m ~-v\_ r ■ i .. *
■■ A 1 j? TH E NATIONAL g V RADIO 1 EXHIBITION OLYMPIA SEPT I8to26 I S3 I e Histone v/d Radic f The best in Radio NEW SETS. 3 Valve Screened Grid Band Pass 4 „ »> »» »> »» 5 „ Super Het. Transportable Table Models Consolettes Radiograms Biograms All Mains 3-Valve Screened Grid Band Pass Table Model, Cat. No. 457 etc. £19 19 O New Components. Permanent Magnet Moving Coil Speaker Carbon Microphone Sets and Components at Condenser Microphone THE NATIONAL RADIO EXHIBITION, 1931. Pick-ups and Arms Resistances STAND No. 41 DEMONSTRATION ROOM D25 Pre Set Condensers EDISON BELL, LIMITED, etc. LONDON S.E.15 Edison Bell Condensers—Best for all purposes. it BIBLIOTHEEK n.v.h. r, ACCUMULATORS for ii thighs tension D© not mm the ingenious Dagenite <'C!%ggt§gg: TeH Tale" : tv. device on i i- 7 y. ' ( STAND 15 \ \! •; ?> MAIN HALL THE NATIONAL ACCUMULATOR COMPANY LIMITED L 93 GT. PORTLAND STREET, LONDON, W.l ! D.4 t 1 \ WIRELESS BATTERY SURPRISES EXPERT 66Almost unbelievable results ” AN EXTRAORDINARY CONTRAST The writer of the following letter resolved to make a scientific test. He bought two H.T. batteries of different makes Here, in his own words, is the remarkable result. " Dear Sirs: You may be interested in an experiment I am at present making, the details of which l will supply you with from time to time. In March last, I built Mr. James' magnificent set, the ‘ Super 60,’ and I had a doubt as to what batteries to use. I finally decided on a 60 volt EVER READY and a 60 volt------my intention being to test them and then carry on with the best make. Day by day I have religiously carried out the tests, each day changing the batteries so that one took the full load every other day: (this in my opinion being the only method of testing accurately). The enclosed graph will show you the almost unbelievable results obtained so far. I am wondering if you have accidentally stored a mains unit in this battery ! The graph of the other battery 1 dare not send as it may get me into trouble with the makers. Sufficient to state that the EVER READY is worth well over double the price." Leonard Foley, Manchester. (this letter may be inspected at the office of the Company). This unsolicited testimonial confirms what the EVER READY Company has been telling the wireless public for years—that for elimination of distortion, for un wavering power and for long life, an EVER READY battery is better than any other battery on the market. I This is no accident, but the result of the exclusive process by which every EVER READY battery is made. There is an EVER READY battery to power every kind and size of set, portables included. Write for free list to the address below. We are exhibiting a‘ »he National THE EVER READY CO. GT. BRITAIN) LTD. HER Radio Exhibition CULES PLACE, HOLLO Stand No. Jt WAY. LONDON. N.7. 2 JBIBLIOTHEEK n.v.h.r. £KSy r- mrL ORGANISED BY THS PADIO MANUFACTURERS ASSOCIATION ASTQR HOUSE-ALOWYCH- LONOON WC 2 11 $ m •I g v mm ■mpmw n mi W is/official ...CATALOGUEIS jMff/ OFTHE ® NATIONAL RADIO % f ^EXHIBITION .• m) m V % w l-mm l OLYMPIA imt® wM to 2 6 :• 1931 3 f A •ijjJ STAND 26 ------NATIONAL HALL------DEMONSTRATION ROOM D4. /' ■ -EKC@- Famous as Pioneers and Leading Specialists in British All Electric Radio, present an ■ m. entirely new range of Radio- ; Grams, Consoles, Consolettes and Power Units. <- o- -o- New and exclusive features— Utmost simplicity and reliability— Extremely reasonable prices. ■o -o <- E. K. COLE, Ltd,, Dept. O.C., EKCO Works, Southend-on-Sea. I woburk JBIBLIOTHEEK N.V.H.R* CONTENTS. PAGE Official Appointments ...... 7 Plan of Stands on Ground Floor ...... 8-9 National Hall ... 8 Empire Hall ...... 9 Plan of Stands and Demonstration Rooms on First Floor 10-11 National Hall (Demonstration Rooms) ...... 10 Empire Hall (Stands)...... 11 Index to Exhibitors ...... 13-15 Index to Telephone Numbers of Stands ...... 17 A Message from Lt.-Col. J. T. C. Moore-Brabazon, M.C., President of The Radio Manufacturers’ Association... 19 To Our Visitors—Mr. R. Milward Ellis, Chairman of The Radio Manufacturers’ Association and Chairman of the Exhibition’s Com mittee 21 A Message from the B.B.C.—Sir John Reith...... 23 Broadcasting Stations : Their Characteristics and Times of Transmission...... 24-31 British Stations ...... 24 European Stations ...... 25-29 Short Wave Stations...... 30-31 General Notices ...... 39 Particulars of Exhibits ...... 41-199 Stands on the Ground Floor : National Hall (Stands 1 to 47) ... 41-115 Empire Hall (Stands 51 to 108) ...... 117-159 Loudspeaker Supply Arrangements and Special B.B.C. Exhibit 160-161 Stands and Demonstration Rooms on First Floor : Empire Hall (Stands 151 to 256)...... 163-194 National Hall (Demonstration Rooms) ...... 194-199 List of Members of The Radio Manufacturers’ Association ... 200-202 Classified Directory of Exhibits ...... 203-209 Index to Advertisers ...... - ...... 211 N.B._The greatest care has been taken in the compilation of this Catalogue, but the Organisers do not accept any responsibility for alterations, omissions or errors. 5 ! i i For daily last-minute information in foreign programmes .... for latest news of develop ments in wireless .... for expert answers to every-day radio queries—see The Daily Maily Britain’s great National Newspaper, which gives fullest attention to Britain’s most popular pastime. Because of its supreme pulling-power, leading radio manufacturers and dealers consistently use The Daily Mail as the basis of their selling campaigns. Reaching every town and village throughout Great Britain, it provides, in itself, a complete advertising campaign in the United Kingdom. DAILY MAIL 6 BIBLIOTHEEK •M.v.n.n* OFFICIAL APPOINTMENTS Press Agent: Mr. GARRY ALLIGHAN, Excel House, Whitcomb Street, W.C.2. (’Phone : Regent 7687 & Gerrard 3388.) Advertising Agents: MATHER & CROWTHER, LTD., New Bridge Street, E.C.4. Stand Fitters & Decorators: GROUND FLOOR STANDS F. STRUTT, Albion Works, Albion Street, Caledonian Road, N.l. DANCE FLOOR, DEMONSTRATION ROOMS AND STANDS ON FIRST FLOOR OLYMPIA, LTD., Kensington, London, W.14. Sign Writing: A. PERTON, 3, Beaconsfield Terrace Road, W:l4. Florists : STROUD BROS., LTD., 182, Green Lanes, Finsbury Park, N.4. Caterers : J. LYONS & CO., LTD., Cadby Hall, London, W.14. Stand Cleaners: GENERAL WINDOW CLEANING CO., 6, Avery Row, Bond Street, W.l. Lighting Installation: BROOKS & WHITE, Electrical Engineers, 10, Maclise Road, London, W.14. The Organisers are indebted to The Edison Swan Electric Co. Ltd., for advice and assistance given by their illumination engineers in connection with the Lighting Installation. i MUSIC i The Music throughout the Exhibition and on the Dance Floor will be produced by electrical reproduction from broadcasting or from gramophone records supplied by The Columbia Graphophone Co. Ltd. and The Gramophone Co. Ltd. PATENTS, TRADE MARKS AND DESIGNS. [NOTE : Inventors and others wishing to PROTECT INVENTIONS, REGISTER TRADE MARKS and DESIGNS (British and Foreign), or desirous of advice generally on Patents and similar matters, may refer their enquiries to Gee dc Co., Patent Agents and Trade Mark Agents (H. T. P. Gee, Patent and Trade Mark Agent, Great Britain; U.S.A. and Canadian Rcgd. Patent and Trade Mark Attorney ; Mem. Australian Inst, of Patent Attorneys; Member Radio Society of Great Britain; Assoc. Mem. Inst. Radio Engs., CO O CO i 0£ •t I r \ O CM in !o * B CM o M* I -I i ; u. 4 '■ i i t i >r o 2 CM I r> i<7> i D i ! r 1 CM o I I _J X a i i -I i O o CO i < ro :co in 4 i An Index to Exhibitors appears on pages 13 & 15. For Plan of Stands and Demonstration Rooms on First Floor see pages 10 6? 11. A numerical list of Stands and Demonstration Rooms with particulars of Exhibits will be found on pages 41 to 199. A Classified Directory of Exhibits is included on pages 203 to 209. 8 aIaU t *=I S’ . t 2 3 -J >< SI Hi ¥ z. HI ■cm CM .• CO % UM [I] CO r*. >£> cxi m o r*. 5 t- (\J x o UJ CO cX lO o CO ex cx -I Si CM §9 -J 11 in < § T CO m CD I o in m UJ n H a. 1 a z UJ IX 00 $ (X in a § .rm 5 cO CO I <0 0) 00 IN o |N O CM co cx O CD C0 fM ex in CD CD * CO IX in O oO m Wr~* — o fM I Will SN0A1 t t 2 2 An Index to Exhibitors appears on pages 13 6? 15. For Plan of Stands and Demonstration Rooms on First Floor see pages 10 & 11. A numerical list of Stands and Demonstration Rooms with particulars of Exhibits will be found on pages 41 to 199. A Classified Directory of Exhibits is included on pages 203 to 209 9 □ CO o 6 o N £2 a o Q Q o h % X <3- i UJ Q S ! a m =m= Q or CD CD O d o 1 C\J < o ii Q N O i ■ C^i < Q Q h- _1 < CL dOOU OMOOdO ou U t V) ! o < -J I u 4= a x a r o a BONnoi *" a 3D Nn o~] ft a IS An Index to Exhibitors appears on pages 13 & 15. For Plan of Stands on Ground Floor see pages 8 & 9. A numerical list of Stands and Demonstration Rooms with particulars of Exhibits will be found on pages 41 to 199. A Classified Directory of Exhibits is included on pages 203 to 209. 10 L -OO sn f o to Q < I- co u_ o < CL DC o o _l Ll H (0 DC U. • • < X ID DC 0. 2 ID An Index to- Exhibitors appears on pages 13 fi? 15. For Plan of Stands on Ground Floor see pages 8 6? 9. A numerical list of Stands and Demonstration Rooms with particulars of Exhibits will be found on pages 41 to 199, A Classified Directory of Exhibits is included on pages 203 to 209. 11 f You must^m m •'.v Ii$t I fete m K mmm$ mi&W; SUN v CK tipi® Bp •$»ip sffigfe STAND jsi«fe* * No. mitml ifeIP a s pfiI® 203 SlM SUNCO ■ %•Ii SI tew SERVICE * ■ *m sREAL is r IBlllilig ||i SERVI gpp |KBl» m> / §ipg§ , K m g&* 12 t. INDEX TO EXHIBITORS. GROUND FLOOR: NATIONAL HALL. (Stands 1 to 47) STAND NO. STAND NO. Belling & Lee, Ltd. ... 13 London Electric Wire Co. & Smiths, Ltd. 27 British General Manufacturing Co., Ltd. 30 Lotus Radio, Ltd. 23 Brown, Ltd., S. G...... 2 j McMichael, Ltd., L. Brownie Wireless Co. of G. B., Ltd. 37 5 Bullphone, Ltd...... ) Marconiphone Co., Ltd...... 4 12 Montague Radio Inventions & Develo Burton, C. F. & H...... 31 ment Co., Ltd. 47 Celestion, Ltd...... 40 Mullard Wireless Service Co., Ltd. 18 Chloride Electrical Storage Co., Ltd. 8 National Accumulator Co., Ltd. 15 Clarke & Co. (M/c.), Ltd., H. ... 33 New London Electron Works, Ltd. Climax Radio Electric, Ltd. 42 35 Cole, Ltd., E. K...... 26 Ormond Engineering Co., Ltd. ... 34 Columbia Graphophone Co., Ltd. 7 Partridge Wilson & Co. ... 43 Colvem, Ltd...... 38 Pertrix, Ltd. 39 Cossor, Ltd., A. C...... 16 Pye Radio, Ltd. ... 9 Dibben & Sons, Ltd., Wm. 1 Radio Gramophone Development C Edison Bell, Ltd. ... 41 Ltd...... 11 Edison Swan Electric Co., Ltd. ... 21 Radio Instruments, Ltd. 29 Electrical & Radio Products (1931). Lk 3 Ready Radio, Ltd. 6 Regentone, Ltd...... 22 Ferranti, Ltd...... 45 Fuller Accumulator Co. (1926), Ltd. ... 36 Six-Sixty Radio Co., Ltd. 20 Telegraph Condenser Co., Ltd. ... 14 General Electric Co., Ltd. 24 Telsen Electric Co., Ltd. 19 Graham-Farish, Ltd. 32 Ultra Electric, Ltd. 10 Igranic Electric Co., Ltd. 28 Westingliouse Brake & Saxby Signal Co Kolster-Brandes, Ltd. 25 Ltd...... 44 Lissen, Ltd. 17 Whiteley Electrical Radio Co., Ltd. 46 GROUND FLOOR: EMPIRE HALL, (Stands 51 to 108) STAND NO. STAND NO. Amalgamated Press, Ltd. ... 67 Iliffe & Sons, Ltd...... 57 Benjamin Electric, Ltd...... 99 Jackson Bros., Ltd. ... 62 Bernard Jones Publications, Ltd 71 Junit Mfg. Co., Ltd. ... 97 British Blue Spot Co., Ltd. 65 L.E.S. Distributors, Ltd. ... SS Brown Brothers, Ltd...... 105 Magnavox (Great Britain), Ltd. ... 10S Bulgin & Co., Ltd., A. F. ... 102 Mains Radio Gramophones, Ltd. ... 53 C. A. V. Batteries, Ltd...... 91 Murphy Radio, Ltd...... 59 Carrington Manufacturing Co., Ltd. ... 51 Oldham & Son, Ltd. ... 66 Danipad Rubber Co., Ltd. ... 70 Oliver Pell Control, Ltd. (Varley) 5S Darwins, Ltd...... 101 Osram Valves (G.E.C.) ...... 77 Dew & Co., Ltd., A. J. ... 104 Portadyne Radio ...... 103 Downing & Sons, Ltd., John S. 54 Priestly & Ford ...... 69 Dubilier Condenser Co. (1925), Ltd. 92 “ Radio for the Million ” ... SO Dyson & Co. (Works), Ltd., J...... 78 Rolls Caydon, Ltd...... 56 Eddystone Radio Products ... 9S Rooke Brothers, Ltd. ... 79 Electric Gramophones, Ltd. 89 Selectors (1931), Ltd...... 83 Ensign, Ltd. (Houghton’s) 85 Siemens Electric Lamps & Supplies, Ltd. 74 Epoch Radio Mfg. Co., Ltd. ... 106 Simpsons Electricals Ltd. ... 93 Ever Ready Co. (G. B.), Ltd...... 76 Smurthwaite, F. W...... 107 Sovereign Products, Ltd. 64 Falk Stadelmann & Co., Ltd...... S7 94 ... 61 Standard Battery Co...... Formo Co...... Stratton & Co., Ltd...... 9S General Electric Co., Ltd. (Osram Swift Levick & Sons, Ltd. ... 52 Valves)...... 77 Tannoy Products...... 63 Graham Amplion, Ltd...... 75 Turner & Co...... S2 Gripso Co...... 81 Urnello, Ltd...... 73 Grosvenor Electric Batteries, Ltd. ... 72 Watmel Wireless Co., Ltd. .X 100 Hacker & Sons, H...... 95 Whittingham Smith & Co. 103 Halcyon Wireless Co., Ltd. 96 Wilkins & Wright, Ltd...... 90 Harlie Bros. (Edmonton), Ltd. ... 84 Wingrove & Rogers, Ltd. 60 Heayberd & Co., F. C...... 6S “ Wireless & Gramophone Trader ” 55 Hustler Simpson & Webb, Ltd. ... 86 “Wireless World” ... 57 13 (Continued on page 15) ATTERIES 1932 BUDGET REDUCED PRICES ; LARGER RANGE and IMPROVED DESIGN Call at STAND No. 91 14 INDEX TO EXHIBITORS—continued. FIRST FLOOR: EMPIRE HALL. (Stands 151 to 256) STAND NO. STAND NO. Adie & Co.. Ltd...... 169 Homo Electric, Ltd. ... 214 Arding & Hobbs, Ltd. 171 Hunt, Ltd., A. H. .. 232 Atalanta ...... 191 Hunton, Ltd. .. 233 Audiovisor, Ltd...... 226 Itonia Gramophones, Ltd. .. 167 Automatic Coil Winder & Electrical Equipment Co., Ltd...... 207 Jewel Pen Co., Ltd. .. 156 Auto Electric Devices, Ltd. ... 159 Johnson Talking Machine Co., Ltd. .. 180 B. & S. Electrical Co., Ltd. ... 181 Kalisky (Aldgate), Ltd., S. .. 151 Baird Television, Ltd. 157 Lamplugh, Ltd., S. A. .. 168 Bakers Selhurst Radio ... 216 Lectro-Linx, Ltd. .. 202 Beaver Electrical Supply Co. 165 Lithanode Co., Ltd. .. 249 Betta Electric Motors, Ltd. 21S Lock, Ltd., W. & T. .. 160 Bird & Sons, Ltd., Sydney S. .. 172 Mains Power Radio Co...... 229 Birkby’s, Ltd...... 206 Manufacturers’ Accessories Co. (192S), British Broadcasting Corporation 211 Ltd...... 1S6 British Ebonite Co., Ltd. 153 Mellor, G...... 255 British Hard Rubber Co., Ltd. .. 182 Mullard Wireless Service Co., Ltd. .. 221 British Radiophone, Ltd. ... 155 British Rola Co., Ltd. ... 250 Osborn, Charles A. .. 205 British “ Wireless for the Blind ” Fund 254 Overseas Trading Corporation ... .. 173 Broadcaster & Wireless Retailer ... 154 P. R. Products .. 187 Brooks, Ltd., Kenneth...... 225 Park Royal Engineering Co., Ltd. .. 194 Cadiscli & Sons, R. ... 1S4 Paroussi, E. .. 15S Calders Ltd...... 183 Partridge & Mee, Ltd. .. 177 Catesbys, Ltd. 245 Pegasus, Ltd...... 238 Churchmans, Ltd. 200 Peto Scott Co., Ltd. .. 179 Colassion, Ltd. ... 209 Pioneer Mfg. Co., Ltd. .. 1S8 Concordia Electric Wire Co., Ltd. ... 248 Primus Mfg. Co., Ltd...... 193 Craufurd Wireless...... 242 Pritchard & Simpson, Ltd. .. 243 Crypto Electrical Co., Ltd. ... 235 R.C. Radio Electric, Ltd. .. 237 Dayzite, Ltd. ... 251 “ Radio for the Million ” .. 199 De la Rue & Co.. Ltd., Thos...... 164 Radio Service (London), Ltd...... 162 Department of Overseas Trade ...... 253 Radio Society of Gt. Britain .. 246 Donotone (Regd.) Loud Speaker 161 Redfern’s Rubber Works, Ltd. .. 163 Dulcetto-Polyphon, Ltd. ... 230 Rees Mace Mfg. Co., Ltd. .. 215 Rolls Radio, Ltd__ East London Rubber Co., Ltd...... 176 .. 256 Eastick & Sons, J. J. ... 252 Sel-Ezi Wireless Supply Co., Ltd. .. 190 Econasign C'o.. Ltd. ... 241 Selfridge & Co., Ltd. .. 234 Electrical Devices Co. ... 185 Shapland & Petter, Ltd. .. 217 Electro Dynamic Construction Co., Ltd. 228 Slektun Products...... 208 Ericsson Telephones, Ltd. ... 219 Speakeasie Home Recorders, Ltd. .. 236 ... 192 Sun Electrical Co., Ltd. .. 203 Faudels, Ltd. Swain, Ltd., Charles ...... 244 Fay Home Recorders, Ltd. 220 Synchrophone, Ltd...... Flinders (Wholesale), Ltd. 204 .. 223 Fullotone Gramophones (1929), Ltd. ... 201 Taylor, Ltd., Henry E...... 212 Telsen Electric Co., Ltd. Gamage, Ltd., A. W. ... 195 .. 213 178 Thompson Diamond & Butcher .. 210 Garrard Engg. & Mfg. Co., Ltd. Tonex Co...... 231 Garratt Stores 240 Trade Chronicles, Ltd...... 247 Goodmans... 239 Graham & Co., R. F. 189 Valunda Switches .. 224 Greatrex & Co., R. G. 197 Voltron Electric, Ltd. .. 227 Gutta Pcreha Co...... 196 Whiteley, Ltd., William...... 198 Henderson Wireless & Electrical Service 170 Wireless Retailers’ Association, of G.B 174 Hillman Brothers, Ltd...... 166 Wright & Weaire, Ltd...... 152 Hobday Bros., Ltd. ... 175 Yagerphone, Ltd...... 222 FIRST FLOOR: NATIONAL HALL. Demonstration Rooms. ROOM NO. BOOM NO. Bakers Selhurst Radio...... D 23 Lissen, Ltd...... D 6 British Blue Spot Co., Ltd...... D 22 Lotus Radio, Ltd...... D 1 British Rola Co., Ltd...... D10 McMichael, Ltd., L...... D 14 Celestion, Ltd...... D 9 Marconiphone Co., Ltd. ... D3&D24 Cole, Ltd., E. K. D 4 Oliver Pell Control, Ltd. (Varley) ... D 21 Columbia Graphophone Co., Ltd. D 2 Radio Gramophone Development Co., Edison Bell, Ltd...... D 25 Ltd...... D 16 Fay Home Recorders, Ltd. ... D 7 Ready Radio, Ltd. Dll General Electric Co., Ltd. D 8 Speakeasie Home Recorders, Ltd. ... D 17 Kolster-Brandes, Ltd. D 5 Synchrophone, Ltd. ... . D 16 Lamplugh, Ltd., S. A. D 20 Ultra Electric, Ltd. D IS—19 16 The Wireless AND RADIO REVIEWWorld The Complete Wireless Journal—covers every phase of radio—provides the expert knowledge and the practical information which enables its readers to get better EVERY reception. WEDNESDAY “ THE WIRELESS WORLD ” should be read by everyone who takes an interest in the develop 4d. ment and progress of wireless. It is the most From all Neivsagents reliable exponent of wireless theory and practice. and Bookstalls The prevailing tendencies are discussed week by week and descriptions of new and thoroughly tested receivers, embodying the newest notions WlreJSss? for securing both selectivity and quality, are published at frequent intervals. Regular weekly features include reports of labora tory tests of new apparatus, answers to readers’ pa problems, notes and news Make sure of your copies and practical hints and tips. w.. of “ THE WIRELESS WORLD ” Special Show The regular reader is kept sapi Numbers, and enter for in close touch with all “THE WIRELESS WORLD” that happens in radio SUBSCRIPTIONS circles everywhere. Home & Canada OLYMPIA SHOW £1 U. 8d. ILIFFE & SONS LTD. Other Countries Abroad COMPETITION £1 3j. 10 ILIFFE & SONS LTD., DORSET HOUSE, TUDOR STREET, LONDON, E.C.4 16 TELEPHONE NUMBERS OF STANDS, Etc. shephiskd’s bush shepherd’s bush Adie & Co., Ltd...... 1929 L.b.S. Distributors, Ltd...... 4540 Amalgamated Press, Ltd...... 1465 Lock, W. & T., Ltd...... 4791 Aiding & Hobbs, Ltd...... 2150 London Electric Wire Co. & Smiths, Automatic Coil Winder & Electrical Ltd...... 3865 Equipment Co., Ltd., The ...... 4027 Lotus Radio, Ltd. ... 3755 B.B.C., The ...... 3679 Mains Power Radio Co., The ...... 2955 Belling & Lee, Ltd...... 503S Marconiphone Co., Ltd. .. 2453 & 2547 Benjamin Electric, Ltd., The...... 1835 McMichael, L., Ltd...... 4733 Bird, Sydney S., & Sons, Ltd. ... 3952 Montague Radio Inventions & Develop British Blue Spot Co., Ltd...... 2721 ment Co., Ltd. ... 1955 British Ebonite Co., Ltd., The ... 2137 Milliard Wireless Service Co., Ltd.,The 4936 British General Mfg. Co., Ltd. ... 5037 Murphy Radio, Ltd...... 2749 British Radio Valve Manufacturers’ National Accumulator Co., Ltd. ... 2147 Association ...... 3763 New London Electron Works, Ltd. ... 3937 “ Broadcaster ” ... 4129 Brooks & White ... 2647 Odhams Press, Ltd. ... 4129 Brown Bros., Ltd. ... 2637 Oldham & Son, Ltd...... 4745 Brownie Wireless Co. of G.B., Ltd. ... 5243 Ormond Engineering Co., Ltd., The ... 3235 Overseas Trading Corporation ... 2551 Cadisch, R., & Sons ... 2716 Partridge & Mee, Ltd__ ... 2455 Catesbys, Ltd...... 1531 Pertrix, Ltd. ... 1829 Celestion, Ltd. ... 2554 Portadyne Radio ... 4876 Chloride Electrical Storage Co., Ltd 1949 Press Bureau (Radio Manufacturers’ Clarke, H., & Co. (Manchester), Ltd 2636 Association) ...... 1048/9 Climax Radio Electric, Ltd. ... 4873 Pye Radio, Ltd. ... 3653 Cole, E. K., Ltd. 4157 Columbia Graphoplione Co., Ltd. ... 1164/5 Radio Gramophone Development Co., Cossor, A. C., Ltd. ... 3953 Ltd...... 5138 Radio Instruments, Ltd. ... 5059 Darwins, Ltd...... 3852 Radio Manufacturers’ Association Dayzite, Ltd. ... 3651 (Press Bureau) ...1048/9 Dew, A. J., & Co., Ltd. 3547 Radio Manufacturers’ Association Dubilier Condenser Co. (1925), Ltd. 2951 (Secretarial Offices). Dulcetto Polyphon, Ltd. 2445 National Hall ... 4338 & 1535 Dyson, J., & Co. (Works), Ltd. ... 152S Empire Hall, Ground Floor ... 4476 East London Rubber Co. ... 5236 Empiro Hall, First Floor... 1837 Edison Bell, Ltd. 3557 Ready Radio, Ltd...... 4856 Edison Swan Electric Co., Ltd., The. 2961 Rees Mace Mfg. Co., Ltd. ... 3245 Eddystone Radio ... 1331 Regentone, Ltd...... 4249 Electrical Devices Co...... 4257 Secretarial Offices, See Radio Manufac Electrical & Radio Products (1931), turers’ Association. Ltd...... 3758 Selfridge & Co., Ltd...... 3237 Ensign, Ltd. (Houghtons) ... 1458 Shapland & Petter, Ltd. ... 2843 ... 4165 Siemens Electric Lamps & Supplies, “ Fay ” Home Recorders, Ltd. Ltd...... 2825 Ferranti, Ltd...... 5133 2962 ... 3851 Simpsons Electricals, Ltd. Flinders (Wholesale), Ltd. Six-Sixty Radio Co., Ltd. 4019 Garaage, A. W., Ltd...... 4939 Standard Battery Co. ... 1825 Garrard Engineering & Manufacturing Stratton & Co., Ltd. ... 1331 Co., Ltd., The ...... 3229 Sun Electrical Co., Ltd. 2731 General Electric Co., Ltd., The 1529 Swift, Levick & Sons, Ltd. ... 175S General Electric Co., Ltd., The 4256 Telegraph Condenser Co., Ltd., The... 5145 Graham Amplion, Ltd. . 1339 Telsen Electric Co., Ltd. ... 4951 Grosvenor Electric Batteries, Ltd. ... 4933 . Thompson, Diamond & Butcher ... 4038 Trader Publishing Co., Ltd...... 6233 Halcyon Wireless Co., Ltd...... 1765 Heayberd, F. C., & Co. 3360 Ultra Electric, Ltd...... 1334 Hillman Bros...... 1335 4729 Vandervell, C. A., & Co., Ltd. ... 5132 Hobday Brothers, Ltd. Varley (Oliver Pell Control, Ltd.) ... 3553 Hustler, Simpson & Webb, Ltd. ... 1769 Westinghouse Brake & Saxby Signal Igranic Electric Co., Ltd. ... 3757 ... 2823 Co., Ltd...... 1763 Iliffe & Sons, Ltd...... Whiteley Electrical Radio Co., Ltd. 2835 Jackson Brothers ...... 2653 Whiteloy, William, Ltd. 5071 Johnson Talking Machine Co., Ltd., Whittingham, Smith & Co. 4876 The ...... 4850 Wingrove & Rogers, Ltd. 5237 Hjalisky, S. (Aldgate), Ltd...... 2543 “ Wireless & Gramophone Trader ” 6233 Kolster-Brandes. Ltd__ ... 1475 “ Wireless World ” ...... 2823 17 B B m- RADIO OF THE At & IS: m i. .* i if mHr FUTURE-NOW ifi B m •• !?'F;i 4 m ALL - MAINS, : : SELF - CONTAINED, *ar. :r MAGNAVOX MOVING COIL SPEAKER, c ■ MAZDA VALVES, IRRESISTIBLE EASY PAYMENT TERMS. This remarkable LOTUS Table Console sets a new standard in radio receivers. Combining all the superlative features luawiui s enumerated above and enclosed in a luxurious walnut finished cabinet of 3 VALVE matchless proportions, it is a marvel y\j_L" [S S of va,ue* TABLE CONSOLE for A.C. or D.C. Mains. One knob tuning makes operation as r | Hire Purchase Terms : — simple as it can possibly be. exclusive 27/9 down and 11 monthly payments of 27/9 each. dual-wave binocular coils ensure Hair- CASH PRICE Line Selectivity. Truly the Radio of the Future—NOW ! £14.14.0 ✓ N, There is a re Lotus Compo markable range nents include SEE Condensers, of new Lotus Components. Slow Motion Theyare miracles STAND No. Drives, Coils, of design, finish T ransfor mers, and efficiency, Chokes, Jacks, and are low in Switches, Valve price. Holders, etc. ■s 23 l ILiQi/W'UI S i MILL LANE, LIVERPOOL. LOTUS RADIO LTD • i 18 A Message from Lt.-Col. J. T. C. Moore-Brabazon, M.C. UN D AMENTA L, research in ][ the laboratory discovered the corpuscular nature of electricity. Clark Maxwell laid down the laws that govern electro-magnetism before his work could be of value. Slowly but surely science, from discovering an interesting laboratory pheno menon, has presented us with one of the most potent forces in the world to-day. We find in this Exhibition the expression of this work, and an exhibition to the public of the fruits of great endeavours. The radio industry is still young, but the English products are acknow ledged as being in the van of the world. The Exhibition you are visiting will show you the very latest things that this new craft can produce. We are asked to encourage new industries in this country ; here is one that deserves all our support, not only from the national point of view, but also from a purely selfish point of view, because investment .up to the limit of our means in the best apparatus that we can buy will give a return of amusement and pleasure lasting the whole year that justifies almost extravagance. If our industry is to lead the world, it can only do so if it gets whole-hearted support from the public. This message is to you visiting this Exhibition from whatever point of view you are interested in the subject, whether as a scientist, as a builder of sets from component parts, or as one who only wishes to hear well and be entertained. Never mind how it is. You have come in to view our products. Help us by buying to the utmost of your means. r* £ - )■ I President of The Radio Manufacturers Association. 10 i PYE QUALITY constitutes the highest standard of achievement in radio. In technique, i craftsmanship, presenta 1 i tion and reliability, ( Pye have always been i predominant. I i 1 BRITISH AND BEST-----MADE IN CAMBRIDGE : Pye Radio Ltd., Sales Organisation, Paris House, Oxford Circus, London, IV.J. 20 I To Our Visitors. T is given to few people to make an exhibition of themselves and feel I proud of it. The Radio Manu facturers' Association occupies this unusual position to-day. The National Radio Exhibition, which you now have an opportunity of viewing, is organised by the R.M.A., and is comprised of pro ducts made almost entirely by members of the Association. In this sense we make an exhibition of ourselves. And we feel sure you will agree we have every reason to feel proud of it. The membership of the Association is formed entirely of British radio manu facturers. The Exhibition is devoted entirely to British radio productions. We believe at the present time that nothing is more important to the continued pros perity of this country than the develop ment of British industry. We feel sure that every visitor to this Exhibition will give preference to British radio products. Mr. R. Milward Ellis. We are convinced that the future pros perity of this country lies in the develop ment of new British industries to replace those which changing conditions through out the world have rendered of less importance. Radio is a new British industry. The future progress of British radio depends only on the support of the British listener. In this great Radio Exhibition, the largest ever held, you will find every desire of the listener has been anticipated and met. Not only has technical progress in design more than kept pace with every development in broadcasting, but the very urgent need for finer apparatus at far less expenditure has dominated designs throughout the Exhibition. Never before has it been possible to offer such highly technical and complex receivers, combined with such extreme simplicity of opera tion and control, at prices which must appeal irresistibly to every listener. Ask yourself a question. In comparison with everything else on which you spend your money, what is radio worth to you ? Radio is the least expensive form of entertainment and yet the most comprehensive. It comprises music, drama, news, topical events, education, variety, dancing, popular talks, ethics, religion—in a word, it is a system of national culture—it offers you a complete new life to fill your idle moments. And it throws in the correct time, S.O.S. messages, birthday greetings to the children and many other things besides. All this it brings to your fireside and charges nothing extra for additional listeners. Radio is worth ten times what it costs. And more : properly used, it is a very definite economy. Ladies and Gentlemen, listeners all, on behalf of the Radio Manufacturers’ Association, welcome! Chairman, R.M.A. Chairman, Exhibition's Committee. 21 IU S. ELECTRICAL CO. LIMITED. City Depot: Showrooms: 9, BRUNSWICK PLACE, 24, SACKVILLE STREET, CITY ROAD, N.l. PICCADILLY, W.1. We are displaying:— Superheterodyne Receivers 7-Valve All Mains Chassis 7'Valve “ Midget,” “ Console ” and “ Radiograms ” 5-Valve Superhet Portables and Table Models 5-Valve Superhet Portable Suitcases 2 and 3-Valve All Mains Receivers 2-Valve All Mains Radiograms 4-Valve Screen Grid Portables 5-Valve Receivers Suitcase Portable Gramophone and Pickups Loud Speakers and Assorted Components Call and see as at our Stand 181 1st FLOOR. EMPIRE HALL. S • 22 j4 Message from the B.B.C to the ZNjational f^adio Exhibition. ^ ^ ^ HE continued progress Tof the British Radio Industry, as exemplified year by year in bigger and more successful National Exhibitions, is " in parallel with ” unceasing development and expansion of the broad casting service. Since your last Exhibition the new high power transmitters for the North of England have been established, and, thanks in no small measure to the active co-operation of the radio industry, with the minimum Sir J. C. W. Re.th of inconvenience to the listening public. Broadcasting House will soon be ready, and greatly improved studio arrangements will be reflected in the quality of the transmissions. On behalf of the British Broadcasting Corporation I offer the heartiest good wishes to The Radio Manufacturers’ Association for the unexampled success of the 1931 Exhibition. » u ✓r 23 BROADCASTING STATIONS I Their Characteristics and Times of Transmission. I BRITISH STATIONS. Frequen Approximate Times of Power, cies in Wave Transmission. Station. (in kws.) kilo- length (Hague cycles per j (in Rating.) second. metres). Sundays.Weekdays. i 10.15 to 11. 0 10.30 to 10.45 Daventry National 35 193 1554.4 12. 0 to 2.30 3. 0 to 6.15 4. 0 to 12. 0 8. 0 to 10.45 3.30 to 5.15 Midland Regional 38 752 398.9 ' /12. 0 to 3. 0 V 5.15 to 11. 0 8. 0 to 10.45 3. 0 to 6.15 London National 68 1148 261.3 12. 0 to 2.30 { 5.15 to 11. 0 8. 0 to 10.45 10.15 to 11. 0 3.30 to 5.15 i London Regional 70 842 356.3 12. 0 to 3. 0 8. 0 to 10.45 ‘ 4. 0 to 12. 0 North National 70 995 301.5 /12. Oto 2.30 3. 0 to 6.15 \ 5.15 to 11. 0 8. 0 to 10.45 fl0.15toll. 0 3.30 to 5.15 North Regional 70 626 ! 479.2 12. Oto 3. 0 8. 0 to 10.45 t 4. 0 to 12. 0 Aberdeen 1.2 1040 288.5 ( 10.15 to 11. 0 3. 0 to 6.15 l 4. Oto 11. 0 8. 0 to 10.45 Belfast 1.2 1238 242.3 10.15 to 11. 0 3. 0 to 6.15 { 4. 0 to 11. 0 8. 0 to 10.45 Bournemouth 1.2 1040 288.5 fl0.15toll. 0 3. 0 to 6.15 . \ 4. 0 to 11. 0 8. 0 to 10.45 Cardiff 1.2 968 I 309.9 10.15 to 11. 0 3. 0 to 6.15 | { 4. 0 to 11. 0 8. 0 to 10.45 Glasgow 1.2 797 376.4 10.15 to 11. 0 3. 0 to 6.15 { 4. 0 to 11. 0 8. 0 to 10.45 Newcastle 10.15 to 11. 0 3. 0 to 6.15 1.2 1040 288.5 { 4. 0 to 11. 0 8. 0 to 10.45 Dundee 10.15 to 11. 0 3. 0 to 6.15 .16 1040 288.5 K 4. Oto 11. 0 8. 0 to 10.45 Edinburgh ... 10.15 to 11. 0 3. 0 to 6.15 .4 1040 288.5 { 4. Oto 11. 0 8. 0 to 10.45 !/10.15 to 11. 0 3. 0 to 6.15 Hull*... .16 1040 288.5 \ 4. Oto 11. 0 8. 0 to 10.45 10.15 to 11. 0 3. 0 to 6.15 Liverpool* ... .16 1040 288.5 { 4. Oto 11. 0 8. 0 to 10.45 10.15 to 11. 0 3. 0 to 6.15 Plymouth .16 1040 288.5 { 4. 0 to 11. 0 8. 0 to 10.45 10.15 to 11. 0 3. Oto 6.15 Sheffield* .16 1040 288.5 { 4. 0 to 11. 0 8. 0 to 10.45 10.15 to 11. 0 3. Oto 6.15 Stoke-on-Trent* .16 1040 288.5 4. 0 to 11. 0 8. 0 to 10.45 i { 10.15 to 11. 0 3. 0 to 6.15 Swansea .16 1040 288.5 { 4. 0 to 11. 0 8. 0 to 10.45 * Suspended. Note : The Hat has been compiled with tlie assistance of the British Broadcasting Corporation. The times of transmission given above are intended as a general guide only and must not be taken to imply that the stations give continuous broadcast between the hours stated. 24 ■ BROADCASTING STATIONS—continued. EUROPEAN STATIONS. (In decreasing order of Wave-length.) Fre quency Wave- Power Hours of Transmission. Station in Kilo- length in j and cycles in Kilo- I Country. per Metres, watts, Weekdays. Sundays. second.' Ankara 195 1938 70 5 p.m. to 7.0 p.m. 5 p.m. to 7.0 p.m. Turkey Kovno 155 1935 7-0 12 noon to 10 p.m. 5 p.m. to 10 p.m. Lithuania Hilversum 160 1875 8-5 7.40 a.m. to 11.40 p.m. (approx.)j 8.10 a.m. to 11.40 Holland p.m. (approx.) Lahti ... 167 1796 54-0 11 a.m. to 10 p.m. ! 8.15 a.m. to 10 p.m. Finland Paris (Radio- 174 1725 170 6.45 a.m. to 10 p.m. j 7.45 a.m. to llip.m. Paris, CFR) i (approx.). France Berlin (Konigs 183.5 1635 75-0 5.45 a.m. to 12.30 a.m. except 6.30 a.m. to 12.30 wusterhausen) Tuesdays, when station closes j a.m. Germany at 12 midnight (approx.) Moscow (Old 202.5 1481 400 10 a.m. to 10.30 p.m. 10 a.m. to 10.30 Komintern) p.m. Russia Paris (Eiffel 207 1445.7 15-0 6.45 p.m. to 10 p.m. 6.45 p.m. to 10 p.m. Towor FL) France Warsaw 212.5 1411 1580 11.40 a.m. to 12 midnight 10.15 a.m. to Poland 12 midnight. Motala... 222.5 1348 400 See Stockholm (436 m.) Sweden Moscow (Trades 230.6 1304 75-0 4 a.m. to 8 p.m. 4 a.m. to 8 p.m. Union WZSPS) Russia Boden ...... 250 1200 0*75 See Stockholm (436 m.) Sweden Stamboul 250 1200 5-0 Temporarily closed down. Turkey Kalundborg ... 260 1153 100 7.30 a.m. to 12.15 a.m. 8.30 a.m. to Denmark 12.30 a.m. Oslo ...... 277 1083 75-0 11.5 a.m. to between 10 and 11 10.50 a.m. to Norway p.m. 12 midnight Wednes 12 midnight. days and Saturdays. Ostersund 389 770 0-75 See Stockholm (436 m.) Sweden Geneva 395 760 1-5 See Radio-Suisse Romande Switzerland (403 m.) Moscow (Ex 416.6 720 20*0 1 p.m. to 9.55 p.m. 1 p.m. to 9.55 p.m. perimental) U.d.S.S.R. Lausanne 442 680 0*6 See Radio-Suisse Romande Switzerland (403 m.) Hamar...... 511 587.1 0*8 See Oslo (1083 m.) Norway Ljubljana 522 574.7 2-8 12.15 p.m. to 10.45 p.m. (approx.)i 9 a.m. to 11 p.m. Jugoslavia 1 (approx.) • Freiburg 527 569 0-3 See Miihlacker (360 m.). Germany Hanover 530 566 0*3 See Hamburg (372 m.). Germany Augsburg 536 560 0-3 See Munich (533 m.). Kaiserslautern Germany Budapest 545 550 23’0 9.15 a.m. to 10.30 or 10 p.m. 9 a.m. to about I Hungary 10 or 11 p.m. Sundsvall 554 15-0542 See Stockholm (436 m.). I Sweden i : Palermo 554 541-5 4-0 12.45 p.m. to 12 midnight j 10.50 a.m. to 12 Italy (approx.).______1 midnight. 26 BROADCASTING STATIONS—continued. EUROPEAN STATIONS. (In decreasing order of Wave-length.) ■ I'To- ! quency Wave- Power Hours of Transmission. I Station in Kilo length in i and cycles in i Kilo- Country. ' per Metres. watts. Weekdays. Sundays. second. 1 Munich 563 533 1-7 6.45 a.m. to 10.30 p.m. or 12 10 a.m. to 12 mid ! Germany midnight night. Riga ... 572 524 130 11 a.m. to 11 p.m. 9 a.m. to 11 p.m. Latvia Vienna... 581 516-3 20 0 9.20 a.m. to 10.30 p.m. or 10 or 10.30 a.m. to Austria 11.30 p.m. 10.45 p.m. (approx.). Brussels No. 1... 590 508-5 20-0 5 p.m. to 10.15 p.m. 5 p.m. to 10.15 p.m. Belgium Milan ... 599 500.8 8-5 8.15 a.m. Closes down between 10 a.m. to 12 Italy 11 p.m. and 12 midnight. midnight. Prague 617 487 5-5 11.30a.m. to 11.15 p.m. (approx.) 7 a.m. to 11 p.m. Czecho slovakia Langenberg ... 635 473 17-0 6.45 a.m. to 10.15 p.m. or mid 7 a.m. to midnight. Germany night. Saturdays 1 a.m. (Sun.). Schweizerischer 653 459 77 12.30 p.m. to 10.15 p.m. Sats : 9.55 a.m. (approx.) Landessender Midnight. to 10.45 p.m. f Beromunster, Switzerland. Bodo, Norway 662 453-2 0-6 See Oslo (1,083 m.). Klagenfurt 662 453.2 0-6 Relays Vienna. News daily at Austria 8 p.m. Mons. Thurs., Kris., Sats., at noon. Sats. 10.45 a.m. Trondheim 662 453-1 1-13 See Oslo (1,083 m.). Norway Bolzano 662 453 0-2 12.30 p.m. to 10.45 p.m. 10.30 a.m. to Italy 10.45 p.m. Porsgrund 662 453 1-5 See Oslo (1,083 m.). Norway Paris (Ecole 671 447.1 1-0 8 a.m. to 11 p.m. (approx.). 8 a.m. to 12 mid SupSrieure) night. France Notodden 671 447.1 0-9 See Oslo (1,083 m.). Rjukan Norway Rome 680 441 750 8.15 a.m. to 11 p.m. 10 a.m. to 11 p.m. Italy Stockholm 689 436 75-0 8 a.m. to between 11 p.m. and 11 a.m. to 11 p.m. Sweden midnight. Belgrade 695.5 431 3-0 11.35 a.m. to between 10.30 and 11a.m. to 11.30p.m. Jugoslavia 11.30 p.m. Madrid 707 424 2-0 9 a.m. to 1.30 a.m. Mondays 9 a.m. to 1.30 a.m. Spain 12.45 p.m. to 1.30 a.m. Berlin (Witzle- 716 418 1*7 6-30 a.m. to 12.30 a.m. except 6.30 a.m. to ben) Mondays and Tuesdays, when 12.30 a.m. Germany station closes at 11.15 p.m. and 10.30 p.m. respectively. Rabat...... 721 416 2-5 1.30 p.m. to 11 p.m. (approx.). 1 p.m. to 11 p m. Morocco Dublin 725 413 1.5 I. 30 p.m. to 10.45 p.m. 8.30 a.m. to Ireland 11.15 p.m. Katowice 734 408-7 16-0 II. 40 a.m. to 11.30 p.m. 9 a.m. to 12 p.m. Poland (approx.)., Radio-Suisse 743 403 32 12.28 p.m. to between 10.45 p.m. 10.45 a.m. to 10.30 Romande and 11 p.m. p.m. (approx.). (Sottens) Switzerland Bucharest 761 394 16 2.15 p.m. to 8.40 p.m. (approx.). 8.25 a.m. to 8.45 Roumania Saturdays 2.15 p.m. to 9.40 p.m. p.m. 26 BROADCASTING STATIONS—continued. EUROPEAN STATIONS. (In decreasing order of Wave-length.) ' | Fre quency Wave- ; Power. Hours of Transmission. Station in Kilo- length; I in and cycles in Kilo- Country. per Metres. watts. Weekdays. Sundays. second.' Frankfurt 770 389-6 1-7 5.55 a.m. to between 11.30 and 7 a.m. to 12.30 a.m. Germany 12.30 a.m., usually midnight. Closes down earlier on Weds. (10.30 p.m. to 11 p.m.) Usually relays dance music late on Sats. and Suns. Toulouse (Radio - 779 385 8-0 12.45 p.m. to 12.15 a.m. 12.30 p.m. to phonie du 12.15 a.m. Midi) France Lwow, Poland 788 381 21 11.58 a.m. to 12 midnight. 10 a.m. to 12 mid night. Schenectady ... 790 379-5 500 11.45 a.m. to 6 a.m. 1 p.m. to 6 a.m. U.S.A. Hamburg 806 372 1-7 5.45 a.m. to 12.15 a.m. (approx.) 7 a.m. to 12 mid Germany night (approx.). Paris (Radio 811 370 1.0 12.30 p.m. to 10 or 10.30 p.m. 10 a.m. to 9.30 p.m. L.L.) Thurs. and Sats. earlier. France Opens Monday 10 a.m. Seville (Union 815 368 1-5 2 p.m. to 3 p.m. and 9 p.m. to 2 p.m. to 3 p.m. Radio EAJ 5) 11 p.m. and 9 p.m. to Spain 11 p.m. Fredriksstad ... 816 367-6 0-8 See Oslo (1083 m.). Norway Bergen 824 364 1-3 11.45 a.m. to 11 p.m. or mid 10.30a.m. to 11p.m. Norway night. or 12 midnight. Algiers 825-3 363-4 13 1.30 p.m. to between 11 p.m. 12.30 p.m. to N. Africa and midnight. midnight. Miihlacker 833 360 75 5.55 a.m. to 10.30 p.m. (Wed.), 7 a.m. to midnight. Germany 5.55 a.m. to midnight (Mons., Fridays and Sats.), sometimes till 1.30 a.m. on Thursdays and Saturdays. Graz ... 851 352-5 9-5 Relays Vienna 10.50 a.m. to Austria end. Own programme 6.15 p.m. to 6.45 p.m. on Sats., 12 and 3 p.m. every day. Barcolona (Radio 859 349 8-0 8.30 a.m. to 1 a.m. Mons. 8.30 a.m. to 10 p.m. Barcelona opens at 12 noon. EAJ 1) Spain Strasbourg 869 345 15 11.30 a.m. to 10.30 p.m. Weds, 10.45 a.m. or 8.30 France and Sats. Close down at 12 a.m. till 12 mid midnight. night. Brno...... 878 342 30 11.30 a.m. to between 10 p.m. 7 a.m. to 11 p.m. Czechoslovakia and 11 p.m. (approx.). Brussels (No. 2) 887 338.2 20 5 a.m. to 10.30 p.m. 5 a.m. to 10.15 p.m. Belgium Poznan 896 335 1-9 7.15 a.m. to 10.30 p.m. (Mon.), 7 9.30 a.m. to Poland a.m. to 12 midnight (Tues.), 12 midnight. 7.15 a.m. to 12 midnight (Wed. and Fri.), 7 a.m. to 10.15 p.m. (Thurs.), 7 a.m. to 12 mid night (Sat.). Naples (1NA)... 905 331.4 1-7 See Rome (441 m.). Italy Grenoble (PTT) 914 328.2 1-2 12.40 p.m. to 9.15 p.m. (approx.) 12.40 p.m. to 9,15 France p.m. (approx.). Paris (Poste 914 328.2 1-2 8.25 p.m. to 10 p.m., Fridays 8.25 p.m. to 10 p.m. Porisien) 7.25 p.m. to 8.30 p.m. France Breslau 923 325 1-7 6.30 a.m. to between 11 p.m. 7 a.m. to 12.30 a.m. Germany and 12.30 a.m. ______ 27 BROADCASTING STATIONS—continued. EUROPEAN STATIONS. {In decreasing order of Wave-length.) Fro- quency Wave- Power Hours of Transmission. Station in Kilo length in and cycles in Kilo- Country. per Metres. watts. Weekdays. Sundays. second. Goteborg 932 322 150 See Stockholm (436 m.). Sweden i Dresden 941 319 0-3 See Leipzig (259 m.). Germany Marseilles(P.T.T.) 316950 1-5 12.15 p.m. to 9.45 p.m. or 1 p.m. to 9.30 p.m. France 10 p.m. Paris (Radio 951-8 315 0-5 8 p.m. or 8.30 p.m. to 9.45 p.m. 9 a.m. to 11.15 Vitus) p.m. France Cracow 959 312-8 1-5 11.40 a.m. to 12 (midnight). 9.15 a.m. to 12 Poland (midnight.) Genoa, Italy ... 959 312-8 1-5 See Milan (500-8 m.). Agen...... Station completely destroyed by France the floods of March, 1930. In process of reconstruction. Zagreb... 977 307-1 0-7 12.20 a.m. to between 10 p.m. 9 a.m. to 11.15 p.m. Jugoslavia and 11 p.m. Bordeaux 986 304 35-0 12 noon or 12.45 p.m. to 9.30 12 noon to 9.30 (Lafayette) p.m. p.m. (approx.). f France Huizen 1004 298-8 8*5 7.40 a.m. (approx.) to 11.10 p.m. 8 a.m. to 10.30 p.m. Holland or 11.40 p.m. Turin ... 1012 297 8'5 See Milan (500’8 m.). Italy Kosice 1022 293 2*5 11.30 a.m. to between 10.15 p.m. 7 a.m. to 11 p.m. Czechoslovakia and 11 p.m. i Limoges, France 1022 293-3 0-8 12.30 p.m. to 9.45 or 10.45 p.m. 8.30 p.m. to 11 p.m. f Lyon (Radio- 1049 286 0'8 10.30 a.m. to 10.30 p.m. 12 noon to Lyon) 10.30 p.m. i France Innsbruck 1058 283-5 0-6 Relays Vienna 10.50 a.m. to Relays Vienna Austria 11 p.m. Weather Report 10.50 a.m. - to from Munich 12.25. Own 11 p.m. programme 8 p.m. Fris. and Sats. 10.45 a.m. Copenhagen ... 2811067 1-0 7.30 a.m. to 11 p.m. or 12.30 a.m. 8.30 a.m. to 12.15 Denmark a.m. Bratislava 1076 279 14-0 11.30 a.m. to between 10.15 and 7 a.m. to 11 p.m. Czechoslovakia 11 p.m. Heilsberg 1085 276-5 75 6 a.m. to between 10.30 p.m. and 6.30 a.m. to 12.30 Germany 12.30 a.m. Closing down time a.m. very irregular. Rennes (P.T.T.) 1103 272 1-2 6.15 p.m. to 9.30 p.m. (approx.). 1 p.m. to midnight. France Relays Paris P.T.T1 Bremen 1112 270 0-3 See Hamburg (372 m.). Germany Kaiserslautern 1112 270 1-0 See Munich (533 m.). Germany Lille, France ... 1130 265-4 1-0 12.30 p.m. to 9 p.m. 9 a.m. to 9.15 p.m. Moravskd- 1139 263 11-0 11.30 a.m. to 11 p.m. 7 a.m. to 11 p.m. Ostrava Czechoslovakia Leipzig 1157 259-3 2-3 6.30 a.m. to 11.30 p.m. as a rule, 6.30 a.m. to 12 Germany occasionally to 12.30 a.m. or midnight. later. Horby 1166 257 150 See Stockholm (436 m.). Sweden Toulouse(P.T.T.) 1175 255 10 12.45 p.m. to between 10 p.m. 10 a.m. to 9.30 p.m. France and 11 p.m. (approx.). Gleiwitz 1185 253 5-6 See Breslau (325 m.). Germany 28 BROADCASTING STATIONS—continued. EUROPEAN STATIONS. (In decreasing order of Wave-length.) Fre- I quency Wave- Power Hours of Transmission. Station in Kilo- length in and cycles in Kilo Country. per Metres, watts. Weekdays. Sundays. second. |______ Juan-les-Pins 1205 249 1*2 12.30 p.m. to 1.30 p.m. and 8.30 12.30 p.m. to 1.30 (Radio L.L.) p.m. to 9.30 p.m. (approx.) p.m. and 8.30 France p.m. to 10 p.m. Berne 1220 246 1-1 See Schweizerischer Switzerland Landessender (459 m.). Cassel 1220 246 0-3 See Frankfurt (390 m.). Germany Linz ... 1220 245*9 0*6 Relays Vienna 10.50 a.m. to Relays Vienna till Austria 11 p.m. Own market reports 8.30 p.m. Own daily 7.30 to 8.5 p.m. programme 8.30 to 10 p.m. Basle ... 1229 244*1 0*65 See Schweizerischer Switzerland. Landessender (459 m.). Vilno ... 1229 244*1 21*0 11.58 a.m. to 12 midnight. 9 a.m. to midnight. Poland Stavanger 1247 240*6 0*5 Seo Oslo (1083 m.). Norway Niirnberg 1256 238*9 2*3 See Munich (533 m.). Germany Bordeaux (Radio 1256 238 3*0 11.30 a.m. to 9 p.m. 11 p.m. on 11.30 a.m. to 9 p.m. Sud-Ouest) Tues. France Christianssand 1274 235*5 0*5 See Oslo (1083 m.). Norway Kiel ...... 1292 232*2 0*3 See Hamburg (372 m.). Germany Aachen 0*3 Koln (Cologne) 1319 227 1*7 See Langenberg (473 m.). Munster 0*6 Germany Cork (6 CK) ... 1337 224*4 1*5 Seo Dublin (413 m.). Irish Free State. Helsinki 1355 221 15 See Lahti (1796 m.). Finland B6ziors 1362 220 1/51 5 p.m. to 11 p.m. 8.30 p.m. to Franco 9.30 p.m. Flcamp 1364 219*9 1*0 12 noon to 9.30 p.m. 8 p.m. to 9.30 p.m. France (Normandy) Salzburg 1373 218-5 0*6 See Vienna (517 m.). Austria Flensburg 1373 218 0*61 See Hamburg (372 m.). Germany Konig8berg ... 1382 217 0*9 See Heilsberg (276*5 m.). Germany EUROPEAN STATIONS. The European Station list given above has been prepared by the Radio International Programmes Services, Ltd., sole contractors for foreign broadcasting programmes to the London daily papers and provincial and wireless press. The hours of transmission are reduced to British Summer Time. A list of British Broadcasting Stations is given on page 24. A list of the principal Short Wave Stations will be found on pages 30 and 31. 29 BROADCASTING STATIONS.- )on tinned. SHORT WAVE STATIONS. (In decreasing order of Wave-length.) Fre ! I quency Wave- i Country.in Kilo length i Remarks. Station. cycles I in per ! metres, j second. ' Khabarovsk ... U.d.S.S.ll. ... 4280 70.1 6 a.m. to 1 p.m. Paris (Radio Franco 4915 61 Same as the long wave station. LL) Vatican City ... Italy ... 5965 50.26 8 p.m. Radio telephony. 8.30 p.m. Radio Telegraphy. Sunday 11 a.m., Liturgical address. Barcelona (EAJ Spain 6000 50 Mainly club-work between 8 p.m. and 25) 10 p.m. Moscow U.d.S.S.R. ... 6000 50 3 to 9 p.m. daily. Relays Trades Union station. Nairobi Kenya 6000 50 5 to 8 p.m. Motala ... Sweden 6012 49.9 ! Relays Stockholm 6 to 11 p.m. Sourabaya Java ... 6036 49.7 Experimental transmissions 12 noon to (PK3AN) 4 p.m. Vancouver British 6069 49.43 Columbia Johannesburg ... S. Africa 6072 49.4 ' 4.30 p.m. to 9.30 p.m. Vienna... Austria 6072 49.4 0.2 kw. Tuesdays 10 a.m. to noon ; Fri I days 2 to 3 p.m. ; Saturdays, 10 p.m. to 12 midnight. Bangkok Siam ...... 6085 49.3 12 noon to 2 p.m. Saigon ... Cochin China i 6122 49.0 Sundays, 4.30 to 5 a.m., and 10 to 11.30 j a.m. ; Mondays, Wednesdays, and Fridays, 12 midnight to 3 a.m., and 1.30 to 3 p.m. Pittsburgh U.S.A. ... 1 6140 48.86 Relays Pittsburgh (KDKA) Wednesdays, (W8XK) I Thursdays and Saturdays, 10 p.m. to 3 a.m. Winnipeg Canada 6147 48.8 ; 2 kw., 12.30 to 2.30 a.m., sometimes 10 p.m. to 4.30 a.m. Tegucigalpa ... Honduras 6170 48.62 | 2.5 kw., Mondays, Wednesdays, Fridays and Saturdays, 3 a.m. to 6 a.m. Bogota... Colombia 6237 48.1 j Transmits from 4 p.m. Casablanca Morocco 6250 48 Relays Rabat from 2 p.m. Constantino Algeria 6667 45 0.2 kw.,Mondays and Fridays from 11p.m. Madrid ... Spain 6972 43 Tuesdays and Saturdays, 9.30 p.m. to 12 midnight. Lisbon ... Portugal 6991 42.9 2 kw., Fridays, 11 p.m. Perth ... Western 7142 42 1 p.m. to 5 p.m. daily. Australia Singapore Malay 7195 41.7 Sundays and Wednesdays, 3.30 p.m. to Peninsula 5 p.m.; Mondays and Fridays, 2.30 p.m. to 5 p.m. Teneriffo Canary Islands 7211 41.6 0.5 kw. Zurich ... Switzerland ... 7230 41.5 Saturdays, 10 p.m. to 12 midnight. Bangkok Siam...... 7313 41 Transmissions irregular. Lyons ... Franco 7463 40.2 Daily (except Sunday), 8.30 p.m. to 1.30 a.m. Bogota... Colombia 7556 39.7 11 p.m. to 1.30 a.m., and 5 to 7 a.m. Tokio ... Japan 8108 37 Experimental Transmissions, 11 a.m. to 3 p.m. Bandoeng Java ... 8125 36.92 2 to 4 p.m. daily. Long Island ... U.S.A. 8650 34.68 11 p.m. to 2 a.m. on Fridays and Satur days. Rabat...... Morocco 9300 32.26 Sundays from 8 p.m. Mexico City ... Central America 9376 32 8 p.m. to 10 p.m. daily. Rio de Janeiro Brazil 9450 31.75 11.30 p.m. to 1.30 a.m. Buenos Aires ... Brazil 9465 31.70 11 p.m. to 1 a.m. Melbourne Australia 9510 31.55 9 p.m. to 3 a.m. Lyngby Denmark 9520 31.51 Relays Copenhagen. Schenectady ... U.S.A. 9530 31.48 11 p.m. to 5 a.m. daily. (W2XAF) Berlin—Zeesen Germany 9568 31.38 8 kw. Relays various Gorman Stations, chiefly Konigs Wusterhauson. 30 BROADCASTING STATIONS—continued. SHORT WAVE STATIONS. (In decreasing order of Wave-length.) Fre- i quoncy i Wave- j Station. in Kilo- 1 length I Country. cycles ! in Remarks. per | metros, second. Poznan Poland 9570 31.35 2.5 k\\\ Tuesdays. 1.5 p.m. to 2 p.m. Wednesdays, 8.30 p.m. to 10 p.m. ; Thursdays, 8.30 p.m. to 10 p.m. (approx.). Relays Warsaw. Eindhoven Holland 9584 31.30 Relays in 6 different languages. 6 to 8 (PCJ) p.m. (Thursdays and Fridays) are best for amateurs in the United Kingdom, Africa and the Orient. Saturday morn ing programmes (4 to 6 a.m.) arc dedi cated to Australia,Thursday and Friday night usually to Latin America and British Colonies in Central America. Havana Cuba ... 9584 31.30 Experimental Transmissions 8 a.m. to I p.m. Philadelphia U.S.A. 9590 31.28 Sydney Australia 9590 31.28 20 kw. hours of transmission variable. Herod i a Costa Rica 9994 30.0 11 p.m. to 12 midnight, and from 3 to 5 a.m. Bangkok Siam ... 10167 1 29.5 2 p.m. to 9 p.m., and from 3 a.m. to 6 a.m. Saigon Cochin China 10346 29.0 See under 49 metres. Buenos Aires ... Brazil 10350 28.98 20 kw. Paris (Eiffel ... Franco 10575 28.35 Time signals 7.56 a.m. and 7.56 p.m. Tower, FYB) Bandoeng Java ... 10632 s 28.2 See under 36.92 metres. Pontoiso (Paris) Franco 11698 25.63 Colonial station. Broadcasts to America from 9 to 11 p.m. Winnipeg Canada 11718 1 25.6 Seo under 48.8 metres. Romo (Prato ... Italy ... 11810 , 25.4 Relays Romo (1RO) 5 p.m. to 6 p.m., Smoraldo) and 7.40 p.m. to 11 p.m. Chicago ... U.S.A. 11840 25.34 Relays W.C.F.L. (Chicago Federation of Labour, on N.B.C. network). Calcutta India 11870 25.27 3.45 to 4.15 a.m., and 4.15 to 6 p.m. (except Sundays). Pittsburgh U.S.A. 11880 25.25 Relays KDKA, 7 p.m. to 3 a.m., Satur days, 3 a.m. to 4.30 a.m. Pontoiso (Paris) Franco 11897 25.2 Colonial station, broadcasts to Africa from 6.30 to 8.30 p.m. Funchal Madoira 12500 24.0 Rabat ... Morocco 12605 23.8 Sundays, from 12.30 or 2 p.m. Oakland U.S.A. 12845 23.35 Tuesdays, Wednesdays and Fridays, 7 to II p.m.; Wednesdays, 2 a.m. to 10 a.m. Bucharest Romania 13950 21.5 Wednesdays and Saturdays, from 8 to 11 p.m. Suva Fiji Islands ... 14430 20.79 9 to 11 p.m. Mexico City ... Central America 14634 20.5 8.30 to 9 p.m. Vatican City ... Italy...... 15120 19.84 11 a.m. Radio Telephony ; 11.30 a.m., Radio Telegraphy. Pittsburgh U.S.A. 15210 19.72 Relays KDKA (Pittsburgh) Wednesdays and Saturdays, 7 p.m. to midnight. Pontoiso (Paris) France 15234 19.68 Colonial station, broadcasts to Indo- China, 3.30 to 5.30 p.m. Schenectady ... U.S.A. 19.5615340 20 kw. Sundays, 7 p.m. to midnight. (W2XAD) Weekdays, 9 p.m. to midnight. Huizen...... Holland 17762 16.88 Programmes for Dutch East and West Indies. Transmits 3 to 5 p.m., and Thursdays and Fridays, 7 to 9 p.m. Bandoeng Java 18821 15.93 Relays on Mondays, Thursdays and Saturdays. NOTE.—This list has been prepared from the latest available data by the Radio International Programmes Services, Ltd., the sole contractors for foreign broadcasting programmes to the London daily papers and the provincial and wireless press. Short wave stations are more or less experimental, and their wavelengths, hours of transmission, and programmes are subject to constant revision. 31 SEE 0r»i»ex The supreme dry baltery STAND 8 MAIN HALL D.x.35 Batteries for L.T. and H.T. STAND 8 MAIN HALL N.20 55 and a copy of “The Year Book costs you only 11 j 6 “The Wireless and Gramophone Trader” has served the best interests of the Trade since 1923. Today it is acknowledged as the progressive weekly newspaper covering the whole trade. For seven successive years the * YEAR BOOK ’ has been published providing the trade with a wealth of technical and buying in formation classified for immediate reference. You will find both in active service on practically every trader’s desk. The cost is small, the information which they bring extensive and valuable. You cannot afford to be without them. Call at the ‘Trader’ Stand No. 55 and arrange for copies to be posted direct to your address. Or send remittance to “The Wireless &. Gramophone Trader,” St. Bride’s House, Salisbury Square, Fleet Street, London, E.C.4. A COMPLETE SERVICE OF ‘LIVE’ NEWS & RELIABLE INFORMATION 34 35 Columbia 1932 Columbia has advanced ahead of the times . . . the new season’s models include radio and radio- graphophones of super efficiency in performance and at amazingly low prices. The best in technical skill and workmanship has gone to their making. Every purse and every requirement are met by radio sets from £5, and radio-graphophones as low as £33 : 12 : 0. In design and price Columbia has advanced ahead of the times . . . NEW LOW LEVEL PRICES <# ■# COMPLETELY NEW MODELS See them on Stand No. 7 Hear them in Demonstration Room D2 COLUMBIA—the first and last 36 NEW 4-VALVE RECEIVER WITH MOVING COIL SPEAKER A long distance high power set of ultra modern design and appearance. One knob tunes three ganged condensers; no rcac- tion. Volume control also acts as the “off” switch. Coil excited speaker. Provision for connection to a gramo phone pick-up, and to an additional speaker Mains aerial attach ment. In Walnut Cabinet. For A.C. Mains. Model 352 23 Gns AMAZINGLY EFFICIENT RADIO-GRAPHOPHONE A:3E3a£ A highly efficient radio- graphophonc, em 7 bodying the latest 3 t msi«'i valve circuit with two Tfa.--- '~H^- screened-grid valves. Double band pass tun ing for great selectivity. Single tuning control, illuminated and .v. marked in wave lengths. Mains aerial equipment. Coil 1 excited speaker. Stan* dard Columbia Graph- ophonc equipment iV with electric motor. V Dark oak cabinet. For A.C. mains. Model 602 Gns. Also 4-valve Radio-Graphophone 40 Gns. and Electro-Graphophone 20 Gns. word in home entertainment 37 Programmes every day I pear every day printed in large clear type on the regular wireless page. In addition, hints and notes on the latest wireless de velopments appear daily. This is only one of the many regular features which ac count for the million a day sale of the Daily Mirror. Buy a copy, you will enjoy it, and will continue to read ! it every day. 38 GENERAL NOTICES. Offices. The Offices of the Organisers will be found in the vestibule at the Hammer smith Road entrance—National Hall. Press Rooms. The Press Rooms are situated to the left of the vestibule at the Hammer smith Road entrance—National Hall. Telephone Numbers. The Telephone Numbers of the offices of The Radio Manufacturers' Asso ciation in the Olympia building are as follows : National Hall, Shepherd’s Bush 4338 & 1535. Empire Hall, Ground Floor, Shepherd’s Bush 4476,. First Floor, 1837. A list of the telephone numbers of the Stands of the various Exhibitors is given on page 17 of this Catalogue. The telephone number of the Press office at Olympia is Shepherd’s Bush 1048/9. Hours of Exhibition. The Exhibition will be open to the public from 11 a.m. to 10 p.m. daily. Interpreter. An Interpreter is in attendance and may be found in the Press Rooms. Dancing. A Dance Floor is situated on the Second Floor of the Empire Hall, on which dancing will be permitted during two periods daily—in the afternoon and evening. Visitors’ Lounges. Lounges for the use of Visitors are provided on the Second Floor of the Empire Hall, situated beside the Dance Floor, and also in the Gallery of the National Hall. Catering. Catering by J. Lyons & Co., Ltd., caterers by appointment. The Addison Restaurant (" Trocadero ” Service) on the Ground Floor of the National Hall, the Cafe (Corner House Service) on the Gallery, and the Empire Cafe (Corner House Service) are all open for the provision of A la Carte Luncheons, Teas and Dinners. There are Buffets in various parts, and a Soda Fountain in the National Hall. Music. The Music throughout the Exhibition and on the Dance Floor will be produced by electrical reproduction from broadcasting or from gramophone records supplied by The Columbia Graphophone Co., Ltd., and The Gramophone Co., Ltd. Cloak Rooms. Cloak Rooms will be found inside the National Hall to the right of the entrance, and in the Empire Hall on each side of the entrance. Toilet Rooms. Ladies’ and Gentlemen’s Toilet Rooms are situated at the four corners of each Hall on the Ground and First Floors. British Radio Valve Manufacturers’ Association. A Room off the Galler)’’ of the National Hall has been placed at the disposal of the B.R.V.M.A., where the Secretary or other Official will be in attendance. Classified Directory of Exhibits. A Directory showing the names of Exhibitors of the various types of appa ratus is printed on pages 203 to 209. 39 WRITES FOR 7fie EVENING STANDARD Realising the importance of providing our readers with the most up-to-date informa tion appertaining to Wireless matters, the “EVENING STANDARD” has engaged the services of the well-known radio expert, Mr.Garry Allighan, whose articles are a daily feature of the paper. Each Friday a special feature appears, in which, in addition to the daily programme ma terial, reports on new apparatus and replies to readers* queries are dealt with. Therefore, read the paper con taining the latest and best news of the day backed by authoritative and well informed Wireless Notes. 4 Wbt Condon's Premier Evening Newspaper H. T. BEASLEY (Advertisement Manager). Telephone: CITY 3000. 40 PARTICULARS OF EXHIBITS. NATIONAL HALL: GROUND FLOOR. Stand No. Memoranda. 1 Wm. Dibben & Sons, Ltd., Southampton. This firm are exhibiting a full range of “ Monarch ” and “ Cromwell ” Receivers, comprising competitive “ Straight Three " battery-driven Receivers in Oak Cabinets of Pedestal and Table Types, both incorporating speakers. Low-priced “ Electric Two " Receivers in three or four models for both A.C. and D.C. Mains, including something entirely new in Radio Gramophones. Finally, a range of “ Screened Grid ” Electric Three Receivers, A.C. and D.C., all incorporating Moving Coil Speakers. O S. G. Brown Ltd. 19, Mortimer Street, W 1. Loud Speakers. Loud Speaker Units. Pickups. Headphones. Microbox Pickups. Receivers. Public Address Equipment. Electrical & Radio Products (1931), Ltd. 3 Empire Work9, Salfords, Redhill. PORTABLE RECEIVERS. ALL MAINS RECEIVERS. RADIO-GRAMOPHONES. ACCUMULATOR CHARGING BOARDS. H.T. BATTERIES. 41 Marconiphone RADIOGRAMS & RA0IO See opposite page for descriptions of Complete range A . The First and Finest of all Radio/ Stand No. National Hall, Ground Floor. Memoranda. A The Marconiphone Co., Ltd., ■ Radio House, Tottenham Court Road, London, W.l. MARCONIPHONE MODEL 535 is a G-vnlvo all-mains supcr-hoterodyno radio-gramophono, advanced in design, incorporating a number of unique features, and intended to copo with future, as well as present broadcasting conditions. Combining extreme range, selectivity, quality and volumo, this model will satisfy the most exacting critics. MARCONIPHONE MODEL 536—the Marconiphone Radio Autogram— is identical with Model 535, but incorporates the now Marconiphone automatic 8-rccord changing mechanism. MARCONIPHONE MODEL 330.—A 3-valvo all-electric radio-gramo phone, which, by specialised design, yields results well abovo the average for this typo of set. Compact in sizo, and attractively modern in design, its extreme selectivity, groat rango and realistic reproduction set a new standard for instruments of this typo. MARCONIPHONE MODEL 42 initiates a type of receiver which will find groat popularity in almost every homo. The walnut table cabinet, handsome and compact, houses a 3-valve receiver and moving-coil loud speaker of exceptional efficiency, selective and sensitive, and com bining excellent quality with generous power output. Provision is made for a mains aorial. MARCONIPHONE MODEL 66 is a now 4-valve scrconcd grid battery portable, distinguished alike in appearance and performance. Efficiency, simplicity, and quality of reproduction are all well abovo the average. Provision is made for an external aerial and earth, and for connecting a gramophono pick-up. Its very moderate current consumption gives tho batteries a long useful lifo. MARCONIPHONE MODEL 246.—This new all-electric radio will inevit ably create an ontircly new conception of 2-valvo performance. Special circuit arrangements make it remarkably selective, while its output is more than sufficient to oporato a moving-coil speaker at ample volumo. Tho dark oak cabinet is particularly neat and compact; simplicity of operation is noteworthy, while results both on radio and gramophono equal thoso of many moro expensive instruments. MARCONIPHONE MODEL 131 LOUD SPEAKER.—This now moving- coil loud speaker has established itself as pre-eminent for finest possiblo reproduction. Of tho Permanent-Magnet typo, it requires no mains or batteries, costs nothing for upkeep, and can be used anywhere. It incorporates a Universal Input Transformer, immediately adaptable to any Receiver. MARCONIPHONE MODEL 91 is the same instrument as Model 131, but offered in chassis form. MARCONIPHONE MODEL 132 LOUD SPEAKER.—Smaller and lightor than Model 131, this instrument satisfies the very great demand for superlative reproduction, compactness and modorato cost. The dark oak cabinet is built on the samo attractive design as the large model. Tho permanent-magnot system possesses many unique features, which make for extreme sensitivity and vivid reproduction. Universal Input Transformer is again provided. THE MARCONIPHONE PICK-UP—tho celobrated No. 10—is recognised as combining ovory desirable fcaturo for flawless reproduction of gramo phone records. MARCONI VALVES.—A complete range of Marconi Valvos—which aro used in evory important radio service—is a prominent fcaturo of this exhibit. New types includo metallised valves, a rango of D.C. mains valves, and important additions to tho ranges of Battery, A.C., and Roctifior Vulvcs of remarkablo and hitherto unapproachcd efficiency. In addition, tho following aro being rotainod as a result of tho continuously maintained demand for thoso models :— 560, 39 and 55 Receivers, 120, 90, 02 and 63 Loud Speakers; all Marconiphono Mains Units and Batteries. 43 MmiCHAEL PRODUCTS Supreme in the Highest Class Stand N- 5 X receivers x / of all / TYPES \ ' PORTABLE ' 12 BRITISH A.C.—MAINS-D.C. MONTHS MADE BATTERY GUARAN RADIO GRAMOPHONE TEE ^SUPERSONIC &/ \ SHORT / V WAVE We extend a hearty welcome to all visitors to inspect our LATEST PRODUCTS which we are confident will maintain this year as for the past 10 years their superiority in the Radio World. VISITORS FROM OVERSEAS WILL FIND PARTICULAR IN TEREST IN THE COLONIAL SHORT WAVE SUPERSONIC RECEIVER WHICH HAS BEEN SPECIALLY DESIGNED FOR THE EXPORT MARKET. LTD. LONDON L. MCMICHAEL SLOUGH 44 : Stand No. National Hall, Ground Floor. Memoranda. CJ L. McMichael, Ltd. Radio Engineers, London and Slough. Messrs. L. McMichael, Ltd., who are numbered among the pioneers of the Radio industry, having been engaged in the production of wireless apparatus before the days of broad casting, and are now in their eleventh year of successful Radio manufacture, confidently place before the Trade and public their range of receiving apparatus for the present season. Messrs. McMichael’s long experience in the design and con struction of Portable Receivers enables them again this year to offer a Portable Receiver of the suitcase type, which, both from the point of view of appearance, design and perform ance, will, they believe, fill a definite demand. Supersonic Receivers are included in this year’s programme, and the experience of this firm in the early years of its history in connection with Supersonic design will undoubtedly give a strong measure of interest to these exhibits. All Mains Receivers, working from both alternating and direct current mains, incorporating many unique features and with up-to-date circuit design, will add to the interest of their display. The new McMichael All-Electric Radio Gramophone will be an important feature in this year’s exhibition of McMichael products. Visitors from Overseas will find particular interest in the Colonial Short Wave Supersonic Receiver, which has been specially designed for export trade by this firm, who would take this opportunity of welcoming Overseas visitors to their Stand. 45 mlie3 m«we3 Not only docs THE TIME! publish every day, with X tie full Wireless programme JBroad- casting Notes of especial intcj^st to listeners, but also ritji m its columns ma be found latest news/and the'most aiuh-7 oritatiy*ropinions upon 1 the morj important items/which are broadcast/— the;i^News, Sport, Music rt, Politics, the Theatre, Social7 Events everything Make If Oflje artme£ -m • -a Stand No. National TTall, Ground Floor. Memoranda. ^ Ready Radio, Ltd., 159, Borough High Street, London Bridge, S.E. 1. Offices & Works : Eastnor House, Blackheath, S.E.3. Ready Radio are best known as the suppliers of Kits of Com ponents for the construction of Receivers. So highly organised is this branch of their activities that they claim to be able to give immediate despatch of the complete Kit for any receiver described by the technical journals. The Kits not only include all the components and a panel drilled to specification, but also the bolts, nuts, screws and specially prepared eyeletted wire for connections. The constructor consequently has the assurance that when he purchases a Ready Radio Kit absolutely everything he needs will be included and the pleasure of assembling the receiver will not be marred by any annoyances. The actual wiring of receivers is greatly facilitated by the use of “ Jiffilinx,” which are various lengths of semi-flexible wire, insulated and fitted with eyelets at each end so that soldering is eliminated and the only tools necessary to the constructor are a screwdriver and pliers. Exhibited on the Stand are examples of various Kits, together with receivers constructed with Ready Radio Kits. In order that every constructor may have confidence that his receiver will give entirely satisfactory performance he has the privilege of applying to the Ready Radio Service Depart ment for information or advice regarding the construction and operation of his receiver. This Department is in charge of Mr. G. P. Kendall, the well-known radio expert and designer of many sets which have achieved fame for their outstanding merit of performance. Mr. Kendall is in attend ance at the Ready Radio Stand, and will be pleased to answer questions or give advice regarding the construction and operation of receivers. Ready Radio, in addition to supplying Kits of Parts, also make a wide range of components of their own, which, although very reasonable in price, are of the highest efficiency and guaranteed to give satisfaction and service to their users. Outstanding amongst these is the new “ Instamat ” Output Transformer. This transformer enables the constructor to match the output of his set perfectly with whatever type of speaker he may be using, so assuring himself of the best possible reproduction obtainable from set and speaker. It is a component which will be welcomed by every constructor as well as by listeners who already possess manufactured receivers. It is made in two types, one for moving-coil speakers and the other for high-resistance speakers, and every visitor should make a point of obtaining information as to the many advantages of this new Output Transformer. 47 THE RADIO TIMES Are you one of the ten million people who read the Radio Times every week? The Radio Times gives programmes in advance for a whole week— from Sunday to Saturday. It enables you to plan your listening ahead. It gives intelligent information about artists and features in the pro grammes, which are well worth reading. — Order it today! It costs 2d. every Friday. WORLD RADIO Do you listen to foreign programmes? If you do then you will find World-Radio (the official foreign and technical journal of the B.B.C.) indispensable. It contains a great deal of important technical infor mation and gives seven-day programmes of all the main European (and many American short wave) stations, It costs 2d., and is published every Friday. THE LISTENER The Listener prints the texts of all important broadcast talks: in addition it supplies articles (by some of the best present-day critical writers) on art, literature, science, philosophy, etc. It is published every Wednesday, price 3d. Of all newsagents, booksellers and bookstalls 48 Stand No. National Hall, Ground Floor. Memoranda. 7 Columbia Graphophone Co., Ltd., 98-108, Clerkenwell Road, E.C. 1. THE COLUMBIA GRAPHOPHONE COMPANY, LTD., include in this exhibit Eight Radio Models, two Radio Grapho- phones, Electro-Graphophone, Moving Coil and Cone Loud Speakers. RADIO RECEIVING SETS. MODEL 350.—A new two-valve " All Electric ” Set with self- contained speaker. Single control. For A.C. and D.C. Oak cabinet. MODEL 351.—A new two-valve Battery Receiver with self- contained speaker. Supplied complete with valves, batteries, etc. In Oak Cabinet. MODEL 333.—A new Pedestal five-valve (3 I.D.H. Screen Grid) Receiver. Single control of illuminated dial calibrated in wave-lengths. Four tuned circuits. Moving coil (field excited) Speaker. For A.C. 200/250 volts. In Walnut cabinets only. MODEL 352.—A new four-valve Screen Grid Table Receiver with self-contained moving coil (field excited) speaker. Single control of illuminated tuning dial. Provision for gramophone pick-up. Mains aerial attachment. For A.C. and D.C. in Walnut cabinets. MODEL 306.—Four-valve Suitcase Screen Grid Portable. Single tuning with full-sized balanced armature speaker. Leather-cloth covered case. MODEL 307.—Three-valve " All Electric ” Screen Grid Table Model. Arranged for gramophone reproduction. Single illuminated tuning dial with wave-length calibration. Adjust able aerial coupling. For A.C. and D.C. Cabinet in Mahogany. MODEL 303.—Five-valve Portable for Battery or Mains operation. Single tuning dial. Fitted with turntable. In Oak cabinet. RADIO GRAPHOPHONES. MODEL 602.—A new Console Radio-Graphophone. Three- valve (2 S.G.) Radio, with double band-pass circuit. Single control of illuminated tuning dial. Mains aerial attach ment. Moving coil (field excited) speaker. Standard electric gramophone equipment, pick-up, etc. For A.C. or D.C. In Oak cabinet. MODEL 603.—A new four-valve (2 S.G.) Radio-Graphophone. Single tuning of illuminated dial. Mains aerial attachment. Moving coil (field excited) speaker. For A.C. or D.C. In Walnut cabinet. SPEAKERS. MODEL 325.—Balanced Armature 10-inch Cone Speaker in Cabinets of Oak, Mahogany or Walnut. MODEL 327.—New Moving Coil (field excited) Speaker with 7-inch cone. For A.C. or D.C. In cabinets of Oak or Mahogany. 49 c : ; \ O LY M PIA I LIMITED. KENSINGTON, W. MANAGEMENT Telephone SHEPHERDS BUSH 2871 The General Construction and E ng i neering Departments are always prepared to advise and assist exhibitors with their EXHIBITION STANDS & DECORATIONS. Designs and Estimates submitted free for STANDFITTING, SIGNWRITING, FURNITURE, ELECTRICAL AND i i ENGINEERING I WORK, &c„ &c. j 1 Telephones: GENERAL CONSTRUCTION DEPARTMENT Shepherds Bush 4028. ENGINEERING DEPARTMENT i Shepherds Bush 2871. 50 Stand No. National Hall, Ground Floor. Memoranda. Q Chloride Electrical Storage Co., Ltd., O Clifton Junction, Near Manchester. Improvements in design and lower prices are the keynotes of the Exide and Drydex Sales plans for the autumn*, and Stand No. 8, facing the entrance on the right hand side, is devoted to a full range of Exide Batteries and Drydex Dry Batteries for radio. Exide Low Tension colls are in four main categories :— (1) Series “C” in celluloid and glass containers, having a capacity range of G-120 ampere hours. (2) Series “ D ” Mass typo cells, which hold their charge for long poriods without detriment. (3) Tho Do Luxe series, types HZ and WZG, which possess the main characteristics of the Mass typo with the added ability to deliver heavy discharge currents when required. (4) Tho unspillable cells for Portable Receivers. Improvements have been made in the “ 1) ” series, and an entirely new moulded glass box has been designed in conjunction with a new improved metal carrier. Non-intcrchnngeablo terminals have been fitted and the positivo and negativo screw terminals aro not only shaped and coloured differently, but are of different size threads. A now improved moulded lid to obviato loose terminal pillars and crocpage of acid has been stan dardised, and provision made for an indicating label on which the name of the owner can bo inscribed. A new, largo diameter filler cap with vent, easy to screw and unscrew, has been fitted, facilitating topping up and tho taking of hydrometer readings. The Exide Gel-Cel typo battery is being produced in a comprehensive range for portablo sets. Ownors of portable receivers have the choice of an Exide battery with liquid electrolyte or with jelly electrolyte in a celluloid container of a size and shape suitable for their particular set. Tho extended range of Exide unspillable cells with liquid electrolyte com prises anothor outstanding feature of this year’s display. The celluloid container has many refinements of design, including a specially moulded lid, and a double base of tho shoe type. These colls incorporate an improved Exide unspillable devico, and have a very largo ampere-hour capacity. The batterios for tho suit-case type of receiver are designed so that the plates are completely immersed in electrolyte in both the carrying and operating positions. Specimens of all types of Exide High Tension Batteries are displayed, notable oxhibits being the WY10, which is designed for multi-valve i work; tho WT10 volt, which has a capacity of 10,000 milliampere hours; and the popular WH10 volt, with a capacity of 5,000 milli- ampero hours. These Exide High Tension units aro also displayed assembled together in batteries of 60 volts in polished wood crates of special design with shaped ends for “ stacking.” A new pattern inter-unit connector of antimonial lead is now supplied free with WH and WJ 10-volt units. Included in the display is a selection of looso plates, separators, and other component parts, illustrating tho construction and technical details of Exide Wireless Batteries. A representative exhibit of tho new Drydex Dry Battery by Exide will be shown in tho following series :— (1) Red Triangle series—intended for use with Low Power Receivers— are manufactured in a rango from 60-120 volts. (2) Green Trianglo series—for use with Low Power Receivers, but of superior quality, are manufactured in a rango from 60-120 volts. (3) Orange Trianglo sories, triple capacity—specially produced for High Power Receivers where the omission is of the order of 10 milliamperes and upwards. These batteries givo a long and eco nomical life, maintaining their voltage under heavy load. They are manufactured in voltages from 60— 120. (4) Blue and Yellow Trianglo series for Portable Sets aro designed to give the maximum capacity possiblo in a limited space and will be found suitablo for most popular sets. Bluo Trianglo series range from 63—126 volts, and tho Yellow Triangle series from 99—120 volts. GRID BIAS BATTERIES.—Tho Rod, Green, and Yollow Trianglo Grid Bias batteries will bo found bost in use with the corresponding High Tension batteries. Tho Green Trianglo battery is recommended for use with the Orange Trianglo H.T. unit. Full details aro available on tho Stand, and technical exports will givo i advice on all Battery problems. Particulars of tho Exide Service organisation of over 600 Agents, all expert battery men, who service all types of batterios throughout tho country, are also available. 1 ol c2 RECt?^° |n nearly a million and three quarter homes every day, the “ Daily Express ” earns and is given a splendid reception. Every important item of news and every kind of topical feature is broadcast to the British Isles through the medium of the “ Daily Express the newspaper that sets the pace in modern journalism. Listeners should make a special point of reading “ Your Wireless and Mine a daily commentary on the programmes by Mr. Collie Knox. DAILY EXPRESS 52 Stand No. National Hall, Ground Floor. Memoranda. Q Pye Radio, Ltd., ^ Radio Works, Cambridge. London Address: Paris House, Oxford Circus, W.l. PYE “ Q ” PORTABLE. Among the interesting exhibits on the Pye Stand will be the new Pye “ Q " Portable. This is a 4-valve, screened grid and pentode output portable receiver with single tuning control operating twin ganged condensers, accurately matched by hand adjustment over the whole tuning range. Exceptionally large volume without distortion. Approximately three times that previously obtained on battery-operated portable receivers. Low milli- ampere consumption. Both the complete chassis and the loud speaker are flexibly mounted in the cabinet, thus eliminating mechanical shocks and microphonic or acoustic back-coupling. In fact, the “ Q ” Chassis is practically an assembly of die castings, flexibly mounted on steel spring and rubber to insulate it mechanically and acoustically from the cabinet and speaker. Excellent selectivity (ample to separate the Twin Transmissions from Regional Stations within 3 miles of the Station), sensitivity and fidelity. Provision for external aerial and earth. Absolutely complete with all valves and batteries. Supplied in polished walnut cabinet or in attractive grained fabric. The Pye “Q Portable definitely establishes a new standard in value in a quality portable. PYE TWINTRIPLE PORTABLES. There are three Models— Battery Model, All-Electric A.C. Model, All-Electric D.C. Model. Each of these Models is absolutely self-contained, absolutely portable. Provision is made for frame aerial reception on all Models. Two screened grid stages. Single ganged tuning control accurately tuning 3 circuits simultaneously. Tuning scales calibrated in wavelengths. Extreme selectivity and range of reception. No cutting of side bands. Under normal conditions 30 to 50 stations at loud speaker strength can be obtained free from interference with one another. Strikingly realistic quality of reproduction. Tonal colouration accu rately proportioned. No reaction control. This enables tuning to be accomplished with exceptional ease and freedom from oscillation. Gramophone pick-up jack on all Models. Alternative speaker plug on all Models. External speaker can be used separately or both speakers together. Cabinets in beautifully finished walnut, with wings and headpiece also in walnut or in ebony, as desired. The Battery Model can also be supplied in rectangular cabinet, with strap handle. 53 ! WWi RST ?X- o*\o- xM''4 ^ H * * S.9* m y..' ; ft 1111 8 'rf P iSs gl B P P3 @3 I m If %i>V «•? ''o • ^5\0- \, ' v V i] 5** * V tU° *»■ _ Z$&(. e*\ tJ2?* gv^si&* Ig^gs^® *•' i » A A i A rMi][t ULTRA ELECTRIC LIMITED, ERSKINE RD., CHALK FARM, LONDON, N.W.3 l 54 * I Stand No. National Hall, Ground Floor. Memoranda. Ultra Electric Limited, Erskinc Road, Chalk Farm, London, N.W.3. i Radio Receivers, Radio Consolettes and Speakers comprise the Ultra display. All Mains Radio Receivers will include the following : The Ultra TWIN CUB 2-valve All-Electric Set, which is , designed complete with Speaker and Mains Aerial. The Ultra TIGER III 3-valve All-Electric Set, also complete with Moving-Coil Speaker and Mains Aerial. The Ultra PANTHER IV, a self-contained All-Electric Set I with Moving-Coil Speaker and Mains Aerial. The Tiger III and the Panther IV will also be exhibited in Consolette style complete as described. There will be a wide variety of speakers of the moving-coil and double-linen diaphragm types, the former including : The Ultra Major Moving-Coil for A.C. and D.C. Mains. The Ultra 95 Permanent Magnet Moving-Coil. The Ultra Imp Permanent Magnet Moving-Coil. The Ultra Minor Moving-Coil for A.C. and D.C. Mains. In the latter group the Ultra Air Chrome Double-Linen Diaphragm is continued for the new season, with the " Popular Fifty ” and the U 99 with their respective chassis as the final items in the programme. 56 THE STAND YOU WON’T FORGET/ The 1932 Models of the World- t famous R.G.D. carry many out R.G.D. show again standing improvements over last with an additional year’s model, which was awarded success the First Prize at Olympia. The introduction this year of a ‘POPULAR’ Popular model at a popular price MODEL brings the R.G.D. within the range of many more would-be possessors. The R.G.D. is undoubtedly the greatest achievement in Radio- Gramophone construction. [ R OLYMPIA STAND G NO 11 DEMONSTRATION ROOM D 15 n S3S Full range models n o f from 48 to 1 1S Gns. RADIO GRAMOPHONE DEVELOPMENT CO., LTD., 17-20, Frederick Street, Birmingham. 50 Stand No. National Hall, Ground Floor. Memoranda. 1 1 Radio Gramophone Development Co. Ltd., -*■ ■*- 17/20, Frederick Street, Birmingham. “ RGD ” De Luxe Radio Gramophone, Type A.C. S6, D.C. SO. Two screen grid valves, band pass tuning, single control tuning, 10-watt output stage tone control. “ RGD ” Super Radiogramophone. Seven-valve super- heterodyne chassis with single control tuning, medium and long wave bands, band pass tuning, 10 or 50-watt output stage. “ RGD " “ Popular ” Radiogramophone, Type A.C. P4, D.C. P4. Two screen grid valves, single control tuning, tone control, 10-watt super power output stage with moving-coil loud speaker and walnut cabinet. " RGD " four-valve Radio, Type PR.4. Two screen grid valves, single control tuning, super power output stage with moving- coil loud speaker and walnut cabinet. “ RGD " Super Heterodyne Short Wave Convertor, enabling short waves, 15-100 metres, to be received. “ RGD ” Pick-ups, Speakers, Amplifiers, etc. 1 O Bullphone, Ltd., New North Road, Barkingside, Essex. Kits of Parts. Speakers. Eliminators. All Radio Components. 57 cOIL WINDING Patented in all > Countries. without 4 WORRY demonstrated at STAND no. 2o7 Empire Hall, First Floor No finer tribute could be paid to our “ Douglas” and “Macadie” Coil Winding Machines than their universal adoption by almost every firm of repute in the radio and electrical trades. There is no coil-winding work k that cannot be performed more speedily, more \ efficiently and more economically with one of k\ these machines. The “ Douglas” machine illustrated above winds coils of any shape and any size up to 5 inches long and 4 inches in dia- meter, and counts the turns automatic- ally. On the right is an ingenious I attachment which cuts off paper ^ insertions of any length and ! delivers them into the coils at whatever intervals are required. Complete illustrated catalogue ft free on request. DOUGLAS We are exhibiting for the first time a AUTOMATIC new MACADIE British COIL machine with throughout. WINDERS belt-driven bead. I THE AUTOMATIC COIL WINDER & ELECTRICAL EQUIPMENT CO., LTD. WINDER HOUSE, DOUGLAS STREET, LONDON, S.W.l. Telephone: Victoria 3405-6. Telegrams: Autowinda, Churton, London. .08 Stand No. National Hall, Ground Floor. Memoranda. 1 'l Belling and Lee, Ltd., ^^ Queensway Works, Ponders End, Middlesex. Terminals, Insulated and Uninsulated, five types; Safety Plugs and Sockets, Twin Plug and Sockets, Twin Connectors, Wander Plugs, Spade Terminals, Radio Fuses, Fuse Holders, Screen Grid Anode Connectors, Terminal Mounts, Battery Cords, Volume Control, Bakelite Mouldings. A prominent and interesting feature of the Stand will be a demonstration of a process of manufacture. 1 A Telegraph Condenser Co., Ltd., **" ■ Wales Farm Road, North Acton, W. 3. Fixed Condensers of all types, including paper, mica, electro lytic (dry and aqueous). Special subdivided block types for set and eliminator manu facturers. Moulded-in mica types for direct wiring. High frequency condensers for transmitting purposes. A complete range of high voltage smoothing condensers. Non-inductive condensers for bye-passing. A complete range of general receiving set condensers. SPECIALISTS IN BRITISH INSULATED WIRES OF EVERY DESCRIPTION ALSO SUPPLIERS TO THE RADIO TRADE O F HIGH RESISTANCES, AS USED IN SPAGHETTI CORDS. TINSEL CORDS, BARE 8c BRAIDED RUBBER FLEXIBLES, INSULATION SLEEVING, ETC • I Etc. SEND YOUR ENQUIRIES TO: SCOTT INSULATED WIRE Co., Ltd., QUEENSLAND ROAD, LONDON N.7. Telephone: NORTH 3408 & 3409. THE Telegrams: SILCOTENAM." SIGN THAT GUARANTEES. 59 FERRANTI SPEAKERS i The outstanding quality of Ferranti Speakers is attained by intense research, careful selection of the materials used, great manu facturing facilities, and unrivalled experience in true reproduction. I It is these factors which establish Ferranti Speakers in a pre-eminent and predominant position. Chassis of Moving Coil Speaker ready for The Ferranti Standard mounting in Cabinet or on baffle board. Moving Coil Speakers are established as the finest re Nowcomesthe NEW Ferranti Inductor I r- producers of radio speech Speaker, which approaches very and music that science has closely to the quality of reproduction yet devised, and maintain of the best moving coil speaker, but i that position by consistent is much lower in price. excellence of workman ship. — PRICES A.C. Mains energised, Moving Coil Type,A.I. Chassis only £9 10 0 D.C. „ „ D. I. „ £5 17 6 STAND it *> h D.C. ,, ,, ,, ||,, ,, D.2. » .. *2 5 0 Permanent Magnet „ „ M.l. „ £9 10 0 No. 45. ii »> ii ii ii ii ii M.2. ii „ £5 10 0 ii ii ii ii it M.3. ii „ £3 10 0 Inductor Speaker, Chassis only - £3 10 0 All models also available in cabinet form. FERRANTI Ltd. HEAD OFFICE & WORKS; HOLLINWOOD, LANCASHIRE. Londoni BUSH HOUSE ALDWYCH - W.C.2I 1 Stand No. National Hall, Ground Floor. Memoranda. 1 C The National Accumulator Company, Ltd., ^ ^ 50, Grosvenor Gardens, London, S.W.l. The National Accumulator Co., Ltd., exhibit on their Stand Accumulators for all radio purposes, both low and high tension models being available. This range of Accumulators . are marketed under the name DAGENITE ACCUMU LATORS. A unique feature of Dagenite Accumulators is the tell-tale device, which visibly indicates the state of charge of the cell at all times from fully charged to completely discharged. Hitherto this has only been available in the standard ranges of low tension accumulators, in glass or celluloid cells, but this feature has now been extended to embrace the popular thick plate type of low tension accumulators, and also the glass high tension accumulators. In the latter case, only two floats are used, and not three, as in the case of the low tension accumulators, one float being a charge indicator, and the other a discharge indicator. The standard series of accumulators (without the tell-tale device) are retained, and therefore the range of Dagenite Accumulators is particularly comprehensive, there being a I type available for every wireless purpose. The only low tension accumulators in which the tell-tale device is not available are those made up in moulded composition containers, and jelly acid types for portable receiving sets, the reasons being obvious. All these types may be inspected at the Stand of the National Accumulator Company, Limited. ■ 61 LOWEST inter-elect rode CAPACITY ever a 11 a i n e d TP HE actual amplification obtained from any Screened Grid Valve is largely governed by its inter-electrode capacity. Cossor research—during the past twelve 'Cossor 215 S.G. 2 volts. 15 months—has been focussed on this great amp. Impedance300,000 Amp problem. To-day we are able to announce lification Factor 330. Mutual Conductance 1.1 m./a. / v. that the new Cossor 215 S.G. has a lower Normal working Anode volts 120 Positive Voltage on inter-electrode capacity than any other Screen (approx.)60. Screened Grid Valve on the market. This Price 20/- capacity is of the order of *001 micro- ‘Cossor 220 S.G. 2 volts. 2 microfarads. Due to this—and also to i amp. Impedance 200.000 Amp many other important constructional lification Factor. 320 Mutual Conductance 1.6 m./a./v. advantages—the new Cossor 215 S.G. gives Normal working Anode volts 120 Positive Voltage on a degree of amplification with perfect screen (approx.)60. stability and freedom from distortion Price 20/- which—a year ago—would have been ‘This valve supplied with considered utterly impossible. Use this Metallised Bulk. new Valve in your Receiver and the all round improvement in its performance will astonish you. Stand THE NEW No. 16 A. C. Cossor, Ltd., Highbury Giove, London, N. 5, and at:— Birmingham, Bristol, Glasgow, Leeds, Liverpool, Manchester, Newcastle, Sheffield and Dubhn. Cossor i SCREENED CRID VALVES. i HIGHEST EFFECTIVE AMPLIFICATION O 8751 62 I Stand No. National Hall, Ground Floor. Memoranda. 1/^ A. C. Cossor, Ltd. ^ Cossor House, Highbury Grove, N.5. The Exhibit on Stand No. 16 includes the following range of products manufactured by A. C. Cossor, Ltd. :— VALVES. Amongst valves will be shown a complete range of battery valves for 2, 4 and 6 volts, including the latest type of Cossor valves constructed with the multiple point filament suspen sion, and Pentode and Screened Grid valves with the Cossor special construction, ensuring low inter-electrode capacity and high efficiency. A complete range of Cossor Mains valves and Rectifying valves are also shown. Cossor Metallised valves in certain types in the 2-volt battery range and mains range are exhibited. COSSOR KITS. COSSOR EMPIRE BATTERY MODEL 234.—The new Empire 3-valve Screened Grid Kit is shown, this embodying several new features in Cossor kit construction, including special screening and metal base plate and improved cabinet work. A metallised Screened Grid Cossor valve is used in this Kit. COSSOR MAINS KIT MODEL 235.—This is a 3-valve Screened Grid Kit for operation from A.C. mains, and includes Cossor Rectifying valve and Metallised Cossor valves in the high frequency and detector stages. Automatic grid bias is provided, and low tension, high tension, and grid bias batteries are eliminated. The special screening features embodied in the battery kit 234 are incorporated in this kit. RECEIVERS. A complete range of 2, 3 and 4-valve Cossor Receivers for. battery and all-electric operation is shown. LOUD SPEAKERS. A range of Loud Speakers manufactured by A. C. Cossor, Ltd., is shown, including Moving Coil Speakers as incorporated in the all-electric receivers. COMPONENTS. Amongst the Components exhibited are Transformers, Mains Units, High Tension Units, Pick-ups and Volume Controls, manufactured and marketed by A. C. Cossor, Ltd. (53 ■\ VALVES Radio reception with the Lissen Receiving Sets has been reduced to a mechanical switching from station to .station; while the operation of the Lissen Radio Gramophone, with its superb repro duction of electrically recorded gramophone items, is even more simple than the use of an ordinary gramophone. BATTERIES Types vary from a low-priced battery-driven seli- containcd Set—which gives amazing volume from all the home stations by reason of its special Lissen Power Pentode Valve—to the wonderful all-electric Lissen 4 valve Pedestal Radio Gramophone with a JiSSEn radio range of over 1,000 miles. Extended terms of payment are available on all models, and home demon strations are gladly arranged by any Lissen dealer. COMPONENTS Sets built [even one short year ago are now noticeably sur passed by these new Lissen Receivers. But old sets ra ay well be brought up to the new standard by rep lacemcnt ol JiSSEn the important components with the latest Lissen parts. Get the Lissen catalogue; examine these high-quality components for yourself and see RECEIVERS how the ‘ precision" standard has been maintained ; and remember that Lissen have spent a fortune in establishing and simplifying this range of "the parts that pull together” ALL so that you may buy and build with confidence. STAND IiSSEn r 17 rot HOME ENTERTAINMENT / G4 Stand No. National Hall, Ground Floor. Memoranda. 2^ Lissen, Limited. Liasenium Works, Worplc Road, Ialeworth, Middlesex. In addition to the popular range of Components and Accessories covering all parts of Radio Receivers, this exhibit will be particularly interesting by its display of Radio Gramophones and complete Receivers of distinctive character and to suit all requirements. An early visit should be made to the lessen Stand in the centre of the National Hall. EISSENOEA RADIO GRAMOPHONES.—Operated from Batteries or Mains with Frame or Outside Aerials incor porating the very latest circuits, particular attention having been paid to modern improvements. EISSENOEA RECEIVERS.—Two, three, four and five-valve Cabinet, Portable and Transportable models constructed entirely of lessen products. EISSENOEA EOUD SPEAKERS.—Special new design in chassis form or complete in most attractive cabinets. EISSEN VAEVES.—A complete range of New Process Valves of all types. EISSEN DRY BATTERIES.—A complete range of Batteries for wireless and domestic use. LISSEN ELIMINATORS.—For A.C. or D.C. Mains. EISSEN NEEDLE ARMATURE PICK-UP. EISSEN ACCUMULATORS.—A wide range of glass and celluloid cased Accumulators for Low and High Tension Supply. EISSEN COMPONENTS, including :— Coils and Holders. Fixed Condensers, Mica, Mansbridge and Power. Variable Condensers and Drum Controls, New. Resistances, Grid Leak, Flexible, and Cartridge type. Variable Resistances for all Radio uses. Jacks and Plugs. Resistance Capacity Coupling Units. Switches. The famous Lissen range with some new additions. Transformers. Various types in many ratios. H.F., E.F., and Output Chokes with some new designs. Valve Holders. New. Loud Speaker Units. New. Headphones. Turn Tables. Panel Brackets. Valve Adaptors and sundry small Accessories. A special Exhibit will be made of Mouldings and Die Castings. 66 Milliard THE * MASTER. * VALVE IS IN MORE HOMES THAN YOUR DAILY PAPER ( 66 Stand No. National Hall, Ground Floor. Memoranda. The Milliard Wireless Service Co., Ltd., Mullard House, 111, Charing Cross Road, W.C.2. Mullard, the Master Valve, in all its many forms, will bo displayed as the main featuro of Stand IS. Receiving valves include the following prin cipal classes :— BATTERY OPERATED TYPES. The Mullard range includes screened grid, three-electrode and pentodo types for 2-volt, 4-volt and 0-volt low tension supply and has been extended by the addition of several new and highly efficient types, par ticularly in the 2-volt range, in which a new general purpose valve, typo P.M.1.I4L, a new power valve, P.M.2A, and a particularly eco nomical super-power valve, P.M.202, taking only 0.2 amp., are note worthy. The characteristics of many types, including the popular super detector, P.M.2DX and the super-power valve P.M.252, havo been considerably improved. A.C. MAINS TYPES. The Mullard range of indirectly heated valves for use in A.C. all-mains receivers is remarkably complete, a number of new valves possessing remarkable characteristics having been introduced. Screened grid typos have been augmented by the S.4.V.B., having a lower impedance than earlier indirectly heated screened grid valves ; a now 3-olcctrodo detector, typo 904V, has the enormous amplification factor of 85, and the popular 354V and 104V types are now mado with improved charac teristics. Two entirely new introductions, an indirectly heated super power triode, 054V, and an indirectly heated pentodo PEN 4V, give largo outputs, amply sufficient for operating moving-coil speakers. OUTPUT VALVES. The series of large power output valves for A.C. operation has been extended, the well-known D.O. (high voltage) series now containing types having dissipations ranging from 10 to 75 watts. The latest intro duction, DO/75, for operation at anode voltages up to 1,000, gives an undistortod output of 18,000 milliwatts. Several now A.C. Mains pentodes havo been introduced, including typos with anodo dissipations up to 25 watts. RECTIFIER VALVES. A revised standard series of full-wave rectifiers is now available with outputs ranging from 60 to 120 milliamps at voltages up to 1,000, the filament voltage being standardised at 4.0 volts. TRANSMITTING AND MODULATING VALVES. A selection of valves for use as modulators and transmitters in equipments of all sizes from the amateur installation to the largest broadcasting station will be on viow, and will include the latest types for short-wave working. HOME CONSTRUCTORS’ RECEIVERS. The Mullard 3 Receiver, Typo 1932, is a new receiver of advanced design, high selectivity and great power. Employing the popular screened grid, detector and Pentode combination, the set incorporates single dial tuning, constant ganging, and long and short wave switching. Highly efficient coils, specially designed for this set, and an ingenious positive and self-cleaning wavo-chango switch are notablo features. The receiver is available in kit form, with or without Walnut Cabinet. Complete sets, and sets in process of construction will be on view, illustrating the easo with which the kit can be assembled. SPEAKERS. The Mullard “ H ” Type Speaker is still in the first rank among moving iron instinments. An efficient 4-polo balanced armature movement with tapped speech coil giving a choice of 3 impedances, a 13-inch cone and handsome moulded grille aro notable features. G7 Stand No. National Hall, Ground Floor. Memoranda. Telsen Electric Co., Ltd., Aston, Birmingham. The range of Telsen Components has recently been extended, and this exhibit includes a full range of components for the amateur constructor. TELSEN “ ACE ” L.F. Transformer. »* TELSEN " RADIOGRAND L.F. Transformer. TELSEN “RADIOGRAND” Super Ratio L.F. Trans former. TELSEN Intervalve L.E. Transformer. TELSEN Multi-Ratio Output Transformer. TELSEN Output Transformer. TELSEN Pentode Output Transformer. TELSEN Bakelite Dielectric Differential Condenser. TELSEN Bakelite Dielectric Re-action Condenser. TELSEN Bakelite Dielectric Tuning Condenser. TELSEN Logarithmic Variable Condenser. TELSEN Pre-set Condenser. TELSEN Mica Condenser. TELSEN Mansbridge Type Paper Condenser. TELSEN L.F. Intervalve Coupling Choke. TELSEN Output Chokes (Tapped and Plain). TELSEN Heavy Duty Power Grid L.F. Choke. TELSEN H.F. Choke. TELSEN Binocular H.F. Choke. TELSEN Valve Holders (Four and Five Pin). TELSEN Radio Fuse and Fuse Holder. TELSEN Push-Pull Switches (Two Point, Three Point and Four Point). TELSEN Variable Selectivity Aerial Coil. TELSEN H.F. Transformer and Aerial Coil. TELSEN Loud Speaker Unit. TELSEN Loud Speaker Chassis. TELSEN Slow-Motion Dial. TELSEN Grid Leak and Holder. TELSEN Spaghetti Resistances. 09 TeUpKone T NORTH 2608 SHOP WINDOW B ; ESTIMATES AND DISPLAYS 3, DESIGNS EBEE i \ T si! □! □ m .. i - ~.... ■■ ■=& F STRUIT ALBION STREET WORKS RADIO RADIO 1924 [,i ■ 1928 it- f Jradio w cffipimgjSs 44 RADIO 1925 fU'^SSSl’ , 1929 1 l JRADIO r-»1:r \ >4' // RADIO 1926 fj r. i 7l 1950 IJ V radio! K, RADII 4 i n 1927 » 1931 i'. i i i ■ ^vira *1 tuiin m Ife r-' - m-M • 1. c ssaifl !— \ • ALBION fTBIJTT 123-125 WORKS CROMER iands for ALBION STRUT V I CALEDONIAN ROAD successful I STREET KINGSCROSS tYffiDONG STANDS*. KINGSCROSS 70 Stand No. National Hall, Ground Floor. Memoranda. 20 Six-Sixty Radio Company, Limited. Six-Sixty House, 17/18, Rathbone Place, W.1. I SIX-SIXTY (B.V.A.) Radio Receiving and Rectifying Valves i of all types. SIX-SIXTY Cone Speaker Units and Assembles. SIX-SIXTY Cone Paper. SIX-SIXTY Power Units to operate Radio Receivers from A.C. Mains. SIX-SIXTY Valve and Set Testers. SIX-SIXTY Combined Radio and Gramophone Volume Con ! trol and Switch. SIX-SIXTY Special Ganged Variable Condensers. SIX-SIXTY Valve Screens. SIX-SIXTY Valve Adaptors, Gramophone Pick-up Attach ments, Grid Leaks and Turntables. SIX-SIXTY Chassi-kits (Regd.) in a variety of cabinets, con sisting of a 3-part semi-assembled radio chassis which can be incorporated in simple receivers, self-contained midget receivers and radio-gramophones, both battery and mains operated. The 3-valve model exhibited has the Six-Sixty “ Pre-Selector ” Tuning, with triple gang condenser giving single knob control and providing extreme selectivity; metallised Six- Sixty S.G. and super detector valves with Pentode output valve ; provision for Gramophone pick-up ; the Six-Sixty patented combined switch and Radio and Gramophone Volume Control. 71 Radio Questions ANSWERED ------ r | 'RUE to its long tradition of acting as referee on matters of importance, the SUNDAY REFEREE is prepared to help wireless enthusiasts to get the best results from their sets. Wireless occupies a large place in our national life. It provides enter tainment as well as education, and, therefore, it is fitting that readers of this paper should have first-class information which will enable them to get the utmost enjoyment from the radio programmes. All the latest wireless news and developments are dealt with. The correspondent is a Radio Engineer of repute, and is able to satisfy the most fastidious listener. Read his notes in the Sunday Referee THE PAPER FOR INTELLIGENT READERS-----AND LISTENERS 72 Stand No. National Hall, Ground Floor. Memoranda. The Edison Swan Electric Company, Ltd. 155, Charing Cross Road, W.C.2. VAI/VES. A full range of amazing Mazda Valves, including A.C. and D.C. indirectly heated Mains types. LOUD SPEAKERS. A new range of B.T.H. R.K. Moving-Coil Instruments, in cluding :— “ Senior ” R.K. (A.C. Model) with Westinghouse Rectifier. “ Senior R.K. (D.C. Model). “ Senior ” Permanent Magnet R.K. " Minor ” R.K. (D.C. Model). “ Minor ” R.K. (Permanent Magnet). B.T.H. Cone Loud Speaker (improved Model). RECEIVERS. The “ Power Pentode Two ” All-Electric A.C. Model. Ediswan 3-valve Battery Model. RADIO-GRAMOPHONES. Ediswan “ Pentogram ” All-Electric A.C. Model, embodying R K Speaker, Electric Gramophone Motor, and All-Mains Receiver. 73 All-Electric (Radio Mains Units Mains Receivers Mains Components STAND No. 22 REGENTONE LTD., Regentone House, 21, Bartlett’s Bldgs., Holborn Circus, London, E.C.4. Telephone:Central 8745 (5 lines). 74 to Stand No. National Hall, Ground Floor. Memoranda. 22 Regentone, Ltd •9 Regentone House, 21, Bartletts Buildings, Holborn Circus, E.C.4. j MAINS UNITS. A complete range of units with outputs varying from 120 volts at 12 mA., to 200 volts at 100 niA., with a number of models specially designed and suitable for use inside all standard portable receivers. All units are housed in well-ventilated pressed steel cases, and are supplied ' complete with mains flex and adaptor. The flex lead in every case is detachable from the instrument so that, if l necessary, a longer flex lead may be fitted conveniently and safely. A special three-pin plug is fitted to the flex lead which allows of the unit being used on mains of inputs varying from 200 to 250 volts. Two L. T. Chargers, A amp. and 1 amp. output, are also available. MAINS COMPONENTS. Transformers and chokes specially designed for the home constructor for use with Westinghouse Metal Rectifiers. The " REGENTSTAT ”—A continuously variable wire-wound resistance in values up to 180,000 ohms and with a current carrying capacity in the lower values up to 100 mA. MAINS RECEIVERS. A two valve A.C. mains receiver completely built on one pressed steel stamping and housed in a walnut-finished bakelite cabinet, of British manufacture. The special attention given to selectivity makes this receiver suitable for use even within the immediate vicinity of main broadcasting stations. 70 Stand No. National Hall, Ground Floor. Memoranda. O'! Lotus Radio, Ltd•j Lotus Works, Mill Lane, Old Swan, Liverpool. The chief feature of the LOTUS Stand will be the new All- Mains Receiver, which constitutes a big advance in receiver manufacture. THE LOTUS TABLE CONSOLE embodies the following remarkable features :—the Maguavox Moving Coil Speaker, Mazda Valves, Single Knob Tuning, Hair-Line Selectivity, and a very good range. The circuit embodies Screen Grid, Detector, and Power Valves, and in the case of the A.C. Mains Model, Valve rectification is employed. Provision is made for a gramophone pick-up and the whole set is self-contained in a beautifully finished grained Walnut Cabinet. There are three models for A.C. Mains, one for D.C. Mains, and one for battery operation. This latter is similar to the Mains Sets but incorporates high quality balanced armature speaker in place of the moving coil speaker. All models may be purchased either for cash or on the hire purchase system. In addition to the receivers LOTUS RADIO Ltd. are featuring their range of new Components which includes Gang Con densers, Slow Motion Condensers, Coils, Transformers, High and Low Frequency Chokes, Switches, Valve Holders, etc. 70 I Stand No. National Halt., Ground Floor. Memoranda. 04 The General Electric Go., Ltd., “ ' Magnet House,.Kingsway, W.C.2. The Exhibit on this Stand includes the following :— OSRAM FOUR New Music Magnet Constructor’s Kit showing stages of assembly. GECoPHONE A.C. All-Power Unit with Conversion parts for use with the OSRAM FOUR New Music Magnet when required for operation on A.C. Mains. GECoPHONE Tiiree-Valve All Electric Receiver for A.C. Mains, Table Model. GECoPHONE Compact All Electric Screen Grid Receiver for A.C. Mains, Table Model with self-contained loud speaker. GECoPHONE Table Four All Electric Screen Grid Receiver for A.C. Mains, Table Model. GECoPHONE Four-Valve All Electric Receiver for D.C. Mains, Table Model. GECoPHONE Console All Electric Screen Grid Receiver for A.C. Mains, Floor Model. GECoPHONE All Electric Radio-Gramophone for A.C. Mains, Floor Model. GECoPHONE Four-Valve Battery Portable Receiver, Suitcase Type, Maroon. GECoPHONE Four-Valve Battery Portable Receiver, Table Model. GECoPHONE All-Wave Superheterodyne Six-Valve Receiver, Short & Broadcast Wave Receiver. GECoPHONE Bakelite Cabinet Loud Speaker. GECoPHONE “ Stork ” Plaque Loud Speaker. GECoPHONE " Stork ” Cabinet Loud Speaker. GECoPHONE Inductor Dynamic Loud Speaker in Cabinet. GECoPHONE Inductor Dynamic Loud Speaker, Chassis only. GECoPHONE Moving-Coil Cabinet Loud Speaker in Cabinet. GECoPHONE Moving-Coil Loud Speaker on Easel Baffle. GECoPHONE Moving-Coil Loud Speaker, Chassis only. GECoPHONE Accessories. A comprehensive range of OSRAM VALVES is shown on this Stand and also on G.E.Co. Ltd. Stand No. 77. Demonstrations during the period of the Exhibition are given in Demonstration Room D 8 in the Gallery of the National Hall. 77 a brilliant programme Tlic reason for tlie amazing and con tinued grow til in popularity of tlic 4 4 Daily Herald is not diflicult to tillderstand. Its bold and unbiased editorial policy, its up-to-tlie-minutc news, its sparkling pictures, its start of brilliant writers covering every field of interest, lias captured tlie enthusiastic support of every cl ass o f tlic community and placed it fore- most in tlic ranks ol National newspapers. Tlic informative articles and fcarlcss criticisms of Sidney A. JMoscley, tlie well-known wireless journa list and critic, will have instant appeal to every Radio enthusiast. Tell your newsagent to deliver the DAILY HERALD £10,000 regularly every day. FREE FAMILY INSURANCE DAILY HERALD 7# Stand No. National Hall, Ground Floor. Memoranda. I OCn Kolster-Brandes, Limited, "Cray Works, Sidcup, Kent. K.B.283 3-VALVE RADIO-GRAMOPHONE.—This instrument utilises a screened grid H.F. amplifying valve, detector and a high-voltage pentode output valve, an A.C. induction motor with 12-inch turntable and a K.B. 158 Pick-up. A high grade midget moving-coil speaker is incor porated, while the pedestal cabinet is of walnut. Model K.B.283, 100/250 volts, 50-G0 cycles. Model K.B. 283/25, 100/250 volts, 25-40 cycles. THE KOLSTER 6-VALVE SUPER HETERODYNE RECEIVER (A.C. Mains Operated).—Six valves, three of which are of the screened grid type, are used in this receiver. Tho receiver is designed for reception on three ranges of wave-lengths, viz. : Long Wave Range, 800-2,000 metres approx. ; Medium Wave Range, 190-570 metres approx. : Short Wave Range, 12-70 metres approx. A high grade midget moving-coil speaker is incorporated. Two modols are available :— K.B. 286, 200/250 volts, 50-60 cycles. K.B. 286/25, 200/250 volts, 25-40 cycles. K.B. 279 3-VALVE A.C. MAINS RECEIVER.—Tho K.B. 279 utilises a screened grid H.F. amplifying valve, detector and a high voltage pentode output valve. The clearly marked illuminated condenser scale is cali brated for direct readings of wave-lengths on both long and short wave ranges. A moving-coil speaker is incorporated. Model K.B. 279, 100/250 volts, 50-60 cycles. Model K.B. 279/25, 100/250 volts, 25-40 cycles. K.B.281 3-VALY E BATTERY RECEIVER.—The K.B.281 is tho battery version of the K.B.279 for uso whoro suitablo A.C. supply is not avail able. Tho receiver is housed in a walnut cabinet. THE KOBRA 3-VALVE BATTERY RECEIVER—The Kobra is a self- contained receiver employing a detector and two low-frequency stages. An adjustable cone loud speaker is incorporated in the oak receiver cabinet. THE KOBRA JUNIOR 3-VALVE BATTERY RECEIVER.—This model is identically tho same as tho Kobra Receiver, except that tho cabinet is smaller. THE K.B. BATTERY “ PUP.”—A two-stage receiver with an adjustable cone loud speaker in an oak cabinet, which houses both H.T. battery and L.T. accumulator. K.B. ELECTRIC “ PUP ” (A.C.).—Similar in appearance to the Battery “ Pup,” but designed for operation off A.C. Supply mains. Two modols are available :— K.B. 252, 100/120 volts, 40-60 cycles. K.B. 263, 200/250 volts, 40-60 cycles. K.B. ELECTRIC “PUP” (D.C. Model).—Similar to tho A.C. Mains receiver, but designed for Direct Current operation. K.B. PORTABLE RECEIVER.—A 4-valve portablo recoiver employing screened grid H.F. amplifying valve, detector and 2 L.F. valves. A ; turn-table is incorporated and a cone loud speaker with balanced armature is fitted in cabinet lid. Loather or oak caso. BRANDESET 3A (Model K.B. 106).—A three-valve battery operated recoiver in oak cabinet. K.B. 72 SPEAKER.—A cone speaker of tho balanced armature typo incor porating an output transformer. In oak, mahogany or walnut. Iv.B.232 SPEAKER.—An attracted armature typo cono speaker which will reproduce equally notes of various frequencies throughout tho entire musical range. Oak cabinot. K.B.287 SPEAKER.—A speaker ombodying a now type of movement with adjustable armature which will handle considerable volurao without chatter or distortion. Oak cabinet. MATCHED TONE HEADSETS.—Headsets which incorporate a special feature onabling both oars to hoar with equality. K.B. 198 WAVE TRAP.—An instrument which can be used for tho elimination of interference from both long and short wave stations. K.B. H.T. SUPPLY UNITS.—H.T. Eliminators for obtaining H.T. current from A.C. or D.C. electric supply mains. 79 Good Advertising : ; Good Advertising needs no praise. Results are reward enough. As Official Advertising Agents appointed bythe Radio Manufacturers'Association in 1930, we have this year again been solely responsible for the Advertising of the National Radio Exhibition. We invite enquiries from Manufacturers who are looking for modern Advertising conducted with rigid economy by a House whose business practices conform to the most exacting standards d»11’ Numbered among our Clients are: — Huntley & Palmers Biscuits Symington's Soups Electrical Trading Association Ltd. H.P. Sauce Fruit Trades Federations Henry Heath Hats Lea & Perrins Achille Serre Dyeing & Cleaning Co. Sanatogen, Formamint, Genasprin Punch Cigars Bryant & May Ltd. Turban Dates 14. Canadian Government Snowfire Cream D Bell’s Heat Appliances Bray Burners Berkeley Easy Chairs and Central Currant Otfice (Greek Govt.) v Upholstery Assurance Matches 80 I Stand No. National if all, Ground Floor. Memor'anda.- OA E. K. Cole Ltd. l L*\J “Ekco” Works, Southend-on-Sea< :: ’ EKCO ALE-ELECTRIC RADIO. ALL-ELECTRIC RADIOGRAMS FOR D.C. AND A.C. MAINS. ALL-ELECTRIC CONSOLE FOR D.C. AND A.C. MAINS. ALL-ELECTRIC RECEIVERS FOR D.C. AND A.C. MAINS. ALL-ELECTRIC CONSOLETTES (COMBINED SET AND SPEAKER). COMBINED ALL-POWER SUPPLY UNITS FOR A.C. MAINS. COMBINED H.T. AND L.T. CHARGER UNITS FOR A.C. MAINS. TRICKLE CHARGER FOR A.C. MAINS. HOME RECORDERS—“ EKCO ” RADIOCORDER. H.T. UNITS FOR A.C. AND D.C. MAINS. Si D LEWCOS Reed. LEAD THE WAY ? ?2i :• f THE LEWCOS SUPER. - HET COIL KIT (Reference S.If.K. No. 1) ! The above is an illustration of the new Lewcos Super-Het Coil Kit with which an eight kylo- cycle wave band separation has been achieved. This set consists of one triple wave band oscillating coil, two I.F. coils with pigtails and one I.F. coil without pigtail, and marks a new epoch in reception. PRICE 50/- PER SET Lewcos again lead the way with their unique Super-Het Coil Kit and with the new Lewcos THE LEWCOS DUAL Dual Range Frame Aerial. These com RANGE CENTRE- ponents have been especially designed for Mr. W. James’s famous Super-Het Receivers TAPPED FRAME and are particularly suitable for all sets of AERIAL this type. The Lewcos Dual Range Centre Tapped Frarr.e Aerial is now When ordering either of the above do not available in polished dark oak forget that the Lewcos Constant Inductance with maroon silk covered wind j Transformer, Reference L.F.T.3, has a ings or black with blue silk i covered windings. Wave length characteristic which makes it eminently suit ranges 235/550m and 1000/2000m able for Super-Het Receivers. when tuned with the '0005 m.f.d. Write for full descriptive leaflet. Rif. R. 71. condenser. Size 30 ins. high, 10 ins. broad by 3 ins. wide. VISIT Baseboard 6$ ins. square. OUR The Forerunner of Its Type. STAND PRICE EACH No. 27 « 32/6 1- LEWCOS RADIO PRODUCTS FOR BETTER RECEPTION l The London Electric Wire Company and Smiths Limited ' Church Road Leyton London, E. I o I 82 Stand No. National Hall, Ground Floor. Memoranda. 07 London Electric Wire Company & Smiths, Limited, Church Road, Leyton, London, E.10. lewcos radio components AS FOLLOWS :— Aerial Wires. Bases, Six Pin. Battery Leads. Binocular coils. Binocular coils (Dual Type). Centre Tapped coils. Chokes (H.F. & L.F.) Coil and Valve Bases. Copper Wire. Cords. Dual Coils (Screened Unit). Dual Coils (Baseboard type). Dual Coils (Binocular type). Eureka Resistance Wire. Flex. Frame Aerial (Dual Range). Frame Aerial Wire. Glazite Connecting Wire. Headphone Cords. L.F. Coil Bases. L.F. Transformers. Leading-in Wire. Lewcodensers. Lewcoflex. Litz Wires. Loud Speaker Cords. L.F. Transformer (5-1). L.F. Transformer (3-1). Matched Tuned Grid coils with screens. Oscillator Coils. P.V. & P.J. Coils. Resistance Wire. Screened Connecting Wire. Short Wave Coils. Six-pin Bases. Sleeving. Spaghetti Flexible Resistances. Standard six-pin Coils Super Coils. Super Heterodyne Coils. Triple L.F. Coil Units. Twin Two-Pin Coil Bases. Wires (D.C.C., D.S.C., Enamelled). " X ” Coils. S3 STRAKER BROTHERS LIMITED PRINTERS, STATIONERS & ACCOUNT BOOK MAKERS. m k : »«** S3I mglrmt--r:^*1 »-i* |§Sipf! -i HsHt!i- 3TJ V [1 IV ESP 5* I - i I j Jt«\ . r.-: P*J /■ : ~ ~. *. •. { A SECTION OF OUR MACHINE ROOM SHEWING SOME SELF-FEEDING MACHINES. We are Printers of many Journals and specialise in Color Printing, Offset Litho and Letterpress. Power Relief Stamping and Account Book Manufacturers. THE BISHOPSGATE PRESS 194-200, BISHOPSGATE, LONDON* J; si Stand No. National, Hall, Ground Floor. Memoranda. Oft Igranic Electric Go., Ltd •j 147, Queen Victoria Street, London. Radio Components, comprising :— TRANSFORMERS. CHOKES. CONDENSERS. RADIO-GRAMOPHONE MOTORS. PICK-UPS. CONTROL DEVICES. AMPLIFIERS. MICROPHONES. APPARATUS FOR THE DEAF. ALL MAINS EQUIPMENT. SPECIAL EQUIPMENT FOR CINEMAS, HALLS, DIRT TRACKS, FAIR GROUNDS, STEAMSHIPS, ETC. 85 Established A. PERTON, 1864 THE OFFICIAL* SIGN & TICKET WRITER TO THIS & 7S La La THE LaE^UDlNG EXHIBITIONS. Head Office : 5, BEACONSFIELD TERRACE ROAD, W.14. ’PHONE: SHE’ 3566 FOR IMMEDIATE SERVICE. SIGNS OF DISTINCTION on Wood, Metal or Fabric. SHOWCARDS TO SUIT ALL TRADES and Exhibits. Frames in Stock. POSTERS, BANNERS and STREAMERS Fixed Anywhere. SANDWICH BOARDMEN Supplied by the Day, Week or Month. : ■- ILLUMINATED SIGNS, complete with i Electrical Installations. i i NOVEL STANDS DESIGNED to Display Exhibits to advantage. i CUT-OUTS Designed and Painted. i 3, Beaconsfield Terrace Road, W.14. 5 PHONE FROM YOUR STAND for ECONOMY & SERVICE 86 Stand No. National Hall, Ground Floor. Memoranda. OQ Radio Instruments, Ltd •f ™ S Purlcy Way, Croydon. Telegrams : “ Instradio ” Croydon. Telephone: Thornton Heath 3211. RECEIVING SETS. Stenode Receiver, the latest design incorporating the improve ments of the patentees. 3-Valve Madrigal All-Electric Receiver for A.C. Mains. 3-Valve Madrigal All-Electric Receiver for D.C. Mains. HIGH TENSION UNITS. All-Insulated models, for A.C. and D.C. for use in portable and usual cabinet receivers. NICKED AIJ,OY COMPONENTS. “ Hypermite ” I,.F. Transformer. Hypermu I,.F. Transformer. <« Ilypercore ” U.F. and Smoothing Choke. “ Parafeed " D.F. Transformer. Magnetic alloy of nickel iron used in all the above components. Dual Astatic H.E. Choke. “ Dux " L,.F. Transformer. Mains Transformers suitable for light and heavy loads. Smoothing and Output Chokes. Transformers for Westinghouse Rectifiers. Transformers for Valve Rectifiers. Transformers for Push Pull Amplification. - Transformers for Various output arrangements. 87 BurTon Bal-herij Sets (Component's at -need more be said The Clitics We tested these Sets &* Components and have nothing but praise ------ The Riblic have taken to then wondering yet revelling in j their remarkable eopabSite We shall be pleased to demonstrate our latest productions— the greatest range of Battery Receivers and Components, also Speakers, ever placed at the disposal of expert or amateur. Can we lai you have all details ---- from the Stand or apply direct to C.F.tH. BURTON PROGRESS WORKS • WALSALL • ENGLAND Stand No. National Hall, Ground Floor. Memoranda. 'Jfj British General Manufacturing Brockley Works, Brockley, London, Go., Ltd., S.E.4. BRITISH GENERAL 1032 AERIAL TUNING UNIT. BRITISH GENERAL TRIUMPH TRANSFORMER. BRITISH GENERAL OUTPUT TRANSFORMER. BRITISH GENERAL ANODE UNIT. BRITISH GENERAL H.F. CHOKE. ! ! BRITISH GENERAL MIDGET TRANSFORMER. BRITISH GENERAL NEW LINES AND PRICES. ! C. F. & H. Burton. Progress Works, Bernard Street, Walsall. BurTon Empire Two Valve Receiver. Empire 3-Valve Receiver complete with Speaker. i Empire 3-Valve Receiver without speaker. Scries of Empire Constructors Kits. A.C. Battery Eliminators. D.C. Battery Eliminators. Loud Speakers. Loud Speaker Units. Bakelitc End Plate Variable Condensers. Air Dielectric. Metal End Plate Condensers. Air Dielectric. Variable Condensers. Bakelite Dielectric. Drum Control Condensers. Reaction Condensers. l Differential Condensers. Pre-set Condensers. Slow Motion Dials. BurTon Transformers. L.F. Chokes. Binocular Chokes. H.F. Chokes. Valve Holders, 4-pin. Valve Holders, 5:pin. ; 6-Pin Bases. Metal Cabinets. Bakelite Indicating Terminals. Rheostats. Resistor Controls. Lead-In Tubes. Change Over Switches. Multiple Contact Switches. Push-pull Switches. Universal Joints. Battery Cords. Angle Brackets. Grid Bias Clips. Brass Terminals. Erinoid Hook and Spade Terminals. Wander Plugs. Plugs and Sockets. SU OFFICIAL CONTRACTORS ! TO THE RM'A BROOKS&WHITE Electrical Engineers 10 Maclise Road, West Kensingtori,WI4 Shepherd’s Bush 262o SPFFD AND FFFIOErNJCY" 90 Stand No. National Hall, Ground Floor. Memoranda. QO Graham Farish, Limited, 153, Mason’s Hill, Bromley, Kent. GENERAL WIRELESS ACCESSORIES AND COM PONENTS including— SPEAKERS. Two types of Cabinet Speakers of modern cubist design finished in Walnut, Oak and Mahogany, and two types of Chassis Speakers metal housings and finished in crystalline enamel are shewn. CONDENSERS. Two types of fixed Mica Condensers. Bakelite cased, .“ Standard Condenser and “ Parvor ’’ type respectively, produced for Manufacturers. Capacities ranging from .00005—.01. P R E-SET CON D ENSERS. Range covering capacities between .00005 mfd.—.001 mfd. VARIABLE CONDENSERS. Bakelite Dielectric Condensers of log mid-line capacity variation and “ Differential ” type are shown including also constructors type which is provided with bakelite moulded case and terminal connections. AERIAL CAPACITY UNIT. Variable capacity Unit for inclusion in series with aerial giving control over selectivity. RESISTANCES—Moulded type. There is a large wattage type resistance called the “ Super Ohmite,” and a smaller type called the Ohmite for use in anode feed R.C.C. and Parallel feed circuits and for use also in eliminators. In addition are shewn Grid Leaks of the cheaper type called the Standard and Kone Kap for use in Grid Circuits. HOLDERS to accommodate the various types of Resistances. Holders in moulded bakelite are available. H.F. CHOKES. Two types of Chokes consisting of the Standard' arid Multi-wave choke. MULTI-WAVE COUPLING UNIT. An H.F. Coupling Unit utilizing Ohmite Grid Leak and Multi-wave H.F. Choke mounted on a base incorporating fixed mica condenser of correct capacity. AUDION R.C, UNITS. An R.C.C. Coupling Unit for low frequency circuits. VALVE HOLDERS. Rigid and anti-mierophonic types are available both consisting of bakelite mouldings with con nections brought out to terminals. PUSH PULL SWITCHES. Two and Three point push pull switches are included in the range exhibited. VOLUME CONTROL. Bakelite cased Volume Control for control of Gramophone Pick-ups and Grid Circuits of all types. I GRAMOPHONE PICK-UPS. A Bakelite cased Pick-up for attachment to existing tone-arm is shewn and in addition a complete Pick-up and Arm in one Unit, all moulded in Bakelite. SPEAKER UNITS. Audion 4-pole Differential type, also cheaper type using cobalt magnets entirely enclosed in Bakelite case. L.F. AND SMOOTHING CHOKES. A range of Chokes for use in L.F. circuits and for mains smoothing purposes is shewn. MAINS TRANSFORMERS, A range of Transformers covering various requirements. 91 MAINS UNITS MODEL A.C.290. ALL-MAINS UNIT, H.T., L.T., G.B. 2 Variable H.T. Tappings 0/100 and 0/120 Volts, and one fixed of 150 Volts. Output 25 m/A. at 150 Volts. L.T. Trickle Charger for 2, 4, and 6 Volt Accumulators, Grid Bias Tappings at 1$, 3, 9 and 16 Volts. Price - £6 10 0 or on easy payments. MODEL A.2. H.T. UNIT. 3 Tappings, 60/80, 90/100 and 120/150 Volts. Out put 12 m/A. For 1, 2 and 3 Valve Receivers. Price 52/6 or on easy payments. There are models to suit every set for A.C. or D.C. Mains YOU MUST NOT MISS THIS WONDERFUL “ATLAS” SHOW. NEW MAINS UNITS NEW COMPONENTS REDUCED PRICES STAND Nor Pentode Out put Choke. Six Tappings j provide 9 output ratios. ■ Price - 21/-. : COMPONENTS 92 Stand No. National Hall, Ground Floor. Memoranda* 11 H. Clarke & Co. (Manchester), Ltd Atlas Works, Old Trafford, Manchester. London Office : 60, Chandos Street, Strand, W.C.2. Telephone: 7130 Temple Bar. Glasgow Office: 24, Oswald Street. Telephone: 5119 Central. This exhibit is comprised chiefly of a wide range of Battery Eliminators and All Mains Units, both for A.C. and D.C. Mains, and should be of exceptional interest to those con sidering the conversion of their Sets to Mains or All-Mains operation. New lines from these people will also be shown for the first time as follows :— Pentode Output Chokes (Shrouded and unshrouded types). Low-Frequency Chokes. High-Frequency Chokes. Output Filters. Smoothing Chokes. Rheograds or Variable Resistances. Power Transformers. There are also shown specimens of the " ATLAS " Pirtoid Tubing for all types of Coil Formers. 93 ^5 ORMOND ! I ; ■v r- lira fit 'Sra! £3-50 \vi «•» In a new field of VJ endeavour Or- mond again takes the lead with a product of superb quality. Here’s a speaker for the man who demands the best in all things. A balanced ! frequency response renders reproduction “ as near to nature ” as reproduced sound can ever be. it 1 The construction is extremely robust, the whole being mounted as a complete chassis. The cone, speech coil and suspension are arranged to give a truly parallel action, to handle a heavy input without distress. A speech transformer is incorporated in the cabinet, terminals being provided with alternative ratios for matching with the valve used in the output stage. Catalogue No. Ri464» THE ORMOND ENGINEERING CO. LTD., ORMOND HOUSE, ROSEBERY AVENUE, LONDON, E.C.l ! Telephone: CLERKENWELL 5334-5-6 and 9344-5-6. r-- See Our Exhibits at STAND No. 34 k Stand No. National Hall, Ground Floor. Memoranda. ltd. The Ormond Engineering Co., Ltd•J ^ ■ Ormond House, Rosebery Avenue, London, E.C.l. The Exhibit of The Ormond Engineering Co. Ltd., includes a range of Loud Speakers and Receiving Sets in addition to a comprehensive display of variable condensers and other components. Among the products shown for the first time arc the Moving Coil and No. 3 Loud Speakers, and No. 0 Variable Condensers. The Loud Speaker series includes the No. 1 l'our Pole Adjustable Unit, No. 2 Unit, large and small Chassis, and types of Cabinet Loud Speakers. The Receivers include an All Mains Transportable, l'our Valve Screened Grid Cabinet and Suitcase types of Portable, Five Valve Cabinet and Suitcase Portables. Ormond variable condensers shown include the Logarithmic, Straight Line Frequency, Straight Line Wavelength, Low Loss types, with and without slow motion movement. Ormond Slow Motion Dual Indicator Dials, both large and small models. Geared Dials, Friction Control Dial, fast and slow movement, with ratio 55 to 1. 21- inch, 3 inch and 4 inch combined bakelite knobs and dials. L.F. transformers and L.F. chokes. Rheostats and Potentiometers. Radio Frequency Chokes. Air Dielectric Fixed Condensers and Moulded Fixed Condensers. Midget Differential and Neutralising Condensers. Single Coil Holders, Crystal Detectors, and Vary Condensers. Resistance Capacity Coupling unit. F'ixed Resistors. H.T. and Grid Bias Batteries. Push Pull Switches. Turntable, Lever and Rotary anti-capacity switches. In addition to the varied assortment of screws, screwed and turned parts, stampings, etc., we are making a feature of our Electro Plating, Bakelite Moulding, and Cabinet Making Departments. 95 % MODEL P 225. SUITCASE V. MODEL P 274, 12 GNS. H.P. TERMS.—11 Monthly Instal II.P. TERMS.—<£1 1 0 Down and 11 ments of 1 Guinea each. Monthly Instalments of £1 3 1 each. The new Suitcase 5 Receiver is of remarkable A Super Screened Grid 4 with the amazingly range and power, fully up to the high standards low current consumption of only 6 milliamps, of quality and workmanship and capable of housed in the exclusive E.R.P. Dome Case of receiving a large number of foreign stations real hide and complete with ring valves, and under suitable conditions. accessories, of British manufacturc. -o -o o ■o MODEL A 365. A Super All Mains Receiver for both Long and Short Wave, com. paring favourably with PEDESTAL TYPE any high-powered Receiver yet heard in ALL MAINS V. this country. Employing six valves, including rectifier, with three S.G. 25 GNS. valves, giving results at least equal to scvcn-valvc heterodyne receivers. H.P. TERMS.— The Cabinet work is an outstanding feature being not only beautiful in 12 Monthly appearance, but of solid quality and first - class Instalments of finish. This Receiver can £2 10 0 each. be supplied in Burr v Walnut or Mahogany. it <*■ •o o t ELECTRICAL & RADIO PRODUCTS (1931), LTD., SALFORDS, REDHILL. Telephone : HORLEY 404. \ 96 Stand No. National Hall, Ground Floor. Memoranda. TC The New London Electron Works, East Ham, London, E. 6. Ltd SUPERIAL : 100 feet. 50 feet. i ELECTRON : 50 feel. I 25 feet. EARTH MAT: Complete with 25 ft. Wire attached. EXTENSION WIRE : 50 feet (25 ft. double). 100 feet (50 ft double). 300 feet (150 ft. double). SIMPLE-STRIP : 12 feet. INSULATOR PINS : In oak, white, black and mahogany. ELECTRON SCREEN AERIAL : Master Patent No. 260089. 97 i EXAMINE THE NEW GRIPSO SHROUDED FAUDELS L1 7T nr.+ The HOUSE with i oo YEARS PLUG & SOCKET REPUTATION with the PATENT SPRING GRIP <>■ -O ->■*>■<> -0-0- Better than Official Factors lo the Screw Terminals B.V.M.A NOTHING TO EQUAL THEM FOR NEATNESS. Wholesale Distributors to all the Leading EFFECTIVENESS. SIM RADIO MANUFACTURERS PLICITY AND PRICE C°r,/ tocji 41“' NO ‘ $r''nt COMPLETE ^ .7 / SCREWS MAKERS OF *$& ( OR RIGHT ft* ANGLE BENDS “CORONET” 2. 10 FRACTURE THE FINE “CORONET” 3. ’*»/* / STRANDS OF WIRE “CORONET” S. MANUFACTURERS 5-Valve Suitcase Portable Model OF WIRELESS ,f'nB Kt ACCESSORIES “CORONET” 4. THE GRIPSO CO. ^ct% 32 VICTORIA ST. LONDON. S.W.I Screened Grid 4-Valve Phone: Victoria 2433 Suitcase Model “CORONET” IK ALL MAINS 1 RADIO RECEIVING SETS IksgasS These Models are being shown on STAND NO. 78 STAND No. 192 The perfect Earth — at last ! EMPIRE HALL. “GODWINEX” ww- cur rod I no EARTH TUBE Gives perfect earthing \ from the moment it is Tube ^ K \ installed, ’ for ever. of heavy gauge steel ” Will not corrode lilted wllli like copper. cast ]ioIn( and ^ Over 180 sq. FAUDELS Ltd., sieel driving cap. So ins. earth HEAVY LEAD COATING ing con- inside and nut Q/C Fuller Accumulator Co. (1926), Ltd. Woodland Works, Grove Road, Chadwell Heath, Essex. I ACCUMULATORS. Low Tension. ACCUMULATORS. High Tension. ACCUMULATORS. Jelly acid; unspillable, for Suitcase and Transportable Receivers. ! I DRV BATTERIES. High Tension. DRY BATTERIES. Grid Bias. DRY CELLS. m EBONITE .“^■w4 IN ALL grades, colours and finishes LARGE STOCKS FOR IMMEDIATE DELIVERY perfectly cut, ground edges PANELS DRILLING . SLOTTING . ENGRAVING r,rr mnflCS SECTIONS, .FORMERS, RIBBED AND PLAIN. WOUND TO SPECIFICATION 7oLE MAKERS OF THE POPULAR SERIES OF COMPONENTS SOLE MAKL* dAN1PAD RUBBER COMPANY LTD., ASK FOR LISTS. 'Phonu: BISHOPSGATE 7322/3.1 5 & 7. MARKET STREET, FINSBURY, E.C.2 99 LOOK AT THESE PRICES! For BATTERY OPERATION O h £9-17-6 i\ji For MAINS OPERATION ii k £13-13 DOMINION GRAND An absolutely self-contained screened grid three-v^lve s receiver, complete with built-in speaker and B.R.V.M.A. valves in a handsome cabinet, royalty paid. Ganged condensers. Single knob tuning. Illuminated window dial. Calibrated in wave lengths. Gramophone pick-up terminals, external loudspeaker sockets and combined selectivity and volume controls ore provided. b For BATTERY ) OPERATION £3-15 For MAINS OPERATION £7-10 BABY GRAND A self-contained two-valve receiver complete with built-in speaker and B.R.V.M.A. valves, in a handsome solid oak .i Cabinet, royalty paid. Tuning and reaction controls on side of cabinet. Three aerial tappings. Gramophone pick-up terminals and external loudspeaker sockets are provided. BROWNIE BROWNIE WIRELESS CO. (G.B.) LTD., Nelson Street Works, London, N.W.l. 100 Stand No. National Hall, Ground Floor. Memoranda. : 3 7 The Brownie Wireless Company of Gt. Britain, Ltd., Nelson Street Works, Mornington Crescent, N.W.1 NEW DOMINION MAINS S.G.3. This is an entirely new 3-valve screened grid, All Mains model, of attrac tive design, with built-in loudspeaker. Tuning is effected by a ganged condenser with single knob slow motion control. An illuminated dial window is provided with calibrated wavelengths. Gramophone pick-up terminals are also fitted, and an external loud speaker may be used if desired. The Set is designed so as to use the Mains as an aerial, although provision is made for an outside aerial if desired. The Set operates entirely from the Mains of 200-, 250-volts, 40-90 cycles, the valves used being A.C. Screened Grid, A.C.H.F. Detector, with Pentode output valve. Careful attention has been made to appearance and performance, both of which will satisfy the most critical taste, A combined selectivity and volume control is provided to allow for varying conditions of aerial and locality. NEW DOMINION BATTERY S.G.3. Another entirely new Receiver similar in appearance to the above, but for use with batteries. A Pentode output valve is supplied, and the ganged condenser and screen coils ensure remarkable performance. The loudspeaker incorporated is capable of taking exceptional volume, and room is provided in the cabinet for H.T. and Grid Bias batteries. BABY GRAND 2-VALVE MAINS RECEIVER. An All-Electric Set embodying a detector and Pentodo output valvo. Two main controls aro employed, viz., tuning and reaction control. Provision is made for 200-250 volts A.C. 40-90 cycles Three aerial tappings aro provided for varying degrees of selectivity as required by aerial and location. Gramophone pick-up terminals are provided, and an external loudspeaker can be used if desired. BABY GRAND 2-VALVE BATTERY RECEIVER. Similar in appearance to the Mains model as above. With Detector and Pentodo output valves, the cabinet accommodating all batteries. DOMINION CONSOLE. A 3-Valve Set arranged for detector and two L.F. valves. There are two main controls—tuning condensor and reaction control. A special selectivity device is fitted so that varying degrees of selectivity to suit aerial and location aro obtainable. This Receiver incorporates a built-in loudspeaker of excellent tone and quality, whilst all batteries aro housed in the cabinet. This model is supplied in mahogany. DOMINION THREE. This Receiver embodies a similar circuit to the Dominion Console, but is without the loudspeaker. All batteries are housed inside the cabinet which is of solid mahogany. Provision is made for gramophone pick-up. DOMINION LOUDSPEAKER. Balanced armature unit. Solid mahogany cabinet of attractive design. Will accept considerable volume without distortion. BROWNIE WAVE TRAP & SELECTIVITY UNIT. A wave trap designed to overcome interference. Particularly adaptable for thoso living near the Regional Broadcasting stations. The Wavo. Trap may bo oporated on long or short wave lengths. The Unit can also be used as a selectivity tuning unit for low wave reception. Other exhibits include :— No. 2 AND THE No. 3 CRYSTAL RECEIVERS. CRYSTAL RECEIVER ACCESSORIES. POPULAR TRANSFORMER. DOMINION VERNIER DIAL, etc. 101 DRY BAXTER]ES^ ACCUMULATORS M 'M'Jl >A d 1* 1:^»] [•] Advert, of Pertrix Ltd., 233 Shaftesbury Avenue. London, W.C.2. Phone : Temple Bar 7971 (5 /thes). Works: Reddilch, 102 i * Stand No. National Hall, Ground Floor. Memoranda. 2Q Colvern, Limited, Mawneys Road, Romford, Essex. i A complete range of Tuning Inductances, including :— Pre-selection Band Pass Units. Screened Dual Range Coils for ganging. * i Ultra Short Wave Coils. Interchangeable Ultra Short Wave Coils. 1 Dual Screened Ultra Short Wave Coils. ■i Dual Range Oscillator Couplers. Band Pass Superheterodyne Intermediates.- Single and Ganged Volume Controls. Wire Wound Variable Resistances. Fixed Resistances. Switches. ¥ Metal Screening Covers. Mil Metal Panels. :' i j Semi-Variable Balancing Condensers. Valve Screens. Lead-in-Tubes and Turned brass work. Ml | 30 Pertrix, Limited, ^^ Britannia House, 233, Shaftesbury Avenue, / r London, W.C.2. PERTRIX SUPER-LIFE Dry Batteries and Accumulators. I . i : PERTRIX Dry Batteries are available in five capacities, •; Ii ■ and for High Tension purposes can be obtained in all sizes, ■V from 45 to 150 volts. ■ i i j PERTRIX SUPER-LIFE ACCUMULATORS are supplied i in celluloid, glass and ebonite boxes in varying capacities which cover all requirements. THE " KAPTIVE KARRIER ” is a distinctive feature on the glass cells. 103 for the outstanding M \ \ Speakers of the V W Exhibition visit HO ST AND No. 40 “The name of Cclestion has come to stand for the best possible in Loud Speaker con struction.” CQiSIlOH Jlmaleur Wireless, c&he cVery Soul of eMusic Jlug. 1st, 1931. LOUD-SPEAKERS CELESTION LTD KINGSTON-ON-THAMES LONDON [SHOWROOMS lo6 VICTORIA ST: LONDON SWI 104 Stand No. National Hall, Ground Floor. Memoranda. AC\ Celestion Limited, B ^ London Road, Kingston-on-Thames. Those interested in quality reproduction will find the new Celestion range of loudspeakers of unusual interest. Both the cabinet and chassis models are exhibited together with the Wo Pickup, and in each case the design shows a quality which has become associated with the name “ Celestion.” The new M12 Cabinet Loudspeaker, in Walnut finish, has a most attractive appearance, whilst the senior model of this type, the M14, gives results par excellence, and will handle great volume without distress. For the Home Constructor requiring a first class chassis cone speaker, the M.12 Chassis just suits, and its quality of repro duction definitely compares with much more expensive models. In the Moving Coil range, the R.P.M. Permanent Magnet Models have already earned an enviable reputation. These i fine instruments, incorporating reinforced diaphragm, can be closely examined and heard in operation. Their finish is of the highest possible class, and both the R.P.M. 12 and R.P.M.8 can be obtained in beautifully designed cabinets, all of which are on view at this stand. A unique and interesting feature of the Celestion Wo Pickup is the automatic press button needle release, which allows a needle to be changed in less than two seconds. The curve of the Wo shows that its output is well up to the usual Celestion Standard. Three of last season’s models, the DIO, D12 and Z20, are also exhibited, and are being continued during 1931-32. 105 Reduce testing equipment to I MASTER INSTRUMENT r The AVOMETER Gives Direct Readings in Amps., Volts and Ohms. STAND No. 2o7 EMPIRE HALL, 1st FLOOR. rjTHE AVOMETER is a British standard first grade portable measuring instrument giving—at the turn of a single switch and using only one pair of leads— thirteen ranges of direct and accurate readings in Am peres, Volts or Ohms. No calculations of any kind No external shunts or multipliers. There are more Avoinctcrs in use throughout the world than any other combined measuring instrument. This is because it is the handiest and most dependable com plete measuring instrument known. Gives DIRECT Readings in AMPERES *1 milliampcre to 12 amperes. 0—12 amperes 0- 12 „ 0- 12 „ 0- 012„ VOLTS 1 millivolt to 1200 volts 0—1200 volts 0— 120 »» 0- 12 »» 0- 1*2 „ 0- *12 „ Entirely British OHMS *1 ohm to 1 megohm. 0—1,000,000 ohms 0- 100,000 „ 0- 10,000 „ 0— 1,000 „ AVOMETER : lRegistered Trade Marl) Price £8:8:0 13 Electrical Measuring Instruments in 1 or deferred terms. The AVOMETER is portable, THE AUTOMATIC COIL WINDER AND ^miiC„ed0mi?m:a“unre67l^ ELECTRICAL EQUIPMENT CO., LTD. 6£ x 4 inches,and weighs 5 lbs. Winder House, Douglas Street, London, S.W.l Telephone: Victoria 340316. Telegrams: Aulowinda, Cburton, London 106 Stand No. National Hall, Ground Floor. Memoranda. I /II Edison Bell Limited, Glengall Road, London, S.E.15. Radio Gramophones, All Mains. Super Het. All Mains. Transportable. Super Het. Battery Operated. Transportable. Three-Valve S.G. Band Pass Sets. All Mains. Four-Valve S.G. Band Pass Sets. All Mains. Baffle Moving Coil Speakers. Cabinet Moving Coil Speakers. Condenser and Carbon Microphones. Spaghetti Resistances. Pickups. Adaptable Gramophones. Mouldings. Pickup Units. Twin Turntable Amplifiers. Amplifiers. Condensers Preset. Jacks and Switches. Volume Controls. Scratch Filters. 1 Eliminators.. l 107 THE BEST IN THE WEST We are stockists for all leading makes of Wireless Receiving Sets, Components, Loud Speakers, Valves, Radiograms, Portable Sets, Talking Picture Apparatus, Amplifiers, Logarithmic Horns and Power Sound Units, Photo Electric Cells, Sound on Film Heads for Talking Pictures. Write or Call for Copy of our New Stupendous Catalogue for 1932. Free to Callers or Post Free 6d. DAYZITE, Ltd., Wholesale Wireless Dealers, Telegrams: 17, LISLE STREET, Telephone: TITLES, LEICESTER SQUARE, GERRARD 4476 WESTRAND, Two Lines. LONDON. LONDON W.C.2. 108 Stand No. National Hall, Ground Floor. Memoranda. ^2 Climax Radio Electric Ltd Havcrstock Works, Parkhill Road, Hampstead, London, N.W.3. Mains Receivers, Three Valve, incorporating Moving Coil Speaker for A.C. and D.C. Mains. Mains Receivers, Two Valve, incorporating Moving Coil Speaker for A.C. and D.C. Mains. Nickel Alloy Core L.F. Transformers. . L.F. Chokes. H.F. Chokes. Mains Transformers. Mains Units for D.C. Mains. Mains Units for A.C. Mains. Potential Dividers. Earth Tubes. (Copper and Galloy.) A'2 Partridge, Wilson & Co., * ^ Davenset Works, Evington Valley Road, Leicester. As in previous Olympia Radio Exhibitions, the apparatus displayed on this stand will appeal essentially to the Trade. This year, the comprehensive series of .Davenset Commercial Accumulator Charging Plants has been augmented by a range of Automatic Plants, which are almost uncanny in their simplicity of operation. All traders, who may be interested in Battery Charging, are well advised to inspect these new Automatic Equipments, which are aptly described by the manufacturers as the “ CHARGERS THAT THINK FOR YOU." In addition to examples of Davenset Static Rectifiers, illus trating their uses for a variety of purposes, a range of Set-Makers’ Mains Components is shown. lU'J THE Wholesalers of BIRMINGHAM & NOTTINGHAM Invite every Trader to call at their Stand No. 69 in the Empire Hall. The following big points will interest you:— 1. We were established before Broad casting started. 2. We are main distributors for the lead ing manufacturers. 3. We carry the largest stocks. 4- We give the quickest service. 5. We are known from John o’Groat’s to Land’s End. 6. —and our slogan, “If it’s good, We have it.” There are other good points besides. You will find these out when you start dealing with us. Telegrams : “ PEEANEF, BIRMINGHAM.” Telephone: MIDLAND 5941 (Private Branch Exchange). Proprietor: JOHN PRIESTLY. Main Offices, Showrooms and Warehouse: 3 to 11, CARRS LANE, BIRMINGHAM. Nottingham Depot: 59, FRIAR LANE, NOTTINGHAM. 1HJ Stand No. National Hall, Ground Floor. Memoranda. A A The Westinghouse Brake & ' ' Saxby Signal Go., Ltd •J York Road, King’s Cross, London, N.l. 'Phone: North 2415. METAL RECTIFIERS OF ALL TYPES FOR RADIO USE. High Tension, including the new model H.T.S, 250 volts, GO niilliamps (smoothed output). Low Tension. Grid Bias. Pot Excitation for Moving Coil loud speakers. BATTERY CHARGERS FOR CHARGING STATIONS. Single and multi-circuit type . RECTIFIERS FOR A.C. MEASURING INSTRUMENTS. i As applied to measurements of current and voltage in re ceiving sets, etc. Ill goodness int® it choose your circuit with care, and you with skill of which you are justly proud ; but no amount of care or skill on your part will make a first class set from second class components. Unless you buy sound components of guaranteed standard, you will be dis appointed in the set of which you hoped such great things. TRANSFORMERS CHOKES CONDENSERS Buy Ferranti and remove all ANODE FEED RESISTANCES doubt. Built to a standard RADIO METERS and not to a price, Ferranti VALVE TESTERS & MULTI-RANGE components repay any little SETS extra outlay by years of TRICKLE CHARGERS satisfactory service and unsur H.T. SUPPLY UNITS passed performance. Build MOVING COIL & INDUCTOR Ferranti into your set and you SPEAKERS will be proud of the results. VISIT STAND No. 45. FERRANTI COMPONENTS FERRANTI Ltd. Head Office and Works, Hollinwocd, Lancs. London : Bush House, Aldwych, W.C.2. 112 Stand No. National TTai.l, Ground Floor. Memoranda. JC Ferranti, Limited, " ^ Hollinwood, Lancashire. The apparatus demonstrated will consist of the following :— A.C. MAINS RECEIYERS. RADIO GRAMOPHONES. ! ! SPEAKERS. : AUDIO FREQUENCY, PUSH-PULL, AND OUTPUT TRANSFORMERS. ! JUT. SUPPLY UNITS. MAINS COMPONENTS OI< ALL KINDS. Technical Engineers will be in attendance to advise visitors on any point in which they are interested. 113 E STAMPINGS fOR- TRadio NSTRUMENTSm transformer Stanyozngs t£eaa-jjfione and J^oucf Spea/cer JDiapArealms made in STALLOY HIGH RESISTANCE STEEL ^ALLOh Ioseph Samkev&Sons Ijp ^ BILSTON, England. London: 168 Regent Street Wi. 114 Stand No. National Hall, Ground Floor. Memoranda. Af. Whiteley Electrical, Radio Co., Ltd., * ^ Nottingham Road, Mansfield, Notts. THE W.B. P.M.20 Permanent Magnet Moving Coil Loud Speaker (Super Cinema Model). THE W.B. P.M.l Permanent Magnet Moving Coil Loud Speaker. Also in Walnut Cabinet. THE W.B. P.M.2 Permanent Magnet Moving Coil Loud Speaker. Also in Walnut Cabinet. THE W.B. P.M.3 Permanent Magnet Moving Coil Loud Speaker. Also in Walnut Cabinet. Transformers for above. THE W.B. Cabinet Patent Cone Loud Speaker, Senior Model. THE W.B. Cabinet Patent Cone Loud Speaker, Junior Model. THE W.B. 4-pin Anti-phonic Valve Holders. THE W.B. 4 or 5-pin Universal Valve Holders. I THE W.B. 5-pin baseboard, 2 in. diameter. THE W.B. 4 or 5-pin Miniature, l|j in. diameter. THE W.B. 3 point Patent Push Pull Switches. i THE W.B. 2 point Patent Push Pull Switches. Screens, etc. Montague Radio Inventions and Development Go., L.td., Beethoven Works, Gt. College Street, Camden Town, N.W. BEETHOVEN RADIO—MADE IN LONDON. This Stand is entirely devoted to the display of the BEETHOVEN SCREEN GRID MINOR FOUR PORTABLE RECEIVER. Associated with the Receiver, are the finest traditions of the House of Beethoven ; and whilst its appeal is to those who desire a first class instrument, yet its popular price places it within the reach of all. The small size and weight make this Receiver a pleasure to carry from place to place, if so desired. Although a Portable Instrument, it has been designed with a view to satisfying the most discriminating tastes of those to whom Home Furnishing is of paramount importance. The Case Work is of Blue Lizard Grained Material, while the interior woodwork is carried out in highly polished halved Mahogany in conformity with the modern ideas in Cabinet Making. The Receiver although being comparatively small is capable of giving huge volume, and great range, even under the most exacting conditions, while the quality of reproduction leaves nothing to be desired. 115 r.2 SWIFT LEVICK & SONS, LIMITED, Our Patented Moving Coil Loudspeaker Cobalt Steel Permanent Magnet has achieved such a phenomenal success since its introduction two years ago that our Exhibit this year is confined almost exclusively to these Magnets and to a battery of Loudspeakers actually illustrating the main types in action. British Letters Patent No. 310207. Visit our STAND No. 52 which will be in charge of Mr. G. D. L. Horsburgh, A.M.I.Mech.E., the actual Inventor of these Magnets, who will demonstrate them to you. CLARENCE STEEL WORKS, SHEFFIELD. 110 Stand No. Memoranda. EMPIRE HALL: GROUND FLOOR. Carrington Manufacturing Co., Ltd., ^ Showrooms & Sales Dept., 24, Hatton Garden, Holborn Circus, London, E.C. Holborn 8204. Factory, “Cameo” Works, Sanderstead Road, South Croydon. Croydon 0623. A Complete range of modern design Radio Casework in Oak, Mahogany and Walnut. CAMCO Cabinets for Radio-Gramophones. CAMCO Cabinets for All Mains Receivers. CAMCO Cabinets for Portables and Transportables. CAMCO Cabinets for Loud Speakers. The “ Melodee ” Cabinets. CAMCO Cabinets for the Manufacturer and Constructor. CAMCO Cabinets as specified by leading Radio Engineers, and those specified in ” Radio for the Million.” CO Swift Levick & Sons, Ltd., Clarence Steel Works, Sheffield. Levick’s Patented Moving Coil Loudspeaker, Cobalt Steel Magnets showing various types manufactured. A battery of Loudspeakers illustrating these Magnets in actual action. Various Magnets for Pick-ups, Moving Iron Speakers, Headphones, etc. C2 Mains Radio Gramophones, Ltd., Vaughan Street, Bradford. All Mains Reproducing Apparatus, comprising the M.R.G. '* Regionagram,” and Multi-Valve Radio-Gramophones, Amplifiers, and Receivers. Moving Coil Speakers and Units. CJ. John S. Downing & Sons, Ltd., ^ ■ Crown Works, Commercial Street, Birmingham. Manufacturers of " Crown ” Series Wireless Cabinets. re “The Wireless & Gramophone Trader,” OO Proprietors: The Trader Publishing Co., Ltd., St. Bride's House, Salisbury Sq., Fleet St., E.C.4. ” THE WIRELESS AND GRAMOPHONE TRADER.” Every Saturday, established 1923. A weekly Trade Journal of the Wireless and Gramophone industries. Provides a review of trade development, tests and selling reports of / apparatus, selling, advertising and display, hints for re / tailers, financial and commercial information, etc. / " the wireless and gramophone export TRADER,” a monthly review of trade development at home and overseas, for dealers in all countries. “ thE YEAR BOOK AND DIARY,” a buying, technical and trade directory, published annually. 117 SEE HOME RECORDER Trade Mark■ on Stand 220 HEAR Empire it in our recording IIATEVER you do at the Studio and Show—don’t miss Stand w 220 in the Empire Hall ! Demonstration There you will see the Fay Home Recorder—the amazing new in vention that reproduces your Room favourite tunes from the Radio and your own and your friends’ voices with astonishing realism. You will see, on Stand 220, the three models, the Acoustic Re National Hall cording at 2 guineas, the Electric Recording Model at 5 guineas, and the Super Electric Recording Model at 12 guineas. And then in our Recording Demonstration Studio (D.7 National Hall) you will be able to hear 6", 8", 10" and 12" records made and then played back, immediately ! Telephones: VICTORIA 7784 & 5. FAY” HOME RECORDERS, Ltd. Telegrams: 121, Victoria Street, Westminster, S.W.l. “FAYEDISK, SOWEST, LONDON.” 118 Stand No. Empire Hall, Ground Floor. Memoranda. Rolls-Caydon Ltd., Rolls-Caydon House, 77, Rochester Row, London, S.W.l. ROLLS-CAYDON, LTD., are featuring inexpensive and medium priced receivers, all fitted with Celestion Loudspeakers, also, in addition, a six-valve Super Heterodyne suitcase receiver at a slightly higher price. Other models featured include an entirely self-contained Super Heterodyne receiver in an upright cabinet, complete with Moving Coil Loudspeaker. The cabinet is of burr walnut. This receiver may also be operated from the mains. Additionally, Rolls Caydon are featuring in their Upright Models a three-valve All Mains Receiver, complete with Moving Coil Loudspeaker for operation either from A.C. or D.C. Also, we shall be showing a Radio Gramophone driven entirely ofl batteries including the “ Neverwynd gramophone motor which requires no handle, and is capable of running 500 records without a charge. This Radio Gramophone can also be operated from the Electric Light. Rolls Caydon Suitcase models are called the "Junior IV” “ S.4 De Luxe,” and “ Phantom Regional.” The Upright and All Mains Models are numbered 101-107. “The Wireless World.” “The Wireless Engineer & Experimental Wireless.” Iliffe & Sons, Ltd., Dorset House, Tudor Street, London, E.C.4. Telephone : City 2847 (13 lines). Telegrams : " Ethaworld Fleet, London.” “ Experiwyr Fleet, London.” “ THE WIRELESS WORLD,” published every Wednesday, Price Fourpence. The Paper for Every Wireless Amateur. " THE WIRELESS ENGINEER & EXPERIMENTAL WIRELESS,” published Monthly, Price Two Shillings and Sixpence net. The journal of Radio Research and Progress. " THE WIRELESS WORLD ” DIARY for 1932. Containing useful facts and figures for wireless users with ample space for personal notes and memoranda. Is. Gd. net. A Selection of Wireless Books including " Radio Data Charts,” by R. T. Beatty, M.A., D.Sc. ; “ The Elementary Principles of Wireless Telegraphy and Telephony,” by R. D. Bangav and O. F. Brown, B.Sc. ; “ The Handbook of Technical Instruction for Wireless Telegraphists,” by H. M. Dowsett, M.I.E.E. ; “ Wireless Direction Finding,” by R. Keen, B.Eng.(Hons.). 119 DON'T MISS /• STAND No and the “ SQUARE PEAK” lli'(ill. Trade Marl:. SETS and COMPONENTS demonstration room D 21 Advertisement of Oliver Pell Control, Ltd., Klnpsmiji House, 10-3, Kingsicay, London, W.C.9. Telephone : IIolborn 6303. 120 Stand. No. Empire Hall, Ground Floor. Memoranda. CQ Varley (Proprietors: Oliver Pell Control, Ltd.) Kingsway House, 103, Kingsway, London, W.C.2. AN ENTIRELY NEW RANGE OI' ALL-ELECTRIC RE CEIVERS AND RADIO-GRAMOPHONES FOR A.C. or D.C. Mains and embodying the Square Peak principle. The Receivers include 3 and 4 Valve Models, all with built-in Moving-Coil Speakers. THE CONSTANT SQUARE PEAK COIL, which gives a constant square-topped peak and separation of substantially 9 kilocycles over both wavebands, and other Tuning Coils. A RANGE OF NICKEL-IRON L.F. INTERVALVE TRANS FORMERS AND CHOKES. PUSH-PULL INPUT AND OUTPUT TRANSFORMERS, in an extensive range. WIRE-WOUND RESISTANCES AND POTENTIOMETERS OF ALL TYPES. NEW GRAMOPHONE ARM AND PICK-UP. A NEW RANGE OF MAINS TRANSFORMERS AND CHOKES. THERMAL DELAY SWITCH AND SPECIAL MAINS TRANSFORMERS FOR USE WITH THE OS RAM G.U.l RECTIFIER. Also H.F. Chokes, R.C. Couplers, Output Transformers and Chokes, etc., etc. 121 STOP AT CAMCO’S STAND 51 (GROUND FLOOR, EMPIRE HALL) FOR RADIO CABINETS OF EVERY DESCRIPTION IN OAK, MAHOGANY and WALNUT See the “ Windsor” Cabinet as illustrated, only 75/- and the specified cabinet for the V3 Kit. Also the very latest designs in Radio-Gramophones, Midgets, etc. THE NEW “WINDSOR” CARRINGTON MFG. CO. LTD., CABINET 24, Hatton Gdn., London, E.C.1. I ’Phone : HOL. 8202. Works : 5. Croydon. RADIO MANUFACTURERS & OTHERS— ATTENTION! Cl, You need Wood Wool for your packing. CL We can meet your requirements whether large or small. CL Stocks of various grades at over 100 Depots through out the United Kingdom. CL Weekly or monthly contracts at lowest current prices. Prompt Service. Guaranteed Quality. Samples on request. JOHN G. ABBOTT LIMITED, LONDON : LIVERPOOL {Read. Office): 103, Pancras Rd., N.W.l “The” Wood Wool People 31-33, Vauxhaii Road. Tel. North 4812. Tel. Bank 3400. 122 Stand No. Empire Hall, Ground Floor. Memoranda. JTQ Murphy Radio Ltd., ^ ^ Broadwater Road, Welwyn Garden City, Herts. THE MURPHY TYPE B-4 PORTABLE RECEIVER. SPECIFICATION : 4 Valve screen grid circuit incorporating ganged circuits and single tuning control, with reaction. Calibration direct in wave-lengths. Special acid-proof battery rack. Separate withdrawable chassis. Complete screening. Specially selected polished walnut cabinet, with concealed handgrips in base. A Ball-Bearing Turntable is incorporated. Total Weight, including H.T. and L.T. Batteries, 32 lbs. approximately. Selectivity is of a very high standard—at the very gates of Brookman’s Park the twin transmissions can be tuned out and foreign stations brought in at full strength. Particular attention has been paid to quality of reproduction, and performance is fully guaranteed. THE MURPPIY TYPE A-3 ALL-MAINS RECEIVER. SPECIFICATION : 3-valve All Mains Receiver, with self-contained energised field Moving Coil Speaker. Screen Grid Detector and Pentode Valves with Valve Rectifier. Selectivity; ample selectivity is provided by employing a band pass filter in front of the H.F. valve, and a tuned grid circuit output from it. Single Tuning Control marked in wavelengths. The Cabinet is in best quality walnut of pleasing and original design. The Pentode Valve gives 1,500 milliwatts undistorted output. Particular attention has been paid to quality of reproduction, and performance is fully guaranteed. 123 formo-densor l'6 MID LOGnJP RANGE VARIABLE CONDENSER of *'0' QUALITY COMPONENTS ONI STAND NO 61 Don’t fail to see these new Components embodying entirely new Formo features. ALWAYS CHOOSE By* 7-^3? FORMO FOR U EFFICIENCY. I mi. SLOW MOTION CONDENSER PRICE TRIPLE GANG or CONDENSER < (Completely Screened). I The right hand knob controls 1 all rotor vanes and the left hand one the stators of .the two left hand condensers. The position of the stators is indicated by a shadow thrown on_ the drum by a hidden pointer. Can be made up in Is several arrangements. Rigid m M cast aluminium housing. I PRICE 3 oh t | AO 9.0, ARTHUR PREEN ACOI? GOLDEN SQUARE I LONDON • W1 FACTORY! CROWN W0W5 SOUTHAMPTON % o' CAp -2 3f5 VERNIER „cy MAINS CONPEN5ER DIAL 124 Stand No. Empire TTall, Cl round Floor. Memoranda. fS\ Wingrove & Rogers, Ltd. 188-9, Strand, London, W.C.2. VARIABLE CONDENSERS OE ALL TYPES. 1. East and Slow Motion Types. 2. Ganged Types on Die-Cast Frames. 3. Differential Balancing and Reaction Types. 4. Special Short Wave Types. 5. Disc and Drum Drives, Escutcheons, Couplers, Knobs and Dials. - I /Cl Arthur Preen & Co., Ltd. (Formo Co.), Golden Square, Piccadilly Circus, London, W.l. Crown Works, Regent Park, Southampton. This exhibit includes the whole range of the Formo Company's j Products. New lines of particular interest are as follows :— The New Formo Extensor Condenser. The New Slow Motion Condenser. Formo Mains Condensers in Metal Boxes. A new Dual Gang Condenser with illuminated dial and special shadow indication showing the position of the moving plates. | A new 3 Gang Condenser with separate screening. A range of P.W. Coils covering every P.W. coil specification. Special set of Super-Het Coils. 12a J m i V —— SEE STAND No. 62 FOR ALL THE LATEST ) TYPES OF VARIABLE } CONDENSERS & DIALS. PRECISION 1 Advertisement of Jackson Bros., 72, St. Thomas St., London, S.E. I. INSIMIMENIS i 120 Stand No. Empire Hall, Ground Floor. Memoranda. fi/} Jackson Brothers, i 72, St. Thomas St., London Bridge, S.E.l. ! Here, as usual, is shown a varied selection of Variable Air spaced Dielectric Condensers. The types include those 1 ' suitable for every purpose, viz., S.L.F. Log, Short Wave, ' Neutralising, Differential, Midget Reaction, and Universal Log. The New Models include, The Extensor, Enclosed Gang, Base Board Trimmer, Base Board Drum Dial, Popular Model, III Vernier Dial, Illuminated Drum Dials, Tiny Slow Motion, and Chassimount Gangs, etc. /C7 Tannoy Products Dalton Street, West Norwood, S.E. 27. TANNOY Mains Units for H.T. TANNOY Mains Units for H.T. and L.T. TANNOY Mains Units for H.T. and L.T. and incorporating independent G.B. TANNOY “ All Electric ” Midget Receivers. TANNOY " All Electric ” RADIOGRAMS. TANNOY Power Amplifying Equipment. ! /yl Sovereign Products, Limited, ^ " 52 & 54, Rosebery Avenue, London, E.C. 1. Compression Condensers, Spaghetti Resistances, Volume Controls, Dual Range and Screened Grid Coils, L.F. Transformers, L.F. Chokes, Output Transformers, Fixed Condensers, Grid Leaks, Wave Traps, Coil Quoit Formers, " Popular Wireless ” Coils, Variable High Resistances, Wire Wound Resistances, Push Pull Switches, Transportable Sets, Loud Speakers, Wall Plugs and Sockets, Terminal Mounts, Potentiometers, Rheostats, Plug-in Coils, Six-pin Bases, Potential Dividers, H.F. Chokes, Binocular Chokes, Tubular Chokes, “ Daily Mail ” Station Selectors, “ Daily Herald” Wave Filter, Sovereign Selector Unit, Selector Tuners. 127 Follow the Crowd to STAND 65 or DEMONSTRATi©M ROOM D22 See and hear the latest I «• *. s: TRADE 7AARK \ Hr,III. .Vos. 515GS.'/ «t- 51UISO. PRODUCTIONS IN i LOUDSPEAKER UNITS LOUDSPEAKERS k PICK-UP RECEIVING APPARATUS : Make the Blue Spot Stand your first visit. THE BRITI/H BLUE /TCI CCMPANY LTD 3LUE SPOT HOUSE • 94/96 ROSOMAN STREET - ROSEBERY AVENUE • LONDON * E CI 128 Stand No. Empire Hall, Ground Floor. Memoranda. AC The British Blue Spot Company, Ltd., Blue Spot House, 94/96, Rosoman Street, E.C.l. Loudspeaker Units and Chassis. Inductor Type Unit with Chassis. ! Complete Loud Speakers. Mains Disturbance Eliminators. Rejector Wave Trap. Permanent Magnet Loud Speaker with Transformer. Moving Coil D.C. Energised Model with Transformer. All Mains Receivers. AA Oldham & Son, Ltd •J Denton, Manchester. L.T. ACCUMULATORS. C.L. types ; a range of six sizes in celluloid cases with inter-leaved plates, litted with separators, varying in capacity from 13 to 80 amp. hours. C.L.C. types ; a range of five sizes in glass containers, made up with inter-leaved plates, fitted with separators, varying in capacity from 26 to 80 amp. hours. Fitted with free metal carriers. SLOW DISCHARGE types; 0.25, 0.50 and 0.75, having capacities of 25, 50 and 75 amp. hours respectively at the slow discharge rate. Each cell fitted with 2 central positive plates £ in. thick, and 2 negative plates also $ in. thick, arranged one on each side of the positive group. The special feature is that although these cells are designed for slow discharge work, they may be recharged quickly. They also are fitted with a free metal carrier. UNSPILLABLE types ; A range of 16 types of Unspillable accumulators for Portable receivers, fitted with jelly and i free electrolyte. H.T. ACCUMULATORS. Two sizes of H.T. accumulators, types H.T. and L.H.T. which have capacities of 2,750 and 5,500 milli-amps, respectively. Also containing crates for assembling in ‘ Expanding Bookcase ’ formation. H.T. BATTERIES. A new range of Dry batteries for H.T. and grid bias, in 8 voltages as follows ; 9, 16£ for G.B., 66, 99, 108, 120 volts standard capacity H.T., 64, 120 volts triple capacity. A collection of plates, groups, accumulator containers, terminals, etc. ' 129 BRITAIN'S' Britain’s leading Leading r V ©33 Radio mfiffisaEsj mm^k^THREEVALVBR m Journals V- M ait. daouj "SlMPUc SUPERCITY" «; '-I mil ' •fN» »u.„e / 1 "ssh*-1 itucn/ir, ^-0*3* SI SEE THEM AT STAND \m>wgfm No. 67 Empire Hall j i : \J t K UKKCNj V RAfXOCOMSULTAMT-IN CHIEF CAPT.P.PECKER5LEV M.IE.E AMJg.^iSET/ Hr...... e ' S28SW The really practical paper for -MS Amateurs and Experts. : & Famous for the lucidity of the iVrHis technical articles and the detail moorside','eo'gT^%ar -<5vissue and accuracy of the instructions given for the home constructors. it «»?• 9tsi ion lOou m* p X A7ote /o Advertisers. Advertisement Rates and full particulars of these three journals can be obtained at the Stand or from JOHN H. LILE Ltd. Phone: 4 LUDGATE CIRCUS LONDON E.C.4. CITY 7261 130 Stand No. Empire Hall, Ground Floor. Memoranda. /C7 The Amalgamated Press, Limited, ^" The Fleetway House, Farringdon Street, E.C.4. On Stand No. 67, Empire Hall, the very latest in radio receivers for home constructors will be exhibited and experts will be in attendance to advise on all wireless matters. The staff of experts connected with “ POPULAR WIRELESS," “ WIRELESS CONSTRUCTOR " and “ MODERN WIRE LESS are all men of wide practical experience and are daily confronted with some of the great perplexities of this new science. If you have a problem which defies solution, one of these experts will be pleased to assist you. These three journals are renowned for the accuracy and lucidity of the technical articles and diagrams for home constructors. Many of the most widely used and satisfactory receivers to-day have been built from the instructions given in " POPULAR WIRELESS." “ WIRELESS CONSTRUCTOR " is a Gd. monthly which caters especially for the experimenter. Many of the develop ments now in general practice are due to the enterprise of this up-to-date journal. “ MODERN WIRELESS " is the magazine de luxe among wireless journals and at Is. monthly is very good value. It is full of exclusive information on all developments in the radio world and specialises on long distance and other up-to-date receivers. There is something of interest and value for every wireless amateur and expert in these famous periodicals. Advertisers , of wireless components, etc. are specially invited to look ■ through the journals exhibited on the Amalgamated Press Stand. They are recognised as the best “ pullers " on the market. AC F. G. Heayberd & Co., 10, Finsbury Street, London, E.C.2. Heayberd Mains Units (Complete). Assembled Kits of Parts which require wiring-up only. All Electric Units. /CQ Priestly & Ford, 3-11, Carrs Lane, Birmingham. THE WHOLESALERS: Are showing representative ranges of Receivers, Radiograms, Speakers and components by all the best manufacturers, for whom they are main distributors. B.T.H., Celestion, Cossor, Colvern, Ekco, G.E.C., J.B., Marconiphone, Milliard, Ormond, Pye, Ultra, etc. Complete ranges of newest com ponents for the trade. 131 I STAND No. THE SHOW OF SHOWS I 208 SLEKTUN 3-Valve (registered trade mark)I RECEIVER Rich in Value, Volume & Tone Here is the greatest triumph of the British radio industry—a completely self-contained 3-valve Receiver, with Amplion Loudspeaker, English Valves, Exide Accumulator, Silver- town H.T. Battery, and best all- British components. It gives you high-priced radio performance at. an exceptionally low initial price and negligible maintenance cost, H.T. current consumption is lower than any other portable on the market. Ccmpletewith Valves. liatteries & Speaker 85* No Extras Height: IS inches Width : 13 inches Depth : 7J inches The SLEKTUN (registered traoe mark) L.F. TRANSFORMER This new L.F. Transformer is a real advance on anything hitherto achieved in transformer design. It is made under a patented process by which short-circuited turns are rendered impossible, and a rich and generous volume produced with complete absence of distortion, harsh background or static noises of any kind. It is a high grade Transformer of exceptionally high primary induct ance. It is with Size Overall: Jl" wide, 2" high out equal for 2" deep. quality and de pendability. 7*6 Enquiries invited from Set Manufacturers RATIOS 2:1 4:1. for this super transformer, without case, cn exceptionally favourable terms. Stand No. 208 Empire Hall, First Floor aw~w SLEKTUN PRODUCTS LTD. 21, Douglas Street, Vauxhall Bridge Road, London, S.W. I. Telephone: Victoria 3406 132 Stand No. Empire TTall, Ground Floor. Memoranda. 7A The “Danipad” Rubber Co., Ltd., " ” 5-7, Market Street, Finsbury, London, E.C. 2. Ebonite, in all grades and finishes. Panels, drilled, engraved and slotted. Cut-sections of Ebonite, Rods, Tubes, etc. Coil Formers, Ribbed and Plain. Choke Formers, Plain or Slotted. Terminal Plugs, drilled and engraved. Con densers, Balancing, Neutralising, Reaction, .Square Law, Mid log line, S.L.F. Differential, Midget. Chokes, .Single, Binocular, Portable, Barrel. Bakelized Formers, Dexolin. Switches, Push Pull, Three Point, Rotary, Lever, S.P.D.T. Valve Holders, 4-pin, 5-pin semi fixed, 4-pin fixed. Grid Leak clips and Anode Resistance clips. Coils, Melody Maker, New Type Cossor, Master 3, Dual Range, Short wave, Manufacturers lines, Variometers. Aerial Equipment, Lightning Switch and Lead-in-Tube combined, Lead-in- Tubes, Insulators, Portable aerials. Transformers, L.F., Shrouded and Bakelite covered. Wall Plugs and Sockets, Cone Chassis, Loud Speakers and extension boards. Coil Holders, 2 and 3 way geared, D.X., Quick Action, Back of Panel, Basket, Coil mounts, wedge plugs. Dials, 3 in. and 4 in. all colours, Midget slow motion dials. Knobs, all sizes and colours, pointer and arrow. Wireless Receivers, 2 and 3 Valve, Mains and Battery operated. 5 Valve Portables and Transportables. 4 Valve all Electric Radiogram, A.C. or D.C. 71 Bernard Jones Publications, Ltd. ■ 58/61, Fetter Lane, London, E.C. 4. " AMATEUR WIRELESS ” contains, every Thursday, many articles, written by experts, with the object of helping every set-user to get the best possible reception from his Receiver and accessories. Some of the most successful sets in use to-day have been described in the pages of “ Amateur Wireless,” and the home-constructor will find, in each issue, full working instructions, lay-outs and diagrams for making, easily and inexpensively, reliable and tested sets. On Sale, weekly, 3d. “WIRELESS MAGAZINE,” the sponsor of the famous “ Super GO ” and other well-known Receivers, describes in each number several efficient sets, which can be made at home without the least difficulty. The other regular contents include :—Buyers’ Guide to Sets, in which new Receivers are reviewed as they come on the market—Tests of new apparatus—Criticisms of the Best Gramophone Records— Topical articles always readable and of value to everyone interested in radio. On sale about the 23rd of each month, Is. 133 Suppliers to the leading manufacturers WIRES for WIRELESS. Concordia electric wire co., ltd., Trent mills New Sawley Nr. NOTTINGHAM. BUY BRITISH ENTIRELY THIS YEAR THREE ’S VALVE PORTABLECRAUFURD 5 YEARS AHEAD IN DESIGN RESULT OF 25 YEARS RESEARCH X TNDOUBTEDLY the most interesting set in the show. For a three valve transportable the results IlilPfe are astounding. The secret is the use of the * Craufurd Acceptor.’ By means of this device, wire less transmissions arc received via the earth, instead of the usual unsightly aerial. Gives results with three valves equal to any 5 valve set. The ‘ Acceptor ’ is incorporated in all Craufurd sets, being the patent of Captain Craufurd, R.N., who gave the first broadcast in English waters in 1907. These sets are the outcome of 25 years experience and research by Capl. Craufurd, who is technical adviser to the Company. The 3 valve model is housed in a beautiful oak cabinet, with built in n loud speaker. .The tone, range and selectivity of this set is well above those costing double the price. All Ilritish make. Valves, batteries, etc., arc included. A 5 valve model in mahogany is also produced, the price being £11 11s. Od. A deposit for either model can lie paid at the stand. During the exhibition, the Craufurd Acceptor will be on sale at the Stand, and for the sum of 2/6 you can give your set that extra power that £6/15/ will bring in that elusive foreigner. OR 12/6 DOWN AND CRAUFURD WIRELESS 11 PAYMENT8 OF 12/6. 24-26, HIGH HOLBORN, LONDON, W.C.l YOU MUST SEE THIS SET AT STAND NO. 242 134 Stand No. Empire Hall, Ground Floor. Memoranda. 70 Grosvenor Electric Batteries, Ltd., ■ 2«3, White St., Moorgate, London, E.C. 2. Manufacturers of every description of Dry Cell Batteries for Wireless, Bells and Telephones, Medical Apparatus, Acoustic Instruments, and Flashlights and Torches. SPECIALITIES : “ GROSVENOR MERCURY ” BATTERIES for Portable receivers. 4 4 GROSVENOR MERCURY ” BATTERIES for Wireless. “GROSVENOR TURNLIGHT ” Pocket Lamps and re fill Batteries. 77 Umello Ltd., ■ ^ 55, Great Marlborough Street, W.l. All Mains Receivers in Walnut and Mahogany Cabinets incorporating moving coil loudspeaker of latest design. All sets are self-contained and guaranteed for twelve months. Types, 3-valve and 5-valve. Single knob control. Long and medium wavelengths. Gramophone pick-up attachment. Plug for additional loudspeaker. 135 THE PATH TO PERFECTION AND SIMPLICITY Why employ dozens of switches in your set when THE VALUNDA simplifies matters ? Perfect in design, simple to fix and connect, it can be used either to switch on your filament or to change over from one circuit to another, It will, if desired, operate the two at the same time. Of neat appearance, good workmanship, self-cleaning, it never fails to ensure good connections. CARRY YOUR ACCUMULATOR IN COMFORT without soiling your garments or hands with that destructive acid. i SEE THE NEW WAY AT STAND NO. 224 THE EASY TO FIX STRAP. m HilA Jlddrcss enquiries to :— //. //////// f//// '•* EV///////////W////A VALUNDA SWITCHES, 28, BLOMFIELD ROAD, LONDON, W.9. STAND NO. 195. 1st Floor. EMPIRE HALL. GAMAGES-HOLBORN SEASON 193 I-1932. YOU MUST SEE OUR 2 AND 3 VALVE RECEIVERS WITH SELF-CONTAINED SPEAKER. All Batteries fitted in Polished Oak Cabinet. These Sets incorporate all the main essentials which make for purity of tone, selectivity, volume and long service. Size 15 ins. x 123 ins, x7$ ins. 2 Valve Receiver. THE "COMPACT” 2 Valve Receiver complete with Marconi-Osram Valves, High Tension Battery, Accumulator, Grid Bias Battery and self-contained Cone Speaker. Cash Price £3 19 6 or 12 monthly payments of 7/6. 3 Valve Receiver. THE "COMPACT” 3 Valve Receiver. Cash Price £5 lO O THE "COMPACT." or 12 monthly payments of 10/-. GAMAGES-Holborn, E.C.i. ’Phone: Holborn 8484. Also at 107. CHEAPSIOE. 136 Stand No. PAirmn Hall. Ground Floor. Memoranda. VA Siemens Electric Lamps and ' Supplies Limited. 38-39, Upper Thames Street, London, E.C.4, and at Belfast, Birmingham, Bristol, Cardiff, Dublin, Glasgow, Leeds, Liverpool, Manchester, Newcastle-on-Tyne, Nottingham, Sheffield and Southampton. ' SIEMENS I'UIJ, O’POWER RADIO BATTERIES. Vertical Pattern. Popular Type. Power Type. Super-Radio Type. Horizontal Pattern. Special Type for Portable Sets. GRID BIAS BATTERIES. : SIEMENS DRY AND INERT CELLS AND BATTERIES FOR L.T. AND GENERAL PURPOSES. . L.T. ACCUMULATORS (GLASS CELL TYPE). RADIO TESTING INSTRUMENT. SIEMENS " NEOPHONE ” PRIVATE AUTOMATIC TELEPHONE EXCHANGE FOR 10 LINES. WITH TRANSRECTER. 137 ? RECEIVERS mi SPEAKERS M si AMPLIO i STAND No 75. MPIR HALL ON RIGHT OF MAIN STAIRCASE ALSO AT AMPLION HOUSE 9 MACLISE ROAD CLOSE TO OLYMPIA GRAHAM AMPLION LTD. 26, SAVILE ROW, W I WORKS, SLOUGH, BUCKS. 138 Stand No. Empire Hall, Ground Floor. Memoranda. 7C Graham Amplion Limited. ■ ^ St. Andrew's Works, Slough, Bucks. Sales OHices and Showrooms, London: 26, Savile Row, W.l. Manchester: 10, Dolefield, Bridge Street. Agencies and Representatives throughout the World. AMPLION RADIO—AMPLION’S latest Receiver—a 6-valve Set, mains driven, complete with Moving-Coil Speaker, will be a model which will be one of the outstanding exhibits at this year’s Show. The newly introduced A.C. Transportable Receiver will also be shown, available either with Moving Coil or Balanced Arma ture Speaker. This model is capable of really remarkable reproduction, and will prove a most attractive model to those who are definitely requiring a completely self-contained Set, giving good Moving Coil reproduction. The 2-valve A.C. Receiver completes the range of Mains- operated AMPLION Sets. In the battery class, there will be the popular Suitcase and Cabinet Portable Sets, which have proved themselves capable of such a very excellent performance. AMPLION SPEAKERS.—The full AMPLION range of Speakers for the 1931-1932 season includes many entirely new and very attractive models. As a range, it is undoubtedly more representative of every type of modern design and im provement than ever before, comprising twenty speakers at prices which afford as much variation as the models them selves. The AMPLION “ Popular Range,” consisting of three models, ! and Open Cone (Type A.C.2.A) superseding the “ Guinea ” i Cone, a Cabinet Cone (Type A.C.6) superseding the “ Two Guinea ” Cone, and a Balanced Armature Cone (Type A.B.4), ■ have already established themselves in public favour. The Senior Balanced Armature Cabinet Speakers (Type A.B.41), which aroused so much interest at the Radio Show of 1930, will again be displayed. I MOVING COILS.—This year, AMPLION for the first time include Moving-Coil Speakers in their range. In this class, will be shown two Units, both of the Permanent Magnet Type (M.C.6 and M.C.9). Each may be purchased as a com plete Unit unmounted, the M.C.6 in this form having a universal transformer fitted. i These Permanent Magnet Units will also be displayed housed in attractive cabinets of alternative finish, all complete with transformers. An Energised D.C. Moving Coil (Type E.M.644), sold as a Unit or fitted with universal transformer, but not in cabinet form, i concludes the AMPLION Moving-Coil series. In addition, Cone Assembles comprising a Balanced Armature Unit, and the famous “ Lion ” Speaker in table cabinets, and chassis, will also be on show. Demonstrations will be given daily at AMPLION House, No. 9, Maclise Road, just at the back of the Exhibition, where all models may be heard working under normal conditions on : direct Broadcast. Please ask for invitation card. i 131) and see the CLIX CONSTRUCTOR’S KIT CLIX CONSTRUCTOR’S KIT for all set builders Saves Time and Money Contains nineteen specially selected fitments which are Contents value 3/5 essential for every set built COMPLETE KIT GET YOUR KIT AT STAND LECTRO LINX LTD. 254, Vauxhall Bridge Rd., London, S.W.l. 202 EMPIRE HALL. FOR ANY KIND OF CLEANING get in touch with the GENERAL WINDOW CLEANING CO. Official Stand Cleaners to this Exhibition. PARQUET FLOOR POLISHING CARPET CLEANING VACUUM CLEANING WINDOW CLEANING CHIMNEY SWEEPING CHARING &. GENERAL CLEANING, Etc. Reliable Women or Men Cleaners supplied by the Hour, Day or Week. TERMS MODERATE. ESTIMATES FREE. ALL ORDERS PROMPTLY ATTENDED TO. Phone or Write for a representative to call and give free Estimate. PADD. 8530. MUSEUM 9068. 6, Avery Row, Bond St., W.l 71, Newman St., Oxford St., W.l. LET US QUOTE FOR YOUR WINDOW CLEANING. All our staff are fully covered by Insurance for Workmen’s Compensation and Third Party risks HO Stand No. Empire Hall, Ground Floor. Memoranda. 7{C The Ever Ready Co. (Gt. Britain) Ltd. I * ^ Hercules Place, Holloway, London, N. 7. ELECTRIC CELLS AND BATTERIES of all types for High and Low Tension current supply and Grid Bias for Wireless receiving and transmitting sets, sound apparatus, public address equipment, etc. I PRIMARY dry and inert Cells and Batteries. SECONDARY storage cells and accumulators. Celluloid cased types (free acid). Celluloid cased types (unspillable). Celluloid cased types (jelly acid). Glass cell types (free acid). Ebonite cased types (unspillable). 77 Osram Valves. The General Electric Co., Ltd., Magnet House, Kingsway, W.C. 2. THE OSRAM FOUR (NEW MUSIC MAGNET) The 1031 model of the well-known Osram Music Magnet Construction in Kit which has two stages of screen grid ampli fication operated by only one tuning control. The Osram Four covers both medium and long wave Broadcast bands by the operation of one external switch. Terminals are now fitted so that a Gramophone pickup can be employed and the kit is supplied with a solid Walnut cabinet of modern design with front panel to match. By the addition of the GECoPHONE A.C. CONVERSION KIT, the Osram P'our can also be operated entirely from A.C. Mains. ALL TYPES OF OSRAM VALVES. Indirectly heated A.C. Mains Valves. Indirectly heated D.C. Mains Valves. Pentodes for Battery operated Sets. Special Pentodes for A.C. Mains operation. Super-Power Valves. New types of Rectifiers for A.C. Mains Sets and Eliminators including Mercury Vapour (Hot Cathode) Rectifiers. All types of Valves for portable and other battery driven sets. New Screen grid valves. DEMONSTRATION OF CONSTRUCTION OF THE OSRAM FOUR (NEW MUSIC MAGNET). A complete range of Gecophone Radio Apparatus and Osram Valves may also be seen on Stand No. 24 in the National Hall. 141 Modem radio reception calls for amplification with the least possible distortion throughout the musical scale. It is also necessary that components should occupy as little space as possible. For efficiency of this kind use L.F. transformers with cores of RADIOMETAL or MUMETAL —the Magnetic Alloys of High Performance and established reputation. Manufactured by The GUTTA PERCHA COMPANY Branch of Telegraph Construction & Maintenance Co., Ltd. I WHARF ROAD, CITY ROAD f LONDON, N.l. Established 1864. 'Phone: Clerkenwel' 6031. TUNEWELL See Stand 82, Empire Hall, for New and Complete Range of Eliminators and Component Parts. ALSO THE NEW ULTRA SELECTIVE DUAL COILS. SPEAKERS, UNITS, ULTRA SHORT AND TWO PIN COILS, H.F. CHOKES, RESISTANCES, STANDARD DUALS, Etc., Etc. TURNER & CO., 54, Station Rd., New Southgate, London, N. 11. 142 Stand No. Empire Hall, Ground Floor. Memoranda. 70 J. Dyson & Co. (Works), Ltd., ^ 5, Godwin Street, Bradford, Yorks. “ GODWINEX ” Mains Units for D.C. and A.C. Mains, includ ing Grid Bias Units, Trickle Chargers, Rectifiers, etc. “ GODWINEX ” Valveholders. “ GODWINEX ” Mains Transformers and Smoothing Chokes. " GODWINEX ” Super Non-Corrosive Earth Tubes. “ MICROTUNE ” All-Mains Chassis for A.C. Mains. “ AIRMAX ” Coils, H.F. Chokes, etc. 70 Rooke Bros., Ltd., ■ S Queensway, Ponders End, Middx. Transformers, Speaker Units, Pick-ups, Volume Controls, Tuning Coils, Switches, Pre-set Condensers, Resistance Links, Plug-in Coils, Coil Holders, Chokes, All-Electric Radio- Grams and Receiving Sets. OO Radio for the Million, 63, Lincoln's Inn Fields, London, W.C.2. Copies of “ Radio for the Million " will be on sale with full instructions in assembling and working the new “ Radio for the Million " Kit Set V. 3, backed by nine leading manu facturers who have combined to produce it. Complete chassis and some of the specified cabinets will be shown. Cl The Gripso Co. 32, Victoria Street, London, S.W. 1. “ GRIPSO ” Plugs and Sockets. “ GRIPSO ” Indicating Switches. “ GRIPSO ” Tag Ends. ' “ GRIPSO " Earth Clips. “ GRIPSO ” Batterv Clips. “ GRIPSO ” Wander Plugs. “ GRIPSO ” Labels. CO Turner & Co., 54, Station Road, New Southgate, N.ll. TUNEWELL. Complete A.C. and D.C. Eliminators, Transformers, Chokes, etc. Tuning Coils of all types. Speakers and Units. Resistances, H.F. Chokes, etc. 14:* i t SEE THEM ON STAND No. 83. THE •• OER^I i f i Range Cover ; of Every : I Radio Class ( Receivers ® of Trade ■ < Quality Supreme : FROM THE MOST COMPETITIVE TO THE MOST EXCLUSIVE, S Ask for details of the NEW “ SELECTOR ” SUPER-HET TABLE MODEL. ■: SELECTORS (1931) LTD. 180/182, ALBION ROAD, STOKE NEWINGTON, N.16. Telephones: CLISSOLD 2891/2/3. Telegrams : “ ELEGASLITE. STOKE.” 1 i ? r? i J Manufacturers of Accumulators i. with over 50 years experience for WIRELESS •y RADIOGRAMS i SOUND EQUIPMENT STARTING & LIGHTING s YACHT LIGHTING i HOUSE LIGHTING > MEDICAL I STAND No. 249 i (EMPIRE HALL) ■ LITHANODE CO., LTD., 190 Queen’s Road, Battersea, S.W.8. ; Telegraphic Address : Telephone : ' “ Lithanode, Battpark, London.” Macaulay 4541 /2. 144 Stand No. E.mimrio Ham., Ground Floor. Memoranda. CQ Selectors (1931) Ltd. 180/182, Albion Rd., Stoke Newington, London, N. 16. < I Servis ” Table and Portable Receivers, all types and new Models. “ Selector ” New Super-Het. Table Model. “ Selector ” Radio-Gramophones, All-Rlectric Receivers and Portables. Qd. Harlie Bros., (Edmonton), Ltd. 1 Balham Road, Lower Edmonton, N. 9. This year Harlie Bros, display a complete range of Electric Gramophone Pick-ups from simple construction to elaborate de luxe model possessing Ball Bearing and Spring Com pensating Movement. All models supplied with and without Tone Arm and Volume Control. Finish in Bakelite and metal; the new de luxe Model all Bakelite. The Harlie Tone Selector, connecting to existing Loud Speakers, produces five different tonal reproductions. A new article, the Harlie Microphone, is supplied in a complete assembly outfit, in ! cluding transformer and battery with “ On ” and “ Off ” ( switch. An interesting booklet entitled “ Revealing the Hidden Beauty in your Gramophone Records,” is supplied free upon request, describing how to get the best results from the Electric Gramophone Pick-up in conjunction with existing Radio Sets. QC Houghtons the Wholesalers (Ensign, Ltd.), 88-89, High Holborn, London, W.C.l. Every Radio Dealer who visits the Show will be interested in Houghton's Stand. It is built specially for him. Here the dealer will find a complete display of the principal British-made Receiving Sets, Portables, Radio Gramophones, Loud Speakers and Accessories—the epitome of Olympia. The choice of experienced buyers. A safe guide to what will sell during the coming season. The task of deciding stock made easy. Dealers can place their orders at Houghton's Stand for almost every line at the Show. One order, one account, one pay ment—saves time, trouble, money. . Mf> p i HUSTLER, SIMPSON STAND & WEBB, LTD•J STAND 317, Hoe St., Walthamstow, E.17. 86 86 'Phone: Walthamstow 5535-6-7. (Private Exchange.) SUPER TWO 1932 Model. COMPLETE with Valves, Speaker, Accumulator, and Batteries in Oak Cabinet. £4:4:0 SELF CONTAINED TRANSPORTABLE 3 VALVE RADIO-GRAM. BRITISH & BEST Inclusive price £16 : 16 : 0 Complete with Valves, 4 Pole balanced armature L.S. Unit, 120 Volt Super Capacity H.T. Battery — Grid Bias Battery, improved Sparta 7 Plate, 60 A.H. Accumulator — Garrard Double Spring Motor and A.E.D. Pick-up in beautiful Walnut Console Cabinet. 11G I Stand No. Empire Hall, Ground Floor. Memoranda. Q/C Hustler, Simpson & Webb, Ltd., 55-57, Tanner Street, S.E.l, and 317, Hoe Street, Walthamstow, E.17. 1. SUPER TWO Valve Set in Oak Cabinet, complete with Valves, Loud Speaker, Accumulator and Batteries. 2. 3-valve Radiogram in Walnut Console Cabinet, complete with Loud Speaker, Accumulator and Batteries. The Radio panel includes disc drive tuning control, volume and reaction controls, and special switch for On-Off, wave change and radiogram. In the Gramophone section is incorporated Garrard double- spring motor and an AED Pick-up. Q7 Falk, Stadelmann & Co., Ltd., ^ " 83/93, Farringdon Road, London, E.C.l i KEESCAPHONE Receiving Sets, including Straight and Screen-Grid Circuits, Self-contained Portable Receivers, in cluding Local Station and Screen-Grid Long Range Models. EFESCA High Tension Eliminators for A.C. and D.C. PURAVOX Loud Speakers and Loud Speaker Units. EFESCA Components. EFESCA High Tension and Grid Bias Batteries. L.E.S. Distributors, Ltd., 88 9, St. Martin’s Street, Leicester Square, W.C. 2. As in previous years, this exhibit is designed to appeal only to the Trader, who will be made very welcome, and at whose service all the firm’s resources are placed. The exhibit includes a representative range of Receivers, Speakers and Valves, Batteries, etc., and a courteous Staff awaits the favour of a visit. 117 v2 SEE THE LATEST DEVELOPMENTS IN SCREENED CONDENSERS at At Stand 90 you will'find the very latest developments in fully-screened and’semi- screened ganged condensers. “ Utility ” ganged condensers are matched STAND with a high degree of accuracy, and their construction ensures perfect rigidity. You are invited to examine these and other examples of “ Utility ” Perfected Wireless Instruments. Come to Stand 90 before you forget! The “Utility ” range includes\the famous',''Mite”—the “ little condenser with the big performance.” Differential Condensers, Bakelitc Condensers. Micro Dials and Drum Dials. - Anti-capacity switches—snap and lever patterns. Ganged Switches, etc. And every ••Utility” instru ment is fully guaranteed. COMPONENTS —"PeAfect to the UxAt detcul" WILKINS & WRIGHT, LIMITED UTILITY WORKS, HOLYHEAD ROAD, BIRMINGHAM AGENTS—London: E. R. Morton. Ltd.. 22 Bartlett’s Buildings} Holborn Circus. E.C.l: Scottish: E. B. Hammond. 113 Vincent Street. Glasgow: Lancashire and Cheshire: J. R. Lister. 93 Old Road, Blackley. Manchester: Westmorland. Cumberland. Durham. Northumberland. Yorkshire and Derbyshire: 11. C. Rawson, Ltd., 100 London Read, Sheffield. ¥ * 148 Stand No. Empire Hall, Ground Floor. Memoranda. QQ Electric Gramophones Limited. I • ' The Quadrant, Winchmore Hill, London, N.21. " THE UNIT ” UNIVERSAL ELECTRIC GRAMOPHONE DRIVE.—A universal motor capable of running on any current of any kind down to 50 volts, or to 12 volts if required. “THE UNIT” INDUCTION ELECTRIC GRAMOPHONE DRIVE.—A high-speed induction motor of excellent starting torque and high efficiency at full speed. Available for cir cuits of 100-150 and 200-250 volts of 40-60 cycles per second. “ THE UNIT” AUTO-STOP for electric and clockwork motors “ THE UNIT ” PICK-UP AND ARM.—Developed for natural frequency response. Adjustable damping, needle tracking and arm length, reversible head, ball bearing swivel, etc. “ THE UNIT ” ASSEMBLY.—Comprising motor, pick-up, auto-stop, etc., in self-contained housing for fixing in cabinet direct without any fitting or setting. QQ Wilkins & Wright Ltd. J7\j “Utility” Works, Holyhead Road, Birmingham. “ Utility ” Anti-Capacity Change-over Switches, Knob Pattern, Anti-Capacity Change-over Switches, Lever Pattern, Anti- Capacity Change-over Switches, Ganged Pattern, Anti- Capacity Change-over Switches, Silver Contact Pattern, Snap Switch, Bakelite Switches, Ganging Rods, Standard Con densers, Air Type, Mite Condensers, Air Type, Differential Condensers, Air Type, Knob Control Drum Dial, Micro-dials, Ganged Condensers, fully and semi-screened, Bakelite Con i densers, Bakelite Differential Condensers, Universal Con denser, Extenser Condenser. QJ^ C. A. V. Batteries, Limited, Warple Way, Acton, London, W.3. RADIO ACCUMULATORS. NONSPILLABLE ACCUMULATORS FOR PORTABLE RECEIVERS are shown in sizes and capacities to meet all requirements, including many new sizes to suit popular receivers. The use of C.A.V. Jelly acid permits the elimina tion of electrolyte traps and so affords economy in both weight and dimensions. They may be used in any position for any length of time, and the plates remain covered with electrolyte. H.T. ACCUMULATORS.—A range of glass High Tension Accumulators in 10 volt units, also arranged in groups of 30 and 60 volts in portable containers. A range of High Tension Accumulators in all moulded cases are being shown. ! They are in units of 10, 30 and 60 volts and have capacities of 2,500, 5,000 and 10,000 milli-ampere hours. The H.T. 3, 4, and 5 models will be shown, these having separate air spaced glass cells. LOW TENSION ACCUMULATORS—A full range of Low Tension Accumulators is exhibited in glass, celluloid and ebonite Containers. MOULDINGS.—Synthetic Resin Mouldings of all descriptions. ROTARY TRANSFORMERS, ANODE CONVERTERS and MOTOR GENERATOR SETS, for anode and Filament supply to Power Amplifiers for Radio, Public Address, i Gramophone Reproduction, etc. 149 See the most up-to-date developments in . . . CONDENSERS AND RESISTANCES SHE SHE ft rHI ON Stand EMPIRE HALL 92 NATIONAL RADIO EXHIBITION nUBILIED CONDENSER CO. (1925) LTD. DUCON WORKS, VICTORIA ROAD, N. ACTON, LONDON, W.3. loU Stand No. Kmimki<: Mali., Ckound K1.00U. Ml3.MOU.VNnA. GO Lubilier Condenser Co. (1925) Ltd. " Ducon Works, Victoria Road, North Acton, W. 3. CONDENSERS.—Mica and Paper Dielectric Condensers for Wireless Receivers, transmission, high frequency and high tension smoothing in voltages from 400 to 150,000 volts D.C., also special types of Condensers for Laboratory use, etc. Condensers for Power Factor correction purposes. Condensers used in connection with telephone and telegraph apparatus. Electrolytic Condensers suitable for various voltages, both dry and wet types. Variable Air Condensers for receiving and transmitting apparatus, including the K.C. (kilocycle), Midget and Solid Dielectric Variable Condensers. RESISTANCES.—Dumetohm Grid Leak Resistances, Duwirohm wirewound Resistances, and new types of Dubilier metallized Resistances to suit all purposes. ANTI-INTERFERENCE DEVICES.—For use in connection with electric motors, etc., for the purpose of eliminating interference with radio reception. DUBIIJER RESISTANCE-CAPACITY COUPLING UNITS. DUBILIER H.F. CHOKES.—In four types to meet all requirements. DUBILIER WAVE-TRAPS.—Four Models to suit the various requirements. DUCON AERIAL ADAPTOR. Ql Simpson’s Electricals, Ltd. ' 11, Jewry Street, London, E.C.3. SIMPSON’S ELECTRIC TURNTABLE.—A British patented 1 Radiogram Motor, manufactured by British labour from 1 British material, which will be backed by a national adver tising campaign. Simpson’s Electric Turntable is no bigger or thicker than an ordinary turntable, yet the motive power is in the turntable 1 itself, one set of magnets being placed inside the other. 1 Utter simplicity is the keynote of this master patent, which is the invention of Mr. H. J. Heasman. One piece of flex only is needed, which is connected to the electric light ; circuit. This flex is supplied complete with plug. The turn table starts at a touch of the finger and stops in the same way. The Turntable is entirely suitable for those who wish to convert their old gramophone into a radio-gramophone, as it fits entirely above the motor board, leaving ample room beneath for valves, etc. It is mechanically and electrically silent, and has a current consumption of only 25 ma. lf.l Stand No. Umpire ITatx, Ground Floor. Memoranda. QA Standard Battery Go., ^ ■ 184-8, Shaftesbury Avenue, W.C.2. Standard Batteries of all sizes will be shown together with models of the new Wates A.D. Be Carbone Cell for Low Tension. These A.D. Cells give 6 years’ service on one carbon with average use on a 4-valve set. Rotary Converters, for converting D.C. to A.C. The well-known Star 4-pole Loud Speaker Units and Loud Speakers. Wates Double Cone Chassis in three sizes, New Wates Electrical Meters, Wates Resistances, 2 watt type and small fixed mica condensers. Wates Potential Divider. Wates Star Pick-up and Arm. Wates Automatic Gramophone Stop. Gramophone Electric Motors. QC H. Hacker & Sons, S ^ Perfecta Works, Ray Lea Road, Maidenhead, Berks. DYNATRON UNIVERSAL RADIO-GRAMOPHONES.— A range of high grade all-electric combination radio and gramophone instruments, intended to meet the requirements of the searchers for the highest ideals in the radio art. These Universal Radio-Gramophones have the unique advantage of being quickly altered for either A.C. or D.C. operation. In the event of any change in the electric light supply, it is only the work of a few seconds to change the operation of the receiver from either A.C. or D.C. DYNATRON UNIVERSAL FIVE, RADIO-GRAMOPHONE. Model U»3. Comprises a five-valve receiver of a very high order of selectivity, True Single Dial operation, Power Detection and a Push Pull output stage delivering 3 watts undistorted power to a moving-coil speaker. Completely electrically operated including gramophone turntable. Quick change over for either A.C. or D.C. mains. They are available in large console cabinets in various woods. DYNATRON UNIVERSAL JUNIOR Radio-Gramophone. Model U.31, is a new smaller instrument intended for use where space is a consideration. This model is practically identical with the larger Model U.53, but has one H.F. stage and a slightly less powerful output stage. The Universal mains operation feature, Band Filter Tuning and single dial opera tion have been retained. Q/C The Halcyon Wireless Co., Ltd., -S'J 27a, Pembridge Villas, Notting Hill Gate, W. 11. HALCYON this year are specialising in Super-heterodyne receivers in portable form, including cabinet and suitcase models. A new departure will be found in the radio-gram utilising the super-het circuit on the radio side and employing a moving-coil loud speaker. In this model HALCYON have aimed at producing a good radio-gram at a price within the reach of all. The All Mains Model of the EUROPA super-het, will, no doubt, attract considerable attention. The Cabinet models in this range are carried out in Walnut, which always fits into any furnishing scheme. In using the super-heterodyne circuit in portable receivers, an entirely new field is opened out, as many problems have to be overcome before a commercial model of this design can be marketed. 152 Stand No. Empire Hall., Ghound Floor. Memoranda. 07 The Junit Manufacturing Co., Ltd., ' * 2, Ravenscourt Square, London, W.6. JUNIT Mains Transformers to suit all types of Metal or Valve Rectifiers. JUNIT smoothing chokes. JUNIT Mains Units, Types 150/4A.C., 120 and 120/T.C. Special JUNIT Low Loss (LOLOS) and horizontal and vertical mounting valve holders. Multiple, push pull and three point switches. JUNIT Terminal Mounts. Receivers. QQ Stratton & Company, Limited (Eddystone Radio Products), Balmoral Works, Bromsgrove Street, Birmingham A full range of all Eddystone short wave receivers and apparatus is on view. The principal lines are 2, 3 and 4-valve short wave receivers for battery and mains operation, including : a special model for the worst tropical climates. The home constructor is catered for with short wave kits of 2, 3 and 4-valve instruments and a full range of components. Inductances and accessories for Transmitting purposes are also shewn. GO Benjamin Electric Ltd., ' ' Brantwood Worka, Tariff Road, Tottenham, N. 17. Clearer-tone Valve Holders. Vibrolders (Self-aligning Contact Holders). 5-pin Valve Holders, anti-microphonic. Double-pole, Double-throw Rotary Switch. Rotary “ on-off ” Switch. Push pull Switches. Ball Bearing Turntables, with folding legs. Watmel Wireless Co., Ltd. too Imperial Worka, High Street, Cdgware, Middleaex. “ Super Selective ” Coils, Tuners, Wire-wound Potentiometers, H.F. Chokes, Pick-up Carriers, Screening Boxes, Wave Traps, Fixed Condensers. 153 FOR MOVING COIL LOUD-SPEAKERS. 1 BALANCED ARMATURE LOUD-SPEAKERS. GRAMOPHONE PICK-UPS. TELEPHONE EARPIECES. ETC., ETC. DARWINS LIMITED i FITZWILLIAM WORKS 1 LONDON: Darwins Limited. U.S.A. Eros House, SHEFFIELD. Darwin & Milner, Inc., 29/3\. Regent St., 1258 1264, West Fourth St. S.W.I. Cleveland, OHIO. GERMANY: FRANCE: BELGIUM: Ritterstrasse 101 R. H. Aquarius, Acieries Darwins S.A. Berlin, 246, Bourse de Commerce, 35. Ruede lOrlent, S.42. Paris. Brussels. j 154 V Stand No. Kmpikk I Tali., Cl round Floor. Memoranda. 1 A1 Darwins Limited, Fitzwilliam Works, Sheffield. COBALT STEEL PERMANENT MAGNETS for Moving-Coil Loud Speakers, Balanced Armature Loud Speakers, Gramo phone Pick-ups, Telephone Ear-pieces, and all other Wireless and Electrical Apparatus. Various special designs of Permanent Magnets for Moving-Coil Loud Speakers will be shown, and complete Loud Speakers of various makes, incorporating these magnets, will be demonstrated on the Stand. 1 02 P* Bulgin & Go., Ltd. ~ Abbey Road, Barking, Essex. Showrooms, 9, 10, 11, Cursitor Street, Chancery Lane, E.C.4. RADIO COMPONENT SPECIALISTS. Large Range, com prising Anode Resistances, Battery Clips, Coils, Connectors, Crocodile Clips, Dialites, Fuseholders, Grid Leaks and Clips, H.E. Chokes, Key Switches, L.E. Chokes, Mains Plugs, Milliammeters, Remote Controls, Switches (large variety), “ Spaghettis,” Terminals, Valve Emission Testers, etc., etc. NEW LINES. Bakelite Dielectric Condensers, D.C. Mains Resistances, Wire-wound Volume Controls incorporating Switches, Moving- Coil Instruments, Thermostatic Delayed Action Switches, Valve Holders, “ Quickwyre,” etc., etc. 1 Whittingham Smith & Go. (Portadyne Radio.) Portadyne Works, Gorst Road, North Acton, London, N.W.10. The Portadyne Radio Receivers exhibited are the latest pro duction of a firm who were amongst the pioneers of portable radio. It is claimed that the manufacturers were one of the first to build a radio receiver incorporating a self-contained loud speaker. The improved Atlantic Screen Grid Four Receiver, which lias been an outstanding success for many months past, will continue to meet with a ready demand from those who require a receiver of high quality at a reasonable price. An addition to the Portadyne range is the transportable model encased in a walnut cabinet of pleasing design. This receiver is up to the usual high standard of Portadyne products, and is a notable advance on previous models, particularly in respect to ease and range of control and low maintenance costs. Portadyne Receivers continue to be famous for workmanship and general finish. inn Mr, Radio Dealer you wish to see the most- in the shortest possible time—to make comparisons, and get first-hand informa tion on all that is latest and best for 1931/2 Season COME ALONG TO THE i EMPIRE HALL — . Mi STAND No. 105 Radio - Grams, Receivers Speakers and Components by all the most popular makers are available for your inspection, Also a wide range of Battery Charging Equipment. Our Technical Staff will gladly furnish fullest details on anything Radio. We hope to see you! BrownBrothers -*■ Allied Companies -* THOMSON and BROWN BROTHERS Ltd BROWN BROTHERS (Ireland) L-TD. Head Offices and Warehouses. Wholesale only: GREAT EASTERN STREET, LONDON, E.C.2 126, GEORGE STREET, EDINBURGH. I {ranches : Aberdeen, Belfast, Birmingham, Bristol, Cardiff, Dublin, Dundee, Glasgow, Leeds, London, W.l, Liverpool, Manchester, Newcastle, | and Southampton. Stand No. Empire Hall, Ground Floor. Memoranda. 104 A. J. Dew & Co., Ltd. v 32, 33, 34, Rathbone Place, Oxford Street, W. 1. The main interest appeal of this Stand is to the Radio retailer. The exhibits will comprise a representative selection of products by the leading British manufacturers, and embrace everything which is required by the retailer for stock or service purposes. Special prominence will be given to the new season’s models of Receiving Sets, Radio-Gramophones and Loud Speakers, including models by Pye, McMichael, Marconiphone, Ekco, Brownie, Ferranti, Varley, Ormond, etc. London and provincial representatives of the firm will be in attendance to render traders every possible assistance in selection and choice of apparatus to suit their own particular districts or businesses. ,1 1 QC Brown Brothers, Limited, Great Eastern Street, London, E.C.2, and Branches. •'Y L A representative display of Radio-Gramophones and Consoles of all the finest makes, and the new Radio-Gramophone with Recorder. Accumulator Charging Plant of all prominent makes, New Mercury Arc Charging Equipment and Small Engine-driven Charging Equipment. Receiving Sets (Mains and Battery operated) and Portable Sets. Loud Speakers and Units. A full range of Components, including Westingliouse H.T. Units, Pick-ups, Electric Gramophone Motors, and the new Ekco Radio Recorder. 157 ’•‘x\ it}') ftgr X trade a?38SS£ THE ONLY PERFECTED BROADCAST MODEL IS AT STAN® 107 . : : BECAUSE i The Stenode Radiostat can solve the problem of the 1 increasingly congested ether. © The Stenode Radiostat can give you Stations separated •by only 3 to 4 metres on the Low Wave Lengths. ! The Stenode Radiostat gives a 5 Kc. separation between Stations. © ©lYl/Y The Stenode Radiostat gives you this unparalleled selectivity combined with perfect reproduction. © ©]> l*Y on Stand 107 can you see the Set of To-morrow, to-day. Manufactured by : F. W. SMURTII WAITE, A.M.I.R.E. Wallington 1982. 24, BELMONT ROAD, WALLINGTON, SURREY. Under Licence of The British Radiostat Corporation, Ltd. Main Agents and Distributors : A RUN ELECTRICAL SUPPLIES, LIMITER, Mayfair 0368. 35. DAVIES STREET, W.l. . ins Stand No. Empire Hall, Ground Floor. Memoranda. 1 C\f. Epoch Radio Manufacturing Co., Ltd., -1- v/U Exmouth House, Exmouth Street, Clerkenwell,E.C.l. I Epoch range of Moving-Coil Speakers, comprising a large variety of permanent magnet and energised speakers for the home, manufacturers, public address work and cinemas. Forty models. 1 07 W. Smurthwaite, JLHJ’/y 24t Belmont Rd., Wallington, Surrey. “ The Stenode Radiostat ” Receivers, in table and console types, self-contained all A.C. and battery models, etc. “ Macgregor Station Indicator,” working in conjunction with a Stenode Radiostat, indicates both the name and location of any broad casting station to which the receiver may be tuned. ” Band Pass A.C. Three ” Receiver, an instrument known for high selectivity, long range and good reproduction. Examples of individually built radio-gramophones in cabinet work to match period or other furniture. Public Address Amplifiers for outdoor or indoor use. 1 AQ Magnavox (Great Britain) Ltd. JLI/O 89, Kingsway, London, W C.2. Electrically Energised Moving-Coil Speakers. Permanent Magnet Moving-Coil Speakers. 1 PERMANENT MAGNET MOVING-COIL , '-'i SPEAKERS 1 ' 'r CONE SPEAKERS .. - "r VALVEHOLDERS AND SWITCHES ,• [i. Electrical Radio Co., Ltd., Radio Works, Nottingham Road. Mansfield, Notts. Whiteley 159 Memoranda EMPIRE HALL: FIRST FLOOR. LOUDSPEAKER SUPPLY ARRANGEMENTS. the B.B.C. Stand is located the apparatus used to V Jsupply programmes of music, speech, etc., to all Loud speakers operating in the Exhibition. The programmes thus distributed are obtained either from the B.B.C. head quarters at Savoy Hill or from the small studio on the Stand. The programmes originating from Savoy Hill are identical with those being radiated either by the London Regional or the London National transmitter at Brookman’s Park. Wire less link, however, is not employed, the apparatus on the Stand being connected directly to the amplifier at Savoy Hill through the medium of the G.P.O. telephone lines, special circuits being used for the purpose. In the small studio on the B.B.C. Stand are a microphone and a gramophone with an electrical attachment by means of which a programme of suitable music is distributed when the Broadcast transmissions are not available. With regard to the apparatus on the Stand, to the left of the main amplifier unit will be seen a small rack upon which is mounted the input equipment, comprising five stages of re sistance-capacity coupled low frequency amplification. The output from this rack is fed to the x>ower amx>lifier, which consists of two stages of push-pull resistance-capacity coi^led ami)lification. The high tension and low tension supfilies for the latter are derived from the Motor-generator set which may be seen on the right-hand side of the Stand. This machine delivers about 40 amperes at 17 volts to the filaments of the four large valves emi>loyed in the output stage, whilst approxi mately kilowatts at 3,000 volts is dissipated at the anodes of these valves. The Loudspeakers are fed in parallel, through a number of separate circuits which supply the various parts of the Exhibition. ;■ B.B.C. EXHIBIT. s Distribution is the keynote of the B.B.C. Exhibit at Olympia. The question of distribution is regulated by the Union International de Radiodiffusion, whose headquarters are at Geneva. The President of the Union is Vice-Admiral Carpendale, C.B., Controller of the B.B.C., and the Secretary General is Arthur Burrows, director of Programmes to the British Broad casting. Company in 1924. 100 Memoranda. The International Union is composed of experts from all the European nations whose duty it is to look after the interests of the 90,000,000 listeners they represent. The Union established the Brussels Checking Station, which checks the wavelengths of 200 stations every night. Two charts are on view which clearly indicate the improve ment in stability of transmitters during the last few years. One of the Brussels wavemeters on which the checking is done will be on view ; also a Transmitter Wavemeter which is used at each transmitter to enable the wavelength to be checked, and regulated to the allotted figure. HOW BRITISH LISTENERS GET THEIR PROGRAMMES. Distribution in Great Britain is explained by means of a large map of the British Isles. This map is coloured according i to the density of the population ; a key to the population . represented by the various colours is by the side of the map. On the map are shown all the B.B.C. Transmitting Stations and the telephone line system connecting them for simultaneous broadcasting. These lines will be shown in two colours, one representing the existing system and the other showing the complete system when all the high power twin wave transmitters are erected. The approximate population in the service areas of the high power transmitters is also shown. By studying the map it will be seen that the B.B.C. Stations are placed in the most advantageous positions ; in fact over 98 per cent, of the total population of the British Isles are within the service area of one or more of the B.B.C. Stations. In the centre of England is Daventry 5XX, the only long-wave B.B.C. station. This station is of the greatest value for the following reasons : ! i (1) The attenuation (i.e.. the rate at which the signals weaken as the distance from the transmitter is in creased) is much less than on medium wavelengths. (2) The distance at which it can be received without fading, and night distortion becoming noticeable, is far greater on a long wave than on a medium wave. (3) 5XX supplies the National Programme to districts which are outside the radius of some of the medium national transmitters. The population inside the service area of 5XX is 43,000,000. At the B.B.C. Bookshop on Stand 211 all the B.B.C. publications will be on sale. 161 Woe BROADCASTER AND WIRELESS RETAILER The Leading RADIO TRADE NEWSPAPER PUBLISHED WEEKLY “The Broadcaster”—giving red-hot news and reliable and authoritative views—is as up-to-the-minute as modern machinery and modern methods of newsgathering can make it. It offers the finest and best technical service. Thousands of dealers’ problems are solved by our staff of experts. “The Broadcaster’s” test reports are carried out in its own up-to-date laboratory. “The Broadcaster” Stand-by-Stand report of the Exhibition gives a VISIT complete illustrated account of what ^ A i. | r-v every exhibitor is showing. Get a O I A IN LJ copy at Stand Number 154. N° 154 II you wish to find a manufacturer's Stand quickly, require trade information, or wish to ring up somebody, go to " The Broadcaster" Stand Number 154. If you have a trade friend to meet, or an Exhibi 7/6 tion appointment to keep, make your rendezvous "The Broadcaster" Stand. Per Ann. Any technical queries handed in will immediately be passed . V on to the Technical Department / Post Free and dealt with by post the same day. 1(52 Stand No. IOmimiik I Lux, First Fi.oou. Mijmoranda. 1 Cl S. Kalisky (Aldgate), Ltd., 75, Aldgate High Street, London, E.C.3. Radio Sets and Accessories of all descriptions, including :— Sopranist H.T. and L.T. Batteries. Sopranist Battery Testers. Chokes, etc., etc. Aerial Wires and Equipment Specialities. 1 S2 Wright & Weaire, Ltd. 740, High Road, Tottenham, London, N. 17. Tel. : Tottenham, 3132. ’Grams : Writewea, Tottlane, London. Wright & Weaire can claim the distinction of having been particularly responsible for the recent revival of the Super Het Circuit, which, in its modern form, is proving so extremely popular and efficient. The Wearite Super Het Coils and other Super Het Components, which made the revival of this circuit possible, may be seen on this Stand. Visitors should also inspect the very complete range of Wearite Components, which cover every possible requirement of the Radio Constructor and Manufacturer—Coils for every type of receiver, Coil Screens, Frame Aerials, Switches, Valve Holders, Rheostats, Volume Controls, Potentiometers, Power Transformers and Chokes, Paxolin Panels and Forms, Earth Tubes, etc., etc. 1 The British Ebonite Co., Ltd., Nightingale Road, Hanwell, London, W. Display of Ebonite Sheet Panels, Rods, Tubes, Mouldings. Extruded Sections (Labour Saving). Special display of Ebonite Becol Low Loss Formers, large range of new sizes. See the largest Ebonite Low Loss Former known. “The Broadcaster & Wireless Retailer,” 154 93, Long Acre, London, W.C.2. A Weekly Trade Newspaper, 7s. Gd. per annum (traders only). Three enlarged Exhibition Numbers—with up-to-the-moment information—September 12th, 19th and 26th, which together form a complete guide to the Exhibition. Issue dated Sep tember 26th also contains laboratory reports upon exhibits shown at the Exhibition. u;:i Stand No. Empjrk Hadi., First Floor. Memoranda. 1 CC The British Radiophone, Ltd., Aldwych House, Aldwych, W.C.2. Ganged Condensers, Moving-Coil Speakers, Moving Iron Speakers, Loud Speaker Units and Chassis, Transformers, Turntables for Portable Receivers, Pick-ups; also Pressed Parts, Turned Parts and Manufacturers' Components. 1 Jewel Pen Co., Ltd., (Radio Dept.). 21/22, Great Sutton Street, Clerkenwell, E.C. 1. Jewel Pen Co., Ltd. (Radio Dept.) will be showing their RD 40 Detectors, as specified and used in the “ Wireless for the Blind Fund ” Crystal Sets, RD 39 Switches, together with other “ Red Diamond " Components. They will also exhibit specimens of turned and machined Ebonite parts for all purposes. Baird Television, Ltd., 157 1S3, Long Acre, London, W.C.2. The Baird Home “ Televisor" Receiver, Components, and Amateur Constructor’s Kits of Parts comprising all the apparatus necessary for the reception of the vision trans mission from Brookmans Park. 1 CO E. Paroussi (Parex), 10, Featherstone B’ldgs., High Holborn, W.C.l. Manufacturers of Radio Components, Screen and Coil Specialists, Metal Cabinets for Wireless, Gramophones and Talkies. Other “ Parex " products, S.G. Valve Holders, H.F. Chokes, Fixed Resistances, Differential Condensers, Drum Dials, Television Scanning Discs, etc. Coils and Screens for all published circuits. Auto Electric Devices Ltd. 159 Diamond Works, Brighton, Sussex. Gramophone Pick-ups, Volume Controls (Log law), Double Faders (Log law), Potentiometers, Electric Gramophones, Pick-up Drives. W. & T. Lock, Ltd. 160 St. Peter’s Works, Bath. “ KABILOK " Cabinets of Distinction. A full range of Pedestal and Table Types in Oak, Mahogany, Walnut, etc., including :— The “ Beaufort" Radio-Gram Cabinet. The “ Pulteney" Combined Receiver and Loud Speaker Cabinet. The “ Classic ” and “ Moderne " Transportable Cabinets. Home Constructor Cabinets in a complete range of Loud Sneaker Cabinets, including the " Mellotone, Clanonette, and “ Claribell " Cabinets ; the new “ Kelston ” Receiver Cabinet, etc. 104 Stand No. Empire Hall, First Floor. Memoranda. 1 f. 1 The Donotone (Regd.) Loud Speaker, ^ 40, Furnival Street, Holborn, London, E.C. 4. The Donotone, with its tuned gongs, is entirely different from any other Loud Speaker, latest models on the Stand include the Super and the Ideal. Public Address Equipment will also be on view. This can be used for reproduction of speech and music. 1 /CO Radio Service (London), Ltd. 105, Torriano Avenue, Camden Road, N.W. 5. Radio Receivers and High and Low Tension Accumulators. 1 Redfern’s Rubber Works, Ltd., Dawson Street, Hyde, Cheshire. “ Ebonart ” (Regd.) Radio Panels, Black and Mahogany colours, with non-metallic polish, also Moire surface Black, “ Bulwark ” Radio Panels, Black and Mahogany colours, non- metallic polish, also Wavy surface design Black. Redfern's Ebonite Low-Loss Coil Formers, Coil Quoit Formers, “ Ebonart ” and “ Bulwark ” qualities. Ebonite Choke Formers, Ebonite Sheet, Sections, Rod, Tube, Lead-in Tubes, Battery Boxes, Lids, Stoppers, Ebonite Utensils for handling acids. Accumulator Trays of Acid-resisting Rubber. Pure Rubber Loud .Speaker Mats. Mouldings in Ebonite, Rubber and Bakelite. 1 /Of. Thomas De La Rue, & Co., Ltd., Telenduron Works, Shernhall Street, Walthamstow, E.17. The exhibit will demonstrate the extension of mouldings to actual cabinet work, with effects reproducing polished hard woods, and colour schemes for wireless components and sets. Practical demonstrations in mouldings for the trade, in various suitable materials—Bakelite, Plastic, Cellulose Ace tate, etc., showing the accuracy obtained, and problems solved by our expert designers. 1 /CC The Beaver Electrical Supply Co J-vJO 5, Great Chapel Street, W. 1. Will be showing a full representative range of all Manufacturers' Components, All Mains Receivers, Portable Receivers, Moving-Coil Loud Speakers, Electric Gramophone Motors, etc., together with the new range of “ ELITE ” Components I for which they are the sole distributors. - 1G5 - Stand No. Empire Ham., First F loo it. Memoranda. 1 Hillman Brothers, (Formerly Ellison & Hillman). 123 & 125, Albion Street, Leeds. Messrs. Hillman Brothers the Wholesalers from the North of England showing at Olympia are, as in previous years, arranging their Stand for the benefit of Traders from this area. As part of the “ Sound Service ” which they provide for Dealers, they are arranging a collection of new models on the Stand which are judged to be the most useful selling lines for the coming season. The 1931-32 range of Marconiphone products will be prom inently displayed. Messrs. Hillman Brothers are one of the appointed Marconi Distributors. In addition, of course, a comprehensive range of Receivers by Ekco, McMichael, G.E.C., Dibben, Red Star and Ultra will be shown, among many others, in table and console models together with a selection of Radio-Gramophones. To complete their range for the Dealer, a varied collection of Loud Speakers, Components, Batteries and other Accessories will be on view. I f/7 Itonia Gramophones, Ltd. ^" 58, City Road, London, E.C.l. This Display will comprise the Itonia range of All-Electric Radio-Gramophones—Model 503, a 3-valve instrument employing 2 screened-grid and power valves; output fed to a moving-coil speaker. Model 505 is a 2 valve all-electric radio gramophone employing detector and pentode valves, mains aerial, and built-in speaker. Features of this exhibit are also all leading sets, components and B.R.V.M.A. Valves which Itonia factor. Kid ■ Stand No. Empire Hall, First Floor. Memoranda. 1 /CO S. A. Lamplugh, Ltd. Little Park Street, Coventry. SILVER GHOST INDUCTOR DYNAMIC SPEAKER CHASSIS. i SILVER GHOST INDUCTOR DE LUXE CABINET MODEL. SILVER GHOST INDUCTOR STANDARD CABINET MODEL. SILVER GHOST INDUCTOR MINOR CABINET MODEL. SILVER GHOST “ INDUCTASET,” A new all-electric Set, embodying the Inductor Dynamic Speaker. SILVER GHOST SPEAKER COUPLING UNIT. A new Choke output Filter device. 1 /CQ Adie & Co., Ltd ^ ^ 2, Aldermanbury Avenue, London, E.C.2, Manufacturers of Adico Dry Batteries for Wireless, Telephones, Pocket Lamps and all other purposes. Specialities : Adico New Improved High Tension Batteries in all voltages; Adico Green Label High Tension batteries in all voltages. Henderson Wireless and 170 Electrical Service, 54. Queen's Road, Brighton. Distributing Agents for all the Principal Radio Manufacturers. A special show of Marconiphone Products, Mains Radio Sets, Consoles and Radiograms. 1 71 Arding & Hobbs Ltd., Cl&pham Junction, S.W, 11. Telephone : Battersea 5555. Manufacturers of the “ Munt ” Concert Power Amplifiers and public address equipment. Also service agents for the leading manufacturers. 107 CONDENSER FOR *»*' „.cand ...uiion and-*(1 Drum Ganged Con : CYLDONGangtrol, single and ganged Extensers with insulated Commutators /or use with Varley Square Peak Coil CYLDON MIDGET GANGS SPECIFY CYLOOA /or Varley Square Peak Coil CYLDON Intermediate Fre quencyTuning Condensers CYLDON is the only Extenser for Extenser Sets— CYLDON Duplex Illuminated SlowMotionDial/orCYLDON perfect wavechange switch, noiseless wipe contacts, Extenser? 4-pillar construction, rigid and foolproof. Be wise— (tensersCYLDON Log mid-line Con- refuse to accept substitutes for specified CYLDON EXTENSERS in Kits of Parts you buy. Don’t CYLDON Junitog Condensers CYLDON Air Spaced Di/fcrcn- risk trouble—those who know build with CYLDON. rial Condensers There’s a type for every purpose. CYLDON Series Gap and Short Wave Condensers cGn. densersCYLDON Transmitting FOR EX TENSER SETS Ask for New Catalo STAIUI) v' Stand \o. K.mimkk Haix, Fikst Fi.ook. MbiOkanda. 1 72 Sydney Si Bird & Sons, Limited, " Cyldon Works, Sarnesfield Road, Enfield Town. Variable Air spaced Condensers, of all types, including Log mid line, .Square Law, Straight Line Frequency, Straight Line Capacity. Gang condensers in all above laws. Slow- motion illuminated drum dials. Behind panel dials. Slow- motion condensers. Special type Condensers. Intermediate frequency tuning condensers for super-hets. Detachable trimming condensers, etc. ! I 1 77 Overseas Trading Corporation, A. / vJ 18, Ganton Street, Regent Street London, W.l. Manufacturers and Factors of all British Sets and Components. Sole Distributors to the Wireless Trade of “ MIVOICK ” Home Recorder. Specialists in Portable—Transportable 4-valve S.G. Sets, 5-valve suitcase portables, “ Super- Century ” Super Heterodyne sets, embodying only the best all British Components. The Wireless Retailers’ Association of 174 Great Britain and Northern Ireland, 1, Mitre Court, Fleet Street, E.C.4. Literature describing the Association’s aims, objects and activities, etc. Representatives will answer all enquiries. 1 7C Hobday Brothers, Ltd. 21-27, Great Eastern Street, London, E.C. 2. This exhibit is of particular interest to the Wireless Trader, in that it comprises a comprehensive display of all the latest Radio Receivers, and Radio-Grams of the leading makers. In addition, a great variety of Radio Components are also shown, which include Accumulators, Battery Eliminators, Cabinets, Coils, Condensers, Loud Speakers, Switches, Transformers, and everything required by the Trader. 1 If. East London Rubber Co., ^ 29-33, Great Eastern Street, E.C. 2. Full range of all leading makes of Receiving Sets by all best known British makers. Portable Mains and Battery Component Parts of all best description. Kit sets. Charging Plants. Latest type Loud Speakers, Eliminators, Cabinets, etc. ltii) Sjgjjj \'r;/ ; «!§! F. W. SMURTHWAITE S mm AiMiLRiE* i VISIT US ON Belmont Road, W STAND 152 Wallington, Surrey. empire hall. .. •Phone : WALLINGTON 1982. ■o ■o mas MANUFACTURER OF ■l® INDIVIDUAL RADIO APPARATUS. w o o 4 wS EARIT Genuine period design cabinets to match existing furniture, etc. PO m Complete installations for town and country houses, yachts, public institutions, mm hospitals, etc. WRIGHT&WEAIRE Ltd. ■o w Contractor to the L.C.C.. B.B.C. 740, HIGH ROAD, 1 MIDDLESEX C.C.. etc. TOTTENHAM, N.I7. 'Phone:Tottenham3 847/8/9. A m ■ps STAND No. 107 M Mil YAGERPHONE ALL BRITISH RADIO. Your visit to STAND 222, where a complete range of Yagerphone Radio Grams, and Receivers will be ex hibited, will convince you of their wonderful value and their------irresistible . appeal for quality and pleasing appearance. Jsk to see Model Y.30I, 3 V., S.G. Radio-Gram., Oak (,/f.C.) 35 Guineas 1 Jllso Portables, Transportables, jg Model Y.303 and Loud Speakers. 3-VALVE S.G. RECEIVER. Battery operated. Circuit: Employs one stage of •PHONE: ENFIELD 1321. screened H.F. amplification, detector and power out. put with Voltron. Panasonic Transformer. A set capable of receiving a large variety of Continental stations. Built on analUmetal chassis and fitted in YAGERPHONE LTD., a cabinet of unique design. 1 a CHARLOTTE CABINET WORKS, Loudspeaker: Latest balanced armature ™ type, retail price...... Gna. PONDERS END, MIDDLESEX. 170 Stand No. Empire Hall, First Floor. Memoranda. 1 77 Partridge & Mee, Limited, ^ * 26, Dover Street, Leicester, 74, New Oxford Street, London. All kinds of Transformers and Chokes both Mains and for Speech and Special Purposes. Loud Speakers of all types. All types of Amplifiers from small wireless requirements to Public Address Equipment. Wireless Sets and Resistances. Small electrical apparatus, etc. 1 78 The Garrard Engineering & A/O Manufacturing Co., Ltd., Newcastle Street, Swindon, Wilts. “ GARRARD ” Regd. Electric and Spring Motors for Radio- Gramophones and Electrical Gramophones, comprising the following models :— Universal Electric Motor, No. 101. Induction Electric Motor, No. 201. Induction Electric Motor, No. 202. Super Double Spring Motor. No. 10B. Double Spring Motor. No. 11B. Double Spring Motor. Junior B. Double Spring Motor. No. 30. Double Spring Motor. -= No. 12BB. Single Spring Motor. 3 No. 20. Single Spring Motor. Also " GARRARD ” Main Springs and Lubricants. — 171 EVERYTHING © FOR THE RADIO FAN The Troublefree Way— SEE ALL THE SETS WORTH BUILDING —to Better Radio. rn PILOT KITS of Parts, packed in sealed cartons for all Sets described in “ Popular Wireless,” “ Amateur Wireless,” “ Modern Wireless,” “ Wireless Magazine ” and ” Wire less Constructor ”—prepared under the expert supervision of Mr. Scott - Worthington, Managing Director. Coil Quoits, Frame PETO-SCOTT CO. LTD. Aerials, Cabinets, Speakers, Head Office: 77, CITY ROAD, LONDON, E.C.1 Clcrkcnwcll 9406. Eliminators, Short-Wave Equip 62 HIGH HOLBORN, LONDON, W.C.1 ment—in fact, everything in British 33 WHITELOW HOAD, CIIORLTON-CUM-HARDY, Radio concentrated under one roof. MANCHESTER. Our 3-Way Plan gives you a new 7 ALBANY ROAD. NEWCASTLE, STAFFS. opportunity of possessing better Radio. See us at the Show— KITS of PARTS otherwise, send for full particulars. C.O.D. CASH or HP. 172 Stand No. Empire Hall, First Floor. Memoranda. 1 7Q Pet0 Scott Co., Ltd., A S 77, City Road, London, E.C.l. Pilot Kits of Parts for sets described in the leading technical periodicals. Frame Aerials for Super Heterodyne Receivers. Coil Formers (Coil Quoits). Red Triangle Ebonite, Aluminium and Wood Panels. Metal Screens for Coils and Valves. Variable Condensers. Complete Range of Radio Accessories. 1 SO The Johnson Talking Machine Co. Ltd., Academy House, 96, Clerkenwell Road, E.C.l. Branches : 52-56, Wood Street, Liverpool. 31-33, Holloway Head, Birmingham. 136, Renfield Street, Glasgow. Manufacturers of Radio Receivers and Radio-Gramophones, Mains and Battery operated. Permanent Magnet and Mains-excited Moving Coil Speakers. Factors for all well-known makes of Radio and Radio Acces sories and Radio-Gramophone Accessories. B. & S. Electrical Co. Ltd •J 181 9, Brunswick Place, City Road, N.l. Telephone: Clerkenwell, 0711 and 0712 Superheterodyne Receivers. 7-valve All Mains Chassis. 7-valve Midget Console and Radiograms. 5-valve Superhet Portables, Table Model. 5-valve Superhet Portables, .Suitcase Model. 2 and 3-valve All Mains Receivers. 2-valve All Mains Radiograms. 4- valve S.G. Portables. 5- valve Receivers. Suitcase Portable Turntables and Pick-ups. Loud Speakers and assorted Components. 1 QO The British Hard Rubber Co., Ltd., Wharf Road Works, Ponders End, Middlesex. The main feature will be the introduction of a new development in Ebonite manufacture. PERMCOL Non-discolouring Ebonite Sheet. PERMCOL Non-discolouring Ebonite Panels. PERMCOL Non-discolouring Ebonite Lengths. This material, which has a mirror-like polish, is the result of several years’ research work, and is not liable to discoloura tion. It is entirely a British product. Also, Ribber Former, Rod and Tube in Matt Ebonite ; machined sections, blocks and bases for all components and accessories. 173 Stand No. Empire Hall, First Flour. Memoranda. I 1 O'! Calders, Ltd M Fancy Box Factory, Ryland Road, Kentish Town, N.W.5. Exhibited on this Stand are various designs of Radio-Gramo phone Cabinets, Portables and Transportable Cases, all classes of Cabinets suitable for the Radio Trade. Exponential Horns and Electro-Dynamic Moving-Coil Repro ducers for sound reproduction of the famous “ TRUVOX” manufacture. Extensively used in Public Address work, and fitted in approximately 2,000 cinemas. From GO in. to 15 ft. air columns. Special Stormproof Trumpets for outdoor Public Address work which will withstand all inclement weather conditions. Specially featured are the Super Electro- Dynamic Unit and a new type Balanced Armature Unit. CALDERS CASEWORK. Behind every Cabinet and Case leaving our works is a guarantee : of quality, made possible by the use of well-seasoned timber, first-class materials, plus highly skilled workpeople. Our production is large, hence our prices are low, but while our manufacture of some types of Cabinets runs into thousands, we are always ready to execute singles, as an entirely separate department is retained for this purpose, thereby offering to the small purchaser a boon which has been greatly appre ciated. 1 ftd- Cadisch & Sons, ^^ * 5 & 6, Red Lion Square, London, W.C.l. The exhibits have been carefully selected to represent the advance made in the Radio Industry during the past year. Prominence has been given to All-Electric Receivers and Radio- Gramophones incorporating the popular Super Heterodyne and Band Pass Circuits. There is a special display of Console models. ! On the Stand will be found mains and battery-operated Receivers by the following makers: Ekco, Pye, G.E.C., Cossor, Amplion, Ediswan, McMichael, S. G. Brown and Edison Bell. Also Radio-Gramophones incorporating the latest circuits and with most attractive cabinet work by Messrs. McMichael, Edison Bell, Faraday and Ekco. Moving-Coil Loud Speakers for A.C. and D.C. operation and Permanent Magnet types, this season's models by the follow ing Companies : B. T. H., Amplion, Celestion, S. G. Brown, and the newly formed Magnavox Company of Great Britain. Inductor Speakers by G.E.C., Lamplugh and Ferranti. Eliminators : By arrangement with Messrs. E. K. Cole, Ltd., ! and the Regentone Company a complete range of all new types ! will be on exhibition. Accessories : A comprehensive range of improved Wave Traps, Pick-ups, Coils, Condensers, Frame Aerials, etc. A special staff of salesmen and technical experts will be on duty each day during the Exhibition. i 17-1 ft Stand No. Kmpirk 11am., First Fi.oor. Mkmoranda. Electrical Devices Co., 185 12, Gt. James Street, W.C.l. KLDECO SCREENED GRID FOUR PORTABLE, SINGLE i DIAL CONTROL.—This model has been further perfected. The finest quality British components are used throughout. | The cases, being covered with best British hide, have a par ticularly refined appearance. This Receiver is very selective, and designed to give exceptional reproduction of British and Foreign broadcasting. ELDECO SCREENED GRID FOUR PORTABLE.—This popular model employs the same circuit as the above. ELDECO SIX-VALVE SUPER-HETERODYNE PORT ABLE.—This remarkable Receiver is the outcome of con siderable research. There is no European station of any consequence that it cannot reproduce. A feature of great convenience is the revolving lid, which obviates the necessity of turning the case round. : 1 Manufacturers Accessories Co. (1928) *-OU 85, Gt. Eastern Street, London, E.C.2. Ltd., Receivers, Radiograms, Loud Speakers, Speaker Units, “ Maco ” i Accumulators, H.T. Batteries, H.T. Units, Transformers, Battery Cords, Battery Testers, Battery Chargers, Aerial Wires, Insulators, Pulleys, Switches, Earth Tubes, “ Maco ” Cabinets, Panels, Panel Brackets, Coils, Coil Holders, Con ! densers, Pick-ups, Terminals, Valves, Valve Holders, Volt meters, Ammeters and everything for the Wireless Trader. 1 Q7 P. R. Products, Ltd. " p. R. House, 14, Newgate Street, London, E.C.l. P.R. Masts, Aerial Wire and Accessories. P.R. Valves in all ranges. Portables, Transportables, and Cabinet Sets and Kits. i Speakers, Units, Cones, Transformers, Tuning Units and Coils. 1 Pioneer Manufacturing Co. Cromwell House, Fulwood Place, London, W.C.l. Efficiency Components, including “ Pioneer ” Safety Contact Switches (as used by H.M. War Office). Also exhibiting Technical Test Reports from the Radio Press, etc., on “ Pioneer " Switches. i ! R. F. Graham & Co., I 189 “ Norbex & Citex " Works, Cambridge Road, Kingston-on-Thames. “ Norbex ” Nickel-plated Brass Sockets for valve holders (panel 1 mounting), Plugs to fit sockets, and the “ Norbex ” Universal Crystal Detector, Soldering Tags, etc., “ Citex ” Hand Fire Extinguishers as installed throughout this Exhibition to stands. 17 fl Stand No. I-'.mj'iuk Hall, First Floor. Memoranda. 1 QO Sel-Ezi Wireless Supply Co. , Ltd., ^^ 1, Soho Square, London, W.l. This Stand will be devoted in the main to a comprehensive display of the new products introduced this season by Lotus Radio, for which we are the sole concessionaires for London and the Southern Counties. The Lotus programme this year is one which will appeal to every trader, and the new 3-valve All-Electric Table Model, incorporating a Moving-Coil Loud Speaker, should not be missed, In addi- tion to this, there will be on show a complete range of Lotus Components, many of which have been drastically reduced in price. The remainder of the display will be of a general nature, showing the latest products by the various British Manufacturers. 1Q1 Atalanta, 1-3, Brixton Road, London, S.W. 9. The “ Atalanta ” Screwdriver in various models for construc tion, assembly and repair work, etc. The “ Atalanta ” Chuck for holding small taps, reamers, broaches, etc. The “ Atalanta ” Drilling Jig for drilling holes diametrically through round bar, etc., with ease and accuracy. 1 Q2 Baudels, Ltd. 36 to 40, Newgate Street, London, E.C. Makers of the “ Coronet ” series of Wireless Receivers, which includes :— Coronet 2. Coronet 3. Coronet Suitcase 5. Coronet Suitcase Screened Grid 4. Coronet All Mains Sets. Wholesalers and B.R.V.M.A. Official 1'actors. 1 07 The Primus Manufacturing Co., Primus House, Willow Street, E.C.2. Electric Dry Cells and High Tension Batteries specially made for Wireless use. All types of Batteries specially made for Screened Grid Valve Sets and all types of Portable Sets. Primus Autocel Type Batteries specially suitable for export markets. A new patented type of Dry Battery with re-charge able cells. Loud Speaker Chassis with Triple Cone and Permanent Magnet Moving-Coil Loud Speaker assembly. 171* Stand No. Empire Hall, First Floor. Memoranda. 1 04 The Park Royal Engineering Co., Ltd., -L /I Cumberland Avenue, Park Royal, N.W.IO. Exhibit consists of Electrical Measuring Instruments, various sizes and ranges, suitable for radio use. These include Volt- Ammeters for test purposes (bench type), Small Panel Mounting Milliammeters, Voltmeters, also Pocket Circuit Testers. T QC A. W. Gamage Ltd., Holborn, London, E.C.l. The exhibits on this Stand consist of the newest ideas in Radio Receiving Sets (both Battery and Electric Models), and Components. These will be of interest because of their fine appearance, per fection of tone, selectivity, and volume, their economical merits and assurance of long service. Of particular interest are our famous Two and Three Valve Sets, which are up to the minute in design, and incorporate all the latest im provements. Other features on the Stand are Portables, Trausportables, and Morse Apparatus. A stall of experts is at hand to give advice and help in choosing. Gutta Percha Co., Branch of Telegraph Construction & Maintenance 196 Co., Ltd., Wharf Road, City Road, London, N.l. Exhibit will consist of Magnetic Alloys in various forms for Cores for L.E. Intervalve Transformers, Cores for E.F. Chokes, Cores for Transformers dealing with very small inputs, such as Microphone Transformers, Armatures for Radio-Gramophone Pick-ups and Magnetic Alloys for screening in radio receiving sets. R. G. Greatrex & Co., 197 184, Regent Street, London, W.l. R. G. Greatrex 2-valve Electric Portables, R. G. Greatrex 3-valve Screened Grid Electric Portables, Newton’s Charging Plants from 6 amp. 30 volts up to 10 amp. 65 volts. Newton’s Constant Potential Battery Charger, 2, 4, 6, and 12 volt, 70 amp., McMichael Receivers, Atlas Eliminators. 177 G Stand No. Empire Hall, First Floor. Memoranda. 1 QQ William Whiteley, Ltd • j ^ Universal Providers, Westbourne Grove & Queen's Road. London, W.2. Many of Wliiteley’s Customers are unable to visit Queen’s Road during normal business hours. We have, therefore, taken a stand at the National Radio Exhibition to afford such Customers the opportunity of inspecting a representative display from our Radio Department. Marconiphone products will be the main feature on our stand, and, in addition, the latest types of Mains Receivers and Radio-Gramophones, by some of the most famous British Manufacturers, will be shown. Similar stocks will be demonstrated in our Radio Department at Queen’s Road during Broadcasting hours between 9 a.m. and 7 p.m. In addition, any type of Receiver or Radio-Gramophone will be demonstrated in Customers’ own homes, free of cost or obligation. Whiteley’s famous Hire Purchase terms are applied to all Receivers and Radio-Gramophones, together with our comprehensive twelve months’ guarantee of After- Sale Service. Whiteleys is easily accessible from Olympia by omnibus routes : 28, 27, and 127 to Westbourne Grove, also by Metro politan Railway from Addison Road to Queen’s Road, Bayswater. 1 QQ Radio for the Million, ' 63, Lincoln's Inn Fields, London, W.C.2. Copies of “ Radio for the Million ” will be on sale containing full working instructions for the new “ Radio for the Million ” Kit Set V.3. This year nine leading manufacturers— Belling-Lee, Climax, Colvern, Jackson Bros., Junit, Mullard, Pye, T.C.C., and Varley—have combined to produce it at a remarkably low price. It is a screened grid receiver of advanced design for which great selectivity is claimed. The all-metal chassis assembly is particularly simple—only 23 connections; no drilling, no soldering. A feature is the varied choice of cabinets in which it may be housed. Com plete chassis and cabinets will be shown. 200 Churchmans Ltd., Maidenburgh Street, & George Street, Colchester, Ipswich & Peterborough. The above firm, as Eastern County Factors, with depots at Ipswich and Peterborough, are showing a very compre hensive range of Radiograms, Receivers, Speakers, Mains Units and Batteries of the leading manufacturers. 178 Stand No. Empire Hall, First Floor. Memoranda. OA1 Fullotone Gramophones (1929) Ltd., * v/-L 73, Camden Road, London, N.W.l. An interesting range of Radio-Gramophones (Battery and Electric). New 2 and 3-valve Receivers complete with Loud Speaker. A complete range of H.T. and L.T. Eliminators. Cone and Moving-Coil Speakers. 0()0 Lectro Linx, Ltd., 254, Vauxhall Bridge Road, S.W.l. CLIX Resilient and Solid Plugs and Pins, including “ All-in ” Power and Parallel Plugs, Valve and Coil Pins, Resilient and Rigid Sockets, Vicegrip and Springscrew Wander Plugs, Baseboard and Panel Mounting Valve Holders, Panel Terminals (screw), Spade Hook, Ring and Pin Terminals, Anode, Accumulator and ordinary Connectors, Accumulator Knobs and Brackets, Constructor’s Kits. OA7 The Sun Electrical Co., Ltd., 118/120, Charing Cross Road, W.C.2. As Wholesale Distributors our exhibit is intended primarily for the attention of the Trade, and is confined chiefly to a selection of the latest models of receiving apparatus of all types produced by the leading manufacturers. We are showing only new season's models and have purposely restricted the number of accessories and components in our exhibit in order that complete receivers may be inspected to the best advantage. Similarly the range of loud speakers on view consists of recent introductions, but a considerable section of the stand is devoted to a display of radio gramo phones by manufacturers of repute. We would remind our trade friends that the Company places Service first amongst its endeavours—Service before and after sales—Technical assistants are at all times available at the Stand to advise, assist or suggest if desired. It is hoped that visitors will not hesitate to avail themselves of their services. 179 SOME OSBORN RECENT OSBORN SUCCESSES RADIO CABINETS Model No. 218. — READY - TO - ASSEMBLE Specified for the Wireless Magazine A.C. Super “60.” from JO'' Model No. 215.— Specified for the ASSEMBLED READY TO POLISH Popular Wireless Comet “2” and Comet “3.” from 42^6 Model No. 176.— A Speaker Cabinet ASSEMBLED AND POLISHED specified for the Amateur Wireless from Room - to- Room “ 2. » 1 Model No. 219.- MACHINED READY TO Specified lor the SPEAKER ASSEMBLE from 6/". Wireless World Super ASSEMBLED READY TO Selective “5.” CABINETS PO LISH from 9/-. ASSEMBLED AND POLISHED from 12'-. Your friends see more of the cabinet than of the set. A cheap set STAND appears an expensive article when fitted in an Osborn Cabinet. All wood is guaranteed well-seasoned timber thus assuring your set freedom from dampness. Sound, British workmanship through out. No rubbish. All models are carriage paid home. Base board is supplied FREE with all models. Prices are inclusive 205 of metallic fabric for fret fronts. FIRST FLOOR, Call at our Stand for Catalogue, or send 3d. in stamps to:— EMPIRE HALL. DEPT. CHAS. A. OSBORN, R.E.O. The Regent Works. Arlington St., London, N.l Tel. : Clerkenwell e^or. And at 21, ESSEX ROAD, ISLINGTON, N.l (1 min. from the Agricultural Hall). Tel.: Clcrkenwell 5634. 180 I Stand No. Empire Hall, First Floor. Memoranda. 204 Fenders (Wholesale), Ltd., " East Stockwell Street, Colchester. Branches at:—Ipswich, Norwich, Cambridge. This stand is of primary importance to trade buyers and on it will be found a representative range of Mains apparatus both A.C. and D.C., Battery operated Receivers, and Portable Receivers, together with exhibits of Loud Speakers and components which are of special interest to trade buyers. 20 S Chas. A. Osborn, Regent Works, Arlington Street, London, N.l. Phone : Clerkenwell 5095. and at:—21, Essex Road, Islington, N.l. Phone : Clerkenwell 5634. Readv-to-assemble, Assembled-Ready-to-Polish and Assembled- and-Polished Radio Cabinets, Solid British Workmanship. A Cabinet for every set on the market. Speaker Cabinets for all the latest type Loud Speakers. Some recent successes :— Model No. 218. Specified for the “ Wireless Magazine *' A.C. Super " 60.” Model No. 176. A speaker cabinet specified for the “ Amateur Wireless ” Rooin-to-room ”2.” Model No. 215 specified for the " Popular Wireless ” Comet “ 2 ” and Comet " 3.” Model No. 219. Specified for the “ Wireless World ” Super Selective “ 5.” All above models are among those displayed on the stand. 20A Birkbys, Ltd., Woodfield Mills, Liversedge, Yorks. London Manager: R. R. TODD, 188, Willesden Lane, Brondesbury, N.W.6. Phone : Willesden 0325. Manufacturers of “ ELO ” SYNTHETIC RESIN MOULDINGS in Black and all colours for the Electrical, Wireless and all Trades. Also manufacturers of Synthetic Resin, Moulding Powder and Varnish. 1S1 SEE £ See the National Band new Range first—the STAND amazing National Band Radio-Gramophones, 210 Moving-Coil and Cone Loud Speakers and a com Empire Hall plete display of all the leading Radio lines we —an factor. Remember the number, Exhibition Stand 210, a Radio in itself. Exhibition in itself. THSNPSOR.5 DIAMOND 8 BUTCHER 34, FARRINGDON ROAD, LONDON, E.C.1 8JPA Telephone: Clerkenwell 5492 (6 lines). 182 I Stand No. Empire Hall, First Floor. Memoranda. The Automatic Coil Winder & 207 Electrical Equipment Co., Ltd. Winder House, Douglas Street, Westminster, S.W.l. The “ MACADIE ” Automatic Coil Winding Machines, with and without attachment for insertion of paper between layers. The “ MACADIE ” (1931 Model) with new type driving head, which permits of any number of machines being driven off a transmission shaft. The “ DOUGLAS ” Power and Hand Winding Machines, with and without paper insertion attachment. The “ AVOMETER ” (1931 Model), an exclusive combination electrical instrument for measuring amps, volts, and ohms, giving direct and accurate readings without the aid of outside shunts or multipliers. Of)© Slektun Products, V/O 21, Douglas Street, Vauxhall Bridge Road, S.W.l. " SLEKTUN ” PORTABLE.—An entirely new three-valve Portable Receiver, absolutely self-contained, with single dial tuning. The Set is all British, and incorporates a Graham- Amplion Loud Speaker, British valves, Silvertown H.T. Battery, Exide Accumulator. The Set is particularly economical in use, consuming from four to five milliamps. " SLEKTUN ” TRANSFORMER.—Introduced to meet the demand for a transformer of first-class performance at low cost. It is manufactured by a new process to give the mapd- mum constant amplification on all audio frequencies. Ratios . 2—1, 3—1, 4—1. Colassion Ltd., 209 Mark Lane Street Buildings, E.C.3. A newcomer to Radio—the Colassion Electrical Sound Repro ducer has many features which will be of particular interest to all concerned with true sound reproduction. Although numerous types are available main interest will centre on the Colassion Hyper Chassis, which is a Reed instrument so constructed that the armature is under constant tension, thereby allowing of a minimum air gap between the reed and the pole piece with the resultant high amplification without distortion. The movement is explained by a giant novel exhibit “ The Golden Unit,” which should be seen on this Stand. 210 Thompson, Diamond & Butcher, 34, Farringdon Road, London, E.C.l. Radio-Gramophones, Radio Receivers, Speakers, Mains apparatus, B.R.V.M.A. Valves, Accessories, Batteries, Accumulators and Components of all the leading makers including General Electric, McMichael, Ultra, Brownie, Amplion, Ekco, Pye, Osram, Cossor, Mullard, Mazda, etc., etc., the outstanding feature being the range of National Band Radiogramophones, Moving Coil Speakers and Cone Speakers. 183 SHORT 9 WAVES STAND STAND 246 THE 246 / T. & R. ^ An inexpen A short wave sive trans BULLETIN receiver to mitter that / listen to the will cover IS PRINTED world: a thousands of \ F°R / wave me ter. miles. \you/ THE RADIO SOCIETY OF Y GREAT BRITAIN INC. 53, Victoria Street, London, S.W.l. Phone: Victoria 4412. AT STAND NO. 163 YOU MAY SEE IN ) REDFERN’S „ REG. NO.-469456. BLACK AND MAHOGANY n Colours also MOIRE SURFACE NON-METALL/C SURFACE EBONITE DESIGN. IN I mi r |||||■ K ■ ■ \|H H• :> M':: ;'l BLACK and MAHOGANY Colours also Uil\\.irk WAVY SURFACE DESIGN. rnu EBONITE RADIO PANELS EBONITE COIL SHEET, ROD, TUBE, COIL FORMERS. EXTRUDED QUOIT CHOKE FORMERS. SECTIONS. FORMERS. EBONITE, RUBBER and BAKELITE MOULDINGS. REDFERN’S RUBBER WORKS, LTD., HYDE, CHESHIRE—London—Leeds. 184 1 ■ Stand No. Empire Hatx, First Floor. Memoranda. The British Broadcasting Corporation, 211 Savoy Hill, London, W.C.2. On this Stand a comprehensive display of the Corporations’ Publications is available to visitors. These include the three weeklies, “ Radio Times,” ” World Radio,” and ” The Listener,” and also publications in connection with School broadcasts, Talks, and many miscellaneous booklets such as Broadcast English, Studio Services, Household Talks, Iden tification Panel Booklet, etc. All listeners should visit the Stand, where information on all topics of broadcasting may be obtained. 212 Henry E. Taylor, Ltd., “ " 51-53, Church Street, Greenwich, London, S.E. 10. Burndept ” MERRYMAKER ” Receivers comprising two and three valve Battery operated instruments with Cone Loud Speaker incorporated in cabinet which also houses batteries and accumulator. Two-valve A.C. Mains Model universal voltage 100/110 and 200/250 volts 40/G0 cycles. Self-contained Cone Speaker. Two-valve Super A.C. Mains Model with self-contained moving coil speaker. Burndept “ MERRYVOX ” Cone Loud Speaker in walnut cabinet. Burndept Ethovernier Dials, H.F. Chokes, A.C. Switches, etc. 21 T Telsen Electric Company, Limited, Aston, Birmingham. TELSEN HOME CONSTRUCTORS’ SETS. 21 A Home Electric Ltd., 24, Sackville Street, London, W.l. 2-valve and 3-valve All Mains Receivers. 2-valve and 3-valve Radio Gramophones. 7-valve All Mains Super Heterodyne Receivers. Midget Console and Radio-Gram. Models. Suitcase and Table Model Battery Portables. 21 C Rees Mace Manufacturing Co., Ltd. 39a, Wclbcck Street, London, W.l. Portable, Suitcase, S.G. Receivers. All Mains Receivers. Loud Speakers—Moving Coil. Superheterodyne Receivers. 21 A Baker’s Selhurst Radio, * 42, Cherry Orchard Road, East Croydon. Moving Coil Loud Speakers. Cinema equipment. Permanent and Electro Magnets. 21 7 Shapland & Petter, Ltd. ■ Barnstaple, and 18, Newman Street, London, W.l. A Range of “ ART AVI AN ” Loud Speakers in Oak, Walnut, : Mahogany and a Variety of Coloured Cellulose Finishes. 185 ELECTRIC MACO TURNTABLE MACOM MODEL “A” Conversion Type for converting spring driven UNIVERSAL gramophones to electric. Assembled in a few seconds by removing the old turn LOW SPEED table and placing over existing spindle. Complete with voltage adjustment, COMPACT speed indicator, on-off switch, mains lead, ad justable rubber feet >.nd LIGHT-IN-WEIGHT plush covered turntable. £2 -12-6 RELIABLE NO OILING MACOM FREE FROM MODEL “B” INTERFERENCE Manufacturer’s Type Heady for assembly with automatic stop, voltage adjustment, speed indi cator, on-off switch, mains lead, plush covered turn table and rubber feel. £2-15-0 The tested product of 20 years' ex perience and 10 years' patient research. One Unit for A.C. or D.C. Mains of all voltages—littlo deeper than an MACOM ordinary turntable — fitted to any gramophone or radio in a few seconds— low speed unit without gears—cannot MODEL "C” overheat or burn out—no oiling—con \ Complete on metal unit stant speed under any voltage or load plate with rubber feet, variation — free from interference. automatic start-and-slop, Complete ready for use. * correct tracking Pick-up arm, Volume Control,Pick up terminals, voltage ad SEE THIS justment, speed indicator. 31 Gn>. BRITISH MADE ELECTRIC TURNTABLE ON MACOM STAND MODEL “ D ” As Model “C” fitted with Macom Pick-up. £4-12 6 N° 2I8 (FIRST FLOOR, EMPIRE HALL) Enquiries to : JOSEPH LECKER, Sales Manager BETTA ELECTRIC MOTORS LTD. BALFOUR HOUSE I 119-125, FINSBURY PAVEMENT, LONDON, E.C.2 S.F.B. Telephone: National 8838. Telegrams: Echergram, London 186 Stand No. Empire Hale, First Floor. Memoranda. OIQ Betta Electric Motors, Limited. * •*- ^ Balfour House, 119-215, Finsbury Pavement,E.C.2. Display of the Macom Electric Turntable, being a low-speed unit for driving electrically turntables of gramophones and radio-gramophones. Four models are featured for every possible requirement. 01 Q Ericsson Telephones, Limited. ■*" ' 67/73, Kingsway, London, W.C.2. Works : Beeston, Nottingham. “ THE FAN ” MOVING-COIL LOUD SPEAKER is capable of great volume, but its outstanding merits are the fine quality of reproduction and tone. The movement is housed in an artistic cabinet which displays a design featuring its name. 220 “ FaY” Home Recorders, Ltd., 121, Victoria Street, Westminster, S.W.l. Telephones : Victoria 7784 & 5. Telegrams : “ Fayedisk, Sowest, London.” On Stand 220 will be found a display of the full range of Fay Home Recorders. There are three models—the Acoustic Recording, the Electric Recording Model, and the Super Electric Recording Model, varying in price, design and finish. The Fay Home Recorder enables anyone to make a per manent record of his or her voice, singing or speaking ; or of any broadcast music, vocal or instrumental. At the Fay Home Recorders’ Demonstration Room and Studio D.7, visitors can hear 6-in., 8-in., 10Tin. and 12-in. records made and then played back, immediately. The Milliard Wireless 221 Service Co., Ltd •) Mullard House, Charing Cross Road, London, W.C.2. The construction of Mullard, the Master Valve, demonstrated in a novel manner. OOO Yagerphone, Ltd., 28, Charlotte Street, E.C.2. Radio-Gramophones, Radio Receivers, Speakers, Radio Cabinets, Speaker Cabinets, Kits, etc. 22^ Synchrophone, Limited, 24, Berners Street, London, W.l. Combination machines (Synchrophones), including Wireless Set, Radio-gramophone and Cinematograph, the latter two being synchronised. Screens incorporating Loud Speakers for use therewith. Safety Films and Synchronised Gramophone Records for exhibition therein. Home Recording Apparatus for making gramophone records in synchrony with existing films. Gramophone Camera for making films in synchrony with existing records. 187 Stand No. Empire Hale, First loor. Memoranda. 224 Valunda Switches, “** * 28, Blomfield Road, Maida Vale, W.9. Filament and Change-over Switch, or Three-Purpose Switch : (1) On and off ; (2) Change-over ; (3) Both. Easy Fixing Accumulator Straps. I OOC Kenneth Brooks, Limited Commerce House, 72-86, Oxford Street, London, W.l. ZENITH All Mains Receivers and Radio-Gramophones. OJf* Audiovisor Ltd., 28, Little Russell Street, W.C.l Audiovisor will demonstrate the transmission of signals and sound by means of light, and the many other marvels which may be accomplished with light sensitive cells. A simple, low-priced kit for building a practical light sensitive cell unit ready to operate radio apparatus, power machines, burglar alarm, etc., will also be a feature. 227 Voltron Electric, Ltd. | ■ Queensway, Ponders End, Middlesex. Wireless Components. Kit Sets. I Complete Receivers (Battery and All-Electric). 22ft Electro Dynamic Construction Co., Ltd., Devonshire Grove, S.E.15. Silent Running Interference-free Rotary Converters for opera ting A.C. Radiograms, Receivers and Amplifiers from D.C. Mains and Batteries. A.C. to D.C. Converters. Frequency Changers and other Dynamic Machinery for Radio purposes. Battery Charging Equipments. OOQ Mains Power Radio Co., Broadway Works, Eastern Road, Romford. Rectifier Equipment, Westinghouse type. M.P.R. Chokes, Transformers, Condensers, Resistances (variable), Resist- ances (fixed), Eliminators, A.C. and D.C., with and without trickle chargers, 15, 20 and 30 m/a, Trickle Chargers, Eoud Speakers. P'2f} Dulcetto Polyphon Ltd., 2/3, Newman Street, Oxford St., London, W. 1. Radio and Radio-Gramophone Manufacturers and Factors, Wholesale distributors of Radio Receivers, Radio Acces sories, and Radio-Gramophone Accessories, Manufacturers of Dulcetto Radio-Gramophones and small or high power Gramophone Amplifiers. 188 Stand No. Empire Hall, First Floor. Memoranda. 'll] The Tonex Company, ^^ Walker Street, Blackpool, Lancs. Products shown on this Stand include : Tuning Coils for special Circuits, " Tonatuna ” Dual Wave Aerial Tuner, “ Unibox ” Dual Wave Screen Grid Coil Unit, H.F. Chokes, L.F. Trans formers, L.F. Chokes, Mains Transformers, Mains Chokes, Valve Holders, Special L.F. and Mains Transformers, Chokes and other parts for Set Manufacturers. 010 A. H. Hunt, Limited. “**-'~* H. A. H. Works, Tunstall Road, Croydon. H.T. Fuses, Stampings, Pressings and parts for the Trade, Radio Accessories, Spade Terminals, Plugs and Sockets. Oil Hunton Limited., Fitzroy Court, Tottenham Court Road, London, W. 1. Hand and Treadle Machines for punching, closing eyelets, tags, etc., single, multiple and automatic self feeding. Eyelets, Spade Tags and small fittings of all description. Sheet Metal and solid drilled Tubular Rivets, etc. 02 A Self ridge & Co., Ltd., * London, Radio Receivers. Radio Loudspeakers. Radio Accessories. Radio Components. As sold by Selfridge’s Radio Department. OIZ. The Crypto Electrical Co., Ltd. Acton Lane, Willesden, N.W.10. Crypto Radio Convertors, with cabinets and filters, for supplying Alternating current from Direct current mains for operating Receivers, Radio-Gramophones, etc. Accumulator Charging Sets of all descriptions, including a working demonstration of the Constant Potential system, from D.C. or A.C. mains. Olf. Speakeasie Home Recorders, Ltd. 24, Berners Street, London, W.l. Home Recorders, De Luxe and Junior Models. Recording Discs, double sided. Electrocolour Recording and Reproducing Needles. Aladdinite Cleaning and Lubricating Pads. Oil R- C. Radio-Electric Ltd., York House, Southampton Row, W.C.l. A range of five different types of Indoor Aerials, all fitted with improved rubber insulators. The R.C. Instant Pole Finder for determining negative pole i on any flow of current. 180 Stand No. Empire Hall, First Floor. Memoranda. Pegasus, Ltd., 10, Victoria St. Chapel Allerton, Leeds. Model 99, 5 valve Cabinet type Receiver. Model 999 the same set in Suit-case form. A new model 4 valve Screened Grid set in Suit-case form. A 2 valve Aerial set with Loud Speaker, Batteries and Mains Models. A 3 valve set similar to the above, Batteries and Mains Models. Pegasus Loud Speaker in Oak Cabinet. I I O'lQ Goodmans, 69, St* John Street Clerkenwell, E.C.l. The Exhibits comprise a complete range of Loud Speakers, Chassis, Loud Speaker Units, including exceptionally low priced Balanced Armature types, also a popular priced Cabinet Moving Coil Speaker, of the Permanent Magnet Type. Manufacturers’ requirements are especially catered for, in Loud Speaker Units, Loud Speaker Components, and Repetition work. OA() Garratt Stores, 193, Garratt Lane, Wandsworth, S.W.18. Battersea 0458. TONAX CONE ADAPTORS for building up Cone Speakers of either Single or Double-Cone type. ! OAt The Econasign Company, Ltd., 137, Victoria Street, London, S.W.l. The “ Econasign ” Printing Outfits for the production of Showcards, Notices, Price Tickets, etc., by means of trans parent stencils. Many new types will be shewn. 242 Craufurd Wireless, 24-26, Holborn, London, E.C.l. Wireless Receivers. Craufurd Patent No. 305953. OA'X Pritchard & Simpson, Ltd., ^ 13/18, Lisle Street, Newcastle-upon-Tyne. Radio Sets and Amplifiers, Commercial and Hotel Installations, Public Address Vans and Public Address Equipment. Ghas. Swain Ltd. 244 Queensway, Ponders End, Middlesex. Manufacturers of Radio Receivers, Transportable Sets, Aerial Sets. 190 Stand No. Empire Hall, First Floor. Memoranda. 24-S Gatesbys Ltd., Tottenham Court Road, London, W.l. On this Stand all Electric Sets of interest will be featured. The “ New Orbit " Screened Grid Three A.C. Mains Midget Set, made to meet the modern requirements of Broadcasting ; very selective ; will easily give a choice of Stations. The “ New Orbit ” All Electric Radio-Gramophone, an entirely new product. Very handsome Walnut finish ; a very highly efficient all-mains A.C. Screened Three Set with Inductor Motor built in, together with the latest Magnavox Mains Energised Speaker. All fittings are finished in Bronze. Portables and other Battery Sets are also exhibited, together with the New Magnavox Permanent Magnet Speaker. I Catesbys well known Easy Terms will naturally apply to other Radio Receivers which can be purchased on the Stand. Radio Society of Great Britain, Inc., 246 53, Victoria Street, London, S.W.l. Short wave apparatus for the amateur. Simple Transmitter and Receiver. Literature on Short wave working. O4.T Trade Chronicles, Ltd. ® " 6, Carmelite Street, E.C.4. Publishers of " The Radio Trade Review," a monthly trade journal for all branches of the Wireless Industry. Subscription rates, 15s. per annum. The Concordia Electric Wire Co., Ltd., 248 Trent Mills, New Sawley, nr. Nottingham. London Office & Stores: 81, Milton Street, E.C. Silk Cotton and Enamel insulated wires and strips in all colours. Litz strands. Aerial wires of every description. "Concord" flexible cords and cables. Radio cord assemblies of all types. " Connectite ” wire. High Resistance wires. Spaghetti wire wound resistances. Insulating Sleevings and materials. Public Address System Cables. The Lithanode Co., Ltd. 249 190, Queen's Road, Battersea, S.W.8. All types of free acid Unspillable Accumulators suitable for Suit-case and Transportable models. Low Tension Accumu lators in glass, celluloid and ebonite. Maximum capacity Accumulators for Radiograms and Sound equipment. The British Rola Co., Ltd. 250 Reg. Office and Works : Brondesbury Works, la, Willesden Lane, London, N.W.6. (Maida Valo 5061). Head Office: 24-26, Maddox Street, London, W.l. A complete exhibit of the new British-made Rola Moving-Coil Speaker Units in both permanent magnet and A.C. or D.C. field-excited models. Special attention is directed towards Model F midget type units, which are admirably suited for use in the home or for multiple speaker installations. Also towards the permanent magnet models, which have been developed as the result of a very considerable amount of research. Demonstration Room No. D 10. 191 ’ ] ' I The Primus Manufacturing Co. “Primus House,” Willow Street, London, E.C.2. ; « Pioneers of Good Dry Batteries i for Wireless Application. ! ( Visit us at STAND 193 .» or ’phone Bishopsgate 5681. ‘ ! ■ Export Enquiries particularly solicited. ' 1 ” i 7 Makers of the “Primus Autocel, Koh-I-Noor” : and other well-known Brands. ? r l The 1 l MAINS UNIT t with the « 3 Years’ Guarantee ! ! After only 12 months’ production ■ Heayberd are able to announce a I signed Three Years’ Warrant ■ t against Breakdown with all their E Model C. Mains Units. This ■ V Olympia revelation is striking I evidence of the faith held in these ■ Units, which have achieved such I l tremendous popularity. efl ] 1 There is a Unit suitable for 1 l your particular Receiver. Call EXAMPLE KIT at our Stand and let us show it to you. Model C.150 Outputs: 25 ma. at 150 volts or Stand 25 ma. at 120 volts Three tappings—one » variable. Westing- house rectification. 68 Assembled in Hand some Case. Requires AYBER wiring-up only.. Empire Simplified Point-to- Point diagram. Hall J F. C. HEAYBERD & CO., PRICE - 76/- lO, Finsbury St., London, E.C.2. 192 Stand No. Empire H all, First Floor. Memoranda. 2^1 Dayzite, Ltd. ^^ 17, Lisle Street, Leicester Square, W.C.2. Here can be seen all the latest Standard makes of Wireless Receiving sets and general Components. Direct wholesale agents for Marconi, McMichael, Pye, General Electric Co., etc., etc. Members of the B.R.V.M.A. and hold large stocks of all the latest types of valves. Distributing agents for the Musikon Sound on Film System Talking Picture. Sound on Film Heads, for Portable and fixed apparatus, Pack Amplifiers, Logarithmic Horns and Units. Light Cells and Exciter Lamps. Latest types of Radiograms, Portable Sets and the new Brown " Microbox ” Electrical Pick-up. 2^2 Eastick & Sons, Eelex House. 118, Bunhill Row, E.C.l. All " Eelex " plugs, terminals, spades, pins and sockets are made in various colours and are interchangeable. Something which should be in every man's pocket—Eelex Testing Prods—absolutely indispensable. Two ends of a wireless set—an “ Eelex ” earth bowl and an “ Eelex " safety switch—both vital necessities. “ Eelex ” Frame aerial adaptable for any receiver, Dual range—200, 000, 900, 2,000 metres. " Eelex ” short wave convertor (15/60 metres) makes any receiver a super-het. The Short-wave world at your feet. Byldurone Cabinets—The finishing touch. 2^T Department of Overseas Trade, 35, Old Queen Street, London, S.W.l. British manufacturers and traders can obtain from the Dept, of Overseas Trade reliable commercial information relative to markets abroad. Information can be obtained regarding : Overseas demand for particular goods, methods of marketing and distribution, and the nature of the competition ; customs tariffs and regulations ; registration of trade marks, statistics of imports and exports ; shipping and transport; sources of raw material and of goods not manufactured in the United Kingdom; importers of various goods in overseas markets, and concerns prepared to act as agents for British manu facturers. Trade Fairs and exhibitions of foreign goods and catalogues are arranged for the guidance of British manu facturers producing competitive articles. All Standholders are invited to consult the Department's representative on the Stand. British “Wireless for the Blind” Fund, 254 226, Great Portland Street, London, W.l. LET THE BLIND HEAR. The British “ Wireless for the Blind ” Fund desires to thank all listeners who have responded to the broadcast appeals during the past eighteen months, and who have therefore helped to supply 17,000 wireless sets to the blind in Great Britain and Northern Ireland. Only £4,000 still required. Please visit our Stand at this Exhibition or send your re mittance to the Right Hon. R. McKenna, 226, Great. Port- f land Street, London, W.l. OCC G. Mellor, 154, Kings Cross Road, W.C.l. GENERAL RADIO FACTOR. 193 Hall, First Floor. Mxmorakda. Stand No. Empire Rolls Radio, Ltd., 256 138, St. John Street, E.C.l. Radio Gramophones; Portable Receivers; Moving Coil Speakers ; Mains Transformers; Power Amplifiers. — ; NATIONAL HALL: FIRST FLOOR DEMONSTRATION ROOMS. s Room No. Lotus Radio, Ltd • > D 1 Lotus Works, Mill Lane, Old Swan, Liverpool. ' This demonstration room will be used for the demonstration of LOTUS Mains Receivers, full particulars of which are i set out under Stand No. 23. The Radio Gramophone, which embodies the same chassis as The Table Console model receiver, will also be demonstrated, together with the full range of the LOTUS products. ColumbiaGraphophoneCo., Ltd., ** 98-108, Clerkenwell Road, E.C.l. Demonstrations of the following : Radio Receivers (Table, Portable and Pedestal). Speakers (Moving Coil and Cone). Radio-Graphophones. Electro-Graphophone. I T~) 1 Marconiphone Co., Ltd., i Radio House, Tottenham Court Road, W.l. At last year s Exhibition. The Marconiphone Company gained a big reputation for their entirely novel and original form of demonstration, which proved to be one of the biggest attractions to all visitors to the Show. At this year’s Exhibition, the Company are staging an even more ingenious demonstration of their various models. Ample seating accommodation is provided, and performances will be given at every hour and half hour, the doors being closed during each session, so that the audience may listen undisturbed and in comfort. All visitors to Olympia who enjoy an 'interesting musical entertainment, presented in a new and intriguing form and combined with an element of mystery, should make a point of visiting the Marconiphone Demonstration Hall. T) A E. K. Cole, Ltd., ■ EKCO Works, Southend-on-Sea. EKCO ALL-ELECTRIC RADIO. All-Electric Radiograms for D.C. and A.C. Mains. All-Electric Radio-Consoles for D.C. and A.C. Mains. All-Electric Receivers for D.C. and A.C. Mains. Combined All-Power Supply Units for A.C. Mains. Combined H.T. and L.T. Charger Units for A.C. Mains. Trickle Charger for A.C. Mains. Home Recorders. " EKCO " Radiocorder. H.T. Units for A.C. and D.C. Mains. I 194 Room No. National Hall, First Floor. Memoranda. "T) C Kolster-Brandes, Limited, ^ Cray Works, Sidcup, Kent. In Demonstration Room D5, Kolster-Brandes, Ltd., will give continuous demonstrations of their range of Radio Gramo phones, Loud Speakers and Radio Receivers working from the common input and from gramophone records, including the following :— K.B.283. 3 valve Radio-Gramophone. Kolster 6 valve Super Heterodyne Receiver. K.B. 279. 3 valve A.C. Mains Receiver. K.B. 281. 3 valve Battery Receiver. Kobra 3 valve Battery Receiver. Kobra Junior 3 valve Battery Receiver. K.B. Battery “ Pup.” K.B. Electric “ Pup.” K.B. Portable Receiver. K.B. 72 Speaker. K.B. 232 Speaker. K.B. 287 Speaker. /C Lissen, Limited. ^ Lissenium Works, Worple Road, Isleworth, Mddx. Lissen Ltd., will be giving continuous demonstrations in Room D.6. This demonstration room will be furnished with Radiogramo phones, Receivers, and Loud Speakers as exhibited on their Stand. Radiogramophones of various sizes and types will be on view, including several new designs in addition to models which are already extremely popular. Among the Receivers will be found the Lissen two, three and four Valve Cabinet and Transportable instruments, operated from Mains or Batteries. A demonstration of the new Screen Grid Receiver and Radio- Gramophone alone will well repay a visit to the Exhibition. 7 “Fay” Home Recorders, Ltd., 121, Victoria Street, Westminster, S.W.l. In the “ Fay ” Home Recorders Demonstration Room and Studio visitors may hear 6-in., 8-in., 10-in. and 12-in. records made, and then played back immediately. The full range of Fay Home Recorders may also be seen on Stand 220 in the Empire Hall. T’’) Q General Electric Co., Ltd.•> ^ Magnet House, Kingsway, London, W.C.2. G.E.C. Radio, embracing GECoPHONE Receiving Sets, Loud Speakers and OS RAM Valves, will be the subject of a very interesting film to be shown at intervals during the course of the Exhibition. The complete range of GECoPHONE Radio Receivers and Loud Speakers will be on view, and visitors to this Demon stration Room will also have an opportunity of hearing a demonstration of the new GECoPHONE Radio-Gramophone, the new GECoPHONE Inductor Dynamic Loud Speaker, and the new GECoPHONE Cabinet Moving-Coil Loud Speaker. The GECoPHONE Power Amplifying Equipment will be used for announcements. 195 I Room No. National Hall, First Flo on. Memoranda. Q Celestion, Ltd., S London Road, Kingston-on-Thames. Those interested in quality reproduction will find the new Celestion range of loud speakers, which will be demonstrated in Room D 9, of unusual interest. Both the cabinet and chassis models will be on view, together with the W5 Pick-up, and in each case the design shows a quality which has become associated with the name “ Celestion. The Cabinet models are the M 12, in Walnut finish, and the M 14, the senior model of the same type. For the Home Constructor there is the M 12 cone chassis. In the Moving-Coil range, the R.P.M 12 and R.P.M 8 are available. The D 10, D 12 and Z 20, three of last season’s models, are being continued. T\ i n The British Rola Go., Ltd. -*-V/ Reg. Office and Works: Brondesbury Works, la, Willesden Lane, London, N.W.6. (Maida Vale 5061.) Head Office: 24-26, Maddox Street, London, W.l. A complete exhibit of the new British-made Rola Moving-Coil Speaker Units in both permanent magnet and A.C. or D.C. field-excited models. Special attention is directed towards Model F midget type units, which are admirably suited for use in the home or for multiple speaker installations. Also i towards the permanent magnet models, which have been developed as the result of a very considerable amount of research. ■ T) 1 1 Ready Radio, Ltd., X 159, Borough High Street, London Bridge, S.E.l Office & Works; Eastnor House, Blackheath, S.E.3 Examples of sets described by well-known designers and published in the journals. i Demonstrations of the Instamat output transformer. L. McMichael, Ltd., D14 Radio Engineers, London and Slough. In Demonstration Room D14 Messrs. L- McMichael, Ltd., will give continuous demonstrations of the instruments of their manufacture, by means of gramophone records, and by the common input provided by the Exhibition Organisers. The instruments demonstrated will include Radio Gramo phones, Moving Coil Speakers, and the full range of McMichael : radio products. ’ IDG Room No. NaI'ionaL Hall, First Floor. Memoranda. 1 C Radio Gramophone Development ^ 10 Co., Ltd •) 18/20, Frederick Street, Birmingham. “ RGD ” De Luxe Radiogramophone type A.C.S6. D.C.S6. 2 screen grid valves, band pass tuning, single control tuning, 10 watt output stage tone control. “ RGD " Super Radiogramophone. 7 valve super heterodyne chassis with single control tuning, medium and long wave bands, band pass tuning, 10 or 50 watt output stage. “ RGD " Popular Radiogramophone. Type A.C.P4. D.C.P4. 2 screen grid valves, single control tuning, tone control, 10 watt super power output stage with moving coil loud speaker and walnut cabinet. " RGD " 4 valve Radio type PR.4. 2 screen grid valves, single control tuning, super power output stage with moving coil loud speaker and walnut cabinet. “ RGD" Super heterodyne short wave convertor enabling short waves 15-100 metres to be received. “ RGD ” Pickups, speakers, amplifiers, etc. D 1 ft Synchrophone, Limited. 24, Berners Street, London, W.l. Demonstrations of the Synchrophone, combination machines including Wireless Set, Radio-Gramophone and Cine matograph. Screens, incorporating loud speakers, safety films and synchronised gramophone records for use there with, and home recording apparatus will be on view, together with a gramophone camera for making films in synchrony with existing records. T') 1 7 Speakeasie Home Recorders, Ltd. ■ 24, Berners Street, London, W.l. I11 Room D 17 there will be given demonstrations of the range of apparatus marketed by Speakeasie Home Recorders, Ltd., including the De Luxe and J unior Models, which are supplied complete in box with diamond needle. Electrocolour recording and reproducing needles will also be displayed together with Aladdinite combined cleaning and lubricating pads. F)1Q IQ Ultra Electric, Ltd., U Erskine Rd., Chalk Farm, N.W.3. Continuous demonstrations of the Ultra All-Electric Radio Receivers and Moving Coil and Air Chrome Speakers : Twin Cub. Tiger Three. Panther Four. Ultra All-Electric Consolettes : Tiger III Consolette. Panther IV Consolette. The full range of Ultra Moving Coil Speakers and the Ultra Air Chrome Double-Linen Diaphragm Speaker will be used for these auditions. 197 1 & 0 0 0 P 1 1 I Artists in FI ora i 0 Decoration = 0 a a a if 0 a a i STROUD BROS. Ltd. 0 a a «6 I8£ Green Lanes 0 a Lend on, N. 4 a ss 0 a a s 0 a Official Contractors to National Radio a m Exhibition and other London and Provincial m Exhibitions, Principal Theatres, Hotels and Cinemas. m m Enquiries » «* Phone North 0882»3 & 198 Room No. National Hall, First Floor. Memoranda. F') OA S. A. Lamplugh Ltd., Little Park Street, Coventry. Continuous demonstrations of the Silver Ghost Inductor Dynamic Speaker, Chassis and Cabinet Models. “ INDUCTASET ” All Electric Set Demonstration by Pick-up from Gramophone Records. Varley w A (Proprietors: Oliver Pell Control Ltd.), Kingsway House, 103, Kingsway, London, W.C.2. An entirely new range of All-Electric Receivers and Radio- Gramophones for A.C. or D.C. Mains, embodying the Square Peak Band-Pass principle, will be on view. The receivers include 3 and 4 valve models, all with built-in moving coil speakers. Demonstrations will be given by means of the common input and by reproduction of gramophone records. The British Blue Spot Company Ltd., D 22 Blue Spot House, 94/96, Rosoman Street, London, E.C.l. Loudspeaker Units and Chassis. Inductor Type Unit with chassis. Complete Loud Speakers. Mains Disturbance Eliminator. Rejector Wave Trap. Permanent Magnet Loud Speaker with Transformer. Moving Coil D.C. Energised model with Transformer. All Mains Receivers. Bakers Selhurst Radio, D 23 42, Cherry Orchard Road, East Croydon. Moving Coil Loud Speakers. Permanent and Electro Magnets. Cinema Equipment. TA 24 The Marconiphone Co., Ltd. A' w I Racjio House, Tottenham Court Road, W.l. For particulars of Demonstrations, see under Demonstration Room D 3. T") OC Edison Bell, Ltd., ^ Glengall Road. Edison Bell Ltd., will demonstrate in their Demonstration Room apparatus of their manufacture, as follows :— Radiogramophones. Twin Turntable Amplifying Apparatus. Adaptable Gramophone Units. Pickup Units. Speakers. Visitors to the Exhibition, after inspecting the goods on the Edison Bell Stand Number 41 are recommended to hear them in actual operation in this Demonstration Room. 199 The Radio Manufacturers' Association . LIST OF MEMBERS. A. E. F. Manufacturing Co. Ohmic Works, Queensway, Pondera End, Mddx. Auto Electric Devices Ltd. Diamond Works, Brighton, Sussex. Automatic Coil Winder & Elec trical Equipment Co. Ltd. ... Winder House, Douglas Street, S.W.l. B. M. & A. Ltd. ... Wilmslow, Manchester. Baker, A...... 89, Selhurst Road, S. Norwood, S.E.25. Baird Television, Ltd. ... 133, Long Aero, W.C.2. Bayliss, Ltd., William ... Islington Tube Works, Sheepcote Street, Bir mingham. Belling & Lee, Ltd. . Queensway Works, Ponders End, Middlesex. Benjamin Electric, Ltd. .. Brantwood Works, Tariff Road, Tottenham, N.17. Biafone Co., Ltd., The .. Gosford Road, Beccles, Suffolk. Bird & Sons, Ltd., Sydney S. .. Sarnesfield Road, Enfield Town, Middlesex. Bligh, S. W...... 1/2, North Lane, Canterbury. British Ebonite Co., Ltd...... Nightingale Road, Hanwell, W.7. British Hard Rubber Co., Ltd. ... Wharf Road Works, Ponders End, Middlesex, British Ideal Patents, Ltd. .. Green Street, Brimsdown, Middlesex. British General Mfg. Co., Ltd. ... Brockley Works, Brockley, S.E.4. British Radio Gramophone Co.,Ltd. 77, City Road, E.C.l. British Radiophone, Ltd...... Aldwych Houso, Aldwych, W.C.2. British Thomson - Houston Co., Ltd., The ...... Crown House, Aldwych, W.C.2. Brownie Wireless Co. of Great Britain, Ltd...... Nelson Street Works, Mornington Crescent, N.W.l. Bulgin & Co., Ltd., A. F...... Abbey Road, Barking, Essex. Bullphone, Ltd...... 38, Holywell Lane, E.C.2. Burton, C. F. & H...... Progress Works, Bernard Street, Walsall. Burne-Jones & Co., Ltd...... 296, Borough High Street, S.E.i. Carrington Mfg. Co., Ltd. ... 24, Hatton Garden, E.C.l. Celestion Ltd. ... London Road, Kingston-on-Thames. Chloride Electrical Storage Co., Ltd. ... 217/229, Shaftesbury Avenue, W.C.2. Clarke & Co. (Manchester), Ltd.,H. Atlas Works, Eastnor Street, Old Trafford, Man chester. Climax Radio Electric, Ltd. ... Haverstock Works, Parkhill Road, Hampstead, N.W.3. Cole, Ltd., E. K. ... “ Ekco ” Works, Southend-on-Sea. Collinson’s Precision Screw Co., Provost Works, Macdonald Road, Walthamstow, Ltd...... E.17. Columbia Graphophone Co., Ltd. ... 92, Clerkenwell Road, E.C.l. Colvern, Ltd. ... Mawneys Road, Romford, Essex. Cossor, Ltd., A. C...... Cossor House, Highbury Grove, N.5. Craufurd Wireless ...... National Works, High Road, Leyton. Darwins, Ltd...... Fitzwilliam Works, Sheffield. De la Rue & Co., Ltd., Thos. ... 90, Shernhall Street, Walthamstow, E.17. Dibben & Sons, Ltd., William ... Antelope Bldgs., St. Mary’s Road, Southampton. Downing & Sons, Ltd., John S. ... Crown Works, Commercial Street, Birmingham. Dubilier Condenser Co. (1925), Ltd. ... Ducon Works, Victoria Road, North Acton, W.3. Dyson & Co. (Works), Ltd., J. ... 5, Godwin Street, Bradford. 200 (Continued on next paye.) List of Members of The Radio Manufacturers’ Association—(continued). Eagle Engineering Co., Ltd., The Eagle Works, Warwick. Eastern Wireless Co., Ltd. ... California Works, Brighton Rd., Belmont, Surrey, Edison Bell, Ltd...... Edison Bell Works, Glengall Road, S.E.15. Edison Swan Electric Co.,Ltd.,The 155, Charing Cross Road, W.C.2. Electrical & Radio Products (1931), Ltd...... Empire Works, Salfords, Redhill, Surrey. Electrical Devices Co. ... 12, Great James Street, Bedford Row, W.C.l. Ellison Manufacturing Co., Ltd. Dragon Works, Harrogate. Epoch Radio Mfg. Co., Ltd. ... 3, Farringdon Avenue, E.C.4. Ever Ready Co. (Gt. Britain), Ltd. Ever Ready Works, Hercules Place, Holloway, N.7. Falk Stadelmann & Co., Ltd. ... 83-93, Farringdon Road, London, E.C.l. Faraday Sound Wave Electric Gramophone, Ltd. ... 8, Bridewell Place, E.C.4. Ferranti, Ltd. ... Hollinwood, Lancashire. Formo Company, The ... 23, Golden Square, Piccadilly Circus, W.l. Fuller Accumulator Co. (1926) Ltd. ... Woodland Works, Chadwell Heath, Essex. Gambrell Radio, Ltd. ... Buckingham House, Buckingham Street, Strand, W.C.2. Garnetts ... Gresley Radio Works, Ordsall Lane, Salford, Manchester. General Electric Co., Ltd., The ... Magnet House, Kingsway, W.C.2. Gould, Harper & Co., Ltd. ... Fleets Bridge, Upton Road, Poole, Dorset. Graham Amplion, Ltd. ... St. Andrew’s Works, Slough, Bucks. Graham-Farish, Ltd. ... 163, Masons Hill, Bromley, Kent. Gramo-Radio, Ltd...... Commercial Works, Blackburn Road, Church, Lancs. Gripso Co...... 32, Victoria Street, S.W.l. Grosvenor Electric Batteries Ltd. 2-3, White Street, E.C.2. H. & B. Radio Co...... 34-38, Beak Street, W.l. H.S.P. Wireless Co...... Langford Works, Weston-Super-Mare. Hacker & Sons, H...... Perfecta Works, Ray Lea Road, Maidenhead. Halcyon Wireless Co., Ltd., The 27a, Pembridge Villas, Notting Hill Gate, W.ll. Hardyson Radio, Ltd. ... C/r. St. Andrews Road & Leeds Road, Huddersfield. Hart Bros. Electrical Mfg. Co., Ltd...... 4, Queensway, Ponders End, Middlesex. Hart Collins, Ltd...... 38a, Bessborough Street, S.W.l. Holt & Crompton ...... 196, Shaftesbury Avenue, W.C.2. Hustler, Simpson & Webb, Ltd. ... 55/57, Tanner Street, Bermondsey, S.E.l. Igranic Electric Co., Ltd. ... 147, Queen Victoria Street, E.C.4. Jackson Bros. ... 72, St. Thomas Street, S.E.l. Jewel Pen Co., Ltd. ... 21-22, Gt. Sutton Street, London, E.C.l. Junit Manufacturing Co., Ltd. ... 2, Ravonscourt Square, W.6. ... Cray Works, Sidcup, Kent. I Kolster-Brandes, Ltd. Lamplugh, Ltd., S. A. ... 89, Little Park Street, Coventry. Lectro-Linx, Ltd...... 254, Vauxhall Bridge Road, S.W.l. Lissen, Ltd...... Lissenium Works, Worplo Road, Isleworth, Mddx. Limit Radio, Ltd...... 15-29, Windsor Street, Essex Road, N.l. Lock, Ltd., W. & T. ... St. Peter’s Works, Bath. London Electric Wire Co. & Smithsw, Ltd...... Playhouse Yard, Golden Lane, E.C.l. Lotus Radio, Ltd...... Lotus Works, Mill Lane, Old Swan, Liverpool. M.P.A. Wireless (1930), Ltd. ... 62, Conduit Street, W.l. Magnavox (Great Britain) Ltd. ... 89, Kingsway, W.C.2. Magneto, Accumulator & Electro plating Co...... Leafield Works, Leafield Road, Dumfries. Marconiphone Co., Ltd...... 210/212, Tottenham Court Rd., W.l. McMichael, Ltd., L...... Woxham Road, Slough, Bucks. Mel-Price Radio ...... Symphony Works, Stewart St., Wolverhampton. Montague Radio Inventions & Beethoven Works, Great College St., Camden Development Co., Ltd. Town, N.W. Mullard Radio Valve Co., Ltd Mullard House, Charing Cross Road, W.C.2. Mdrphy Radio, Ltd. Broadwater Road, Welwyn Garden City, Herts. 201 (Continued on next page.) List of Members of The Radio Manufacturers' Association—(continued). National Accumulator Co,, Ltd. ... 50, Grosvonor Gardens, S.W.l. New London Electron Works, Ltd. ... East Ham, E.6. - O. & S. Oilless Bearing Co., Ltd.... 88, Victoria Road, Willesden, N.W.10. r Oldham & Son, Ltd...... Denton, Manchester. Oliver Pell Control, Ltd. Kingsway House, 103, Kingsway, W.C.2. Ormond Engineering Co., Ltd. Ormond House, Rosebery Avenue, E.C.l. Osborn, C. A...... Regent Works, Arlington Street, N.l. Park Electric Radio Productions, Ltd...... Park Royal Road, North Acton, N.W.10. Partridge & Mee, Ltd. ... 74, New Oxford Street, W.C.l. Partridge Wilson & Co. ... Davenset Works, Evington Valley Road, Leicester. Perfectavox, Ltd...... Alexandra Works, High Street, Yeadon, nr. Leeds. Pertrix, Ltd...... 233, Shaftesbury Avenue, W.C.2. Pritchard & Simpson ... 13*18, Lisle Street, Newcastle-on-Tyne. Pye Radio, Ltd. ... Radio Works, Cambridge. Radio Gramophone Development Co., Ltd...... 18-20, Frederick Street, Birmingham. Radio Instruments, Ltd...... Purley Way, Croydon, Surrey. Rawswood Electrical Co...... Preston New Road, Blackpool. Ready Radio, Ltd. ... 41, Newcomen Street, London Bridge, S.E.l. Redfern’s Rubber Works, Ltd, ... Hyde, Cheshire. Red Star Radio, Ltd. ... Aston Road, Birmingham. Rees, Mace Mfg. Co., Ltd...... 39a, Welbeck Street, W.l. Regent Radio Supply Co...... 21, Bartlett’s Buildings, Holborn Circus, E.C.4. Rist (1927), Ltd., A...... Waveney Works, Freemantle Road, Lowestoft. Rolls Radio, Ltd...... 138, St. John Street, Clerkenwell, E.C.l. Rooke Bros., Ltd...... 32, Queensway, Ponders End. Siemens Electric Lamps & Supplies Ltd...... Caxton House, Westminster, London, S.W.l. Six-Sixty Radio Co., Ltd. ... 17-18, Rathbone Place, W.l. Smurthwaite, F. W...... 16a, Onslow Gardens, Wallington, Surrey. Sovereign Produots, Ltd. ... 52/54, Rosebery Avenue, Clerkenwell, E.C. 1. Standard Battery Co. ... 184-188, Shaftesbury Avenue, W.C. Standard Telephones & Cables, Ltd...... Connaught House, Aldwych, W.C.2. Stratton & Co., Ltd. ... Balmoral Works, Bromsgrove Street, Birmingham. Swift Leviok & Sons, Ltd. ... Clarence Steel Works, Sheffield. Synchrophone, Ltd ... 24, Berners Street, W.l. Tannoy Products ... 1-7, Dalton Street, West Norwood, S.E.27. Telegraph Condenser Co., Ltd. ... Wales Farm Road, N. Acton, W.3. Telsen Electric Co., Ltd. ... Thomas Street, Aston, Birmingham. Tudor Accumulator Co.. Ltd., The 2, Norfolk Street, Strand, W.C.2. Turner & Co. ... 54, Station Road, New Southgate, N.ll. Ultra Electric, Ltd. ... Erskine Road, N.W.3. Umello Ltd...... 56, Great Marlborough Street, W.l. Vandervell & Co., Ltd., C. A. ... 319, Regent Street, W.l. Voltron Electric, Ltd...... Queensway, Ponders End, Middlesex. Watmel Wireless Co., Ltd. ... Imperial Works, High Street, Edgware, Middlesex. Webb Condenser Co., Ltd. ... 42, Hatton Garden, E.C.l. We8tinghouse Brake & Saxby Signal Co., Ltd...... 82, York Road, King’s Cross, N.l. Whiteley Electrical Radio Co., X/td...... Nottingham Road, Mansfield, Notts. Whittingham, Smith & Co...... Portadyne Works, Gorst Road, N.W.10. Wilkins & Wright, Ltd...... Utility Works, Holyhead Road, Birmingham. Wingbove & Rogers, Ltd...... Mill Lane, Old Swan, Liverpool. Wright & Weaire, Ltd...... 740, High Road, N.17. Charlotte Cabinet Works, Ponders End, Middx. Yagerphone Ltd. 202 1 5 i CLASSIFIED DIRECTORY OF EXHIBITS. STAND NO. STAND NO. Accumulators. Batteries, Wet. C.A.V. Batteries, Ltd. 91 Standard Battery Co. 94 Chloride Electrical Storage Co., Ltd. S Ever Ready Co. (Gt. Britain), Ltd.... 76 Fuller Accumulator Co. (1926), Ltd. 36 Battery Clips. Lisscn, Ltd. 17 Bulgin & Co., Ltd., A. F. ... 102 Lithanode Co., Ltd...... 249 Burton, C. F. & H. ... 31 National Accumulator Co., Ltd. Gripso Co...... 8115 Oldham & Son, Ltd. ... 66 Pertrix, Ltd. ... 39 Brackets. Radio Service (London), Ltd. ... 162 Siemens Electric Lamps & Supplies, Burton, C. F. & H. ... 31 Ltd...... 74 Lectro Linx, Ltd. 202 Lissen, Ltd. 17 Accumulator Charging Plant. : Brown Brothers, Ltd. ... 105 Cabinets. Crypto Electrical Co., Ltd...... 235 Burton, C. F. & H...... 31 Electrical & Radio Products (1931), Calders, Ltd...... 183 Ltd...... 3 Carrington Manufacturing Co., Ltd 51 ! Electro-Dynamic Construction Co., Downing & Sons, Ltd., John S. 54 ! Ltd...... 228 Eastick & Sons, J. J. 252 ! Greatrex & Co., R. G. 197 Lock, Ltd., W. & T. ... 160 Partridge Wilson & Co. 43 Ormond Engineering Co., Ltd. 34 Westinghouse Brake & Saxby Signal Osborn, Chas. A. 205 Co., Ltd...... 44 Yagerphone, Ltd. 222 Aerials and Aerial Equipment. Castings. Concordia Electric Wire Co., Ltd. ... 248 Danipad Rubber Co., Ltd. ... 70 Lissen, Ltd. 17 Eastick & Sons, J. J. ... 252 London Electric Wire Co. & Smiths, Cells, Light Sensitive. Ltd...... 27 Audiovisor, Ltd. ... 226 New London Electron Works, Ltd.... 35 Peto Scott Co., Ltd. ... 179 P. R. Products 1S7 Chokes. R. C. Radio Electric, Ltd. ... 237 British General Mfg. Co., Ltd. 30 Wright & Weaire, Ltd. ... 152 Bulgin & Co., Ltd., A. F...... 102 Burton, C. F. & H. ... 31 Amplifiers. Clarke & Co. (M/c), Ltd., H. 33 Ardiug & Hobbs, Ltd. ... 171 Climax Radio Electric, Ltd. 42 Edison Bell, Ltd...... 41 Danipad Rubber Co., Ltd. ... 70 Igranic Electric Co., Ltd. 28 Dubilier Condenser Co. (1925), Ltd. 92 Mains Radio Gramophones, Ltd. 53 Dyson & Co. (Works), Ltd., J. 78 Partridge & Mce, Ltd. 177 Graham-Farish, Ltd.... 32 Radio Gramophone Development Co. Igranic Electric Co., Ltd. 28 Ltd. ... 11 Junit Mfg. Co., Ltd. ... 97 Rolls Radio, Ltd. 256 Lissen, Ltd. 17 Smurthwaite, F. W. ... 107 London Electric Wire Co. & Smiths, Tannoy Products ...... 63 Ltd...... 27 Lotus Radio, Ltd. 23 Automatic Gramophone Stops. Mains Power Radio Co. 229 Oliver Pell Control, Ltd. (Varley) 5S Electric G ramophones, Ltd. 89 Ormond Engineering Co., Ltd. 34 Paroussi, E. 158 Batteries, Dry. Partridge & Mee, Ltd. 177 Adie & Co., Ltd. ... 169 Radio Instruments, Ltd. 29 Chloride Electrical Storage Co., Ltd. 8 Rcgentonc, Ltd...... 22 Electrical & Radio Products (1931), Rookc Bros., Ltd...... 79 Ltd. . 3 Sovereign Products, Ltd. 64 Ever Ready Co. (Gt. Britain), Ltd 76 Taylor, Ltd., Henry E. 212 Falk Stadelmann & Co., Ltd. 87 Tciscn Electric Co., Ltd. 19 Fuller Accumulator (1926), Ltd. 36 Tonex Co...... 231 Grosvenor Electric Batteries, Ltd. 72 Turner & Co. ... 82 Lissen, Ltd...... 17 Watmel Wireless Co., Ltd. ... 100 Marconiphone Co., Ltd. 4 Wright & Weaire, Ltd. ... 152 Oldham & Son, Ltd., 66 Ormond Engineering Co., Ltd. 34 Pertrix, Ltd. ... 39 Cinema Equipment. Primus Manufacturing Co., Ltd. ... 193 Bakers Selhurst Radio ... 216 Siemens Electric Lamps & Supples, Dayzite, Ltd...... 251 Ltd. ... 74 Igranic Electric Co., Ltd. 2S 203 {Continued on next page,) Classified Directory of Exhibits (continued). STAND NO. STAND NO. Coils, Tuners, etc. Cone Adaptors. British General Mfg. Co., Ltd. 30 Carratt Stores. ... 240 Bulgin & Co., Ltd., A. F...... 102 Colvern, Ltd...... 3S Dnnipad Rubber Co., Ltd...... 70 Converters. Dyson & Co. (Works), Ltd., J. 78 C. A. V. Batteries, Ltd. 91 Formo Co...... 61 Crypto Electrical Co., Ltd. ... 235 Lissen, Ltd. 17 Electro-Dynamic Construction Co., London Electric Wire Co. & Smith Ltd...... ; 228 Ltd...... 27 Standard Battery Co. 94 Lotus Radio, Ltd. 23 Oliver Pell Control, Ltd. (Varley) 5S Cords, Flexible. Paroussi, E. ... 158 P. R. Products ...... 1S7 Belling & Lee, Ltd. ... 13 Rooke Bros., Ltd...... 79 Burton, C. F. & H...... 31 Sovereign Products, Ltd. 64 London Electric Wire Co. & Smiths, Telsen Electric Co., Ltd. 19 Ltd...... 27 Tonex Co. 231 Turner & Co. ... 82 Coupling Units. Watmel Wireless Co., Ltd. ... . 100 Wright & Weaire, Ltd. . 152 Colvern, Ltd...... 38 Dubilier Condenser Co. (1925), Ltd 92 Coil Formers. Graham-Farish, Ltd...... 32 Lamplugli, Ltd., S. A. 168 Clarke & Co. (M/c), Ltd., H. 33 Lissen, Ltd. 17 Danipad Rubber Co., Ltd. ... 70 58 Peto Scott Co., Ltd...... 179 Oliver Pell Control, Ltd. (Varley) Ormond Engineering Co., Ltd. 34 Redferns Rubber Works, Ltd. 163 Sovereign Products, Ltd. 64 Wright & Weaire, Ltd. 152 Crystal Detectors and Crystal Set Accessories. Brownie Wireless Co. of G.B., Ltd. ... 37 Coil Holders. Graham & Co., R. F...... 189 Danipad Rubber Co., Ltd. ... 70 Jewel Pen Co., Ltd...... 156 Lissen Ltd...... 17 Ormond Engineering Co., Ltd. 34 London Electric Wire Co., & Smiths, Ltd...... 27 Ormond Engineering Co., Ltd. 34 Deaf, Appliances for. Rooke Bros, Ltd...... 79 Igranic Electric Co., Ltd 28 Coil Winding Machines. Dials, Knobs, etc. Automatic Coil Winder & Electrical Equipment Co., Ltd. ... 207 Bird & Sons, Ltd., Sydney S. 172 Brownie Wireless Co. of G.B., Ltd. 37 Condensers, Fixed and Variable. Burton, C. F. & H...... 31 Danipad Rubber Co., Ltd. ... 70 Bird & Sons, Ltd., S. S. ... 172 Ormond Engineering Co., Ltd. 34 British Radiophone, Ltd. 155 Paroussi, E...... 158 Bulgin & Co., Ltd., A. F. 102 Taylor, Ltd., Henry E. 212 Burton, C. F. & H...... 31 Telsen Electric Co., Ltd. 19 Colvern, Ltd...... 38 Wilkins & Wright, Ltd. 90 Danipad Rubber Co., Ltd. ... 70 Dubilier Condenser Co. (1925), Ltd 92 Edison Bell, Ltd...... 41 Eyeletting Machines. Formo Co...... 61 Hunton, Ltd...... 233 Graham Farish, Ltd...... 32 Igranic Electric Co., Ltd. 28 Jackson Bros...... 62 Earth Tubes, etc. Lissen, Ltd...... 17 Climax Radio Electric, Ltd. 42 London Electric Wire Co. & Smiths, Dyson & Co. (Works), Ltd., J. 78 Ltd. 27 Eastick & Sons, J. J. 252 Lotus Radio, Ltd. 23 New London Electron Works, Ltd. 35 Mains Power Radio Co. 229 Wright & Weaire, Ltd...... 152 Ormond Engineering Co., Ltd 34 Paroussi, E...... 158 Peto Scott Co., Ltd...... 179 Ebonite. Rooke Bros., Ltd...... 79 British Ebonite Co., Ltd. ... 153 Six-Sixty Radio Co., Ltd. .. 20 British Hard Rubber Co., Ltd. 182 Standard Battery Co. 94 Danipad Rubber Co., Ltd. ... 70 Sovereign Products, Ltd. 64 Redferns Rubber Works, Ltd. ... 163 Telegraph Condenser Co., Ltd. 14 Telsen Electric Co., Ltd. 19 Electrical Gramophones. Watmel Wireless Co., Ltd. 100 Wilkins & Wright, Ltd. 90 Auto Electric Devices, Ltd...... 159 Wingrove & Rogers, Ltd. 60 Columbia Graphoplione Co., Ltd. ... 7 204 (Continued on next payc.) Classified Directory of Exhibits (continued). STAND NO. STAND NO. Eliminators and Mains Equipment. Grid Leaks. Bullplione, Ltd...... 12 Bulgin & Co.# Ltd., A. F. 102 Burton, C. F. & H...... 31 Danipad Rubber Co., Ltd. ... 70 Clarke & Co. (M/c.), Ltd., H. 33 Dubilier Condenser Co. (1925), Ltd. 92 Climax Radio Electric, Ltd. 42 Lissen, Ltd...... 17 Cole, Ltd., E. K...... 26 Six-Sixty Radio Co., Ltd. 20 Sovereign Products ... 64 ! Cossor, Ltd., A. C. 16 Dyson & Co. (Works), Ltd., J. 78 Telsen Electric Co., Ltd. 10 Edison Bell, Ltd...... 41 Falk Stadelmann & Co., Ltd. 87 Headphones. Ferranti, Ltd.... 45 Brown, Ltd., S. G. 2 Fullotone Gramophones, Ltd. 201 Kolster-Brandes, Ltd. 25 General Electric Co., Ltd. ... 24 & 77 Lissen, Ltd. 17 Heayberd & Co., F. C. 68 Igranic Electric Co., Ltd. 28 Instruments and Meters. Junit Manufacturing Co., Ltd. 97 Automatic Coil Winder & Electrical Kolster-Brandes, Ltd. 25 Equipment Co., Ltd. ... 207 Lissen Ltd. 17 Park Royal Engineering Co., Ltd. ... 194 Mains Power Radio Co. 229 Standard Battery Co. 94 Marconiplione Co., Ltd. 4 Labels. Radio Instruments, Ltd. 29 Gripso Co. 81 Regentone, Ltd...... 22 Six-Sixty Radio Co., Ltd. 20 Loud Speakers. Tannoy Products 63 B. & S. Electrical Co., Ltd. ... 181 Turner & Co. ... 82 Bakers Solhurst Radio 216 British Blue Spot Co., Ltd. ... 65 Faders. British Radiophone, Ltd. 155 British Rola Co., Ltd. 250 Auto Electric Devices, Ltd. ... 159 Brown, Ltd., S. G. 2 Brownie Wireless Co. of G. B., Ltd. 37 Filters. Bullplione, Ltd. 12 Edison Bell, Ltd...... 41 Burton, C. F. & H. ... 31 Lamplugh, Ltd., S. A. 168 Calders, Ltd...... 183 Sovereign Products, Ltd. 64 Colestion, Ltd...... 40 Cole, Ltd., E. Iv...... 26 Fuses and Fuse Holders. Columbia Graphophono Co., Ltd. 7 Colassion, Ltd. 209 Belling & Lee, Ltd. ... 13 Cossor, Ltd., A. C. 16 Bulgin & Co., Ltd., A. F. 102 Donotone (Rogd.) Loud Speaker 161 Hunt, Ltd., A. H. 232 Edison Bell, Ltd. 41 Edison Swan Electric Co., Ltd. 21 Gramophone Motors. Epoch Radio Mfg. Co., Ltd— 106 Auto Electric Devices, Ltd. 159 Ericsson Telephones, Ltd. ... 219 Betta Electric Motel’s, Ltd. ... 218 Falk, Stadelmann & Co., Ltd. 87 Edison Swan Electric Co., Ltd. 21 Ferranti, Ltd.... 45 Electric Gramophones, Ltd. 89 Fullotone Gramophones, Ltd. 201 Garrard Engg. & Mfg. Co., Ltd. 178 General Electric Co., Ltd. ... & 77 Igranic Electric Co., Ltd. 28 Goodmans 239 Rolls-Cay don, Ltd...... 56 Graham Amplion, Ltd. 75 Simpsons Electricals Ltd. ... 93 Graham-Farish, Ltd.... 32 Standard Battery Co. 94 Johnson Talking Machine Co., Ltd. 180 Kolster-Brandes, Ltd. 25 Lamplugh, Ltd., S. A. ... 168 Gramophone Pick-ups and Arms. Lissen, Ltd. 17 Auto Electric Devices, Ltd...... 159 Marconiplione Co., Ltd. 4 B. & S. Electrical Co., Ltd...... 181 Magnavox (G. B.), Ltd. 108 British Radiophone, Ltd...... 155 Mains Radio Gramophones, Ltd. 53 Brown, Ltd., S. G...... 2 Mullard Radio Valve Co., Ltd. 18 Celestion, Ltd...... 40 Ormond Engg. Co., Ltd. 34 Cossor, Ltd., A. C...... 16 Partridgo & Moo, Ltd. 177 Edison Bell, Ltd...... 41 Pegasus, Ltd...... 238 Edison Swan Electric Co., Ltd. 21 P. R. Products ...... 187 Electric Gramophones, Ltd...... 89 Radio Gramophone Development 11 Graham-Farish, Ltd...... 32 Rees Mace Mfg. Co., Ltd. 215 Harlie Brothers (Edmonton), Ltd. . 84 Rolls Radio, Ltd...... 256 Igranic Electric Co., Ltd...... 28 Shapland & Potter, Ltd. 217 Lissen, Ltd...... 17 Standard Battery Co. 94 Marconiphone Co., Ltd...... 4 Sovereign Products, Ltd. 64 Oliver Pell Control, Ltd. (Varley) . 58 Taylor, Ltd., Henry E...... 212 Radio Gramophone Development Co 11 Thompson, Diamond & Butcher ... 210 Rooko Bros., Ltd...... 79 Turner & Co...... 82 Six-Sixty Radio Co., Ltd...... 20 Ultra Electric, Ltd...... 10 Standard Battery Co. 94 Whiteley Eleotrical Radio Co., Ltd.... 46 Watmel Wireless Co., Ltd...... 100 Yagerphone, Ltd. ... 222 205 (Continued on next paye.) Classified Directory of Exhibits (continued). STAND NO. STAND NO. Loud Speaker Units and Chassis. Plugs and Sockets. Belling & Lee, Ltd. ... 13 British Blue Spot Co., Ltd. ... 65 102 British Radiophone, Ltd. 155 Bulgin & Co., Ltd., A. F. Burton, C. F. & H. ... 31 British Rola Co., Ltd. 250 70 Brown, Ltd., S. G. 2 Danipad Rubber Co., Ltd. Eastick & Sons, J. J. 252 Burton, C. F. & H...... 31 41 Calders, Ltd. ... 183 Edison Bell, Ltd. Graham & Co., R. F. ... 189 Celestion, Ltd. 40 81 Colassion, Ltd...... 209 Gripso Co. Hunt, Ltd., A. H. 232 Edison Swan Electric Co., Ltd. 21 202 General Electric Co., Ltd. 24 & 77 Lectro Linx, Ltd. Lissen, Ltd. 17 Goodmans 239 64 Graham Amplion, Ltd. 75 Sovereign Products, Ltd. Graham-Farish, Ltd.... 32 Lamplugh, Ltd., S. A. 168 Pole Finders. Lissen, Ltd...... 17 R. C. Radio Electric, Ltd...... 237 Marconiphono Co., Ltd. 4 Mains Radio Gramophones, Ltd. 53 Ormond Engg. Co., Ltd. 34 Public Address Equipment. P. R. Products 187 Arding & Hobbs, Ltd. 171 Primus Mfg. Co., Ltd. 193 Brown, Ltd., S. G. 2 Rooke Bros., Ltd. 79 Calders, Ltd...... 1S3 Six-Sixty Radio Co., Ltd. ... 20 Donotone Loud Speaker 161 Standard Battery Co. 94 Edison Bell, Ltd. 41 Telsen Electric Co., Ltd. 19 Igranic Electric Co., Ltd. 2S Turner & Co. ... 82 Partridge & Mee, Ltd. 177 Ultra Electric, Ltd. ... 10 Pritchard & Simpson, Ltd. 243 Smurthwaite, F. W. ... 107 Magnetic Alloys. Gutta Percha Co. ... 196 Radio Journals. “ Amateur Wireless ”... 71 154 Magnets. “ Broadcaster ” “ Listener ” 211 Bakers Selliurst Radio ... 216 “ Modern Wireless ” 67 Darwins, Ltd.... 101 “ Popular Wireless ”... 67 Swift, Levick & Sons, Ltd. ... 52 “ Radio for the Million ” SO & 199 “Radio Times” ... 211 Metal Rectifiers. “ Radio Trade Review ” ... 247 “ Wireless & Gramophone Trader ” 55 Mains Power Radio Co. ... 229 “ Wireless & Gramophone Export Westinghouse Brake & Saxby Signal Trader” 55 Co., Ltd...... 44 “ Wireless Constructor ” 67 “ Wireless Engineer & Experimental Microphones. Wireless” ... 57 Edison Bell, Ltd...... 41 “ Wireless Magazine ” 71 Harlie Brothers (Edmonton), Ltd. 84 “ Wireless Trader Year Book ” 55 Igranic Electric Co., Ltd. 28 “ Wireless World ” ...... 57 “ World Radio ” ... 211 Morse Apparatus. Radio-Gramophones. Gamage,Ltd., A. W...... 195 B. & S. Electrical Co., Ltd. 181 Brooks, Ltd., Kenneth ...... 225 Mouldings. Catesbys, Ltd...... 245 Belling & Lee, Ltd...... 13 Cole, Ltd., E. K...... 26 British General Mfg. Co., Ltd. 30 Columbia Graphophone Co., Ltd. .. 7 Brownie Wireless Co. of G. B., Ltd. 37 Danipad Rubber Co., Ltd...... 70 Birkbys, Ltd. 206 Dibben & Sons, Ltd., Wm. ... 1 C. A. V. Batteries, Ltd. 91 Edison Bell, Ltd. 41 De la Rue & Co. Ltd., Thos. 164 Edison Swan Electric Co., Ltd. 21 Edison Bell, Ltd...... 41 Electrical & Radio Products (1931) Lissen, Ltd...... 17 Ltd...... 3 Ormond Engineering Co., Ltd. 34 Ferranti, Ltd...... 45 Redferns Rubber Works, Ltd. 163 Fullotone Gramophones (1929), Ltd. 201 General Electric Co., Ltd. ... 24 & 77 Hacker & Sons, H...... 95 Panels. Halcyon Wireless Co., Ltd. ... 96 Birkbys, Ltd...... 206 Home Electric, Ltd...... 214 Colvcm, Ltd...... 38 Hustler, Simpson & Webb, Ltd. 86 Danipad Rubber Co., Ltd. 70 Itonia Gramophones, Ltd. ... 167 Peto Scott Co., Ltd...... 179 Johnson Talking Machine Co., Ltd. 180 Redfem’s Rubber Works, Ltd 163 Kolster-Brandes, Ltd. 25 Wright & Weaire, Ltd. 152 Lissen, Ltd...... 17 200 (Continued, on next pay a.) Classified Directory of Exhibits (continued). STAND NO. STAND NO. Radio Gramophones {continued). Radio Receivers, Battery Operated. B. & S. Electrical Co., Ltd...... 181 McMichael, Ltd., L. ... 5 Brown, Ltd., S. G. 2 Marconiphone Co., Ltd. 4 Brownie Wireless Co. of G. B., Ltd.... 37 Mains Radio Gramophones, Ltd. ... 53 Burton, C. F. & H...... 31 Oliver Pell Control, Ltd. (Varley) ... 58 Columbia Graphophone Co., Ltd. ... 7 Radio Gramophone Development Co. 11 Cossor, Ltd., A. C. 1G Rolls Caydon, Ltd...... 56 Craufurd Wireless 242 Rolls Radio, Ltd. 25G Danipad Rubber Co., Ltd. ... 70 Rooke Bros., Ltd. 79 Dibben & Sons, Ltd., Wm. ... l Selectors (1931), Ltd.... 83 Edison Bell, Ltd. 41 Smurthwaite, F. W. ... 107 Edison Swan Electric Co., Ltd. 21 Tannoy Products 63 Electrical & Radio Products (1931), Thompson, Diamond & Butcher ... 210 Ltd...... 3 Yagerphone, Ltd...... 222 Falk, Stadelmann & Co., Ltd. 87 Fauclols, Ltd...... 192 Fullotone Gramophones, Ltd. 201 Radio Receivers, Mains Operated. Gamage, Ltd., A. W. ... 195 B. & S. Electrical Co., Ltd. . 1S1 General Electric Co., Ltd. 24 & 77 British Blue Spot Co., Ltd. 65 Graham Amplion, Ltd. 75 Brooks, Ltd., Kenneth . 225 Hustler, Simpson & Webb, Ltd. 86 Brown, Ltd., S. G...... 2 Johnson Talking Machine Co., Ltd.... 180 Brownie Wireless Co. of G. B., Lt< 37 Kolster-Brandcs, Ltd. 25 Lisson, Ltd. 17 Catesbys, Ltd...... 245 Lotus Radio, Ltd. 23 Climax Radio Electric, Ltd. 42 McMichael, Ltd., L. ... 5 Cole, Ltd., E. K...... 26 Marconiphone Co., Ltd. 4 Columbia Graphophone Co., Ltd. ... 7 Ormond Engg. Co., Ltd. 34 Cossor, Ltd., A. C...... 16 Partridge & Mee, Ltd. 177 Danipad Rubber Co., Ltd. ... 70 Pegasus, Ltd. ... 238 Dibben & Sons, Ltd., Wm. ... 1 P. R. Products 187 Edison Beil, Ltd. 41 Pritchard & Simpson , Ltd. 243 Edison Swan Electric Co., Ltd. 21 Rolls Caydon, Ltd. ... 56 Electrical & Radio Products (1931), Selectors (1931), Ltd.... 83 Ltd...... 3 Swain, Ltd., Chas. 244 Faudels, Ltd...... 192 Taylor, Ltd., Henry E. 212 Ferranti, Ltd...... 45 Voltron Electric, Ltd. ... 227 Fullotone Gramophones, Ltd. ... 201 Yagerpkoue, Ltd. ... 222 Gamage, Ltd., A. W. ... 195 General Electric Co., Ltd. . 24 & 77 Radio Receivers, Portable. Graham Amplion, Ltd. 75 B. & S. Electrical Co., Ltd...... 181 Greatrex & Co., R. G. 197 Brown, Ltd., S. G. 2 Halcyon Wireless Co., Ltd. .. 96 Columbia Graphophone Co., Ltd. ... 7 Home Electric, Ltd. ... 214 Cossor, Ltd., A. C...... 16 Johnson Talking Machine Co., Ltd ISO Danipad Rubber Co., Ltd. ... 70 Junit Mfg. Co., Ltd. ... 97 Edison Bell, Ltd. 41 Kolster-Brandes, Ltd. 25 Electrical Devices Co. 185 Lamplugh, Ltd., S. A. 168 Electrical & Radio Products (1931), Lissen, Ltd...... 17 Ltd...... 3 Lotus Radio, Ltd...... 23 Falk, Stadelmann & Co., Ltd. 87 McMichael, Ltd., L...... 5 Faudels, Ltd. ... 192 Marconiphone, Co. Ltd. 4 General Electric Co., Ltd. 4 & 77 Mains Radio Gramophones, Ltd. ... 53 Graham Amplion, Ltd. 75 Murphy Radio, Ltd. ... 59 Homo Electric, Ltd. ... 214 Oliver Pell Control, Ltd. (Varley) ... 58 Junit Mfg. Co., Ltd. ... 97 Ormond Engineering Co., Ltd. 34 Kolstor-Brandes, Ltd. 25 Partridge & Mee, Ltd. 177 Lissen, Ltd...... 17 Pegasus, Ltd...... 238 McMichael, Ltd., L. ... 5 Pritchard & Simpson, Ltd. 243 Marconiphono Co., Ltd. 4 Pye Radio, Ltd. 9 Montague Radio Inventions & Dev Radio Gramophone Development Co. 11 Co., Ltd. 47 Radio Instruments, Ltd. 29 Murphy Radio, Ltd. ... 59 Rees Mace Mfg. Co., Ltd. 215 Overseas Trading Corporation 173 Regen tone, Ltd. 22 Pegasus, Ltd...... 238 Rooke Bros, Ltd. 79 Portadyne Radio ... 103 Rolls Caydon, Ltd. ... 56 Pyo Radio, Ltd. 9 Selectors (1931), Ltd.... 83 Rees Mace Mfg. Co., Ltd. 215 Smurthwaite, F. W. ... 107 Rolls Caydon, Ltd...... 56 Tannoy Products 63 Rolls Radio, Ltd. ... • 256 Taylor, Ltd., Henry E. 212 Selectors (1931), Ltd...... S3 Ultra Electric, Ltd. ... 10 Slolctun Products 208 Umello, Ltd...... 73 Swain, Ltd., Chas...... 244 Voltron Electric, Ltd. 227 Sovereign Products, Ltd. 64 Yagerphone, Ltd. 222 Wliittingham, Smith & Co...... 103 207 {Continued on next page.) Classified Directory of Exhibits (continued). stand NO. Stand no. Radio Receivers, Stenode Radiostat. Resistances {continued). Radio Instruments, Ltd. 29 Igranic Electric Co., Ltd. » » . 28 Smurthwaite, E. W...... 107 Lissen, Ltd...... 17 London Electric Wire Co. & Smiths, Radio Receivers, Superheterodyne. Ltd...... 27 B. & S. Electrical Co., Ltd...... 1 SI 229 41 Mains Power Radio Co. Edison Bell, Ltd. Oliver Pell Control, Ltd. (Varley) ... 58 Electrical Devices Co. ... 185 34 24 & 77 Ormond Engg. Co., Ltd. General Electric Co., Ltd. Paroussi, E...... 158 Halcyon Wireless Co., Ltd. ... 96 177 214 Partridge & Mee, Ltd. Home Electric, Ltd...... Regentone, Ltd. 22 Kolster-Brandes, Ltd. 25 79 5 Rorke Bros., Ltd. McMichael, Ltd., L. ... Six-Sixty Radio Co., Ltd. 20 Marconiphone Co., Ltd. 4 Standard Battery Co. 94 173 Overseas Trading Corpoi'ation Sovereign Products, Ltd. 64 Radio Gramophone Devel. Co., Ltd 11 19 215 Telsen Electric Co., Ltd. Rees Mace Mfg. Co., Ltd. Turner & Co. ... 82. Rolls Caydon, Ltd. ... 56 Watmel Wireless Co., Ltd. ... 100 83 Selectors (1931), Ltd...... Wright & Weaire, Ltd...... 152 Radio Receivers, Short Wave. Eddystone Radio 98 Retail Distributors, General Display. 24 Arding & Hobbs, Ltd. 171 General Electric Co., Ltd. 245 McMichael, Ltd., L. ... 5 Catesbys, Ltd. Gamagc, Ltd., A. W. 195 Radio Gramophone Development Co. 11 234 Stratton & Co., Ltd. ... 98 Selfridge & Co., Ltd. ... Whiteley, Ltd., William 198 Radio Receivers, Crystal. Scanning Discs. Brownie Wireless Co. of G. B., Ltd.... 37 Baird Television, Ltd. 157 Radio Receiver Kits. Paroussi, E. ... 158 Bullphone, Ltd. 12 Screens. Burton, C. F. & H. ... 31 Colvern, Ltd...... 38 Cossor, Ltd., A. C. 16 Paroussi, E. 158 General Electric Co., Ltd. ... 24 & 77 Peto, Scott Co., Ltd...... 179 Mullard Radio Valve Co., Ltd. 18 Six-Sixty Radio Co., Ltd. 20 Poto, Scott Co., Ltd...... 179 Watmel Wireless Co., Ltd...... 100 P. R. Products ...... 187 Whiteley Electrical Radio Co., Ltd.... 46 Ready Radio, Ltd...... 6 Wright & Weaire, Ltd. 152 Six-Sixty Radio Co., Ltd. ... 20 Sleeving. Telsen Electric Co., Ltd. 213 248 Voltron Electric, Ltd. 227 Concordia Electric Wire Co., Ltd. ... Yagerphone, Ltd...... 222 London Electric Wire Co. & Smiths, Ltd...... 27 Receiver Kits, Short Wave. Stampings and Pressings. Eddystone Radio 98 232 Stratton & Co., Ltd. ... 98 Hunt, Ltd., A. H. Ormond Engg. Co., Ltd. 34 Recorders. Cole, Ltd., E. K...... 26 Station Indicators. “ Fay ” Home Recorders, Ltd. 220 Smurthwaite, F. W...... 107 Overseas Trading Corporation 173 Superheterodyne Components. Speakeasie Home Recorders, Ltd.... 236 Wright & Weaire, Ltd. 152 Rejectors. Switches. British Blue Spot Co., Ltd...... 65 Benjamin Electric, Ltd. 99 Brownie Wireless Co. of G. B., Ltd.... 37 Bulgin & Co., Ltd., A. F. 102 Dubilier Condenser Co. (1925), Ltd.... 92 Burton, C. F. & H...... 31 Kolster-Brandes, Ltd. 25 Colvern, Ltd...... 38 Sovereign Products, Ltd. 64 Danipad Rubber Co., Ltd. ... 70 Watmel Wireless Co., Ltd. ... 100 Graham-Farish, Ltd.... 32 Gripso Co...... 81 Remote Controls. 156 Bulgin & Co., Ltd., A. F. 102 Jewel Pen Co., Ltd...... Junit Mfg. Co., Ltd...... 97 Resistances, Fixed and Variable (including Lissen, Ltd. 17 Volume Controls). Lotus Radio, Ltd...... 23 Auto Electric Devices, Ltd. ... 159 Ormond Engg. Co., Ltd. 34 Belling & Lee, Ltd. ... 13 Pioneer Mfg. Co., Ltd. 188 Bulgin & Co., Ltd., A. F. 102 Rooke Bros., Ltd...... 79 Burton, C. F. & H...... 31 Six-Sixty Radio Co., Ltd. ... 20 Clarke & Co. (M/c.), Ltd., H. 33 Sovereign Products, Ltd. 64 Colvern, Ltd...... 38 Taylor, Ltd., Henry E. 212 Concordia Electric Wire Co., Ltd. 248 Telsen Electric Co., Ltd. 19 Cossor, Ltd., A. C. 16 Valunda Switches ... 224 Dubilier Condenser Co. (1925), Ltd.... 92 Whiteley Electrical Radio Co., Ltd. 46 Edison Bell, Ltd. 41 Wilkins & Wright, Ltd. 90 Graham-Farish, Ltd.... 32 Wright & Weaire, Ltd. 162 208 (Continued on next page.) Classified Directory of Exhibits (continued). STAND NO. SfAtfD rio. Synchrophones (Radio, Gramophone and Turned and Pressed Parts. Cinema combined). Synchrophone, Ltd...... 223 British Radiophone, Ltd. ... 155 Colvern, Ltd. ... 38 Televisors. Jewel Pen Co., Ltd...... 156 Baird Television, Ltd. 157 Turntables. Television Kits. Baird Television, Ltd. ... 157 Benjamin Electric, Ltd. 99 British Radiophone, Ltd. 155 Terminals, Screws, Connectors, etc. Lissen, Ltd. 17 Belling & Lee, Ltd. ... 13 Six-Sixty Radio Co., Ltd. 20 Bulgin & Co., Ltd., A. F. 102 Burton, C. F. & H. ... 31 ! Valves. Eastick & Sons, J. J. ... 252 Cossor, Ltd., A. C...... 16 Hunt, Ltd., A. H...... 232 Edison Swan Electric Co., Ltd. 21 Lectro-Linx, Ltd...... 202 General Electric Co., Ltd. 4 & 77 Lissen, Ltd. 17 Testing Instruments. 4 Eastick & Sons, J. J. ... 252 Marconiphone Co., Ltd. Milliard Radio Valve Co., Ltd. 18 & 221 Siemens El. Lamps & Supplies, Ltd. 74 187 Six-Sixty Radio Co., Ltd. 20 P. R. Products Six-Sixty Radio Co., Ltd. 20 Tone Controls. Edison Bell, Ltd...... 41 Valve Holders. Harlie Bros. (Edmonton), Ltd. 84 Benjamin Electric, Ltd. 99 Bulgin & Co., Ltd., A. F. 102 Tools. Burton, C. F. & H...... 31 Atalanta ... 191 Danipad Rubber Co., Ltd. ... 70 Dyson & Co. (Works), Ltd., J. 78 Transformers. Graliam-Farish, Ltd.... 32 British General Mfg. Co., Ltd. 30 Junit Mfg. Co., Ltd. ... 97 British Radiophone, Ltd. 155 Lcctro Linx, Ltd. 202 Brownie Wireless Co of G. B., Ltd. 37 Lissen, Ltd. 17 Burton, C. F. & H...... 31 Lotus Radio, Ltd. 23 Clarke & Co. (M/c), Ltd., H. 33 Paroussi, E...... 15S Climax Radio Electric, Ltd. ... 42 Tolson Electric Co., Ltd. 19 Cossor, Ltd., A. C. 16 Tonex Co. 231 Danipad Rubber Co., Ltd. ... 70 Whiteley Electrical Radio Co., Ltd 46 Dyson & Co. (Works), Ltd., J. 7S Wright & Weaire, Ltd. 152 Ferranti, Ltd.... 45 Graham-Farish, Ltd.... 32 Volume Controls. Igranic Electric Co., Ltd. 28 Junit Mfg. Co., Ltd. ... 97 {See Resistances) Lissen, Ltd. 17 London Electric Wire Co. & Smitl Wholesale Distributors, General Display. Ltd...... 27 Boaver Electrical Supply Co. 165 Lotus Radio, Ltd. ... 23 Brown Brothers, Ltd. 105 Mains Power Radio Co. 229 Cadisch & Sons, R...... 184 Olivor Poll Control, Ltd. (Varloy) 58 Churchmans, Ltd...... 200 Ormond Engineering Co., Ltd. 34 Dayzito, Ltd...... 251 Partridge & Mee, Ltd. 177 Dow & Co., Ltd., A. J. 104 P. R. Products 187 Dulcetto-Polyphon, Ltd. 230 Radio Instruments, Ltd. 29 East London Rubbor Co., Ltd. 176 Ready Radio, Ltd. 6 Faudels, Ltd. ... 192 Regentone, Ltd. ... 22 Flindors (Wholesale), Ltd. ... 204 Rolls Radio, Ltd...... 256 Hillman Brothers, Ltd. 166 Rooke Bros., Ltd. Hobday Brotliors, Ltd. 17579 Slektun Products ...... 208 Houghtons the Wholesalers .. . 85 Sovereign Products, Ltd. Itonia Gramophones, Ltd...... 16764 Telsen Electric Co., Ltd. 19 Johnson Talking Machine Co., Ltd.... 180 Tonox Co...... 231 Kalisky (Aldgato), Ltd., S...... 151 Turner & Co...... 82 L. E. S. Distributors, Ltd. ... 88 Whiteley Electrical Radio Co., Ltd. 46 ■ Manufacturers Accessories Co. (1928), Wright & Weaire, Ltd. 152 Ltd...... 186 Mellor, G...... 255 Transmitting Apparatus. Priestly & Ford ...... 69 Eddystone Radio 98 Sol-Ezi Wiroless Supply Co., Ltd. ... 190 Stratton & Co., Ltd...... 9S Sun Electrical Co., Ltd...... 203 ! Thompson Diamond & Butcher ... 210 Trickle Chargers. ' Cole, Ltd., E. K. 26 Dyson & Co. (Works), Ltd., J. 78 | Wires and Cables. Mains Power Radio Co. ... 229 Concordia Electric Wire Co., Ltd. ... 24S London Eloctric Wire Co. & Smiths, Tuning Units. Ltd...... 27 {Sea Coils) Now London Electron Works, Ltd. 35 209 : ; i . J : \ 210 INDEX TO ADVERTISERS. PAGE PAGE Abbott, John G...... 122 • Lectro-Linx. Ltd. .••• ... 140 I Automatic Coil Winder & Electrical Lile, Ltd., John H. ... 130 Equipment Co., Ltd. ... 5S, 106 Lissen, Ltd. ... 64 Lithanode Co., Ltd. ... 144 B. S. Electrical Co. ... 22 London Electric Wire Co. & Smith’s, Ltd. S2 Belt a Electric Motors, Ltd. • ... 1S6 Lotus Radio, Ltd. 18 Bird &, Sons, Ltd., Syclncy S...... 168 British Blue Spot Co., Ltd...... 12S McMichael, Ltd., L. ... 44 British Broadcasting Corporation .., 4S Marconiphone Co., Ltd...... 42 Broadcaster & Wireless Retailer ” ... 162 Mather & Cro'wtlier, Ltd. ... 80 Brooks & White ...... 90 Metropolitan Railway ... 35 Brown Brothers, Ltd...... 156 Mullard Wireless Service Co.. Ltd. ... 66 Brownie Wireless Co. of G. B., Ltd. ... 100 Burton, C. F. & H...... ’... 88 National Accumulator Co., Ltd. 1 New London Electron Works, Ltd. C.A.Y. Batteries, Ltd. 14 Inside Hack Cover Carrington Mfg. Co., Ltd. ... 122 Olympia, Ltd. ... 50 ' Celestion, Ltd. ... 104 : Chloride Electrical Storage Co., Ltd. Ormond Engineering Co., Ltd...... 94 •Spine, 32, 33 Osborn, Chas. A. ... 180 Cole, Ltd., E. K...... 4 Clarke & Co. (M/c), Ltd., H...... 92 Perton, A...... 86 I Columbia Graphophone Co., Ltd. 36, 37 I ' Pertrix, Ltd. ... 102 Concordia Electric Wire Co., Ltd. ... 134 Peto Scott Co., Ltd...... 172 Cook’s Furnishing Stores ... 212 Priestley & Ford ...... 110 Cossor, Ltd., A. C...... • 62 Primus Mfg. Co., Ltd. ... 192 Craufurd Wireless ... 134 Pye Radio, Ltd...... *. 20 “ Daily Express ”...... 52 Radio Society of Great Britain ...... 184 * < Daily Herald ” ... 78 Radio Gramophone Development Co., ... 56 “ Daily Mail ” ...... 6 Ltd...... 184 “ Daily Mirror ”...... 38 Redfern’s Rubber Works, Ltd. ... Dnnipad Rubber Co., Ltd. ... 99 Regentone, Ltd...... 74 ... 154 Darwins, Ltd. Sankey & Sons, Ltd., Joseph ... 114 ... 108 Dayzite, Ltd. Scott Insulated Wire Co., Ltd. ... 59 Dubilier Condenser Co. (1925), Ltd. ... 150 Selectors (1931), Ltd...... 144 ... 98 Dyson & Co. (Works), Ltd., J. ... Slektun Products, Ltd...... 132 Edison Bell, Ltd...... Inside Front Cover Smurthwaite, F. W. 158, 170 Electrical & Radio Products (1931), Ltd. 96 Straker Brothers, Ltd...... 84 .Ericsson Telephones Ltd. ... 210 Stroud Bros., Ltd. ... 198 “ Evening Standard ” ... 40 Strutt, F...... 70 Ever Ready Co. (G. B.), Ltd. ... 2 Sun Electrical Co., Ltd. ... 12 “ Sunday Referee ” ...... 72 Faudels, Ltd...... 98 Swift Lcvick & Sons, Ltd. ;.. 116 “ Fay ” Home Recorders, Ltd...... 118 Ferranti, Ltd. 60, 112 Telsen Electric Co., Ltd. ... 68 Formo Co— ... 124 Thompson Diamond & Butcher...... 182 " The Times ” ... 46 Gamnge, Ltd., A. W. ... 136 Turner & Co. ... 142 Gee & Co. 7 General Electric Co., Ltd. ... Back Cover Ultra Electric, Ltd...... 54 General Window Cleaning Co...... 140 Valunda Switches ... 136 Graham Amplion, Ltd...... 13S Varley (Oliver Pell Control, Ltd.) ... 120 Gripso Co. ... . 98 Gutta Percha Co...... 142 Whiteley Electrical Radio Co., Ltd. ... 159 Wilkins & Wright, Ltd. ... Heayberd & Co., F. C...... 192 ... 14S “ Wireless & Gramophone Trader ” ... 34 Hustler, Simpson & Webb, Ltd. ... 146 “Wireless World” ... 16 Ilift'e & Sons, Ltd. ... 16 Wright & Weaire, Ltd...... 170 I Jackson Bros. ... 126 I Yagerphone, Ltd. ... 170 i 211 Telephone Originally Established SHEPHERDS BUSH 2331. 2 8c 3. 1 888. C.F.S. C.F.S. Charles Cooks FURNISHING STORES. CHARLES A. COOK, PROPRIETOR 7, 9, 11 & 13 MACLISE ROAD, WEST KENSINGTON, W.14. & AT COOK'S CORNER, NORTH END ROAD, WALHAM GREEN. Exhibition Hire Furnishers Complete House Furnishers. Furniture Supplied on Hire for Fetes, Whist Drives, Concerts, Balls, ETC. appointed official furnishers to most OF THE PRINCIPAL LONDON EXHIBITIONS. Our Premises adjoin the Olympia. INSPECTION INVITED. 212 STRAKER BROTHERS LTD.. PRINTERS, LONDON* E.C.2 BlBUOTHEfc* ' 1 ; N.V.H.R, ' SOMETHING NEW! ELECTRON k SCREEN AERIAL Master Patent No. 260089. GOME and SEE US AT STAND No. 35 NATIONAL HALL Lead-In to suit requirements—illustration shows 22 ft. Electron, price 6d. extra. Scientifically designed to give greater Selectivity and volume. Does away with masts as the Screen Aerial can be fitted on the side of the house or chimney., in the loft, under the roof or behind the cupboard door. This new radio sensation costs only 15s.—from your dealer or direct, 15'(POSTAGE 9d.l attractively boxed. FOR YOUR LEAD-IN ALWAYS USE SUPERIAL 100 ft. 2/6 soft. 1/6 ELECTRON 50 ft. 1/- 25 ft. 6D ELECTRON INSULATOR PINS. OAK MAHOGANY With Electron Insulator Pins a directional aerial BLACK or WHITE can be instantly removed and fixed at different (o match your decoration!. angles at either end or across the*room; simply pull out the pins and fix in varying positions until the best results are obtained. . Fixed in a POST 0D'per moment they grip and insulate your lead-in neatly FREE VP BOX and invisibly. OF SIX Now available in different Colours. Uhe NEW LONDON ELECTRON WORKS Ltd. Telephone : Grangewood I-108-9—1363 EAST HAM LONDON.E.6 -jJSTZj.- 4 I . !l ■ •- w- I Hi \ You can’t H \ f \ I y go wrong wi th f &£C. Radio i For particulars oj G*E.C. Stands, see pp. 77, 141, and 195. m mmmggf* --«^a Supremacy in Radio nliotheek Ned. £6*.C Radio MADE IN ENGLAND o/ The-General'Electric\Co , Ltd., Magnet House, Kingsway, London, W.C 2.