Pictures. 1.30 to 2.25, Three Talks for Programme, followed by Late News Bulletin, Sports by Professor St. Ligon. 0.58, Time Signal. 7.80, Farmers from Voxhans. 3.0, Talk. 8.30, Musical Notes and Concert. 11.0 (approx.), Close Down. Evening Concert relayed from Warsaw. 9.0, Weather Selecti ins. 5,0, Talk. 0.0, Talk. 7.0, Musical or Report and Fofecast, Press News and Announcements Dramatic Programme, followed by Late News Bulletin. CORK, Call 6CK (222 metres) ; 1.5 kW. -8.30, and Sports Results. 9.30, Programme of Dance 9.30 Programme of Dance Music. 31.30 (approx.), Musical Programme of Vocal and Instrumental Music. 10.30 (approx.), Close Down. Close Down. Selections, Pianoforte Solos by Frau Fleischmann. 11.0, National Anthem and Meteorological Report. KAUNAS (2,000 metres) ; 7 kW. -2.80, Fairy Tales, BERLIN (Voxhaus) (475 metres) ; 4 kW. 7.55 a.m., 11.15 (approx.), Close Down. Songs and Music for the Children. 8.0, Programme Chimes Relay from the Garrison Church at Potsdam. for Young People. 3.30, Talk on Hygiene by Doctor 8.0 a.m. Morning Recital of Religious Music, CRACOW (314 mettes) ; 1.5 kW. -9.15 a.m. to 10.45 Jurgelionis. 4.0, Talk by J. Ardickas on Economics Vocal and In trumental Items and Address, followed a.m., Sacred Service relayed from a Cathedral. 10.58 and the Life of the People. 4.55, Weather Report by Chimes Relay from Berlin Cathedral. 10,30 9.m. a.m., Fanfare Relay from the Church of Notre Dame, and Forecast and News and Announcements. 5.0, (ápprox.), Concert of Popular Music. 1.0, Elementary followed by Time Signal and Weather Report and Talks in the Polish and the Lithuanian Languages. Morse Lesson, by Hang W. Priwin. 1.30 to 2.25, Pro- Forecast. 11.10 a.m., Orchestral Concert relayed from of Agricultural Talks. 1.30, Practical Hints the Philharmonc Hall, Warsaw. 1.0 and 1.20, Talks gramme metres) ; 4 kW.- Programme Sor the Farmer. 145, A Weekly Review of the Market for Farmers. 1.40, Agricultural Bulletin by Dr. St. KÖNIGSBERG (280 Lecture on Report of Weather Conditions. relayed by Danzig (465 metres). -8.0 a.m. (antes less and Weather Conditions. 155, an Agri- Wasniewski. 2.0, with Vocal and Instrumental cultural Topic. 2.30, Programme of Fairy Tales for 2.15, Concert of Orchestral Music by the Ph harmonic only), Sacred Recital Musical Selections. Orchestra, relayed from Warsaw. 0.0, Miscellaneous Items and Address. 10.0 a.m. (KiMivaberg only), Children. 3.0, Talk. 3.30, 8.0, Weather Conditions and Forecast. 10.5 a.m., Musical Talk. 8.80, Calk. 7.0 (approx.), Musical or Dramatic Items. 6.20. Talk. 0.56. Time Signal from the The International Programme followed by Weather Report and Fore- Observatory. 7.0, Fanfare relayed from the Church Programme. 1155 a.m., Pawn by Bulletin. Time Signal,Signal followed by Meteorological Report. LO, cast, Late News Bulletin and Sports Results. 9.30, of Notre Dame, ollowed Sports 7.30, Spanish Lesson A Chess Talk P.'S. Leonhardt. 2.0, Music Programme. 3.1.30 - ( approx.), Close " La Créche de Noël Cracovie," rendered by a Dance Kurt Metze. of " Gas - Down. Students' Choir, relayed from the Hall of the Cracow for Beginners by 7.0, Relay : Zell and Industrial Museum. 9.0, Programme from Warsaw. parone" Operetta in Three Acts by F. 1.5 kW. Relay of Concert .rom the Pavillon Restaurant. Richard Genée, Music by C. Millöcker. Conducted by BERN (407 metres) -9.30 a.m. to 10.30 9.30, produced by Kurt followed a.m. Sermon. 12.0 Noon, Time Signal and Weather 10.80 (approx.), Close Down. Carl Hrubetz and Ling, and Forecast. 12.5, Concert. Programme. by News Bulletin and Sports Notes and Programme Conditions of Dance Music. 1130 Close Down. 0.29, Time Signal and Weather Conditions and Fore- DUBLIN, Call 2RN (431 metres) ; 1.5 kW.-8.30, (approx.), cast. 7.0, Lessing Programme. Dramatic Rerresen- Programme relayed from Cork. Soloist Concert : tation of a Scene from "Nathan, the Wise " by Sonata for Violin and Pianoforte rendered by Mr. LAHTI (1,504 metres) ; 35 kW.- Programme also for artistes from the Berne Stadtheater. 8.45, Sports W. E. Brady and Miss G. Sullivan. 11.0, National Helsingfors (374 metres). --8.0 a.m., Relay of Religious Results, Late News and Announcements and Meteor- Anthem and Weather Report and Forecast. 11.15 Service. 9.50 am, General News Bulletin. 10.5 a.m., ological Report. 9.0, Musical Programme. 9.40 (approx.), Close Down. Musical Selections. 10.59 a.m., Weather Report and (approx.), Close Down. Forecast and Time Signal. 3.0. Music by the Station GENEVA (780 metres) 1.5 kW.-9.0 a.m., Divine Orchestra conducted by Erkki Linko. 3.50, Talk. BÉZIERS (158 metres) ; 0,6 kW.- -8.30, Sports Service with Sermon relayed from the Victoria Hall. 4.57, Time Signal and Weather Report and Forecast. Bulletin. 8.45, Concert of the Latest Pathé -art 3.0, Relay of a Concert from the Plainpalais by the 8.0, Musical Programme. 7.10, Concert Programme. Gramophone Records arranged by the Maison Rclin- Suisse Romande Orchestra, cobducted by M. Fernand 7.30, Concert by the Station Orchestra, Legend Minoles at Biziers. 10.30 (approx.), Close Down. Closset. (Dvorak). 7.45, Late News Bulletin in the Finnish and Swedish Languages. 8.30 (approx.), Close Down. BORDEAUX (Radio Sud- Ouest) (238 metres) ; 1 kW. HAMBURG. Call KA (in Morse) (392 metres) ; 4 kW.- -12.30, Selections from the Latest Gramophone Programme relayed by Bremen (273 metres), Hanover LANGENBERG (482.2 metres) ; 20 kW.- Programme Records. 1.45, Close Down. (298 metres), and Kiel (250 metres). 7.25 a.m., also for Aix-la- Chapelle (455.9 metere.), Cologne Time Signal.- 7.30 a.m., Weather Report and Fore- (263.2 metres) and Münster (265.5 metres). -8.45 a.m., BRESLAU (321 metres) ; 4 kW.-Programme relayed cast, followed by General News Bulletin. 7.50 a.m., Lesson in Self Defence by Dr. Ludwig Bach. 7.5 a.m., by Gleiwits (326 metres). -8.15 am, Chimes Relay Talk on Economic Problems of the Day. 8.0 a.m., Lesson in Shorthand by Hans Molitor. 7.20 a.m., from Christ Church. 1.0, Hints for the Amateur Weekly Legal Talk. 8.15 a.m., Morning Festival. Review in Esperanto of Forthcoming Programmes by Gardener. 1.35, Tam by Adolf Kramer for Chess 10.0 a.m., Talk. 11.55 a.m., The No en International Alfred Dormanns. 7.30 a.m. to 7.55 a.m., Lesson in Players. 2.0, Programme for Children. 2.30, Agri- Tinte Signal. 12.5 (for Hamburg and Kiel), Sunday Esperanto by Alfred Dormanns. 8.0 a.m., Festival cultural Talk. 4.10, Concert of Popular Music. 8.15, Concert. 12. -5 (for Bremen), Sunday Concert by of Religious Music with Address in the interval. Concert with the collaboration of R Benatzky and the Station Orchestra. 1.5 (for Hanover), Gramo- 12.0 Noon, Concert Programme. 1.30, Talk. 3.0, Talk or Josma Selim. 9.0, Weather Report and News and phone Selections. 1.0, Programme for Children. Reading. &30, Concert of Popular Music. 5.0, Talk. Announcements followed by Programme of Dance 10.50 (for Hamburg, Bremen and Kiel), Weather 7.0, " The Taming of the Shrew " : Opéra -Comique Music. 11.0 (approx.), Close Down. Report and Forecast for the North Sea and Baltic. in Four Acts by H. Götz, text following that by 11.0 (approx.), Close Down. Shakespeare arranged by I. V. Widmann, followed by BRUHN (432 metres) 1 3 kW. -3.30, Musical Selec- Late News and Announcements and Light and Dance tions. 4.30, Programme for Workers relayed from HILVERSUM (1,071 metres) ; 5 kW.- 12.10, Lunch- Music. 110 (approx.), Close Down. Prague. 5.0, News Bulletin and Musical Programme time Music by the Station Trio. 1.40, Musical for German Listeners. 9.0, T me Signal, Latest New; Selections. 2.10, Concert relayed from the Concert- LEIPZIG (382 mettes) ; 4 kW-Programme relayed and Announcements and Dance Music relayed from gebouw, Amsterdam. 7.40, Time Signal. 7.42, by Dresden (276 metres). -7.30 a.m., Recital of Organ Prague. 10.30 (approx.), Close Down. General News and Announcements. 7.55, Concert Music. 8.0 a.m., Morning Musical Recital. 12.0 Noon Programme. 10.40 (approx.), Close Down Time Signal. 12.2, Talk. 12.30, Talk. L0, Foreign BRUSSELS (512 metres) ; 1.5 kW.-5.0, Musical Press Review fol.: ivied by Notes on Foreign P dicy. Selections by the Orchestra of the -Armenonville Tea H[IIZEN (300 metres) ; 4 kW.- Transmits from 6.40 2.0 (approx.), Gramophone Selections. 3.0, Literary or Room, Brussels. 6.0, Children's Entertainment, on 1,852 metres. -8.5 a.m., Divine Service. 9.10 a.m., Dramatic ' Programme. 4.0, Muskat Programme. organised by the Children's Theatre under the direct- R, lay of Religious Service. 12.10, Selections by the 5,30, Talk. 6.0,Talk. 8.0, Scenes from " King Lear" A 3'-

www.americanradiohistory.com JANUARY 16th, 1929. WIIW®il®00 69 WOEli of Programmes from Abroad. - Sunday, January 20th. STAMBOUL (1,200 metres) 5 kW.-,3.30, Concert Tragedy by William Shakespeare in a New Trans- Po gramme 4.30, Stock Exchange Quotations and lation by Hans Rothe. followed by News and Announce- Grain Market P'ric.s. 5.15, Selections of Turkish ments and Sports Results and Dance Music relayed Music. 7.30, Weather Report and Forecast and Time from Berlin. 11.80 (approx.), Close Down. AH Times are reduced to Greenwich Signal. 7.40, Concert of Orchestral Music. 9.0, Late News and Announcements. 9.30 (approx.), Close Down. LYONS (Radio Lyon) (291 "litres) ; 1.5 kW. 7,80, Mean Time and are p.m. except The Ratite Lyon " Journal Part_" consisting of News 9TDTTOABT and Announcements, where otherwise stated. (374 metres) ; 4 kW.- Programme Review of the Press and Theatre relayed by Fret-berg (574 metres). -11.0 a.m., Relay mme Notices. 8.0, Concert of Popular Music of Orchestral Concert followed by Latest Gramophone Bred by Madame Ducharne M. Camand (Pianist), Selections. 1.0, Entertainment for Children. 2.0, (Violinist) and M. Testanière ('Cellist) : Selections PARIS (Radio Paris), Call CFR (1,789 metres) : 15 Talk or Reading. 2.80, Musical Programme. 7.15 from "The Nuremberg Doll " (Adam). 10.0 (approx.), (approx.), Concert, Close Down. kW.-8.0 a.m., General News and Announcements Opera or Play followed by Late and Press Review. 8.80 a.m., Physical Culture News and Announcements and Sports News. 10.30 Lesson by Doctor Diffre. 12.0 Noon, Sermon, followed (approx.), Close Down. MADRID (Union Radio), Call EAJ7 (485 meares); by Festival nf Instrumental and Choral Music. 12.30, 1.5 kW.- Programme relayed by Salamanca (EAJ22) General News and Announcements. 12.45, Popular TALLINN (408 metres) ; 2.2 kW.-5.0, Concert of (405 metres). -2.0, Relay nf Chimes and Time Signal. Concert by the Albert Locatelli Orchestra, with Popular Music. 5.80, 'Talk. 6.0, Concert of Orchestral Musical and Soloist Music. 9.0 Close 2.5, Selection. by the Station Orchestra with interlude by Bilboquet : Selections from " La belle (approx.), Down. Interlude by Luis Medina, Good Friday Incantation Hélène" (Jacques Offenbach). 4.30, Latest Gramo- TOULOUSE (Radiophonie du Midi) (383 metres) 8 from " I'arsifal " (Wagner). 3.89 to 7.0, No Trans- phone Records arranged by ' L'Industrie Musicale." ; mission. 7.0, Chimes. 7.5, Musical Programme. kW.-12,15. Agricultural Programme. 12.45, Concert. News and Announcements in the interval. 8.30, 1.0 Time Signal followed by Concert (continued). 3.0, Talk and Reading. Famous Journeys -Extracts Agricultural Bulletin. 6.45, Gramophone Selections. from Interesting Stories Great Voyages. 1.45, News Bulletin from Le Télégramme, L'Express of 8.30 to 7.30, General News and Announcements. 7.45, and Le Midi Socialiste. Exchange 10.0, No Transmission. 10.0, Chimes and Time Radio Paris 8.0, Quotations ant Guignol. 8.30, Café- Concert and Radio- Grain Prices from Par s sepolied by L'Agence Fournier. Signal. 10.5, Musical Programme. 12.0 Midnight, Paris Music Hall. Station Orchestra, conducted Relay of Chimes, t 11swed Dance Music Programme 8.15 (approx.), News of toe Day from " La Depkche by by Maurice André. In the intervals : News and by Palermo and Le Petit Parisien. 8.30, Concert of Orchestral the Orchestra relayed from the Alkazar. Announcements and Press Review, followed by Music. 12.80 a.m. (approx.) (Monday), Close Down. Notices. 9.10, Concert of Instrumental Music arranged 10.80 (approx.), Close Down. by " L'Association des Commerçants Radio-Elec- triciens du Midi " : Saxophone Solo, Pavane pour une MILAN, MI (504 metres) ; 7 kW. --9.0 a.m., Opening POSEN (343 metres) : 1.5 kW. -9.15 a.m. to 10.45 Infante défunte (Maurice Ravel). Time Signal in the Signal and English Language Lesson. 9.80 to 10.30 a.m., Divine Service relayed from Posen Cathedral. interval at 9.0. 10.15, News from North Africa and a.m. (approx.), Vocal and Instrumental Concert of 11.0 a.m., Time Signal. 11.15 a.m. and 11.80 am., Late News Bulletin. 10,30 (approx.), Close Down. Religious Music. 11.30 cm., Time Signal. 11.35 a.m., Two Talks for Peasants. 11.55 a.m , Programme for Selections by the Station Quartet. 3.5, Variety Peasant Women. 2.15. Symphony Concert relayed VIENNA (520 metres) : 15 kW.- Programme relayed Concert : " la Dame blanche " . Overture (B del - from Warsaw. 4.30, ( approx.) Miscellaneous Items. by Ors: (354 metres), Innsbruck (283 metres), Klagen- dieu), rendered by the Station Quintet. 4.15, Selec- 4.59, Programme for Children. 5.20, Vocal Recital furt (219 metres) and Lins (250 metres). -10.0 a.m., tions by the Tzigane Orchestra from the Fiaschetteria by Wanda Roesslerowtta (Mezzo- Soprano) with Concert of Symphony Music by the Vienna Symphony Toscana. 5.0 to 6.55, No Transmission. 6.55. Opening Professor François Lukasiewicz at the Piano : Aria Orchestra and Soloists. 3.0, Concert of Orchestral Signal. 7.0, Review of the Press. 7.15, Talk. 7.25, from the Opera "The Evangelist " (Kienzl). &0, Music. 8.30, " Nathan the Wise " : a Dramatic News from the World of Sp cet. 7.30, Time Signal. Bulletin of the Catholic Polish Veuth Association. Programme in Five Acts by G. E. Lessing (born 7.35, Opera Relay. In the interval : Sports Notes and 8.20. Relay cf Talk from Warsaw. 6.45, Talk by January 22nd, 1720), produced by Doctor Hans General News Bulletin. 10.30 ( approx.), Close Down. M. H. Busiakiewicz " Silva rerum.' 7.5, Programme Niichtern, followed by Programme of Light Music and of Various Items. 9.0, Time Signal. 9.5, Sports Experimental Transmission of Pictures. 10.80 MOTALA (1,385 metres) ; 40 kW.- Programme also Notes and Announcements. 9.20, Dancing Lesson ( approx.), Close Down. f 'r Stockholm (438 metres), Bodel (1,200 metres), by Mr. Starski. 9.40, Dance Music Programme from Gote'arg (340.R metres), MalmS (229 metres), the Palais Royal Restaurant. 11.0 (approx.), Close VILNA (427 metres) ; 1.5 kW. -9.15 a.m. to 10.45 Osters ind (720 metres) and S tndnall (545.5 metres).- Down. a.m., Divine Service relayed from a Cathedral. 10.58 10.0 a.m., Relay of Divine Service from a Church in a m., to 4.80, Programme relayed from Warsaw. Stockholm. 4.0, Programme for Children. 4.55, PRAGUE (343 metres) ; 5 kW. --8.0 a.m., Concert 10.5e a.m., Time Signal and Relay of Fanfare from the Chimes relayed from Stockholm Town Hall. 5.0, of Religious Music. 9.0 a.m., Talk for Farmers. Church of Notre Dame at Cracow. 11.5 a.m., Aviation Divine Service Relay. 6.5 (approx.) Relay of Play 12.0 Noon, Notes on Trade and Industry. 12.15, Route Notes and Weather Conditions and Report. 'The Wild Duck" (Tbsen). 7.45, Programme of Sociological Talk. 8.30, Concert Programme. 4.80, 11.10a m . Concert of Symphony Music by the Warsaw Choral Music. 8.15, News and Announcements and Talk for Workers. 5.0, Programme of News and Philhar" on c Orchestra. 1.0 to 2.0, Three Agricultural Weather Conditions and Forecast. 8.40, Concert Musical Selections for German Listeners. 9.0, Time Talks. 2.15, Symphony Concert by the Warsaw Phil- Programme. 10.0 (approx.), Close Down. Signal and Late News Bulletin followed by Dance harmonic Orchestra. 4.80 (approx.), Talk in Lithu- Music. 10.30 (approx.), Close Down. anian. 5.0, Gramophone Records. 5.20, Children's Corner. 5.45, Musical Selections on the Zither by MUNICH (537 metres) ; 4 kW.- Programme relayed Professor Witold Jodko. ( by (500 metres), RABAT, Call PTT (414 mettes) : 2 kW. -19.80 to 8.0 approx.), Humorous Augsburg Kaiierala tern (273 metres) Programme. Zither Music by Professor and Here .berg (240 metres). -9.0 a.m., Catholic 2.0, Music Selections by the Station Orchestra. 4.0 820, Witold Morning with to 5.0, Selections of Military Music. 8.I5, " Le odko. &SO (approx.), Time Signal. 7.0 to 10.80, Recital Address. 10.0 a.m.. Relay of mme relayed from Chimes from the Munich Town Hall. 1010 a.m., Journal Parlé," News Bulletin. 8.80. Concert by Warsaw. 7.0, " Intellectual Wireless Weather Chart for Bavaria. the Station Orchestra. At 9.80, in the intervals, Amusements " by M. C. Jablonowski. 7.30, Violin 1.5, Time Recital. Sonatina in C. Major (Franz Signal, Weather Report and Forecast and Review of Sports Talk and Results by M. Barrier. 10.30, Selec- Schubert) Forthcoming Programmes. tions of Jazz Music from the " Chaumière de Rabat." rendered by S. Frenkel (Violinist) and Professor I.. 8.85, Relay of Foreign Urstein (Pianist). Aviation Notes and Weather Stations. 9.20, News and Announcements. 11.0 11.0 (approx.), Close Down. 9.0 (approx.), Close Down. Conditions and Forecast. 9.5, News supplied by the Po ish Telegraph Agency. ROME, Call IRO (444 metres) : 3 kW. -$á0 a.m., 9.20, Police Notes and Opening Signal, followed by Lesson In Sports Results. 9.80, Programme of Dance Music NAPLES, Call INA (333 metres) ; 1.5 kW. the German -8.30 a.m., Language. 9.0 a.m., Recital of Religious Music. relayed front the " Oaza " Restaurant, Warsaw. French Language Lesson under the direction of Pro- 10.30 (approx.), Close Down. fessor Etienne Verdier. Vocal and Instrumental Selections. 9.45 a.m. to 9.0 a.m., Sacred Music Recital. 12.0 Noon, 3.45, Programme for the Children. 4.0, Musical Pro- No Transmission. 18 0 Noon, Opening Signal. 12.5 to LO, Selections by the Station Trio. WARSAW (1,415 metres) ; 10 kW.-9.15 a.m. to gramme. 480, Time Signal. 7.80, News and An- 10.45 a.m., Divine Service Relay from a Cathedral. nouncements. Rep.wrt by 10.ío 4.0, No Transmission. 4.0, Opening Signal. 7.50 the Naples Harbour 4.5 5.80, Concert of Light 10.58 a.m., Time Signal. 11.0 a.m.. Fanfare relayed Authorities. &0, rfime Signal. Musical Pro- to Music. 6.50, News Irons the Church of Notre 8.2, Bulletin and Review of the Press. 7.10, (approx.) Dame, Cracow. 11,5 a.m.. gramme : Selections : from Opera Final Trio from Talk for Agriculturists. General Report on Aviation Routes and Meteorological Report Act V of " Faust " (Gounod), rendered by E. 7.15, Sports Notes and Blandi Announcements. 7.29, Tinte Signal. 11.10 am., Morning Symphony Concert organised by (S)pmno), R. Rotondo (Tenor), and C. Albini 7.81, Talk the Department (Bass), on Topics of the Day. 7.45 "The Daughter of for Education and Culture of the with accnmpaniment by the Station Orchestra. 9.0, the Magistracy of Warsaw. 1.0 to 2.0, Three Agricultural Sports Review. 9.50, Calendar and Regiment " -Lyrical Comedy in Three Acts by Future Pro- Gaetano Donizetti, rendered by the Station Choir Talks. 2.0, Weather Conditions and Forecast. 215, gramme Announcements. 10.0 (approx.), Close Down. Symphony Concert relayed from the Warsaw Phil- and Orchestra with Soloists. In the interval : Short harmonic Story Reading. 9.50, Latest News from the Press. Hall. 4.30, Talk. 4.55, Talk. 5.20, Popular PARIS (Eiffel Tower), Call FL (1,488 metres) 5 kW.- 10.0 (approx.), Close Down. Concert. 0.0, Various Items. 0.20, Talk. 6.45, News 7.50 a.m., Time Signal on 32.5 metres. 9.25 a.m., Bulletin. 8.58, Time Signal. 7.0, Talk by C. Jablo- Time Signal on 1,488 nowsky on Intellectual Amusements. Violin metres. 5.0, Pasdeloup Concert Call (19.56 7.80, Relay. 7.10 to 7.20, Meteorological SCHENECrADr, 2XAF metres) ; 30 kW. Recital by Mr. S Frenkel with Professor L. Urstein Report. 7.5 -4.0, Divine Service Relay. 6.30, Peerless Re " -o- ( approx.), " Le Journal Parlé par T.S.F.," consisting at the piano : Nocturne and Tarantella (K. Syz:nan- of Talks on Hygiene, Police ducers, Programme from New York. 9.0, Adj n) s owski). 9.0 Report on Aviation Routes and Weather History, Sports Bulletin for Men by Doctor Parkes Cadman, relayed and Racing Results from " Paris Sport." 7.56, Time en Conditions and Forecast. 9.5, News Bulletin from the Signal on 32.5 metres. New York. 10.30, Violin Recital by Arcade Birken- Polish Telegraph Agency. 9.20, Police Announcements 8.0, Musical or Dramatic tu Iz, relayed from New York. Stetson Programme. 10.28, Time Signal on 1,488 metres. 11.0, Parade: and Sports Notes. 9.36, Programme of Dance Music The American Legion Band from Boston. Mass. relayed from the" Oaza " Restaurant. 10.80 ( approx.), 11.30, The Acnustican Programme, relayed from New Close Down. PARIS (Petit Parisien) (338 metres) 0.5 kW. -8.45, York. 12.0 Midnight, The Old Company's Programme New Gramophone Records. Talk. 8.5), 8.55, News relayed from New York. 12.30 a.m. (Monday), ZURICH (489 metres) ; 1 kW. -10.0 a.m., Musical and Announcements from the Press. 9.0, Orchestral Relay of Programme from the Capitol Theatre, New Selections. 3,0, Music by the Castellano Orchestra Concert with the collaboration of artistes from the York. 2.0 a.m., Talk on " Our Government," by the relayed trom the Opéra and Carlton Elite Hotel. 8.30, Time Op ra- comique. Selections from ' Grisé - Editor of the " United States Daily," relayed from Signal. 8.32, Protestant Address. ,test lidis "- -Opera (Massenet). News and 7.0, Re 9.25, Announce- Washington. D.C. 2.15 a.m., Atwater Kent Pro- Concert-Artistes : Julius Bácchi ('Cellist), Raffaele ments. 9.80, Programme of Sy nphony Music under gramme from New York. 3.15 a.m., Correct i irne. Teminiello (Clarinettist), Otto Strauss (Pianist) ; the direction of S,mgs Professor Estyle of the Paris Con- 8.17 a.m., Programme by the National Light Opera by Torelli, rendered by Frau C. Müller- Schapicr with servatoire. 10.0, Late News and Announcements. Company. relayed from New York. 4.15 a.m., Experi- Flora Pestalozzi-Hofer at the piano. 9.0, Late News 10.15, Selections of Orchestral Music. 11.0 ( approx.), mental Television Transmission. 4.30 (approx.), Announcements Close Down. a.m. and supplied by the Neue Züricher Close Down. Zeitung. 9.30 (approx.), Close Down. A 33

www.americanradiohistory.com 70 WpNtsoo JANUARY 16th, 1929. Wor1eIlcll

SPftN= GR! D VOL

000

Hints on Regulating and Measuring Voltage. By "RADIOPHARE."

T is now generally appreciated that it is practically by using it, there is a much greater chance of obtaining impossible to design an H.T. eliminator to give an an applied voltage approximating sufficiently closely to exact predetermined output voltage, or series of that desired. voltages, for the reason that certain assumptions -often Many readers will share with the writer a desire to based on what must be largely guesswork have to be know, rather than to guess at, the conditions under made with regard to the output load. For instance, which the valves are operating. Such knowledge, individual valves of the same type seldom have identical while perhaps not essential when the set is working well, characteristics, and even the maximum permissible grid is particularly useful when things are not going as they bias (which, of course, influences anode current) will should, and not the least important feature of the poten- depend to a certain extent on output circuit impedance. tiometer method is that it enables us to make an accu- Fortunately, as far as ordinary valves are concerned, rate measurement of screen grid voltage without any all this is of little importance, as their requirements as apparatus other than a reasonably good voltmeter -an to the value of anode pressure are by no means instrument that nowadays forms part of the. equipment exacting. of everyone who takes his hobby seriously. An exception is found in the screened grid amplifying Measuring Working Voltage. valve ; here the voltage impressed on the outer grid must be adjusted with a fair degree of accuracy, and A suggested method of makin& provision for taking from the fact that current consumption is low, close actual voltage readings is shown in Fig. i (a), from regulation becomes a matter of some difficulty ; where which it will be seen that the resistance of the voltmeter the voltage of the source is considerably in excess of itself forms one of the potentiometer arms ; its value is requirements it will generally be convenient to adopt the easily ascertained by multiplying its rated figure of " potentiometer " method of supply, as described at " ohms per volt " by the voltage at full scale deflection. length in a recent article' in this journal. The value of the other resistor in series with the H.T.

Fig. 1.- Method of measuring voltage applied to screen grid (a) and anode bend detector (b). A simple eliminator circuit, including provision for measuremaat of screen grid voltage, is shown in diagram (c). This system has the advantage, as compared with the supply is then estimated in accordance with instructions use of a simple series resistance, of offsetting to a great given in the article to which reference has already been extent the influence of such factors as variation in valve made. If a correct reading is indicated, the meter is characteristics and consequently the current consumed ; removed and is replaced by a fixed resistor having the same value as the instrument ; this part of the opera- " Dropping Volts," by W. I. G. Page, The Wireless World, tion need present no difficulty, as resistances in a wide November 28th, 1928. range of values, guaranteed accurate within limits close A 34

www.americanradiohistory.com JANUARY rbth, 1929. witpam WwIlt 7r Screen Grid Volts. - ance shown in dotted lines (R,) replaces the meter when enough for our purpose, are now obtainable commer- it is re...oved after taking a reading. cially. It is not always easy to measure the actual main volt- If it is found that the voltage is not sufficiently near age output of an eliminator unless one has access to to that specified, it may be adjusted by altering the special apparatus, but it is necessary to have this know- value of the series resistor (a variable component may, ledge in order to calculate with some accuracy the value of course, be used with advantage), or, in certain cases, of absorbing resistances, however they may be con- it may be possible slightly to vary the total output of the eliminator without introducing any detrimental change in voltage supply to the remaining valves. In cases where a very high eliminator voltage is developed it may at times be found that the resistance of the two arms of the potentiometer in series (which will be determined by that of the arm formed by the meter) will be insufficient, and will allow an excessive flow of R2 current. This is especially likely to happen when the meter is of comparatively low resistance. Fortunately, there is an easy way of increasing potentiometer resistance : if a resistor of a value equal to that of the instrument is connected in series with it, the actual voltage L existing cast be ascertained by doubling the figure indicated. At the same time, the total resistance of the (a) :b) potentiometer will be increased and current flow will be reduced. As stated in the article, " Dropping Volts," it is Fig. 3.- Regulating screen grid ',oltay;e by an adjustable series even resistance. more important to fit a potentiometer feed to an nected or for whatever purpose they may be used. O anode bend rectifier valve Probably the simplest way is to connect a voltmeter and mA LF ó_, when there is a consider - milliammeter in the manner shown in Fig. 2 ; this will ccÑ v i= able excess voltage to be give the desired results provided the voltmeter consumes 2 absorbed ; although this is less current than the valves. The W method of procedure W i- rather getting away from is to insert the milliammeter in the common supply lead, -0 the screened grid valve, a and to note its reading, it being assumed that the valves diagram is given (Fig. Y are operating under normal conditions as to grid bias, (b)), showing how a voltage filament brilliancy, etc. The voltmeter - Fig. 2.- "ensuring %oltage should now be output of an e;iminat,r. measurement may be made connected in the position shown, when it will be noticed when a valve is carrying that an increased current is registered by the milli - out this function. Referring to the diagram, R and R_ ammeter ; now dim the output valve filament by turning are the potentiometer resistances, the latter being that its rheostat till current. is brought back to its former which replaces the voltmeter when a reading is not value. The voltmeter will now indicate the true voltage actually being taken ; R, is the coupling resistance. which will exist when'original conditions are restored by In certain receivers intended to give moderate volume removing the meters and turning the filament rheostat and having circuit arrangements which are not prone to to its former setting. interaction it is possible to feed all the anodes from a common terminal delivering a voltage of from i20 to Use of Series Resistances. perhaps as much as 15o. As far as the H.F. side of It must not be assumed that the simpler series resis- such a set is concerned, it will be unnecessary to use tance method of screen grid voltage reduction has no decoupling resistances of more than a few hundred field of usefulness ; it can be quite satisfactory, par- ohms, in which the voltage drop will be so small that it ticularly if use is made of a good resistance element with may be ignored. If there is but a single L.F. amplifier, continuous or semi -continuous adjustment. This interstage coupling is not likely to give trouble unless method, which is particularly applicable when the volt- the detector is preceded by a tuned anode H.F. stage, age to be absorbed is comparatively low, is shown in and very simple smoothing and voltage- reducing devices Fig. 3 ; diagrams (a) and (b) give, respectively, the con- will often be adequate for the eliminator. However, if nections for supplying one and two valves. In the a screened grid valve (or valves) is used in the H.F. second, R, is the regulating resistance, and R R,, are amplifier, some provision must be made for reducing simply isolating resistances of a few hundred ohms. In screen grid voltage, and it is sometimes convenient to using this method, measurement of applied voltage is include this device in the eliminator. The circuit of not possible, or rather, if we try to do it, we come back this unit may be on the lines of that given in Fig. i (c), to the arrangement of Fig. i (a). The best procedure in which R is the voltage- reducing resistance for the is to choose a variable resistor with a maximum value main anode supply (marked + ), and R R the poten- higher by a fair margin than is likely to be required, tiometer resistances for feeding the valve screen (or and then merely to set its control to the point found to screens) through terminal +,. As before, the resist- give best results. A 35

www.americanradiohistory.com WAT@Ilwo JANUARY 16th, 1929. InOpIlI,

idet.RoiK

.,..- ,_ roa ° rerevit .ú;=.t.t-_. ast , _1 .._ NEWS FROM ALL QUARTERS.

By Our Special Correspondent. More Television Tests ?- Political Broadcasting. -A Programme of Talk.

The " D -G " Returns. syllabus has been an improvement on its to the microphone. When " The Liars " Sir John Reith, who has been taking predecessor, and nowadays there must be was broadcast a year ago its author took a short recuperative holiday in Switzer- few listeners who can conscientiously a tremendous interest in the production, land, returned to Savoy Hill last week. grumble at everything which the talks paying a personal visit to the studio 0000 people lay before them. during rehearsals. 0000 0000 So Talks are Popular! Television. Savoy Hill can be forgiven a chuckle Talks for the Troops. The War Office recently sent a cir- Notwithstanding another of those over the ironical results of a London for which the B.B.C. in which readers cular to the Army Commands in Britain guarded statements newspaper competition shows such a masterly aptitude, I should have been asked how they would fill five extolling the value of broadcast educa- all tion. In consequence Savoy Hill has not be surprised if relations between the minutes at the microphone. Nearly Corporation and the Baird Company were the competitors are anxious to give a already received a visit from a repre- talk/ sentative of the Northern Command strengthened in the near future. 0000 (York), seeking full details of the educa- The B.B.C. repeats its announcement of October last to the effect that an ex- Ambitious Talks Department. tional programme and time -tables. En- received from the perimental transmission through a B.B.C. Not even the Germans, who are prolific quiries have also been Army authorities at Exeter, so it looks as station cannot be undertaken at present, enough as broadcast talkers, could fail but adds that any further claim of im- voluminous- if the canteens will soon ring with the to be impressed by the sheer knows stuff to give provement by the Baird Company would ness of B.B.C.'s Talks and Lectures refrain, " Stobart the the 'em." Let us hope so, anyway. be examined with a view to determining syllabus covering the next three months. 0000 whether the earlier decision should be The compilation of the time -table must modified. have been a big task in itself, while the Henry Arthur Jones. The B.B.C. would hardly do otherwise number of subjects dealt with reveals The death of Henry Arthur Jones has in the circumstances ; meanwhile it a nice appreciation of the exact strength removed another of the older school of should be noted that the decision referred of a camel's back. There is this to be dramatists whose work, like Jerome K. to relates to " an experimental trans- said : in the last two year each talks Jerome's, has proved readily adaptable mission through a B.B.C. station." Other tests can be applied. 0000 Politicians in the Studio. January 22nd is the date mentioned in connection with the proposed microphone debate on De- rating. I understand that the Conservative and Labour Parties have both assented to the B.B.C. sugges- tion that the proceedings should com-

prise a Government speech , of twenty minutes, followed by Labour and Liberal speeches each of the same duration, and concluding with a Government reply lasting not more than ten minutes. It is considered probable that Liberal head quarters will agree to the plan. What the listener thinks about it is another matter. The B.B.C. is assuming that silence means consent. 0000 Smart Work. I hear from Johannesburg that " J.B." is broadcasting the daily bulletins from Buckingham Palace with such prompti- tude that Jo'burg listeners hear the news almost as soon as listeners in Britain. "J.B." picks up the bulletin in Morse RESULTS WITH A HOME CONSTRUCTOR'S SET. -A selection of pictures received from Rugby, which sends out the mes- on a Wireless World instrument at a demonstration given at the exhibition of the it is Southend Radio Society on January 5th. The pictures have not been " re-touched " in sage almost at the same time that any way. being read in the London studio. A 36

www.americanradiohistory.com JANUARY 16th, 1929 pg@00 WOACI 73

AUEN To BUENOS AIRES

A Description of the Short =wave Beam Transmitting Stations. HE telephony service on short waves between turbing in the reception of high -speed telegraphy, is a Nauen and Buenos Aires was opened on- Decem- nuisance also in telephony. But if the same number T ber loth last. Each transmitter has a power of of wires is erected behind the first flat aerial system at 20 kilowatts, while the wavelengths are 14.83 and 15.34 a distance of a quarter of a wavelength, then, without metres. the need for supplying any energy to this second aerial With regard to the design of the transmitting aerials, or connecting it iin any way with the first, the back- some interesting details were made public by several ward radiation is reduced to about one -tenth of its workers of the feletunken Company at the meeting of original value. By suitable connection between the German scientific workers at Hamburg last year. Both two planes the backward radiation can be reduced to stations are constructed as beam transmitters, flat aerials 1 / 2ooth or less, so that it need no longer be con- being used. These, as is shown schematically in sidered. Fig. I, consist of two parallel planes each containing Concentric Copper Feeders. sixteen horizontal aerial wires which oscillate exactly As the transmitting aerial in Nauen had to be placed in phase. In this way an outside the rest of the exceptionally sharply de- large aerial installation, it fined beam of transmitted became necessary to use waves is obtained. The long leads from the trans- complete aerial arrange- mitter itself to the aerials. ment is hung from two The arrangement of these masts 236ft. in height. leads offered at first certain Investigations h a v e difficulties, for neither shown that the use of a radiation from them nor horizontal aerial leads to appreciable energy losses the emission of about three could be permitfed. The to four times more energy Telefunken Company there- than can be obtained with fore made extensive re- vertical wires, though the searches with various reason for this is not yet rig. 1. -A sharply defined beam is obtained by employing Hat methods of transferring known. The arrangement aerials with two parallel planes each containing al tteen horizontal wires whi b oscillate exactly' in phase. Aerial wires are such short -wave energy. of two aerial systems in two shown at a, b represents re..ector wires; c masts and d sup- porting ropes. Leads consisting of con- different planes results in centric copper tubes proved the elimination of " back -radiation." An aerial system themselves to be the best in this investigation. A lead in only.,one plane would, of course, be highly direc- of this kind may consist, for example, of an outer tional, but when receiving over long distances the copper tube of ro cms. (4in.) diameter, containing a signals coming from the two opposite directions inter- concentric copper tube of 3.5 cms. Olin.) diameter. fere with one another. This, while particularly dis- The losses in a lead such' as this, while carrying the A 39

www.americanradiohistory.com Wfire®Ilwo. JANUARY 16th, 1929. 74 Wadca Nauen to Buenos Aires. - from the aerial to the receiving apparatus. Aerial short waves tor which it is to be used, may amount to and reflector can be connected either to condenser some 3 per cent. at loo metres, and 23 per cent. at Cl or to C2. Tuning is then carried out by adjust- 1,000 metres, and they are thus considerably more ing until the signals from a distant transmitter are no satisfactory than leads or parallel wires. With con- longer heard, and then the connections to the concentric leads no radiation densers are interchanged. takes place. Fig. 2 shows One may then be sure that two 'methods, which have the adjustments are at their proved satisfactory, for best for reception. connecting the end of a In the discussion follow- lead of this type to a single ing the various lectures, the °aerial ; in addition, various opinion was expressed by other circuits of similar Prof. Esau that a hollow kind have been examined. mirror, especially if made Special care must be Mai with a continuous metal taken over the energy dis- surface, should give a' tribution in the flat aerial, better directional effect than to ensure that the separate (a) (b) a flat aerial. The engineers wires oscillate exactly in of the Telefunken Com- pany, however, did not phase. Four successive Fig. 2.- Radiation from the aerial feeder is avoided by using two aerial wires in a vertical concentric tubular conductors. Satisfactory methods of aerial agree with this, and said coupling are shown in (a) and (b'. line are connected to a that it was not easy to current -lead similar to a pair of Lecher wires, as is make sufficiently large hollow mirrors for wave- shown diagrammatically in Fig. 3. The figure shows lengths of the order of 15 metres, and that with at the same time that the halves of the aerial wires present -day fiat aerials the directional effect is so sharp directed to the left are connected alternately to the that no improvement in this direction was in any way right and left lead- wires. The reason for this can be necessary.' seen at once from the curve showing the distribu- H.F. Amplification of a Million on Short Waves. tion of voltage on the In conclusion, it should be mentioned that Dr. W. Lecher wire. If all the Runge has developed in the Telefunken laboratories a wires of one side of the receiver for telephony and aerial system were to be high -speed telegraphy on connected to a single lead - short waves. This receiver wire, any two neighbouring provides, in four neutral- aerial wires would oscillate ised stages, a high -fre- in opposite phase, and the quency amplification of radiation from each would about 50o times at wave- annul that from the other. lengths down to io metres. Near the earth the separate It is followed by an inter- systems of Lecher wires mediate- frequency ampli- are brought together and fier giving an amplification coupled to the main power of some twenty thousand lead. times, so that altogether a The coupling between high- frequency amplifica- two aerial wires, one be- tion of about a million Fig. 3. - To prevent two portions of the aerial from longing to each surface, is times is in use. Such high tending to oscillate in been opposite phase, the aorial shown in principle in Fig. 4. amplification has leads are connected alterna- The coil Lt, in the case of shown to be necessary so as tely left and right. Lecher wires are shown at a ; b the transmitter, brings to attain the desired cer- represents aerial wires ; c, of working in the Fig. 4.- Tuning the aerial current distribution on the energy to the aerial sys- tainty and reflector. The coil L Lecher wires; d, voltage tem ; in the case of the re- face of disturbances of all brings ener4+y to the aerial distribution on the aerial system. Tne connections to wires. ceiver " it carries energy kinds. C; and C, can be reversed.

Philips Lamps, Ltd., 145, Charing William Geipel, Ltd., 156 -170, Ber- Cross Road, London, W.C.2. Complete Catalogues Received. mondsey Street, London, S.E.1. Illus- price list of Philips radio products, in- trated leaflet describing the " Rapper " cluding loud speakers, battery chargers, tool for drilling holes in brick, stone, The M -L Magneto Syndicate, Ltd., cement, etc. eliminators, and the Philips all -mains re- Works, ceiver. Victoria Coventry. Illustrated 0000 0000 leaflet (Radio Dept.), dealing with anode converts for high and low tension, hand - S. W Lewis and Co., Ltd., 39, Vic- Crystalate Manufacturing Co., Ltd., driven generators for transmitting sets, toria Street, London, S.W.1. Catalogue Tonbridge, Kent. Illustrated catalogue of rotary transformers and motor generator of N.S.F. components and other acces- " Crystalate " mouldings. sets. sories handled by this firm. A 40

www.americanradiohistory.com JANUARY zóth, 1929. WñTsi(>s 75 Woptcal

VE 1.7.p'

Eton mutual conductance of 0.4 mA. per volt. These results were obtained " British Valves." with ioo H.T. and -1.5 volts grid bias. Reference to the RANGE character- of valves fitted with istic curves will show that, as grid special A filaments that permit current commences at zero grid of their being operated from volts, a negative bias of this order one wet Leclanché type large -capa- will be required. city Moreover, this cell has recently been put into just brings the production working point at by the Eton Glass Bat- about the centre of the straight por- tery Co., 46, St. Mary's Road, Ley - tion of the curve. ton, London, E.io, under the name of a round -section wire. The grid and plate are each mounted on a A point of special interest regard- of " British valve." The filament ing this valve takes single support gripped in the is the sharp bend at 0.21 ampere at 1.4 volts, but the foot of the curve following the valve functions " pinch.'' the reasonably well comparatively long, straight por- at a voltage as low as 1.2, at which The untarnished surface of the " getter " indicates that a high order tion. The inference that can be pressure the current is 0.18 ampere. drawn from this characteristic A valve for of vacuum was achieved before the is that practically every posi- the valve should make an exception- tion is made, the range consisting " getter " was flashed. On test the of ally good anode -bend detector. A H.F., R.C., L.F., and output types. valves proved to be dead hard, not the slightest trace of reversed grid current could be detected. BRITISH VALVE BRIT TYPE R C. SH VALVE WLT, TYPE H.F. H.F. Valve. a. W ¡/, E 16 cc This proved to have a rather á 16 i FILAMENT g a higher A.C. resistance under normal l FILAMENT 0.21 AMP ßT 1.4 V. 1 4 A i 0'21 AMP AT 1.4V. iwi amplifying conditions than is usual 1 2 with valves of this type, but, used iMf 25 in conjunction with a suitable trans- o w z IHHhup, former, good results may be ex- 0 0 D 20 cc m á 0 B ME= MIA pected. With 8o volts on the plate 111111 APF . 8 06 15 0 U and a grid bias c,f minus 1.5 volts, 6111111A 15G the average A.C. resistance was < 0'4 10 i 0 1D á o I/1 O found to be 40,00o ohms, 0'2 and the 5 I 0.2 11i0%ii,11 amplification factor 15, iil.%I.%%M , giving a iiIIGGiiM mutual conductance of o.38 mA. per -6 -5 -4 -3 -2 -1 0 1 2 -6 -5 -4 -3 -2 -1 0 1 2 GRID VOLTS GRID VOLTS volt. This valve should make a good grid detector, and when used Average values under amplifying con- Average values under amplifying con- for this purpose the grid circuit ditions. A.C. resistance, 60,000 ohms; ditions. A.C. resistance, 40,000 ohms ; should be returned to the positive amplification factor, 24 mutual conduct- amplification factor. IS; mutual conductance, 0.4 mA/volt. ance, 0.38 mA/volt. leg of the filament. Grid current commenced to flow with about 0.2 negative grid bias of between 2.5 Owing to the heavy " gettering," of a volt positive grid bias. and 3.5 volts will be required, how- it is difficult to examine closely the ever. In view of this we would ex- electrodes, but in one of the speci- R.C. Valve. pect that the values of H.T. and mens sent in for test there was a The principal function of the grid bias will be fairly critical for small area of clear glass through R.C. valve i3 as an amplifier fol- best rectifying conditions, and it which a glimpse of the internal as- lowed by resistance -capacity coup- would be highly desirable to fit a sembly could be had. It appears ling to the following stage. Under potentiometer across the filament that the electrodes are mounted ver- average amplifying conditions the leads and employ two or three dry tically, the filament differing from characteristics were found to be cells, according to the H.T. used. that usually fitted to modern valves, A.C. resistance 6o,000 ohms, ampli- This will enable very fine adjust- in that a single strip is used in place fication factor 24, resulting in a ment of the grid bias to be made. A 41

www.americanradiohistory.com ;6 WaThe®E0 JANUARY 26th, 1929. Waite). Valves We Have Tested. - of this, however, quite good results mutual conductance o.6 mA. per Needless to say, the A.C. resistance can be expected from the valve, pro- volt. The anode current under these will increase considerably when the vided the impedance in the external conditions will be in the order of valve is employed for this purpose, anode circuit is made sufficiently 5 mA. only. and consequently the anode resist- high. If followed by a transformer As the terminal voltage of the Sac ance should not be less than a one should be chosen having a large Leclanché cells will be greater than quarter of á megohm. primary inductance. The anode current under normal 'amplifying BRITISH VALVE conditions, i.e., ioo volts H.T. and TYPE L P BR TISH VALVE volts grid bias, will be in the TYPE L.F. - 4.5 45 order of 2 lnA., and, as the majority U UU1101)11 Ñ FILAMENT /M s 40 m of L.F. transformers with large pri- 0'21 AMP AT 1.4V. rc 1111i FILAMENT maries will pass this ,quantity with- . 36 021 AMP 1.4V. î e 1111 AWAIM a A' out causing saturation of the mag- 1111110WAVAI l 3 netic circuit, there should not be any 111111 I '.11 25 difficulty in obtaining a suitable 11 /.I /.fI/ 1111 11 z component. Incidentally, this valve á20 20 W 3 EMPAII/I11 11111 G could be employed as an H.F. am- O 15 15 j plifier in a neutralised circuit, and, i /G / O d W 10 10 although the anode current required °0 o % /l1111 1111 5 z /2 < 45 is greater than that generally taken 5 CC iEiliM1111 by H.F. valves, it is considerably -14 -12 -10 -8 -6 -4 -2 0 2 GRID VOLTS 12 -10 -8 -6 -4 -2 0 2 4 less than is usual with L.F. ampli- GRID VOLTS fiers. Used for this purpose, the grid be Average values under amplifying con- should biased to about 4.5 ditions. A.C. resistance, 8,9u0 ohms; Average values under amplifying con- volts negative with ioo volts H.T. amplification factor, 5.2 mutual conduct- ditions. A.C. resistance, 22,000 ohms; ance, 0.6 mA/volt. amplification factor, i l ; mutual conductance, 0.5 mA /volt. L.P. Valve. 1.4 at the commencement it is re- L.F. Valve. The particular function of this commended that a filament rheostat The L.F. valve exhibits charac- valve is as an output valve, and of a few ohms be included in the teristics not generally associated with suitable values of H.T. and L.T. circuit. The amount of resist- with valves of this type. A.C. re- grid bias it will handle a grid swing ance in use can be reduced as the sistance, for example, under normal of about 16 volts without overload- voltage falls.

working conditions was found to be ing. With 'Io volts H.T. . and minus The price of the H.F., R.C. and 22,000 ohms, and the amplification 7.5 volts grid bias, the A.C. resist- L.F. valves is 8s. 6d. each, and that factor ri, giving a mutual conductance was found to be 8,goo ohms, of the output, type L.P., valve

ance. of o.5 mA. per volt. In spite the amplification factor 5.2, and the gs. 6d.

Definitions and Formulie for Students. Masters and Mates, including, in Appen- (1) Applied Mechanics, by G. H. Lewitt, dix A, the arguments for and against the including motion, force and energy, BOOKS RECEIVED. training of deck officers in the Merchant strength of materials, structures, Service in the duties of wireless operators. machines and hydraulics. Pp. 36. (2)+ Pp. 59. Published by H.M. Stationery Practical Mathemc.,ics, by Louis Toft, Office. Price 9d. net. including algebra, trigonometry and men- Everyman's Wireless, by Ernest H. 0000 suration, differential and integral calcu- Robinson. A simple description of the Department of Commerce, Bureau of lus, graphs and some differential apparatus generally required by the Standards, Washington, D.C. (1) equations. Pp. 28. (3) Heat Engines, average man for broadcast reception, Methods for the derivation and expan- by A mold Rimmer, including internal- with practical advice in the choice of sion of formulse for the mutual induct- combu stion and steam engines, steam tur- sets and components. Pp. 248, with 21 ance of coaxial circles and for the in- bines, air compressors and refrigeration. diagrams and illustrations. Published ductance of single -layer solenoids, by Pp. 3Y. (4) Electrical, by Philip Kemp, by Cassell and Co., Ltd., London. Price F. W. Grover (Research Paper No. 16). including electrostatics, magnetism, elec- 38. 6d. net. Pp. 25. Price 10 cents. (2) Mutual in- trolysis, lighting and power, A.C. and 0000 ductance of any two circles, by Chester D.C. generators and motors, and trans- Commercial and Government Radio Shaw (Research Paper No. 18). Pp. 12. mission of power. Published by Sir Stations of. the United States. 1928 Price 5 cents. (3) Receiving sets for air- Isaac Pitman and Sons, Ltd., London. Edition. Pp. 176, and Amateur Radio craft beacon and telephony, by H. Pratt Price 6d. each. 0000 Stations of the United States, 1928 and H. Diamond (Research Paper No. L Edition. Pp. 329. Published by the 19). Pp. 21, with 21 diagrams and illus- W lreless -the Modern Magic Carpet, U.S. Department of Commerce. Price trations. Price 15 cents. (4) The inter- by Ralph Stranger. A popular and non- 15 cents and 25 cents respectively, from national temperature scale, by G. K. Bur - technical outline of the elements of wire- th; Superintendent of Documents, Gov- gess (Research Paper No. 22). Pp. 6. less, especially in relation to broadcast- ernment Printing Office, Washington, Price 5 cents. (5) Design of tuned -reed ing. Pp. 312, with nearly 250 illustra- D.C. course indicators for aircraft radio - tions and diagrams. Published by S. W, 0000 beacon, by F. W. Dunmore (Research Partridge, Ltd., London. Price 3s. 6d. Board of Trade Report of the Depart- Paper No. 28). Pp. 19, with 21 dia- net. mental Committee on Examination of grams and illustrations. Price 5 cents. - A 42

www.americanradiohistory.com JANUARY z6th, 1929. WAa@hom WOrIld 77 ,

f . WonLn

LABORATOiTI_TEìsv

A Review of Manufacturers' Recent Products.

DUBILIER, H.F. CHOKES. were only kin. deep ; as a consequence The makers give the useful range of this Although a single well -designed choke the inside end of the wire in each section choke as 100 to 2,000 metres, and it is will perform satisfactorily on all wave- touches all the turns of the winding on intended as a general purpose or lengths used for broadcasting, including its way to the surface. In our opinion " universal choke. The impedance short waves below 100 metres, there can there is room for improvement here ; not measurements show, however, that the be no doubt that an improvement can only is the insulation of the wire sub - choke resonates at about 600 metres, and be achieved, when the wave band to be jected to unnecessary strain, but the it cannot be used in the anode circuit of received is limited, by designing a choke self -capacity of each section is increased. a valve with tuned grid circuit without specifically for the purnose, and neglect- These objections _would disappear if the risk of oscillation above that wavelength. ing the requirements of wavelengths out- lateral slots were increased in depth side the range of the receiver. For this until they reached the core of the mould- reason, quite a number of firms market ing. two types of H.F. choke, one for wave- Type S.W. (D.C. resistance, 3.6 ohms). lengths between 200 and 2,000 metres, and This choke is intended 'for use ex- another for short waves from 200 down- clusively on short waves, and the makers wards. The Dubilier Condenser Co. give the range as 22.5 to 100 metres. The (1925), Ltd., have carried this principle winding is distributed over the seven still farther and now supply no fewer than slots of the former, and the number of four distinct types for use in broadcast turns in each slot is increased progres- receivers. A standard former is used for sively, giving a conical formation of all four chokes; this fits into a neat winding. The impedance measurements, moulded case which excludes moisture which were only carried down to 90 and protects the windings from damage. metres, show that the choke resonates There are seven slots in the former, at 165 metres when the external circuit though only three of these are utilised in capacity is 8 micromicrofarads. The the type AC choke. It was observed that maximum impedance is 20,000 ohms, and the longitudinal slots used for transferring this falls to 8,500 at 100 metres. the wire from one section to the next 7'ype 12 (D.C. resistance, 10.5 ohms .

There are four different types of Dubilier H.F. chokes, each designed for a specific purpose.

In our opinion the use of the choke should be restricted to the medium broadcast band (200 -500 metres) when excellent results should be obtained. Type 40 (D.C. resistance, 136 ohms). The inductance of this choke is much higher than that of the Type 12. With a circuit capacity of 8 micromicrofarads it is probable that the peak would be raised

well above 1,600 metres. This choke - approximates much more nearly to the requirements of a " universal " choke than the Type 12, and gives the following impedance values :- Wavelength Impedance (metres). (ohms). 200 ... 13,000 500 ... 47,200 Impedance curves of Dubilier Type S.W. and Type 12 chokes ; external capacity 8 micro -mid. 1,350 (resonance) ... 316,000 A 43

www.americanradiohistory.com :tr:x`.

Wapg®Mg JANUARY zóth, 1929. 78 WoEIld

Unless the circuit capacity is of the of the pick -up. This is taken by a com- numerous cases these have been partially come the order of 20 micromicrofarads or more it is pression spring, which can be adjusted overcome, they occasionally to likely to provoke oscillation on the to give any desired pressure on the fore under certain atmospheric condi- 5XX wavelength, but will be quite stable record, the outstanding advantage being Bearing this in mind, the Neo-tions. on the medium broadcast band. the partial removal of friction, thereby phone Radio Manufacturing Co. turned Type A.G. (D.C. resistance, 800 ohms). enabling a medium- powered motor to do their attention to developing a cone which 'This is a special choke intended for use the work otherwise possible only with a was impervious to moisture, did not alter as an aperiodic anode inductance for more powerful mechanism. its shape under varying atmospheric con- coupling H.F. valves. Its total im- The device exhibits excellent workman- ditions, and, most important of all, possessed that rigidity and lightness which is The recognised attribute of all high quality cones. The outcome of many months of research is the production of a seamless vulcanised fabric cone diaphragm which is garanteed to maintain its shape and stiffness under the most adverse conditions. The Neophone loud speaker under review incorporates a 12in. diameter cone - shaped diaphragm of this special forma - tion,, the driving mechanism functioning on the balanced armature principle. The periphery of the cone is virtually free, but, although not actually connected to,

Impedance curves of Dubilier Type 40 and Type A.C. chokes ; external capacity 8 micro -mfd. pedance is higher than the preceding ship, the various parts consisting of types, and the major resonance is well duralumin castings finished with a high above 3,000 metres. The curve shows polish. The weight compensation enables two minor resonances at approximately a longer arm to be fitted than is usual, 400 and 850 metres. Following these and provision is made for adjustment of resonance peaks the curve has a negative the length within small limits, this being slope, and conditions are favourable for achieved by fitting the pick -up carrier on self- oscillation between 400 and 500 and a carriage sliding in grooves. The maxi- between 850 and 1,100 metres. Only three slots of the former are used for is Neophone loud speaker incorporating the winding in this choke. One slot vulcanised cone diaphragm. filled with wire, the other is half -full, and the third contains comparatively few is it is positioned by a circular wooden rim turns. It is evident that each section baffle board 13in. resonating with its own self- capacity, screwed to a small in square. The cone is furnished with a and that, due to the dissimilarity the which takes the form of a size of the sections, the coupling is not swaged edge, to pull the sections into double roll ; the object of this is to im- sufficiently tight of stiffening without one effective circuit. part a certain degree However, if the circuit capacity is high introducing excessive damping. clear Actual tests showed that the reproduc- enough to raise the bottom resonance with 500 there is no reason why the tion compared favourably that of metres in should not be used in an amplifier obtained from the best loud speakers choke ear would pro- designed for 200500, metres and the the same class. A critical Daventry 5XX wavelength only. bably find cause to comment on an appar- dimensions of all four types are Kusha " pick -up arm in which the ent over -emphasis of the middle register The of the pick -up is partially counter - in, x2in. in height, and the price weight due to a slight falling off in amplification fin. X1 balanced by an adjustable spring. end of audible scale. .With is in each case 4s. 6d. at either the the exception of the most expensive types, 0000 mum adjustment allowed is 1 inch, the many loud speakers exhibit this defect, 7¡ and 84in. " KUSHA PICK -UP ARM. length being variable between and as even to -day quite a few receivers " are R. H. Glasscoe, 3 and designed The makers are far from perfect, the slight reduction The pick -up arm has been 4, Water Lane, London, E.C.3, and the for use in cases where electrical in amplification at both ends of the audio specially price is 12s. as a serious reproduction of gramophone records is 0000 scale cannot be regarded preferred to the usual method. It is not defect. housed in a well - essential to construct a separate amplifier NEOPHONE LOUD SPEAKERS. The loud speaker is purpose, as if the broadcast re- In all cone -type loud speakers the finished cabinet which can be supplied for this mahogany. The oak ceiver incorporates a first -class low -fre- shape, substance and construction of the in either oak or 17s. and in a mahogany quency amplifier, it is a simple matter to diaphragm contribute in no small way to model is £3 6d., the One of the the successful operation of the device. cabinet £4 4s. The address of the makers adapt this for purpose. Andrew Street, St. of this device is the The paper cone commonly used pos- is : 9 -10, Little St. principal features W.C.2. method of counterbalancing the weight sesses many defects, and although in Martin's Lane, London, A 44

www.americanradiohistory.com Ir JANUARY 16th, 1929. Wñp@Ilsoo %tfld 79

LO1 W i TYPE or. 333 WITH MULTI- ELECTRODE VALVE

A Low priced. Local Station Receiver of Novel Design and Construction. r ¡j 1HE Loewe multi- electrode valve receivers are by no means new. They have been on the market in Germany now for some years, and their popularity in that country is firmly established. The development and progress of the multiple valve has been recorded from time to time in this journal and also in Experimental Wireless, and our technical readers are already well- informed of the 'general principles involved. The establishment in this country of a speci- magnification valves followed ally equipped factory for the production by a " power " output of Loewe Radio valve. Resistance coupling is employed, and all three receivers has again directed attention to this unique valves, system together with their associated resistances and of broadcast reception, and is arousing consider- condensers, are enclosed able interest in a single bulb, which is ex- among the listening public on account of hausted to the proper degree its reasonable price, of hardness required for and in technical circles on account the proper functioning of the valves. of the novel construction of the multiple valve. Loewe multiple valves are made in two types, the Improved Reproduction of High Notes. 2HF, employing four electrode valves for H.F. ampli- Considerable ingenuity has been displayed fication, and in the the 3NF (nieder frequency), or low -fre- arrangement of the elements, with the result that quency amplifier. The later type wiring forms the nucleus of is short and stray capacities are reduced to a mini- the receiver under review, and comprises two high- mum ; this results in a great improvement of the reproduction of high notes, as the subsequent tests revealed. The well -known Loewe vacuum condensers and sput- tered metal resistances are employed, and special precautions have been taken to preserve insulation resist- L.S. ance. The bulb is " gettered " but mica baffles are employed to confine the magnesium to the top of the bulb. A note is included to the effect that valves may require " ageing '' for twenty minutes or so before their normal performance is attained. This suggests residual gas, which automatically clears itself after the valve has been running tor a short period with normal H.T. and L.T. volts -quite a normal state of affairs and one which is common in ordinary commercial three -electrode + valves. Actually the individual valve tested was per- 4V. fectly hard and gave its maximum performance from the moment of switching on. It is a matter of no little difficulty to produce a hard vacuum with so much

11 *p absorbent material in the bulb, and the makers are to be congratulated on having overcome the numerous problems presented by this form of construction. With so many of the essential parts of the receiver Equivalent circuit of the Loewe Type O.E. 333 receiver; the three already valves together with their coupling resistances and condensers incorporated in the valve, it is not surprising are assembled in vacuo as a single unit. that the base is unusually neat and compact. It con- A 45

www.americanradiohistory.com 8o NVtpgpo JANUARY 16th, 1929. Wcoilild Broadcast Receivers. - of such a size that it resonated, with the natural capacity sists of a one -piece moulding, and carries, in addition to of the aerial, at a wavelength approximating to that of the six -contact valve holder, an on- and -off switch, a 5GB. mica dielectric tuning condenser, and sockets of the The variable coupling between the aerial and grid aerial and tuned grid coils. The aerial coil socket is coils can be used to improve selectivity, and also pro- mounted on a swivel bearing and carries terminals for vides an excellent volume control which has the advan- the aerial and earth connections ; there is no electrical tage of being sound in theory as well as effective in connection between the aerial circuit and the remainder practice. of the set, and the energy picked up by the aerial is In the instruction leaflet a 90 -volt high- tension battery transferred solely through the magnetic coupling between with tappings at 6 and 71 volts is recommended. The the two coils. On the opposite side of the base to the connecting leads are so arranged that with such a bat- coil holders are to be found two pairs of sockets. tery grid bias as well as H.T. current can be obtained. The H.T. - terminal is connected to a + 71 on the bat- Remarkable Selectivity. tery, and all tappings below this are then negative with One fair is marked for the loud speaker leads, and the respect to H.T. - (and L.T. - ). By inserting the detec- other are joined across grid and filament of the first tor lead in the 6 -volt socket a bias of - I/ volts is valve , and may. be used either for a frame aerial or obtained, and with the remaining grid bias wander plug for gramophone pick-up. When using either of these in the negative socket of the battery, the output valve ace essories the grid coil must, of course, be removed. receives -71- volts. Although this method makes for The tuning condenser is of neatness, inasmuch as the the rotary vane type, is use of a separate grid bat- neatl y constructed, and free tery is avoided, it should be in act ion, while the filament borne in mind that the H.T. switc h is of the quick -break voltage available is reduced type. The valve holder is by an amount equal to the monkled integral with the grid bias. In the case of base, and hard -rolled phos- the go-volt battery, the phor- bronze springs ensure H.T. available is only 82i firm contact with the valve volts. Under these condi- pins. A multiple strand tions we found that, al- cable carries the H.T. and though the reproduction L.T. supply and the ex- was sweet and pure, the tern al grid bias potential. volume was hardly ade- In the circuit diagram the quate for a small room, conneections of the complete even when using an un- er have been redrawn usually sensitive loud in acccordance with the usual speaker. Any attempt to ntion. It will be increase volume resulted in obser ved that the filaments View of underside of moulded base showing mica dielectric overloading of the last valve of th e first two valves are tuning condenser and valve contact springs. with deplorable conse- connected in series, the fall quences as regards quality. of potential across each filament being two volts. This In view of the fact that go volts is quoted as the normal enables a negative bias of 2 volts for the second valve to H.T. on the valve carton, as well as in the instructions, be picked up from the filament circuit and also effects it was thought at first that this must be the limiting a legitimate economy in filament consumption, since value for which the valve was designed, but enquiry at the first two valves are used for voltage amplification the works elicited the information that the H.T. can be the power involved being negligible. The last valve, on safely pushed up to 15o volts provided the grid bias is the other hand, is called upon to deliver power to the correspondingly increased. Accordingly the H.T. was loud speaker, and the filament is designed to work on increased gradually to 120 volts with a bias of ion volts the full 4 volts supplied by the L.T. battery. The total with very gratifying results. Under these conditions filament current taken by the set was fóund to be o.36 the volume was equal to that of the average three -valve amp., the maker's rating being 0.34 amp. receiver of conventional type, and the quality of repro- The first valve functions as an anode bend detector duction was distinctly good. In spite of the employ- with a grid bias of 4 volts. There is no loading of the ment of two stages of resistance coupling with high tuned circuit, and the selectivity of the set is quite values of anode resistance, we could detect no serious remarkable, having regard to the fact that no reaction is deficiency in the reproduction, and even the high notes used. In London, at r¡ miles from 2L0, on a large were particularly well produced. outdoor aerial, 5GB could be received without inter- Of the sensitivity of the multiple valve there can be ference from the local station. The latter station is no question, for without reaction both the Daventry somewhat faint at this distance, but can be brought up 5XX and 5GB can be well received in London. The to good strength by tuning the aerial circuit with a makers stated that the overall amplification is of the variable condenser across the aerial and earth terminals. order of 3,000, and as the receiver is intended as a local Similar results were also obtained by choosing an aerial station set, the factor of safety is more than adequate. A 46

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JANUARY 16th, 1929. WinIl000 Wald 81 Broadcast Receivers. - likely that the internal resistance of the When using a go -volt battery larger type the total consumption of would be sufficient to cause self -oscillation until the H.T. current is 5 mA., about which is well within the voltage had fallen below a useful marking powers of the " standard " small value. capacity cells, but if Further, the increase in battery resistance is offset a 12o -volt battery is used, by and this is strongly recom- the reduction in anode voltage as the battery runs down, mended, one of " intermediate " or " double " capacity and it is extremely unlikely that trouble will be met is advisable. The current will be about 8 mA., through self -oscillation. which might come jest within the powers of a small cell, The price of the receiver, but the larger including royalty, complete type is preferable on account of its lower with multiple valve, but exclusive internal resistance. of coils, batteries, and As the H.T. voltage is increased loud speaker, is £4 ios. (In the Buyers' the margin of safety Guide, which in the matter of back coupling appeared in the November 14th issue, the through the battery resistance price was is narrowed. A test given, due to an oversight, as £4.) The registered showed that 25o ohms was necessary to provoke oscil- offices of the Loewe lation at Radio Co., Ltd., are at 364, Clements no volts, and while this value of resistance Inn, London, W.C.2, and the works might be attained address is 4, Foun- in a small capacity battery, it is un- tayne Road, Tottenham, London, N.15,

LETTERS TO THE EDITOR.

The Editor does not hold himself responsible for the opinions of his correspondents. Correspondence should be addressed to the Editor, "Tae Wireless World," Dorset House, Tudor Street, E.0.4, and must be accompanied by the writer's name and addres'. TELEVISION. of a moving picture. In either case the picture is divided into Sir, -When Mr. Moseley and his friends can produce tele- a number of bands or strips. which vary in vision images depth of colour comparable' in size, quality and cost with the from white to black, according to the particular part of the pictures given by the Fultograph there will be time to grouse picture to be reproduced. In the still picture about these bands can "unfair discrimination." G. M. PART. be about nth inch apart, giving decent definition. Woking, Surrey. If we assume that the dark and light parts of the band or strip may in the extreme case require to be as finely separated into dots as 50 per inch, we have 50x50 -2,500 variations of in- Sir, -In a letter in 7'ke Wireless World, dated December tensity required per square inch of picture 19th, Mr. transmitted, and Moseley talks of possible " prejudice " in the for television we require this 15 times a second, giving B.B.C. dismissal of Television, and states that the B.B.C. 15x2,500 = 37,500 variations per second. " have not Now for a picture said why they rejected television." only one square inch in area we shall want a side -band width [Since Mr. Moseley is connected with the " Television of 37,500 cycles, or 371 kilocycles each side of the nominal Press," it is possible that he himself may be unconsciously " frequency " of the station. With prejudiced the Geneva plan it can't in favour of television !] be none. We should therefore be limited to a picture about If the B.B.C. were to reply to this question they would, one square inch (say 2 inch x¡ inch) if we want as good definition may suppose, have two answers at least. First, " in its as this. present state of development television is of the greatest Perhaps the definition would do rather less than this if we scientific interest, but has no entertainment value whatever "; had a bigger picture. Suppose we consider and secondly, " a sort of cinema development in the direction in which it is show on a picture 4f t. x4ft., then all we can do is to have the most needed could be made as well, or better, over a short " strips " about 2 inches wide ! The definition will be un- ` land -line ' between two adjacent rooms than by ' wireless.' " speakably hopeless. On these lines the writer has worked out They might also add that with the side -band width permissible what would be the side -band width required under the Geneva tc produce a scheme, which allots stations frequencies pictúre 1 foot square, with definition' equal to that of the differing by only 10 kilocycles, it would be physically impossible illustrations in The Wrreleas World. It is over 5,000 kilocycles ! for a single broadcasting station to transmit a television Our transmitter would require as much space in the ether as picture of adequate size and definition, apart altogether from several hundred broadcasting stations. any mechanical difficulties which may yet have to be overcome. This, however, is "all theory," what is (The writer's it like in practice? reason for this statement will be giver later.) The writer was lucky enough to be able to see a demonstration Still picture broadcasting is in rather a different position. during the time the Wireless Show was on. From A system a scientific has been in use for many years on land - point of view it was extraordinarily interesting, as lines (the exact date I cannot a form of remember, but the Daily Mail entertainment it was not. The picture appeared to be worked a service on a private line between their London and divided into some 15 or 20 vertical strips only ; the 'flicker," Manchester offices before the War). With the perfection of far worse than with the earliest cinematographs improved methods of 25 or ZO years of synchronisation and a reasonably cheap ago, rather covered up this defect, but it was still very notice- receiving device (all developed without any strictly " wireless able. After only some ten minutes' demonstration work all by means the writer at of land- lines) there was no particular was distinctly conscious of eye- strain (it is possible that, say, difficulty in adapting . the land -line transmitter to modulate a an hour of steady "looking in " would produce this effect in the wireless wave. The B.B.C. are, I suggest, justified in trying exaggerated form met with in early it, cinematographs, in fact,as to see if there will be a suflicient demand created. As one the flicker is so much worse, the resultant headache, etc., of your other correspondents points out, we can get pictures may be expected to be more acute). The want much better and of definition, cheaper for ld. a dozen in the evening paper; as may be expected from the small number of strips into which and it seems more than probable that after giving the scheme the picture is divided, was very obvious. a fair run for, say, six months or so, the B.B.C. will drop it, The report on the demonstration in 7'he Wireless World which they will be was able to do without incurring any very great really very kind- hearted, as might be expected, perhaps, from expense for " scrapped " plant. a paper devoted to wireless But and kindred subjects. while it is easy to produce a single picture in, say, In order to have entertainment value it seems four or five minutes, than television it is a very different matter to produce a must work at least several hundred tunes as fast as at present, picture 15 times a second, as is necessary to produce the effect perhaps if only one hundred times as fast it might be used on A 47

www.americanradiohistory.com q i ä+^1-171.1kTVrrwtIri-V!' .1 r4-IXI

82 VV p(Ol@RM f ALV UAKY rout, 1929. WUleltd. lnnd -line to reproduce the head of the person spoker to on the For these conditions it can be shown :- telephone with sufficiently good definition to enable the man Ra at the other end to be recognised. In the 'writer's opinion, for Output = (Imaz-Imin )2x reasons stated above, it appears unlikely that it will be satis- Where Ra is the anode A.C. resistance of the valve and factorily transmitted broadcast (possibly wired wireless " (Imax - Imin ) is a measure of the anode current swing when might be a solution). the valve 'si in service. any case, in a great deal of In the direction which very Ima, and Imi may be . estimated by setting down on a progress seems called for before television is more than a separate piece of squared paper (as in the figure) a skeleton scientific toy, is a very great speeding up and increase in the anode current -anode voltage curve derived from the curves pub- number of elements of pictures that can be transmitted per lished. (It is convenient to do this since such a' graph facilitates second. It is not known how fast the 'existing light- sensitive further investigation if this is required. ) cells, etc., will work, but it may be, necessary to find some In the figure, A and B are two points taken for E, =O entirely new method of dealing with this, and with " scanning " from published curves of a large -sized power valve at plate the picture (cathode rays have been suggested). But the voltages of 150 and 100. experimental work still to be done before television is of I x is given by trie point where the line CD, whose slope " entertainment value " would appear to be an extension of is 2lta cuts the curve AB. The position of CD can be fixed Baird's own work for many years past, for which a ''wireless " because an anode current, or a grid bias, for Eamax is always trausmission is quite unnecessary. C. R. COSENS. recommended by the manufacturer. Cambridge. In this example the Ea max was 200 v. and the bias advised is such that the plate current is 23 mA. (In practice it is

DIODE DANGERS. Sir, -We have read with interest the article by Mr. H. F. Smith in your December 12th issue entitled " The Distortionless Diode," and, in view of the apparent interest which is being taken by amateurs in this type of circuit, we feel that a word should be put in concerning the type of valve to be used with this method of detection. As a certain number of experimenters may be adopting this form of circuit, we feel that it is important to point out that the valve used for this purpose is operated under extremely severe conditions. , A positive voltage of 101 volts, or even more in some cases, on the grid of a valve would often result in the production of a very large electron emission, and may in many cases have the effect of running the valve under practically total emission conditions. We should like, therefore, to stress the advisability of using a valve designed normally to operate under severe conditions unless the grid polarising voltage is maintained at a comparatively low value. With small valves of types designed for broadcast receiving purposes, where only up to about 5 or 6 milliamperes maximum of anode current is drawn from the filament in normal practice, an attempt to increase this to 20 or 30 milliamperes, continuous drain, as might very well be occasioned when using the same valve as a diode detector, must have a detrimental effect on the life of the filament. Although it has been pointed out elsewhere that this type of sometimes convenient to draw first any line C'D' of the required circuit abolishes the H.T. battery for the detector valve, we slope and move CD along parallel to C'D' until it cuts the think it should be made clear that the large grid current occa- vertical through Ea max at the required point.) sioned by applying a considerable positive voltage to the grid The permissible value of Imi, will be from 0.5 to 5 mA. for would in some cases rule out the use of dry batteries for this most power valves at present available. In any case this figure purpose, otherwise the impression might be obtained that the will be very small compared with I ax, and for a first approxi- normal grid bias battery, reversed, could always be employed mation of the output will not greatly affect the result. for the diode detector circuit. J. H. MARRIOTT. Thus, if we assume in the example of the figure that Imin is London, W.C. The General Electric Co., Ltd. 1.5, we have 1770 Output = (0.0495-0.0015)2x 1 watt approx. It is thus an easy matter to obtain in this way from the OUTPUT OF POWER VALVES. makers' published curves a list showing approximately the .rela- Sir, -The occasions on which the serious- minded listener is tive outputs of all the three- electrode power valves available. called upon to make a comparison between various types of In fixing the grid bias for maximum output the manufac- three -electrode power valves is now so frequent that it occurs turer has to be certain that his recommended conditions do not to the writer that a brief restatement of one of the recognised permit excessive distortion when the full grid swing is used. methods employed far this purpose might be of service to The distortion to be considered is that due to the curvature of readers of The Wirelexs World. the anode current characteristic ; it will be sufficient here to The object of the method is to make an approximate estima- note that tion (for example, in watts) of the maximum undistorted A.C. Distortion in %- (Im Imean x100 output of the valve. This can be done most satisfactorily from max a full set of plate current -plate voltage curves taken for the Approximately 5% is usually the maximum allowed. various values of grid bias. A useful approximation can, how- The above remarks are, of course, no more than an outline ever, be arrived at from the static curves of the valve as pub- of a subject which has already been dealt with in greater detail lished by the maker The method depends on the theory estab- elsewhere, but it is hoped they are sufficient to help the unini- lished by W. J. Brown (Proc. Phys. Soc., Vol. 36, 15/4/24, tiated to make comparative estimates of the capabilities of any page 218) and others, that with a low value of distortion the valves which may be of interest. L. A BARRY. best load for the valve is twice its anode resistance (impedance). Rugby.

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www.americanradiohistory.com " The Wireless World rr Supplies a Free Service of Technical Information. The Service is subject to the rules of the Department, which are printed below; these must be strictly enforced, in the interest of readers themselves. A selection of queries of general interest is dealt with below, in some cases at greater length than would be possible in a letter.

Excessive Resistance. culty. Referring to the diagram, you will The South Kensington Receiver. 111y receiver is made up in two separate observe that a screen (an addition to the Will you please tell Inc if the South Ken- units; the first, a detector valve with amount of shielding normally required) is sington Museum receiver has been capacity -controlled reaction, and the interposed between the primary loading described in " The second Wireless World," a two -stage resistance- coupled coil Li and the coupling coil L_. L, is, and if' so, refer me to the back num- amplifier. The detector unit, with ber in which it was described? phones connected to the output ter- J. F. B. W. minals, works quite satisfactorily, and This demonstration receiver was reaction effects can be obtained, but described at considerable length in our . when the amplifier is added, sensi- issue of February 16th, 1927. tivity is very poor, and variation of 0000 reaetton capacity has little or no effect. Can you suggest what is H.F. or L.F. wrong? B. R. N. l am undecided whether to make up a We expect that your failure to obtain three -valve receiver with H.F. -det.- reaction will be traced to the use of a L.F., or with a reacting detector and coupling resistance (in the first stage) two L.F. stages. Which do you having an excessively high value. In advise? E. L. D. all probability oscillations will be obtained So much depends on your requirements if you shunt this resistor with a fairly and local conditions that we fear it is large condenser (say 0.0003 mfd.), but this quite impossible to give a definite and addition will produce a considerable helpful answer to your question ; indeed, attenuation of the upper audible fre- the whole subject is still controversial, and quencies, and on the whole we think you pages could be written on the relative would be well advised to use a lower advantages of the alternative arrange- resistance ; there is a distinct tendency Fig. I.- Loosely coupled H.F. transformer ments. Briefly, the set with with tuned primary and secondary H.F. nowadays to follow this plan. windings. amplification will score heavily in point a000 of selectivity, and, if the circuit arrange- of course, the secondary inductance, and ment is suitably chosen, it will Double -tuned Couplings. should be of high not suffer efficiency; it may be from L.F. instability even when used In reading one of my pre -broadcasting convenient to choose a compact and some- with an indifferent eliminator or high - issues of " The Wireless World," I what less efficient winding for L, in order resistance H.T. batteries. The detector - came across a circuit showing a loose - to economise space. For reception on the coupled H.F. transformer with tuned normal 2 L.F. set, on the other hand, will give, broadcast waveband, L, should up to a point, loudèr primary and secondary circuits; need- have about ten turns. signals, and will less to say, this arrangement was be easier to operate. applied to an ordinary three- electrode 0coo RU LES. valve. I have tried it with a screened - Grid Resistances. grid valve, and as results are dis- (1.) Only one question (which must deal with a single specific point) can be answered. Letters In the receiver which I am about to con - tinctly promising, both with regard to must be concisely worded and headed " Infor- struct, a resistance of the grid leak amplification and selectivity, I am mation Department." type, having a value of 100,000 ohms, thinking of incorporating (2.) Queries must be written on one side of it in an the paper, and diagrams drawn on a separate is specified for insertion in series with amplifying unit. Unfortunately, space sheet. A self-addressed stamped envelope must the grid circuit of the first L.F. is restricted, and to get the very loose be enclosed for postal reply. valve. Is there any objection to using _coupling between primary (3.1 Designs or circuit diagrams for complete and receivers cannot be given ; under present -day a wire -wound resistor, which I secondary which seems to be neces- conditions justice cannot be done to questions already have? R. G. Al. sary, the two coils must be well of this kind in the course of a letter. be 44.) Practical wiring plans cannot be supplied This will an H.F. stopper, and, for spaced. Can you suggest .a means or considered. it to be completely effective, it is essential whereby the advantages of this kind (5.) Designs for components such as L.F. that its self -capacity should be as low as of transformer may be retained with- chokes, power transformers, etc., cannot be supplied. possible. Therefore we would strongly out making the amplifier unduly I6.) Queries arising from the construction or advise you not to use your wire -wound bulky? G. S. v. R. operation of receivers must be confined to con- element, which almost certainly will have We are afraid you will find it difficult structional sets described in " The Wireless World ' or to standard manufacturers' receivers. an appreciable self- capacity ; most prob- to keep your H.F. unit within reasonable Renders desiring information on matters ably not enough to be harmful when it is dimensions, but suggest that by dividing beyond the scope of the Inlorma /ion Depart- fulfilling its normal function, but more the primary coil in the manner shown in ment are invited to submit suggestions regarding subjects to be treated in future articles or than is permissible for the purpose to Fig. 1, you will partly overcome the diffi- paragraphs. which it is to be put. A 49

www.americanradiohistory.com 84 71pdsoo JANUARY 16th, 1929. WopIlZ Mirrors ant ? ,rtables. Indoor Aerials. Difficulties of Adding H.F. Why is it that my tianslioitatilt set will Can you give ni, some rire on the erec- My two -valve receiver (" Hartley" de- work anywhere in the house except on tion of an inside aerial? In one of tector with one L.F. stage) gives the sideboard in my dining room? the rooms of uty flat the set worked good signals from the two nearest In this position, signals are so weak well when connected to a wire run- stations, but it is very seldom that I that even the local station (about 20 ning along the picture -rail, but since can receive Continental transmissions. miles away) is almost inaudible, and moving it to another room, signal However, the set is so satisfactory the reaction control becomes impera- strength is so seriously reduced that that I woula prefer not to "scrap' it is quite inadequate. The earth con- it, and would like to add an H.F. tive. de- (In reply to a letter asking for further nections are similar in both cases, amplifying valve. Have you being made to a radiator. This seems scribed a suitable method of pro- information)- cedure in any back number? so, is no in the to prove definitely that the aerial is If There metal used will you please give nie a reference construction of the sideboard, and at fault. D. B. G. am We agree, and think you will find that to it? W. D. M. the house is not steel-framed. I This matter was treated in The a photograph showing in the new position the aerial will be briefly sending you Wireless World for June 27th, 1928. the set in the position in which it found to be running parallel with and in proximity to a steel girder, or We should warn you, however, that the fails to work; perhaps this will give close addition of an H.F. stage to an existing a clue. C. D. H. possibly an electric light conduit em- bedded in the wall. Without a know- detector -L.F. set is seldom an easy Your photograph makes clear what matter -if maximum efficiency is to be seemed at first to be a puzzling problem. ledge of your conditions we cannot give obtained advice, but suggest you -and your circuit arrangement We see that the receiver is placed against any definite happens to be particularly unsuitable for a mirror which forms part of the sideboard. should try another side of the same room; this modification. The glass will have a metallic coating, and or, perhaps best- of all, run the aerial wire 0000 this is undoubtedly absorbing energy from diagonally across the room under the your frame aerial, which is probably built ceiling. Detecting Distortion. o 000 into the back cf the case; consequently it In the interests of good quality, is it really is in close proximity to what is, in effect, Badly Reproduced Sibilants. essential that a milliammeter connected a large sheet of metal. My set gives fair quality, but I am not in aeries with an output valve should 0000 at all satisfied with the reproduction show a perfectly steady reading when H.F. Stopping. of speech. In particular, " a " signals are being received ? I find I attach two circuit diagrams showing the sounds do vint come through at all it almost impossible to prevent occa- anode connections of the detector in well. Does this symptom convey to sional slight variations, even though my four -valve receiver; you will see you any hints as to where I should I satisfy myself with volume that that alternative positions for the H.F. look for the trouble? J. C. S. cannot be called excessive. Although choke are shown. Which is correct? Poor definition of the sibilants is there are fluctuations, I notice that C. C. L. generally a sign that the higher audible distortion does not become apparent The diagrams mentioned are reproduced frequencies are not properly reproduced. unless they are of considerable mag- in Fig. 2. The function of an H.F. choke As far as the set is concerned, attenuation nitude. H. P. C. in a circuit of this kind is mainly to of these upper frequencies may be due to In the ideal amplifier, a milliammeter restrict the application of H.F. voltages excessively sharp tuning or to the use of connected in series with the output of the last valve would remain quite steady, but in practice this desirable state of affairs is, as you have found, extremely difficult to achieve, and providing the fluctuations are not continuous and heavy, we do not COUPLING think you need be perturbed. CONDENSER We notice that you live in a locality TO remote from a broadcasting station, and LF thus assume that your set will, of necessity be of a fairly sensitive kind ; M F.0 although you arrange to eliminate varia- COUPLING tions due to actual signala, even on CONDENSER deeply modulated passages, it is quite TO possible that atmospherics will cause occa- L.F. sional " kicks " of the meter needle. coon Short -wave H.F. Amplification. Can you glee me a hint to help me in my experimental work with a short- wave H.F. amplifier using a screened- grid valve? I have had some small measure of success, but am surprised to find that the valve goes into oscillation when the grid and plate cir- (al (b) cuits come into tune over a good part of the tuning range. This happens in spite of the fact that all the usual Fig. 2.- incorrect (a) and correct (b) positions of an ¡I F. choke in the anode circuit of a detector valve. precautions have been observed; screening is complete, and all the cir- to the grid of the succeeding L.F. ampli- anode resistances having an excessively cuits are decoupled. E. D. L. fier, and the arrangement shown in dia- high value ; these are the two main It is rather difficult to help you in a gram (a) does little to achieve this end. causes, but there are others. Again, some highly specialised matter of this kind, but The second method of connection (b) is loud speakers do not deal faithfully with we suggest that the most suitable line of infinitely better; you will see that the " s " sounds, and before condemning the attack would be to add a neutralising intervalve condenser is connected to the set, we advise you to make a comparative system. There is no real reason why this junction between choke and coupling test on another loud speaker, if this can should not be used with a screened -grid resistance. be arranged. H.F. valve. A 50

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,1,1. AN D ;.r*.I:_-. RADIO REVIEW (16 rti Year of Publication) ( \\

No. 49'. WEDNESDAY, JANUARY 23RD, 1929. VOL. XXIV. No. 4.

better feeling by undertaking not to accept for The Editor: HUGH S. POCOCK. Listener more advertisements than are necessary, with its Assistant Editor: F. H. HAYNES. other revenue, to cover the total cost of production. Editorial Offices: 116 -117, FLEET STREET, LONDON, E.C.4 Whilst we welcome the establishment Editorial Telephone: City 9472 (5 of a committee lines). having what may be, Advertising and Publishing Offices: perhaps, described as a " watching DORSET HOUSE, TUDOR STREET, LONDON, E.C.4. brief " for the Press, yet we cannot express ourselves as Telephone: City 2847 (13 lines). Telegrams: "Ethaworld, Fleet, London." envious of the task which they have set themselves to COVENTRY : Hertford Street. perform. It will be their responsibility to Telegrams " Cyclist, Coventry." Telephone: 5210 Coventry. see that the menace of The Listener BIRMINGHAM : Guildhall Buildings, Navigation Street. as a publication in com- Telegrams: " Autopress. Birmingham." Tekphone: 2970 and 2J71 Midland. petition with privately owned journals is not increased. MANCHESTER : 260, Deansgate. Without the strict supervision of this committee it Telegrmns: "lane , Manchester." Telephone: 8970 City (4 lines). would seem that the menace would GLASGOW : WI, St. Vincent Street, C.2. be greater by Telegrams: " IliRe, Glasgow.' Telephone: Central 4837. reason of the fact that the B.B.C. undertakes that it PUBLISHED WEEKLY. shall not make a profit, since all surplus revenue from Subscription Rates: Home, 17s. 4d. ; Canada, 17s. 4d. ; other countries abroad, 19s. 6d. per annum. the publication, however great, could be put back into Entered as Second Class Matter at New York, N.Y; the production of the journal. Thus we might see the As many of the circuits aid apparatus described in these pages are covered by patents, readers are advised, before making use of them, to satisfy themselves editorial expenditure soaring and the journal growing that they would not be infringing patents. in bulk week by week in the effort to maintain the balance between revenue and expenditure. The time CONTENTS OF THIS ISSUE. might come, too, when the B.B.C. might desire to give PAGE EDITORIAL VIEWS .. .. 85 the journal away rather than receive payment for it. ONE METER MANY PURPOSES. BY A. L. M. SOWERBY 86 Such a policy would not necessarily tend to reduce the NEWS PICTURES AT SEA .. .. 91 KIT CONSTRUCTORS' NOTES .. .. 92 number of advertisement pages which the paper would CURRENT TOPICS 94 VALVES WE. HAVE TESTED, MAZDA 2 -VOLT SERIES 95 carry, and would certainly not make it a less formidable USEFUL DATA CHARTS (No. 20) ...... 97 PROGRAMMES rival of those journals with which its contents is PROM ABROAD .. . .. 100 NEW APPARATUS 104 expected to compete. THE PHYSICAL SOCIETY'S ANNUAL EXHIBITION , 106 BROADCAST BREVITIES 109 Last week we pointed out that, in our opinion, the LETTERS TO THE EDITOR ,. 110 READERS' case of The Listener was only a single instance of the PROBLEMS ...... 111 incursion by the B.B.C. into active competition with private enterprise. At present the effect which B.B.C. A TRUCE. enterprise may have upon the interests of the teach- ALULL in the storm of opposition against the pub- ing profession is being discussed, and it is suggested lishing activities of the B.B.C. has intervened as that not even the Board of Education would take it upon the result of a provisional agreement between the itself to indulge in so much interference with the machi- Corporation and those representing the interests of the nery of education as is foreshadowed in B.B.C. policy. Press, under which a committee is to be formed to keep Perhaps the recent outbreak may serve to revive the in touch with the publishing projects of the B.B.C. and efforts of the entertainment industry to safeguard them- be given the opportunity of discussing with the B.B.C. selves against encroachment which they have every any new publishing proposals, and also of making repre- reason to fear. In the plans for the new Broadcasting sentations regarding existing publications of the Cor- House we observe that a super studio, with accommoda- poration. tion for i,000 members of the public, is promised. This truce is, we consider, a fortunate development Whether the B.B.C. derives box -office receipts from such of the argument from the point of view of the B.B.C., an audience or not, in either case it would seem to us for it has allowed the new publication The Listener to that this is equivalent to the establishment of a B.B.C. come into existence, and this, in itself, is evidence that theatre or concert hall in direct competition with those the Press are prepared to adopt a tolerant view within privately owned. certain prescribed limits. But it seems to us quite The radio industry, too, can scarcely feel safe against apparent that the duration of the truce is dependent the possibility of awakening one day to find that the entirely on whether the B.B.C. intends that this com- B.B.C. has decided that the manufacture and sale of mittee shall, or shall not, be an effective body. The broadcast receivers is not one of the activities (if indeed B.B.C. has attempted to assist in the establishment of a there are any) denied to them under their Charter. A' 19

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.7flpigIlis@o S6 Mutcl

The Principles Underlying the Design of Shunts and Series Resistances. By A. L. M. SOWERBY, M.Sc. ROBABLY every wireless enthusiast would like to of the same circuit, a possibility that is obviously denied be able to measure the various voltages and cur- to the owner of a single multi -range meter. Those who rents that are of importance in his receiver, and have studied the catalogues of the makers of electrical to make those other measurements that continually measuring instruments will realise that the extra ex- seem to be necessary in the making up, and especially penditure necessary to obtain this convenience is by no in the designing, of a receiver, such, for example, as means. inconsiderable. the of valves, and finding what checking characteristics Ohms and Amperes. variations from the makers' figures of those alleged Relationship between Volts, constants, amplification factor and A.C. resistance, occur Before discussing the method to be used for convert- in practical working. To do all this, however, a very ing a single -range meter into one that can cope with extensive range of meters is .necessary, covering all any measurement for which it is wanted, it is necessary ranges of current from the one or two milliamps in the to digress for a short while into a consideration of plate circuit of a valve up to the quarter ampere or so Ohm's Law, which expresses the relationship that consumed by valve filaments. In voltage measurements exists between voltage, current, and resistance in a a similar range is wanted, beginning with direct -current circuit, for we shall have an accurate reading of the voltage of a occasion to use this law at every step of single accumulator cell, and rising to the R the proceedings. determination of the high -tension voltage, Those who are completely unacquainted or perhaps 200 volts, applied to the plates with Ohm's Law are referred to an article of the output valve of the set. entitled " Volts, Ohms, and Amperes," It is the purpose of this article to show which appeared in this journal recently how a single meter, with the addition of (M4rch 28th, 1928, p. 341), which gives some carefully adjusted home -made acces- a fuller and more elementary exposition sories, can be made to fulfil all these of this law and its applications than can will, and so to take the place Fig. 1. -T h e current possibly be attempted here. We will con- functions at flowing in a circuit such of the six or eight separate meters that as this is given by :- fine ourselves to a mere statement of the current in amperes = brief outline of its pos- would otherwise be necessary to cover all E.M.F. in volts law and a very the various ranges required. In compari- resistanc e in ohms sibilities in practical measurement. son with the possessor of the full range, or r =R If a steady potential difference V is the owner of a single meter that has been applied to the ends of a resistance R, as made adaptable to all these various tasks suffers prac- suggested in Fig. 1, a current will obviously flow tically nothing in loss of accuracy, provided he has through the resistance. The magnitude .of the current carried out the making of the accessories with sufficient will be greater the greater the potential difference V, and care, and that he is not looking for apparatus of the will be smaller for large values of the resistance R than highest laboratory standard. The only advantage that for small. Provided we stick rigidly to ohms, amperes, remains to the owner of a number of instruments is the and volts as our units, and do not permit ourselves to ability to use several meters at once in different parts stray into using megohms or milliamps, the relation- A 20

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JANUARY 23rd, 1929.. Wflpeggo g7 WOpIld. One Meter Many Purposes. - meter cannot be used to measure voltages greater than ship between V, R and the current I will be given, / volt, for if a greater voltage is applied it will be over- whatever actual numerical values of these may be, by loaded. Since a single accumulator cell has a voltage of the equation I = . Expressed in words, the current about R 2, and we practically never wish to measure voltages in amperes is equal to the potential difference V in lower than this, the meter, without additions, is to all volts, divided by the resistance R in ohms. intents and purposes useless as a voltmeter. If we put It matters not one whit whether R is a simple resist- a resistance R, in series with the meter, as in Fig. 3, ance, as shown in Fig. I, or whether it is a composite we can arrange that the bulk of the voltage to be thing made up of several resistances in series, or half measured is dropped across R1, and not more than the a dozen in parallel, or even of a combination of resist- allowable Ì volt is dropped across the meter, under ances, some in series and some in parallel ; provided the which conditions the current flowing through the two effective resistance of the combination is known, its in series will not exceed 5 milliamps. The value of the value may be used for R in the equation of Ohm's Law. total resistance, including that of the meter, necessary Such cases are indicated in Figs. 2a and 2b. to provide a Current of 5 milliamps on 2 volts can be Since the equation I = is a relationship between obtained from equation 3 : R = ohms. R i o. 005 = 400 three things, we can always find any one of the three Since the resistance of the meter is 50 ohms, this leaves provided the other two are known. To do this it will 350 ohms for R and if we make a composite instru- be convenient to rewrite the equation in two new ways, ment consisting of R, and the meter in series, we shall always get a deflection of 2 milliamps for every volt applied. Thus, by the addition of a series resistance, our milliammeter can be made quite readily into a volt- R meter. r, r2 Extending Voltage Range. A voltmeter made up according to this prescripts on l will be very valuable for reading the voltage of sin gle *IV accumulator cells, but will be of no use whatever for reading the voltage of an H.T. battery, for if we conncorm( (a) it across, say, 5o volts, the current that will flow (equ a- tion I) will be 125 milliamps, and the result will be a Fig. 2. -The same law as in Fig. I holds so long as it is understood that R means the total effective resistance of all the constituent damaged meter. But just as the insertion of a se nes resistances r2 and r1, r3. resistance raised the range from Ì volt to 2 volts, 'so t he increase of this resistance to 25 times its former val ue so that each of the other two quantities is expressed will result in increasing the maximum voltage that c an directly in terms of the others. The three forms, which be read approximately 25 times, and the meter will th en will be wanted for reference, are therefore given in the give a reading 5 1 following table of milliamps for 5o volts, or mil li- :- amp for every 10 volts applied (1) To find current I, knowing V and R, I -R We now have a second voltmeter, reading up to 5o volts, (2) To find voltage V, knowing I and R, V =IR. as well as our first, which read up to 2 volts, and it is clear (3) To find resistance R, knowing V and I, R = i that by having a sufficient Converting Milliammeter to Voltmeter. number of suitable resistances, and making them interchange- With these three equations as moral support, let us able so that we can put any now look again at the problem of making one meter one at will in the position of read a number of different voltage ranges, postponing R1, in Fig. 3, we can use the for the moment the question of arranging the instru- one meter to cover any volt- ment to read currents other than those for which it is age range we please. Fig. 3. -The series resist- primarily designed. In the case of a moving -coil ance R, drops a known part vi of the total voltage V ; For the sake of taking a concrete instance, we will voltmeter, sold as a separate the remainder V, is in- assume that the meter which sufficient to drive through we wish to use reads currents instrument, this series resist- the meter a current large up to 5 milliamps, and that it an internal resistance ance is already in place, and, enough to damage it. of 50 ohms. The voltage across the meter when its although it enables the meter maximum current is flowing can be obtained from equa- to be used for reading voltages, it unfits it completeely tion 2 ; R in this case is 50 ohms, and I is 5 milliamps, or reading currents, since the insertion of so high a 0.005 amp., so that V = IR =5o x o. oo5 = o.25 volt. The resistance into the circuit in which is flowing the curre nt meter, then, can be used as it stands in the capacity of to be measured will usually alter seriously the value of voltmeter, reading " 5 " for o.25 volt, and so on, pro the current. If, therefore, we are going to use the instru- rata all down the scale, each twentieth of a volt pro- ment for both purposes, we must buy, not a voltmet er, ducing a deflection of 1 milliamp. The point is that the but a milliammeter, and supply our own external seri es A 22

www.americanradiohistory.com One Meter Many Purposes. - sensitive than it is by nature. The meter must, there- resistance, fitting it in such a way that it is readily re- fore, be chosen in the first place to indicate satisfactorily movable when the meter is to be used for measuring the smallest current that we are likely to want to read. currents again. ` Standard Resistance Required. For extending the range of currents that can be read It is by now becoming evident that we are to be let by means of the meter, the process is a little different. in for a series of accurate measurements of resistance, We have seen that the maximum voltage that can be for this the meter alone will not suffice. We have permitted to exist across the terminals of the meter is and to have complete command of any circuit we 0.25 volt, since a higher voltage than this leads to over- said that out of the three quantities ; the meter the meter. The value 0.25 was obtained, it must know two loading in to measure current, so that will be remembered, by multi- itself puts us a position either of voltage plying the current flowing, I, it remains to us to acquire a standard Theoretically, it is not of by the resistance of the meter, or a standard of resistance. of these we elect to add R. If we want to measure the slightest consequence which MAIN to our equipment, but in practice a standard of voltage CURRENT current up to 5o milliamps 11 of a cell " giving a we must, therefore, arrange has to take the form " standard this current flowing known voltage. This is rather an expensive item and, that with the voltage the voltage drop across the in addition, is only indirectly of use in that meter -terminals, as given by that it gives varies from the standard value as soon as Fig. 4. -By connecting a more than a very small current is taken from it. ' We shunt rl in parallel with the product IR, still does not the meter, the resistance rise above 0.25 volt. Since choose, therefore, a standard of resistance instead, for as of the two together is soon as we have added this to our current- measuring decreased. The shunted we have decided that we want meter may then be inter- meter we can measure voltages for ourselves. More- posed in the path of a to increase the current ten heavy current without times, we have no resource but over, standards of resistance of accuracy amply high developing voltage enough for our present purpose are not expensive, and enough to drive a danger- to decrease R, the resistance ously large current may be used with reasonably large currents without through it. of the meter, ten times, for this is the only possible way varying appreciably from their nominal value. Since the first task that we shall have to undertake of keeping. the product IR unchanged. with the aid of this resistance is the measurement of This reduction of the resistance of the meter is accom- voltage, since, source of voltage plished, not by disembowelling the meter and rewinding and further, the that we shall use will be the accu- the coil, but by the much simpler process of connecting mulator cell, the of in parallel with it a subsidiary resistance, known as a value this resistance must be so chosen " shunt," in the manner shown in Fig. 4. To reduce R that, the total resistance of meter and shunt in parallel to when put in series with (STANDARD) 11(rl the meter a 2 accu- exactly one -tenth of that of the meter alone, and so to and -volt the maximum current that can be read ten times, Mil mulator, the current taken is multiply just about the maximum the shunt itself must have a resistance of one -ninth of current that the meter will that of the meter. In general, if we wish to multiply 6 VOLTS read. Equation 3 helps us the current n times, the shunt must have a resistance of here ; the value of resistance times that of the meter, and the combination of 2' 5.-The circuit em- must be not less than it -Z ployed for adjusting the shunts precisely the re- meter and shunt will then. have a joint resistance of .. n quired value for higher where I is the largest current current ranges. that the meter reads. If this of that of the meter alone. This fact should be noted, is io milliamps (or o.oio as we shall have occasion to make use of it several times application of these general remarks. amp.) the resistance must not be less than 2 200 in the practical 0.010 - Shunts for Extending Current Ranges. ohms ; if it is 5 milliamps, not less than 400 ohms, and Another way of looking at the effect of a shunt multi- so on for other values. Suitable resistances can be ob- plying the range ten times is to consider that it has to tained from Messrs. Pye, Granta Works, Cambridge ; carry exactly nine -tenths of the current, leaving only one - their " Educational Quality " is amply accurate enough tenth to pass through the meter ; on this basis the reason for our purposes, and costs about seven or eight shillings. why the shunt must have a resistance one -ninth that of Messrs. F. E. Becker and Co., 17, Hatton Wall, E.C.r, the meter is perhaps clearer. make similar resistances, or they can be obtained from Just as a number of different voltage -ranges can be any dealer in scientific apparatus. An accuracy of not covered by using a number of different interchangeable worse than about 0.5 per cent. will be good enough, and series resistances, it is possible to arrange for as many though a higher accuracy than this can be obtained, it different current -ranges as may be desired by employing is not worth paying for, since it will make no difference different shunts, those for the higher current -ranges having to our final results, for the method we are going to em- the lower resistances. But although we can thus shunt ploy is only accurate to about i per cent. away unwanted current from the meter, and so measure It is also absolutely essential to find out from the currents greater than can be dealt with by the unaided makers of the meter to which the shunts are to be fitted instrument, there is no way of making the meter moré the exact value of its resistance, for the system of shunt- A 22

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JANUARY 23rd, 1929. Wk@hoo WOrIl4 89 One Meter Many Purposes.- sary to give 4 milliamps current on 40 volts (it comes making that we shall use cannot be applied unless the out at 10,000 ohms) and wind, from fine resistance wire, resistance of the meter is known. a resistance of a little more than this value. This is The equipment that is required, then, is a milliam- connected in series with the meter and the 20 cells whose meter which covers the lowest current -range that is voltage is known, and the resistance is adjusted as before likely to be wanted, together with an accurate fixed until the scale reading is exactly one -tenth of the voltage resistance of such a value as to convert the milliammeter of these cells. The 5- milliamp meter, in into conjunction a voltmeter reading up to 2 volts or a little more, with this latest resistance, has now become a voltmeter and a knowledge of the internal resistance of the meter reading o -5o volts. itself. With these and a few accumulator cells of fair And so the process continues for as many ranges as size (the ordinary L.T. battery, augmented it necessary by borrowing one or two extra cells) we can make up accurately as many shunts and series resistances as may be wanted. The mode of procedure is, in outline, as follows : First, the standard resistance and the meter are connected in series across one cell of the accumulator, as in Fig. 3, and the current indicated by the meter is noted. The total resistance R in circuit is the resistance of the standard plus that of the meter, and so is known. From equation 2, multiplying this by the current flowing gives the voltage of the cell. Owing to the fact that the total resistance of the circuit is not a convenient round number, the combination as it stands is hardly suitable for permanent use as a voltmeter, for the current will not be a whole number of milliamps for each volt applied, but some inconvenient fraction. The first step is, therefore, to make a new series resistance so that the volts being measured fit conveniently on to the scale division of the meter. Two milliamps per volt will be convenient for the first of the ranges, as this, with A moving -coil meter of the type which is easily convertible by means of external a 5- milliamp meter, will give resistances for reading voltage or current. a voltage range up to 2 volts, which is exactly right for examining a single accumulator cell. may be wanted, the series resistance required We then becoming work out from equation 3 the value of resistance higher for the higher ranges. Later on a method necessary for this, will and from the wire table at the end of be suggested by which the winding and adjusting of this article we choose a suitable gauge of resistance wire, these high resistances can be avoided, commercially and measure off a length which gives a slightly higher obtainable components being used instead. resistance than we expect to require. The standard resistance is then removed and replaced Higher Current Ranges. by this new one, and the accumulator of accurately The making of the shunts necessary for the higher known voltage is again connected. Since the resistance current ranges is carried out in a very similar manner, is too high the meter will give a reading that is too low. but in this case we have to bear in mind throughout the The resistance is therefore lowered, by cutting off short whole process the resistance of the meter itself. If, for lengths, until the meter reads the voltage correctly ; that example, we wish to make a shunt to enable the meter is to say, in the case taken, until the reading on the to measure currents up to 20 milliamps, we proceed in scale is precisely double the voltage found for the accu- this way :- mulator. Whenever we connect this resistance in series Since zo milliamps is four times 5 milliamps, the with the meter, we therefore have an accurate voltmeter multiplying power of the shunt is 4, and its resistance reading o -2h volts. Thus equipped we can proceed must therefore be 1 = of that of the meter. If to the making of a 4 I new series resistance for a higher voltage range--say, this is 50 ohms, the shunt must therefore have 16.67 o -5o volts. For this we take with the newly constructed ohms resistance. Using the wire tables, a piece of re- voltmeter the exact voltage of 20 cells in succession (H.T. sistance wire is measured off to give a resistance of accumulators) and adding all these voltages together we about 18 to zo ohms, thus allowing a margin for adjust- have an exact figure for the total voltage of these 20 ment. cells. We must now work out the series resistance neces- Next, the voltage of each of three accumulator cells A 23

www.americanradiohistory.com Warn Emo JANUARY 23rd, 7929. 90 Wodc1 One Meter Many Purposes. - of resistance some 12 to 14 ohms is taken and connected is mèasured with the o -2h voltmeter already prepared ; in parallel with the meter. When this has been cor- the cells are then connected in series, giving a total rectly adjusted, the resistance of the shunted meter will voltage equal to the sum of the three separate voltages. be i / loth that of the meter alone, or 5 ohms. This, in The shunt is connected in parallel with the meter, and series with the newly standardised resistance R_, gives a the standard resistance and cells in series, as shown in total resistance of (R2 + 5) ohms, and if this is connected Fig. 5, and the current flowing is calculated thus :- to the three cells of known voltage the current resulting The total resistance of the circuit is that of the stan- can be calculated from equation t. Once again the dard resistance (400 ohms in our example) plus that of shunt is adjusted in length until the correct reading, in the shunted meter. When the shunt has been correctly this case one -tenth of the calculated current, is obtained adjusted, the resistance of the shunted meter will be on the meter, which then reads from o to 5o milliamps. exactly one -fourth of that of the meter alone ; that is, By extending this process, making new standard re- one -fourth of fifty, or 12 ohms. This gives a total resistances as required, a whole series of shunts may be sistance of 4121 ohms, and, knowing the exact voltage made to cover all the current -ranges that are likely to of the three cells, and using equation I, we can find be required. The only flaw in the process that the the precise value of the current flowing -it will be about writer has been able to detect, either in theory or through 15 milliamps. We have to make the meter read exactly practical application of the method, is that the accumu- one -fourth of the calculated value ; i.e., some 31 mA. lator cells used have their voltage measured when only a very small current is being drawn from them, and are Sufficiently High Standard of Accuracy. assumed to maintain this voltage unchanged when a Since the shunt has initially too high a resistance the larger current is taken. This leads to an error, but for meter will read, not some 34 mA., but a higher value. comparatively small currents the error is small, being By cutting successive scraps from the shunt the read- certainly less than two per cent. provided the accumu- ing can gradually be brought down to the exact figure lators are in good condition, and neither too freshly required, and when this is achieved the meter may be charged nor run right down. used, by multiplying the scale reading by 4, for measur- TABLE OF RESISTANCE WIRES. ing currents up to 20 milliamps. Resistance in ohms per Yard. It is to be noticed that although the current flowing S.W.C. Eureka. German Silver. is not the same as the calculated value as long 22 1.10 0.52 quite 24 1.77 0.84 as the shunt is wrong, it moves towards and finally 26 2.65 1.26 attains that value as the process of adjusting the shunt 28 .. 3.81 1.85 is carried out, so that no error is introduced by assum- 30 5.58 2.65 is correctly ad- 32 7.35 3.50 ing from the beginning that the shunt 34 10.13 4.82 justed, and basing the calculation of the current flowing 36 ... 14.84 7.06 on that supposition. 38 23.81 11.33 Two alternativesare open to us in making the next 40 37.18 17.70 42 53 56 25.58 shunt ; either we can retain the 40o -ohm resistance, and 44 ... 83.66 39.87 increase the voltage applied in order to obtain larger 45 ... 108.6 51.75 currents, or we can use the shunt already made to stan- 46 ... 148.8 70.9 dardise a new and smaller resistance. The former pro- 47 ... 214.3 102.2 cess generally means having recourse to the H.T. bat- In making shunts for ranges over some 200 milli - tery, and this, even if consisting of accumulator cells, amps, it is desirable to arrange to read the voltages of will drop measurably in voltage so soon as a heavy the various cells while actually delivering a current current is drawn. Consequently the second method, by approximately equal to that which will be required when adopting which we can use again the much larger cells finally adjusting the shunt. If, for example, three cells of the L.T. battery, is greatly to be preferred. are to be used to give a current of o.6 amp. through a First a resistance is made that will pass 20 mA. on resistance of to ohms, a resistance of between 3 and two volts ; its exact value can be found from equation 3 ohms should be connected across each cell separately 3, and comes out at too ohms. A length of resistance while taking their voltages, and to ensure a steady wire having a little more than this resistance according value the current should be allowed to flow for some to the wire table is taken, and connected in series with five minutes before reading the voltage. With this pre- one cell and the meter, the latter being shunted for caution, shunts up to 2 amps. may be made up with 20 mA. The current flowing is noted, and, if thought confidence. desirable, the voltage of the cell is taken again. The If the meter used as a basis for all this work is of a total resistance in circuit is then found from equation sufficiently high standard of accuracy, it would even be 3, and that of the shunted meter (I21 ohms in our ex- advisable to proceed in this way when preparing shunts ample) is subtracted ; this gives the exact resistance R2 for lower ranges. It will, however, be appreciated that of the piece of wire. it is hardly worth while to take the extra trouble neces- Suppose the shunt is to make the meter read to 5o sary to fit the shunts with an accuracy of 0.5 per cent. mA. ; the resistance of the shunt will have to be if the meter with which they are to be used is only guaranteed to read within a margin of error of one er = I / gth that of the meter, or about it ohms. IO -I two per cent. Using the wire table again, a piece of resistance wire (To be concluded.) A 24

www.americanradiohistory.com áé65 JANUARY 23rd, 1929. WIlpamo WOpIldt ç. z

Experiments Aboard the " Olympic." JrO make the North Atlantic crossing may possibly and these, the first pictures transmitted from r suggest five days' isolation at sea with little or Rugby, were received from the onset with that same no information concerning current events. Now perfection of definition possessed by the many wireless that but small interest is taken in morse reception it is transmitted pictures which have been reproduced in overlooked that the high power stations regularly these pages. Sailing on the 12th. the first actual reception transmit lengthy news bulletins which are published at sea was arranged during the early hours of the 13th, . in the daily newspapers produced aboard many of our the " Olympic " by this time being about 400 miles larger liners. out. Six pictures were received without a hitch, print- The recent remarkable achievements in the transmis- ing blocks were made, and a large number of illustrated sion of pictures by wire and wireless and picture broad- news sheets printed off, creating much surprise among casting point to the possibility of including topical the passengers at breakfast. Equally successful results illustrations in the pages of the ocean newspapers. were obtained on the 14th, 15th, 16th and 17th, the Arrangements were therefore made early in last month range then having reached 2,225 miles. On the 18th, by the Daily Telegraph to test the practicability the last day of the outward trip, good reception was of the scheme. The Fultograph apparatus, the excel- obtained at 2,800 miles, although the images bore the lent results of which made the whole idea possible, marks of static, To the reader possessing a picture requires a modulated transmitter of sufficient power to receiver these experiments not only reveal the relia- bridge the three thousand odd miles of the North bility of the system at extreme range, but also indicate Atlantic. This presented little difficulty, and by Post channels for many possible developments. Office co- operation the picture signals were applied to the Rugby telephone transmitter which is used for the transatlantic telephony service. Receiving equipment was installed aboard the White Star liner " Olym- pic," and consisted of an almost vertical aerial running down from one of her funnels, a four -valve receiver, and a standard Fultograph. In addition provision had to be made for the preparation of process printing blocks from the pictures as received. Preliminary tests were carried out aboard the " Olympic " during the Picture receiving equipment on the "Olympic." The wireless receiver is a Wireless World "Kilomag Four" adapted on one of Its wave-ranges to suit the wavelength of Rugby. Using night of December 6 -7th, the Daventry range, 5XX was heard outside New York. A 25

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92 Wp@Il®00 JANUARY 23rd, 1929. WorIlcI cc:'ST1T'"

The New Cossor Melody Maker.

How Best Results may be Obtained.

i,.WIRELESS Rip van Winkle, oblivious to de- and wired by the veriest novice. Everything, excepting velopments in the amateur field since, say, 1922, batteries and loud speaker, is included, and there is no would, on resuming his hobby to -day, probably need for such work as drilling or sawing ; the set can be even more intrigued by the way in which the set be built in a living room without any messy. operations, builder's difficulties have been removed than by the as terminals are used throughout in place of soldered technical progress made during the intervening years. connections. Even the boring of holes for wood screws Rit construction is not new, but what changes it has is avoided by supplying a plywood baseboard ready undergone ! Looking through an old copy of The drilled to take the small bolts, by means of which the Wireless,World, dated a few months before the incep- various components are secured in position. tion of broadcasting in this country,. one sees a " bar- gain offer " of a set of parts for making a tuner-coil- Features of the Design. holder, variable condenser, and box-for ¡5. Nowa- Needless to say, the receiver can be wired without days we expect to get all necessary components for a any knowledge of theoretical diagrams, but it will be simple receiver for something less than that, and, thanks interesting to consider the circuit; which is given in to increased demand and production, we are not dis- Fig. I. The aerial is coupled to the grid circuit of the

appointed. - shielded H.F. amplifying valve by an auto -transformer The new Cossor Melody Maker is an outstanding arrangement, and is tapped to a point on the winding example of what may be done, by careful attention to- near its earthed end. Normally the valve is operated details, in producing a kit of parts that can be assembled with a zero grid, but a small negative bias is applied when resistance is included by rotation of the volume- reducing rheostat. The anode coil, which couples the H.F. amplifier to the detector, is

almost equally simple, consisting : as it does of a single -layer winding with two tappings ; the first, at the centre point of the tuned section, is connected to plate of the H.F. valve. A second is joined to H.T. positive, and a few extra turns wound from this point as a continuation of the low - potential end of the coil, serve as a reaction winding. It will be observed that the grid condenser and leak have values respectively somewhat lower and higher than usual. There is but one L.F. stage, transformer- coupled, which probably accounts for the fact that there is no appreciable tendency towards low - frequency instability. It should be possible to operate the set on dry -cell Fig. 1.- Theoretical circuit diagram, showing values of the various components. H.T. batteries of high internal A 26

www.americanradiohistory.com JANUARY 23rd, 1929. WAyd@oo WopIld 93 Constructors' Nit Notes. - An excellent feature of the particular form of capa- resistance without introducing howling ; indeed, the city reaction control is its small effect on tuning, and effect of inserting artificial resistance in the common the operator can take advantage of this in searching H.T. lead had no effect beyond reducing volume. for distant stations. At the time of writing, the state Although matters are so arranged that pitfalls for the of ether congestion is most marked on the lower part novice are almost non -existent, one rath..r serious of the broadcast band, and many stations receivable " snag " was encountered in testing the particular below about 30o metres are heterodyned. Attention receiver under review : it was found that self- oscilla- was accordingly concentrated on reception of trans- tion was produced as the two variable condensers were missions corresponding to dial readings of over 4o brought into tune, in spite of the fact that the reaction divisions. A convenient method of searching is as capacity was set at minimum. This effect was evident follows : Tune in a station at about this setting and on both medium and long wavebands, and it could be adjust reaction for maximum response ; then slowly checked only by dimming the H.F. valve filament to work each dial together towards a higher reading, keep- an extent which reduced amplification excessively. ing them ' ` in step " (as indicated, in the absence of actual signals, by a breathing sound in phones Ensuring Complete H.F. Stability. or loud speaker). Do not trouble unduly about critical adjust- A careful check of connections and measurement of ment of reaction until a transmission to which it is the applied voltages failed to show anything abnormal, desired to listen is heard ; by concentrating on the but brought to light the fact that the metal container tuning dials proper, the advantages of two-handed was not earthed, although there was a connection control are retained, and a signal once tuned in can be between the vertical screen and the earth terminal. brought up to maximum possible intensity by a slight The addition of a wire connected between a screw right- handed rotation of the reaction control without securing one of the angle -pieces of the box and the fear of losing it. common negative lead was found to effect a complete Mention has already been made of the absence of cure ; precautions were taken to ensure a good electrical any tendency towards L.F. instability ; this largely joint by scraping away the enamel from the metal walls accounts for the fact that the quality of reproduction is under both head and nut of the bolt. Although this distinctly pleasing, inclining perhaps towards a slight expedient can be recommended to any users of the set emphasis to the higher musical frequencies. In view who may encounter the same trouble, it should be of the simplicity of the L.F. amplifying side of the pointed out that, when the original design has been thus modified, care must be taken to avoid short -circuits behveen the terminals of phones or loud speaker and any exposed metal work. The selectivity of any set with simple tuning controls and a single -stage H.F. amplifier is bound to be inadequate when it is used in the wipe -out area around a high - power broadcasting station, and, as was only to be expected, interference from 2L0 was a difficult problem when the receiver was tested with an aerial of medium length at a distance of i miles from that the station. With medium Plan view of the receiver, with cover removed, waveband coils in position, signals spread over a large part of the tuning scale, but receiver, it seems most unlikely that it will be respon- it was possible to receive 5GB without any background, sible for trouble, and so comment is unnecessary. and on the wavelength of this station there was no need The fact that actual or incipient L.F. oscillation is to improve selectivity by reaction. Even when the not produced when the set is used with an H.T. battery long -wave coils were subsfituted, there was still inter- with an (artificial) high resistance would suggest that ference, but it could be satisfactorily reduced either by little trouble should be encountered in using a simple using a shorter aerial or connecting the full -sized aerial eliminator for the supply of anolle current. Provision .to its terminal through a small fixed condenser of for reasonably close adjustment of screen grid voltage o.000r mfd. Under conditions less exacting than must be included, and, to be on the safe side, it is these, selectivity was found to be all that could be as well to include a simple decoupling feed scheme to desired. prevent feed -back to the detector grid. A 27

- www.americanradiohistory.com GYFu .

94 Wtishoo JANUARY 23rd, 1929. WopIlc.l

. -llfÌlill11111 C 1J P P f7N T TOPIC.1' Events of the Week in Brief Review.

TWOPENCE -A-WORD WIRELESS. out tests to determine the most suitable as if he were trying to hide the fact that A new Marconi night letter service be- kind of apparatus required, having he owned a wireless set because he had tween Great Britain and New York has regard to the climate and other natural two aerial poles in his back garden. been inaugurated at the reduced rate of phenomena. When a decision is arrived 0000 2d. per word. 0000 at regulations will be issued concerning THE OXIDE -COATED FILAMENT. the type of receiver which the public " The Development of the Oxide- Coated RUMANIA MAKES A START. may use. 0000 Filament " is the title of a paper to be Rumania, after a long period of hesita- read at a meeting of the Wireless Section tion, has finally decided to adopt broad- IF IT HERTZ -KILL IT. of the Institution of Electrical Engineers casting, and it is hoped that a 12 kW. A puzzled young fellow named Merson, on February 6th. The authors are station now under construction at An inquisitive, pert little person, Messrs. B. Hodgson, O.B.E., D.Sc.,

Otopeni, between Bucharest and Ploesci, Said : " Look, Brother Bert, Ph.D., L. S. Harley, B.Sc.(Eng.), and will be working before the end of March. Is it one Kilohert O. S. Pratt, B.A. A provisional 400 -watt transmitter is Or does one say two Kilohertzen ? " 0000 already in operation, and can be heard 000ri TALKING FILMS. daily from 3 to 4 p.m. and from 7 to THE ONUS ON THE LISTENER. The directors of British Phototone, 10 p.m. G.M.T. on 401.6 metres. Accord- Doubt, genuine or otherwise, is fre- Ltd., and French Phototone, Ltd., an- ing to the Plan de Bruxelles the station quently expressed as to whether the un- nounce that an agreement has been signed should be working on 223.9 metres. licensed listener should await Post Office with Messrs. Klaugfilm, a subsidiary of 0000 notification that a licence fee is due. the powerful electrical group, Messrs. SIAM SEEKS A STANDARD. There should, of course, be no doubt in A.E.G. and Messrs. Siemens -Halske A.G., The wireless experimenter will not be the matter, a licence being a legal neces- who have been engaged in the develop- tolerated in Siam, according to a fiat of sity before a set is installed. ment of talking and sound film devices for some years. the Prince of Kambaeng Bejra, Minister A Northwich listener who was recently 0000 of Communications, who explains that all fined for working a set without a licence radio apparatus is banned for the present. pleaded that he received no notice from THE WIRELESS CONSULTING ROOM. Meanwhile the Government is carrying the Post Office. It did not look, he said, A year's trial with the wireless medical service for mariners, instituted by the - Belgian Government, has proved highly successful, according to a report presented at the Antwerp Military Hospital last week. The service permits captains of Belgian vessels to obtain medical advice from certain coast stations, special medicine chests being provided on each boat. 0000 U.S. COMMISSION ASKED TO GO. Privato broadcasting interests in America are urging the abolition of the Federal Radio Commission which is de- clared to have outlived its usefulness'and which a San Francisco paper likens to the mule -" having neither pride of ancestry nor hope of posterity." Ap- parently the Commission refuses to acknowledge the compliment, resolving to defend its claims for prolongation at the next assembly of Congress. 0000 INDEX AND BINDING CASE. The index for Vólume NNIII of The Wireless World is now ready, and copies are obtainable, price 3d. (post free 4d.); from the Publishers, Dorset House, Tudor WATCHING A PICTURE GROW. Visitors to the recent exhibition of the Southend Street, E.C.4. Binding cases for the Radio Society witnessing a demonstration 01 The Wireless World home constructors' picture receiver. Some of the pictures reproduced on this occasion appeared in our volume can also be supplied, price 2s. 6d., last issue. or 2s. 10d. post free.

A 28

www.americanradiohistory.com JANUARY 23rd, 1929. WfinIlsw 95 WopIlc31

VALVES NWAVË

THESE valves are made by the British Thomson-Houston Co., Ltd., at the Mazda valve factory in Rugby, and are backed by The . twelve years' experience in valve manufacture and over 25 years' ex- Mazda Series of 2 =volt perience in making all types of Valves. vacuum lamps. The series under review falls within the 2 -volt class, the there is no sign of reversed grid filament consumption being o. i am- current showing The H.F. 210 valve is primarily that the valve is pere for the H.F., R.C., and G.P. dead hard. types, 0.15 ampere for the L.F. intended for use in neutralised high - frequency amplifiers, The special function of the R.C. valve, and 0.27 ampere for the power - but under certain conditions it can be employed as 210 valve is as an amplifier followed output valve. Similar construction by resistance -capacity coupling, and is adopted for all types in this particu- a detector or first stage L.F. amplifier. Two specimens were tested, and the makers suggest that the anode re- lar class, the filament being an in- sistance in both cases the A.C. resistance was should have a value of 2 verted " V " with a spring support at megohms. A high anode resistance the top to keep the filament taut and slightly lower than the makers' figures, the amplification factor be- demands a rather high battery volt- prevent it sagging on to the grid. age to ing of the same order compensate for the volts The plate and grid electrodes are of as stated, re- dropped sulting in a better mutual conduct- by the resistance, and in ance. Under average amplifying conditions, MAZDA H.F. 210 the A.C. resistance will MAZDA R.C.210

4 be about 32,00o ohms, the . I it and am- FILAMENT FILAMENT plification factor a MAIM= G11.. 23, giving a mutual AMP AT 2 VOLT/ 0 1'1AMR AT 2 VOLT-r 1111 á conductance of 0.72 milliamp. per N volt ; a good showing for a valve of 0.6I7E I/f11I î 0 . I.I this type. These results were ob- z . 235 ¢ %%' 11 no III tained with 120 volts °/5R H.T. and IUUI . -1.5 i pU/a1iI1y f .'II/M volts grid bias. If used as an anode i ç E//// 111111/I%%I j bend detector, a negative bias of 3 03UUf/p I- I%IU/G O .Im//15 W 11I'/.'/Jq to 4.5 volts, according to the H.T., w oa'o o-2IOU/IE1110 %%%AIM O should be applied, and this will lead I.'1/,//II a YW;./Ì 5 a /%%!WA119 o to an increase in the A.C. resistance ó G, WM= Ó ó `5GG -4 -3 1 2 3 to between 50,000 and 6o,000 ohms, 015-2 "5 -2 -15 -1 -05 0 05 1 15 GRID VOLTS /i and under these conditions the ex- GRID VOLTS ternal anode impedance should not be Average values under amplifying con- less than roo,000 ohms. When em- Average values under amplifying conditions. A.C. resistance 32,000 ohms, ditions. A.C. resistance 90,000 ohms, amplification factor 23, mutual con- ployed for grid rectification, it would amplification factor 40, mutual conductance 0.72 mA /volt. ductance 0.4 mA /volt. H.F. 210. the familiar " flattened " type Characteristics at zero grid bias and 100 volts H.T. such cases where 120 volts only are mounted vertically. These elec- Mutual available it would be admissible to Amplifi- A.C. Re- Conduct- trodes are anchored also to a glass H.F. 210. cation sistance Factor. (ohms). ance employ an anode resistance of support at the top, which is kept in (mA. /volt) slightly lower value. position by a stout wire gripped in Makers' Rating .. 20 28,000 0.7 The two specimens tested showed Specimen 1 20 25,000 0.8 the " pinch " at the foot of the Specimen 2 22 25,000 0.88 better mutual conductances than the valve. This method of construction makers' rating In one case the A.C. ensures a rigid assembly and is be wise to keep the H.T. well below resistance as well as the amplification largely responsible for reducing to a zoo volts and return the grid .circuit factor were higher and in the other minimum the rather unpleasant valve to the positive end of the filament. a lower A.C. resistance was -accom- " pong " hitherto associated with Grid current commences to flow at panied with a slightly bigger ampli- high -amplification valves. 0.5 of a volt positive on the grid, and fication. When used as an amplifier A 29

www.americanradiohistory.com { NWir ®Il®00 96 Wall JANUARY 23rd, í929. Valves We Have Tested.- dealing with small inputs, a potentio- specimens tested were higher than with 120 volts on the anode-net meter should be fitted as explained the makers' rating, the amplification terminal voltage of the battery-it above. factors increased proportionately so would be advisable to give the grid The G.P. 210 valve occupies an in- that the mutual conductances were a small negative bias because grid termediate position between the H.F. of the same order. Under normal current commences to flow at zero working conditions, and when used grid volts. As one cell will be too L.F. 215. MAZDA L.F. 215 R.C. 210. Characteristics at zero grid bias and 100 volts H.T. ,n 18 Characteristics at zero grid bias and 100 volts H.T. 30 áa Mutual F LAMENT Amplifi- A.C. Re- conduct- Mutual AMP. VOLTS L.F. 215. cation sistance Amplifi- A.C. Re- á14-0 .15 AT 2 o ante Conduct- Factor. (ohms). (mA/Volt). R.C. 210 cation sistance ance 12 Factor. (ohms). (mA/Volt). ? Makers' Rating 7.0 7,000 1.0 10 f Specimen 1 9.0 8,000 1.1 Makers' Rating 40 86,000 0.47 Specimen 2 7.4 7,140 1.0 Specimen 1 50 90,000 0.55 44 0.53 Specimen 2 83,000 CC O 6 as an amplifier, the average A.C. re- much, it is suggested that a potentio- sistance was found to be about 17,00o meter be connected across the fila- ó ohms, and the amplification factor ment and the positive of the grid cell 2 13, giving a mutual conductance of connected to the slider, thereby 0.77 volt. -12 -10 -6 milliamp. per In the enabling a fraction of a volt to be GRID VOLTS specimen from which the characteris- applied. About 0.5 of a volt nega- tic curves were obtained, grid current tive will be correct under these con- Average values under amplifying con- commenced to flaw at 0.7 of a volt ditions. A.C. resistances 8,460 ohms, amplification factor 7.7, mutual conductance 0.91 mA /volt. MAZDA P. 227 MAZDA O.P. 210 type and the low- frequency amplify- 111 30 éJ g ing valves, and is . F LAMENT F LAMENT appropriately . 7- f +28AMP. AT 2VOLT 01 AMP AT 2 VOLTS Ó termed a general -purpose valve. It tc 2 0 < is difficult to assign to it any particu- ¢u lar function as it is applicable to H.F., 2 mo9 5of 20 z weon L.F., or detector usage, though as a I- 1 N 402 z I/I.C,r F- W detector it give %1%Llrr would probably the 11&(41101 ¢ z- ¢ 30 ¢ best results when employed under 111If ¢ 10 Q 42151 leaky grid conditions. i/.%%Ifl 20 3 Ec- Although the A.C. resistance of the ó 10 .....0170.10111111li ¢O -28 -24GGii -20 - 6 -12 - - -2 -1 0 1 2 GRID VOLTS GRID VOLTS i Average values under amplifying con- Average values under amplifying conditions. A.C. resistance 4,000 ohms, ditions. A.C. resistance 17,000 ohms, 4.15, con- amplification factor 13, mutual con- amplification factor mutual ductance 0.77 mA /volt. ductance 1.04 mA /volt. ditions, but as this may vary slightly positive grid bias, and as no sign of with different specimens, the poten- reverse grid current was to be found, tiometer should be adjusted to give it shows that the vacuum is of a very best results as judged by the ear. high order. For amplification pur- This valve could be used as an anode poses, the grid should be given about bend detector in a receiver for which 3 volts negative bias. a high -impedance valve is specified The L.F. 215 valve is essentially a for this position, in which case the low- frequency amplifier, and is most P. 227. G.P. 210. Characteristics at zero grid bias and 100 volts H.T. Characteristics at zero grid bias and 100 volts H.T. Mutual Amplifi- A.C. Re- Mutual Conduct- Amplifi- A.C. Re- P. 227. cation. sistance ance G.P. 210. cation sistance Conduct - Factor. (ohms). tance (mA /Volt). Factor. (ohms). (mA /Volt). Makers' Rating . 4.0 2,900 1.4 Makers' Rating 13.0 14,000 0.03 Specimen 1 3.85 3.,450 1.1. Specimen 1 15.4 16,700 0.9.2 Specimen 2 4.2 3,600 1.2 Specimen 2 14.0. 15,400 0.91. usefully employed in the first stage grid will require a negative bias of following the detector. However, from -1 to -2 volts, according to in certain cases, and especially where the amount of H.T. used. To obtain only' two valves are used in the set, satisfactory control of the bias, it can be employed to advantage in which may be fairly critical when Mazda P. 227 2 -volt power valve. the output position. A 30

www.americanradiohistory.com JANUARY 23rd, 1929. 97 WOpIlI Valves We Have Tested. - 7.7, giving a mutual conductance H.T. the mutual conductance of the Actual measurements made with of 0.91 milliamp. per volt. two specimens tested were of the the two samples available showed The particular function of the same order as the makers' figures, that their characteristics were very P.227 is as a power -output valve in but in both cases the A.C. resistance close to the makers' specification, receivers required to deliver a rela- was found to be slightly high. One and careful tests for reversed grid tively large electrical input to the valve showed a higher amplification current failed to reveal any soften- loud speaker. ' The maximum anode factor, the other being slightly. ing due to residual gases, indicat- potential is restricted to 120 volts, lower. Grid current commenced at ing that the valves are dead hard. but it will, nevertheless, successfully half a volt positive on the grid in Grid current commences with 0.2 operate large cone -type loud both valves, there being no sign volt positive grid bias, so when bias- speakers and sensitive moving -coil of reversed grid current. They are, ing the valve for amplification pur- instruments at a reasonable volume therefore, satisfactorily evacuated. poses it would be well to arrange which should be sufficient for aver- The A.Ç. resistance and amplifica- this so that the grid swing is wholly age _ purposes, although in cases tion factor under normal operating restricted to the negative side of the where a larger power output is de- conditions of the specimen from zero line. Under normal working sired it would probably be advisable which the curves were obtained is conditions the average A.C. resist- to employ two such valves in about 4,000 ohms and 4.15 respec- ance was found to be about 8,460 parallel. tively, the mutual conductance being ohms, and the amplification factor At zero grid bias and ioo volts 1.0 milliamp. per volt.

USE ..-q1L DA 11 A CHAR 'l,So (Na 20o) Approximate H.F. Resistance of a Coil when Diameter of Wire is Optimum. rirHE D.C. resistance of a coil wound with solid skin factor is approximately equal to the proximity copper wire is given by factor, and accordingly R = Ro [twice skin factor] Ro x2.67x10 -6 = dD approximately, when d is properly chosen. Where R =D.C. resistance in ohms. The Abac. N =total number of turns of wire. D =mean diameter of coil in inches. Abac No. 20 is constructed on the preceding for- d = diameter of wire in inches. mula. It gives R0, the skin factor, and R (which is twice If stranded wire without twist is used the formula the product of the first two quantities). For a solid wire coil we first multiply N by D, as shown in becomes : - N.D the inset, and on the return journey we divide by d', Ro= x 2.67 x 10_6 and so come to Ro, the D.C. resistance. For calculations in the case of stranded wire coils Where d is the diameter of a single strand and n is three multiplying bars are marked off corresponding the of : number strands when the strands are twisted to 3 -, 9 -, and 27- strand Litz. The appropriate bar is together, in Litz as wire, we must multiply this value to be applied by means of a pair of compasses to the d of Ro by 1.02 for 3- strand, 1.04 for 9- strand, and 1.06 scale, so that the lower pointer rests on the actual value for 27- strand wire, to allow for the increased amount of d, and the upper one marks a new point on the d of wire due to twist.' scale, which new point is to be used on the return Resistance to A.C. Currents. journey from right to left. When alternating current is used the resistance in- What this operation actually does is to replace the diameter of a strand by the diameter of the equivalent creases for two reasons ; first, the magnetic field set up by the current forces the current away from the solid wire, which would have the same D.C. resistance : if central part of the wire, so that this portion fails to do thus three strands are used, each of diameter o.oiin., the application of the multiplying bar will give its share, and we get what is called the "` skin " effect ; the The secondly, in a coil the magnetic field due to neighbour- value o.oi7iin. correction required by the twist in ing turns distorts the lines of current flow in each wire, the wire is also included in this operation. The more strands and produces what is known as the " proximity " ' we use the smaller will be the dia- effect. meter of each strand to give minimum A.C. resistance. Hence when d lies near the bottom of its scale a long Hence we may write for the A.C. resistance : - multiplying bar is present to pull it up again, and so R = R0 [skin factor + proximity factor] . a large range wires can ; Both these factors increase as the wire diameter is of be dealt with it would be an extreme case in which the ruler would be found to made larger, but at the same time R0 decreases, so that run off the a certain wire gauge can always be found which will paper. make R minimum. When this best gauge is found the The. Skin Factor. ' Data kindly supplied by the London Electric Wire Co. The skin factor depends only on the product of and Smiths Ltd. the diameter of the wire or strand by the square root A 31

www.americanradiohistory.com 003 -003 150 004 0 04 005 100 -0'05 0'06 90 7 -= 80 0-06 0'07 8 70 0-07. 0.08 9 60 -008 10 009 01 009 50-z 01

BARS FOR 40 15 MULTIPLYING 015 STRANDED WIRE ONLY 100 015 STRAND 27 80 -= 015 30 20 =02 60- 02 50 40 30 0 1 03 9 STRAND 30 0'09 03 0 08 40 20- 15 04 -007 N 15 04 50 x 0 08 =05 O 3 STRAND 10 - 10 HO 005 0'5 0.6 Z 8= 9 70 8 0'8 0.7 6 0 04 80 5 5 O 7 07 0.8 4 90 n 06 0-9 O 0 03 100 3- 09 w 1 fw rÓ 2

500 -0006 z m TURNS N (7 600 0005 , ? . 1 O J 09 TO FIND SKIN FACTOR n 700 08 7 0004 ¢ f RE DIA. FREQUENCY 800 = 0.7 7 8 900 SKIN FACTOR 8 1000 9 -0003 06 10 9 05 10

04 1500 TO FIND H.F. RESISTANCE 15 D,C. RESISTANCE 5 0 0015 03 2.000 SKIN FACTOR 20 RESISTANCE-1 20

3.000 0001 02 30 APPROXIMATE H.F. RESISTANCE OF COIL WHEN WIRE DIAMETER IS OPTIMUM I W ABAC I N9 20

www.americanradiohistory.com J<4NUARY 23rd, 1929. VfilpsIls@o WiopM, Useful Data Charts. No 20.- Using this value in working through the abac, the of the frequency. Accordingly we find it, as the inset D.C. resistance is found to be 1.06 ohms, which is two shows, by performing this multiplication on going from and a half times as great as for the solid wire ; but right to left, and by drawing a tangent to the curve on we gain on the skin factor, which is now only 1.009, the return journey. It is easily seen that the skin and the H.F. resistance is 2.14 ohms, so that we have factor is greater at high frequencies, and that it also improved matters by using stranded wire. goes up as the diameter of the wire increases. The reactance of either coil is found from Abac 6 The last step is to multiply the D.C. resistance by to be 1,260 ohms, or it can be calculated directly twice the skin factor to obtain the A.C. resistance. This [2- f.L =2 -x 106 x 200 x 10- 6= 1,260], and the magni- is done by joining the points already found for R and fication factor at 300 metres is consequently 2.85 the skin factor, and reading off the A.C. resistance on 2.85 the right. -1,260 Examples. for the solid wire coil, and for the 27- strand 2.14 A single -layer coil of solid wire of circular cross - Litz. section is required to have an inductance of 200 micro - As 4nother example, take a coil of 20,00o micro - henrys, and it is decided to make its diameter 4in. and henrys and of solid wire, the paean diameter being loin., its length 2in. We want to design it for 300 metres, the length and thickness also being loin. ; the coil is and to find its resistance at that frequency. to work at 50,00o cycles. The number of turns re- From Abac 17 we find that 43.5 turns are required quired is 47o, and the best wire gauge is 0.0336in. On to give the desired inductance, and from Abac I9'the working through the abac we shall find that the D.C. diameter of wire to give minimum resistance at 300 resistance is H. ohms, the skin factor 1.08, and the metres works out at 0.034in. H.F. resistance 24 ohms. R. T. B. Hence we have N =43.5, D =4in., d= o.o34in. ; and, using these figures in the present abac, we find that the D.C. resistance is 0.402 ohms. The skin factor INTEREST IN PICTURE RECEPTION. comes out at 3.55, and on multiplying twice this figure Components for Making the Home Constructors' by the D.C. resistance Picture we find the H.F. resistance to Rece: ver.' be 2.85 ohms. From correspondence it is avious that picture reception is Now, suppose we wish to use 27- strand Litz instead. likely to prove popular. Questions are being asked concerning From Abac 19 we find the best diameter of strand is making, modifying, and working the apparatus, while na less 0.0042in. We have accordingly N D =4in., than ten manufacturing concerns are definitely busy with the =43.5, parts. Many requests have been made for precise details of the d ------o.0042in., n =27. On applying the multiplying bar less important parts, so that it has become necessary, when to d= o.0042in., we find the new value d= o.o2r2ih. furnishing these sketches, to standardise the present machine in its entirety. In constructing the various pieces, no improvements have been suggested, so that by now one can accept the present design without the risk of having later to introduce modification. In order, moreover, that component parts drawn from various sources may present no difficulty in assembly, all leading dimensions as well as the locations of fixing holes have been decided. As soon as it is known that a number of machines have been completed, some further notes will be given dealing generally with picture reception. Described in the issue of January 9th, 1929.

The Home Constructors' Picture Receiver. Building entails the assembling of components and wiring.

A 33

www.americanradiohistory.com rnn WhAmo JANUARY 23rd, 194 WOO plld.

"411121....- .. . '_...... umi...... PROCRAMMEf FROM ABROAD

BARCELONA (Isa,liu Barcelona), Call EAJI (350.5 a.m., Exchange Quotations. 11.30 a.m., Concert metres) 1.5 kW.-6.0, Exchange Quotations. 8.10, relayed from Hanover (568 metres). In the Interval Sextet Selection. March, Imperial Edward (Sousa). at 11.55 a.m., Time Signal. 12.10, News. 1.40, 815, Relay of Sacred Music from the Basilica de la Exchange Quotations. 2.30, Review of Books. 3.0, Merced. 8.25, Sextet Selections : Selection from Illustrated Music Talk by Dr. Will. Heinitz. 3.80, Lohengrin (Wagner) ; Idilio campestre (Valls) ; Relay of Programme by the Boys' Choir from the St. Hesitation Waltz, Heures suprêmes (Worsley). 8.30, Jacobikirche. 4.80, Request Concert. 5.30, Dr. H. O. Elementary French Lesson by Prof. Martin. 9.0, Wesemann, Talk on Economics : Social Es penditure. Chimes and Weather Report. 9.5, Exchange Quota- 8.0, Celebration of the 70th Birthday of Wossidlo, tions and News. 9.10, Orchestral Concert : March, relayed from the Rostock University. 8.55, Weather Jollity (Ganglberger) ; Selection from Bohemios Report. 7.0, Talk on Women's Fashions by Ida (Vives) ; Waltz, España ( Waldteufel) ; Demande SATURDAY, JANUARY 26th. MThI- Hoffmeister. 7.20, Grieg -Svendsen Concert; et réponse (Coleridge -Taylor) ; Ballet from La Gioconda Overture to Im Herbst (Grieg) ; Scandinavian Folk- Ponchielli) ; Indian March, Taj Mahal (Hansen- song for String Instruments (Svendsen) ; Vocal antj Lotter). 10.0, Programme relayed from Madrid, All Times are reduced to Greenwich Orchestral Selection from Björnson's Amljot Gelline EAJ7. (Grieg) ; .Two Norwegian Rhapsodies (Svendsen) ; Mean Time and are p.m. except Songsngs (Grieg) ; Norwegian Carnival ( Svendsen) ; BERGEN (388 metres) ; 1.5 kW. -5.30, Programme Sarabande (Grie ,) ; Selection from Aus Holbergs for Girls. 6.0, Programme for Children. 7,0, Orches- where otherwiáe stated. Zeit (Grieg) ; Festival Polonaise (Svendsen) ; Peer tral Concert. 7.30, Programme of Concertina Selec- Gynt Suite (Grieg). 8.50, Humorous Programme. tions. 7.50, Topical Talk. 8.0, Mrs. von der Lippe 9,30, Weather Report, News, Sports Notes, Snow Konow, Talk: George Eliot. 8.30, Orchestral Report and Programme Announcements. 10.50, Concert. 9.0, Weather Report, News and Time gàrtelein, (d) Kindes Gebet, (e) Mittag, (f) Folksong; North Sea and Baltic Weather and Ice Report. Signal. 9.15, Dance Music. 11.0 (approx.), Close Duets (Dvorak), (a) Bestimmung, (b) Der Abschied, (c) Das Seidenband (d) Der letzte Wunsch. 8.0, Down. H LVERSUM (1,071 metres) ; 5 kW. -9.40 a.m., Mafalda Salvatini Song Recital from the Concert Tinte Signal and Daily Service. Police Hall. News. Silesian Press Festival 11.40 a.m., BERLIN ( Königswusterhausen) (1,250 metres) ; 40 9.0, 9.30, relayed Announcements. 11.55 a.m., Musical Selections. kW.- 12.45, Phototelegraphy Transmission. 1.30; from the Concert Hall, followed by Dance Music. 1.40, Concert relayed from the Tuschinski Theatre, Programme tor Children. 2.0, Herr B. K. Graef, 11.0 (approx.), Close Down. Amsterdam, under the direction of Mr. Max Tak, with Talk : Elocution. 2.30, Weather Report and Ex- Pierre Palla (Organ). 8.40, Italian Lesson by Mr. change Quotations. 2,40, Talk for Women by Alice BRtXNN (932 metres) ; 2.5 kW. -4.45, German Trans- Giovanni Rizzini. 4.40, French Lesson by Mr. Ray- Fritz mission. 5.15, Topical Talk, by Dr. Jerabek. 8.0, Fliegel -Bodenstedt. 8.0, Educational Talk by mond Lafont. 5.40, Orchestral Concert of Marches : Talk on the following transmission. 6.15, "The Westermann. 8.30, Programme relayed from Ham- The Gladiators' 'Farewell (Blankenburg) ; Soldaten- : Lantern " : Opera (Novak) from the National Theatre, burg. 4.30, Herr Hesslein, Talk Public Opinion blut (Blon), Florentine March (Fucik) ; March of the : Bränn. 9.0, Programme from Prague. 9.25, Tzigane and Officialdom. 5.0, Herr Montel, Talk The Cadets (Sousa) ; El Capitan (Sousa) ; Barataria Music relayed from Bratislava (278 metres). Influence of Co-education on the Youth of Big Cities. (Sullivan) ; Retour à la France (Mezzacapo) ; Le 5.80, Elementary Spanish Lesson. 5.55, Dr. Herse, Régiment de Sambre et Meuse (Turlet) ; Hoch und ; 1.6 kW. Talk : Lessing in Wolfenbüttel. 8.20, Talk. 7.0, BRUSSELS (396.3 metres) -5.0, Concert Deutschmeister (Ertl) ; Old Comrades (Teike). from the Armenonville Tea- Agricultural Programme : March, Entry of the rooms. 8.0, Elementary 8.25, German Lesson by Mr. Edgar Grün. 7.25, Gladiators (Fucik) ; Gavotte, Zircus Renz (Fliege) ; English Lesson. 6.25, Intermediate English Lesson. Police Announcements. 740, Programme arranged Waltz, Kiinstlerleben (Joh. Strauss) ; Talk on The 6.45, Pianoforte Selections. 7.0, Gramophone Selec- by the Workers' Radio Society- Concert and Talk. : Travelling Circus in the Country ; . Overture to Light tions. 7.30, " Radio -Chronique.' 8.0, Concert 11.10 (approx.), Close Down. Cavalry (Suppé) ; March, Der Jongleur (Rosey). Mass in F Minor No. 3 (Bruckner) ; Graner Festmesse '8.0, Programme Irons Voxhaua. (Liszt) ; In the Interval : Topical Talk, followed by News and Talk in Esperanto. 10.15, Concert from the RUI I (338.3 metres) ; 4 kW.- Transmits on 1,852 metres from 5.40 p.m. 12.10.. Concert of Trio Music. BERLIN (Voxhaus) (475 metres) ; 4 kW. -9,15 a.m., Palace Hotel Restaurant. 11.0 (approx.), Close Down. Opening Ceremony in connection with the Berlin 2.40, Programme for Children. 5.10, Gramophone BUDAPEST (555.5 metres) ; 20 kW. -3.0, Talk for Selections. In the Interval at 5.80, Talk by Father Green Week," relayed from the Kaiserdamm Ex- Gru]. Catholic Bulletin. hibition HalL Musical Selections. 9.30 a.m., Scouts. 4.0, Literary Talk. 4.40, Concert of Trio Music 6.30, 8.40, English Lesson, Address of Welcome by Hans Jürgen von with Vocal Selections by Jolán Ling. 5.40, Talk. 7.10, Lesson in Dressmaking. 7.40, Talk by Dr. J. Hake, Director of the Exhibition, followed by 8.15, " Ritter Johann ": Operetta in Three Acts Kranendonk. 8.20, Concert by Street Musicians of Programme of Talks including Talk by Lord (Paukratius Kacsóh). 8.50, Time Signal, News, Amsterdam.: Vocal, Accordion and Street Organ Selections. 9.20, Songs to the Lute. Mayor Böss. 2.80, Mr. P. V. Metzeithiu, Talk : Weather Report and Concert by the Tzigane Orchestra Domestic Conditions in America. 3.0 Prof. W. from the Café Spolarich. Andrae, Talk : The Tower of Babylon. 3.30, Concert KALUNDBORG (1,153 metres) ; 7 kW.- Programme from the Clou Concert Hall, followed by Advertising CRACOW (314.1 metres) ; 1.5 kW. -4.0, Mme. Joter, also for Copenhagen (339.8 metres). -8.30 a.m. Notes. 5.30, Felix Stiemer, Talk : Friendship as Talk : Flemish, French and Italian Stories. 425, Morning Gymnastics. 10.0 a.m., Weather Report. Destiny- Frederick the Second and Voltaire. 8.0, Programme from Warsaw. 4.55, Programme for 10.15 a.m., Educational Talk. 2.0, Programme for Dr. Richard Stein, Talk : Belgian and Dutch Music, Children. 5.50, Miscellaneous Items. 8.10, Review of Children. 2.30, Orchestral Concert. In the Interval : Carl Lassen, with Illustrations. 6.30, Prof. Hans Delbrück, Talk : the Foreign Politics of the Past Week by Mr. Jean Reading by Schionniug. 5.20, Car. C. The Relation of Various Forms of Government to Regula. 8.58, Time Signal from the Astronomical Talk : Mrs. Heiberg and her Circle. 5.50, Weather War and Peace. 7.0, Vocal and Orchestral Concert: Observatory. 7.0, Chimes from the Church of Notre Report. 8.0 News and Exchange Quotations. 8.15, Overture to La Belle Galathée (Suppé) ; Soprano Dame and News. 7.30, Programme from Warsaw Time Signal. 6.30, Prof. H. O. Larsen. Talk : Former Solos, (a) Song from Die Teresina (Straus), (b) Song 9.30, Concert from a Restaurant. 10.30 (approx.), Agricultural Crises. 7.0, Chimes from the Town Hall. from The Czarevitch (Lehár), Selection from Zigeuner- Close Down. 7.2, Concert of Old -time Music t Quintet Selections, primas (Kalman) ; Soprano Solos, (a) Song from Der (a) Minuet in E Major (Mozart), (b) Selection from No, Orlov (Granichstaedten), (b) Song from Der blonde DUBLIN, Call 2RN (411 metres) 1.5 k\V. -1.30, (c) Selection from En S..ndag pas Ansager, (d) Jomfru Zigeuner (Knopf) ; Red Roses (Königsberger) ; Weather Report and Concert of Gramophone Selec- vil de used i Skoven (Krageland), (e) Lette Bölge, naar Indian Temple Dance (Königsberger) ; March, Bis tions. 7.20, News. 7.30, Recital of Poems by May du blearier (Tholle) ; Four Recitations ; Five Quintet früh um fünf (Lincke). 8.0, Dialogues from World Pitchford. 7.45, Irish Lesson by Seamus O'Duirinne. Selections, (a) Tyrolese Waltz and Hopsa, (b) Cradle - Literature ; Selections from Three Funeral Orations 8.0, Symphony Concert by the Station Symphony Song (Hartmann), (e) Waltz, Queen Louise (Lunt (Bernard von Fontenelle) ; An Address for Free Orchestra and Miss Culwick's Choir. 10.30, News, bye), (d) Do you remember the Autumn 1 (Heise), masons (Lessing). Selections from Faust (Lessing), Weather Report and Close Down. (e) Fantasia on Danish Folk Songs and Dances (Larsen), followed by Weather Report, News, Sports Notes and followed by News. 8.30, Emil Bonnelycke, Talk : Dan- Dance Music. 11.30 (approx.), Close Down. FRANKFURT (421 metres) ; 4 kW.-3.35, Orchestral ish Poets. 9.0, Concert of Light Music: Marche Concert of Operetta Music : Wedding March from lorraine (Ganne) ; Overture to Les Saltimbanques BERN (407 metres) ; 1.5 kW.-3.0, Concert by the Didi (Oscar Straus) ; Waltz from The Czardas Princess (Ganse) ; Polka, Les vendredis (Borodine, Sokoloff Kursaal Orchestra. 3.30, Programme for Children (Kalman) ; Song ; Potpourri from Das Puppen- and Liadoff) ; Selection from " L'Africaine " : Opera 4.0, The Kursaal Orchestra. 8.29, Time Signal and mädel (Fall) ; Waltz Irons Rastelbinder (Lehár) ; (Meyerbeer) ; Entr'acte- Gavotte for String Instru- Weather Report. 8.30, Dr. Hans Müller, Talk : Potpourri from The Star -gazer (Lehár) ; Song ; Two ments (Gillet) ; Waltz, Blue Lagoon (Strauss) ; Selec- The Peasant National Week in Schloss Honigen. Selections from Polenblut (Nedbal) ; In the Interval : tion from 1 he Czardas 'Princess (Kalman) ; The Top 7.0, Popular Programme. 8.45, News and Weather News and Announcements. 510, Reading from Doktor (Gillet) ; March, Fairest of the fair (Sousa). 10.0, Report. 9.0, The Kursaal Orchestra. 9.85, Dance Katzenbergers Badereise (Jean Paul), by O. W. Dance Music from the Industri Restaurant. U.0, Music. 11.0 (approx.), Close Down. Studtmann. 5.30, The Letter Box. 5.45, Esperanto Chimes from the Town Hall. 11.15 (approx.), Close Lesson by Herr W. Wischhoff. 8.15, Armin Gessner, Down. BRESLAU (32L2 metres) ; 4 kW. -8.20, Shorthand Talk : The Insurance of Employees. 8.45, Clemens Lesson. 6.50, Topical Debate between Four Young Taesler, Talk : Lessing as a Pioneer of German Ideal- KATTOWFPZ (418 metres) ; 10 kW. -3.0, Concert of Men. 7.15, Recital of Songs and Duets : Songs ism. 7.15, Variety Programme. 8.0, Programme Gramophone Selections. 4.0, Music Lesson by Prof. (Göhler), (a) Ich komme bald, ihr goldnen Kinder, relayed from Voxhaus. U.30 (approx.), Close Down. F. Sachse. 4.25, Children's Letter Box. 4,55 Pro- (b) Serenade, (c) Das Scheiden, (d) Der schönste gramme for Children. 810, Talk by Prof. K. Sintm. K. Platz, (e) Im \Valde ; Duet, So let us wander (Brahms) ; HAMBURG, Call HA (in Morse) (392 metres) ; 4 kW.- 7.0, Talk by Mr. Rutkowski. 7.30, Programme Soprano Son ,s (Reger), (a) Klein Marie, (b) Der 9.15 a.m., News. 10.0 a.m., Programme of Gramo- relayed from Warsaw. 9.0, Weather Report and News Kenig aus 61111 Mervenland, (e) In einem Rosen- phone Records. 11.10 a.m., Weather Report. 1115 8.30, Dance Music. A 34

www.americanradiohistory.com JANUARY 23rd, r929. W l ®00 ICI W©tll Programmes from Abroad. - ROME, Call 1RO (443.8 metres) 3 k\V. -8.50, 'port. KAUNAS (2,000 metres) ; 7 kW. -3.0, Gramophone Saturday, January 26th. Notes, News, Exchange Quotations and Weathes Selections. 3.15, Recent Literary Publications. Report. 7.29, Time Signal and Report of the Inter- 3.45, Radio Patarejas. 4.30, Announcements. 5.0, national Iabour Office at Geneva, 7.45, Vocal ani Weather Report and News. 5.30, Agricultural Re- Instrumental Concert : Overture to Der Freischütz port. 6.0, Aviation Notes. 6.30, Evening Entertain- All Times are reduced to Greenwich (Weber) ; Concerto in A Minor for Violin and String Orchestra : ment. Mean (Vivaldi -Nachez) News and Fashion Talk ; Time and are p.m. except Selections from Aida (Verdi) ; " La Reginetta " LAHTI (1,504 metres) ; 35 kW, -8.20, Variety Pro- Comedy in One Act (Chfarelli) ; Dance Music ; Review where otherwise of gramme. 7.0, Orchestral Selection from The Circus stated. Art and Literature by Lucio d'Ambra ; Dance Princess (Kalman). 7.20, Humorous Song Recital Music. 9.50, Topical Talk and News. 10.0 (approx.), 7.30, Orchestral Selection of Finnish Songs (Jäger). Close Down. 7.45. News in Finnish and Swedish and Close Down. 4.30, Talk by Hans Priebäusser. 5.0, Concert: Selections from Oratorios, (a) Arioso from Israel in SCHENECPADY, Call 2XAF (31.48 metres) , 30 kW.- LANGENBERG (462.2 metres) ; 20 kW,- Programme Egypt (Handel), (b) Confutatis maledictis from Re. 1L30 p.m... White House Coffee Programme from also for Aix-la- Chapelle (455.9 metres), Cologne (263.2 quiem (Verdi), (c) Sonett from Neue Leben (Wolf- New metres), York. 12.0 Midnight, Phil Spitalny's Music and Münster (265.5 metres). -12.5, Concert: Ferrari) ; Five Songs (R. Strauss), (a) Breit' über from New York. 12.30 a.m. (Sunday), Musical Mafalda Marsch (Meyer) ; Waltz, Was tut man mein Haupt, (b) Mein Herz ist stumm, (c) Liebes- Programme from nicht Rochester. LO a.m., National alles aus Liebe (Ascher) ; Overture to Das hymnus, (d) Zueignung, (e) Winterliebe. 5.35, Symphony Orchestra under the direction of Walter Modell (Suppé) ; In Adams Paradies (Urbach); Labour Market Report. 8.0, The Letter Box. 6.30, Damrosch. 2.0 to 4.0 a m., New York Programme. Selection from Orpheus (Gluck) ; Weltenland Suite Humorous Talk by Dr. Robert Weil. 7.10, Musical 2.0 a.m.. Lew White Organ Recital. 2.30 a.m., Concert (Kndmann) ; Tango, Ninon ; (Ascher) Boston, Ich Parodies by Theo Rupprecht. 815, Carnival Pro - by Mildred Hunt and Marimba Orchestra. 3.0 a.m. kann dich nicht vergessen (Ascher) ; Selection from Programme. 9.20, News and Announcements, 9.45. Lucky Strike Programme. 4.0 a.m., Dance Music Madame Pompadour (Fall). 130, Household Hints. Dance Music from the Park Hotel, Munich. 11.0 from the Hotel Ten Eyck, Albany. 5.0 a.m. (approx.), 2.0, Porgramme for Children by Els Vordemberge. (approx.), Close Down. Close Down. 2.40, Arthur \Vurbs, Talk : The Bases of Wireless Technique. Psychological 3.0, Talk for Young NAPLES, Call 1NA (833 metres) ; 1.5 kW. 740, STAMBOUL (1,200 metres) ; 5 kW,- 3.30, Concert. People, by Pater Esch. 3.20, Programme for Children Wireless Talk, Announcements, News and Harbour 4,80, Exchange Rates and Weissleder. Grain Quotations. 5.15, by Maria 3.40, Dr. Maria Zschokke, Talk Notes. 8.0, Time Signal. 8.2, Comedy and Orchestral Concert of Turkish Music. 7.30, Weather Report for Women : Infant's Ailments. 4.0, Line Waller- Selections : Overture, La serva padrona ( Suppé) ; and Time Signal. 7.40, Orchestral Concert : Sahara stein, Talk: German Artists on their Travels. 4.20, " Il Titano " : Comedy in Three Acts (Daori Nicco- Suite (Ackermann) La Belle Berceuse et Musette English Lesson by Prof. F. Hase. of 4.45, Recital demi) In the First Interval : Orchestral Selections, (Alerter) ; Hungarian Dance (Artok-Liszt). 9.0, Songs by Fred Drissen. 5.30, Dr. Salmony, Talk (a) Prelude, Alla regata ( Manente), (b) Grotesque - News and Close Down. Chinese Painting. 5.50, Morse Instruction. 6.15, Intermezzo, Clown (Culotta), (e) Serenade, Amor the Talk for Workers by Dr. Kurt Loose. 6.35, Prof. sogna (Manente). In the Second Interval : Orchestral STUTTGART (374 metres) ; 4 kW. -2,0, Concert Hessen, Talk : What do we know of the Soul t 7.0, Selections (Siede) : (a) The of Star the East, (b) In from the Works of Schubert. 3.0, Orchestral Music Variety Programme, followed by News, Sports Notes, Seville. 9.0, Review of the Week. 9.50, News. 9.55, Commercial Announcements from the Pavillon Excelsior. 5.0, Time Signal and and Concert from the Calendar and Programme Announcements. 10.0, Weather Café Corso, Dortmund. 11.0, Dance Music from the Close Down. Report. 5.15, Herr L. Leibfried, Talk: Fledermaus," Dortmund. 12,0 Midnight (approx.), The Liabilities of Animal Owners. 5.46, Herr Close Down. Baumeister, Talk : Within and Without the Prison OSLO (497 metres) ; 1.5 kW.-Programme relayed by Walls, relayed from Fredriksstad (887 metres), Hamar Freiburg (577 metres). 6.15, (554 metres), Time Signal and Sports Notes. 6.30, Willy Buschhoff LEIPZIG (362 metres) ; 4 kW.-3.0, Paul Prina, Notodden (297 metres), Poragrund (456 metres) and Programme : Quartet I (Borodine) ; Notes Talk : Lessing. 3.30, Orchestral Concert from the Rjukan (242 metres). -5.0, Programme for Children. from my Day-Book ; Selection from Master and Works of Victor Holländer, conducted by the Com= 8.15, Weather Report and News. 6.30, Oscar Wisting, Man (l'olstoy) ; Quartet 2 (Borodine) ; Drinking Song poser. 4.45, Wireless News and Talk. 5.20, Weather Talk : The Discovery of the South Pole. 7.0, Time (from Earth's Lainent (Li Tai Pe) ; Veltinertraube Report and Time Signal. 5.30, Programme relayed SignaL 7.2, Orchestral Concert : Overture to Don (Meyer) ; Abendgefühl (Hebbel) ; Nachtgefühl from Königswuaterhausen. 6.0, Prof. Georg Wit- Juan (Mozart) ; Concerto for Pianoforte and Orchestra (Hebbel); Der Heideknabe (Hebbel) ; kowski, Talk : Lessing as Art Critic. 6.80, Dr. (Schumann); Nocturne, Musette Tambourin and Elegy from chinois (Fritz Kreisler). 7.30, Orchestral Concert Raphahn, Talk : The Sentiment of Europeanism- King Christian Suite (Sibelius) ; Fantasia on Popular of Old Music : Concerto grosso No. 8 in G Minor The Middle Ages. 7.0, Concert by Wanda Schnitzing Norwegian Melodies (Birknes) ; Waltz, Morgenblatter (Corelli) ; Two Songs to the Lute, (a) Rhenish Ballad, (Soprano), Willy Strehl (Tenor), Jorgo Chartofilar Job. Strauss) ; Sélection from The Dollar Princess (b) Death ; andoline), Gunther Sanderson (Elocutionist) and Fall). in Flanders Field Music No. 3 (Krieger) ; 8.30, Weather Report and News. 8.45, Funeral Symphony (on the Death of his Wife) aril Klinger (Piano). 9.0, Labour Market Report, t.opical Talk. 9.0, Recitations by the (Loca- Actor Eugen telli) ; Two Songs to News, Sunday Programme Announcements and Sports Schönberg. Dance Music from the Lute, a) Selection from the 9.30, the Hotel Bristol Song Book of Anna von Köln, (b) Notes. 9.30, Dance Music relayed from Voxhaus. 11.0 (approx.), Close Down. Jesus and the Nuns ; Two Dances (Hassler) ; Three Songs to the Lute ; Suite in A Minor (Telemann), followed by Cabaret MADRID (Union Radio). Call EAJ7 (427 metres) ; PARIS (Eiffel Tower), Call FL (1,488 metres) ; 5 3 kW. Chimes End Exchange Quotations, Programme from Ludwigsburg, and Dance Music 7.0 kW.-5.O, Pasdeloup Concert 7.10, Weather Report. from Voxhaus. followed by Dance Music. 8.0, Dr. Zito, Talk: 7.20, Le Journal Parlé. 8.50 (approx.), Close Down. Inventors and Inventions. 8.25, News. 9.45, Agri- cultural Report Market Prices and News. 10.0, PARIS (Petit Parisien) (336 metres) ; 0.5 kW.- TOULOUSE (Radiophonie du Midi) (383 metres) ; Chimes and Exchange Quotations, followed by Selec- 8.45, Gramophone Selections, Talk and News. 9.0, 8 kW.-12.45, Concert. 8.0, Exchange Quotations tion from " Campanone "- Musical Play (Mazza and Concert : Overture to Voyage en Perse (Filippncci); and News. 8.30, Concert from the Works of Strauss. di Franco). In the Interval at 12.0 Midnight (approx.), Selection from Nelly (Lattés). 9.25, News and An- Der Kuss Waltz : Roses of the South ; Waltz Wiener- News. blut ; 12.30 a.m. (approx.), (Sunday), Close Down. nouncements. 9.30, Symphony Concert : First Suite Waltz, Wine, Women and Song. 8.45, Selec- of L'Arlésienne (Bizet); Symphonic Dances (Grieg). tion of Argentine Tangos : Queja Indiana ; Anoche MILAN, Call 1MI (504 metres) 7 kW. -3.32, Concert 10.0, News and Concert : Ballet from Les Hérétiques a Las Dos ; Caido del Cielo ; Bandoneon. 9.0, Concert of Quintet Selections : Symphony, La moglie rapita (Levadé) ; La splendeur vide (Saint-Saens) ; Slavonic arranged by " La Dépéche." In the Interval, Argen- (Driap) ; Moresca (Frontini) ; La fidanzata di Mm March (Tchaikovsky). tine Songs with Guitar Accompaniment, (a) Mar (Cusemà) ; Romanza senza parole (Azioni) ; Fiore bravio, (b) Che papusa, (c) Ramona, (d) El Carretero, Madrileno (Ferri). 4.0, Exchange Quotations. 4.20, PARIS (Radio - Paris), Call CFR (1,789 metres) ; 13 (e) Dandy, (f) Adios Muchachos. 10.0, North African Programme for Children. 4.45, Agricultural Report kW.-12.80, Concert of Columbia Gramophone News. 10.15 (approx.), Close Down. and News. 7.80, Time Signal. 7.32, Wireless Talk Records : Tango, Alma Criolla, by Lucchesi's South and Announcements. G. M. 7.45, Ciampelli, Illus- American Orchestra ; Miss Annabelle Lee, by The VIENNA (520 metres) ; 15 kW.-3.50, Play for trated Talk : Verdi. 8.0, Relay of an Opera from the Knickerbockers ; The Blue Room, by Fred Rich and Children, adapted from Grimm's Fairy Tales. Scala Theatre. In the Intervals: 4.30, Reading from his Orchestra ; The Varsity Drag, by Guy Lombardo Pianoforte Beethoven : L'Innocente Recital of Sonatas Moonlight (D'Annunzio) News and Economic and his Royal Canadians ; Laugh, Clown, Laugh, by Sonata in C Sharp Minor ; Notes. Op. 27 Sonata Op. 90 in Ted Lewis and his Orchestra ; A Hundred Years from E Minor. 5.20, Introductory Talk and Reading now, by The Tris Sisters; Popular Songs of White from the Werks of Alfred Rottauscher (died January MOTALA (1,365 metres) ; 40 kW.- Programme also Russia, by the Don Cossack Chorus ; Third Romance, 9th, 1926). 8.10, Talk with Musical Illustrations - for Stockholm (438 metres), Boden (1,200 metres), The Hunt (Mendelssohn), by Francis Plante (Piano); Eichendorff as a Song -composer: Wanderlied Goteborg metres), (346.8 Malmo (229 metres), Oster- The Unfinished Symphony (Schubert), by the New (Mendelssohn) ; In der Fremde (Schumann) Inter- Bond (720 metres), Sundsvall (545.5 metres). -4,0, Queen's Hall Orchestra under the direction of Sir mezzo (Schumann) ; Die Stille (Schumann) ; Romance Concert of Music. Programme Light 5.0, for Children Henry Wood ; Ballet from Marouf (Rabaud), by (Dr. Franz) ; Anklänge (Brahms) ; Die Nacht (Hugo relayed from Halmstad (215.8 metres). 5.30, Sailor's Symphony Orchestra under the direction of M. Rabaud: Wolf) Nactttzauber (Hugo Wolf). 7.0, Time Signal Songs and Waltzes relayed from Goteborg. 6.15, In the Interval, News. 2.0, Market Prices and Religious and Weather Report. 7.5, " Der Hochstapler "- Nils Hasselskog, Talk: From Grönköping, relayed Information. 3.30, Exchange Quotations. 3.45, Comedy in Three Acts (Goldoni) translated by Lola from Violin : Goteborg. 6.45, Recital Rondino on Concert arranged by " Les Rosati." Market : ; 4.50, Lorme, followed by Orchestral Concert Overture a Theme from Beethoven ( Kreisler) Tambourin Prices and News. 6.30, Agricultural Report and to Raymond (Thomas) ; Waltz, Acceleration (Joh. (Leclair) ; Nocturne in C Minor (Chopin -Auer) ; Exchange Quotations. 6.45, Gramophone Selections. Strauss) ; Memories of Grieg (Urbach) ; Violin Solo, Appassionato (Vidor). 7.0, Military Band Concert 7.30, Pianoforte Lesson by M. Pierre Lucas. 8.0, Dr. Fantasia on Faust (Gounod) ; Potpourri, The Little relayed from Umea (229 metres) ; Victory March Roubinovitch, Talk : The Mental Condition of the Dutch Girl (Kálmán) ç Potpourri, Wiener Spazier- (Blon) ; Overture to Benvenuto ; Cellini (Berlioz) Naughty Child, followed by Market Prices and News. gänge (Komzák) ; Gallop, St. Petersburg Sleigh Ride Waltz, Ich liebe dich (Waldteufel) ; Selection from 8.15, Concert arranged by " Le Matin " : Symphonic (Eilenberg), followed by Phototelegraphy Trans- L'Africaine (Meyerbeer) ; Erotica (Grieg) ; American Selections ; Selection from Le Médecin malgré lui mission. Suite ; (Turban) March (Blankenburg). 8.0, Topical (Gounod) ; In the Intervals : News and Announce- Talk, News and Weather Report. 8.45, Programme ments. WARSAW (1,415 metres) 10 kW. -4.55, Programme of Old Time Dance Music, relayed from Falun (333 for Children. 5.50, Miscellaneous Items. 6.10, " Radio - mmee ). 9.30, Dance Music. 11.0 ( approx,), Close PRAGUE (343 metres) ; 5 kW. -4.40, Mr. Koudelka, Chronique," by Dr. M. Stepowski. 6.35, News and Talk : Mr. Lloyd George. 4.50, Agricultural Talk. Time Signal. 7.80, " Adieu Mimi "-Operetta in Three 5.0, German Transmission, News and Lessing ; Recital. Acts (Benatzky). In the Interval, Theatre Notes. 9.0, MUNICH (538.7 metres) 4 kW.- Programme relayed 6.0, Programme relayed from Hrünn. 9.0, Time Signal Weather Report and News. 9.20, Police Announce- by Augsburg (566 metres), Kaiserslautern (273 metres), and News. 9.25, Tzigane Music relayed from Bratis- ments and Sports Notes. 9.30, Dance Music from and Nuremberg (240 metres). -3.0, Quartet Concert. lava (278 metres). the Oaza Restaurant. 10.30 (approx.), Close Down. A 35

www.americanradiohistory.com ?.. -19i 4

roe Wteago JANUARY 23rd, 1929. WoAd Programmes from Abroad. Le coin des enfants -Suite (Debussy), (a) Doctor Gradus - SUNDAY, JANUARY ad Parnassum, (b) Sérénade à la poupée, (c) Le petit ALGIERS, Call PTT (353 metres) ; 1 kW.-12.30, 27th. berger, (d) Berceuse d'éléphante, (e) La neige danse. Concert of Instrumental Music by the Station Or- (f) Golliwog's Cake -Walk. 10.0, Programme of Dance chestra, conducted by C. Cerlini. Jota Navara, Music by the Palace Hotel Orchestra : Conductor. Violin Solo (Sarasate) rendered by M. A. Gonzales. All Times are reduced to Greenwich Teddy Petersen ; in the Interval at 11.0, Relay of Chimes from the Town Hall. 11,30 (approx.), Close BARCELONA (Radio Barcelona), Call EAJ1 (350.5 Mean Time and are p.m. except Down. metres) ; 1.5 kW. -11.0 a.m., Relay of Cathedral Chimes. 11.5 a.m., Weather Conditions and Forecast where otherwise stated. KATTOWITZ (416 metres) ; 10 kW.-11.20 a.m. for Europe' and Spain, followed by Report on Aviation (approx.), Musical Selections the Station Quartet. Route Conditions. 1.30, Musical Programme by the 1..0, Talk. 120 and 1.40, Two Talks on Agricultural Iberia Trio. In the Interval, Gramophone Selections. Subjects. 2.0, Weather Conditions and Forecast. 2.45 to 5.30, No Transmission. 5.30, Opening Signal Instruction by Alfred Dormans. 8.0 a.m., Evan- 2.15, Symphony Concert, by the Warsaw Philharmonic followed by R. lay of Part of an Opera from the Gran gelical Musical Festival with Vocal and Instrumental Orchestra. 4.30 to 5.20, No Transmission. 5.20, and Sermon. Recital of Organ l'estro del Liceo. In the Interval, Stock Exchange Items 11.0 a.m., Popular Concert from Warsaw : Le Nil (X. Leroux), Notes and Market Prices. 8.0 to 8.20 Weekly Report Music by Professor Hans Sachem relayed from the rendered by Mme. Mankiewicz (Soprano), accompanied from the Catalonian Institute of Agriculture at San Messehalle, Cologne, Magnificat (Delphin Srungk 1601- by M. T. Gociawski (Violoncellist) and Prof. L. Urstein Isidro. 8.20, Programme by the Station Orchestra: 1684). 12.0 Noon, Orchestral Concert. 1.80, Talk. 6(Pianist). 6.0, Various Announcements. 6.20, Talk. Scènes foraines (Ed. Mignan), (a) Tohu -Bohu, (b) 5.0, Talk. 7.15, Relay of an Opera or Play followed by .56, Time Signal. 7.0, Talk. 7.30, Relay of Evening Au Palais d'Orient, (c) La Danse d'Alsace, (d) Carrousel. Late News and Announcements, Sports Results and Concert from Warsaw. 9.0, Weather Conditions and 8.40 Sports Results 9.0 (approx.), Close Down. Concert of Light Music and Dance Selections. 11.0 Forecast, Press News Bulletin and Sports Notes. (approx.), Close Down. 9.30, Dance Music Programme. 10.30 (approx.), 1.5 kW. Divine Close Down. BERGEN (368 metres) -8.30 a.m., Call 6CK (222 ; 1.5 kW. -8.30, Con- Service Relay. 1130 a.m., Weather Report and CORK, metres) cert of Vocal and Instrumental Music : Song Selec- Forecast, followed by News and Announcements. KAUNAS (2,000 metres) ; 7 kW. -2.30, Programme tions by Miss Raymonde Amy (Soprano). 11.0 of Fairy Stories, Songs and Music for Children. 3.0, 7.0, Concert of Orchestral Music. 8.0, " Syndens National Anthem and Weather Report and Forecast. Sold " -Play in one Act by Hjalmar Meidell, Dramatis Young People's Programme. 3.30, Talk on Health Personm: Harriet -Doris Johannessen, and Her 11.15 (approx.), Close Down. and Medicine by Doctor Jurgelionis. 4.0, Talk by J. Mother -Jenny Jebsen. 9.0, Weather Report and Ardickas on Industry and Daily Life. 5.0, Programme CRACOW (314.1 metres) ; 1.5 kW. -9.15 a.m. to 10.45 for Vilna. Talks in the Lithuanian and Ruthenian Forecast, Late News Bulletin and Time Signal. 9.15, Relay of Divine Service from a Cathedral. Programme of Dance Music. 1L0 (approx.), Close a.m., Languages. b.0, Weather Conditions and Forecast 10.56 a.m., Relay of Fanfare from the Church of Notre and News Bulletin from the Press. Down. Dame, followed by Time Signal and Weather Con- ditions and Forecast. 11.15 a.m., Concert of Orchestral BERLIN (Königswusterhausen) (1,250 metres) ; 40 Music from the Philharmonic Hall, Warsaw. LO KÖNIGSBERG (280 metres) ; 4 kW.- Programme kW. -7 55 a.m., Chimes Relay from Potsdam Garrison and 1.20, Talks for Farmers. 1.40, Agricultural Report relayed by Danzig (165 metres). 8.0 a.m. (Königs- Church. 8.0 a.m., Relay of a Recital of Religious by Dr. St. Wasniewski. 2.0, Meteorologiml Report. berg only), Recital of Vocal and Instrumental Sacred Music and Address from Voxhaus, followed by Chimes 2.15, Afternoon Concert by the Warsaw Philharmonic Music with Sermon. 10.0 a.m. (Königsberg only), from Berlin Cathedral. 10.30 a.m.; Programme of Orchestra. 4.55, Talk by M. J. Pietrzycki: " Through Weather Report and Forecast. 10.5 a.m.. Musical Orchestral Music relayed from Voxhaus. 12.45, Switzerland -on the Trail of Polish Memories." 0.0, Programme. 11.55 a.m., The International Time Experimental Picture Transmission. 1.30 to 2.25, Various Announcements. 6.20, Talk. 6.56, Time Signal from Nauen, followed by Weather Report and Three Agricultural Talks, relayed from Voxhaus. Signal from the Astronomical Observatory. 72 Forecast. 1.0, Palle on Chess by P. S. Leonhardt. 3.0, Talk. 3.30, Musical Programme. 5.0, Talk. Relay of Fanfare from the Church of Notre Dante, 2.0, Elementary Spanish Lesson by Kurt Metze. 6.0, Talk. 7.0, Concert, Play or Opera followed by followed by Sports Bulletin. 9.0, Relay from Warsaw. 8.5, Programme from Danzig. " Im weissen Ressl " Late News and Announcements and Dance Music 9.30, Concert Programme from the Pavillon Restaurant. Comedy in Three Acts by Oscar Blumenthal and Programme. 11.30 (approx.), Close Down. 10.30 (approx.), Close Down. Gustav Kadelburg, produced by Otto Norman, followed by News of the Day and Sports Results and Musical Programme. 11.30 (approx.), Close BERLIN (Voxhaus) (475 metres) ; 4 kW. -7.55 a.m., DUBLIN, Call 2RN (411 metres) ; 1.5 kW.-8.30, Relay of Chimes from Potsdam Garrison Church. Concert Programme, relayed from Cork : Selections Down. 8.0 a.m., Recital of Sacred Music, Vocal and Instru- by the No. 2 Amy Band. 11.0, National Anthem and mental Selections with Sermon, followed by the Chimes Weather Conditions and Forecast. 11.15 (approx.), LAHTI (1,504 metres) ; 35 kW.- Programme also from Berlin Cathedral. 10.30 a.m., Morning Concert. Close Down. for Heleingfors (374 metres). -7.0 a.m., Sacred Service by Hans W. Priwin. Relay in the Finnish Language. 9.50 a.m., Press LO, Morse Lesson for Beginners Concert 1.30 to 2.25, Programme of Agricultural Talks for GENEVA (760 metres) ; 1.5 kW.-9.0 a.m., Relay of News and Anncuucements. 10.5 a.m., Farmers. 1.30, Notes and Practical Hints for the Sacred Service with Address from the Victoria Hall. Programme. 10.59 a.m., Weather Conditions and Agriculturist. 1.45, A Weekly Retrospect of the 8.0, Recital of Organ Music from the Temple de Forecast and Time Signal. 11.0 a.m., Relay of Market Prices and Weather Report and Forecast. Carouge, by M. Roger Vuataz (Organist), with the Church Service in the Swedish Language. 4.57, 1.55 Talk on an Agricultural Subject. 2.30, Reading collaboration of Mlle. Edmée Defago (Vocalist). Time Signal and Weather Conditions and Forecast. of Fairy Stories for Children. Talk. 3.30, 8.25, Concert of Classical Music by the Station Or- 3.0, by Erkki Linko. Invitation to Concert Programme. 7.0 (approx.), Opera, Play or HAMBURG, Call KA (in Morse) (392 metres) ; 4 kW.- chestra, conducted Concert, followed by Weather Conditions and Forecast, Programme relayed by Bremen (273 metres). Hanover the Dance (C. M. Weber). 7.45, Late News and An- Late News and Announcements and Sports Notes. (566 metres) and Kiel (250 metres). -7.20 a.m., Time nouncements in the Finnish and Swedish Languages. 9.30, Programme of Dance Music. 11.30 (approx.), Signal. 7.25 a.m., Weather Conditions and Forecast, 8.30 (approx.), Close Down. Close Down. followed by News and Announcements. 7.40 a.m., Talk on Problems of Industry. 8.0 a.m., Weekly Legal LANGENBERG (482 2 mettes) ; 20 kW.- Programme The International Time Signal also for Aix- la-Chapelle (455.9 metres), Cologne (263.2 BERN (407 metres) ; 1.5 kW. -9.30 a.m. to 10.30 Notes. 11.55 a.m., from Hauen. 12.5 (for Hamburg and Kiel), Morning metres) and Minster (265.5 metres). -8.45 a.m., a.m., Catholic Sermon. 12.0 Noon, Time Signal Lesson in Self-Protection by Dr. Ludwig Bach. 7.5 and Weather Report and Forecast. 12.5, Afternoon Concert Programme. 12.5 (for Bremen), Morning Concert by the Wireless Orchestra. 12.5 (for Hanover'), a.m., German Shorthand Lesson by Hans Molitor. Concert. 6.29, rime Signal and Weather Report 7.25 a.m., Survey in Esperanto of the Programmes of and Forecast. 7.0, "Don _luau," -Opera in Three Acts Concert of Gramophone Records. 1.0, Entertainment for Children. 3.0, Talk. 10.50 (for Hamburg, Bremen the Week by Alfred Dorrnanns. 7 30 a.m. to 7.55 (W. A. Mozart) relayed from Basle (on 1010 metres). a.m., Esperanto Lesson by Alfred Dormans. 8.5 9.0 (approx.), In the interval Sports Notes, General and Kiel), North Sea and Baltic Weather Conditions and Forecast. 11.0 (approx.), Close Down. am., Evangelical Morning Festival of Sacred Music News Bulletin and Weather Report and Forecast. 0.0, with Sermon in the interval. 12.0 Noon, Afternoon Evening Concert. 9.40, (approx.), Close Down. Music. HILVERSUM (1,071 metres) ; 5 kW. -12.10, Musical Concert of Orchestral 1.30, Talk. 6.0, Talk. Selections by the Station Trio. 2.10, Lecture with 7:15, " The Dollar Princess "-Operetta (Leo Fall), B>IZIERS (211 metres) ; 0.6 kW.-6.0 to 7.0, L'heure by Kith and produced by Zimmermann Musical Illustrations : " The Pianoforte Sonatas of conducted de la Radio- Agricole française- Concert Programme. followed by Late News Bulletin, Concert of Light Beethoven," Lecturer, Mr. L. Schmidt ; Pianist, Mr. 8.45, Concert of Light Music on the Pathé and Pathé - Egbert Veen. 7.40, Time Signal. 7.42, General News Music and Dance Music conducted by Eysoldt. 110 Art Gramophone Records, arranged by the Maison Musical Pro- (approx.), Close Down. Close Bulletin and Communications. 7.55, Relin- Minoles at Béziers. 10.30 (approx.), gramme. 10.40 (approx.), Close Down. Down. LEIPZIG (362 metres) ; 4 kW.-Programme relayed by (276 metres). -7.30 Programme of ; 4 Transmits from 6.40 Dresden a.m., BUIZEN (336.3 metres) kW.- Morning Concert Programme. BRUSSELS (398.3 metres) ; 1.5 kW. -5.0, Concert on 1,852 metres. -8.5 a.m., Relay of Divine Service. Organ Music 8.0 a.m.. Programme by the Orchestra of the Armenonville 12.10, Musical Programme by the Station Trio. 1.10, 10.0 a.m. Talk. 10.30 a.m., Talk. 11.0 a.m., Tea Room, Brussels. 8.0, Programme for Children Talk. 1.40, Talk. 2.10, Musical Selections Programme. Musical Programme. 12.0 Noon, Time Signal. 12.2, organised by the Children's Theatre under the direction 4.55, Relay of Divine Service and Sermon from a Talk. 12.30, Talk. LO, News from the Foreign of M. Libn Leroy. 6.30, Concert Programme. 7.30. Church in Amsterdam 7 Address on the 38th and 39th Press, followed by Review of Events Abroad. 2.0, Radio- Chronique. 8.0 (approxl, Musical Programme Verses of the 5th Chapter of the Gospel according to Latest Gramophone Records from the " Merkur " followed by General News Bulletin from the Evening St. Matthew, by Dr. W. E. van Duin. 10.25, Epilogue, Musical Publishers, followed by Advertising Notes. Press. 11.0 (approx.), Close Down. rendered by a Choir under the Direction of Mr. Jos. H. 5.0, Talk : " For and Against Capital Punishment," Pickkers. 10.40 (approx.), Close Down. by Dr. Otto Landsberg Minister for Justice relayed from Berl n. 5.30, Talk. 6.0, Talk. 6.30, Relay BUDAPEST (555.5 metres) ; 20 kW. -8.0 a.m., General of an Opera. 9.0, General News Bulletin and Sports ; 7 Programme News Bulletin and Programme for Women. 9.0 a.m., KALUNDBORG (1,153 metres) kW.- Dance Music Programme, relayed from for (339.8 metres). a.m., Relay of Results and Relay of Church Service with Sermon. 8.15, Pro- also Copenhagen -9.0 Berlin. 11.30 (approx.), Close Down. gramme o the Wireless Lyceum including Talks and Morning Service and Address from a Church in Copen- Musical Selections. hagen. 10.30 a.m. to 10.40 a.m. (Kalundborg only), Weather Conditions and Forecast from the Copenhagen LYONS (Radio Lyon) (291 metres) ; 1.5 kW. -7.30, of News " COLOGNE (263.2 metres) ; 4 kW.- Programme also Meteorological Institute. LO, Divine Service and The Radio Lyon " Journal Parlé " and for Aix -la- Chapelle (455.9 metres), Langenberg (452.2 Sermon, 2.30, Concert by the Station Orchestra. Announcements, Press Review, Survey of Theatre metres) and Minister (265.5 metres). -8,45 a.m , Self - 5.50 (Kalandborg only), Weather Conditions and Fore- Programmes and Announcements. 8.0, Programme of Light Music rendered by Madame Ducharne Si'..' _ Defence Lesson by Dr. Ludwig Bach. 7.5 a.m., cast from the Copenhagen Meteorological Institute. t. German Shorthand Lesson by Hans Molitor. 725 6.0, Press News Bulletin. 615, Time Signal. 6.30 (Pianist), M. Camand (Violinist) and M. Testanière a.m., Esperanto Review by Alfred Dommanns of Talk. 7.0, Chimes Relay from Copenhagen Town Hall. ('Cellist) : Selections from " La Dame blanche "- - Concert of Popular Music by the Station Orchestra: Opera (Boieldieu). 10.0 (approx.), Close Down. forthcoming Programmes. 7.30 am., Esperanto 9.0, A 36

www.americanradiohistory.com JANUARY 23rd, 1929. WflMSZSZO 103 Woiilc1 Programmes from Abroad. - STUTTGART (374 metres) 4 kW.- Programme relayed by MADRID' (Union Radio), Call EAJ7 (427 metres) ; Sunday, January 27th. Freiburg (577 metres). -1.0, Programme 1.5 kW.- Programme relayed by Salamanca (EAJ 22) for Children. 2.0, Talk or Reading. 2.30 ' Concert (405 metres). 2.0, Chimes Relay and Time Signal. Programme. 7.15 (approx.), Concert, Opera or Concert by Play, followed by Late News Bulletin 2.5. the Station Orchestra : Midsummer All Times are reduced to Greenwich and Wireless Night's Dream (Mendelssohn) . (a) Scherzo, Notes and Sports Results. 10.30 (approx.), Close Down. Allegro appassionato, (c) Nocturne, (d) March. 3.80 Mean Time and are p.m. to 7.0, No Transmission. 7.0 Chimes. 7.5, Musical except Selections. 8.0, Talk and Reading : Famous Voyages where otherwise stated. TALLINN (403 metres) ; 2.2 kW. -7.30 a.m., Relay -Extracts from Thrilling Narratives of Interesting of Church Service. 5.0, Concert of Popular Music. Travels. 8.30 to 10.0, No Transmissiob. 10.0, 5.30 Talk. 6.0, Concert Programme. 9.0 (approx.), Chimes and Time Signal. 10.5, Musical Selections. Close Down. 12.0 Midnight, Programme of Dance Music by the cultural Communications. Palermo Orchestra, relayed from the Alkazar. 8.45, Gramophone Records TOULOUSE 12.30 General News (Radiophonie du Midi) (383 metres) : a.m. (approx.) (Monday), Close 7.80, Bulletin. 7.45, Radio Paris Circus. Down. 8.15, Programme of Music, 8 kW.-12.15, Wireless Agricultural Programme. Symphony rendered by 12.45, Concert. Soloists and Orchestra conducted by M. E. Bigot: L0, Time Signal, followed by Concert MILAN, MI (504 7 (contd.). 1.45, Latest News and Announcements metres) ; kW.-9.0 a,m., Opening in the Intervals : General News Bulletin and Evening Signal from Le ' and Lesson iu the English Language. 9.30 Press Review and Announcements. 10.30 (approx.), Télégramme," L'Express " and " Le a.m. to 10.30 a.m. (approx.), Concert of Sacred Music: Close Doctor. Midi Socialiste. ° 8.0, Stock Exchange Quotations Vocal and Instrumental Items. 11.30 a.m., Time and Cereal Market Prices from Paris. 8.15 ( approx.) News Signal. 11.32 a.m., Musical Programme by the and Announcements from ' La Dépêche " and Station Quartet. 3.0, Opening Signal POSEN (343 metres) ; 1.5 kW. -9.15 a.m. to 10.45 a.m. " Le Petit Partsien." 8.30, Concert of and Concert Relay of Morning Orchestral of Popular Music by the Station Quintet. 4.15, Service from Posen Cathedral. Music, arranged by the Association des commerçants 11.0 a.m., Time Signal. 11.15 a.m. and 11.30 radio-électriciens Programme by the Tzigane Orchestra, relayed from am., du Midi. Selections from ' Carmen" - the Fiaschetteria Toscana. Two Agricultural Talks. 11.55 a.m., Talk for Peasant -Opera (Bizet) founded on the 5.0 to 6.55, No Trans- Women. story by Prosper mission. 6.55, Opening Signal. 7.0, Press News 2.15, Concert of Symphony Music, relayed Merimée. At 9.0 in the Interval, Tima SignaL Bulletin. 7.15, Talk Sports Notes from Warsaw. 4.30 (approx.), Various Items. 4,50, 10.15 The Wireless Journal of North Africa and 7.25, and Results. Entertainment for Late 7.30, Time Signal. 7.35, Relay of " La Monacella Children. 5.20, Vocal Recital by News.and Announcements. 10.30 (approx.), Close Mlle. Marie Kisielewska (Soprano Soloist alla Fontana " -Opera (G. Mule) ; in the Intervals, from the Ddwn. Opera House) accompanied by. M. Talk ; Sports News and General News Bulletin. Sigismond Wojcie- chowski : 10.30 (approx.), Close Down. Aria from the " Magic.Flute" Opera (W. A. VIENNA (520 metres) ; 15 kW.- Programme relayed Mozart). 6.0, Report of the Catholic-Association of by Graz (354 2 metres), Innsbrues (455.9 metres), Polish Youth. 8.20, Programme from Warsaw. 6.45, Klagenfurt (455.9 metres), and Linz (250 metres). MOTALA (1,385 metres) : 30 kW.- Programme also Talk. 7.5, Programme of Miscellaneous Items. - for Stockholm (438 metres), Boden 7.30, 10.0 a.m., Concert Programme by the Vienna Sym- (1,200 metres), Musical Programme. 9.0, Time Signal. 9.5, Sports Notes phony Orchestra, with Göteborg (348.8 metres), Malmö (229 metres), Öster- Soloist Items. 3.0 Orchestral and Results. 9.20, Lesson in Dancing by Mr. Starski. Concert. 7.15, Relay of " Der Weltenbummler sund (720 metres) and Sundsvall (545.5 metres).- 9.40, Programme of Dance Music by the Orchestra "- 10.0 a.m., Relay of Morning Service from a Church of Operetta in The Acts. Book by Bede and Karl in the Palais Royal Restaurant. 11.0 (approx.), Close Lindau and Music by Richard Fall. Produced by Stockholm. 4.0, Entertainment for Children. Down. Victor Flemining 4.55, Relay of Carillon from Stockholm Town Hall. and conducted by Karl Lindau, followed by Programmes of Dance Music and Experi- 5.0 Relay of Evening Service. 6.5, Gotthold mental Ephraim Lessing Programme on the Two Hundredth RABAT, Call PTT (414 metres) ; 2 kW. -12.30 to Transmission of Pictures. 10.30 (approx.), Anniversary of his Birth. "Minna von Barnhelm" 2.0, Programme by the Radio-Maroc Orchestra. Close Down. Play (Lessing). 7.45. Programme of Choral Music. 4.0 to 5.0, Concert of Military Music. 8.15, " Le Journal 8.15, General News Bulletin Parlé." 8.30, Concert of Orchestral Music ; in the VILNA (427 metres) : kW. and Weather Report Interval 1.5 -9.15 a.m. to 10.46 and Forecast. 8.40, Orchestral Concert. 10.0 at 9.30, Sports Talk and Announcements by a.m., Relay of Morning Service from a Cathedral. (approx.), Close Down. M. Barrier. 10.30, Programme of Modern Dance 10.58 a.m. to 4.30, Programme from Warsaw. 10.58 Music from the " Chaumière de Rabat." 11.0 (approx.), a.m., Time Signal and Fanfare, relayed from the Close Down. Church of Notre Dame at Cracow. lie a.m., Aviation MUNICH (538.7 metres) ; 4 kW.- Programme relayed Routes Report and Weather by Augsburg (560 metres), Kaiserslautern Report and Forecast. (273 metres) ROME, Call IRO (443.8 metres) ; 3 kW. -8.30 a.m., 11.10 a.m., Symphony Concert by the Warsaw Phil- and Nuremberg (240 metres). -9.0 a.m., Evangelical Opening Signal, followed by German Language harmonic Morning Recital and Sermon. Orchestra. 1.0 to 2.0, Three Talks for 10.0 a.m., Chimes Lesson. 9.0 a.m. Recital of Vocal and Instrumental Agriculturists. 2.15, Concert of Symphony Music Relay from Munich Town Hall. 12.0, Time Signal, Selections o' Sacred Music. 9.45 a.m. to 12.0 Noon, by Weather Conditions the Warsaw Philharmonic Orchestra, conducted and Forecast and Survey of No Transmission. 12.0 Noon, Opening Signal. 12.5 by M. Z. Dymmka Concerto for Programmes of the Week. Recital Pianoforte in D 5.15, of Pianoforte to LO, Selections of Trio Music. 1.0 to 4.0, No Trans- Minor (S. Rachmaninoff), executed by Mme. Olga Music, rendered by Alexander Gunselmann, 7.0. mission. Opening 4.0, Signal. 4.5 to 5.30, Concert of Martusiewicz (Pianist). 6.45 (approx.), Time Signal. Concert Programme. 9.20, General News Bulletin. Popular Music. 6.50, News and Announcements and 7.30 10.10. Programme from 11.0 (approx.), Close Down. to Warsaw. 9.0, Report Press Review. 7.10 ( approx.) Agricultural Talk. on Aviation Routes, and Weather Report and Fore- 7.15, Sports Results and General Communications. cast. 9.6, News Bulletin supplied by the Polish Tele- NAPLES, Call INA (333 metres) ; 1.5 kW. -8,30 a.m 7.29, Time SignaL 7.31, Topical Talk. 7.45, Cele- graph Agency. 9.20 Police Communications and Lesson in the French Language by Prof. Etienne bration of the Anniversary of the Death of Giuseppe Sports Notes. 9.30, lance Music Programme relayed Verdier. 9.0 a.m., Recital of Religious Music. 3.45. Verdi: Requiem Mass for Soloists, Choir and Orches- from the "Oaza" Restaurant, Warsaw. 10.30 Children's Programme. 4.0, Concert of Popular tra, rendered by the Station Choir and Orchestra and (approx.), Close Down. Music. 4.30, Time Signal. 7.30, News and Com- Soloists; Choral Selection : Dies irae ; in the Irterval, munications. 7.50, Bulletin of the Reading. 9.50, Latest News Naples Harbour and Announcements. WARSAW 10 Authorities. (1.415 metres) : kW. -9.15 a.m. to 8.0, Time Signal. 8.2, Concert of Operatic 10.0 (approx.), Close Down. 10.45 Relay of Morning Service Music by the Station Orchestra, with the collaboration a.m. from a Cathedral. 10.55 a.m., Time SignaL 11.0 a.m. Relay of of Soloists: Fra poco a me ricovero, iron Lucia SCHENECTADY, Call 2XAF (19.58 metres) ; 30 Fanfare di kW.- from the Church of Notre Dame, Cracow. 11.5 a.m., Lammermoor (Donizetti), rendered by R. Rotondo 3.80, Relay of Divine Service from the Emmanuel Notes (Tenor), with Orchestral Accompaniment. Baptist Church. 8.30, Programme on Aviation' Routes and Weather Report and 9.0, by the Peerless Forecast. 11.10 Concert of Sports Review. 9.50, Calendar and Future Programme Reproducers from New York. 8.30, Recital of Organ am., Symphony Music, organised by the Department for Education and Cul- Announcements. 10.0 ( approx.). Close Down. Music, by Elmer A. Tidinarsh, from the Union College Memorial Chapel. ture of the Magistracy of Warsaw. 1.0 to 2.0, Three 9.0, Sermon tor Men, by Dr. Parkes Talks for Agriculturists. Meteorological Cadman, from New Recital of Music 2.0, Report. PARIS (Eiffel Tower), Call FL (1,488 metres) 5 kW.- York. 10.30, for 2.15, Concert of Symphony Music by the Violin by Arcade B'rkenholz, relayed from the Warsaw 7.56 a.m., Time Signal on 32.5 metres. -9,28 a.m., New Philharmonic Orchestra. 4.30 Talk. 4.55, Talk. Time Signal on 1,488 York. 11.0, Stetson Parade Programme, by the metres. 5.0, Relay of Pasdeloup 5.20, Concert of Popular Music . Spanish Serenade Concert. 7.10 to 7.20. Meteorological Report. American Legion Band, 'rom Boston, Mass. 11.30, 7.20, The Acousticon Programme (Al. Glazounoff), rendered by Mme. B. Prokoponcz Le Journal Parté. 8.0, Wireless concert, Vocal Selec- from New York 12.0 (Harpist) M. Gociawski Midnight, Relay of the Old Company's Programme, and (Violoncellist). 8.0, tion: Un petit eimtièrearabe (GeorgeTucca), rendered Miscellaneous Items. 6.20, Talk. 8.45, News and by Mlle. Mane Louise Welcome accompanied by the Vocal Selections by Reginald Werrenrath (Baritone), Announcements. from New York. 12.30 a.m. (Monday). Programme 6.58, Time Signal. 7.0 Twenty composer. 7.58, Time Signal on 32.5 metres. 8.50. Minutes of Intellectual Amusements. 9.0, Notes on Silent Night. 10.28, Time Signal on 1,488 metres from the Capitol Theatre, New York. 2.0 a.m., Relay of Lecture on " Our Government," David Aviation Routes and Weather Report and Forecast. by Lawrence, 9.6, News and Announcements from from Washington, D.C. 2.15 a.m., Atwater Kent the Polish Tele- PARIS (Petit Parisien) (336 metres) ; 0.5 Programme, graph Agency. 9.20, Police Communications and 8.45, Latest Gramophone from New York. 3.15 a.m. Correct Sports Results. Selections. 8.50, Talk. Time. 8.16 a.m., Programme by the National Light 9.30, Dance Music Programme, 8.55, General News Bulletin from the Press. 9.0, Opera Company, relayed -from the "Oaza" Restaurant. 10.30 Concert of Orchestral Music, relayed from New York. 4.15 a.m.. (approx.), Close Down. with the collaboration of Experimental Television Transmission. 4.30 Artistes from the Opéra and' Opéra-comique. 9.25, a.m. News and Announcements. (approx.), Close Down. 9.30, Concert of Sym- ZAGREB (308 metres) : 0.7 kW. -10.30 phony Music, conducted by a.m. Morn- Prof. Estyle of the Paris SEVILLE (Union Radio), Call EAJ5 ing Concert. 4.0, Programme of Light Music. Conservatoire. 10.0, Late News Bulletin. (370 metres) : 6.45, 10.15, 2 kW.-2.0 to 3.0, Concert of Popular Music by the Talk. 7.0, Opera relayed from the National Theatre, Concert of Orchestral Music : Fantasia on Madame Wireless Zagreb. In the Intervals : General News L'Archiduc (Offenbach).. Seville Orchestra followed by Latest Gramo- Bulletin 11.0 (approx.), Close Down. phone Selections. 9 30 Concert of Orchestral Music. and Weather Conditions and Forecast. 10.0 (approx.), 1LO. Flamenco Songs and Programme of Dance Close Down. - PARIS (Radio Paris) Call CFR (1,769 metres) : Music. 1L30 (approx.), Close Down. 15 kW. -8.0 a.m., General News Bulletin and Press ZURICH (489 metres) ; 1 kW. -10,0 Musical Review. 8.30 Lesson in Physical a.m., a.m., Culture, by STAMBOUL (1,200 metres) : 5 kW,-3.30, Orchestral Programme. 3.0, Concert by the Castellano Orchestra, Dr. Diffre. 12.0 Noon, Religious Address, followed by Concert. 4.30, Exchange Quotations Sacred and Cereal relayed from the Carlton Elite Hotel. 6.30, Time Festival of Instrumental and Choral Music. Market Prices. 5.15, Programme of Turkish Music. Signal. Protestant Sermon. 12.80, General News Bulletin. 6.32, 8.0 Relay of 12.45, Concert of 7.30, Weather Conditions and Forecast and Time Opera " Don Juan" (W. A. Mozart), relayed from Popular Music by the Albert Locatelli Orchestra: Signal. 7.40, Concert Programme. - Interlude 9.0, Genera the Municipal Theatre, Basle (on 1010 metres). by Bilboquet. 4.30, New Gramophone News Bulletin and Announcements. Overture to 9.0, Late News and Announcements, Selections, arranged by supplied by the "L'Industrie Musicale ": "The Czar and the Carpenter " Opera (Lortzing), Neue Züricher. Zeitung." 9.40 (approx.), Close General News Bulletin in the Interval. 0.80, Agri- 9.30 (approx.), Close Down. Down.

A 37 r' www.americanradiohistory.com Wpydsgo JANUARY 23rd, 029. T04 MpO). WII2ELESS WORLD LAB ORATORY TESTS

A Review of Manufacturers' Recent Products.

SCREEN FOR EUROPA M. pany, 2, Athelstane Mews, Stroud Green coil. Ebonite spacers support the Such component parts as might present Road, -London, N.4. primary coil, while all windings are difficulties of construction when building The aerial inductance is assembled on brought out to conveniently placed con - the Europa III are now becoming avail - an ebonite base very much in the manner necting pegs. Like the aerial inductance. ,.b!e. It is realised that the screen is shown in the article. A bakelised tube perhaps a. little intricate in its design, is used, and tinned soldering pegs provide for the aerial and earth connections. The loading coil, which is held down by an ebonite clamp, is a Brosse wave -wound inductance possessing good efficiency, and is entirely wrapped with a waterproof covering. Attractive appearance results from the use of polished ebonite insets at the ends of the former.

Europa Ill H.F. transformer (H. & J. Wireless).

the H.F. transformer is well finished. A receiver built from a set of these coils can be relied upon to function correctly Lock -Atkinson screen for building the and give a high standard of Europa III. 0000 performance. HUNT'S MEASURING INSTRUMENTS. and Lock- Atkinson Wireless, 107, Bol - sover Street, London, W.1, now manufac- The wide range of measuring instru- ture a screen tallying in all details with ments for which Messrs. A. H. Hunt, that used in the article. Ltd., are noted includes voltmeters, It is made from bard aluminium and is ammeters and milliammeters, functioning particularly robust, so that its faces are en the moving coil and electromagnetic perfectly flat. When used for the con- spring- controlled principle. The particu- struction of the Europa III the design lar instrument we have tested is a flush details can be followed in every way type panel -mounting milliammeter. This The H. & 3. aerial inductance as is a dead -beat moving -coil instrument without the need for any modification specified for the Europa III. of dimensions The price is 6s. 6d. reading up to 25 milliamps. and fitted with o c a 24-in. diameter dial. Tested against The H.F. transformer precisely follows a laboratory standard milliammeter COILS FOR EUROPA III. the design given, except that the loading the instrument showed a very small error, Following quickly on the introduction coil is totally enclosed within the cylinder but at no position was this greater than of this receiver, it was learned that a set and is protected by an ebonite end cap 2 per cent. As it will be extremely dif- of coils birilt to the design were obtain- which serves for carrying two small ter- ficult to measure to this degree of accu- able from The B. and J. Wireless Corn- minals conveying the connections to the i - ^y with any small size meter, for all A 38

www.americanradiohistory.com cY JANUARY 23rd, rg29. WIp®hoo 105 WOOFt110 practical purposes the reading obtained denser is priced at 7s. For low- pressure with the latter for valves of about 10,000 ohms. this instrument can be accepted as circuits the 300 -volt type A condenser is Although the a true indicatio-i performance cannot he ex- of the current flowing. quite suitable and in this model the 2 pected to equal that of the " Ideal'' It is interesting to note that the meter mfd. capacity costs 4s. 6d. range is of transformers, the difference could calibrated by hand, and this un- A number of small mica dielectric fixed be detected only by doubtedly :.ccounts a practised ear.. for the high order of condensers of the same make were tested, The measured inductance of the and in practically all cases the measured primary of the 2.7 : 1 transformer with- capacities were within 10 per cent, of the out D.C. flowing was 34 henrys and of marked values. The measurements ob- the 4:1 transformer 18.3 henrys tained with a few representative samples Both transformers are fitted with re- are tabulated below. versible feet and the price in. each case is 16s. Per- 0000 Type. Nominal Measured centage of Cap. Cap. Error. THE "EXACT" TUNERS mfd. mfd. Per cent. These tuners are designed to give a Con- Moulded bakelite tinuous overlap between 250 and 2,000 type 0.0002 0.000181 - 9.5 metres when 0.0001 0.000 319 -2.73 tuned by a 0.0005 mfd. con- Postäge stamp denser. They can be used, therefore, two 0.0005 0.000509 +9 as substitutes for the plug -in type of coil 0.001 0.000 993 -0.1 in Hunt's hand calibrated moving -coil meter. Midget moulded all positions in a receiver where coils The scale reads to 25 milliamps. condensers 0.0001 0.000102 +2 of this kind are usually employed. The coils are built up from sectional slab type accuracy. The measured D.C. resistance windings, each section being spaced from of the meter is 12.3 ohms and the price The prices of the moulded bakelite neighbouring ones by thin ebonite discs is 20s. range from ls. 6d. for the 0.0001 mfd. and a seven -point switch is built into the 0000 size to 3s. for the 0.01 mfd. capacity. centre of the coil assembly. A single hole POLYMET PRODUCTS. fixing suffices to hold the tuner rigidlly in position. Messrs. A. H. Hunt, Ltd., H.A.H. Works, Tunstall Road, Croydon, Surrey, have acquired the agency in this country for the Polymet radio products, which are high -grade American wireless accessories not previously available on this side of the Atlantic. They comprise a wide range of .components, but those which will appeal most to wireless enthusiasts here are the condensers and heavy duty

An assortment of Polymet " small fixed condensers. The postage stamp type is paxolin covered. The postage stamp type is slightly cheaper, the 0.0001 mfd. being is. ana the 0.01 mfd. 2s. 6d. Grid leak clips can be supplied for either type at 3d. per pair. 0000 MARCONIPHONE UNIVERSAL TRANSFORMERS. These transformers are made in two ratios-2.7 : 1 and 4: 1. The former is A set o: " Exact " tuning devices who suitable for valves having an A.C. rebuilt -in switches. sistance of 20,000 to 30,000 ohms, and On certain models a reaction coil is fitted, and in these cases it will be neces sary to drill a further hole to clear the control spindle. The reaction coil is carried on a spring hinge which tends to keep this coil tightly coupled to the main winding. Rotating the reaction control Two examples of " Polymet" !arge knob drives capacity condensers. the spindle backwards, and this, bearing against a conical shaped said wire -wound resistances. Under the first on the reaction former, moves this away heading are included some large capacity from the tuned coil. The action is in effect a slow motion smoothing condensers suitable for elimi- drive, and perfect control sheald be possible with this nators. The larger of the two illustrated arrangement. has a capacity 2 of mfd., and is tested to The aerial and anode withstand a pressure of 600 volts D.C. tuners with the reaction coil mounted on the anode coil A similar condenser tested to 1,000 volts is priced at 30s. the is available also for use in pair, and aerial coils high voltage only with reaction are listed at 14s circuits such as medium power transmit- The makers are the Exact Manufactur- ting sets or high voltage battery elimina- ing Co., Croft Works, Priory Street, tors. The 600 -volt type B 2 mfd. ton- alarconiphone ' Universal ' transformer. Coventry. A39

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rob WAp®IlQg0 JANUARY 23rd, 192g. WOpIl0 TiE PHYSICAL SOCIETY'S ANNUAL EXHIBITION. Some Interesting Apparatus Shown at South Kensington. T should be a source of gratification to all concerned with care had been taken to ensure good electrical " seals " at all wireless matters that workers in so many branches of science joints of the shielding cases. The method of tuning is attrac- are now bearing a share in the development of our own tive, being that of the Marconi naval receiver, already particular art. It is said that " science is measurement "; described in this journal. Complete ganging is found to be if this be true, the excuse for poorly designed apparatus is impracticable in a receiver covering a wide waveband (425- fast disappearing. At the Physical and Optical Societies' 1,100 metres in this case); instead, each of the three condenser Exhibition, held at the Imperial College of Science and Tech- dials are calibrated at " landmarks " every hundred metres or so, and, to tune in a given transmission, each dial is set at the nearest wavelength calibration. By operation of a fourth knob, the mechanically linked stators may then be swung through an arc of a few degrees. The facility for quick tuning thus afforded is important when bearings have to be taken quickly on a transmission of short duration. A signal strength measuring unit, covering wavebands between 14 and 5,000 metres, is another new product of the Marconi research laboratories. This contains an oscillator, of which the output can be made to coincide in intensity with received signals, and then measured. Another new Marconi exhibit was a tuning fork and-thermo- stat for controlling a synchronous motor. The interior of 4he box containing the fork is maintained at a constant temperature by an arrangement in which a tendency towards a rise beyond a fixed point causes a negative voltage to be applied to the grid of a valve, in the anode circuit of which a relay is inserted. This apparatus is used in synchronising transmitters and receivers operating on the " fac- simile " system. The new Marconi direction finder, with screened grid H.F.P The application of amplifying valves and semi- ganged tuning. the thermionic volt - nology, South Kensington, from January 8th to 10th (inclusive), metei is being ex- a variety of specialised electrical nteasuiug instruments were tended, and a range shown on a number of stands. of these instruments, Apart from apparatus produced by instrument makers, a for both high- and number of purely wireless firms were represented. Marconi's low -frequency work, Wireless Telegraph Company showed the new type 11G direction finder, which includes two transformer- coupled screened

Three units comprising a device by which incoming signals are compared with measured locally generated oscillations. (Marconi's W. T. Co.) were exhibited by the Cambridge Instrument Company, Ltd. Direct voltage calibration is provided. A new model has scales for measuring both peak and mean values ; it also gives an indication as to whether the applied wave form is truly sinusoidal. Another type has three ranges, with maximum readings of 2, 12, and 120 volts. The range of Ferranti measuring instruments now includes an A.C. microammeter giving accurate readings on speech - frequency currents up to about 3,000 cycles per second. It includes a Westinghouse copper .oxide rectifier, and reads up to 750 microamperes on full -scale deflection. This piece of apparatus should be useful in tackling some of the problems involved in L.F. amplifier design, and its price is low enough A Moullin type valve voltmeter by the Cambridge instrument Company. to bring it within reach of the amateur experimenter. Many wireless risers living in remote districts have to depend grid H.F. amplifying valves of the S.625 pattern. The on a primary battery for L.T. supply, and will be interested arrangement of this amplifier is interesting; each stage is, as in the Codd single -fluid gravity cell, relating to which a curve usual, completely screened, and it was observed that special was shown which revealed that, on a steady discharge of about A 40

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JANUARY 23rd, 1929. WHp®Il@OSI WopIlcl The Physical Society's Annual Exhibition. - The wavemeter can also be used as a master oscillator to 0.15 amp., voltage was maintained at an average value of over control or to check the wavelength of a transmitting station. 1.35 for more than 500 hours. The electrolyte contains ferric For check purposes the radio frequency of the muter is held chloride with pumice in suspension, which is precipitated and constant by a quartz crystal. A note of the same pitch as forms a coating ever the zinc electrode situated at the base the audio circuit is obtained by heterodyning the radio fre- of the container; this pre- quencies from meter and transmitter. If the latter frequency cipitation serves the same alters, a slow beat will occur between the two audio frequencies, purpose as a porous pot. The which can be made visible on a meter. cells can be recharged at low The wavemeter is quite inexpensive and sells cost. at £4 15s. (without screened grid valve). It The Marconiphone Company showed a new power unit, type D.C.B., for operation on D.C. supplies of 200 volts or over.

A Ferranti A.C. microammeter. This comprises a pair of P.625 output valves in push -pull, and the necessary voltage- reducing apparatus, etc., to enable them (Above) Marconiphone D.C. mains output unit to derive H.T., L.T., and grid bias voltages from the mains. with push -pull valves and lamp resistances. The unit is intended for connection to an existing set when it (Right) The Lucas quartz resonator shown by is desired to increase output for operating a moving coil loud- H. W. Sullivan. Being mounted in vacuo, fric- speaker or other reasons. tional loading, air loading and dielectric hysteresis errors are itlmost entirely avoided. A new Ediswan short -wave transmitting valve has a special form of base arranged to reduce self- capacity. A plate ter- the advantage no heterodyne oscillator is required,' minal is mounted on the -top of the has great that bulb. The makers since a modulated wave is produced with only one valve without also exhibited an L.T. supply unit. the use of a reaction coil; furthermore, the calibration is independent of the valve. The latter is a very important feature, The Fuller L.T. battery trickle charger, since it is possible, by using special coils and condensers, to con- already described in this struct a wavemeter of great accuracy for precision measurements. journal, has been modified by the Another instrument of importance on this stand was the Lucas substitution of an improved transformer. quartz resonator of 100 kilocycles frequency. It is now common The firm also showed a knowledge that the orthodox quartz resonator cannot be relied range of inert dry cells. The upon as a frequency standard to better than one part in 3,000 British Metalising Com- unless special precautions be taken in the mounting. The model pany, which exploits a process by means of which a metallic coating may be made to adhere firmly to a non- metallic base, such as ebonite, had exhibits showing the application of their method to the constiuction of wireless apparatus. An exhibit of especial interest to the wireless listener and to those interested in precision measurements was the McLachlan-Sullivan modulated C.W. wavemeter shown by Messrs. H. W. Sullivan. This instrument is the invention of Dr. N. W. McLachlan and depends upon a new electrical effect. When the anode voltage of a screened valve is less than that of the screen the valve has a negative resistance. In the anode circuit a coil and con- Codd single -fluid cell. denser tuned to a radio frequency are connected in series with a similar arrangement tuned to an audio frequency. With suitably proportioned coils and condensers a radio frequency modulated by an audio frequency is obtained. If this modulated C.C. wavemeter is placed near a radio receiver the audio frequency is reproduced by the loud speaker, provided the receiver circuits are tuned to the wavemeter. Thus a receiver can be tuned without the aid of a transmitting station. Alternatively, if the re- The McLachlan-Sullivan modulated C.W. wavemeter. A screened grid valve working on the negative -resistance portion of the ceiver is tuned to an unknown station its wavelength can be characteristic is employed to produce oscillations so that no found at any time, even when the station is shut down. reaction coil is needed. }r

www.americanradiohistory.com ios WilpISIlMg JANUARY 23rd, 1929. WOpIl6 The Physical Society's Annual Exhibition.= By mounting these devices in small cradles actuated by a exhibited is mounted in vacuo, resulting in the reduction to solenoid consuming but a few milliamperes, it is possible to negligible proportions of the normal errors produced by fric- make or break about 5 amperes with a tilt of 6 °. The price tional and air loading and by dielectric hysteresis. Absolute of the single -pole single -throw switch illustrated is 2s. 6d. stability as regards readings can be produced within one part An extremely interesting demonstration of the various pro- in 250,000 indefinitely. cesses involved in the rectification and smoothing of A.C. mains This company also exhibited a wide range of laboratory to provide H.T. current for a receiver was given by Messrs. apparatus for the standardisation and measurement of radio MuIlard and Co. Meters were interposed after each successive frequencies. The modern ultimate standard of frequency is filter component and a diagram showing the decreasing ampli- a valve- maintained tuning fork having a frequency of 1,000 tude of ripple current was given. The large current (about per second accurate to a few parts in a million and having a 80 mA.) passed by an`early smoothing condenser as registered temperature coefficient of the same low order. One of these by a thermo- ammeter was of interest, but it should be pointed was shown together with the specially designed valve- driven out that this is not a serious load on the rectifier, as the current phonic wheel. This wheel is run up to the synchronous speed under these circumstances is practically wattless. The Mullard as a self -driving motor by means of two electro- magnets connected to the input and output of a three -valve amplifier. A small E.M.F. is taken from the fork whose frequency is being determined, amplified by another three -stage amplifier and applied to another driving magnet of the wheel, which then runs as a pure synchronous motor. A contact operated by the wheel impulses the pen of a chronograph at each vibration of the fork, which can thus be compared with the standard clock also operating the chronograph. The frequency of the fork can be determined to within 0.001 per cent. by running the wheel synchronously for 1,000 seconds. In the sub -standard wavemeter section of the exhibits of A Messrs. Sullivan were to be seen the Sullivan -Griffiths precision variable condenser, the latest design of which is described by W. H. F. Griffiths in the present issue of " Experimental Wire- less." For use with condensers such as this, W. H. F. Grif- fiths has designed inductance coils having negligible temperature coefficient, and the first of these to be constructed was also exhibited. The principle employed is that of constructing the former from insulating materials having different tempera- Two examples of the Isenthal mercury switch suitable for remote of linear in control relay work. Contact is made between mercury and ture coefficients expansion such a manner that the mercury in a non -oxidising atmosphere. With A contact is made diametrical and axial thermal expansions compensate in their with a tilt of 10 °, with B a tilt of 25' is necessary. effect on inductance value and at the same time will not permit the winding to loosen. power output valve -the D.0.20- consuming L3 amperes at Many attractive remote -control relay schemes for L.T. and 7.5 volts should appeal to those employing moving -coil loud moving -coil field current switching can be evolved with the speakers. An H.T. voltage of 425 can be applied to the anode small mercury switches shown by Isenthal and Co., Ducon and an impedance of 1,700 ohms, together with a magnification Works, Victoria Road, North Actors, W.3. Consisting of sealed factor of 5, gives the satisfactory mutual conductance of about glass tubes containing an inert gas, these switches are so 3 under amplifying conditions. There is a new full -wave rec- arranged that contact is always made between mercury and tifying valve known as the D.W.8 giving a D.C. output of mercury, resulting in the contact resistance remaining un- 60 mA. changed over a period of time, which is not the case with It is now well known that with certain loud speakers the metallic contacts exposed to varying atmospheric conditions. pentode gives a predominance of the higher frequencies due to its comparatively high impedance. To arrange a suitable matching of impedances the Igranic Co. are now manufacturing a tapped output tranformer known as the Pentoformer, which was exhibited. Another component of interest on this stand was a new mains transformer designed to precede a metal -oxide rectifier.

For use in standard wavemeters this inductance is wound on a former of such material that diametrical and axial thermal expansions compensate in their effects. Designed by W. H. F. An H.T. eliminator for A.C. mains with spaced components demonstrated by Mallard. Meters Griffiths and shown by H. W interposed in the various filter circuits indicated the amplitude of A.C. and D.C. components, Sullivan. while a schematic diagram attached showed the successive changes in waveform. A 42

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JANUARY 23rd, 1929. Wilpagoo .T09 WcmIld

NEWS FROM ALL QUARTERS.

By Our Special Correspondent. A Television Broadcast. -New Wavelengths on Trial.

Truth and Television. quency. Decidedly less interference is supposing that the van does not confine Some of the cynics will exclaim at the noticed at the majority of stations, its attentions to oscillators. apparent incongruity of the above title, though Newcastle, which dropped to the e000 alleging that the two terms have not so prodigiously low wavelength of 243.9 High -power Broadcasting for Ireland. far shown signs of harmony. in- metres, reports " slight interference, but The Irish listeners are expecting an official credulous, not excluding a Savoy Hill not more than before the change." 0000 announcement shortly regarding the . contingent, exclaimed in the same mooted high -power broadcasting manner when The Wireless World made Will the Common Wavelength Scheme station, Succeed which is to be similar to the stations of a prophecy in these columns on 7 the B.B.C. November regional scheme. The pro- 7th last concerning the proba- Only Bournemouth and two of the re- posals have been submitted by the Post bility that a B.B.C. station would lays-Bradford and Edinburgh -are at shortly lent Office to the Ministry of Finance, and be to the Baird Company present on the national common wave- are now awaiting the consideration of for experiments in the early morning length of 288.5 metres, which is ulti- Dail. Fours. the I hear that several possible mately to be shared by all the relays. sites have been explored, technical "Impossible ! will " they said, fortified by Hull prebably follow next. On this opinion being in favour of a central posi- the official announcement that the tests wavelength there has already been tion in the Queen's were " off." County or Tipperary 0000 trouble, due to " wobbling " on the part districts, midway between Cork and of Bournemouth. This is not a happy Dublin. A New Decision. augury for the common wavelength 0000 arrangement, for if three stations cannot \Vas it generally realised, however, A Vicious Circle. that the B.B.C. decision constituted a avoid jostling one another at such distances, what will happen when there are Only a heart of granite could remain rebuff to the Post Office? The engineers unaffected of that much-maligned institution had ten ? by the touching New Year expressed the opinion that the Baird It appears that only " knife edge " message which the Indian Broadcasting system was worthy of tests, tuning can make a common wavelength Company prints in the Indian Radio and, as can Times. easily be imagined, St. Martin's -le -Grand practicable. Unlike the B.B.C., the I.B.C. is was 0000 never in possession of more capital than not altogether pleased when its own it opinion was cast aside. Trouble on the Continent. knows how to spend. It has never bad enough to spend, and the With these reflections in mind, it is not On the Continent conditions are less result is happy. that, in the words of its directors, it so very difficult to account for a new A calibration trip all round the " moves B.B.C. decision, unannounced, to give dials shows that the European stations in a vicious circle." The I.B.C. gets its revenue from the system a broadcast trial next month. almost without exception are making a licence 0000 loyal effort to adhere to the new fees, but the receipts from this scheme. source are lamentably small, A Stealthy Test. Unfortunately, their zeal is greater than because the their technical public is waiting for the programmes to I am able to state that, unless some- attainments. improve before buying The separation of only 9 kilocycles sets and licences. thing unforeseen occurs, a television test And the company can only improve the will take place at one of the Daventry between the frequencies allows a very programmes small margin of safety, and although when it gets more stations early in February. The trans- money . . . ! mission will, of course, be made at a every station is provided with a Brussels 0000 standard time when most other European stations wavemeter, a good deal of Fatal heterodyning is still going on. Optimism. are out of operation. This point is of Faced with this the utmost importance, for it is common 0000 " unfortunate situa- knowledge Interference with 2L0. tion," the company appeals to all classes that the frequency bands rein India to buy receivers quired for television are sufficiently ex- in large There has been a pronounced hetero- numbers. If the public will do this the tensive to wreck all the European fre- dyne on 2L0 during the last two weeks. company promises, quency schemes ever invented. on its part, to extend 0000 Many readers must have noticed it. The the scope of the programmes beyond the offender is believed to be Graz, which is present gramophone The New recitals and one -man Wavelengths. now supposed to be working on 354 performances on the umpty- tum -tum. The Plan de Bruxelles, which takes no metres. 2L0 itself is not straying ; the Fatal optimism ! As well expect the engineers will swear to that ! cognisance of such a thing as television, coon public to buy tickets for National Con- is proving fairly satisfactory in the concerts at the Queen's Hall on the under- ditions for which it was intended. On the Black List P standing that the concerts will not be so So far as the B.B.C. are concerned, A Blackburn reader tells me that there bad if sufficient tickets are taken. The the new wavelengths are causing no has been a scurry towards the Post Office man -in- the - street refuses this kind of lot trouble beyond the fact that each station counters in his district following the ap- tory. The I.B.C. will have to learn the has to pay greater attention than ever pearance of the G.P.O. anti- oscillation hard lesson that in matters of broadcast- to the maintenance of its exact fre- van. Apparently there are grounds for ing the demand follows the supply. A -13

www.americanradiohistory.com ZIO Whp® Dmo JANUARY 23rd, 1929. WOpllcl

r RS TOO 111 , H 1iJ EDITOR. The Editor does not hold himself responsible for the opinions of his correspondents. Correspondence should be addressed to the Editor, " The Wireless World," Dorset House, Tudor Street, E.C.4, and must be accompanied by the writer's name and address. ECHOES. Although the listeners' ear is still the final judge, it would Sir,-With reference to your recent article on the " Long - no doubt bring to his notice the deficiency of his set could a interval Echo on Short Waves," I would like to report an programme as outlined be transmitted as a guide. excellent echo on station PMC (ex ANC), Java, at 10.30 It is further suggested that in the event of improved recep- G.M.T. on Saturday, January 5th. This station was R8 with tion following on such experiments, listeners would use their a 1 sec. (approximate) echo at R3 -4. sets more frequently as there is no comparison between listen- To illustrate the time interval, I might add that, in the call ing to a medium class of set and a set capable of natural PCG de PMC, the " de " could distinctly be heard twice at reproduction, and it is thought that many a selection is con- about 20 w.p.m., the effect persisted till about 11.30 G.M.T. demned mainly because the receiver is not capable of rendering Incidentally, one can also report very excellent L.S. recep- the complete programme transmitted, to the detriment of tion every Wednesday of the two Bandoeng telephone stations, quality. C. R. MASON. ANE and ANF. Kenley, Surrey. One wonders that more relaying is not done on the 17 -14 metre band, which seems to be excellent for daytime work for listances over a few hundred miles, though PCLL cannot EMPIRE BROADCASTING. be heard on 18 metres. Possibly this is too near. King's Lynn. EDWIN J. ALWAY, Sergeant, R.A.F. Sir, -My mail this Christmas week consisted of, among other matter, (1) your paper, (2) Daily Mail Year Book, a letter from a friend, and (4) World Radio. I wish to deal with these NEW YEAR RESOLUTIONS. in turn : Sir, -I noticed sundry suggestions for New Year resdlutions (1) Your paper has alone fought the case of Empire broad- in your January 2nd issue, and I would like to emphasise, if casting, and good luck to you. you_ can spare the space, the very bad practice at present in (2) Page 249, " Year Book," contains an article, and in the vogue amongst the valve makers of publishing particulars of second paragraph and in bold type is the following : " 5SW valves which they apparently have no intention of ever trying is a very great Empire propaganda station and . . . that the to put on the market. This happened with one firm in 1927 Dominions should contribute something to the upkeep of over the 6 -volt screened grid valve ; the same firm this year 5SW....,. published particulars of a special super -power valve at the (3) The letter contained the news that 5SW had changed its Show, and are only now starting to produce them. Another wavelength to 25.53. equally well -known firm have done the same this year over a (4) As I have not been getting 5SW for some time, I thought 6 -volt screened -grid valve, and can give no date of delivery, this had happened, and the change is noted for the first time and frankly own that none has been made yet. in World Radio. However, I note that this famous Empire The valve makers are not the only ones to blame in this station has still a holiday on Saturdays and Sundays. natter, but they are by far the worst. The others do produce Now let us have a few home truths. First, we Coicniais the goods in the end. visit the Homeland in thousands yearly. We buy sets and If you could obtain a list of all makers' valves that can licences and use then for a few months, and on return to actually be bought on, say, February 1st, and publish this " our respective spheres of influence " we pay a fee also for together with the same makers' lists as published at the Show, our own broadcasts, plus customs, etc. While at home I paid you would be doing a great service to fix public and to the nothing to Hilversum or Radio Paris, and I am ashamed to trade. GUY S. M. ASHBY. say PCJ has asked me for nothing towards the upkeep of their Hermitage, Bucks. station though I am a regular listener -in and have been long before 5SW was thought of. The sentiment expressed in the extract I note smacks of " shopkeepers," as Napoleon called STANDARD FREQUENCY BROADCASTS. us more than a century ago. Secondly, where is this pro- Sir, -In these days when purity of reproduction is, with paganda, when a Marconigram weeks ago would have put us roost listeners, a matter of paramount importance, and when right as to : change of wavelength? What do we know of such great pains are taken with both receivers and loud Christmas programmes ? Being in the wilds I go to church speakers, it seems a pity that the final judgment should still either to Calcutta or Bombay, sometimes Sydney, and more be left to the listeners' ear as to the efficiency of his receiver often Nairobi, but never do I hear St. Martin's or any other or speaker and as to its capability of reproducing the various London service. I hear 2XAD experimenting with 5SW, but notes of the musical scale as transmitted. not vice versa. If I were sure of 5SW at 11.30 p.m. and after It would seem to convey an obvious benefit amongst the (Indian standard time) I might spend some nights at the game, searchers for natural reproduction could they be provided with but why should the engineers of 5SW have a rest after the C L standard of comparison. 1.30 hour (G.M.T.)? Last evening (Christmas) I tried all I It is suggested, therefore, that a short period should be knew to get the lunch -hour music, but nothing doing. I devoted some time during the evening programme to the trans- honestly believe that the veriest " fan ' in England would mission of separate notes of the scale with their accompanying object to any broadcast confined to midnight hours of the week, names, the named notes to be more especially those at the for be it understood that on the days when we could revel in extreme ends of the scale, as it is quite probable that many this way they down valves and turn off the juice -at 5SW. receivers would not respond at all to the extremely high and PCJ always lets us know in the Press, days before, any low frequencies, and listeners would not be conscious that they change in programme hours, and I may remark that on their had missed part of the transmission without the accompanying broadcasting days my loud speaker at full strength with fading announcement. only after 8 a.m. gives me a perfect gramophone concert. PCJ Further to the above scheme, it is suggested that the pro- does not pretend to do anything else. We are glad to send gramme could be extended to include the transmission of a few them reports. The League of Nations has selected Hol- Lars of music consisting of notes from the highest and lowest land for world -wide broadcast. England wants an 'Ether ends oI the scale with a chord or two from the middle by way Blake at the microphone of 5SW, so Mr. Editor, please ,find of a comparison. one before any more talk takes place and before the whole of Again, various musical instruments could be played and the 0.1 per cent. of the B.B.C. revenue for next year is frittered named during the transmission as a further guide to the away on this Empire monopoly. efficiency of the set in natural reproduction. Roorkee, India. RADIOX. A 44

www.americanradiohistory.com JANUARY 23rd, 1929. VrApasoo GNIopIld ( /i//

The Service is subject to the rules of A selection of queries of general the Department, which are printed -_ interest is dealt with below, in some below; these must be strictly enforced, 'ANSWERED cases at greater length than would be in the interest of readers themselves. possible in a letter. " The Wireless World rr Supplies a Free Service of Technical Information.

Gramophone Amplifier. anode resistances, potentiometers, etc., Three H.F, Stages. the Will you refer me to a published descrip- short-circuiting connection between Is there and real reason why I could not the phone terminals must be removed, tion of a gramophone amplifier and add a third stage to the Kilo - a pair phones H.F. " capable of giving reasonable volume of connected in its place. Mag Four " receiver, the idea being with high quality? M. W. T. The course of procedure is now similar, to use a small frame aerial? A three -valve amplifier with low -gain M. V. J. stages designed to load up an ordinary A three -stage H.F. amplifier with super -power output valve was described screened grid valves is not impossible, but with full details in The Wireless World there are considerable obstacles in the for March 14th, 1928. This instrument way of its satisfactory realisation. For would appear to be quite suitable for instance, all circuits should be completely your purpose. 0000 decoupled and screened, and in particular you should pay careful attention to the A Combination Set. separation of H.F. and L.F. components I propose to use the coils and switching in the anode circuit of the detector valve. arrangement as described for the Also it would perhaps be best to satisfy " Europa III " in the " Megavox," yourself with an amplification per stage in order to receive medium and long somewhat less than that of the receiver to wavelengths without changing coils. which you refer. Is this possible? J. D. M. S. o 000 Yes, the plan you propose is quite practicable, but you will probably find it An Economy Measure. convenient to omit the alternative rectifi- Why is it that-it is always recommended cation switch, and to make the detector that valve filaments should be con- Fig. 1. -An Invaluable aid In tracing nected in series when they are to be operate on the grid circuit principle only. faults: a simple testing unit. 0000 fed from a D.C. mains suppl y ? Surely it would be much simpler to A Testing Unit. except that continuity will be indicated retain the ordinary parallel connec- I believe it is possible to make up a simple by a click -of an intensity depending on tion; if this were done, a conventional and inexpensive unit whereby a the resistance of the external circuit -in receiver could be connected to the receiver may be tested for defective the telephones. The click will only be mains with no internal alteration. produced when the circuit " connections, etc., a flash lamp or is made " or E. S. broken, but an S: pair of phones being used as an indi- intermittent disconnection The point here is it. is more is often revealed by that much cating instrument. 1 f so, will you a scratching sound. economical to adopt the series connection, please give me a circuit diagram of a because there is always a large surplus suitable arrangement? H. G. C. voltage to be absorbed in an external Various simple devices of this sort have RULES. resistance. Assaming that all the valve described been from time to time in this (1.) Only one question (which must deal with filaments consume the same current, it journal. We think you will find the a single specific point) can be answered. Letters costs no more to supply a five -valve set arrangement given in Fig. 1 to be most must be concisely worded and headed " Infor- than one with a single valve, provided useful,- properly handled, it is capable mation Department." the filaments are joined in series. With of revealing the great majority of faults. (2.) Queries must be written on one side of the paper, and diagrams drawn on a separate the parallel method of connection, the As a rule, the flash lamp will be used sheet. A self -addressed stamped envelope must five -valve set would consume five times as to test circuits and components which be enclosed for postal reply. much current as the other. have (or should have) a low D.C. resist- (3.) Designs or circuit diagrams for complete o o o o ance : to apply this test, the TEL. ter- receivers cannot be given ; under present -day conditions justice cannot be done to questions Variable Condensers. minals must be short- circuited, and test of this kind in the course of a letter. applied across the points between the set which ai a about to con- leads (4.) Practical wiring plans cannot be supplied For I which continuity is doubtful. If the lamp or considered, struct, the designer specifies logarith- glows at full brilliancy it can generally be (5.) Designs for components such as L.F. mic condensers. Now I have on hand taken that everything is in order. Occa- chokes, power transformers, etc., cannot be one of these, and another with square sionally it is necessary to test through supplied. law vanes. Is there any serious ob- the windings of a tuning coil which, if it (6.) Queries arising from the construction or jection to using then? S. M. operation of receivers must be confined to con- has a large number of turns, may have a structional sets described in The Wireless If both condensers are to be used for resistance of several ohms. In this case World " or to standard manufacturers' receivers. tuning purposes, the only disadvantage the lamp may glow less brightly, although Readers desiring information on matters will be that it will be impossible to there is no broken connection. beyond the scope of the Information Depart- arrange matters so that the dials are more high- resistance circuits, ment are invited to submit suggestions regarding For testing such subjects to be treated in future articles or or less " in step " over the tuning scale as the windings of L.F. transformers, paragraphs. This is not a very serious disadvantage. A 45

www.americanradiohistory.com Il? WATch7oo,.s JANUARY 23rd, I929. VVDSIql Eliminator Output Voltage. Loud Speaker Polarity. . Long -wave "Everyman Four." H ;7( it be safe to connect the " power " In wiring a receiver in which, the loud Have you published instructions for modi- terminal of my D.C. eliminator to a speaker is connected directly to the fying the original " Everyman Four" pentode valve, for which a maximum anode of the last valve, how should to include H.F. amplification of the voltage of 150 is specified? I hesitate the terminals be connected? long wavelengths as well as on the to try this, because I believe that in A. W. S. medium band? R. A. L. some eliminators the " power " ter- One of the loud speaker terminals will No specific instructions on this matter minal delivers the same voltage as be joined directly to the plate of the have been published, but where it is that of the mains -in my case 240 valve; this will be the negative, while desired to modify the set it is recom- volts. V. T. L. the positive terminal will be connected to mended that the general arrangement and Without any data concerning the the positive side of the.H.T. battery. layout of the " Standard Four " (The arrangement of your eliminator, we fear o 000 Wireless World, November 30th and is quite impossible help you. is it to It H.F. Stage for a Portable. December 7th, 1927) should be followed. usual to include some means of reducing o O o O 1Vill you please give me a circuit diagram the mains voltage, but, to be on the safe An Unstable " A.C.3." side, we think you would be well advised of a screened grid H.F. amplifier to get in touch with the makers of your suitable for inclusion in a self -con- lily A.C.3 receiver, built from the eliminator. tained receiver with a frame aerial? description published in your issue of 0000 I intend to follow the amplifier by a September 5th, 1928, cannot be neu- An R.C. Coupler. grid circuit detector with reaction, tralised properly over more than half and like to use the tuning scale. Can you IVhetì a commercial resistance -capacity should transformer suggest coupling. To avoid complications, what is wrong? 1 have used coupling unit is used, is it possible to I a cabinet propose to restrict myself to the of slightly different dimensions from ;. insert an H.F. stopping resistance in medium broadcast that specified, but the the grid circuit of the first L.F. valve waveband. departure from E. W. T. the original layout is not considerable, without taking the unit to pieces? I The of a although it has been ask this because it seems to me that circuit diagram suitable necessary to arrangement is given in 2. move the aerial -grid coil there is a good deal of H.F. energy Fig. It will and the H.F. be necessary to screen the H.F. stage, transformer. There is no alteration in my L.F. amplifier; when the loud in the circuit arrangement. speaker terminals are touched.the set goes into oscillation. R. P. H. Accordingly, I In a receiver of should like to do something to make H.T.t TO L.F this description, in which coils of low H.F. resistance are the apparatus more - stable. used, it is important F. W. K. that the relative posi- c tion of the inductances should be suitably It is quite unnecessary to make any in- chosen, and you ternal alterations to your unit, provided FRAMEn ^ .. must align them as in the t) original set. Other readers have reported it is of the conventional type. All you failure when have do is the design has been modified to to connect the present ter- o°Ì T' _ in a similar way. minal marked " grid " to one side of the .... 0000 stopping resistance, and to join the other R.C. .... L.F. Reaction. side to the grid terminal of the valve - holder. 117ten I increase I1.'1'. voltage beyond 0000 about 36 volts, a low howling sound is emitted from Choke Coupling. my loud speaker; naturally, with a smaller applied volt- I have an L.F. choke rated at 30 henrys, age, quality and volume are poor. and would like to use it for coupling Front this information, can you an tell anode bend detector to the first me -what is wrong? H. S. W. L.F. stage. Do you think it will be We expect that your battery has a high suitable? The valve has an im- internal resistance, and that L.F. reaction pedance of 60,000 ohms. M. H. L. is taking place. of 1 Short replacing the Generally speaking, we think that the battery, you might try the effect of re- choke has an insufficient inductance for versing the primary connections of one your purpose. It is assumed that you Fig. 2.- Screened grid H.F. stage with of the L.F. transformers (if these are refer to the rated impedance of the valve frame aerial used), or, alternatively, you could instal under artiplifyirig conditions ; 60,000 ohms the anode feed resistance scheme. is distinctly high, and it must not be for- and if you are aiming at high amplifica- It is just possible that some of your gotten that this figure will be increased trouble may be due to microphonic action, when the valve is biased for detection. tion, you will probably find it easier to 0000 attain complete stability if you include and you should try the experiment of the decoupling devices which have been placing the loud speaker at a distance from No Grid Bias. described from time to time. the receiver. My ' New All -Wave Four," after work- 0000 ing satisfactorily for a considerable The Most Suitable Milliammeter. tinte, has developed a fault; quality Choice of H.F. Valve. Will you give me a word of advice as to has become very bad, and I notice ll'ill you please tell me if the H.L.610 the best type of milliammeter to pur- that the plate current consumed by valve, reviewed in your issue of chase? The main use to which it is the last valve has risen to almost January 2nd, will be suitable as an to be put is for measuring the current double its previous value. H.F. amplifier in the " New All - passed by the output valve, and for P. M. R. Wave Four," or would it be better to detecting-distortion, but I should like We think it almost certain that the fault choose a valve with lower impedance? to obtain an instrument with as wide will be found in the grid circuit of the B. H. C. a range of usefulness as possible. output valve, as it appears that this valve This valve should be entirely suitable, E. B. R. is not getting the necessary negative bias; and in your geographical situation (close Unless you are using an output valve of consequently its anode current has in- to a broadcasting station) we would cer- exceptionally low impedance, with an ab- creased. You should accordingly make tainly not recommend a valve of lower normally high anode voltage, we consider careful tests of this circuit, paying atten- impedance, as this would tend to reduce that a meter reading up to 30 milliamps tion to the transformer secondary and the selectivity. In any case, the impedance is likely to be most generally useful. A grid bias battery, which, of course, may of the valve in question approximates two -range instrument is also to be recom- itself be at fault. closely to the value usually recommended. mended. A 46

www.americanradiohistory.com AN D RADIO REVIEW (16 fh Year of Publication)

No. 492. WEDNESDAY, JANUARY 30TH, I929. VOL. XXIV. No. 5.

amenable to discipline, in that they could be directed Editor: HUGH S. POCOCK. almost in the form of a beam, and this property has Assistant Editor: F. H. HAYNES. been utilised in the development of the beam short -wave Editorial Offices: xió -117, FLEET STREET, LONDON, E.C.4 transmitters, with special aerials designed to concentrate Editorial Telephone: City 9472 (5 lines). the energy transmitted in orte direction. So far, we Advertising and Publishing Offices: DORSET HOUSE, TUDOR STREET, LONDON, E.C.4. believe, little attempt has been made to adopt the same, Telephone : City 2847 (x3 lines). Telegrams : "Ethaworid, Fleet, London." or similar methods, in the case of the longer wave- COVENTRY : Hertford Street. lengths ; it would seem is scope for experi- Coventry. that there Telegrams ' " Cyclist, Coventry." Telephone: 6210 mental work in this direction, though the cumbersome BIRMINGHAM : Guildhall Buildings, Navigation Street. Telegrams: "Autoprese. Birmingham." Telephone: 2970 and 2971 Midland. nature of the aerial system which would be required MANCHESTER : 260, Deansgate. might bring us to the conclusion Telephone: 8970 City (4 line,) that it was not worth Telegrams: "Lifts, Manchester." while in practice. GLASGOW : 101, St. Vincent Street. C.2. Telegrams: " Tli0e, Glasgow." Telephone: Central 4857. Now, with the development of broadcasting, a very PUBLISHED WEEKLY. different problem is involved. The last thing that is Subscription Rates: Home, z7s. 4d. ; Canada, z7s. 4d. other countries abroad, z9s. 6d. per annum. required of a broadcasting aerial is that it should have Entered as Second Class Matter at New York, N.Y. any directional properties ; on the contrary, it is desir- A s many of the circuits and apparatus described in these pages are covered by patents, readers are advised, before making use of them, to satisfy themselves able that it should radiate in all directions with approxi- that they would not be infringing patents. mately equal intensity. It is easy to see that a broadcasting station on this account alone, and leaving out CONTENTS OF THIS ISSUE. of consideration altogether the question of the wide PAGE frequency EDITORIAL VIEWS ...... 113 band required for broadcasting purposes, is THE THEORY OF PUSH -PULL. BY N. W. MCLACHLAN .. 114 more liable to cause interference with neighbouring SYDNEY TALKS TO NEW YORK ...... 110 USEFUL DATA CHARTS (No. 21) ...... 120 stations than transmitters of other types. In wireless 123 PROGRAMMES FROM ABROAD ...... 124 transmission we may describe the radiation from the BROADCAST RECEIVERS. GECOPHONE WORLD -WIDE SCREEN GRID FOUR 128 transmitting aerial as divided into two ONE METER MANY PURPOSES (CONTINUED). BY A. L. M. SOWERBY .. 131 components, the 134 horizontal or ground radiation and the vertical radia- BROADCAST BREVITIES ...... s .. 136 VALVES WE HAVE TESTED. MARCONI AND OSRAM 5.216 VALVE . 137 tion. It has been found that the range of a station is LETTERS TO THE EDITOR .. .. 138 improved in proportion as the intensity of the vertical READERS' PROBLEMS...... 140 radiation is increased, but that if the design of the aerial can be such as to limit the vertical radiation and confine AERIALS FOR BROADCASTING STATIONS. the radiated energy to the horizontal component as far THE record of the development of aerial systems as possible, then the intensity of the field around the for transmitting stations provides quite an interest- transmitter is increased, but. the range is limited. ing little history of its own, and dates, of course, It is considered by some authorities that this latter from the earliest attempts at wireless communication. arrangement would be ideal for broadcast transmitters, Sinçe most of us are now concerned with broadcast and a paper recently read before the Institution of Elec-

reception when it is unnecessary,. for ordinary purposes, trical Engineers by Messrs. P. P. and T. L. Eckersley to pay very particular attention to the aerial system, we and H. L. Kirke discusses the problem of the design of are apt perhaps to look upon the aerial as the least broadcasting aerials where the endeavour is to realise interesting part of wireless equipment, and to forget this objective. that its design, in the case of 'transmitting stations, at There are, of course, many arguments which can be any rate, may be of the utmost importance. advanced in support of such a proposition, but, on the In the early days of transmission, before telephony or other hand, to so limit the range of a transmitter that broadcasting were even contemplated, the aim in view there is little choice given to the listener beyond his in the design. of all aerials for transmitting stations was own local station, is a disadvantage which many of our undoubtedly to obtain the greatest possible range. With readers might consider would offset the admitted gain aerials of simple type some attention was later paid to in other directions. It would seem that some alterna- their shape and dimensions, with the object of en- tive solution to ether congestion could be found which deavouring to conserve the energy so that it was prin- would not deprive us of the opportunity of listel.ing to cipally radiated in one direction. the programmes of our neighbours, and we shall hope Short wavelengths were found to be particularly to refer to this matter again in the near future. B 9

,_- www.americanradiohistory.com II_; Wpdago JANUARY 3oth, 1929. MAC

Consideration of Loud Speaker Windings for Optimum Performance. By N. W. McLACHLAN, D.Sc., M.I.E.E., F.Inst.P.

IN the first article ' on the above subject it was possible to work the valves biased to the approximate shown that there were two salient methods of using mid -points of the linear portions of their characteristics. push -pull amplification so far as grid bias was con - This is the safer procedure when the valve character- cerned. One method was to bias the valves to the istics are unknown. Even here it is better to middle of the curved portions ; the other, to bias to pair the valves by ascertaining their characteristics. the middle of the straight portions of their character- In this article I propose to istics. Both methods have limitations where the valve treat the mid -point method characteristics are appreciably different, but less latitude of biasing only. Before em- can, in general, be allowed where the bias is fixed on barking upon the main the curved portion. For example, assume we have theme of the article it will two valves whose linear portions are of different slopes be well to get a clear con- (inclination to the horizontal axis). Then each extremity ception of the physical dif- of the complete push -pull characteristic will have the ferences between the two But, same slopes as the respective valve characteristic. methods of biasing. The GRID BIA6 since the slopes are different, the combined character- original push -pull idea em- GRID VOLTS istic will not be a single straight line. Thus distortion bodied two valves, back to will ensue. back, each dealing with one - Fig . 2 . - Shaded portion In using the latter method of biasing, it is desirable half of the incoming wave. shows field of activity of V, of Fig. i when V2 is in opera- to obtain the valve curves and determine the proper The valves are stated in tion. Valves are biased to mid -points of curved por- value of grid bias for a particular pair of valves. It patent specification 275 / 15 tions of characteristics. to operate unidirectionally. Moreover, to simulate this condition, the grid bias must be fixed substantially near the rectification point. This immediately determines that the middle of the curved portion is the proper place. Of course, there is a certain amount of action of the valve V, of Fig. i in a negative direction, this being indicated by the shaded portion in Fig. z but it is substantially negligible. In a practical sense, therefore, V, deals with the positive half of the wave, and V, with the negative half. Each valve performs only one operation, i.e., metaphorically speaking it either pushes or it pulls, but it does not

push and pull. . In other words, V, is active, whilst V, Fig. 1. -A simple push -pull arrangement. Observe that the currents are flowing in V1 and V2 in opposite directions. The mag- is dormant and vice versa. netic effects, however, are clearly additive, i.e., V, pulls and V2 pushes. Biasing to Mid -point of Straight Portion. bias to the middle of the straight por- may easily happen that where an experimenter buys Now when we tions of the valve characteristics, the physical action is couple of valves at random, this mode of push -pull a quite different. Under this condition both valves, Vi, working will be out of the question. Moreover, it is V,, of Fig. r, deal with the positive and the negative ' June 13th, 1928. halves of the wave. The wave under consideration is [The present article was prepared some months before those viewed from the anode side of the valve preceding the on the pentode by the same author, which appeared in July, 1928. Publication has been held back to allow for other articles of power stage. It so happens that, with respect to the immediate interest by Dr. McLachlan. -ED.] negative pole of the filament, the grid of V, is relatively B IO

www.americanradiohistory.com JANUARY 3oth, 1929. Winhgv MAO 115 The Theory of Push -Pull. at the other attribute to the problem, namely, quality. positive, whilst that of Va is negative, but that is merely Here again the strictly scientific aspect of the subject due to the transformer secondary being split and virtu- imposes peculiarities at various frequencies which baffle ally converting the positive half of the wave into two us in obtaining a straightforward solution. If, however, parts equal numerically. In a system where the we agree to work with a certain deg-3e of current varia- valves are placed back to back throughout, as shown tion over part of the frequency range, the problem at in Fig. 3, each valve in the amplifier deals with both once becomes soluble. I have found in practice that, halves of the wave. Whether the scheme of Fig. I or so far as moving -coil loud speakers are concerned, this of Fig. 3 is employed, the voltage applied to the grid is a reliable mode of attacking the problem. Referring of V, is always 18o° out of phase (anti-phase) with that to Fig. 4 (a), it is clear that, so far as alternating current applied to V1. Similarly, the voltage changes at the anodes of the two valves are 18o° out of phase. Since each of the valves V1,. V_, of Fig. 1, deals with both halves of the wave, we immediately ask, " Is this push - pull amplification? " If we interpret push -pull as explained above, where each valve performs on alternate half waves only, then biasing to the middle points of L. 5. the linear characteristics must be regarded as a different thing. In the latter arrangement we have virtually two amplifying systems in parallel, but i8o° out of phase. Moreover, it would not be inappropriate to (a.) (b) describe this method of amplification as the ' ` parallel anti -phase," abbreviated p -a-p, as against the other Fig. 4. -A simple power valve circuit with lout speaker is shown method of p -p. in (a). The choke and the condenser cause the A.C. to pass through the loud speaker, but to avoid the battery. In (b) the Matching of Power Valve and Loud Speaker. equivalent circuit of Fig. i is shown as a first approximation. To get a proper perspective of the problem of load is concerned, the power valve circuit can be represented impedance associated with the power valve, it is well by Fig. 4 (b). Since in a moving -coil loud speaker (or to begin with the usual simple circuit shown in any other loud speaker in varying degree) the moving Fig. 4 (a). The loud speaker is so arranged that the armature or coil generates a back E.M.F. due to its anode feed current does its not pass through winding, motion in the magnetic field, the diagram of Fig. 4 (b) and the usual associated filter circuit is connected to requires modification to take this into account. In The reduce the A.C. through the H.T. supply to a very Wireless World, March 3oth, 1927,, I gave the equi- small amount, thereby eliminating feed -back effects. valent . coil -drive speaker, for high- and for Now we know for circuit of a that maximum output the impedance resistance the latter being associated with a of the loud low- coils, speaker must bear a certain relationship to transformer. It was shown that at any particular fre- that of the power valve. Since the impedance of a the coil from its usual static A.C. in- loud speaker varies with the frequency of the luency -apart current ductance and resistance-in motion was equivalent to a condenser in series with a resistance. The resistance is such that resistance x (current)2 = power radiated as sound. The circuit for a high -resistance coil without output transformer is shown in Fig. 5 (a). So far as the resistance (termed the radiation resistance) is concerned, its magnitude is too small to affect the value of the current in the coil to any extent that is appreciable. There are three audio -frequency ranges to be considered : (I) low, (2) medium, (3) high. At low frequencies the coil impedance 2 is due mainly to its motion in the magnetic field. It is then equivalent to a condenser whose value in microfarads is Effective mass of diaphragm and coil x Io'S

Fig. 3.,-Diagram of amplifier in which each stage is arrange I C'n [Length of wire on coil x strength of magnetic field] 2 with valves back to back and biased to the mid -points of their linear characteristics. XIot3 in its winding, how is the desired relationship to be In a typical case at low frequencies, computed? The matching of loud speaker and valve m=25 grams (this includes accession to inertia due cannot be effective at more than one frequency, so we to air moved 3), have the unsatisfactory answer that it can't be done. Having got into this difficulty, we must find some 2 Assuming the resonance due to the diaphragm support to be below audibility. loophole of escape. We cannot solve our " quantity " ' See The Wireless World, March 30th, 1927, or " Loud or optimum intensity problem ; let us look, therefore, Speakers," by this author. B I'

www.americanradiohistory.com i? aä -aia-GG`:i.,._-? PRIM!"?1e :; - s } tl=V _i .41rS+F,, (M, 1" 04A.,. ` -.

r r6 WATsigeo JANUARY 3oth, 1929. Wait].

The Theory of Push -Pull. With a triode 5 this would result in a somewhat puny C= írdnH, where d =dia. of moving coil in cm. output from the loud speaker, owing to the small n =turns on moving coil. current change. It is possible, of course, to reduce H = strength of field.4 the loud-speaker reactance by decreasing the number = rX5XiO3X7XI03 of turns, but here again the output suffers. Moreover, = 3.57r x107 some compromise must be made, and, judging from Thus C2=1.25 x io16 results, the power valve resistance can be taken as Hence the equivalent capacity in microfarads is about 3,0Oó ohms. IOln 25 X Although the current at the upper audio frequencies C _ =2.o mfd. 1.25 x 1016 decreases appreciably due to inductive reactance and At 32 cycles the impedance of this condenser is enhanced resistance, the output is not correspondingly 1 106 _ 2,50o ohms. 2irfCm - 2rrx32x2 R1= RESISTANCE B1 In case (2) for middle frequencies neither the condenser nor the inductance of the coil offers serious im- w J U G$- pedance. In fact, one counteracts the other, and there < '-°P I- 11 is an electromechanical resonance frequency at which U J 0e w 3 the current is found from the formula I = V / R1. Here ¢ R1 in Fig. 5 (b) is the A.C. resistance of the coil plus O RI= RESISTANCE the internal resistance of the power valve. For the 1,000-turn coil assumed above, the A.C. resistance at (a) (b) Soo cycles would be about I,000 ohms. Fig. 6.- 14ector diagrams giving, method of obtaining impedance of loud speaker circuit. (a) is for frequencies above resonance, The Concertina Effect. (b) for frequencies below resonance. For the high -frequency register (case 3) we have to consider mainly the reactive impedance. The induct- diminished. This effect is due to a high -frequency ance of coil résonance associated with the junction of cone and coil. the at 4,00o cycles is about 0.1 henry, and ` the corresponding reactance is 2,50o ohms. Thus we The ' neck " or connection between the two acts like a have at each end of the acoustic register 32 to 4,000 spring, so that there is a " concertina effect. "6 cycles, a coil reactance of 2,50o ohms in addition to Furthermore, this is accentuated if the cone is made of stiff paper. When using a pentode the current will be relatively greater at the extremities of the acoustic c c, register than with a triode. Moreover, when used with a cone having prominent " neck " and " surround " resonances in the audio -frequency register, the results are likely to be disconcerting. Judging from accounts, I fear that a few experimenters have been hit by this misfortune. Rni M Optimum Results from Two Valves in Push -pull. (a) (b) The combined impedance of loud speaker and power valve is obtained from the vector diagrams of Fig. 6. The reactive component in each case is drawn at 9o° Fig. 5. -The true equivalent circuit of Fig i is shown in (a). P is to the resistive component, since the respective voltages the A.C. valve resistance; C, the by -pass condenser; L, the inductance of moving coil (at rest); R, the A.C. resistance of the are in quadrature (phase displacement of 90 electrical moving coil; R,,,, the radiation resistance due to sound energy degrees). OC1 is emitted ; C,,,, the motional capacity due to motion of coil in mag- The numerical value of 4,700 ohms netic field, and V the voltage of the fictitious alternator. Diagram and of OC 5,70o ohms. In the latter case the resistive (b) is the equivalent circuit of Fig. 3 at resonance when the inductive and compacitive impedances are equal. component is increased, due to the eddy current and hysteresis loss in the iron of the electromagnet. The the A.C. resistance. For constant current over this D.C. resistance of the coil is about 930 ohms, but its frequency range, the impedance of the power valve A.C. resistance at 4,000 cycles is 2,200 ohms. Thus circuit of Fig. 4 (a) must be constant. This means the influence of the extra resistance due to iron loss is that the internal resistance of the power valve should to augment the total circuit impedance at 4,000 cycles, be large enough to swamp the reactance of 2,500 ohms. so that the current falls away as the frequency rises. An actual current- frequency curve for equal voltages 4 In the loud speaker design (see The Wireless World, April on the grid of the power valve is shown in Fig. 7. 1927) a rather was 13th, large allowance mide in the magnet The net result of the preceding investigation is that winding to prevent overheating. A stronger magnetic field can be obtained if a pot wound for 160 to 180 volts is used on we have jockeyed ourselves on certain grounds, to the 200 volts, or one for 200 volts is used on 240 volts. The pot will get warm, but a dull black coating will help heat dissipation. 5 See The Wireless World, July 11th, 18th, 25th, 1928, also The increased output is an advantage of this arrangement, later in the present article. which in the hands of a competent amateur is quite safe. See The Wireless World, October 17th, 1928. B I2

www.americanradiohistory.com JANUARY 3oth, 1929. WAp@Il®@0 Ilj WWIld The Theory of Push -Pull. valve in parallel on each side. This will give a voltage position of a moving coil having i,000 turns of wire 2v, and a valve resistance of 3,000 ohms, the coil being on a former tin. in diameter (5 cm.), this being operated as before. But since the voltage has been doubled and by a power valve whose internal resistance should -for the impedance of the valve circuit unaltered, the power good quality -not be less than 3,000 ohms. output is quadrupled (four times). The next step is to extend the above analysis from Now the reader will say : Yes. That is all very well, the single stage power valve to the push-pull arrange- but I cannot afford to use four power valves. With this ment. The governing condition is that we shall on all I entirely agree, so we must endeavour to ascertain occasions have a circuit which gives acoustic quality whether two valves back to back can be used to better equivalent to a tin. coil of i,000 turns operated by a advantage. The total valve resistance is 6,000 ohms, power valve of 3,000 ohms internal resistance. The arrangement to be treated is that where the power valves are biased to the mid -points of the straight portions of their characteristics. A circuit arrangement is shown in Fig. 8(a) suitable for a high- resistance coil. Both valves are always operative and conductive. If the voltage change at the anode of Vt at any instant is +v1, that on V2 is - vl, hence the total A.C. voltage round the circuit is 2v. The A.C. impedance of the circuit is the vector sum of the coil impedance and twice the A.C. valve resistance. The equivalent arrangement of the circuit is shown in Fig. 8(b). Here we have a generator of voltage 2V in series with the internal resistance, etc., of both valves and the coil. Taking approximate figures, for equal grid volts,' the value Fig. 8.- Simple push -pull circuit (a) with two power valves an a centre-tapped output choke. In (h) tha equivalent circuit of 5(b) of the current in Fig. 8(b) is equal to that of the is given. See Fig. 3 for meaning of symbols. 2v is the voltage of simple circuit of Fig. 4(a) (neglecting coil impedance). the fictitious alternator whica represents the next change in anode voltage of V,, V2 of Fig. 5 (b). Thus with the same coil in both cases the output from the -pull push circuit is little better than that of the so that we can raise the coil impedance to match. The ordinary circuit. But since the valve resistance is coil impedance depends upon the the number doubled, square of the coil impedance is relatively smaller, so that of turns, i.e., if the inductance of 1,000 turns at 4,000 cycles is 0.1 henry, that of 2,000 turns is 0.4 henry. ' Since we have doubled the valve ,resistance, we must double the coil impedance to secure the constant quality 30 MMEttAMM/MEMMOMOMMEMMEMMEMsi\OMMEMUMMEMME and conform to our above condition. Clearly the coil MOMMMOOMMEMMOMOMMIUMMEMMEMMOMEMOMMEMEMME MMMMMes0111111MMEME:ITIMMMOMMEMEMrEMMEMMEMUOMMts:=NMONOIMMMICOMMOMU turns must be multiplied by N/2- 1.414. Thus our coil MO5IMIMMEM MMMMMMM! OMMnOMOMMEMMEMMOsMMEMMIl.aaMMIN,t.MOIMMEMMEM will have approximately 1,40o turns. For a given MEMMOMMEM M/M\M MEMMMEMEM\V\MMMO/OMMEMM current8 the power output is proportional to the square iiiQiiiiiiiiiiiiiiiiiiiiiíiiiiiiiiiii 20 MMEMMOMMEMMOMMOSOMMMEMMEMOMEMMWOMMEMOM of the turns on the coil. Moreover., by using a coil of. MOMMIIIMMEMMOMMEMOMME MIIMMEMMINIMM MM MM MEM EMMOMOMMOMMEMEMOOMMOMMEMMEMIUMMEMMcSOMM 1,400 turns in the push -pull circuit, the acoustic power MOMMOMYMMEMINIMMIMMEMMOMMOMMMOMOMMMEMEM MMINIMMOIMMIIMMEMESMEMMOMEMEMMOMOMMINIMMIIM/ output is doubled. In practice the augmented acoustic MMOM1OYMMINIMEMMMOMOMMEMEMOMMEMOMOMM\IMOM MMOMMOOMMMEMOMOMMINIMMUMIl energy would not appear aurally to be considerable, MMIMMEMEMEMMOMIMEMOMMEMMEMOMMOISMOMMMINIMMEMMEMMO MUMMEMrOMMOINIMMEMEMME MOMOMMEMOMMIOMMOMMOMMOMOMMOMMEMMEMMEMMEM but it would be comfortably noticeable on loud inten- 10 MMEMEMOMMIMMEMMOMMEMOMsMMMMMMMMMMMMMMMMM MMEMMEMMEMMEMOMOMMIMMUMMEMMOMMMOMMEMOMME sities. This is due to the fact that the aural apprecia- MIIMMOMMOMMOMMMOMMOOMIIMOMMIIMMOEMEMMMEMOMMMMMMOMMINI tion of acoustic intensities follows substantially a logar- MOMMMEMMONIUMMEMMINIMEMMOMMOMMOMMOMEMMOM ithmic law. MOMMOMMOMMOMMOMMIMMEMMEMEMEMMOMMOMMtMOO MMEMEMEMOMMOMOMMEMMUMMOMOOMMEMEMOMMEMMO Moreover, to, make any real difference, the output iiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii should be quadrupled. This can be done as shown 32 64 128 256 512 1024 2048 4096 8192 above, with four power valves ; alternatively, it can be FREQUENCY N CYCLES PER SECOND accomplished with two valves by increasing the H.T. and grid bias 1/ 2 times. The reader should test this Fig. 7.- Diagram showing variation in coil current of loud speaker aspect of acoustic appreciation for himself. There are with frequency. The current falls away as the frequency rases due to the inductance of the winding. One LS5A valve was used. various ways of doing it. One is to tap down the grid leak a known amount and then by a switch go back the current is reduced less at high and at low frequen- quickly to the original setting. Another method is to cies. Moreover, the quality is better, although in prac- insert a resistance of any convenient value in series tice it might not appear to be altered appreciably. with the loud speaker and short circuit it (the resistance). Obviously, to get our standard condition of coil and If the resistance is equal to that of coil plus power valve, valve (1,000 turns and 3,000 ohms), we must add a the power output can be approximately reduced to one

To secure this the swing on 'V, and on V, must equal that a The current is the same as for the simple circuit, since both on the valve in Fig. 4. volts and impedance are doubled. B 53

www.americanradiohistory.com t4 ® r, .. e;$', i-.:" R , i$' 0.s= '417!

178 WflTig11®00 JANUARY 3oth, 7929.

The Theory of Push -Pull. Let us assume the pentode to have an internal resist- quarter (the output is proportional to the square of the ance of 30,000 ohms10, then the quality will be identical coil current) as depicted in Fig. 9. with the former case if the number of turns is increased The preceding argument is based upon the assumption to I,000 x / 30,000 3,100, sa The desired that the power valves are triodes. Since the article was 3,000 - Y, 3.000. written the pentode has number of turns can be accommodated if 48 enamelled popped up. The theory, is 0 wire used. Fo'r reasons given previously" the number however, is by no means of turns has been limited to 2. oo. Compared with a invalid, but merely requires saZo 3,000 -ohm triode LS5A and i,000 -turn coil, the power extension. As I showed in N

More Peace on Higher Wavelengths. We understand that negotiations are Now that the Washington regulations in progress for the compilation of a joint have come into force considerable inter- TRANSMITTERS' NOTES. international call book by the present ference is being experienced by amateurs American publishers and the Radio working on the 7=500 kc. (40 metres) Society of Great Britain. band. It has been found that of the old method a station being received very 0000 three amateur short -wave bands, powerfully would be given a strength of The New Intermediates. 30,000 kc. (10 metres), 14,284 kc. (21 R8 or R9. The modern equivalent of metres), and 7,143 kc. (42 metres), the The new nationality prefixes are being this is QSA5, while a strength of R3 is conscientiously adopted by the majority latter is the most reliable channel for now termed QSA2, or thereabouts. long-distance working. The natural noon of transmitters. The prefixes of the result is that considerable interference is principal countries are as follows :- caused, especially at night, by the Skip Distance Effects. America W, Austria U0, Belgium ON, united efforts of the world's amateurs to Mr. John H. Hopkins (G2ASA), of France F, Germany D, Great Britain G, occupy a small frequency range. Kildare, Wii scombe, Somerset, wishes Finland OH, Denmark OZ, Spain We would suggest, however, that more to arrange tests with other amateurs, pre- EE -EAR, Sweden SM, Switzerland HB, attention be devoted to the 1,970 to ferably in connection with skip effects Portugal CT, Poland SP, New Zealand and cloud absorption. ZL, Canada VE, Australia 1,740 kc. (152.2 to 172.2 metres) band. 0000 and Tas- Long- distance C.W. communication is mania VK, Irish Free State EI. easily effected on this batid, and while German Amateur Seeks Tests. 0 0 0 0 the range of a transmitter is somewhat Tests with British amateurs using Dirty Weather Ahead? limited when working on the longer 'phone or C.W. on the 42 -metre band are We understand that although an un- amateur band, this disadvantage is being sought by Radio D(ek)-4SM, an ruffled calm of acquiescence with the new balanced by the comparative freedom experimenter in the Saarbrücken district. order of things is being maintained in from fading and interference. He is using low power, but hopes that most countries, storms are brewing in someone in England has heard him. o o ^. o Belgium. A well -known Belgian amateur Reports should be addressed c/o DFTV, informs us that certain transmitters in The New Telegraphic Abbreviations. Blumenthralstrasse 19, Berlin W57, or his country have approached the Govern- Some confusion still exists with regard c/o BRS90, 34, \Vest Street, Stalybridge. ment and obtained leave to maintain the to the new radio telegraphic abbrevia- 0000 old EB prefix. This is asking for con- tions. A number of stations are observ- Call Signs of the World. fusion. ing the original meanings of the " Q " Readers who have experienced diffi- The Belgians complain that French code, with the consequence that when culty in obtaining copies of the Radio stations are " spoiling the game " with they are in communication with stations Amateur Call Book, published in New raw notes, but it seems to us that, if any using the new code a rather unhappy York, will be glad to learn that copies old call letters are to be used, it hardly state of affairs is occasionally brought can now be obtained direct from the matters much what sort of note goes out, about. English representative, Mr. F. T. Carter, provided that it is illegible. If the Bel- The modified " Q " code should, of Flat A, Gleneagle Mansions, Streatham, gians wish to stick to obsolete prefixes course, be used without exception. London, S.W. The price per copy is the sooner they use bad notes the better. The revised signal strength scale is 4s. 6d. The Call Book is a quarterly However, certain Belgian amateurs have deserving of a little more attention. The publication, not semi -annual as stated in signified their intention to adhere to the abbreviation QSA must precede the our issue of January 2nd. The next new regulations. More strength to their signal strength number (1 to 5). By the issue will appear in March. signals! B 14

www.americanradiohistory.com JANUARY 3oth, 1929. WATe®00 119 WopIlCI nPy Talks fo Ab itYork

Australia's Latest Short =wave Feat. By A CORRESPONDENT. T seems to have escaped general notice in this coun- Within a few minutes the station was heard on the desk try that on November 1st Australia and the United telephone, and a representative of the Sydney Morning States made a noteworthy contribution to the history Herald conversed with officials at Java for more than of short-wave communication by achieving two-way half an hour. wireless telephony of a commercially useful standard The pièce de résistance, however, was the telephonic between Sydney and Schenectady-a distance of io,000 communication with New York. Shortly before ro miles -and between Sydney and Java. The occasion p.m. it was announced that the line was clear to the was a Press demonstration of the new equipment evolved G.E.C. station at Schenectady, New York. Mr. Fisk by Amalgamated Wireless (Australasia), Ltd., under the spoke for a few minutes and then introduced Mr. Law - managing directorship of Mr. E. T. Fisk, who has ton, Consul -General of .America, who exchanged greet- organised a scheme of centralisation whereby practically ings with Mr. Dow, Secretary of the Australian Commis- all the wireless stations of New South Wales are concen- sioner's office in New York. Then followed what might trated on two sites under the direction of a central con- be termed a general conversation between the New York trol office. On one of these sites -Pennant Hills-is and Sydney pressmen. That the test was, in every way, the transmitting centre, with the 20 kW. telephony plant an undoubted success was partly due to the General Elec- used in the Sydney- Schenectady experiment. The other tric Company of America and also to the Dutch East site is on the coast at La Perouse, and here the Indies Radio Company, who willingly consented to co- receiving centre for the New York telephony is in- operate with the A.W.A. stalled. The station is shown in our title illustration. Successful telephony tests were again carried out on The control centre is at the headquarters of Amal- Monday night, November 5th, between Amalgamated gamated Wireless, 47, York Street, Sydney. Wireless headquarters, Sydney and Schenectady, New York, the voices from the U.S.A. coming through with Calling Java and New York. great clarity. The demonstration test with New York was scheduled The Australian Station. for ro p.m. on the evening of November 1st, but earlier Station 2ME at Pennant Hills, some 14 miles from in the day the Press representatives were taken over the Sydney, operates on a wavelength of 28.5 metres. The transmitting and receiving centres to give them an ade- equipment, specially designed by A.W.A. engineers, was quate conception of the methods employed. When the manufactured at the company's " Radio -Electric party returned to headquarters, Mr. Fisk, seated at his Works," Sydney. office desk, telephoned instructions to La Perouse to get The new 20 kW. short -wave transmitter is of the very in touch with Bandoeng, Java, over 2,000 miles away. latest design, and it is of interest to note that the main u 15

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I20 WApigIlMg Td7VTTdT?V oní.b rnon pIlc`1 Sydney Talks to New York. - cuits is obtained from a low -power modulator and amplifier bank employ rectifier of approximately 3 kW. the latest valves in which the anodes The wave range of the transmitter are cooled by means of oil circulating is from 15 to 5o metres, and the ap- through specially constructed jackets. paratus can be used for telegraph sig- The transmitter itself consists of nals up to 30o words per minute. seven main units :- The aerial, which is of the vertical I. Drive and No. 2 Magnifier type, is about 400ft. from the trans- (I kW. each). mitter, and is fed by means of lecher 2. No. I Magnifier (3 kW.). wires. 3. Power Magnifier (2o kW.). The Pennant Hills station has done 4. Keying Unit (2o kW.). some praiseworthy work in the de- 5. Modulator Unit (25 kW.). velopment of Empire broadcasting, 6. Large Rectifier. and it is specially disappointing that 7. Small Rectifier. the test relay of New Year greet- The filaments of the valves in the ings to British listeners, which had first 5 units are heated from two 140 - been arranged for December 31st, was amp. 25 -volt D.C. generators, with not fulfilled owing to dislocation the exception of the drive and sub - caused by fire at Bailan. modulator valves, which are heated The receiving centre at La Perouse from a 500- ampere -hour battery. is to -day the largest and most modem The filaments of the rectifying station of its kind in the Southern valves are heated by current of I2!, Hemisphere. During the last eighteen volts, 5o cycles, stepped down from months the station has become famous 240 volts. for several feats of reception. One of Power for the anodes of the valves particular interest to Australians was in the transmitter circuit proper is the reception and relaying of messages obtained from a 3o kW. rectifier from the " Southern Cross " plane on unit comprising six large glass recti- its Pacific flight. Another triumph of 2ME, SYDNEY. The 400ft. mast of fying valves and appropriate smooth- Australia's best - known short - wave which the engineers at La Perouse are transmitter, situated at Pennant Hills, ing circuits composed of inductances near Sydney. Besides establishing tele- justly proud is the reception of mess- phonic communication with New York, and condensers, whilst power for the ages from Australian ships in . this 20 kw. station has provided relays lying anodes of the drive and buffer cir- for British listeners. Tilbury Docks.

A USEFUL 1lLA A . CHAR (NaOo (J1) Ratio of H.F. Resistance to D.C. Resistance of a Coil.

THIS ratio may be written as Single -layer Coil. Skin Factor + g3 [Litz number + A] L =self-inductance= 20o microhenrys. or Skin Factor + Proximity Factor. f =1 megacycle. Where the skin factor and g depend only on frequency N = number of turns = 43.5 and diameter of wire or strand, the Litz number depends D = diameter of coil in inches = 4in. only on the particular used, Litz and A depends on the d = diameter of each strand in inches = o. 00421ín. shape and diameter of the coil, number of turns, and n = number of strands = 27. kind of Litz used. l = length of coil = 2in. It was pointed out in connection with Abac 20 that, when the correct gauge of wire is used to give The Skin Factor. minimum decrement, the skin factor is approximately equal to the proximity factor, so that it is unnecessary Inset 1 shows that a line dust be drawn through the to ascertain the latter. This rule, however, does not values of f and d and on the return journey a tangent is always give sufficiently accurate results, and in any drawn to the curve : the skin factor is found to be case the nearest available gauge of wire may differ con- 1.009. siderably from the gauge calculated, so that it is sometimes necessary to calculate both skin factor and prox- The Value of g. imity factor. To illustrate the working of Abac 21 we Inset 2 shows that a line must be drawn through the shall take the following example, referring to a coil values f and cl and on the return journey a tangent is wound with stranded wire, the best diameter of strand drawn to the g curve : the value of g is found to be having been found from Abac 1g. 0.294. B 16

www.americanradiohistory.com JANUARY 30th, 1929. Wpshoo,s- Op. 121

C 6,000 5.000 0'03 = 4.000

3,000 004 2.000 = 005

006 J 1,000 Ó 800 O =0'07 0.01 3= LL L-0.08 600 O 0.8 - 0'09 ó00 cc 04 06 É-0 1 400 0.02 î 05 300 0'5 2- 0-4 0'03 G ZQ 0.3 200 06 =- 015 004 1'5 w 4 0'05 0'7 2 0.2 5 VALUES YD 006 O OF 0.8 6 -0.2 100 - 0'1 0.08 O 005 09 i-Z 8 80 01 1 Z 0.1 0-2 09= 10 60 Ñ 0-08 50 0.8 LL MANY LAYER 03 SOLENOID 03 O 0'06 40 0' 0.4 0.2 SK Np ¢ -I 0.05 20 1.5 30 0.6= R IW- f 0'04 0'3 30 h Wq 0 20 cc -j osi O n Z 40 05 0.8 A c}i 0.5 0'02 50 08 z < rc .4=, 60 O 0 O i 1-0 10 W O W a î08 ÓÑ w < cc 80 SINGLE LAYER 8 u) SOLENOID ? 1 3 4 g 0.3_ 001 100 i 0'8 6 Y Z c x - ou) O O'008 =0'9 5 O Y ¢ Z W 4 N D. Q ¢ O'006 4 g- CURVE al 2 N., î 3 0005 200 ¢ 5 O 02 LL 0004 ó u. I- u. 3 300 S ' O 0003 w 1.5 4 6 0 01'5 = 400 m W 5 7 w 2 2 0002 500 _a 6 600 8 Z p OLL 8 g 800 0'8 O 0 1 = 10 , 0 001 1,000 10 i 0.09- 06 cc 0.08 05 Ó 0'4 007- N 20 2.000 0'3 15 0-06= 30 3.000 02 0'05 = 40 20 = 4.000 50 004 5,000 60 -.al. 6.000 0'1 80 8,000 0.08 100 30 0-03= 101)00 =- 8 PIVOT 0.08 9 0'05 40 -10 0'04 200 0.03 002= BELATIVE D.C. BESISTANCE 4 4 T o02

RATIO OF H.F. RESISTANCE TO D.C. RESISTANCE OF A COIL 0'01 SKIN FACTOR + Q3(LIT2 NUMBER + A) SKIN FACTOR + PROXIMITY FACTOR