Am Teur Radio

In This Issue - World -Wide Radio Digest

Best S -W Station List

Directory 5 -W Hams Building A Television Receiver Radio Test Quiz

S -W Listening Tips Receiver Construction

SEE PAGE 454

25 IN U S AND CANADA HUGO RADIO EXPERIMENTING DEC. GERNSBACK EDITOR asas AM www.americanradiohistory.comTEUR RADIO You can't lose! A money -back guarantee protects you!

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www.americanradiohistory.com RADIO a.TELEVISION DECEMBER -1938 Vol. IX No. 8 7 / F^ per 1t,,;tirh1e

New ! Exclusive ! HUGO GERNSBACK, Editor H. WINFIELD SECOR, Manag. Editor Roster of ROBERT EICHBERG, Assoc. Editor New HAMS

Se(: Page 493

_On "A[1 gigue

GENERA I. FEATURES CONSTRIF1 'THIN 469 Ultra Short Waves and Television - New Experiments with Radio Apparatus Dr, Greenleaf Whittier Pickard 453 Radio Kinks 477 T.R.F. 441 -Line Television Receiver -Henry Townsend 478 Can You Recognize These Sound Effects? 454 480 3 -Tube A.C. Receiver-J. T. Wilcox, W2CLS Television Eye Pierces Fog.. 455 Economical 25 Watt Xmitter Kit. 480 Radio Digest... 456 Tubes G. Haas World -Wide I -Meter Waves with Ordinary -Nelson 484 Aviation's Newest and Biggest Radio Rig -C. L. Stong 458 and Carl A. Erbacher Build This 4 -Tube HAM Beginner's Receiver- C.B.S. "Sets The Stage" for TELEVISION 460 Harry D. Hooton, W8KPX... _ .. 486 461 With The YL's 110 Volt D.C. Transmitter, Part II- Conclusion Yellin, W2AJL 502 Radio Directs Making of a Feature Movie -J. M. Goldby 464 Herman

CONDENSED FE.tTI -Ii ES TELEVISION Super -Imposing Television Images .455 Television Eye 455 .. ..456 World -Wide Radio Digest.. "Television in the Spring" - Radio Altimeter for Planes 456 Sarnoff's Promise 457 Whale Wired for Sound 456 Next //tenth C.B.S. "Sets the Stage" for New Laws for "Hams" .. 456 Television . 460 Television Airplane Beacon. .. 457 Television- Tomorrow's Big Opportun- Receiver Ireland Rushes Transmitter 457 T.R.F. Television William Dubilier. 478 ity- Television Promised in Spring 457 -How To Build 459 Two -Stage Preselector for Use with Radioddities G. International Radio Review 462 Communications Receiver -H. MISCELLANEOUS McEntee, W2FHP. "C" & "R" Meter 462 11/4 Meter Sets 462 459 Experimental Radioddities One-Tube Receiver for a Short Aerials. 463 Good New Television Radio Test Quiz 467 Wave Listener - Herman Yellin, Short Waves on the SS. "Nieuw League the Ham 466 Short Wave -"On W 2AJ L. Amsterdam" Bands" -Elmer R. Fuller...... 470 Radio Talks from a Jungle 466 An Emergency Ham Transmitter-Her- Local HAM Gossip 471 man Yellin, W2AJL. What Do YOU Think? 472 Silver Trophy Award for Best Station Ultra Snort Wave Aerials, Including INSTR I -C TION Photo 473 Television Types. 474 Radio Beginner's Course - World Short Wave Stations Zworykin's Automatic U.H.F. Relay 465 Martin Clifford, W2CDV Let's Listen In with Joe Miller.. 475 System. Radio Test Quiz- Robert Eichberg..467 Radio Kinks 477 And Al Your Favorite Departments. Shooting Trouble on the Ham Trans- Question Box 482 Abrams, W2DTT. 468 mitter -Alvin Directory of Newly Licensed Question and Answer Department 482 Amateurs .. 493 New Radio Apparatus 499

Certified Circuits Cover composition by H. Gernsback and Thomas D. Pentz. Pho- tos: Courtesy Notional Broadcasting Company (see page 454). When you see this seal on a set it is a guarantee that tested and Entered matter Feb. 15, it has been RADIO & TELEVISION -Published monthly on the tenth of the month. as second class act of March 3. 1979. Trademarks and copyrights by per- certified in our laboratories, 1938, at the post office at Springfield, Mass., under the and may not be reproduced without permission. Sub- mission of H, Gernsback. Text and illustrations are copyright as well as privately in different parts of and Canada. $3.00 in foreign countries. Make all scription price $2.30 a year in the United States and possessions subscription checks payable to popular Book Commotion. the country. Only constructional-experimental sets are certified. St., Springfield, Mass. Editorial and spend Published by Popular Seek Corporation. Publication Office -29 Worthington You need not hesitate to President: II. W. SECOR, Vice -President: Executive 0111ces -99 Hudson St.. New York. S.Y. DUt:0 GERNSBACK, the set and Distributing Co., Ltd., 18 Bride money on parts because E111. GROSSMAN. Director of Advertising. European Agents: Atlas Publishing and Agents: McGill's Agency, 179 Elizabeth fide. Lane. Fleet St., London, England; Brentano's- London and l'aris. Australian circuit are bona St., Melbourne. This is the only magazine that renders such a service. Copyright 1938 by H. Gernsback 450

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101 SHORT WAVE HOW TO GET HOOK -UPS BEST SHORT WAVE RECEPTION ?e Compiled by the Editors of 1 M. HARVEY GERNSBACK tells l i RADIO & TELEVISION you everything you have ever wanted to know about short wave reception. Itere is a worthwhile hook that every The author, a professional radio wave listener, every short wave listener and radio fan for many years, fan. and every short wave amateur gives you his long experience in radio t has wanted for a long time. It gives reception and all that goes with it. you the 101 hest short wave hook -ups SHORIWAVEI Mitch have appeared heretofore. 40 Illustrations 72 Pages SOc n0000ltU PS 100 IUust rations 72 Pages SOc

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www.americanradiohistory.com AS

HUGO GERNSBACK, EDITOR H. WINFIELD SECOR, MANAGING EDITOR Ultra Short Waves and Television Dr. Greenleaf Whittier Pickard

AS this editorial is written, the Euro- of the world's amateurs are concentrated pean situation is still uppermost in our in this country: it is because we alone, minds, and frequently -asked questions are: of the world's nations. have consistently What part will radio play in the next war, encouraged amateur radio. aside from its normal use in military com- Having already mentioned, as an advan- munication? Will radio methods be de- tage of ultra high frequency broadcasting, veloped for the location of enemy sub- the fact that such waves are strictly limited marines? How will a nation at war, or ill range, one is led to a further discussion preparing for war, best keep in touch with of this advantage. As is well- known, the its citizens? It may interest your readers lower frequency waves used in normal to discuss these and allied questions from broadcasting are nightly turned back to a broadcast engineer's viewpoint. earth at considerable distances from the During the past quarter century many transmitter. This "turned back ". or sky- tests have been made of radio communica- ware has its disadvantages in broadcasting, tion to and from submarines, and the results as a brief analysis will show. There are at of these tests have been in full agreement present three general classes of broadcast- with the simple theory of electro- magnetic ing stations in this country, namely. clear screening by a conductor. Salt water is a channel, regional and local. While the clear rather good conductor, so good in fact that channel stations snake some use of the sky - only low frequency waves can penetrate wave in serving large areas of rural popu- it to any appreciable depth, so it would lation with an inferior or secondary cover- seem that radio methods of locating sub- age, sky waves are a positive and serious merged submarines would be of little value. disadvantage to regional and local sta- In the next war, as in the World \Var, tions, by reason of the interference at night we must lean heavily on acoustical rather between such stations on the same frequency than radio methods of detecting and locat- Conyrigbl by narra dui t:e inK channel. If it were not for the sky wave, ing under -water craft. Dr. Greenleaf Whittier Pickard -one of the many more and better located regional and The problem of radio broadcasting to a foremost radio engineers in this country. Dr. local stations would be installed, and the nation in war time is essentially similar Pickard has been very active in radio research listening public would obtain a greatly to that of peace -time broadcasting, save for many years and has contributed numerous improved service. that the audience must be protected from valuable inventions to the radio art. Our read- When broadcasting is done at ultra high malicious ers will interference from enemy stations, find the views of Dr. Pickard on the frequencies there is, practically speaking, no present and, if possible, induced to ignore broad- -day aspects of ultra -short waves and sky wave and hence no co- channel inter- casts television of unusual interest. of enemy propaganda. An ideal solu- ference between stations located some two tion of this problem (as well as those of hundred miles apart, so that on a single peace -time broadcasting) has already been cipal part played by radio would again be frequency, well over a hundred stations made by Major E. H. Armstrong, and pure communication, with the dots and could be sprinkled over the United States. consists of an ultra -high frequency carrier dashes of the Morse code predominant. Of With a very limited number of frequency of frequency urodrdation. Such a system course, there would be an increasing use channels assigned to such service, say ten is immune to enemy interference from any of teletype and facsimile, and quite possibly channels, between one and two thousand considerable distance, by reason of the some use of television. And again, particu- stations could be allocated in this country. propagation characteristics of ultra high larly if this country should be involved, the And if, in addition to the use of ultra high frequencies, which are not turned back to radio amateur would play an important role, frequencies. Armstrong's system of fre- earth by the ionosphere, and hence die out as he has in many past emergencies. It takes quency modulation were used, a still larger rapidly beyond the horizon. Such a service much longer to make a technically com- number of stations could operate on these would also be relatively free from enemy petent code operator than it does to trans- same ten channels, for the reason that in- propaganda, for as soon as a nation built form a civilian into a soldier, so the nearly terference is greatly decreased by the use up a large listening audience on such a fifty thousand amateurs of the United of frequency modulation. system, few would care to stray out of the States are all important asset in time of Any consideration of ultra high frequency band into regions of enemy broadcasts at war. It is not by accident that three -quarters transmission leads inevitably to the subject lower frequencies. of television, for television, with its broad When, as, and if we have another major Twenty- second of a six- megacycle bands, is necessarily placed European Series of war, it would seen that the prin- "Guest" Editorials. (Continued on page 491)

www.americanradiohistory.com Can You Recognize (l6r.4 ...... These Sound Effects?

Airplane propeller and rush of wind past fuselage simulated by tcy propeller and air tank.

2 The crackle and roar of a fire are imitated by the sound effects man as he crumples cellophane near the mike.

3 Suicide! Sound of man's body striking pave- ment is achieved by dropping a small pump. kin onto a hard board.

4 An auto wreck or a door battered in -it's all done by crushing a berry box, to make the "breaking" sound.

5 Cloppety -clop, the cavalry comes. Two "plumber's friends' beaten together sound like horses' hammering hoofs.

6 An army marches on, when these sticks pivoted in their wooden frame are caused to tap on a table top.

7 Skeletons rattle their bones through the haunted house when the sound effects man shakes this bunch of sticks.

Anything from a zephyr to a hurricane may 8 come out of the square horn of this motor - driven wind machine. -Photos Courtesy NBC.

454 RADIO & TELEVISION

www.americanradiohistory.com INFRA -RED BEAM' POWER TRUCK

INFRA -RED ""0";,_.- SEARCHLIGHT RECTIFIER FILTER -" WITH ~LENS FILTER TO PASS INFRA -RED

R R R R

TO 110V. I A. C. 60, COAST DEFENSE IMAGE GUN SIGHT CONTROL R I _,!

IMAGE R Y 1) AMPLIFIER SWEEP/ GANGLEUN OSCILLATORS s METER BOARD

To penetrate haze or fog, television devices are used in the manner shown. The object hidden by fog or haze is illuminated by an invisible infra -red searchlight beam, and the reflected light rays are detected by an iconoscope. TELEVISION EYE Aw IMAGE OF ACTOR Pierces Superimposed Fog in ven tictni On Any Scene AS the picture above shows, it is now iconoscope tube, fitted with infra -red filter graph tube, so that both target and receiver possible to see an enemy warship or a and lens, to locate it at once. If the object, screen are scanned synchronously. ship in distress, even though hidden by fog such as an enemy warship, does not emit or haze, thanks to Herbert E. Jones who infra -red rays, then it would have to be Method for Super- Imposing Images recently was awarded a patent on this located by illumination with an infra -red John C. Batchelor recently obtained a scheme. The inventor combines the use of beam, our as artist has here shown. patent on a very ingenious scheme for an infra -red beam of light, which is in- Mr. Jones' patent shows a diagram for super -imposing two or more television visible to the ordinary eye, with the together a sweep oscillators, video amplifier, etc. images at the transmitting stations. television tube such as the iconoscope, The built sane oscillators or a.c. generators An actor could be made to appear in so as to be especially sensitive to -red which infra cause the cathode ray beam to scan a country scene, in an airplane, or walk- rays. If the object happens to emit infra- the target plate in the iconoscope tube, also ing along a street in a city ; all without red rays, it is then simple of course for the react on the cathode ray beam in the oscillo- the actor having to leave the studio. Not only is By means of this new television system, two or more scenes may be superimposed on one this idea suitable for electrically another. super -imposing one scene upon another, such as the image of an actor upon a scene SCENE (OR TELEVISION ACTOR IMAGE SCENE picked up by a 'MOVIE - PICKUP) CAMERAS second television camera IMAGE from a painted stage setting, but scenes AMPLIFIERS =ar.DS from a motion picture film may also be BLACK ,aweo, DROP picked up and super -imposed against the image of the actor. By means of a distorting amplifier, the inventor has made it possible to stagger picture impulses so that the part of a scene which will be simultaneously occupied by the image of a performer's ACTOR body, for ex- DISTORTING ample, will be obliterated-or, in other AMPLIFIER words, the resulting effect will be that the COMBINED final picture elements comprise the com- CONTROL FOR BALANC- SCENERY ACTOR / bination of the scenery and performer ING ACTOR AND SCENE sig- ANT J IMAGE nals, and the portion of the scene which ANT. r should appear immediately behind the per- \'r former (ordinarily speaking), does not ap- t! pear in the final image. The performer ordinarily appears before a black background, and in this way it is COMBIN- TELEVISION ED RECEIVER much easier for the control engineer to IMAGE blend 1 the image of the scene with that of AMPLIFIER TELE VISION TRANSMITTER the performer, as the background all around him is composed of one even tone. for December, 1938 455

www.americanradiohistory.com Measures Altitude Over Obstacles PLANE safety will be greatly increased when airlines adopt a new type of radio altimeter which is now being perfected by Western Electric engineers. The old type WORLD RADIO

Ham Helps in a Hurricane Magnetizing by Condenser WHEN the big wind struck Keene, Discharge N. H., wrecking communication systems, THE usual way to make a permanent David F. Putnam, operator of W1GVF, magnet is to wind a coil of wire around set up his transmitter in the High School a steel bar and pass current through the building. Haggard and weary, he pounded coil. As the coil must be removed later, a his key day and night for three days, small coil with high amperage is the easiest handling more than 300 messages for the solution, but means of producing large cur- Telephone Company, Red Cross and Na- rents, such as tional Guard. Sergeant Judd and Private storage batteries or dynamos, are costly. There- fore, the engi- of altimeter, now in use for aviation, meas- neers of the Bell ures the plane's height above sea level, but Telephone Lab- cannot detect such obstacles as tall buildings, oratories h i t mountain ranges, and the like. The new upon a new radio device, however, makes use of an scheme. They ultra -short wave transmitter located on one connect forty 8 wing, sending a signal groundward. The mf. condensers reflected signal, turned back by whatever in parallel. obstacle is below the plane, is picked up charge the condensers from a 350 -volt rec- by a receiving antenna on the other wing, tifier tube and discharge the condensers and is caused to actuate a needle on a through the magnet. When the impedance "Terrain Clearance Indicator" meter. of the magnet was found to produce an A.c. effect on the discharge, they simply inserted mercury vapor rectifier in series with it. France Sets Television Standards Waters, of the Guard, pitched in and helped THE French Radio Minister has an- to keep the station on the air. Other am- New Laws for Hams Begin Dec. 1 ateurs who cooperated were W1FOF, nounced that television transmission EFFECTIVE December 1, 1938, a com- ; W1AR, Boston ; W1APK, standards are now set until at least July 1, Springfield plete new set of FCC Regulations will 1 The 1941. Wavelengths will be 46 megacycles, Pembroke, N. H. and W SZ, Hartford. com- 180 meters with an govern amateur radio activities. For with the associated sound on 42 megacycles. transmitter worked on readers are advised to output of 60 watts, using 46 type tubes, and plete information, Fifty images per second will be sent, with request a copy of the regulations (which a definition of 440 to 445 lines. The picture was operated from a portable public address during the shut -off. A Na- run to 22 pages) from the Federal Com- proportion will be 5 wide to 4 high, and the system power Washington, D. C. tional 101 -X was used for receiving. -Photo munications Commission, frame synchronizing will be about 7%. Some of the more important changes These transmissions are to take place from from A. E. Freeman. are : -(1) 112 -118 and 224 -230 mc. bands the Eiffel Tower. Whale Wired for Sound now assigned to ham use. (2) Modulated oscillators and raw a.c. banned on 5 meters Large Screen Home Television MODERN ultra short-wave transmitters and up, but still permitted below 60 mc. have solved one of the most serious f _ A HOME tele- (3) Hams must provide (but need not SCREEN problems that has affected the art of whal- own) means to assure operation of trans- 24'X 19' vision receiver ing since its inception hundreds of years produc- mitter within bands ; monitors or frequency SCREEN capable of ago. One problem that the whalers had was 191( 15 ing pictures up to meters will be needed unless working the E to track down a mammoth mammal which, be N WRLC 19 x was middle of the band. (4) Power must 24 inches when wounded by the harpoon, often van- IS USED one of the fea- measured accurately if station is using over tures at a recent 900 watts. (5) Detailed rules for procedure London show. when FCC declares a communications When the lid of emergency include compulsory listening the receiver is period for first 5 minutes of each hour. 1.7 lifted, a 15 x 18 and 3.5 mc. bands reserved for relief trans- inch screen rises missions. (6) Television work permitted automatically in from 112 mc. upward, but no longer allowed the set. If this on 1.715 and 56 mc. bands. (7) No trans- SN1TCN- AUTOMATIC CHANGE OF FUCUS mission of music on ham phone ; single .WHEN USING LARGER SCREEN. _. screen is removed, another of larger tone permitted for test. Carrier to be cut stations size may be placed on the front of the re- when not modulated. (8) Only ceiver. Pressing a button changes the focus licensed to Class A operators may use the the television tube so that the image is Class A bands. (9) Portable transmitter of U.S W New data on sharp on either size screen. TRANSMITTING regulations clarified. (10) SET Class B and Class C requirements. Army Perfecting Airplane No Boxing on British Screens Detector RADIO OPERATOR MUCH secrecy surrounds the new light ON WHALING SHIP THE boxing promoters in Great Britain RECEIVES SIGNALS even beam detector which the U. S. Army is have clamped down on television, perfecting to locate enemy planes before when such a modern marvel as Jack Doyle, they get within effective bombing range of 'shed beyond the horizon. The new har- the Horizontal Harp, is in the ring. BBC American cities. The new system is not a poon has a built -in ultra short -wave trans- offered Promoter Sidney Hulls a substan- sound wave detector, as were the ones mitter, while the whaling vessel is equipped tial sum for the television rights to a Doyle formerly used, and it is understood that no with a receiver. The whale may vanish into fight. Mr. Hulls turned it down on the amount of muffling or silencing applied to the fog, but the ship can locate it instantly grounds that if a person could afford to buy the plane's motors or propellers can foil merely by listening to the signal sent out a television receiver, he could afford to the new aerial detector. by the radio harpoon. buy a ticket to the fight. 456 RADIO & TELEVISION

www.americanradiohistory.com Television Principle in Airplane Beacon AT least two American agencies are working along parallel lines to increase WIDE the safety of commercial aviation. The illus- DIGEST

Large Television a Feature of England Today -America German Show Tomorrow? PROJECTED television images. 5 x 6 TELEVISION activity in England has feet in size, were one of the outstanding necessitated the commercial production features of the German Television Exposi- of ultra short wave antennas for home in- tion. A projec- stallation, as this view of the Belling-Lee tor is used to factories proves. It has been predicted that V 4I throw the image on a wall at some distance tration shows radio research engineers of from the appar- Purdue University at work on such a sys- atus. The bril- tem. The short wave transmitter at the left liance of the pic- sends out signals which are picked up on tures was fair the cathode -ray tube receiver (shown at b u t definition the right) installed in the plane. was reported as Bell Telephone engineers are working on being inferior to a similar system, which shows airline dis- that had on patchers On the field the exact direction smaller screens. of approaching planes. The cathode -ray tube used in the Bell system will handle as many as ten planes, indicating their direction and No Hams in Greece! distance from the field on the end of a THE Greek Government has definitely cathode -rav tube marked out with compass clamped down on all importation of radio bearings. The field may then inforni each transmitting equipment and strictly forbids pilot of his exact position. the use of any transmitters by private in- dividuals. The only exceptions to these rules Television in the Spring -Sarnoff's are three amateurs who have been given Promise special licenses, says The Malayan Radio "THE Times." Indications are that they will be results of the experimental field allowed to continue activities other- tests of television in the New York area their conducted by wise only Government departments will be RCA and NBC have con- vinced us that television in the home is now permitted to own and operate radio trans- America's television boom will come early mitting equipment, which should effectively technically feasible," says David Sarnoff, in 1939 and, if so, all the factories which president of RCA. stifle Ham activities. now torn out metal tubing, auto radio an- "RCA believes that the development of tennas and similar products will show sim- its television ilar activity. system has reached a stage Argentina Active in Television where it is practicable to supply receivers satisfy TWO-HUNDREDlUNDRED line images at the Ireland Rushes Transmitter to public demand in localities where rate of 25 per second have been used television transmissions are now or may IRISH radio listeners are now trying become available. Therefore, it is planning in Argentina, but now the trend is toward to get the authorities of Radio -Eireann manufacture 405 to 441 lines. The familiar cathode -ray to and market a limited quan- to hasten construction of the new Eire short- tity of television receivers by the time the tube, which is used in American television wave station. According to "World- Radio,' New York receivers, is changed somewhat in shape World's Fair opens. We are in- a British publication, the transmitter now formed that a number of other radio manu- (become more bulbous) in South America in the course of construction at Movdrum, shape being somewhat like facturers are also preparing to manufacture -this that of near Athlone, will be operating with 3% and sell receivers. the "mushroom bulb" used for lighting in kw. power before the first of the the United States. year. Test- "We hope that advantage will be taken ing was scheduled to begin as soon as a of these opportunities to build a new in- wavelength had been assigned. dustry and establish greater public service." Fashions for Hams THE latest style hint on what the well - Nations to Dodge Enemy "Jamming" dressed Hani will wear is shown here- WHEN national stations send programs of news or propaganda to their own citizens, with -his call letters embellishing the back enemy countries frequently "jam the waves" by sending out interference on the same - -- of his workshirt. wavelength. The British Broadcasting Company has perfected plans for obviating such Newton Moyer, interference. the Beau Brum- It has long been recognized that ultra short waves do not carry efficiently beyond mel of the Short the horizon, therefore the British programs of news and other public information will Waves, got him- be sent out on these waves. Signals from transmitters on the European continent would self a silver gray have to be on similar waves in order to block the British transmissions and these waves jersey and will not travel far enough to affect reception in Britain. Educated to listen on the ultra ;W3EW bought a set of short waves, it is thought unlikely that the Britons will tune in enemy transmissions on maroon letters other wavelengths high enough to reach the "tight little isle." Simple, isn't it! from a local sporting goods ULTRA SHORT house. These 3- WAVES inch letters have rubberized backs - - and are ironed on to the shirt, after which they are sewed '))))))))?- M LES; tight. If the YL or OW can swing a wicked needle, here's a way in which she can co- F%am. in up . operate dressing the harried LONDON ' ' BERL LN

. - - Or perhaps the Hams will agree with the (ENGLAND) , - (GERMANY)?:: YL who said "Fashion is Spinach!" for December, 1938 457

www.americanradiohistory.com E. A. Post, communications engineer of United Air Lines, inspects the DC -4's direction- finding loop antenna. Two additional receiving antennas are installed beneath the ship and a transmitting antenna above her.

Aviation's Newest and A, W. E. Reichte, Bell Labs. engineer, tests the radio telephone aboard the 42 passenger DC -4. Biggest Radio Rig

c. L. Stong

DC -4, new 42- passenger plane, will have I I units of radio equipment to ensure perfect safety in the air

WHEN the giant new Douglas airliner DC-4, now undergoing tests at Santa Monica, California, roars into the sky with 42 passengers and three tons of air express, she carries the most powerful and comprehensive radio telephone yet developed for commercial air transport service. To the air -minded public this means another long stride toward ,p Stanley Beers, the goal of completely dependable air travel. Radio, and in I company radio particular two -way radio telephone between the pilot and landing technician, field, has come to occupy such an important position as a navigating carries one of instrument, as a means for communicating weather information, the receivers generally, aboard (see and as an aid to flight scheduling and flight control arrow). Some that airline officials now class it second only to the use of multiple notion of the engines as a safety device. To those charged with building our air DC -4's rela- transportation system, progress in aircraft radio as exemplified Live size is by the DC -4 equipment also means increased financial security conveyed by because it enables larger planes, carrying more passengers, to fly noting the longer distances at lower operating costs per passenger mile. stepladder The 250 watt Western Electric equipment installed aboard the under the airplane trans- huge wing. DC -4 is five times more powerful than conventional mitters and includes many unique features. For the first time. a flight crew is equipped to make simultaneous observations of the beacon, weather, and marker signals while holding two -way communication with the landing field. All power is supplied from the ship's 800 cycle auxiliary lighting plant. An intercommunicating system, that may be plugged into regular Bell System lines when the ship is on the ground, connects the pilot, co-pilot, flight engineer, and stewardess. During flight the pilot may talk over any one of ten different frequency bands, and a special direction finding loop enables him instantly to check the ship's position with respect to ground stations. All major components of the system are rack holds the intercommunicating The radio assembled to form a panel installed on the system amplifier; the 250 -watt transmitter, and recto. cunete,. receiver. Auxiliary and "bridge" immediately behind the co- pilot's Western Electric Co. the communications beacon receivers are also seen. position. This unit, operated remotely from

458 RADIO & TELEVISION

www.americanradiohistory.com a master control column which rises between the pilot and co- pilot, is entirely self - contained and is composed of the transmitter ; communication, beacon, auxiliary, and marker receivers; and the intercommunicating system amplifier. Individual control panels, mounted at both flying RADIODDITIES positions, switch either headset independently to any or all receivers without affecting As it cools WOR's monster transmit- what is heard in the other headset. Facilities ting tubes. the water in the system naturally becomes warm. When the are also included in the individual panels weather turned chilly, so many birds for switching the microphones either to the bathed in it that their feathers ship's transmitter to intercommunica- clogged up the strainers in the or the pumps. So the engineers had to ting system; for signalling the various sta- train a spaniel to keep birds away. tions connecting with the system ; for adjusting headset volume; and for placing the transmitter on the air. As the ship passes from one radio zone into the next, the transmitter and communications receiver to which it is geared are shifted progressively through five pairs of "day" and "night" frequencies, by means of a rotary dial on the transmitter panel. Instantaneous shift from day to night frequency is effected by a push -pull lever located on the master control column. Quartz -plate oscillators of new and superior design hold the several frequencies within required limits and a forced draft ventila- tion system cools the active elements of the transmitter with filtered air. The communications receiver, too, is crystal -controlled and is of the superheterodyne type. Its maximum sensitivity is adjusted from the master control column and thereafter is regulated automatically by a special vacuum tube circuit. The beacon receiver is basically similar to the communications receiver but differs in its purpose and in several minor features of mechanical design. Provision is made for reception on either a conventional single wire antenna, which is located beneath the fuselage, or from the shielded direction finding loop enclosed within the ship's No more digging fish worms. WOR's engi- wooden nose. The receiver is continuously G v.I neer Ends that a micro -wave pack trans- tunable between the frequency limits of 195 mitter drives 'em out of the ground. and 415 kilocycles by means of an illum- When CBS engineer John Norton worked an Moreover, tuning in on the worms' wave- early shift, no alarm clock could wake him, so length makes the critters turn in any inated dial on the control column which also he Invented a super -load system. A-John; size desired. Ain't Science wunnerful? contains the sensitivity control knob and an B-Bed; D, E and I- pulleys; F- String; G- indexed dial showing the loop position. Mousetrap trigger; H- Mousetrap whammer; 9 J- Switch; Kong; L -Mike; M-Amplifier; An auxiliary receiver, which may be N-Very very loud speaker. (It worked!) operated from battery supply in event of o \ I power failure, - covers all of the frequencies I/ to which the pilot would normally have ° 1 3 L occasion to listen. It is tuned remotely from tiI ',i _ the control column by flexible shafting. Mfl ---. - \ are indicated series Marker stations by a ti Op = of colored signal lights which appear in the cockpit and which may be augmented by an i°áV(- uy. audio signal heard in the headset. The crystal controlled receiver, which is of the superheterodyne type, requires no operating .atse attention during flight. c ---_ WOR engineers pe^ r-tn. transformers.._ -guM Although the importance of develop- DDlr sulphate at WñßTran.. this at the ment to the immediate needs of the industry binsmpiQér. !!! rnuráge bugs from blttlácthaevery is obvious, its real significance is to be moving in. eetle for miles 9.\1,./.X./ iëai und.vnesound, n. found in the future of aviation. "Over ehe I w according to authorities. is / derfúi eaéáywior much the weather" or sub -stratospheric flight has "Athlete's Foot.rtse Junebug. Now now all the sparrows hang around been the dominant ambition of airline oper- their !ool--Q, eck gn s. ators for more than a decade. Its realiza- e. there. tion necessitates flying above the clouds, // and out of visual contact with the ground for long distances. Hence much of the in- $5.00 for Best "Radioddity volved problem of navigation must be shift- THE accompanying pictures show a number For the best Radioddity submitted each ed from the pilot's limited senses to the of freak radio reception conditions which month, the editors offer a S5.00 prize. Others, broader reach of radio. actually occurred in the vicinity of radio whose contributions are used, will receive a transmitters. The editors will pay a $5.00 month- I year's subscription to RADIO & TELEVISION. Specifications for the new equipment were ly prize for the best "Radioddlty" sent in by In the event of a tie between two or more submitted by four leading airlines: United our readers. The description should be about contestants, an equal prize will be awarded to Air Lines Transport Corporation; Trans- 150 words in length and may be accompanied each. by a sketch or photo. The occurrences de- Closing date for the nett contest is Decem- continental and Western Air, Inc.; Ameri- scribed must be based on fact, like those here ber 10th. Prize- winning contributions will be can Airlines, Inc.; Eastern Airlines, Inc.; illustrated. published in the February, 1939, issue. and by the Douglas Aircraft Company, If you have never run across any "Radioddity" Address all contributions and communica- manufacturer of DC-4. of any nature, you may be able to act as a tions to the The system was reporter for us by interviewing radio friends Editor Radioddities designed by Bell Telephone Laboratories, and engineers, especially those connected with RADIO & TELEVISION MAGAZINE, Inc., and more than two years were re- broadcasting stations. You will probably pick 99 Hudson Street, quired to perfect and complete the initial up some very amusing Radioddities. New York, N. Y. model.

for December, 193$ 459

www.americanradiohistory.com TELEVISION HAS TECHNICALLY EN DEVELOPED TO A HIGH DEGREE. THIS ARTICLE PROVIDES THE LAT ST INFORMATION IT WILL N SOUE TOP VIEW TIME BEFORE HOME TELEVISION IS REALIZED THE ART HAS GREAT OPOEiUNInES FOR EYPE IMENTEBS AHD TECHNICIANS. OF ANTENNAS C. B. S. Sets taza S'taye bar TELEVISION AUDIO ANTENNA 'di"- 965 FT. EXPERIMENTERS equipped with television receivers will have a second source of television programs to tune in on shortly after the first of the year when the Columbia Broadcast- 16-DIPOLES ing System's new television transmitter in New York City will IN ANTENNA be completed. This station is expected to cover a radius of about SYSTEM 40 miles (an area of about 4,800 square miles). Field tests have AIR CONDITIONING indicated that under good transmission conditions, the signals APP. -75114 FLOOR from such a station may be picked up at distances greatly in excess of 40 miles, possibly 75 to 80 miles. The $500,000 transmitter is being installed in the Chrysler Building at an elevation of 874 feet. The higher the antenna, the greater the range of transmission for the ultra short waves used in television. Dr. Peter C. Goldmark, Columbia's chief television engineer, ETC. - 73RD F has charge of the installation. There will be 16 dipole antennas -8 for sound radiation and 8 for visual images. All antennas will be heated electrically by a thermostat control in cold weather so that ice cannot form on them. Powerful transformers and reactors are being installed on the upper floors of the Chrysler Tower to supply this new vision transmitter with the necessary power, totaling 1,300,000 watts. Of this great power, the COAXIAL CABLE transmitter will use about 300,000 watts for sending (TO GRAND CENTRAL out the high -definition 441 -line picture signals. `TERMINAL CONTROL The image signals will be broadcast on frequencies ROOM ,3^-t FLOOR) between 51 and 52.5 megacycles. The sound will be broadcast on 55.75 megacycles. The principal television studio is being erected in Grand Central Railroad Terminal in New York City, a short distance from the Chrysler Building. Addi- tional studios will be fitted up later. The studio control room will be connected with the television transmitter by means of a coaxial cable, of the same size as that now in use for experimental tests between New York and Philadelphia. This cable is Ç" in diameter and one spare coaxial channel is incorporated in the cable. The vision transmitter is located on PICTURE SOUND -- PANSMITTEP TRANSMITTFP the 74th floor of the Chrysler Tower, while air conditioning apparatus is located on the 75th floor. On the 73rd floor are the power transformers, reactors, motor -generators and water - cooling syste :n for the power tubes. The call letters of CBS's new television transmitter are W2XAX. Due to the very high voltages used on the tubes of the transmitter, special safety devices are provided to protect the engineers in charge. All doors to the transmitter room proper and also high Photo above shows a CBS television fitted with camera used for picking up the image voltage equipment, will be in the studio. Dr. Goldmark, CBS tele- interlock switches to cut off the power vision engineering director, is shown at automatically whenever any door or one of the monitor control panels, in photo at right, and just below it, is a panel is opened. glimpse of the television transmitter itself. Below -Television studio.

r COAXIAL CABLE LON6S 7U;5rïCs W TEL.CA

(AT GRAND CENTRAL TERMINAL) 3!D FLOOR.

LIG

460 RADIO & TELEVISION

www.americanradiohistory.com with the YLs

*DECORATIVE Elizabeth M. Zandonini (W3CDQ) got her commercial ticket in 1917, her ham license in 1922. She operates on 7, 14 and 28 mc., and works in the Natl. Bureau of Standards, in Washington. She answers letters, makes translations and helps maintain the primary standard of R.F.

*CHARMING Eve Sanford (W4DAI) is the wife of another ham, Dr. E. F. Sanford (W4DHM). She operates exclusively on cw, on the 40 meter band, and has had her license since June 29, 1934. Eve is a member of Al Opera- tors, N.W. Ga. Radio, and Rag Chewers clubs; has her WAC and WAS on 40. She can send and receive upward of 55 words a minute, though 40 is her normal rate.

*INTENT upon her rig is Ethel Clark (WBPXE), who has the works built into a folding desk, so that it can be locked away from her two small sons. Her husband, whose hobby is radio construction, built the rig. A ham for 2 years, she hopes to add another band to her program soon.

* NONCHALANT Mary E. Roden (W7GPO is an XYL like her pal, Margaret E. Will cuff (W7GQK). They're the only two of that class in their county. The two girl studied together for a year and built an 80 meter transmitter in preparation for the license exams, which they passed last January. Margaret operates on 10, 20 and 40 meters, Mary mostly on 28 mc.

4 CAPTIVATING Mae E. Amarantes (W6DHV) has been a 100% cw ham since getting her license early in 1931. She's the first YL to get a license in her section, and built her first rig with her own fair hands. Her best DX was achieved on that outfit. Mae is an active member of the ARRL, but gets most fun from rag chews. She's an XYL.

for December, 1938 461

www.americanradiohistory.com INTERNATIONAL Latest Radio Developments r.005-MF. 0.1- N MEG. 1 "C" and "R" Meter 30 enameled wire, while the grid coil is or 30 turns of the same size wire tapped 10 ' A simple meter for testing capacity turns from the end nearest the feed -back s. resistance is described in "Practical and coil. The layout is shown in Fig. 3A ; the of England. Fig. 1 Amateur Wireless" in 3B. tube socket is `, c shows the The oscillations are gen- circuit The mounted l circuit. inside the bottom of the box and the con- R erated from a D.C. source by means of a .001-MF. a fixed densers on the top. While a ground is not O' j small neon bulb paralleled with con- it denser. The transformer has a 1:1 ratio. entirely essential on this set, is apt to C) oscillate unless one is used. -Practical & The potentiometer is 10,000 ohms and is Amateur Wireless (London). C 0 provided with a pointer having two arms 'v Q to read on two separate scales-one indicat- L ing resistances; the other, capacities. The Experimental 11/4 Meter Trans- voltage source may be from 120 to 240, ob- mitter and Receiver tained either from a well -filtered lighting "Television and Short -Wave World" of line or batteries, or a well -filtered rectifier. 4 Britain shows an interesting experi- The component under test is connected mental 1% meter (240 mc.) transmitter and P011b across the X terminals, the line current receiver. Fig. 4A shows the transmitter; switched on and the potentiometer varied Fig. 4B, the receiver. These may be bread- until the hum heard through the phones dies board models and the designer, Geoffrey 0 away. Too high an input voltage will make lZ a+ 0 Parr, reported good success with this type this point hard to locate. While logarithmic of construction. In Fig. 4A, V -1 is an means of calibrating the instrument may be d` Acorn tube ; V -2 is a high -gain audio fre- used, it will be simpler to connect various quency amplifier. In Fig. 4B, V -3 is also values across the X point and draw up a an Acorn while V -4 is any standard A.F. scale from these known values filling in any amplifier tube. Condenser C -1 should be of intermediate points. the ceramic type : RI, a 5000 ohm, % watt resistor. Other values are shown in the The Super Microscope accompanying table. Television principles are employed in Cl 1000 mmf. R2 450 ohms ..n. 2 C2 10 mf. R3 500 ohms de- the latest type of microscope, as C3 10 mf. R4 100,000 ohms scribed in "Radio -Amateur," a German pub- C4 50 mmf. RS Optional -see text 100. 000 V lication. Wave lengths of light make it im- C5 100 mmf. R6 10 megohms + C6 .01 mf. R7 20,000 ohms possible to get exceedingly great magnifica- C7 10 mf. R8 500 ohms tion using optical systems. Therefore, an C8 .01 mf. R9 75.000 ohms i. electronic means whereby a stream of elec- 111 5,000 ohms trons is impeded by the object to be mag- In building the transmitter, use the Acorn nified and is then caused to spread over a socket as a starting point, positioning every- fluorescent screen, has been devised. Fig. 2A thing else as close to it as possible. The gives an analogy, the electrons being repre- same holds true for the receiver. The aerial 500 MMF. 300 MMF. sented by apples. Fig. 2B shows the prin- should be slightly under of a wave length L ciple of the microscope, but does not indicate and should be mounted on two stand -off TUBE the beam spread ; so you see where no beam (IIÌ° / insulators on the side of the chassis. If SOCKET CORNER$ size of image on the ROUNDED spread is used, the the the tuning condenser C -2 seems to have too FOR 111 would equal size fluorescent screen the of much capacity, shorten the aerial ; if too BATTERY the object. Magnifications up to tens of CONNEC- 1 little, lengthen it. For the receiving aerial, a TION$ I " thousands of diameters are possible. half wave length is recommended as su-

\Ml1 I li, 5" means of ' TICKLER perior to the wave. The usual I Quickly Made One -Tube Receiver tuning the set are employed. MIDGET When the radio set breaks down just before the big fight, you do not need to Regeneration in Superhets miss it. A box 2" x 4" will serve not only Far more effective than ordinary re- as the cabinet but as the coil form as well. 5 ceivers is a single signal receiver. One %d' The feed -back coil may be 40 turns of No. way of achieving this is to use a crystal ----'4V2,. TUBE AERIAL RIO CA T2 V4 40T. R.FC. - PHONES .i ,-+- -

500 MOM F. MMF / l 1Oi / \^ C7 -- 2 MEGS. ,as r B+ R9 20T - (--/ A+ R PHONES JACK 0 I MMF. mow CG 15 ONMS'

462 RADIO & TELEVISION

www.americanradiohistory.com RADIO REVIEW from World -Wide Sources

filter. Equally good and less costly is to add loading -this time by inductance. The typi- regeneration in the T.F. and R.F. In the i.F., cal example of this type would be an aerial regeneration works much like a regenerator having an overall length of approximately first detector. The standard 465 kc. trans- 6 feet, loaded with an 18 -turn inductance, former takes an additional winding of 25 air -wound to a diameter of about IA inches. turns of No. 33 D.S.C. jumble -wound in Cut -and -try methods on the aerial will be the same direction as the grid coil, and at its necessary to afford best response on 6% ground end. Fig. 5A shows the connections. meters. -Tcic '. & S. W. World (London). The feed -back coil is L3, with resistor R acting as a control. C4 prevents shorting the cathode resistor. Fig. 5B shows a system Latest Television Camera employed where no T.F. stage is included in The Super Emitron, a new type of the set. Fig. 5C shows cathode injection. 8 television pickup tube, which is now In making this change in your set, remem- being used for all outside broadcasts by ber that long leads or poor shielding will the British Broadcasting Co., represents a cause instability, according to "Television considerable improvement on the old type. & Radio Bulletin." Cathode feed -back in the A beam of electrons from a conventional 2 7i frequency changer stage is shown in Fig. electron gun G scans a mosaic .1/ similar -- -.I 5D where R5 is the regeneration control. to that of a standard Emitron, except that Electronic means of securing the same effect in this case the mosaic elements are not are also possible. photo -sensitive. In fact, the charge -storage electrode may now be a plain sheet of mica backed by a metal signal pl:.te. The Pump Keeps C. R. Vacuum High optical image is focused by a lens L onto Gilbert Seldes, dramatic director of a conducting transparent photo cathode P, 6 Columbia Broadcasting System's Tele- which is supported on a thin sheet of transparent I -, vision Division, is seen pointing at a pump material (e.g., glass or mica) -2'aJ which is connected to a metal cathode -ray situated close to a polished glass window W. 8OOHM -TWO METHODS OF FOLDING The light liberates photo -electrons from LINE le A SIMPLE HALF -WAVE tube. The end of the tube which bears the AERIAL- fluorescent screen has been removed and is the side of this photo cathode opposite to held in Mr. Seldes' left hand. This type of that on which it falls, these electrons hav- tube is made to be operated while under ing the same distribution as the light in continual exhaustion by the vacuum pump, the optical image. The electrons are ac- celerated by an and although it is not practical for a home electric field between the television set, it has various advantages in cathode which is held at about -500 volts, the laboratory. and the metal coating ß on the internal walls of the cylindrical glass tube T. This coating is an extension of the second anode Efficient Television Aerials of the electron gun, and both are held at ground potential. J As television approaches 7 more closely in Encircling the glass neck T is an iron- the United States, more thought must be clad magnetic coil C, which forms a mag- -A FOLDED HALF-WAVE AERIAL WITH REFLECTOR. given to compact antennas suitable for netic electron lens and enables the elec- apartment house installations. Fig. 7A shows trons that leave the cathode to be brought two means in which a simple half -wave to a focus on the surface of the mica dipole may be folded to conserve space. Fig. mosaic. These electrons liberate several 7B shows how a folded reflector may he secondary electrons each when they im- used with an aerial of this type. Such a pinge on the mica surface, and these sec- reflector will increase gain to a marked ex- ondary electrons now assume the same role tent. Fig. 7C shows still another means of as the photo -electrons that are ejected reducing antenna lengths. In this case, metal from the mosaic of the tube by light. Front plates are affixed to the ends of the dipole this stage onward the mechanism of -a forni of capacity loading. Twelve -gauge signal production is essentially the same is heavy wire enough to support such copper as that in the standard Emitron. -Television ^CAPACITY - INDUCTANCE plates. Fig. 7D shows another means of & S. W. World (London). LOADED AERIAL- LOADED AERIAL-

....__

.. = __ __ L3_ _ _ Al O 5 - 500 C3 MMF. 0- MF R Rt C2 L4 ÓMMS R5~ à+°M°s FIM S D

for December, 1938 463

www.americanradiohistory.com Freddie Bartholomew became so interested in radio The good ship "We're Here" -one of the finest schooners in American that he persuaded Radio Chief Matthew coastal waters-scuds across the sea as the radio waves direct her. Murray to help him try for a 3rd Class Amateur Phone License. How badia Helped to Film Courageous"

J. M. Goldby

The inside story of how a Radio Amateur made it possible for Hollywood to film a thrilling sea saga. Matt Murray and one of his assistants working the "We're Here" from their shack on the RADIO played an important rôle and and can definitely state that any company "Invader." added another new field to its already who attempts to shoot sea scenes without numerous uses when it aided in the filming the aid of radio will pay ten times the of the sea sequences of the motion picture, normal cost in money, time and aggravation Captains Courageous. For the first time for every one concerned." it became possible to take scenes which, A veritable floti:la sailed out of Los An- without the use of radio, would have been geles harbor for the open expanse of the much too dangerous to attempt. When the Pacific Ocean, deliberately aiming for the first previews of this film were shown to nearest storm center. Consisting of thirteen movie critics and to men versed in the sailing vessels, three tugs and sixty dories, technique of motion pictures, they thrilled this motion picture unit carried, in addi- to and marveled at the scene where the tion to its regular equipment of cameras, We're Here and the Jennie B. Cushman technicians, cast of actors and directors, almost collided during the race toward a little -known piece of apparatus especially their supposed port. This was one of the built for this job, plus the knowledge and hundreds of dangerous shots that was ability of Matthew Murray, ace Ham taken, made possible only because the pilots operator, W6OJL, and holder of a Com- Top of xmtr. 42's as oscillator and of both vessels heard the directions fired mercial First Class phone ticket. speech amplifier, 802 final stage, 6A6 at them by the Director instantaneously and When Director James Havens first con- Class B modulator; built -in genemo- simultaneously. Each skipper knew which ceived the idea of using radio in motion tor; 2 xtals; Collins network permits way the other was going to turn. It was a picture directing, he knew that some special use of any length antenna. Net weight, difficult and dangerous maneuver which equipment would have to be built to fit into 30 pounds. BELOW: Director ashore his specifications because of the unusual listens -in and directs action at sea. was arranged only by good radio equipment and efficient radio operators. work such apparatus would be called upon loot, i This was the consensus of opinion of to perform. Ml Beach, ES the entire staff of photographers and tech- L. W. McDowell of Long Calif., ` nicians who worked on the picture and is took all the requirements into considera- explicitly summed up by Mr. Lester White, tion and finally built the transmitter shown I ! Metro -Goldwyn -Mayer's Director of Pho- here into its compact casing, using but 30 I . tography for the sea scenes, "I emphati- major parts in the entire assembly. This l cally state that it would have been im- "rig," with an input power of only 10 possible to take most of the thrilling scenes watts, was able to put 80 microamps into at 1300 miles and at no SHORT WAVE and it would have been suicide to attempt KOU's antenna TRANS ANO RK. SET to maneuver the ships into such dangerous time was ever out of communication with AT SEA" Pedro station. It uses a 42 oscilla- MOVIE DIRECTOR positions without radio's aid! I've been film- this San IN HOLLYWOOD" ing sea sequences for the past few years (Continued on page 511)

464 RADIO & TELEVISION

www.americanradiohistory.com E ARMATURE COMMUTATOR ARMATURE MAGNETIC FLUX LINKS P.&S.COILS COIL COIL BRUSHES :::r e NPUT I si -. i tlJ. OUTD r A 1 C.i ... -:c ELECTRIC ELECTRIC (----- CBRUSHES SLIP RINGS PRIMARY IRON SECONDARY t R LIGHT LIGHT COIL (P) CORE COIL (5) FIG 1 FIG.2. (D C DYNAMO) FIG. 3 (A.0 GENERATOR) FIG.4 (TRANSFORMER)

Memory trick for Ohm's Law; D.C. & A.C. dynamos; and a transformer. 7Xe ni

How Electricity Is Generated

Martin Clifford, W2CDV and Measured

I N the first article of this series we dis- ance, we would just cover the letter R with and put it to use. This is done by connect- cussed such ternis as current. ?Pottage our finger and the answer would be E over ing the armature coil (as shown in the and resistance. It is no haphazard chance I. To Mid the current, we would cover the sketch) to a commutator. The commutator that these terms are grouped together, and letter I and the answer would be E divided in its simple forni is a copper ring, the two no accident or coincidence that a discussion by R (or E over R). halves of which are separated by a bit of of one usually involves the other two. Cur- At the close of the previous lesson we dis- insulating material. Since the commutator rent, voltage and resistance are directly cussed alternating and direct current -now is connected to the armature coil, it rotates related -for if we know any two of these let us see how these currents are produced. with it. In order to utilize the current in terms, we can always tind the third through the rotating commutator, we place brushes How Current Is Produced the use of a very simple, but exceedingly of copper mesh in contact with the com- have seen important formula known as Ohm's law. We already that a permanent mutator. \Ve can now light up a lamp by Briefly stated, Ohm's law (named after the magnet has a magnetic field about its poles. connecting it across the commutator We have also shown that if we took this man who first formulated it) is : brushes. To sum up-a D.C. dynamo may permanent and magnet, plunged it in and be simply a coil of wire moving in a mag- out a E E of coil of wire, a galvanometer con- netic field, plus a provision for leading the nected to E-I X R I - - R - - the coil would show a reading. If, current away from the moving coil by R I instead of moving the magnet in and out of means of sliding contacts. the coil, we moved the coil and kept the The generation of alternatin) current Since it would be very cumbersome to magnet still, the result would be exactly follows the same principle, except that two write out the words- voltage -current- the same. Here, then, we have the basic slip rings are used to draw off the current resistance in the formula, we simply sub- idea for generating . . . current simply instead of using a commutator (shown in stitute alphabetical letters for them. Thus, take a permanent magnet and revolve a coil Fig. 3). Naturally, the generators we have for example, we let the capital letter E stand of wire around it. shown are the simplest types imaginable. for voltage; I for current (in amperes In Fig. 2 we see the elementary prin- Modern generators do not use permanent and the letter R for resistance (expressed ciple of the D.C. dynamo. We are already magnets, but use relatively soft iron over in ohms). familiar with our old friend the permanent which are wound coils of wire (carrying We need not make any effort to memorize magnet. The part labeled "armature coil" current) to produce the magnetic effect. The this simple formula, since there is a very is nothing more or less than a of coil wire. amount of voltage and current that we can easy way of remembering it. Simply draw This coil of wire is mounted on a shaft. get out of our generator depends upon the a triangle. as shown in Fig. 1. Place the The shaft is not shown in the drawing since strength of the magnetic field, the size of letter E on top, the letter I in the lower is purely a it mechanical feature and need the wire, the number of turns that constitute left -hand corner and the letter R in the not concern us here. When the armature the armature coil, and the speed with which remaining corner. Using the triangle is not coil of wire starts to revolve between the we rotate the armature coil. at all difficult. To find the voltage, just cover poles of the magnet, a current of electricity the letter E at the top of the triangle with is generated in the coil. However, the cur- Transformer Action your finger -and you have the answer - rent in the coil would be of no use to us, Now that we have produced alternating I times R. If we wished to find the resist- unless we could in some way draw it off (Continued on page 500)

Schematic of transformer and three types of meter movements.

A C GALVANOMETER POINTER MAGNET GENERATOR SCALE

INPUT OUTPUT A

A A MOVING ilk COIL PRIMARY 1 COIL SECONDARY + NOT SPRING SOFT TWO DISSIMILAR WIRE ®g ",r IRON CORE IRON METALS (FIXED) FIG.S (TRANSFORMER) FIG.6 (THERMO GALVANOMETER) FIG.7 (NOT-IN/RE AMMETER) FIG.8 (DAR50NVAL /NSTROMENT) for December, 1938 465

www.americanradiohistory.com

_mi Shortwaves Featuredon SS."Nieuw Amsterdam" Below- Another view of radio cabin aboard Below -Radio cabin aboard the the "Nieuw Amsterdam." The operator is new Holland- America liner, the adjusting the speech volume control on the SS. "Nieuw Amsterdam" which is radiophone transmitter. equipped with Bell system ship -to- shore service. Operator is tuning the radio phone receiver. 6

Above -The palatial new liner -SS. Nieuw Amsterdam" entering New York Harbor. Note the comparative size of the tugboat and buildings.

p (Photos of radio cabin courtesy A. T. & T. Co., Long -lines Department)

THE magnificent new Holland- America liner, the Nieuw at 800 watts and can be operated on all wavelengths between 600 Amsterdam, features short waves to a great extent. One of and 800 meters (code). the accompanying photos shows one of the radio operators tuning The main receiver tunes to all wavelengths between 1800 and the Phillips receiver, while another photo shows a good view of 24,000 meters. the various transmitters on the ship. A short -wave transmitter (code), rated at 200 watts, operates The amount of radio traffic handled on a trip across the Atlantic on all wavelengths between 17 and 55 meters. on such a palatial passenger steamship as the Nieuw .4msterdam An emergency radio transmitter (code), of 100 watts rating, may be readily visualized, and the several transmitters are on can be operated on any wavelength between 600 and 800 meters. more or less constant duty during a great part of the trip across The ship-to -shore short -wave phone transmitter, for the use the ocean. Passengers can talk from the ship to shore at any of passengers, is rated at 500 watts and can operate on any time, thanks to the special radiophone transmitter with which wavelength between 16 and 90 meters. It is equipped with a the ship is equipped. special scrambler which renders the transmitted voice unintelli- The main radio transmitter on the Nicuw Amsterdam is rated gible if it should be picked up on any ordinary short -wave receiver.

Radio Talks from a Guiana Jungle Essequibo and Rupanuni rivers," said Hungerford, "and after we set up the radio shack we began to receive visitors. For a couple of weeks the most faithful of these were a group of Wai -wai Indians, who came to inspect the radio equipment and everything else we had. These Indians, who came decked out in their finest paints, must be the most curious people in the world. They didn't steal anything, but they did inspect everything around the radio shack. If there was something they didn't understand they'd simply break out in loud laughter. It took radio to make them serious. "The ringleader of these Wai -wai In- dians was a tall, handsome fellow. One night when we were working and our visitors were all gathered around I put the ear- "We were soaked, but we kept our date with 'On one occasion, a particularly vicious wasp phones on this fellow's head. Blank amaze- the radio audience . . and it gets cold bit me in the side . and my yell was ment. His eyes moved first to left, then to - heard coast -to- coast." even in the jungle!" right. I took the phones off a minute and he still stood there. All this time there was RADIO may be old stuff in the United never a word except those he heard through strange noises coming out of our receiver States, but the citizens in the interior of the earphones. He gave one final look while we were talking to NBC in New British Guiana still do not understand it, around the shack and then turned on his York. She looked first under the table, then according to Orison Hungerford, operator heel and walked out. All the rest followed up at the ceiling to find out where the of the Terry- Holden Expedition station in silence. And that was the last we saw voice was coming from. Then she went VP3THE, who relayed a series of proof our Wai -wai friends. They're probably outside and looked up at the roof. All of grams from the tropical jungle to the Na- walking yet. a sudden there was a loud wail. The only tional Broadcasting Company networks. "Then there was a little girl who came way we could stop her was to let her "Our camp was some 600 miles up the with her mother. She listened to the (Continued on page 485)

466 RADIO & TELEVISION

www.americanradiohistory.com RADIO fest ??

Meet Your Professor Robert Eichberg

Pit your brains against the best brains in radio! 5. If your boss told you to get him a 11. In putting up an outdoor antenna, Every month The Old Professor will back some he make a microphone, many radio men use stranded enameled leader in the radio field into a corner and test crystal so that could his general knowledge with the QUIZ. The expert he might tire you if you didn't come back wire because will not be given a chance to see the questions with a a. It looks better. in advance, or to look up the answers in reference b. does not so rapidly. books. There's no cribbing under The Old Pro- a. Rochelle salt crystal. It corrode fessor's eye. b. Galen crystal. e. It offers a greater surface arca. R. D. Washburn, Managing Editor of Radio- c. Quartz crystal. d. It is cheaper in the long run, as it 32 min- Craft, was this month's victim. After d. lasts longer. utes spent on the QUIZ, Mr. Washburne emerged Carboruudunt crystal. with a score of 82%';í and a slightly dazed e. Piero- electric crystal. expression. f, Silicon crystal. 12. You ought to b- e ashamed if you Now see what you can do. To calculate your rating, credit yourself with a`; for every ques- don't know that the intermediate frequency RAOiO PRESS PROGRAM CHIEF tion you answer completely right: 25; for every ANNOUNCER OE PARTMEHT OIRECTOR ENGINEER in a superhet is obtained by question you get half right, etc. Average scores a. Adding the frequency of the ineont- are: Beginners, under 50'; ;: Experimenters and ing wave to that of the locally generated Servicemen, 50 to 75', : Experts, 75 to 95r4: Wizards, over 95'4. oscillation. Which are you? b. Subtracting the frequency of the incoming wave front that of the locally gen- I. In the following list, one of the items erated oscillation. is as out of place as a tramp at the Ritz. c. Modulating the locally generated os- find it Can you and tell why? cillation with the envelope of the incoming a. Bleeder. 6. In broadcasting stations, which of the zcavc. b. Trimmer. following jobs pays the highest average d. Subtracting the frequency of the c. Oscillation suppressor. monthly wage? locally generated oscillation from that of d. Potentiometer. a. Announcers. the incoming wave. e. Volume control. b. Press agents. f. Rheostat. c. Program directors. 13. A rabid radio fa- n wants to send his d. Chief engineers. favorite star a birthday present. So whose 2, In most major broadcasting stations, birthday is which? a railroad is pro- the sound effect of train 7. Ignoring any othe- r advantages or dis- a. Bing Crosby A. Dec. 25, 1893 duced advantages, which may be inherent, which b. H. V. Kaltenborn B. July 28, 1901 a. By rubbing two pieces of sandpaper type of contact between a shaft and bearing c. Bob Ripley C. May 2, 1904 together. gives the best electrical connection? d. Lowell Thomas D. April 7, 1891 b. By making sounds with the moth. a. Pigtail. e. Rudy Vallee E. April 6, 1892 c. From a recording. phonograph b. Wiping. f. Walter Winchell F. July 9, 1878 d. the feet on a sounding By scuffing c. Sliding. board. d. Rolling. c 8. A photo- electric c- ell can be used to advantage in all but one of the following. Which is the outcast? a. Burglar alarm. STD. AGE CELL CELL 1 b. meter. Light WMAT IS ZHE VOL rAGE OF EACA, CFI t C. Television pick -up. d. Motion picture sound system play- rRF/H EFFECrS ARE PROOUCEO HOW J 14. Just to be unreasonable, let's hear back. you give the correct voltage of each of e. system recording. Motion picture sound these cells. 3. The tube charts list certain tubes as f. Smoke density meter. "general purpose tubes ", but which of these a. Clark cell. b. Standard dry cell. jobs can't you use them for, satisfactorily? 9. In the recent European unpleasantness C. Edison (alkaline) storage cell. a. R.F. amplifier. the Four -Power Conference) (just before d. Standard (lead-acid) storage cell. b. .4.F. amplifier. it was said that Radio was especially de- c. Power output. of mention as: serving 15. Maybe you're too young to have d. Detector. means for spreading propaganda. a. A heard of Jack Binns, but we oldsters re- e. Rectifier. b. A Means of international spreading member him as f. Oscillator. good will. pioneer in the use of ultra -short toward the preservation of a. A c. An aid waves. 4. Match tip the meters listed in one Peace. b. The first man to radio a call for help column with the items to be tested, in the d. Good for light entertainment, but from a sinking ship. other. nothing more. c. man to respond to a call a. 0 -50 ohms A. Power rectifier The first for output potential. help radioed from a sinking ship. -to radio b. 0- 50,000 ohms B. Filament potential d. The inventor of ship -ship of battery set telephony. c. 0 -10 volts D.C. C. Potential drop in bleeder. 16. The most efficient means of trans- d. 0 -10 volts A.C. D. Resistance of mitting high frequencies by means of wire <+i,vG S Fos 7 bleeder. /N7ERNAr/ONFL P.CCADCa NC/EO lines is c. 0 -1000 volts D.C. E. Filament rheostat a. Widely separated single wires. of battery set. 10. course you knew all along that b. Twisted pair. Of lines. f. 0 -1000 volts F. Potential across the purpose of a volume- expander is to c. Transposed cable. A.C. power trans- a. Make weak stations come in with d. Co-axial former second- more volume. e. Shielded wire inside grounded shield. ary. b. Increase the volume of all stations. is used in- g. 0-10 ma. G. Output to speaker c. Increase the apparent volume of loud 17. If a voltage doubler to voice coil. passages in reproducing voice or music. crease the voltage in a circuit approxi- h. 0 -10 amps. A.C. H. Screen grid cur- d. Increase the apparent volume of soft mately two -fold, a voltage multiplier rent in R.F. passages in reproducing voice or music. (Continued on page 490) for December, 1938 467

www.americanradiohistory.com Shooting Trouble on the Ham Transmitter

Alvin Abrams, \X/2DTT

Several interesting problems met with in operating transmitters are here described.

IN this article, the author will attempt upon modulation it was found that the an- dicating that the stage was apparently neu- to describe some puzzling conditions tenna current decreased and was therefore tralized properly. As a further test, the which have been encountered in transmitter not working correctly. The causes for neutralizing condenser was shifted to a servicing and the methods used to locate downward modulation were then reviewed random position and the amplifier condenser the source of trouble. These experiences and mentally tabulated. The first cause, once again rotated until the bulb lit. The have been garnered for the past six years, overloading of the amplifier, was discounted neutralizing condenser was then adjusted un- during which time the author has worked and rejected because the plate current was til the bulb went out. The setting of the con- on nearly every type set familiar to the normal, that is, at its calculated value. The denser was identical to the previous setting. radio amateur. No effort has been made second cause, inaccurate or off resonance The plate power was reapplied but still, heretofore to describe these unusual cir- tuning of the plate tank condenser. was upon modulation, the antenna current would cumstances which occur frequently and be- likewise discarded because the stage was decrease approximately 5 per cent, and cause they are so diversified and complex tuned precisely. The third cause, insufficient again when excitation was removed the in nature, they stimulate the curiosity and excitation was considered because it ap- amplifier would continue to oscillate. This are worthy of printed description. peared that the grid current was possibly a was extremely puzzling and annoying. As we know, all radio hand -books and shade too low. Connections to all tuned circuits were periodicals describe in great detail prosaic The first step to a solution was made checked and found to be in good condition,

6F6 0 -3 VOLTS A.C. DOTTED LINE s,OLTMETER INDICATES OPENED CONNECTED TO CIRCUIT. CRYSTAL PRIMARY X. DEFECTIVE CONDENSER -OPEN o A -6- i Ó X _ X Y Qßá. x r era LL1 cr 51 11051 -- 'I A. VOLTS PLATE MILLIAM- n V FIL. B+ B.1.000 - METERS OF OSC. TRANS. C.1.500 A BUFFER WOULD ,L5WTCH 125 V. FLICKER ALTHOUGH FOR SWITCH X WAS ábÒ `- 0+ MAIN i FILAMENTS + OFF. POWER . SUPPLY Left: Defective condenser problem -"X" marks the spot! Center: Plate meter "flicker" mystery. Right Test for "short- circuited" secondary; the exciting current is connected to the "secondary" for this test. transmitter troubles such as downward when the B positive switch to the exciter leaving only one possibility untried, that modulation, imperfect neutralization, distor- stage was accidentally disconnected and of a defective part. tion in audio frequency and radio frequency surprisingly enough did not trip the over- It was thought that the trouble was origi- equipment, although it will be admitted load relay in the circuit of the amplifier, nating from some portion of the tuning or that each case presents its own peculiar as would normally be the case when excita- neutralizing circuits. An ohmmeter was used problems. It is therefore hoped that the tion is removed from an automatically to check all condensers and showed that following will prove of inestimable value biased stage. With excitation removed, the they were in good condition, i. e. not when similar situations are met with. Here amplifier plate current did not flicker per- shorted. A 250 volt source was then used is a sample problem which will further ceptibly, and in fact, the amplifier was to determine whether possibly one of the clarify the type of situation referred to actually working by itself. Immediately, it condensers was open. All checked good with above. was thought that the stage was out of neu- the exception of one! This was a .002 tralization, that is, the tube was returning microfarad condenser used to isolate the Trouble from a Defective Cond part of the output power to the input, and rotor of the amplifier plate tank condenser The circuit involved consisted of a hence was in an oscillatory condition. from ground which was put in to remove single -ended plate neutralized stage with a A neon bulb was therefore coupled to the direct current potential between rotor balanced tank circuit. The amplifier was the tank and the B positive switch was shut and stator. It was temporarily shorted out neutralized and excitation and plate voltage off but excitation applied. The amplifier and the stage then worked to complete applied. According to the meters in the tank condenser was rotated throughout the satisfaction. circuit, it was functioning satisfactorily, but scale but the neon bulb did not light, in- (Continued on page 495)

468 RADIO & TELEVISION

www.americanradiohistory.com Radio New Experiments with Apparatus

Photo -cell Relay Each month we will award 2 prizes, up around the core. Place a coil of 150 to first, 2 Ist Prize -2 Years' Subscription -the years' subscription; 200 turns of No. 26 enameled wire, with a 1 flashlight A very sensitive photo -cell light relay the second, year's subscription bulb attached to each end of the for the best non -radio uses of ordi-- coil, over it. Current will then he induced is shown in the sketch. Distances up to nary parts radio coil of wire, and 150 feet have been covered with it. radio and in the small there will instrumentalities, be enough to light the bulb. The small coil of wire may be slowly drawn away, and the light will grow dim. primary coil, which is usually on the bot- This experiment demonstrates the action tom. Then wind on about 360 turns of No. of a simple step -down transformer. -John 22 wire, or larger, if there is enough space E. Hurley. in the core opening, and bring out a tap at every 60 turns. It is then connected as shown in the accompanying sketch to a QMP ATTACH HIGH - switch and any suitable regulator. VOLTAGE BH BELL OR With the SPDT switch in the low posi- BUZZER HERE tion, a range of from 0 to 90 volts may 110v. + be had. With the switch in the high posi- .001- tion, a range of from 110 to 200 volts may MF be had and both ranges are in 15 volt steps with only 7 contacts on the regulator. BALANCING These voltages will vary slightly if a trans- CONDENSER ÇONTROL former having a primary consisting of other POWER TRANSFORMER OUT F OLD 13' ELIMINATOR than a 4 to 1 turns to volt ratio is used. Simple Photo -cell and Relay Set -up. If the high range decreases the voltage in- Touching the control wire actuates the alarm stead of increasing it, connect the primary The cell can be almost any photo -emissive to the other end of secondary, thus reversing Burglar Alarm type. The relay should he capable of operat- the connection. THE accompanying diagram shows a ing on a variation of 1 mil. Pure D.C. is I have found this transformer particularly simple yet effective burglar or thief not necessary, so the 8 mf. condenser suf- useful in varying the speed of small fans, alarm. This hookup makes use of one of the fices for the filter system. The 20 megohm boosting the line voltage, and testing and BH rectifier tubes. The alarm is set off resistor is very important : any substitution experimenting in general around the shop. by touching the control wire, as shown in (unless it is of a higher value) will result The transformer, regulator and switch may the diagram ; this has the effect of increas- in a decrease of sensitivity. A 360 ohm re- all be assembled in any suitable container ing the capacity on that side of the circuit. sistor in the power cord provides the neces- for convenience.-Clarence H. Cramer. Practically the only current consumed by sary voltage drop for the filaments. the device is the slight loss in the trans- To put the unit into operation, the poten- former core and windings. A relay may be tiometer is adjusted so that, with the light used with this circuit, if desired. -W. L. source focused on the cell, the relay is just FLASHLIGHT 150 TO 200 TURNS Reemes. barely closed. Then when the beam is inter- BULB NE. 26 ENAM. WIRE rupted, the relay will open. For invisible Two- timing a Chime! beams, a piece of red cellophane can be A "MELLO- CHIME " -a musical door- placed PRIMARY ',SECONDARY over the light source. This reduces bell which chimes only once when you the maximum distance of operation y NOT u5ED to about press a button, can be made to chime twice ten feet. - once when the contact is made and again The light source used by the is a author TO 1foV.. when it is broken. The current flows into 21 candle -power. 6 volt auto headlight bulb, FUSE A.C. \ the chime's coil at the moment the button mounted in an old box camera with a small completes the circuit ; the radio conden- and transformer a one -inch lens. -Bill ser receives its current by Jakes, Jr. charge surge action as the field about the chime coil i-st VT. collapses and the magnet discharges its Line Voltage Booster / METER stored energy into the condenser, when 2nd Prize -I Year's Subscription OR LAMP the button is opening the circuit. The con- HERE'S a new use for an old power \_JL denser then discharges its energy back to transformer, if the primary is still in the coil, where it is spent in a final effort good ACTION OF to pull the chime pole condition, which is usually the case. TRANSFORMER against the musical Take all the windings off down to the DEMONSTRATED bar or plate. -Willard Moody.

TO 110V "CUSTOMARY ARRANGEMENT" o A.C. MELLO- 4' ADDITIONAL PAPER Old audio or other transformers prove useful CONDENSER for "induction" demonstrations at clubs, etc. r-

I I Demonstration of Transformer L_J BUTTON I Action 1 CL= I SUBMIT the following device for your contest. It is part of the iron core of an old Audio Transformer with its wind- VOLTURCE (2 DRY CELLS) ings. By putting 110 volts through the Transformer rig to boost line voltage. primary section of the coil, a current is set Adding a condenser gives chime 2 tones. for December, 1938 469

www.americanradiohistory.com The Short Wave League

HONORARY MEMBERS Dr. Lee de Forest Manfred von Ardenne On the Ham Bands D. E. Replogle E. T. Somerset John L. Reinartz Hollis Baird (with the "Listening Post" Observers) Hugo Gernsback, Executive Secretary Edited by Elmer R. Fuller

AS soon as it can be compiled, a list of Len Carling- Observer for Illinois According to information received from Observer Hartzell. either United States or New Zealand the stations which are known not to verify Call Freq. R S Call Freq. R S stamps may be used for return postage front reports will be published. If you know of VK3EH 14.060 4 7 VK4HN 14.295 3 4 VR6AY. The ORA is Amateur Radio Station V P3AA 14.085 5 8 VP7NU 14.045 5 9 VR6AY, c/o Andrew C. Young, Pitcairn Island. any such, please send me their calls. VK2OG 14.100 4 6 VP7NS 14.100 5 8 Once more, I must ask you to report CN1AF 14.275 4 7 K6FKN 14.234 5 8 only good DX according to the standard PAO W N 14.265 3 5 K6ILW 14.198 5 8 L F. Gallagher-Observer for New York K5AH 14.260 5 7 VP7NC 14.252 5 8 Call Freq. R S Call Freq. R S VK3ED 14.300 3 5 G8UY 14.020 4 8 VK4VD 14.310 4 6 G6NI 14.100 5 7 rt(MP .- Ill sll:c Inll, PP I Al rarr. VK2QR 14.290 2 4 G2UF 14.150 3 7 ". .u.pr -n t>q VK4JU 14.350 4 8 G5NI 14.110 5 8 pIIN (Bs vuu VK2AIZ 14.270 3 8 VP3AA 14.350 5 7 u\ I(!\I.I,A VK2QI 14.300 3 4 VP7NS 14.030 5 9 VK3EK 14.270 5 4 VP5IS 14.310 4 8 VK3UC 14.310 4 9 VP6F0 14.300 5 7 JOHN w n ru or SI lRlll t\ I1.1 P. rT,JJni VK2ADD 14.300 3 6 PK2AY 14.300 4 7 VERSFELD , \ II It l. VK2AGT 14.320 4 6 CN1AF 14.300 5 9 Nt I. G5MF 14.000 5 7 CT1QA 14.300 5 8 P.O. COnïl.\rOA, CAPE TOWN, South Africa. Tom Jordan-Observer for Pennsylvania N17.5'r::r. I.,t. Call Freq. R S Call Freq. R S oll EA9AH 13.992 5 9 Rdo VOIT 14.225 5 9 Malaga 14.440 5 8 If you ever contact Mr. Versfeld, you'll get KSAH 14.200 5 6 one of these for your collection. John Fitzpatrick -Ob for New Jersey Call Freq. R S Call Freq. R S The QRA of VP7NC is P. O. Box 703, VR6AY 14.340 4 9 GM6RG 28.210 4 7 Nassau, Bahamas. CNIAF is at Tangier, V K 2OH 14.110 4 6 K4FKC 28.200 5 8 Recognize your favorite magazine in the hand PK6XX 14.350 3 4 K4EZL 28.210 5 8 International Zone, North Africa. The ex- VK4VB 14.135 4 6 GSBM 28.205 3 6 of John Versfeld Klaasenbosch, Town, of Cape act QRA is not known here, but an attempt HR5C 14.240 5 9 Ef2L 28.200 4 7 P. O. Constantia, South Africa? He has logged will be made by yours truly to find it, and JI 14.030 4 4 W7GGG 28.225 5 9 350 S.W. and B.C. stations, and more than 400 vth.'1JC 14.010 4 6 report it as early as possible. CN8MV 14.050 5 7 Hams in 53 countries. Ernest W. Lang- Observer for Washington C. R. "Pat" Patterson- Observer for Georgia Call Freq. R S Call Freq. R S Call Freq. R S KAIBH 14.110 5 6 KAICS 14.310 5 5 VP7NS 14.05 5 9 which was outlined in the October issue. KA7EF 14.140 5 8 KAIJM 14.260 5 7 Thus far, fifty -seven observers have been KAIHS 14.280 5 6 KA1FT 14.100 5 6 appointed throughout the entire world. Elvyn L Barker-Observer for Maine Every continent except Australia and South Howard Kemp -Ob for Connecticut Call Freq. R S Call Freq. R S Call Freq. R S Call Freq. R S VP7NS 14.15 5 9 VR6AY 14.35 4 5 America is represented. Our farthest ob- 14.13 4 5 PK6XX VP6FO 14.08 5 8 VK3WA 14.277 5 6 .CX2AU 14.20 5 7 VP6LN 14.04 4 7 14.23 4 server from this location (Cortland, New VP5IS 14.08 5 8 VK3HG 14.035 5 5 CNIAF 6 VP1BA 14.19 5 7 PAOMZ 14.10 5 7 York) is Ifasud Akhtar of New Delhi, K4FCG 14.18 5 8 VK2LC 14.05 5 4 India. Mr. Akhtar read this department VP3AA 14.075 5 7 K6KMB 14.21 5 7 KSAR 14.234 5 7 K6AIU 14.188 5 5 Burns E. Hegler- Observer for Kansas in the September issue of RADIO & TELE- NY2AE 14.190 5 7 VR6AY 14.346 5 7 Call Freq. R S Call Freq. R S VISION. VP1 BA 14.13 5 7 PK6XX 14.01 5 5 YN3DG 14.26 5 7 VK3HG 5 8 SV1KE 14.025 5 7 VK2MH 14.127 5 5 14.- First this month we will hear from A. R. PK6XX 14.02 5 8 TG5 5 9 ON4AM 14.120 5 6 VK2ABK 14.087 5 6 14.- VP6LN 14.01 - - NY2AE 14.- 5 8 Rowley, observer for the Republic of CTIOO 14.143 5 6 VK5KF 14.115 5 6 Panama. Mr. Rowley has just received SU1KG 14.04 5 6 VK4JT 14.035 5 6 (Continued on page 488) CN8NA 14.10 5 6 K4EZR 28. -- 5 8 permission from the government of Panama CN8MA 14.09 S 6 to own and operate an amateur c.w. sta- Here's B. Takars of Kispest, Hungary. His call tion on the 20- and 40 -meter bands. And Charles H. Fuller -Observer for your editor now, is is now HA5C. here his report: Call Freq. R S Call Freq. R S VK3BZ 14.150 4 6 C3FA 14.125 5 6 Call Freq. R S Call Freq. R S VP7NS 14.175 5 8 G6GF 14.200 5 7 W6PER 14.20 5 9 JSAH 14.33 4 6 G5ML 14.175 5 7 CX2AK 14.090 5 7 W6NI X 14.25 5 7 ZL2BE 14.05 5 6 G2AI 14.175 5 6 GS N 14.150 4 7 VK2NQ 14.35 5 6 W7BJS 14.35 5 7 GM8RJ 14.175 5 6 0G6JL 14.300 5 6 EA9AH 13.99 4 5 VP7NH 14.15 5 9 G6AG 14.180 4 6 VP7NU 14.100 5 6 G2PU 14.09 5 7 EI8J 14.200 5 7 G2TR 14.150 4 6 G8LP 14.200 5 6 William Dean Noyes- Observer for Nebraska Call Freq. R S Call Freq. R S Clarence Hartzell- Observer for Pennsylvania VK2ABD 14.12 5 9 VK3XP 14.10 5 8 Call Freq. R S Call Freq. R S VK2ADT 14.06 5 8 VK3ZX 14.02 5 9 VP1BA 14.112 5 8 TI3AD 28.290 5 6 VK2AJU 14.11 5 8 \rx4JP 14.05 5 9 YN1OP 14.307 5 8 HI7G 28.310 5 8 VK2EII 14.10 5 9 VK4JU 14.15 4 6 VR6AY 14.346 5 8 G6DT 28.200 2 3 VK2HX 14.11 5 8 YV1A 14.00 5 9 PK6XX 14.000 4 7 G8M? 28.426 3 3 VK2JN 14.33 3 5 YV4A 14.08 5 9 NY2AE 14.210 4 6 G2KU 28.590 3 4 VK2IJC 14.10 5 9 YVSABQ 14.06 5 8 VP6FO 14.091 5 7 G6BH 28.230 4 4 VK3AZ 14.12 5 9 K4EJF 14.24 4 8 VK2UC 14.090 5 9 G2MI 28.270 5 6 VK3BZ 14.15 5 9 K4FAY 14.21 5 9 VK3PE 14.030 5 7 G8TD 28.340 3 4 V K3 ED 14.11 5 7 K6ILW 14.21 5 8 VK2HF 14.270 4 8 G5BM 28.348 2 4 VK3ES 14.10 5 7 K6OJI 14.17 5 9 VK4VD 14:146 5 -9 GM6RG 28.430 5 8 VK3PB 14.05 5 7 K6OQW 14.23 5 8 K7AFC 14.165 5 8 F8UE 28.390 4 4 VK3OR 14.14 5 8 SU1CN 14.300 3- 7 EI2L 28.290 3 5

470 RADIO & TELEVISION

www.americanradiohistory.com Loyal HAM Gossip

Brunswick, Ga. know him as he is our ARRL Director. and is doing his best for us.- Albert C. tithe, W2JZO. THE Hams of Brunswick and Saint Simons Island. Georgia, have formed a club which will further the activities of all who are members and Rocky Mountain Division News those who join later. The primary cause of the THE 12th ARRL Rocky Mountain Division formation of the club was their interest in their convention has come to an end and through community in case of an emergency. the assistance given by RADIO & TELEVISION to The amateurs formed a governing board, electing make this convention a success, "ham" radio has a president, secretary- treasurer and vice- president. again gone a step forward. In ten weeks the club grew to a membership of No expense was spared to give every one attend- over twenty -five. including hams who operate the ing his money's worth and yet not place the burden twelve or fourteen stations located in this area. of such expense upon those who had no particular There are two radio engineers included in the interest in such a gathering. Only through your membership, Communications Engineer H. T. whole- hearted cooperation was this possible. The Adams and Radio Engineer Morgan, along with attendance at the convention speaks for itself, in a ham of long standing. A. R. Bates. manager of the amount of interest created, by the fact that the local Western Union, who is president of the the paid registrations exceeded those of any Rocky organization. Mountain Division convention held during the The members of the club have attended regularly - past few years. -San Isabel Amateur Radio Assn, spaced code schools, where the beginners have E. S. Buchanan, Activities Mgr. learned the fundamentals of code and another where the more- advanced code -students have had an opportunity to improve their speed. This VI. is 14- year -old Betty McConnell, daughter Buffalo News Application has been made for a charter in the of Roy E. McConnell, Chief Radio Engineer of DURING the fall and winter season, several Amateur Radin Relay League. and favorable Police Radio Station W9XEH Evansville, Ind. The local organizations will offer instruction in action is anticipated by the members of The Bruns- station is her OM's ham rig, W9HBS, using a amateur radio; continental code and general radio wick Amateur Radio Club on this matter. 6L6G oscillator, an 807 doubler, a 755 buffer and a theory. The first unit to announce schedules for They plan to build a club-house transmitter in pair of 755's running 350 watts in the final. Speech titis instruction is the radio division of the local the near future where the touring hams can visit equipment includes a crystal mike into a 57, resist- Boy Scouts. with the members of the local club- -J. E. Joines, ance-coupled into a 56, transformer -coupled to a A six-month radio course is being offered at the P. 0. Bo.r 17 :, Brunswick, Georgia. pair of 56's, into a 500 -ohm line to a pair of 2A3's Sea Scout base at the foot of Porter Avenue. This and a pair of 830B's as modulators. It works all instruction is for scouts interested in radio and bands on phone or c.w. In the floods last year it includes continental code as well as practical and Amateurs Active during Boston Hurricane was on the air for 408 hours without signing off, theoretical radio. and was a frequency the Na- BOSTON hams had a busy time of it during given special and Jack Vom Scheidt, skipper of the local radio and after the semi-tropical hurricane. tional Guard call letters LC9E. division. will serve as instructor. Further details At 6:20 p.m. the electric power at \\'IAFP, of are available at Boy Scout Headquarters, 110 Hyde Park, went off. One of the first hams to Franklin St. have electric service restored. IAFP had his tower The question "flow short is a short wave ?" has line repaired by 2:00 p.m. on the 22nd. three weeks after he moved out there! W2GRC for years challenged amateurs to investigate the \\'IAFP regularly operates on 5 meters. but has passed the century mark when it comes to possibilities of these ultra short wave transmissions. none of the "local" boys seemed to have their working countries. with \\ -2l KV a close runner -up During the coming tests. another step is being power as yet. So. a hastily built -up 210 Hartley with 77 and still going strong. \V2JEH must have taken to check the behavior of the extreme short oscillator was put on 40 meters. Not Hutch traffic a warm slot in his heart for the sunny South. waves. A one quarter meter transmitter is to be was handled, however, since few stricken areas W2JIL, front the wilds of Brooklyn, seems to Aerated and an attempt made to send a signal had electric power. Relaying was difficult because have the technique when it comes to the making of front Colden to Buffalo. This is the first time that of skip, and also because power lines were down contacts. He gets what he is after. W213\VE be- any opte quarter meter transmissions have been all over New England. lieves in building his own HRO receivers. Says radiated during the high frequency field tests. However. when the electric service was restored that they pull in more DX. It must be in the way Experimenters in Buffalo are asking to report at \\'IPI. and at Hyde Park. late in the after- that he polishes his tubes! \V2KBG made quite a upon results to Leon Ryker of 228 Jewett Ave. noon of the third day, real action began. IAFP record for herself on five the past summer. "DX Canadian amateurs should report to Harry Lang went over to IPI's shack to help handle traffic or nothing." so Sally says, and DX it was! of 33 Lessard Ave., Toronto. and amateurs in that had been pouring in for two clays. Operation The five meter hand is becoming almost as remote New York, Pennsylvania and Ohio areas was carried on 5, 80 and 160 meter pitone and crowded as the twenty meter band and not with should report to Robert T. Schlaudecker of 2424 C.W. An emergency net was formed with W'ISS. flea -power transmitters either. Kilowatt lobs are Taggert St., Wesleyville, Pa.- Conrad J. Klauk, \ \'lKVJ and W5CSU. Traffic was relayed on not uncommon. with 200 to 300 watt transmitters 418 Perry St., Buffalo, N. Y. 5 meters to W5CSU who sent it on over 80 meter taking the lead. This may seem funny to some c.w. at the key of WIMX, at the Mass. Institute of you but one of our local hams with 0.1 (1 /l0) "Hudson Division" News of Technology. In addition, \VIKRI. handled watt into the antenna has been working some real traffic for points south and west on 160 meter DX on five meters! W2IKV phone. Other cooperating hams. included among Two and one -half meters seems to be almost TIIE summer months saw a great deal of re- whom were WI H LW. WIJPX. 1\'IAGR and as active as five meters. and I believe it is a building, and also many new antenna structures. \ \'IJSV. kept their local channels clear for mes- better band for short distances. Less QRM and Several rotating arrays are now in operation, sages intended for their areas. more DX. You will need a 2!/, meter antenna for with their users quite gratified at the results Operating portable mobile were \VIJDO. WIJLI "rubbering in" on that band if you are expecting obtained. Rumor has it that one of our better and \VIFTR, on visit from Hartford. Conn.. who to give it the once -over. Don't pass it up if you known 5 -meter stations is planning an elaborate picked up plenty of local 5 meter traffic and actu- have a receiver that will go down that far. rotating beam array for use with the new 300 ally delivered the messages, driving right up to the The "73 Club" here in the Metropolitan District watt transmitter he is building for the 56 mc. band. doors! Many other hams. not mentioned above. is doing a fine piece of work. When it comes to The past summer saw considerable portable mobile also rendered valuable assistance. interesting meetings, they have them-discussions and mobile marine 5 -meter work. In fact. one sta- The Boston Police Department telephoned many and lectures by men who know their subjects. They tion was so scared at working a 56 mc. marine messages to \VIPI, for retransmission. since tele- give the Ham what will help him most; they also station that he, the land station, believed it was phone lines outside the city were down. In fact. IPI help him with his individual problems. Something the F.C.C. finally catching on to him, for sure. had police department messages waiting for trans- interesting for hams at every meeting is their aim. (Wonder why he had a guilty conscience ?) The mission before his electric power was restored. We are wondering what has happened to the Hud- bootleggers continue to flourish, and it is too bad Most of the police department messages were of son Division Radio Phone Association. Did it get that the amateur bands, already so crowded. can- a personal nature, as Boston residents phoned the lost in the local QRM? Ken Hill gave us some not be rid of this nuisance. police, asking them to forward messages to rela- very fine meetings last Winter and Spring. You To those of you who are really interested in tives or friends in stricken areas. The police then your bobby let nie repeat. now is the time to relayed to WI PI. devote some serious thou ht to the problems con- A vote of thanks is due to Mrs. \\'1PI. who fronting amateur radio. For your own good, as hour after hour fed the boys with hot coffee, cake. well as that of your fellow amateur. do some- pie and sandwiches. And all that helped them to thing constructive, in the form of electing a carry on from 5:00 p.m. Friday until Monday at suitable director, who will represent you and your 2:00 a.m. with only 8 hours of sleep in the whole club and your division. Join the League, become 57 hour stretch. affiliated with your local club, and stake this one It is conservatively estimated that 2000 messages New! Exclusive! of radio's most memorable seasons for yourself were handled. After that, with every message and fellow hams. 73 es BCNU.-Llewellyn Bates cleared out. they called it a "night." and hit the Keim, W2IKV. hay at 3:00 A.M.-J. A. Schindler, WIIZH. South Bend, Indiana, Activities 21/2 5 Bands Active and Meter THE South Bend Amateur Communications W2JZO Roster of Society president is Herb Cole. Chief Engineer ID TRAMPING up to the North Pole would prob- of Tribune Stations W-SBT -WEAM. He obtained ably have been an easier task than to get a our present clubrooms for us. with facilities for completed OSO from the Metropolitan area this 200 or more. Plans are being made to form a summer. QRR\I and more QR\I seems to be the club- network with a key station to take care of rule. cross-communication and to maintain regular Apart from this, however, some interesting New HAMS schedules. The club's Vice- President is Francis things are taking place. W-2AU. with a close - Bock. Chief Operator of the local police station, spaced home -made beam antenna and 300 watts. \VPGN. Don Vary, W9ZTG. is our publicity man. seems to be taking all the laurels away from the He writes a weekly column called "CQ" in the "Kilowatt boys" when it comes to putting signals Tribune. W9KOE. Irwin Hoffer is Treasurer. into the ether. W'AC (worked all continents) with- See Page 493 \V9PUS. is the Secretary. in twenty -four hours after the beans went up W8QJN. a WAS -\VAC man. has moved back Elmhurst must be a Ham's paradise as W2IHX to his place in Mishawaka. Ind.. where he has worked more than one hundred Europeans within (Continued on page 483)

for December, 1938 471

www.americanradiohistory.com What Do YOU Think?

, ;-=-=T,

Photos above show the high -quality transmitting and receiving equip- for use on this band. He uses a "one to ten" meter National receiver. ment and the antenna mast at station ON4AP, owned and operated One of the receivers used is a Super SkyRider. The transmitter panel by Rob. Godefroid, 23 Rue Basse, Audenarde, Belgium. Mr. Godefroid construction will provide some new ideas for American Hams. The is particularly interested in 5 -meter work and he has special antennas station transmits on 80, 40, 20, 10 and 5 meters.

Wants 3- to 6 -Tube Receiver Data ham,' Tiverton Road, Plumstead, South An English "Ham" Greets Us Africa, has now been allotted new call let- Editor, I have been a reader of S.W. &T. since ters Z S 1 (one) When I last heard about the old "ogre viz: C O" (ZS1CO). 1934, and have hardly missed month W. T. D. MURRAY, a since. of the ham bands," he was going to gobble I think your magazine is about the best all - up a few smart young "squirts." His % S. A. Police, hallu- DEEP RIVER, Town, round one available-it has something for cination was truly remarkable for a man of via Cape everybody -Ham, S.W.L. and Experimen- his mental capacity. He must have had con- South Africa, ter. siderable experience with the bootlegging Last year I received my amateur license racket as he seems to know all about it. I'll and am now active on the ham bands. bet that no one ever gave him any R -9 W8QKA Ham Station at Parma, Ohio The transmitter here is a CO- FD -PA, reports! using American tubes, 47 crystal oscillator, QSLing is a great sport. It stimulates the '10 doubler, and a 801 in the power ampli- growth of "hamdom" and makes people fier, running 10 watts input. This is on 40 more interested in S -\ \ operations. The meters. For 20 meters I use a single '10 hams have contributed much to radio by tube in a Hartley circuit, with about 7 continuous experimenting and yet Mr. watts input, and this has worked fine for Fiege condemns them. DX, considering the low power. Up to the Now for some brickbats. Whoin'ell builds present I have worked 38 countries in 3 nine to twelve tube superhets? Not many continents (Europe, Africa, and North fans who want real DX build one and two America), DX includes W- 1- 2- 3 -4 -8, VE1, tubers. This magazine is supposed to be SU, U- 1-2- 3- 4 -5 -6, CT2, FA, CN, etc. for the advanced fan as well as the begin- I like Joe Miller's department very much ner. I think that three- to six -tube receivers and always enjoy reading it. Keep up the and medium -power transmitters are more good work. Joe! I would like to see a short appreciated. article each month dealing with C. W. DX Live up to your motto of having the radio heard and worked on the amateur bands, so experimenters' magazine. Print more con- what say? (See "On the Ham Bands" in structive articles. Tell those, who don't the S -W League Department. Editor) know, how they may become amateurs and In closing my letter I will say how much how to learn the code. R. &T. has helped me in the past, espe- Now for some bouquets. There are sev- cially when studying for my amateur li- eral good columns hut the S -W kink and cense, 73. the Joe Miller departments are about tops. HARRY TEE, Many times I have referred to the kinks The photo above shows the Ham station of (Amateur Radio Station G8UA.) printed in your magazine for aid in solving Joseph Horvath, W8QKA, 3710 Wellington 104 Rectory Road, S -W problems. Ave., Parma, Ohio. Receiver used is a Na- BURNLEY, Wishing you 73 and hoping that more tional AC -58 and the power supply unit is Lancs., ENGLAND. good work is begun. home -built. The transmitter at the left of the JOHN GEARY, desk is a 6L6M crystal trite+ with a 10 final R.F.D. 6, Box 719, amplifier. The frequencies used are Thanks for the Suggestions Phoenix (the land of the SUN), 3633 and 7266 kc. Editor, ARIZONA. I have been interested in short wave radio some New South African Calls for time and at present have a 5 -tube home-built set, on which I have Editor, heard stations in over thirty countries. When you in 20 or 40 tune on meters DX Joe Miller's department is very fine. The and happen to hear an amateur with a new station list should not be spread through the call sign -inter alia-South Africa, do not magazine, as this is highly inconvenient; the think you have logged someone new, no, not Question Box should be given at least two in the least; it is only an old one which pages. I prefer articles on small experi- you perhaps have already in your log book. mental sets. The following letters have been allotted to I believe the collecting of QSL cards can the Union of South Africa, viz : ZS; ZT ; be as interesting a hobby as radio itself. My ZU with Divisional numbers and individual friends and I would like to see more letters letters. of the type that Mr. Fiege wrote. His The prefix Call letters ZT and ZU will "clowning" and the subsequent answer of no longer be used by South African ama- his many "admirers" gave us all a big teurs, and a general revision of Amateur laugh. It is he who should dig a hole and Call Letters in South Africa has taken crawl into it -that is, if he is able to. Hi I place, and new call letters allotted; e.g.: H. G. DINACKER, "Z U 1 V-Mr. G. H. J. Sadler of 'Cul- An English "Ham," Harry Tee. G8UA. Reading, Pa.

472 RADIO & TELEVISION

www.americanradiohistory.com This beautiful silver trophy stands 111/4" high and is to be awarded monthly by RADIO & TELEVISION magazine for the best photo of a Ham station. The silver statue stands on a handsome bakelite base on which is a silver plate. The name of the winner will be engraved on this plate before the trophy is sent to him.

SIXTH Silver Trophy Awarded to &dwatd q .chmeichet W9YFV Chicago, III.

Here's the rig that reached 265 hams in 40 countries, within 60 days. The man who built and works it stands beside it.

THE transmitter built by Edward Schmeichel at W9YFV is a home -made job but is comparable in appearance and performance to commercial apparatus. "The line -up," says Eddie, "is an RK49 tritet (using six variable gap crystals), 807 buffer doubler, a T55 buffer link coupled to a Taylor T155 in final, running 600 watts input on all bands from 10 to 160 meters." Frequently Mr. Schmeichel works on phone; the speech equipment used includes a Turner cell type crystal mike, a 6C6 Eddie Schmeichel, of the The other half of the winning station -heré s pentode, 76 second speech, 76's push -pull, the receiver that picked up all that "round - and 6A3 drivers coupled through a 500 ohm Windy City, wins the Silver the- world" DX for Eddie. line to four TZ20's in push -pull parallel. Trophy this month for the The final stage normally runs at 3000 volts best Ham Station photos. your station photo is selected as the best on c.w. and 200 volts on phone. The output of those submitted each month, you will be is fed into a 99 -foot end feci Hertz antenna Have you entered a photo awarded one of these handsome silver which is 75 feet above ground. One inter- of your rig yet? trophies with your name engraved on it. esting feature of the setup is the use of a The trophy stands nearly 12" high and D.P.D.T. relay to switch the antenna from is a fine example of the silversmith's art. the transmitter to the receiver. The trans- sidered by fellow Hams as "a distinct We are sure that every Ham in the country pleasure to listen be he should win it. mitter readily uses break -in and push -to- to." will tickled with it, if The silver trophy represents the spirit of is controlled by relays Mr. Schmeichel adds "I have been a con- talk, and entirely victory and it was designed by one of the from the operating position. sistent booster of SHORT WAVE CRAFT (the former name of RADIO & TELEVISION) and leading silversmiths. The name of the win- The receiver is an RME69 with a built - ner month be engraved on a silver owe my start in short waves to this maga- each will in noise -silencer and a DB20 preselector. plate mounted on the black bakelite pedes- The transmitter was completed in time zine. Vy 73 de W9YFV." tal before the trophy is sent to the success- (Mr. Schmeichel's address is 2968 S. for the last DX contest, and in the sixty ful contestant. days between March 5th and May 3rd, Loomis St., Chicago, Ill.) The next award will be announced in date 1938, young Mr. Schmeichel made 265 the February issue, and the closing for that contest is December 10. The judges DX contacts in 40 countries, scattered over Rules for Trophy Contestants of the contest will be the Editors of RADIO continent on the face of the earth. every WOULD you like to win one of these & TELEVISION. In the event of a tie, dupli- According to reports received from all beautiful silver trophies? It is very easy cate prizes shall be awarded to the con- over the world, W9YFV has beautiful qual- to do so- simply send the Editors, a good, testants so tying. For further details sec ity on phone, and its note on c.w. is con- clear photograph of your Ham station. If page 315, September issue. for December, 1938 473

www.americanradiohistory.com World Short Wave Stations ZvLed /11cnth11 Complete List of SW Broadcast Stations

Reports on station changes are appreciated.

Mc. Call Mc. Call Mc. Call 31.600 WIXKA BOSTON, MASS., 9.494 m., Addr. 17.810 TPB3 PARIS, FRANCE, 16.84 m. Addr. 15.260 GSI DAVENTRY, ENG., 19.66 m., Addr. Westinghouse Co. Daily 6 am. -I (See 15.245 roc.) 9.30 -11 am. (See 17.79 roc.) 12.20 -1.30 pm. am., Sun. 8 am. -I am. Relays 17.800 TGWA WBZ. GUATEMALA CITY, GUAT., 16.84 15.250 WIXAL BOSTON, MASS., 19.67 m., Addr. m., Addr. Ministre De Fomento. University Club. Sun. 10 am. -12 n. 31.600 WIXKB SPRINGFIELD, MASS., 9.494 m.. Irregular. 15.245 TPA2 Addr. Westinghouse Co. Daily PARIS, FRANCE, 19.68 m., Addr. 17.790 GSG DAVENTRY, ENG., 16.86 m., Addr. 98 Bis. Blvd. Haussmann. "Paris 6 am: I am., Sun. 8 am: I am. B.B.C., London. 5.45 am. -I2 n., Mondial" 6 -11 am. Relays WBZ. 12.204 pm. 15.230 HS8PJ 31.600 W3XEY BALTIMORE, MD., 9.494 m., Relays BANGKOK, SIAM, 19.7 m. Irregu- 17.785 JZL TOKYO, JAPAN, 16.87 m. Irregular. larly Mon. WFBR 4 pm 12 m. 8.10 am. 17.780 W3XL BOUND BROOK, N. J., 16.87 m., 15.230 31.600 W2XDV NEW YORK CITY, 9.494 m., Addr. OLRSA PRAGUE, CZECHOSLOVAKIA, 19.7 Addr. Natl. Broad. Co., 9 am: Col. Broad. System, 485 Madison Addr. (See OLR4A, 11.84) 8 pm. Ave. Daily 6 -1I pm.; Sat. and Irreg. 7.55 -10.55 pm. 17.770 PHI2 Sun. 1.30 -6, 7 -10 pm. HUIZEN, HOLLAND, 16.88 m 15.220 PCJ2 HUIZEN, HOLLAND, 19.71 m Addr. (See PHI, 11.730 mc.) Daily 31.600 W9XHW MINNEAPOLIS, MINN., 9.494 m. Addr. N. V. Philips' Radio Hil- 7.40 -8.40 am. Tues. and Thurs., Relays WCCO 9 am. -12 m. versum. Tues. 2 -3.30 am., Wed. 7.25 -8.40 am. 9.30 -11.30 am. 31.600 W3XKA PHILADELPHIA, PA., 9.494 m., 17.760 DJE BERLIN, GERMANY, 16.89 m., 15.210 Addr. NBC. Relays KYW 9 am.- W8XK PITTSBURGH, PA., 19.72 m., Addr. Addr. Broadcasting House. 12.05- 10 pm. (See 21.540 mc.) 8 am. -6 pm. 10 am.; also Sun. 11.10 am -12.25 15.200 DJB BERLIN, 31.600 W5XAU OKLAHOMA CITY, 9.494 m., Sun pm. Daily 4.50 -10.45 pm. GERMANY, 19.74 m., 12 n-I pm., 6 -7 Addr. (See 15.280 mc.) 12.05 -II pm. Irregular 17.760 W2XE NEW YORK, 16.89 other times. N. Y., m., Addr. am., 4.50 -10.45 pm. Also Sun. Col. Broad. System, 485 Madison 11.10 am.-I2.25 pm. 31.600 W4XCA MEMPHIS, TENN., 9.494 m. Addr. Ave. Irregular. Memphis Commercial 15.190 - ROME, ITALY. 19.75 m. Relays 2R0 Appeal. 17.755 ZBW5 HONGKONG, CHINA, 16.9 m., Relays WMC. till 6 pm., irreg. Addr. P.O. Box 200. 4 -10 em. 15.190 31.60) W8XAI ROCHESTER, - LAHTI, FINLAND. 19.75 m. Addr, N. Y., 9.494 m., Addr. Irregular. (See OFE, 9.5 mc.) Irregular. Stromberg Carlson Co. Relays WHAM 7.30 -12.05 am. End of Broadcast Band 15.190 ZBW4 HONGKONG, CHINA, 19.75 m., Addr. P. 0. Box 200. Irregular. 31.600 W8XWJ DETROIT, MICH., 9.494 m., Addr. 17.310 W2XGB HICKSVILLE, L. I., N. Y., 17.33 m., 11.30 pm. to 1.15 am., 3 -10 am. Evening News Ass'n. Relays WWJ Addr. Press Wireless, Box 296. 6 -12.30 am., Sun. 8 am 12 m. Tests 9.30.11.30 am. except Sat. 15.180 RW96 MOSCOW, U.S.S.R., 19.76 m. Mon., Tues., Fri., Sat. 2.30.3.30 31.600 W9XPD ST. LOUIS, MO., 9.494 m., Addr. and Sun. pm. Daily 3 -4 am. Mon., Wed.. Pulitzer Pub. Co. Relays KSD. 15.550 CO9XX TUINICU, ORIENTE, CUBA, 19.29 Thurs. 7 -9.15 pm. 26.450 W9XA KANSAS CITY, MO., 11.33 m., m., Addr. Frank Jones, Central 15.180 GSO DAVENTRY, ENG., 19.76 m., Addr. Addr. Commercial Radio Eqpt. Tuinicu, Tuinicu, Santa Clara. Co. Testing Broadcasts irregularly evenings. (See 17.79 mc.) 4.15 -6, 6.20 -8.30 pm., 3 -5.15 am., 9 am. -12 n. 26.400 W9XAZ MILWAUKEE, WIS., 11.36 m 15.510 XOZ CHENGTU, CHINA, 19.34 m. Daily 15.170 TGWA GUATEMALA CITY, GUAT., 19.77 Addr. The Journal Relays 9.45.10.30 am. Co. Addr. (See 17.8 mc.) Daily WTMJ from I pm. 15.370 HASS BUDAPEST, HUNGARY, 19.52 m., 10.45 -11 am.; Sun. 10.45 am. -6 26.300 W2XJI NEW YORK, N. Y., 11.4 m., Addr. Addr. Radiolabor, Gyali Ut 22. pm. Bamberger Broad. Service, 1440 Sun. 9 -10 am. 15.160 XEWW MEXICO CITY, MEXICO, 19.79 m., Broadway. Relays WOR 8 -I 15.360 am. DZG ZEESEN, GERMANY, 19.53 ro.., 12 n. -12 ro., irregular. am. Irregular. Addr. Reichspostzenstralamt. Tests 26.100 W9XJL irregularly. 15.160 JZK TOKYO, JAPAN, 19.79 m. Irreg- SUPERIOR, WIS., 11.49 m. Relays ular. WEBC daily. 15.360 - BERNE, SWITZERLAND. 19.53 m. 15.160 VUD3 DELHI, INDIA, 19.79 m., Add All 26.050 W9XTC MINNEAPOLIS, MINN., 11.51 m. Irreg. 6.45.7.45 pm. India Radio. 1.30 -3.30 am., 8.30- Relays WCTN 9 I 7 pm.- am: pm., 10.30 pm. 12 m. 15.155 SMSSX STOCKHOLM, SWEDEN, 19.79 m., 25.950 W6XKG LOS ANGELES, CAL., 11.56 m., /9 /Kat. iltoadcaet iland Daily II am. -5 pm., Sun. 9 Addr. B. S. McGlashan, Wash. am: 15,340 5 pm. Blvd. at Oak St. Relays KGFJ DJR BERLIN, GERMANY, 19.56 24 hours daily. Addr. Br'dcast'g House, 8 -9 am.. 15.150 YDC BANDOENG, JAVA, 19.8 m., Addr, 4.50-10.45 pm. N. I. R. O. M. 6 -7.30 pm., 10.30 25.950 W9XUP ST. PAUL MINNESOTA. 11.56 m. pm. -2 am., Sat. 7.30 pm.-2 Relays ItSTP evenings. 15.330 W2XAD SCHENECTADY, N. Y., 19.56 m., am., Addr. General Electric Co. Re- daily 5.30 -10.30 am. 21.550 GST DAVENTRY, ENG., 13.92 m., Addr. lays WGY, 12.15 -6 pm. 15.140 GSF DAVENTRY, ENG., 19.82 m., (B.B.C., London) Irregular at Addr. present. 15.320 OLRSB PRAGUE, CZECHOSLOVAKIA. (See 17.79 mc.) 3 -5.15 am., 5.45 19.58 m. Addr. (See 11.840 mc.) am. -12 n. 21.540 W8XK PITTSBURGH, PA. 13.93 m., Addr. Sun., Wed., Sat. 5 -5.10 pm.. 15.130 TPB6 PARIS, FRANCE. 19.83 m., Addr. Gra ^t Bldg. Relays KDKA 6.45 -9 Mon., Tues., Thurs., Fri. 6.55.9.55 "Paris Mondial," 98 Bis Blvd. am. Also Sunday. 6 pm. pm. Haussmann, 2 -5 am. 21.530 GSJ DAVENTRY, 13.93 ENG., Add. 15.310 GSP DAVENTRY, ENG., 19.6 m., Addr. 15.130 WIXAL BOSTON MASS., (See 21.550 mc.) 19.83 m., Addr, 5.45 -10.30 am. (See 17.79 mc.) 3 -5.15 am., 1.45 -4 World -Wide B'casfg Founda- 21.520 W2XE NEW YORK CITY, 13.94 m., Addr. Pm. tion. University Club. 10 -II am., Col. Broad. Syst.. 485 Madison 15.300 YDB SOERABAJA, JAVA, N. E. I. 19.61 Mon. -Fri. Ave. Daily exc. Sat. Sun. and Addr. NIROM. 7.30 pm. -2 am. 15.120 HVJ VATICAN CITY, 19.83 m., 10.30- 7.30 -10 am. Sat. and Sun. 8 am: 15.300 XEBM MAZATLAN, SIN., MEX., 19.61 m. 10.45 am., Tues., Wed. 6 Thurs. I pm. Addr. Box 78, "El Pregonero del 15.110 DJL BERLIN, GERMANY, 19.85 m., 21.500 W2XAD SCHENECTADY, 13.95 m., Pacifico." Irregularly 9 -10 am., N. Y., Addr. (See 15.280 mc.) 12 m. -2, 1 -2, 8 -10 pm. General Electric Co., 8 am. -12 n, 8.9 am., 10.40 am. -4.25 pm., also 21.470 GSH DAVENTRY, ENG., 13.97 m. (See 15.300 - ROME, ITALY. 19.61 m., Addr. (See Sun. 6 -8 am. 21.550 roc.), -12 2R0, 11.81 mc.) Relays to 6 5.45 am. n. 2RO 15.080 RKI MOSCOW, 19.87 pm. irregularly. U.S.S.R., m. 21.450 DJS BERLIN, GERMANY, 13.99 m Works Tashkent near 7 am. Broad- Addr., Broadcasting House. 12.05 - 15.290 LRU BUENOS AIRES, ARG., 19.62 m. casts Sun. 12.15 -2.30 pm. Daily am. Addr. El Mu^do. Relays LRI, 7 -9.15 pm. 19.020 HS8PJ BANGKOK, SIAM, 15.77 m. Mo-- 7 -9 am. End of Broadcast Band days 8 -10 am. 15.280 H13X CIUDAD TRUJILLO, D. R., 19.63 rn. Relays HIX Sun. 7.40.10.40 am. 14.940 PSE P.1O DE JANEIRO, BRAZIL. 20.08 18.480 HBH GENEVA, SWITZERLAND, 16.23 m., Weekdays 12.10 -I.10 pm. Broadcasts Wed. 3.45 -4.15 Addr. Radio Nations. Sun., 10.45 - pm. 30 e -. 15.280 DJQ BERLIN, GERMANY, 19.63 m., Addr. Broadcasting House. 12.05- 14.600 JVH NAZAKI, JAPAN, 20.55 m. Broad- 10 am., 4.50 -10.45 pm. Also Sun. casts irregularly 5 -11.30 pm. /6 Met. ßtoadcait Band 11.10 am -12.25 pm. Works Europe 4 -8 am. 15.270 W2XE NEW YORK CITY, 19.65 m., Addr. 14.535 HBJ GENEVA, SWITZERLAND, 20.64 m., 17.820 - ROME, ITALY. 16.84 m., Addr. (See (See 21.520 mc.) Daily extent Addr. Radio Nations. Broadcasts 11.81 Sun. 1.45 -2.30 pm., Mon. 7 -8.30 2R0. mc.) Relays 2R0 to Sat. and Sun. 1 -6 pm., Sat. 3^d 6 pm. irregularly. Sun. 2.306 pm, Pm. (Continued on page 476)

All Schedules Eastern Standard Time

474 RADIO & TELEVISION

www.americanradiohistory.com OSO N''/ To Kedoo //Y 1f/ßá On 41 K Cs Sin has been W«e` VI/ GMT On 1 rbC/eY a l'r sip. OHO \\S \ ß°T40 OKN f ,f ss S OR.M ude 1320 r. 05B TANANARIVE t> With rFB'C E Born K L . r BEGINNING a new period of service on Here's to DX : ORA this page after a brief surcease, we look PAPUA '411i F Paul BOUK forward to your cooperation, as in the past. l'anenerive VHPNI, 8.08 Inc., Port Moresby. has been 41111, Reports on DX heard, amateur 'phone. MADAGASCAR heard several times, once at 6:25 a.m., and [X = //eCountrie Xlr = C.C. SWBC, and commercial 'phone are equally much earlier, at 4:05 a.m. This is a new Final sav. f/, welcomed, and should be mailed to reach Tr.Luft' Klx = country for all fixers, and can be heard if us at RADIO & TELEVISION, 99 Hudson St.. e t!'L dr OB O.L!1 one tries around 5:30 -6:30 a.m. when it is 73 en velr,llln New York City, not later than 5th of each usually on. This station has been used only T.`o month. for telephony, as far as we know. Reports can he sent to VHP\I. Port Moresby. THE MALAYAN AMATEUR i The Sc.,, hue pl..,.,'r`' FB8AB- Madagascar. be well heard Here's the prize QSL for RADIO SOCIETY. .chnpwledg.,o are a, dared Papua. The signal should ;Ó/-r/ our 10 meter harmonics reception of O M Irr..n.Aw+.. ..c 1/. Altt.c? now in the cool weather. so try to add this .hrnu,h Paul's 20 meter signals. Blue letters, ANNA. FB new country to your log! red map STATION ZOE. und ponfinn ,ha, a..,,lroan rx outline. Voy e.v,..,r u r. g T. D.p....Ig. in the w.h ,r ',SLIMS Another station at Port \loresby, \'IG, 411.90 to (6135 Rr:.l on 7.31 mc., has been reported rebroadcast- lag fwG °.73.,(7Cro3Y- «, fr. r13.0-9p.m ing a local BC station's programs. usually (11w ' GMT./ the hour. Then an announcement in perfect i in 1st 3rd Sats. of each month, from and English. mentioning call as VUD3. 3 -5 a.m., though this is not a regular sched- TUESDAY, FRIDAY & SUNDAY, Knafa A. p,.. Here's an Asiatic you can all hear, as we ule. probably more of a test broadcast, occa- (excluding Holidan) get it swell when using a 3 tube regenerative .red p,5/n4,e. sionally. set ! It really does pound in! welcome rrpnn.. 3. l ...... ,03). ANGOLA You probably feel as we do, regarding CR6AA, 13.00 mc., at Lobito. is now the mass of schedules and frequencies pub- heard regularly on this new frequency, be- lished on the new National Xmtrs in India, and it is a bother f M M -e1 rOt tR /%'i' 3-E sides its old 7.177 nu. wave. Evidently the going through all that, 9 mc. freq. is to be used only occasionally. when one feels he can't hear 'em anyway! as conditions warrant. But here's one we will vouch for ! Schedule This new frequency should be well heard is front 8:30 -10:30 p.m. daily, best signal this winter. much easier to log than that at 8:30, and gradually weakening towards 7 mc. sig.. right in the thick of the 40 meter 10 :30. band's hash. Veris have been hard to elicit from the The schedule remains the same. Wed. and Indian broadcasters, for some reason, but Sat.-2 :45-4 :30 p.m. we have a QRA which should be OK, being This station QSL's all reports with a taken front a veri. Here'tis: Lieut. N. A. S. handsome card. shown here some time ago. Lakshamanan, Station Director, All India It is well worth having, being a "hard -to- Radio, Delhi, India. This, of course. for get" country for all Dxers. Delhi transmitters. VUD2, on 9.59 mc., should be well heard Two fine catches -ZGE and JFZC Send your reports to P. O. Box 103, Lobito, Angola, Port. \Vest Africa. when this comes out, as last year, so keep a watch out for this frequency, undoubtedly As our mag's title was recently altered, INDIA carrying same program. Best "sig," as on VAC certificates had to be withdrawn till VUD3, 15.16 mc., at Delhi, is putting a VUD3. is at 8:30 p.m. VUD2 is at Delhi, new plates, with new title, were made, so beautiful R8 signal into New York right too. kindly be patient, OM's -the certificates are now, and should continue doing so for a We could give you the whole mess of being mailed. long time to come. You can't miss it, all station schedules, etc., but we prefer telling clear by itself on you what you can actually hear, and be 15.16 mc.. just to able to "log." Do you agree with our policy? low freq. side of \ - \ -N, at Madras, on 13.35 inc., using inverted QSO te/-. / tqf England's GSO. speech, very strong at 4 a.m., with st.uen XJ J L ., ete en! usual Asiatic "flutter" noticeable on signal. reçue -phonie A carrier can be //344T.M (ì. Jack Buitekant. Bronx, is to be congratu- Notre Émetteur: Vets Reception: heard just before schedule. 8:30 p.m. lated on landing and getting verified, Trpe:A.E NY AC. RAC. DC. Phone V \VY1 at Poona. India. Nice going, OM, Lampes:2 T: Modul.: and at 8:30 sharp. f410 you'll hear chimes for a beginner! HT: 32,01 Volts QSA: ' QRK Rj Input: 32... tiO F QRG:..ÿhL and bells striking INDO -CHINA Ant.: FZS. 18.388 mc., at Saigon, was logged Modul. QRA: QRO: Qsy t again. at 7:03 a.m. the other day, in QSO Le prix d'a,fc! (kilte lampe ne signifie t, g/to with FTM. 19.355 mc., St. Assise, France. Notre temple.: rien sil'o kmAlle pas compte de sa dr(ei. P.Q_6.If° FTM had called at 6:00 a.m. but no reply e vie.tU from Saigon ; this in clear speech. FTM horaire des PHILIPS ) sends a musical signal consisting of 3 to 4 RS roeerevlent FY8AC- French Ob notes (tones) repeated over and over. At y,y' t a Guiana. A plain 7 a.m. these tones ceased, and we knew due.4.) eti Caa9-1. 0. 1 .QS white card with red FTM would again call. We heard -"allo DX i 1á Sts Ion: . .e 00, asL. Ox. 5n lettering, but it's still Saigon, ici Paree," and, turning to FZS'

a nice veri, hi! (Continued on page 489)

for December. 1938 475

www.americanradiohistory.com Mc. Call Mc. Call Mc. Call 14.440 - RADIO MALAGA, SPAIN, 20.78 m. 11.801 DJZ BERLIN, GERMANY, 25.42 m. 7.15- 10.535 JIB TAIHOKU, TAIWAN, 28.48 m. Relays Salamanca 8.15 -8.45 pm. 10.50 pm. Works Japan around 6.25 am. Sometimes 2 -4 pm. 11.800 JZJ TOKYO, JAPAN, 25.42 m., Addr. Eroadcasts, relaying JFAK 9.05.10 am., 1 -2.30 am. Sun, to 10.15 am. 14.420 HCJB QUITO, ECUADOR, 20.8 m. Dai . Broadcasting Co. of Japan, exc. Mon. 10-11 pm. Overseas Division. 7 -7.30, 8 -9.30 10.370 EAJ43 TENERIFFE, CANARY ISLANDS, 14.166 PIIJ DORDRECHT, HOLLAND 21.15 m., am., 2.304, 4.30 -5.30, 8 -8.30 pm., 2.0.93 m. Keiays Salamanca, 12.30 Addr. (See 7.088 mc.) fat. 12 n.. -1.30 am. Spain, 2 -4, 5 -9.45 pm. 12.30 pm. 11.795 DJO BERLIN, GERMANY, 25.43 m., 10.350 LSX BUENOS AIRES, ARG., 28.98 m., 14.004 EA9AH TETUAN, SPANISH MOROCCO, Addr. (See 15.280 roc.) hddr. Transradio International. 21.4 m. Apartado 124. News at 11.790 WIXAL BOSTON, MASS., 25.45 m., Addr. Tests irregularly, 4.30 and 7.15 pm. Relays Sala- (See 15.250 mc.) Daily 4.55 -6.30 10.330 ORK RUYSSELEDE, BELGIUM, 29.04 m. manca from 5.40 pm. pm., Tues., Thur., 4.40.6.30 pm., broadcasts 1.30 -3 pm. Works 13.635 SPW WARSAW, POLAND, 22 m. Daily Sat. 1.45 -6 pm., Sun. 5 -6.30 pm. OPM 1 -3 am., 3 -5 pm. 6 -8 pm. Sat. & Sun. 6.9 pm. 11.780 HP5G PANAMA CITY, PAN., 25.47 m 10.290 DZC ZEESEN, GERMANY, 29.16 m., 12.460 HCJB QUITO, ECUADOR, 24.08 m. Daily Addr. Box 1121. Heard till 12 rr. Addr. (See 15.360 mc.) Irregular. exc. Mon, 10 -11 pm. 11.780 OFD LAHTI, FINLAND. 25.47 m. Addr. 10.260 PMN BANDOENG, JAVA, 29.24 m. Re- 12.862 W9XDH ELGIN, ILL., 23.32 m. Press Wire. (See OFE, 9.5 mc.) 1.05 am: ays YDB 6 -7.30 pm., 10.30 pm.- less, Tests 2 -5 pm. 2.05 pm. _' am., 4.30 -10.30 or II am., Sat. -0 11.30 am, 12.235 TFJ REYKJAVIK, ICELAND, 24.52 m. 11.770 DJD BERLIN, .GERMANY, 25.49 m., Works Europe mornings. Broad- Addr. (See 15.280 mc.) 10.40 am.- 10.220 PSH RIO DE JANEIRO, BRAZIL, 29.35 casts Sun. 1.40 -2.30 pm. 4.30 pm., 4.50 -1I pro. Addr. Box 709. Broadcasts 5.9 pm. 12.200 TRUJILLO, PERU, 24.58 m., "Rancho 11.760 TGWA GUATEMALA CITY, GUAI., 25.51 - m. (See 17.8 mc.) Irregular 10- 10.042 DZB ZEESEN, GERMANY, 29.87 m., Grande." Address Hacienda Chiclin. Irregular. 11.30 pm. Sun. 6 -11.30 pm., ir- Addr. Reichspostzenstralamt. Ir- regular. egular. 12.060 RNE MOSCOW, U.S.S.R., 24.88 m. Daily 11.760 9.980 6 -7 am., 12 n. -2 pm. 3 -6, 10.15 -1I XETA MONTEREY, MEX. 25.51 m., Addr. COBC HAVANA, CUBA, 30.04 m., Addr. pm., also Tues., Thurs. 8.30-9 Box 203. Relays XET, 13.30 pro. O. Box 132. Relays CMBC p-n., also Sun. 6.10.30 am., 12 n and evenings. 5.55 am..12 m. 5 pm., 6 -6.30, 8.30 -9, 10.15.11 pm. 11.760 OLR4B PRAGUE, CZECHOSLOVAKIA, 9.940 JDY DAIREN, MANCHUKUO, 30.18 m. 11.970 HI2X CIUDAD TRUJILLO, D. R., 25.07 25.51 m., Addr, (See 11.840 mc.) Relays JQAK daily 7 -8 am. Works m., Addr. La Voz de Hispaniola. Irregular. Tokyo occasionally in early am. Relays HIX Tue. and Fri. 8.10- 11.750 GSD DAVENTRY, ENG., 25.53 m., Addr. 9.860 EAQ MADRID, SPAIN, 30.43 m., Addr. 10.10 pm. B.B.C., London, 3.5.15 am., 10.45 Post Office Box 951. 7.30 -8, 8.40- am. -6.07 pm., 6.20 -8.30, 9.20 -11.25 9 pm. pm. 9.833 COCM HAVANA CUBA. 30.51 m. Addr. 11.740 COCX HAVANA, CUBA. 25.55 m. P. 0. Transradio Columbia, P. 0. Box 25 /flet. iltoacicast ilancl Box 32. Daily 8 am.-1 am. Su ^. 33. 8 -1 am, Relays CMCM. 8 am. -12 m. Relays CMX, 9.830 IRF ROME, ITALY, m. Works 11.920 TI2XD SAN JOSE, COSTA RICA. 25.19 m. 30.52 11.740 HVJ La Voz del Pilot. Apartado 1729. VATICAN CITY, 25.55 m. Testing Egypt afternoons. Relays 2RO, regular, 5 -9 pm. II am. -2 pm., 5 -1I pm., exc. Su-. 11.730 PHI HUIZEN, 9.760 SAIGON, INDO- 30.72 m., 11.910 CDI190 VALDIVA, CHILE, 25.2 m., P. 0. HOLLAND, 25.57 m.. CHINA, Addr. N. V. Philips' Addr. 17, Place A. Foray. "Radio Box 642. Relays CB69 10 am. -1 Radio. Dail, pm., II am. -I0 pm. 6.15.6.45 pm. Sat. 7.15.7.45 pm. Boy -Landry." Heard 6 -9.15 am. 11.730 WIXAL BOSTON, MASS., 9.740 COCA HAVANA, CUBA, 30.85 m. 11.900 HANOI, FRENCH INDO- 25.57 m., Addr. Addr. - CHINA. World Wide B'cast'g Founda- 25 No. 445, Vedado, Havana, 25.21 m. "Radio Hanoi ", Addr. tion, University Club. Daily exc. 7 -1 am. Sun. 6.55 am.-I2.30 pm. Radio Club de l'Indochine. 12 ro.- Sat, and Sun. 9 -11 pm. 2 am., 6 -10 am. 9.710 CSW5 LISBON, PORTUGAL. 30.87 m. 11.720 CJRX WINNIPEG, CANADA, 25.6 m., Addr, Nat. Broad. Sta. 5.8 pm. 11.900 XEWI MEXICO CITY, MEXICO, 25.21 m., Addr. James Richardson & So-s Addr. P. 0. Box 2874. Mon., 9.700 FORT DE FRANCE, MARTINIQUE, Ltd, Daily 6 pm. -12 m., Sun. 5- - Wed., Fri. 3 -4 pm., 9 pm.-I2 m. 30.9 m., Addr. P. 0. Box 136. 10 pm. Tues. and Thur. 7.30 pm. -12 m., 11.30 am. -12.30 pm., 6.15 -7.50 pm. 11.718 CR7BH Sat. 9 pm. 12 m. LAURENCO MARQUES, PORTU- 9.690 TI4NRH HEREDIA, COSTA RICA, 30.94 m., GUESE E. AFRICA, 25.6 m, Daily 11.895 HP5G PANAMA CITY, PAN-, 25.22 m., Addr. Amando C. Marin, Apar- 12.05.1, 4.30 -6.30, 9.30 am.. Addr. Box 1121. 9.30 am.-1 pm., -II tado 40. San. 7 -8 am. Tues., 12.05 -4 pm., Sun, 5.7 am., 10 am.- 6 -11 pm. Thurs., Sat. 9 -10 pm. 2 pm, 11.885 TPA3 PARIS, FRANCE, 25.24 m., 9.685 TGWA GUATEMALA CITY, GUAT., 30.96 Addr. 11.715 TPA4 PARIS, FRANCE, 25.61 m., (See (See 15.245 roc.) 2 -5 am., 11.15 m. Daily 10 -11.30 pm.: Sun. 6- 15.245 roc.) 7 -9.15 9.30 am. -6 pro pm., pm.- 11.30 pm. 12 m. 11.885 TPB7 PARIS, FRANCE, 25.24 m. (See 9.680 ZHP SINGAPORE, MALAYA. 30.98 m. 11.710 SBP MOTALA, SWEDEN, 25.63 m., 1.20 15.245 mc.) 7 -9.15, 9.30 pm. -12 m. Sun. 5.40 -9.40 am., Wed. 12.40- 2.05, 6.9 am., II am. -I pm., Sat. 11.870 W8XK PITTSBURGH, PA., 25.26 m., Addr. 1.40 am., Mon. -Fri. 4.40 -9.40 am., I.20 -2 a.m., 6 am. -1.30 pm., Sur (See 21.540 roc.) 6 -8.45 pm. Sat. 12.25 -1.40 am., 4.40 -9.40 am., 3 am. -I.30 pm. Wed. and Sat. 10.40 pm.-I.10 am. (Sun.). 11.865 BERNE, SWITZERLAND. 25.28 m. 8 -9 pm. - ..673 DZA ZEESEN, GERMANY, 31.01 m., Irreg. 8.9 pm, 11.710 YSM SAN SALVADOR, EL SALVADOR, Addr. (See 10.042 mc.) Irregular. 11.860 GSE DAVENTRY, ENG., 25.29 ro., Addr. 25.63 m., Addr, (See 7.894 Inc., 2670 ROME, ITALY. (See 11.75 roc.) 3 -5.15, 5.45 am: Irregular 1.30 -2.30 cm. - 31.03 m. Relays 2R0 11.710 - SAIGON, FRENCH INDO -CHINA 6 -9 p.m. Irregular. 11.855 DJP BERLIN, GERMANY, 25.31 m., 25.63 m., Addr. Boy- Landry, 17 W3XAL BOUND BROOK, N. J., 31.03 m. Addr. (See 15.280 mc.) Irregular Place A Foray. 6.9.15 am. Addr. NBC, N. Y. C. 5 pm. -I2 m. 9.660 LRX B'JENOS 11.35 am. -4 pm. 11.700 HPSA PANAMA CITY, PAN., 25.65 m AIRES, ARG., 31.06 m., Addr. El Mundo. Relays LRI, 11.840 KZRM MANILA, P. Addr. Radio Teatro, Apartado I., 25.35 m. Addr. 9.30 am. -II pm. Erlanger & Gallinger, Box 283. 954. 10 am. -i0 pm. 9 pm.-I0 am. Irregular. 11.700 CBI170 SANTIAGO, CHILE, 25.65 m, Add, 9.650 CS2WA LSBON, PORTUGAL, 31.09 m., Addr. Radio 11.840 CSW LISBON, PORT., 25.35 m. Nat'l P.O. Box 706. Relays CB89 t Colonial. Tues., pm. -12 m. Thurs. and Sat. 3.30 -6 pm. Broad. Station. 1 1.30 am. -I.30 pm. Irregular. End of Broadcast Band 9.645 HH3W PORT -AU- PRINCE, HAITI, 31.1 ro., Addr. P. 0, Box A117. 1 -2, 7.8 1 1.840 OLR4A PRAGUE, CZECHOSLOVAKIA, 25.34 11.676 IQY ROME, ITALY. pro. m., Addr. Czech Shortwave Sta., 25.7 m. Relays 2R0 1.35 -2.25, 6 -9 pm. Praha XII, Fochova 16. 9.640 CXA8 COLONIA, URUGUAY, 31.12 m., Daily 11.530 SPD WARSAW, 12.55 -4.30 pm, Mon., Tues., Thurs., POLAND, 26 m., Addr. Addr. Belgrano 1841, Buenos 5 Mazowiecka St. 6-9 Fri. 7.55 -10.55 pm., Sun. 5.55 -8.55 pm. Aires, Argentina. Relays LR3, pm. 11.402 HBO GENEVA, SWITZERLAND, 26.31 m.. Buenos Aires 6 am. -I0 pm. Addr. Radio Nations. 11.830 W9XAA CHICAGO, ILL., 25.36 m., Addr. Sun, 7.7.45 9.635 2R0 ROME, ITALY, 31.13 m., Addr. pm., Mon. 1 -1.15 Chicago Federation of Labor. am., 7 -8.30 pm. (See 11.810 mc.) 12.05 -9 pm. 11.040 CSW7 Irregular 7 am. -6 pm. LISBON, PORTUGAL, 27.17 m 9.630 HJ7ABD BUCARAMANGA, COL., 31.14 m. Addr. Nat. Broad. 11.830 W2XE NEW YORK CITY, 25.36 m., Addr. Sta. 1.30 -5 pm. 10 am. -12 n., 4 -11 pm. 11.000 PLP Col. Broad, System, 485 Madison BANDOENG, JAVA, 27.27 rn. Re- 9.625 JFO TAIHOKU, TAIWAN, 31.16 m. Re- lays YDB. Av.. N.Y.C. 6.30 -11 pm. 6 -7.30 pm., 10.30 pm.. lays JFAK irreg. 4 -10 am. 2 am., 4.30 -10.30 11.826 XEBR HERMOSILLA, SON., MEX., 25.37 or II am. Sat. 9.616 11.30 HJIABP CARTAGENA, COL., 31.20 m., Addr. Box 68. Relays until em. XEBH. Addr. P. Box 37. I I I 10.960 0. am: pm., 1 -9 pm., 9 pm. -12 TAN ANAR IVE, MADAGASCAR, ro. - 5.11 pm., Sun. 10 am.-1 pm., 3- 27.36 m., 11.820 GSN DAVENTRY, ENG., 25.38 m., Add'. Addr. (See 9.38 roc.) 6 pm. 12.30 -45, (See 11.75 Inc.) Irregular. 3.30 -4.30, 10 -11 am. Sun. 9.615 ZRK KLIPHEUVAL, 2.30 -4 am. SOUTH AFRICA, 11.810 31.2 m., Addr. P. Box 4559, 2R0 ROME, ITALY, 25.4 m., Addr. 10.670 CEC 0. SANTIAGO, CHILE, 28.12 ro. Johannesburg. Daily, exc. Sat. E.I.A.R , Via Montello 5. Daily Irregular. 11,45 4.40845 am., 10 am. -9 pm. pm. -12.50 am. Daily exc. 10.660 JVN NAZAKI, JAPAN, 28.14 m. Broad- Sun. 3.20 -7.20, 9 -11.45 am., Sun. 11.805 COGF MATANZAS, CUBA, 25.41 m., casts daily 2 -8 am. Works Europe 3.30 -4.30 or 4.5, 5.30 -7, 9 -11.45 Addr. Gen. Betancourt 51. Re- irregularly at other times. am. lays CMGF. 2 -3, 4.5, 6 -11 pm. 10.600 ZIK2 BELIZE. BRIT. HONDURAS, 28.25 9.607 HP5J PANAMA CITY, PANAMA, 31.23 11.805 OZG SKAMLEBOAEK, DENMARK, 25.41 ., Tue., Thurs., Sat. 1.30-2, 8.30- m Addr. Apartado 867. 12 n. to m. Addr. Statsradiofonien. Irreg. 9 pm. 1.30 o ., 6 -10.30 em. r('on'inurd on page 501)

All Schedules Eastern Standard Time

476 RADIO & TELEVISION

www.americanradiohistory.com Radio Kinks Each month the Editor will award a 2 year subscription for the hest kink submitted. All other kinks published will he awarded eight months' subscription to RADIO & TELEVISION. Look over these kinks: they will give you some idea of what is wanted. Send a typewritten or ink description with sketch, of your favorite to the Kink Editor.

1 -CUT DIAPHRAGM FROM Co -Axial Lead -in Flexible Coupling CARDBOARD 2'I6 DIA. (WACEDCARD BOARD Here is a FB insulated and DREREORED) To make this neat lead -in First Prize flexible condenser panel, cut a piece of bakelite, ply- extension 3- POINTED ENOS of a OF TIN PIECE wood, or other suitable material shaft ; the shaft consists FORCED Auto Transformer piece of glass tubing, which can THROUGH to fit in the window sill, so that be made any desirable length, 2 -CUT PIECE CARDBOARD the window, when partly open, A single winding auto trans- of TN I %4' LONG will rest on the top edge of the former is a handy thing for fitting into a rubber coupler INSERTED which in turn fits onto the con- IN CENTER panel, which may be weather - securing a variety of filament OF CARO- , voltages when used in conjunc- denser shaft. By using this ar- BOARD stripped to provide a tight tit. Holes are drilled to tion with a filament transformer rangement, a costly extension is then ac- not needed when one uses an commodate insulated banana or having but one low- voltage BEND OVER winding. The auto transformer inclined panel, as this coupler ENOS OF POINTED G R jacks; jack feed -thru in- TIN PIECE may may consist of 150 turns of No. will operate satisfactorily at sulators be used also. A 24 D.C.C. wire, wound on the angles up to 60 degrees. -R. H. lightning arrester, antenna cou- core of an old audio transformer. Alexander. PI pler, and changeover switch, to Home -Made connect the aerial to either the It should be tapped at the 50th Diaphragm and the 100th turn. When con- receiver or transmitter, may also 11NCH RUBBER. VARIABLE Sometimes the diaphragm of a be it deliver TURING mounted on the board. - nected as shown, will CONDENSER headset becomes bent or other- Charles E. Baker, Jr. either 5 or 7% volts from a wise damaged, in which case it transformer having a 2% volt is practically impossible to re- secondary. Other taps on the pair, and a new one must be \ auto transformer will deliver c ANT LEAD -IN purchased. This often necessi- any desired voltage. I f the tates considerable delay, during 3/8 luto transformer heats up un- GLASS which time the phone is un- SOFT duly, it would be advisable to TUBING COPPER usable. TUBING use a heavier gauge wire than WILL WORK Not wishing to wait while a No. 24.-Eugene Crow. SATISFACTORILY RUBBER INSULATION OP TO 60° ANGLE STAND- new diaphragm was shipped OFF INSULATOR. from the factory, I cut a diaphragm from the waxed paste- board in an old empty fruit jar, and fitted it with an armature N2.14 COPPER WIRE Beeps Pencil Ready cut from an old tin can -the Every Ham knows that the pointed ends of the tin being hardest piece of equipment to pressed through the cardboard keep is a common, ordinary lead and clamped on the back. The Automatic Code Sender pencil. The pencil is always results were so good that I put A novel, inexpensive, auto- missing just when needed most a cardboard diaphragm in the matic code sender for the Ham DRILL A SHALLOW to copy some real DX signals other phone, too. I found that using ICW, or code practice aid HOLE IN CHASSIS the tone was better, ami there FOR CONNECTION and I therefore hit upon this for prospective Hams, may be SOLDERING IRON scheme to keep a pencil on the was apparently less noise.- had by anyone possessing a E desk at all times. All you do is Ernest Palencia. (ED. NOTE : phonograph and suitable ampli- CHASSIS drill a %" hole up under the It may be necessary to add a fier. Merely feed the output of desk, put a string through, tie washer to keep the tin armature the amplifier through a 3 to 1 the pencil to one end and a from striking the phone's pole- transformer into pickup, and %ulderin;; to 1'leassiAl weight to the other. When you pieces.) that of an audio oscillator into want the pencil, reach under the input. A % lb. weight is attached Perhaps the sloppiest looking edge of the desk where the pen- Umbrella Antenna to the pickup to make a "home piece of work the average con- cil is hidden and pull it out -the A discarded umbrella from recording" needle cut. Records structor turns out is the "com- weight keeps the pencil in place. which the silk or cotton has been are of the "home recording" mon ground" on the chassis, -N. W. Slater. removed makes a highly effective type, available at most music usually just a large blob of antenna for a portable receiver stores.-Ed. Ramey. solder, irregular in shape and or transmitter. The ribs are left unpleasant in appearance. I have intact and are extended, as if in found a way in which to make use. This type of antenna has solder joints to the chassis both considerable area, and while the easily and neatly. Simply drill metal is not as highly conductive a shallow hole at the point where PENCIL as copper. it suffices very well the wire is to be connected to the for all practical purposes. If a chassis. This affords a well pol- DRILL V8'HOLE porcupine antenna is preferred. THROUGH SIDE ished surface to which the solder PANEL OF DESK the umbrella may he turned in- easily adheres. Molten solder is TOP FOR STRING STRING, side out. Incidentally, it does not LENGTH TO matter if one or two of the ribs then run into the cup -shaped de- SUIT pression thus formed, and the are broken -so a broken um- joint is made in a moment. - WEIGHT brella can be used.-Mario La- John Metsler. Cognato. for December, 1938 477

www.americanradiohistory.com Build this 441 Line T.R.F. Television Receiver

TELEVISION HAS TECHNI LLY'SEEN DEVELOND TO HKN DEGREE. THIS ARTICLE PROVIDES IMF LATEST INFORMATION IT WILL EE SOME Part TIME TELEVIVON IS GREAT 2- Conclusion OPPORTUNITIES OR ETPERIMENTErEDRS AND TECHNICIANS

23 ANODE ANT. COIL ments would surely cause trouble due to aboo" in the construction of T.R.F. ultra 3.ODDV OANGEaoui 1! RF. these elements sagging and touching one short -wave receivers. Great care should be GAIN CONTRDLI another. exercised to avoid them. In some cases, BAKELITE R CNCE RING SFt.NO ADlUETI Each R.F. stage is thoroughly shielded, where oscillation of one or more of the R.F. MENT REDWREOJI FELT preferably in copper or brass. Aluminum stages is encountered, "by- passing" the 2rA RE may be used, but because of the difficulty filament leads or inserting a small R.F. TUNING in soldering it, the shielding is not as effec- choke in series with each filament lead DIAL f 3R9 R F tive. will remedy the trouble. (See Fig. 1.) The circuits used differ from the usual Mica condensers are used throughout T.R.F. receiver only in that each stage is the R.F., detector and V.F. circuits for by- broadened out by "swamping" a fairly low passing. Where paper condensers are im- resistor across the tuned circuit, in order perative due to the large capacity required, HIGH to pass the unusually broad VOLTAGE frequency band these should be shunted with a mica con- fttiiitgitu rk, RECTIFIER previously mentioned. Great care must be denser no .005 mf. CAUTION smaller than The rea- taken in the physical "layout" of the com- son for is ev this procedure that at these very ponents so that every lead is as short as high frequencies, mica condensers have the possible. By way of mention, no wire need least inductance. Therefore, the high fre- be purchased for wiring the R.F. and V.F. quencies will be by- passed by the mica circuits other than the filament, ground and condensers and the paper condensers will B+ leads for the various tubes. The leads take care of the lower frequencies. The total gain of the receiver is governed by l_ 1 ' ------_.. the biasing resistor of 1500 ohms in addi- The finished chassis-ready for a cabinet and tion to the regular bias of 175 ohms in the a visual broadcast. cathode of the first R.F. stage. _T R.F.AMP. 1651 Detector IN the Nov. issue of this publication, a The detector is a diode of the 6H6 type, description was given of the cathode -ray similar to the detectors used in broadcast tube mounting together with the D.C. re- receivers, with the exception that only one storer circuit, the synchronizing separator, section is used in order not to load up the two power -supplies, and the vertical and circuit with too much "shunting" capacity. horizontal sweep circuits for a T.R.F. (tuned and thus lose some of the very high video radio frequency) 441 -line television re- frequencies. The plate resistor of this tube ceiver. is in series with a small choke which, with There follows a description of the tuned the reflected capacity of the succeeding tube, radio frequency circuits, the detector, the 359 RF.AMP 1651 "boosts" the response at the highest fre- video amplifiers and a suitable antenna sys- quency to be amplified and still keeps the tem for this receiver. phase change down to negligible propor- The reasons for choosing a T.R.F. receiver tions. This procedure is followed in the DIODE PET for television are obvious. GHG two succeeding video stages. (See Fig. 2 1. Simplicity of construction. and the schematic diagram.) 2. Broad frequency response (2,500.000 cycles side -bands must be passed for maximum detail of the transmitted image, ac- Side view of video s +ages. A flashlight cell cording to present day standards). J provices hum -free biasing. 3. Minimum number of tubes and asso- Side view of the R.F. stages. Note the careful C.R T GRID ciated apparatus. infersfage shielding. LEAD DEFLECTION 4. Freedom from complicated alignment 2Nó VIDEO procedures. of each resistor and condenser serve satis- STAGE -H- 5. Last, but not least, lower cost to the factorily for connectors, and in many in- constructor. stances these leads should be cut much shorter. Too much emphasis cannot be FILS B+ LEADS Three R.F. Stages stressed in using the very shortest leads The radio frequency section of this re- possible. ceiver consists of three stages of amplifica- 151 VIDEO Another very important factor to re- STAGE tion, using the special television amplifier member is to run all ground leads to one tubes designated as type 1851, which have a point in each shield, and then solder this 1 I/2 V. very high mutual conductance, namely 9000 point to a wire which runs down through FLASHLIGHT micronthos, as against 1200 to 1800 for a all the shields on each side and connects CELL similar tube used in short -wave and broad- only at one point on the chassis. In other cast receivers; yet the inter -electrode words, there will be one wire from each SYNCH. capacities are reasonably small. stage (R.F., detector, and v.F.) running to SEPARATOR Here is a word of caution on using the one point of the chassis somewhere in the LEAD 1851 tubes. Under no circumstances must lowest compartment of the assembly, and these tubes be used in a horizontal posi- there grounded to an actual ground. 1851 tion, as the close spacing between the ele- "Ground loops" are the greatest "bug-

478 RADIO & TELEVISION

www.americanradiohistory.com Adding the R.F. and 1851 1651 6Ftl' SPACED I 1 é*ENa±sr'RwrbR OF wiRE L

Video stages to the r 1E51 --L\ 1 Townsend Television -- \ /L^1 l / 100 I Receiver, thus com- ¡I (É>Cw) Ó..r.Si ( I C - k . Ç1' ( u` pleting the apparatus. `' 'LEG. _ r ` 1c: 0:, IF 1f,' 1 , a r Henry Townsend

F NIU. 6ON0 I pwMS ([) O60S Video Amplifier 05;1Ms NIú) aNMS r The video amplifier also uses two 1 2 5.1, . of the special television steep slope RFC. pentodes expressly for r--- r designed this 1D51 / purpose. This amplifier must pass 9$$ ' 05- W1 ,.01-N,F(MI[A_ C`. MCáoN --" _- p1R I (oáv(Ea) ' A' - frequencies from 30 cycles to 2.5 lLF^`_ip \ -'1 megacycles and amplify these fre- \MiCi..) ! ' ° f. LA.-- N`_ I JI---' : 1 , 7___sl quencies equally, with negligible l DMFp / /`, phase displacements. + 6w[[6 / ,.,Ig6 MF) (NiO>) ,w SvNCN6RON ING - , RESTORER M1 (Mppppçç %p M The data furnished with these >< ' } /eMF ! SERORñTOa éR R- -7 `iz- ñ íÿ--- tubes recommends that a cathode MlcàoN I Ci.ú U i ;,>.1ti I (.?...) ±T TI+ ,¢ l r pppp -- 150 j MIFiFo , resistor of at least ohms be OPnON,I egg- I 2 P 1p i CtgU.p- «Ai' used as bias. At radio frequencies, Tó+I 5 s CELL I IGOl c.4.7400._,____ this resistor can be by- passed with- lvv N cöc i é ñg (cv xovz COE4v OF S -OPTIONAL } out the least bit of degeneration or (NiiU) V y 2MF. L lg 7 eMF ëNET , sá.M S eVCeáf[N)S phase change, but when we en- Jw. counter this problem at a frequency - - T-.,CTU,L GRCLao i"r-J----J---- of 30 cycles, it would require a by- BENIN() ANTENNA pass condenser of at least 1000 REFLECTOR .S.,4 WAVELENGTN microfarads. Even at the low volt- II' \1 r 1L' ULATORS INSULATORS,.> age used, it would be quite a large \ .NSVLATCRS S'3" f 106- N condenser physically. and there- -- !O'6" I- fore, instead of the usual cathode [[ P ANO SLIOE FOR M,MM 21. -' 5%NAL STREING STGaTING ñT TTTTTT E BAR. 4f6p.p3 biasing, a small 1% -volt dry cell SNORriN4444 , 1 5'3" \ F,CEO MEGACYCLES", was chosen for the bias of these ` TRáNSñlíaTER FIG.3 iT by .01 mf. mica SN T i tubes, shunted a TO RECEIVER ggNGI \\/ condenser. This eliminated all problems of phase change and de- ?Ng q rT2UZgpas -cc" I generation at this frequency; and BAKELITE I in the end, it is more economical. ILO By studying the photographs ac- r= NFIG.IN +.FIG.2 fa::ÿaQ\Fï - F Lc companying this article, the reader Ó 4Ì IE 1¡=\\ will notice that the physical "lay- LEERRTÑENT T[,ó (v\\\` QO.- I ry55Er1 ES E E out" of the R.F., detector and the ^^[[r I TN E

for December, 1938 479

www.americanradiohistory.com 3 -Tube A.C. Receiver Range 16 to 550 Meters J. T. Wilcox, W2CLS

20.000 to 550 kilocycles. This includes the tered by means of a choke and condenser to broadcast band and all the important short prevent overloading or other trouble which wave ranges, broadcast, police, amateur, might develop if as. were allowed to reach aviation, marine, etc. All operating power the audio circuits. It is then resistance- is obtained from the 110 -120 volts a.c. light coupled to a 6F6 power -amplifier pentode, lines. with additiona: filtering An inexpensive all -band receiver for the SWL. to prevent hum, A 6K7 high -gain metal amplifier tube is this filter consisting of the 100,000 -ohm re- employed in a regenerative detector circuit sistor and .5 mf. condenser in the plate sup- as the first tube. The regenerative feature ply to the 6K7 tube. This audio tube is self - provides great sensitivity and is smoothly biased and the metal shells of both it and controlled by a potentiometer on the front the 6K7 are grounded to insure a high panel, by means of which the voltage ap- order of operating stability. plied to the screen grid is varied. The an- The loud speaker is an electro- dynamic tenna is capacity coupled to the grid of this type with a built -in transformer to match it tube, the condenser being one of the variable to the output impedance of the 6F6. Field - "trimmer" type, thus permitting the antenna coil excitation is obtained by connecting this coupling to be varied, and adapting the set coil in the B plus lead, where it serves as to use with any type of antenna. a filter choke with the 8 mf. condensers. The output of the 6K7 is thoroughly fil- (Continued on page 492)

Rear view of easy -to -build receiver.

i1 Wiring the 3 -tube receiver is dead easy when you follow this detailed picture diagram.

HERE is a simple 3 -tube receiver that offers a surprising number of good features yet is simple enough for the novice to build and effective enough in its operation on the air to command the interest of the more experienced constructor and shortwave listener. The receiver utilizes plug-in coils and provides continuous coverage of all ranges from 16 to 550 meters, or approximately Economical 25 Watt Xmitter Kit THIS tr.utsmitter as designed in an ni pliers. a soldering iron and a screw- livers 425 volts of well -filtered D.C. No effort to eliminate the headaches that driver. The power supply is mounted on a difficulties should be encountered in wiring confront the newcomer to amateur radio. similar chassis to the transmitter's and de- the outfit, and the placement of resistors It represents one of the simplest, efficient and condensers is left to the discretion of transmitters that a beginner can obtain in New 25 waft Xmitter, available in kit form. the constructor, who should attempt to its price bracket. keep the R.F. leads as short as possible. Arriving at a practical layout was not an Tuning the rig is simple: First, the easy ,matter. Many types of oscillators were crystal and the desired plate coil are placed built and tested in order to choose the one in their respective sockets and the power- from which the engineers could get the pack cable plugged into its receptacle on most for the least cost. The regenerative the rear of the chassis. A small neon tube, crystal oscillator was undoubtedly the best which is used as a resonance indicator in- oscillator from all angles. It was built with stead of a milliammeter for the sake of a minimum of parts and keyed stably with economy, should be placed on the stator no difficulty. Using a 6L6 tube, approxi- of the plate tuning condenser C -1. The plate mately twenty -five watts was obtained on and filament voltage should be switched on the fundamental frequency and good output and with the key closed, C -1 should be ro- was secured on the second harmonic, with tated until the neon tube reaches maximum this Eagle FB25 transmitter. With a 160 brilliancy. Now the antenna should be con- and 80 meter crystal, the four most popular nected and the antenna tuning condenser amateur channels are covered. The only C -2 rotated until a point is reached where tools necessary for construction are a pair (Continued on page 492)

480 RADIO & TELEVISION

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www.americanradiohistory.com r- i I- ENÓ 1 3'0R4 MASTER B+ UNIT

I I SPEAKERS RECEIVE OE DS 3701 ON BE f GANGED AI.JS, USED ic¢stioH ilox II

I SENO Single Tube Ham Transmitter

1 t I 1 I would like to construct a Horn transmitter using a single BATTERY 61.6 tube, with crystal control. I have a power unit delivering the necessary voltages. Can you supply me with a list of parts, to- I SINGLE !RECEIVE MM5 gether with the diagrane -Adam Poretti, Bethesda, Maryland. MIRES L SEN D L ANTENNA Simple Two -way Intercommunicator -1161 Inter-t' ation System

I wish to connect two single- button mikes and two small magnetic speakers in such a manner that inter-communication can be carried on between a room on a second floor in my home and the kitchen, which is on the lower floor. If possible, can you show by diagram the simplest way this may be acconplishede -H. A. 325 Stebbins, .Madison, Wisconsin. (EACH) R1' 10.000 is a diagram using a of amplification for 0,005 A. Here simple stage 1W. two mikes and two speakers. Both switches are located in the master unit, which may be used in either room. It is a simple Low Cost, Low Power Ham Transmitter -1163 affair and makes a satisfactory two -way communication system. A. Here is a diagram of a simple crystal control "Ham" trans- Set Squeals mitter using a 6L6 tube. All parts needed are shown in the sketch. Recently I have constructed a four -tube TRF, regenerative receiver. After adding an audio power stage, squealing and body Treasure Locator capacity were experienced when the regeneration control was advanced. Can you suggest anything to remedy this? -Tony Pic- Can you inform an ardent reader of your magasine what colo, Ogdensburg, N. Y. issue of SHORT \ \"AVE & TELEVISION contained an article on an Ore, Pipe and Treasure Locatore-Chas. Meehan, Fort Worth, The trouble you are experiencing is due to R.F. getting into 'A. Texas. the audio section. We suggest that you try placing a .002 mfd. condenser from the plate of the detector to ground or B minus. A. An article on such a radio device appeared in the issue of Refer also to diagram number 1131 in the June, 1938, issueof May, 1937. Write our circulation department for a copy. SHORT WAVE & TELEVISION. If this does not help, it would be best to change the complete layout of parts. Hata on 3 Meter Antennas Two -Element Detector Do antennas for 5 meter work differ in any respect from the Circuit antennas that are used for 40, 80 and 160 meter work? How are they determined, and is there any book available in which one may I wish to use a two-element secure some data with reference to the problems in designing such detector circuit in a receiver that antennas especially for 5 meter or ultra -high frequency world.- I am constructing to cover the Allen Johnson, Philadelphia, Pa. 2000 to 3000 kilocycle band. A. The problem of designing an antenna for the ultra -high fre- Could you supply such a detector quencies in the neighborhood of 5 meters is in no respect any circuit, giving the coil -condenser different from those used on the lower frequencies. Antenna lengths combination? i intend using two are determined in the same fashion. tuned feeders remain multiples stages of tuned radio frequency of a quarter wave, and matching systems are treated in the same amplification for local reception. manner. Ultra -high frequency antennas are, of course, much -Nathan Lefkowits, Lafayette, smaller than their lower frequency counterparts and it is therefore Indiana. Diode Detection -1162 more readily possible to observe their performance with a neon bulb or galvanometer. A. The sketch shown here illustrates a grid -leak two -element UAW detector circuit. Either a D.C. filament tube or an A.C. heater tube SOURCE may be used and as all common receiving tubes deliver about the Photocell Relay Circuit \1I' same results, the choice will depend largely on the filament voltage supply available. The grid and plate of the tube are connected fIn the October issue of together as one terminal and the cathode or negative side of the RADIO & TELEVISION there ap- filament serves as the other terminal. If a heater tube is used, it peared in the Question Box a is well to bias the heater positively with respect to the cathode diagram of a simple photocell to prevent hum. relay circuit. I would like to The condenser-coil combination in each tuned circuit will have obtain a, more sensitive circuit, about 37 microhenries inductance and may be made by winding using a stage of amplification. 20 turns of No. 28 enameled wire on a 1/ inch diameter insulating I intend to use this for starting tube. This is the tuned secondary. The condenser for this should and stopping a motor. Can you be .00025 mf. The primary may be 20 turns of No. 30 enameled give complete list of parts? 12 wire if screen grid tubes are used in the R.F. stages and turns -Alfred Barthy, Tampa, Fla. P-E Cell Circuit -1164 of the same size wire if three -element tubes are used. Ten turns of No. 32 enameled wire can be used for the input of the antenna A. There is no reason why a stage of amplification cannot be coil. In each case the primary may be wound directly over one end used with a photocell. Here is a diagram for a photocell relay of the secondary, with a layer of paper between both windings. circuit which is slightly different from the one shown in the Two stages of R.F. amplification are usually recommended for October issue, and which is suitable to operate a motor. The cir- local reception and three or even four stages for long distance. cuit shows the parts that are needed. 482 RADIO & TELEVISION

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not been since he was \V9LZO. He will cone on. pletely isolated from the headquarters station. on 160 meter Pone, and does some experimenting and the citizens of Oak Cliff were unable to phone with a 5 meter rig. Local in alarms to headquarters. HAM Gossip Deputy Chief L. M. Long of the Dallas Fire Department. remembering that the Fire Marshal. Amateur Activity in Baltimore (Continued from page 471) L. M. Funk, numbered among his friends a host 3 -AI13 is back on the air with phone, operating of amateurs. called on him for assistance. To- on 14158 kc. 3 -1K is still fooling with 56 which uses no insulation other than air and is gether they contacted Bob Hutfhines, W5OL, of megacycles. 3 -FAM occasionally on 14 meg. 3 -CB\' working F.B. He will give the info to the gang Oak Cliff. who dug up an old 160 meter rock works only foreigners on 14 meg. 3 -FXU rebuilt sonn in a magazine article. crusher. and is on 10 meter phone. 3 -11G working 10 meter "Ben" Franklin, W2GRG. on 20 has his new The Fire Marshal then made another run to phone. 3 -CJH put up 2 -sect. 8JK for 20 CW. rotary beam working fine now and with his 1 k.w. his residence and brought an amateur receiver 3 -GNB a new one to be on 20 CW when LE behind it. is going places. We had an opportunity to the Fire Department Headquarters, where he finishes the rig. 3 -CDZ says he will he on when to work many of the local gang, including W2AN. tuned in W5OI., and then through KVP.,the he gets new receiver. 3 -ASZ is hack after an whom we used to work when he was \V8AQZ Police & Fire Radio Station, two -way communi- absence of about 5 years and is on 20 phone. in Ohio about 15 or more years ago. These local cation was resumed to the Oak Cliff area. 3 -FWU is going to rebuild for 10 meter phone. rag -chews are really worth while. Among the Directions and instructions were sent out from The 28 meg. band is really opening up here. stations contacted were W2JZO, W2 IE. W2LEJ, headquarters over KVP, and all of the Oak Cliff And I understand that there are going to be \V2CDL. W2JDS. W2GDP and W2KDS, all equipment and stations replied by telephone to about 18 new stations here with 1 KW rigs soon! putting in fine signals. W5OL, where Bob relayed the information to We expect a lot of new fellows to get licenses Ten meters has been picking up somewhat. headquarters over his station. WSEQJ. Odis here in the very near future. Well, when I get although not up to what it was a few months Peacock, assisted in keeping things in order. the "final" hooked up and couple it to this ago. Seems like a lot of old timers are working This two -way communication was continued 2- section 8JK beam I have up here. guess I 10 steady and doing a good job. Included among throughout the night, and just before day the won't have to worry much about it anyway. I them are W2AOG, W2AWC. W2TP. \V2HMK workmen completed the repairs to the Fire Depart- have worked LU. V K, ON, OQQ, VP, VS. XZ, and W2ISY. J. T. Wilcox, 500-9th Street, ment lines, the emergency was declared ended VE -1. 2. 3, 4, 5, XT. T1. CO, HC. SU. VR. Carlstadt, N. J. and W5OL pulled the switch. F. G. SV. W10. HH. K6, HA. VU, J. XE. CN, PA. PK. VO, VN. CI, KA. YR. GM. ZS. Report from L. M. Funk, Fire Marshal of "73 Club" New York SM, HR, CW, and AC since last November with Dallas, Tex. W2DTT this 200 watts input. All worked on 20 meter phone. Totals are 28 zones and 43 countries THAT part of Dallas, lying west of the THE "73 Club," one of the livest amateur compiled. -Louis Charles Bremer, \V3LE, 130 So. Trinity River, and known locally as Oak Cliff. radio clubs in the metropolitan area of New Broadway, Baltimore, Md. is within itself a metropolitan city of 120 square York, is laying plans for what promises to be a miles area. This vast area of approximately 100.000 very successful season. York and Vicinity people was suddenly cut off from all means of If you 20 meter phone "hams" haven't con- New communication from Dallas proper about 6:30 P.M. tacted Miss Ruth Feldman. who daily operates W2CLS on Sunday. October 9, 1938 when a fire of un- W2ASA, as yet, do so, for this "gal' just dis- MET Laurence Cockaday. W2JCY. few weeks known origin broke out. seminates oodles plus of personality and interest. ago and he had just finished a new H.F. antenna The five fire stations in Oak- Cliff were cons- -Alvin Abrams, W2DTT.

for December, 1938 Please say you saw it in RADIO & TELEVISION 483

www.americanradiohistory.com 1 -Meter Waves with Ordinary Tubes

Nelson G. Haas and Carl A. Erbacher

Ultra -high frequencies are attained by using such standard tubes as the 27, 37, 56, or 76, in conjunction with old parts, found in any workshop.

were in the region of from urge to use larger tubes and higher powers, one to five meters. Marconi, be careful in the applications the outputs are seeking a practical develop- applied to! ment of Hertzian waves, turned to the more readily The human body resonates as a half full used wavelengths above 300 wave, at about 3% meters, as a wave meters for his first experi- at 1Y4 meters and as two full waves at a little under one meter. Which means that A- Antenna system for 1 -meter oscillator consists of antenna, ments. The phenomenal suc- a 15 or 20 watt even on 3% reflector and director. Output meter is placed in beam. cess at these wavelengths with oscillator, favorable B-The completed I -meter oscillator. Note simple layout. focused the eyes of all ex- meters, the body will, under con- C- Another neat layout. Using a 45, 71 or 210, this rig perimenters for many years ditions, resonate sufficiently so that a sec- afforded more power, but would go only to 1.6 meters. lamp on the longer lengths so ond person can light a small neon on that, until a few decades one's nose or ears, or toes, points of maxi- Exposure more VACUUM tube oscillators on a fre- ago, nothing more was known of the very mum voltage. to power would very likely raise internal quency of 224 million cycles per second, short, or Hertzian, waves than was known than this the of the body and, if sufficiently antennas less than a foot in length, radio at the conclusion of those early experi- temperature powerful, destroy the body cells. So best signals carrying speech or music steered ments by the man who gave his name to and bent around corners, much as beams of them. light would be -these are the interesting For a long period following a return of characteristics of a band of ultra -high fre- interest in Hertzian waves, scientists found quency waves that can be generated with the no particular use for them, and their char- simplest circuits and the most common vari- acteristics remained an abstract proposition eties of tubes -the wavelengths around one -something to know about, and nothing meter ! more. The advent of the acorn and the Useful radio waves, the length of which door knob type tube a few years ago re- can be measured by a yardstick, aimed in awakened the experimenter's interest in the exact direction one wants, to a receiver Hertzian waves but did little else -for he beyond the optical range; the entire appara- immediately bumped into the stone wall of TO MODULATED tus, including the already assembled antenna far -too -expensive equipment. R.F.C. PLATE VOLTAGE arrays, can be packed into a fair sized soap But from the commercial laboratories, ti 250 -3C0 V. box. In the many years the writers have with their theory -trained workers, their been engaged in the radio game, building, resources of specially designed tubes and B testing and operating their own stations. associated equipment, have come some in- L - L t V4 COPPER TUBING 4 LONG never have they encountered a phase of teresting circuits and results. It is the,, C - 1S MMF. MIDGET COND. VARIABLE R 10,000 ONM6, 1 WATT. half so fascinating, or nearly so in- circuits and accomplishments that th, R.F.C. 25 TURN Ne µ, 3 /8.01AM. radio R.FC.1 30 2/11,2/4. structive a laboratory test for the develop- writers have endeavored to utilize by in- V.T. TUBE TYPE 27, 3,37, 76 ment of equipment such as oscillator cir- corporating the most salient features with cuits and antenna -receiver performances, the usual ham, or amateur, practices, at Schematic diag -am and list of parts used in dielectrics, etc. the same time keeping to the reputedly constructing the I -meter oscillator, utilizing For instance, it is but the work of min- less efficient older and far cheaper types of sfandard receiving tubes. utes to set up an experimental antenna tubes and dielectrics. The results have been array and take field strength readings when more than satisfactory to us so we pass stick to the apparatus described until one the antenna can be measured with a 12 -inch them along to the reader, the man who is becomes thoroughly familiar with the char- ruler. And the most convenient part is that tiring of the commonplace in radio and who acteristics of tie waves around one meter ! all the apparatus needed is readily available, wants to delve into the last unexplored since it is the same type parts used in con- frontier of radio development. Having decided to adopt modern labora- structing higher wave equipment. But little A line to caution the too- enthusiastic ex- tory practices now used in ultra -high fre- room is needed for this sort of work, a desk perimenter seeking unusual or startling re- quency work to equipment readily available top offers ample space for transmitter, an- sults. The powers generated by the tubes to the average experimenter, the writers tennas and a receiver. specified in this article, while ample for lost little time in finding which of the many The first radio waves generated by that observation and communication, are com- possible circuits would prove the most suit- eminent physicist, Heinrich Hertz, in 1887, paratively minute. Should one have the able. All the basic oscillating circuits pre-

484 RADIO & TELEVISION

www.americanradiohistory.com viously used in commercial laboratory circuits were quickly wired up and tried. Comparison showed that only one, the split - Colpitts, or ultra -audion oscillator, ap- proached a satisfactory standard when using ordinary triode tubes. The ultra- audion circuit chosen discards the familiar coil and GREpT condenser combination, used to obtain ' WO'S resonance, and -borrowing laboratory technique-uses instead resonant "long lines" pM GUIDE made of tubing to tune both the plate and grid circuits. VIN6 The tubes at first were of the receiver LTX 1111110 audio output type, such as 171s, 112s and finally, in an attempt to increase power, 245s. All these tubes oscillated without any coaxing on waves as short as 1.6 meters. While using these tubes we discovered that they handled much the same as they would on 5 meters, insofar as output was concerned. For checking wavelength, a simple ver- sion of a Lecher wire system was used. This comprised a 6 -foot length of 1 x 2 inch lath to which were nailed 2 lengths of bare rn:: No. 14 copper wire, terminating at one end in a U- shaped loop and left open at the 188 PAGES OF GREAT VALUE other end. A flash-light bulb and socket, to which were fastened 2 clips on very short UFAY'TIt Your leads, made up the "bridge" to short the buying wires and so get a possible reading. guide, and a say- To determine the wavelength the loop of ing guide, too. the Lecher wires is placed in close proxim- ity to the transmitter and the bridge is That's the story be- slid along the wires, starting at the loop hind this new FREE end, until it indicates the maximum current catalog. To bring you point by the flashlight btilb lighting most brightly. From that point on the wires to the latest, the best in the loop should be exactly half a wavelength, 1939 Lafayette radios, and can be measured off with a ruler, allow- parts, tubes, Public ing, of course, 39.37 inches to the meter, so as to get the wavelength in meters. Address equipment, An antenna cut to resonance and having and amateur appara a flashlight bulb in its center gave some tus at thrifty indication of output that could be used for -all comparison, but a field- strength meter, such prices. There are over as the writers described in May, 1938, 50,000 items in this SHORT WAVE TELEVISION & as a crystal great book, and every rectifier unit, proved invaluable for making field -strength measurements. single one a standout buy! Mail coupon today The super -regenerative receiver we used for your FREE copy. Wake up to sensational values! tuned down, when checked by Lecher wires, to meter 3 and the detector tube in it, a > J> i 56, oscillated smoothly at that short wave- TAKE THE GUESSWORK OUT OF YOURh length. The cylindrical plate in a tube of the CHRISTMAS SHOPPING WITH THIS NEW type such as the 56. 27 or 37, insures a far lower grid -plate capacity than is found in the type tubes first used in the transmitter. CATALOG The transmitter shown in the accom- photograph panying was then constructed. ES1E RADIOS i;;34;;Zr-i=cL41.5:211=QQ4 ..+ Its details can be readily ascertained by studying both the photograph and the dia- 939 To make your 1 SYSTEMS Christmas shopping easier, to gram. From the start it was successful be- ADDRESS enable you this year to give beautiful, worth. yond our expectations. In wavelength it WC while gifts at money saving prices, we offer & TUBES would tune down to about 3 of a meter, PARTS a special FREE Christmas -shopping catalog. all the while running cool and stable. In 50,000 Send for a copy today. ft's crammed full of fact, the signal from this transmitter, when APKIMICES electric trains, cameras, modern appliances, tuned in on the super -regenerative receiver, ELECTRICAL electric shavers, radios -gifts for Mother, stayed in one place on the dial for hours APPARATUS Dad, Junior, Sis, and the girl friend too. Mail of constant checking. The 56s in both re- AMATEUR the coupon today. It will pay you! ceiver and transmitter, neither of which KITS were being operated at more than 200 volts, TELEVISION branches to serve you did not drift enough to necessitate retuning 7 the receiver. This on one meter, without the CAMERAS aid of special tubes and equipment usually NEW YORK, N.Y. e CHICAGO, ILL. ATLAN , believed necessary for successful operation TA GA. BRONX, ' N. on that wavelength! BOSTON, MASS. Y. NEWARK, N.J."C1,11,1S JAMAICAL. I. (Next article covers receiver) Valli 'Bill WHOLESALE RADIO SERVICE CO.. INC. sas; 100 SIXTH AVENUE NEW Yvon min* YORK, N. Y. Radio Talks from t Rush FREE 1939 Radio Catalog No.73 -4M9 Jungle pp!n in r D C; Santa Rush FREE 1939 Gift Catalog No. 75-4M8 D manipulate et the dials. It finally dawned ol,. these her that the voice was coming out of th, Name radio apparatus." and books se e The greatest curse of tropical radio, ac- for Address cording to Hungerford, was the insect. The - alrrse /f nightly yield of electrocuted bugs averaged City State one quart. PASTE COUPON ON PENNY POSTCARD for December, 1938 Please say you saw it in RADIO & TELEVISION 485

www.americanradiohistory.com How to Build the ,o5 e,\'1 W8KPX *R)i-c"

Harry D. Hooton, W8KPX

High in efficiency, low in cost, this Selective and Sensitive 4- tube Ham set affords band spread on Five Bands.

SINCE the publication of the "W8KPX" tubes, with regeneration in both the R.F. Beginner's Transmitter article in the and I.F. circuits. Using only two metal and July, 1938, issue of RADIO & TELEVISION, two glass tubes, the results, so far as sen- the author has received a number of requests sitivity, image frequency rejection and selec- from Ham beginners and would -be Hams tivity are concerned, are actually better than for constructional data on a companion those obtained from most 6- or 8 -tube re- Beginner's Ham Receiver. In each case ceivers using the conventional superhetero- the writer specified a set capable of efficient dyne circuits. Briefly, the line -up consists of five -band operation, with plenty of sensi- a 6L7 regenerative mixer, a 6C5 high - tivity, selectivity and bandspread, easy to frequency oscillator, a 6P7G as I.F. ampli- build and operate and. finally, of the lowest fier and regenerative detector and a 6F8G cost consistent with the desired results. as two stages of resistance -capacity coupled A.F. amplification. The iron -core, 465 kc.,I.F. 4 Tubes Do the Work transformers give an appreciable increase The little 4 -tube dual- regenerative super - in gain over the ordinary air -core types. het to be described here has been designed Regeneration :s introduced into the mixer especially for use with the 75 -watt trans- circuit by means of a few turns of "tickler" mitter. and is ideal for either the new- winding in series with the 6L7 cathode and comer or the dyed -in- the -wool "old-timer" coupled to the "cold" end of the mixer grid who wishes only a simple, low -cost receiver. coil. The regeneration control for this cir- As the diagram, Fig. 1, shows, the circuit consists of a 5,000 ohm potentiometer Top: A rear view of the W8KPX Special. cuit has been worked out around the new shunted across the cathode coil. It is Below: Top view, showing layout of parts. 6P7G pentode- triode and 6F8G dual -triode (Continued on opposite page)

Schematic and picture diagrams, below, make the wiring a matter of but a few hours' work.

NOTE TICKLER R.F.C. C SEE , 6L7 20.000 I.F.T.1. 6P7G 01- ANT MIxER OHMS 465 KC L.F. 4 DET. IFT.2 MF. / .Ol- MF. i 4 6 !00 35 5 MMF MMF. loo MMF. MEG r MMF 3014 t CM.

Ol- 1,1 MF. 0.1- MF. 3MEGS oNO. L'15 / ÓwMOS T T .^ OHMS 300 0.1 -' L10 OUTPUT ¡/Ipp 50.000 \O.1- 0.1- 25.000 '2.000 '-IO TICKLER MF. MF. OHMS MF. OHMS MF. /OHMS 20,000 (EACH) -50.000 -óßs I / Ó5C 13+ .L OHMS OHMS -. \ 'OAF .` 50,000 SEE l 400V. OHMS NOTE. 75.000 0.25- 50.000 OHMS R,F.C. (20.000 OHMS MEG NOTE: OHMS T .01- ADDITIONAL 140 MF. SW 1/ MMF. COND. INSIDE 40, /30, 1GO METER 250v G COILS ONLY - 6..3 , B. B+ SUP PVLY

IFT 1 C.01-MF 0.1-MF 6F8G A F. 6L7 465 KC 1FT2 M, %ER 6P7G / TRIMMERS 20.000 E R.FC / OHMS OCT. 500.0A00 SO000 .5- TICKLER Owns MEG.

GRID

OUTPUT 10 F COIL - 50405 CORE 0.1 -/ MF. '2.000 TICKLER (_ f ACH) 75,000 2OHMS 103" 1 MF Cr OHMS 400V PLATE TRIODE R.FC GRID TRIODE SÓHrOwb VT

C20.000 SPACING GNO. O1 OHMS TICKLER. SOT060 TURNS MF GRID / PLATE PENIDDE N432 SILK COVERED %IRE COIL JUMBLE WOU 40 MEG. -NOW TICKLER IS ADDED ER, t ( 26oV.'B TO Sw.l B } 70 21íP. L.F. TRANSF. ^ FIG.3

486 RADIO & TELEVISION

www.americanradiohistory.com If you order any of the sets described below NOW, we will guarantee that your set will reach you in time for the holidays. We built up a stock to take care of rush orders. Act promptly.

THE NEW AND IMPROVED DOERLE MODEL D -38 A. C. l7!í x 8t/2 = 8%z 7 Tubes 4t/2 to 3000 Meters The last word in short wave receivers. Before you buy send for circular D -38, an eight -page booklet containing schematic and picture diagrams, instructions, and sketches. Read this booklet and compare with the other models you have in mind. Then send your order to the concern who in your opinion is giving you the best for your money. Complete, with all coils, and tubes, no extras $32.50 Kit, factory assembled, but unwired, less tubes, with all coils $22.50(e

7C 5 -Tube 3 Tube Electric Model, com- Short Wave Receiver 814 to 625 meters plete, tested and ready to use, Bigger and More with 5 plug -in coils, 12 to 600 Powerful meters, at $6.50. Than Ever A Giant in Perform - ance

Our Model 7C, Midget in Size Giant in A -A BS -5 Six tube Bandswltch Receiver. no plug-In- coils, Performance. One of our most popular short select the band by a simple flip of the snitch. wave receivers. Loudspeaker Operation Our files contain many letters from satisfied lis- 12 to 000 meters, automatic headphone jack also teners from all over the world which testify to the included. popularity of this set. and their lists of DX stations Complete, ready to use. including tubes, factory aired Kit form, factory ayYr in bled. but unwired. with ereised on the loudspeaker is amazing. d laboratory tested. 818.50. coils. less tubes. $3.50. Complete kit. factory assembled. ready to wire, in- Available in battery model at same prices, if I ,es a 51K radio- frequency stage. a OFT. twin 2 rluling tubes and cabinet. $10.50. specified. If tubes are desired. add $1.50. n 1 tube, as regenerative detector and first audio. K9e 6C5. one t2ST. twin 2 In 1 tube. and one 2A. Earphone pack has been incorporated to permit the use of phone when loudspeaker operation is not I SEND 10C FOR OUR NEW CATALOG containing CIRCUIT DIAGRAMS. desired. Operates from regular house current. FLASH and complete information on over 25 different types of short wave receivers and transmitters from $2.50 and up. This catalog is chock full of schematic and ',me ipiete v with all coils. fit. to 000 meters. and all Picture diagrams, hook ups and short wave information. A book in itself. welI worth nines. ready to use. nothing else to huy . $16.50 the dime, which be in Kit form, but factory assembled. including all will refunded with your first order. 1 rolls and tubes. but unsolved $12.95 L Avallshle in battery model upon special order at same price. Also available in ham model with special tun- 68 Barclay Street, Dept. 12 ing circuit to provide add lriunal ban.lspread ut $1.00 OSCAR B. additional. KUSTERMAN :: New York City :. t YSx b ï42i ï5ti EZ 45VS i5~f I'S 5t= ï4.`K MS äS:Y 35^S ó^S ?4tsszï-CK?S:tïCfbmazmafiSïSScw:4.SïSf ï^-Srs:fö(ï

www.americanradiohistory.com H. G. CISIN'S Build this 4 -Tube HAM FAMOUS KITS Receiver DAT, 1l'RlNTS (Continues jniill J uui'ding page) Only 33 %c each BRUSH in orders of 3 at $ f 1939 1 crystal headphones -Pair BUILD YOUR OWN -SAVE MONEY I RCA (Tubes) RADIO CONTROL 1 -6L7 (metal) 1 -6P7G (glass) FOR MODEL BOATS, 1 -6C5 (metal) 1 SPACE EXPLORER -6F8G (glass) PLANES, ETC. All -Wave All Electric A. C. -D. C.) CENTRALAB )Resistors) Clrcult data 50c 4 -Tube Receiver 1- Volume control, 5,000 ohms 1- Volume control, 50,000 ohms with SPST switch SEVEN BANDS - 3 resistors, I watt, 50,000 ohms lo In 2000 meters. -Fixed 0 ELECTRIC LODGE & Professional ltand 3 -Fixed resistors, 1 watt, 20.000 ohms PARTY TRICKS. Fan Spread Communica- 1 -Fixed resistor, 1 watt, 25,000 ohms Galore! tion Set. 2 -Fixed resistors, 1 watt, 300 ohms Powerful, Sensitive 2 -Fixed resistors, 2 watts, 2,000 ohms "How to Do 'Ent" Data 50e and Selective. Full 1 -Fixed resistor, 2 watts. Vi megohm loud speaker volume. 1 -Fixed resistor. 2 watts, 75,000 ohms front as Reception 1 % watt, ohms S -W DIATHERMY many as 39 foreign -Fixed resistor, 50,000 stations in a single 1 -Fixed resistor. Vi watt, 0.5 megohm (Artificial Fever) evening reported and 1 -Fixed resistor. % watt, 1 megohm verified by many 1 -Fixed resistor, 4 watt, 3 megohms Dataprint giving Constructional owners. tata for Small. Medium and Large glee App. (All 50e t .. Foes one 6C6, one CROWE 3).... -7 -- 76. one 12 -A 1 -Dial (Micrometer type, 270 degrees) (Twin -Tube) and one Metal IC105- A as regenerative detector. powerful two -stage pentode audio amplifier, half - Induction P PE & ectifier and automatic ballast stage. Self- contained MISCELLANEOUS power r supply operates on 105420 volts. any frequency 1- Filter choke, 50 ma., 30 henry ORE LOCATOR e.c. or d.c. interchangeably. Built -in chromatic speaker 4- Pointer knobs Construction Data 50e phone jack, antenna control, full -vision airplane type 1 -Steel chassis, 7 x 13 x 2 inches dial. band spread variable. dual regeneration control. sturdy metal chassis. Clear explanatory diagram sturdysimplifies s tal RECORD VOICE OR Complete Kit of All Chassis Parts, l'oser 95 CODE on Steel Wire! Supply and Diagram I into lied, less tubes S. W. League Telegraphone Data, for coils and speaker) Voice or Code 50e Wired and Tested $1.50 entra. Four Matched Tubes. (Continued from page 470) E2.45. Four S.W. Polls 10 to 200 Meters El. 2 Beast Coils. 200-530 ni 51 long Ware Coil 330 to 2000 Meters Lester Fuller, Jr.- Observer for Arizona 81. Tru- Flitch t y i'lu aman is Speaker 81.45. TESLA COIL DATA: Call Freq. R S Call Freq. R S Data print- drawir.gs and data for KAIZL 14.070 4 7 PK6XX 14.020 5 8 building 30.inch spark Tesla SOc KAIJ\I 14.075 4 7 PK2AY 14.250 3 5 E xciter -I K.W. 25,000 Vt. Trans( N. G. CISIN'S All -Ware Air Scout Jr. Radios e KAI KK 14.075 3 5 CNIAF 14.080 3 5 3 1:Wk. Tesla Coil. Works on For, 20 7 VK5MF 4 6 ZS5AW 14.080 4 14.- 3ASék. Oudin Cou. Works on THREE -TUBE WiTH VK4BJ 14.- 7 8 VK2NS 14.000 5 8 Ilia 20 "Tricks" with Teslas a Oullins ALL ELECTRIC Romney Miller- Observer for Rhode Island Sp'k. Tesla Coil Soc Tubes Call Freq. R S Call R S S ALL WAVE SET Unwired Freq. S adler K.W. 15.000 Volt ZL2BE 14.10 5 7 VS6AG 14.08 5 6 t -Ve MODEL ..4 -t Violetta Oudln. Vibrator KA7EF 14.15 5 6 MI 14.10 5 6 -1 Spk. n I ii itiS, air :,., et. Hold, wonderful ., Also brings police VK2NS 14.02 5 8 NF 14.05 5 8 Hopto Operate Cueing -from V, rectos, ii foreign reception. in e. 50cT. calla, amateur. cede. reTr`nsatlantic phone and broad - VK3EH 14.05 5 7 'Y2AE 14.25 5 8 cas entertainment.e Excellent vol- -s- Works from any A.C. VP2LB 14.13 5 7 ZS5AW 14.08 5 7 ú:c." house current. Easiest set SM7YA 14.07 5 8 ZS6AJ 14.015 5 9 More DATAPRINTS You Need! Rater Turbines "Rewinding" Armas.. the tubes.eballt SpeakerbaastEaslonof ubeoemounts on ttractive Ed. Davenport -Observer for Vermont Rater Wheels Induction Balance panel. Range O i to 610 Call Freq. R S Call Freq. R S 100 Mechanical Movement. Telaulograph r to 1500 meters with special Motor Circuits 1201 Einthoven String C.: long wave coil. Complete Kit In. VP2LC 14.13 5 7 VP7NS 14.17 5 4 Telephone Hookups (20) nometer eludes: a Earphone. broadcast coll. Polarized Relay, Ultra. Magnets and Selene] 70 200 se coil. Panel. Bob Tagiauer-Observer for Kentucky list before order] MODEL 35.E Chassis. High Grade Variable Call Freq. R S sensitive Get Pat. No. 2,055.238 Condenser. Call Freq. R S Ring 4 bells on 2 wires Wheatstone Bridge Dial. Sockets, y VR6AY 14.350 3 4 VK2GU 28.150 5 8 Rook Induction Coils -1 to Wire. Resistors, Condense and all other required pans 20 Simple Bell -ups With Phone (Less ZL2DE 14.150 4 6 PAOFB 28.180 5 7 Electric Chime Ringer fits inch SD'k data including instructions and a die- t3.20 any clock Pipe Thawer gram. ONLY tubes, unwired) VK2NS 14.020 5 7 G5VM 28.185 5 8 Electric ONE.TUUE BATTERY SET -Model 15. Satisfied owners VK4VD 14.145 5 8 GSLJ 28.180 5 8 Welding Trf. 2 K.W. 110 V. Prim. 18 V. Sec 50e broadcast FOREIGN RECEPTION. other VP7NU 14.045 5 7 28.150 5 3lw. and model G5SI 6 5 prints 51.50 er 10 for 82.00: single prints 50e Earphone reception. Complete kitmincluades parts listed VP7NS 14.075 5 8 G2ZV 28.190 5 6 above plus 30 tube and filament rheostat. Uses inexpen- VP6FO 14.085 5 7 G2VM 28.190 5 7 Tube d The DATAPRINT Co. sivenive batteries $2Á5 Phone (unwired) VP1BA 14.115 5 9 G8SA 28.105 5 9 Lock Bor 322 RAMSEY, N. J. TWO -TUBE BATTERY SETS-Model 2E. Complete kit Bill Arkansas Including all ians in the 1 -tube model plus _parts for Henderson -Observer for extra ge With Call Freq. R S Call Frea. R S eluding power t tube in V295 S Phone (unwind) VK2NS 14.02 5 8 VK3VW 14.03 5 6 THREE -TUBE DE LUXE BATTERY SET -Model 35. Corn. VK4JP 14.30 5 9 PK6XX 14.20 5 9 plete kit including all parts in the 1 -tuile model plus Parts for two extra audio stages including two 31 -type tubes and 33 With Three Tubes Jack Wells- Observer for Alabama Formulas and Recipes power output tube $3,45 S Phone (unwired) Call Frea. R S Call Freq. R S Following Auxiliary Pans are available: Sty to 20 /foreign, 25c: 40 VOII 14.11 5 7 PRIVY 14.08 5 8 FOR THE PRACTICAL MAN meter coli 25c: 15 to 45 ete ,il 4 5 to RO meter 11 foreign) 25c: r 22ií volt "B" battery KAIZL 14.26 PK6XX 14.009 5 7 75e; Two flashlight A" flatteries for ch: 5 Find. VR6AY 14.345 5 5 CN8AV 14.12 5 7 OF BOOK all Loud Speaker 51: Complete Antenna Kit 50c: Wood CONTENTS KR 10c. Tubes for Model 3A -F. each 35c. Long K5AH 14.26 5 7 CNIAF 14.278 5 8 Wawve Unit and coil for any model SI. Double Earphones NY2AE 14.20 5 8 VP7NS 14.09 5 8 1. Adhesives: Glues, Cements, Gums, Muci- $1.30. Bandaprea Attachment 75e. Any Air Scout Jr. model wired extra 51.00. ZBIL 14.14 5 5 SVIKE 14.00 4 7 lages, Lubricants. 2. Cleansing: Stain Removers, NOTE: If you already I c two extra foreign PAOEO 14.135 5 7 ZL2BE 14.215 5 6 Paint Removers, Bleaches, Cleaning Fluids. 8. Ils may tien substitoit,- .., i..d. 1. flashlight tells. FA3HC 14.04 5 6 VK2ARD 14.515 5 6 Metal Craft: Coloring, Oxydising, Plating, Re- EA9AH 13.99 5 9 TG5 14.05 5 7 pairing, Welding, Polishes, Alloys, Solders, Amal- From Observer Wells I have learned the ORA gams. 4. Paints: Colors, Stains, Varnishes, Enam- of CNIAF. Address reports to this station as els. Luminous Paint, Washable Paint Paint - follows: Sr. Jose M. Sierra -19, Rue des Sources, Removing, Waterproofing, Fireproofing. 5. Glass - AIR WAVE AIR SCOUT Tangier Zone, North Africa. Working: Cutting, Drilling, Boring, Bending, 1 TUBE 3.IN -1 hiT Blowing, Etching, Engraving. Frosting, Silver- R. A. Rush -Observer for California ing, etc. 6. Wood- craft: Fillers, Fireproofing, THRILLING Call Freq. R S Call Freq. R S Acid -proofing, Waterproofing: Furniture Polishes, SNORT WAVE VK2GU 28.420 5 9 VR6AY 14.348 5 7 RECEPTION Finishes, etc. 7. Inks: Recipes, Eradicators, Ink ZL3KZ 28.400 5 6 PK6XX 14.020 4 7 Stain Removers: Special Inks: Colored. Indel- KEEN HI7G 28.450 5 7 S. Pho- BROADCAST ible Sympathetic, Invisible. Hectograph. RECEPTION Ray Halliday- Observer for South Carolina tography: Developers, Emulsions. Fixers, Sen- R sitising. Toning, Printing, Photographic Paper, INTERESTING Call Freq. S Call Freq. R S Rem- LONG WAVE KOLB 28.262 5 7 YVIA0 28.276 5 6 Blueprint Paper. 9. Antidotes for Poisons. RECEPTION HI76 28.270 5 8 K4EJG 28.075 5 9 edies for Burns and Scalds, Disinfectants, First- Aid in Accidents, Emergency Remedies, Home All three t of reception "i this remarkable, low- G6BW 28.268 5 5 priced merely by interchoo._inl' plug-in coils. Coll Remedies. 10. Preparation, Manipulation, Han- Included ¢tin i'kit brings in Broadcasting. Police Alarms Roger Legge. Observer Measuring, Weighing, Filtering, and other interesting abort wave programs. Five outerr Jr.- for New York dling, Mixing. coils available to cover 5 different wave bands. FOREIGN Call Freq. R S Call Frea. R S Straining Solutions: List of Technical Sub- RECEPTION under ltahle conditions. Three foreign 5 7 Emulsifying; Use of Hydrometer, Use t broadcastIDC ZL2BE 28.4 KAIFH 14.27 4 5 stances: i5 7 Tables of Weights and Meas- e 2 Unit a n ti coil 75e. i nfngWavor rphones.Ä ZL2BT 28.35 5 KAICS 14.294 4 5 of Thermometer: operates lloutl speaker on strong stations. Works with any 28.3 5 7 urea, Decimal System, Useful Tables. ye Uses batteries. cell ZL3BV KAIHS 14.29 4 5 tue 30e) requires j2hgnflslihi n small Ss VK2GU 28.3 5 7 PKIVY 14.28 5 7 battery. 5 -vol tube 125c) substitutes storage battery for Postpaid flashlight cells. ZSIAX 28.35 5 6 VK7RZ 14.3 4 6 PRICE 5Oc KitK comes complete with black mounting panel. 1l. all ZS6ED 28.1 5 7 SUTAX 14.03 5 7 Send stamps, cash, cheek or Money Order detailed Instructions ZS6DW 28. 5 7 ZS5AB 14.3 4 6 full sbaryd Pkiure under panel showing exactly where to mount parts and fasten Wire. FA3JY 28.3 5 6 CNIAF 14.278 5 7 H. G. CISIN. CHIEF ENGINEER CN8AV 28.3 5 8 ZBIL 14.14 5 6 T Ia.I:FINIFAX Allied Engineering Institute, Dept. S -SO SPIRO 28.1 4 5 CX2CO 14.01 4 6 Diciaion RT -1238 98 Park Place, New York. N. Y. TG9AA 28.3 5 7 558 W. WASHINGTON BLVD. CHICAGO, ILL.

RADIO & TELEVISION 488 Please say you saw it in RADIO & TELEVISION aa www.americanradiohistory.com Let's Listen In (Continued from page 475) wave, we heard an R5 -6 "sig." with a rapid A flutter, reply to FTM " -iei Saigon, alto -." NEW Edition FZR, on 16.25 mc., used to be a stand -by at 8:30 a.m., but we have not heard it lately. revised enlarged It would be a good bet to try FZR, at 8:30 a.m., Thoroughly -greatly and offering a but begin looking for it at 7 a.m., from which time it has been heard. However, FZR usually works wealth of new up -to- minute information FTK, 15.88 mc., also at St. Assise. Watch FTK daily. a very powerful "sig," and if you hear speech, try for FZR, which puts in a very nice "sig" here, often R7 -8. For these stations. write to Centre Radioelec- trique de Saigon, Postale Boite 238, Saigon. French Indo- China, and you'll earn a very courteous ver,. THE RADIO JAPAN A new sw broadcast signal from Japan is being very well heard mornings, in conjunction with JVN, on 10.66 mc. This new transmitter operates on 9.73 mc., and is almost as good as JVN. It is MANUAL listed as mi the air from 1:50 a.m. on, or same schedule as JVN. Check the sig with JVN's. Both Here's the only complete Hand- carry same program. A new one reported lately is JZO. 10.27 mc., book for students, amateurs, operat Tokyo. heard almost daily from 8:30 -9:30 a.m. ators, and inspectors. It covers The Jap phones are having a busy time of it, as, despite our very limited time spent in piing the entire field of radio in 1,000 a.m.'s. we've heard 'cm very often. JVF, 15.62 mc., heard at 1:15 a.m. and 5:45 pages with hundreds of illustra- p.m. JVE, 15.66 mc., heard at 3:55 a.m.. also tions and diagrams. It is actually 1:15 a.m. JVH, 14.60 mc.. 4:25 a.m. and 5:55 p.m. JVA. 18.91 mc., at 7:05 a.m.. and JIB. a complete course of training in 10.535 mc., at Taiwan (Formosa), heard phoning at 5:45 a.m. This last, a new country distinct radio operation and a complete from Japan. is also often heard carrying musical reference book for in the programs in a.m. JIB verifies from same QRA (ad- everyone dress) as all Jap phones. field. It gives instantly the an- NEW CALEDONIA swer to every question about prin- "Radio Noumea." on 6.12 mc., has lately been ciples, methods, and apparatus of heard signing FKBAA, the call of an amateur there. radio transmitting and receiving. The schedule is now Tues. and Sats.. 2:30 -3:30 a.m., so look for this one, a real mc catch for A - anyone's "lob" QRA is Charles Gaveau. FKBAA, Complete Course 44 Rue de L Alma, Noumea, New Caledonia. in a PHILIPPINES Single Volume KZGH, at Iloilo, has QSL'd to Ashley Walcott. with a courteous letter from Francisco Blanco. the New 1938 Edition station supervisor. Veri states transmitter is in operation daily from 6 p.m.10 a.m.. E.S.T.. in Covers in full detail the Electron Tube connection with local 2 -wire telephones. 400 watts -Vacuum Tube Amplifiers and Oscil- are used. fregs. changed by a dialing system. Five different treys. are used, those mentioned being lators - Modulation and Modulation 6.755, 5.445, and 2.73 mc. Analysis - Microphones - Radio and NEW GUINEA Audio Frequency Measurements-An - tenna Resistance Measurements Latest Broad- VHSU. at Salamaua, was logged testing with - an unidentified VHU4. one morning front 5:30- cast Transmitters with installations, adjustments. 8 a.m., using 3 freqs. This also from Ashley Wal- operation, and maintenance instructions - Latest cott. W6. On 8.07 and 6.54 mc. Marine Radiotelegraph Transmitters and Receiv- JAVA era- Duties of Ground Station Radio Operators - PLP, II ntc., and PMN. 10.26 mc., are really Theory, Operation and Use of Radio Range and "rolling in" here, an R8-9 "sig" many mornings! Beacons (localizers), Landing Beams in- PLE, 18.80 mc. (all three at Bandoeng). logged Marker by G. C. Gallagher, phoning Tokyo at 2 a.m. and cluding Lorenz System of Instrument Landing -Radio Direction Finder-the two 9:20 a.m. U. S. Auto Alarms approved by the F. C. C.- Ultra -high Frequency Police Trans- YDA, 6.04 mc.. Bandoeng, is now relaying mitters and Receivers Important Radio Provisions of the Communications PLP's from 7 -10 a.m. irregularly. -All programs Act of 1934 as amended effective 1937-Rules and Regulations of F. C. C.- CHINA General Radio Regulations Governing Distress Signals, etc. China is using her transmitters very often of late. normal. considering conditions. XTR, 9.40 mc., now at Chungking, is a fre- New Information Never Before Available quently heard signal, from 6 -7 a.m.. or later. with This is just a hint of the vast amount of new information packed into this great a very powerful signal. book. In the entire field of Radio is covered in complete detail, making XTS, 11.44 mc., at Chungking. contacts XTJ. addition, at Hankow, on 11.69 mc.. almost any time of The Radio Manual essential to every student, operator, and inspector. a.m.; lately at 5:15 a.m. One a.m. we heard XTS change over to XTR, probably for a better contact C. C. with Hankow. This happened at 5 a.m. Prepared by F. Expert The author, G. E. Sterling, is Assistant Chief. Field Section, Engineering Dept., DX REVIEW Federal Communications Commission. FED. MALAY STATES- ZGB. 13.63 mc.. Kuala Lumpur. heard lately at 6:50 a.m., with a very fine signal. FREE EXAMINATION SIAM- HSP, 17.74 mc., Bangkok, logged by G. C. The Revised Edition of "The Radio Manual" has just been published. Over 1000 Gallagher, at 2 a.m. and 10 a.m., quite regularly. pages. Hundreds of illustrations. Bound in Flexible Fabrikoid. The coupon MANCHUKUO- TDD, 5.83 mc., Shinkyo. heard is the best phoning at 7 a.m., also TDE. 10.065 mc.. at 7 a.m. brings the volume for free examination. If you do not agree that it TDE is to be heard at all hours of a.m., contacting Radio book you have seen, return it and owe nothing. and phoning with JVO, 10.37 mc.. Tokyo. G. C. Gallagher, W6. contributes this item. Also JOY, Clip and Mail This Approval Order Form 9.93 mc., usually a broadcaster phoning at 9:20 a.m. FORMOSA- JLB, 10.535 flic., Taiwan. relays ED. VAN NOSTRAND CO., 250 Fourth Ave., New York JFAK, broadcast band transmitter, daily. 9:05- Send me on approval THE RADIO MANUAL. Within 5 days after I receive the book, I :55 a.m. Gives news in English and Japanese. can return it and owe nothing. If I keep it, I will send you $2.00 as first payment and I will Same program on JFO, 9.636 mc.. which operates pay $2.00 monthly thereafter for 2 months -$6.00 in all. (5% discount for cash.) (R. &T. 12.) from 4.10:30 a.m. This from OM Gallagher. Name INDO -CHINA -Radio Philco, at Saigon, reported on 6.21. 9.72, and 11.71 mc., at 7:30 a.m. by OM I Address Gallagher. I City State CHINA-XGJ, 11.68 mc.. Hankow. "The Voice Reference of China." broadcasting schedule 7 -7:30 a.m. XGOW. 9.30 me.. Shanghai, broadcasting 7:30 I Address a.m. and heard shifting to 9.19 mc. From G. C. FOR FREE CATALOG of best books of practical instruction and technical information Gallagher. Lcheck here. If you do not want The Radio Manual cross out paragraph above. (Continued on page 509) for December, 1938 Please say you saw it in RADIO & TELEVISION 489

www.americanradiohistory.com SUPERIOR PRESENTS TWO INSTRUMENTS RADIO Test Quiz??? from its new 1100 series!!!!series! (Continued front page 467) a. Increases the voltage in a. circuit sev- Never before has Superior uttered so much for so little: Always the bust buy in the Instrument eral fold. in new 1100 series gives you even more value! We have Field, Superior this incorporated b. Increases the of a many refinements, many new features . all proven to be sound and practical. We urge range voltmeter. you to read the descriptions below carefully; see how these instruments fit your needs. Buy c. Increases the effective voltage in a direct from manufacturer and save 50%. plate circuit. d. Increases the apparent voltage in a The New Model 1130 -S SIGNAL grid circuit. GENERATOR 18. When a radio engineer tells you that your new apparatus should have P -B T, with Audio Frequencies you know he cleans a. SPECIFICATONS: Pre -band transmission. b. Pretty-bum trimmers. 1. Combination R.F. and Audio Signal Generator, R.F. 100 kc. c. Push -button tuning. to 100 Mc., A.F. -100 -7,500 d. Prime -1 /u tubes. cycles. All Direct reading, all by front panel switching. 2. R.F. and A.F. output inde- 19. A radio compass, as used on ships pendently obtainable alone or and planes, is very useful, but you'd be with A.F. (any frequency) modulating R.F. 3. Accuracy is wrong if you said that it is within 1% on I.F. and Broad- a. A compass which is corrected by means cast bands; 2Ç on higher fre- of a' radio beam. quencies. 4. Audio frequencies in 5 bands; 100, 400, 1000, b. A means of determining the position 5,000, and 7500 cycles. 5. Giant of a plane or ship through the use of airplane full vision, direct - triangulation. reading dial. 6. Condenser and other leakages tested to 100 c. A loop antenna operated to determine megohms. 7. All services on the craft's direction front a transmitter. 90-130 volts A.C. or D.C. (any d. A used by surveyors to de- frequency). compass termine a suitable location for a trans- Model 1130 -S comes complete with tubes, test leads, carrying handle, instructions. mitter. Size 12" x 9" x 61_ ". Shipping weight 15 pounds. Our net price $11'85 20. When Pa sent Willie out to buy a The New Model 1180 -S radio "fan" magazine, he spanked the kid for bringing back a. Radio Guide. SET -TESTER b. Broadcasting. c. Radio Stars. A complete testing d. Radio Mirror. one laboratory all in Works on 90 -120 volts 60 unit. Tests all tubes, cycles A.C. Tests all 4, reads A.C. volts, D.C. 5, 6, 7 and 7L and octal 21. Being the 13th letter of the alphabet, volts, A.C. current. base tubes, including dl- M may be unlucky for you in this one, D.C. current, High odes. Tests by the well but try to tell what the m stands for in Resistance, Low Re- established emission method for tube the following radio abbreviations. sistance, High Capa- quality. directly read on the a. me. city. Low Capacity, GOOD 7 BAD scale of b. suif. Decibel, Inductance, the meter. Affords sep- and Watts. Comes arate neon test for leak- c. oua. housed in sturdy black age and shorts between d. nimf. case with sloping elements. Complete A.C. e. set. pan- Voltage el. and and D.C. and for rapid sim- Current Ranges. D.C. f. mh. ple measurements. Voltage: 0 -15, 0 -150. 0 -750 volts. A.C. Voltage: 0 -15, 0 -150, 0 -750 volts. 22. In a transformer coupled audio fre- Model 1180 -S complete D.C. Current: 0 -1. 0 -15, quency amplifier, a pulsating direct current with test leads, tabu- 0 -150, 0 -759 ma. A.C. is fed through the primary of the audio lar charts, instruc- Current: 0 -15, 0 -150, tions, and tabular 0 -750 ma. 2 Resistance frequency amplifying transformer, with the data for every known Ranges. 0 -500 ohms, result that the secondary produces type receiving tube 500 -5 megohms. High and Low Capacity a. A higher voltage pulsating direct cur- and many Scales. transmit- .0003 to 1 mfd. and .05 rent. ting tubes. Shipping to 200 mfd. 3 Decibel b. A higher voltage non -pulsating direct weight 18 pounds Ranges. -10 to +19. -10 Only to +38, -l0 to +53. current. Inductance: 1 to 700 c. A higher voltage alternating current. s17.85 Henries. watts: Based d. A higher amperage pulsating direct 6mw at 0 D.B. in 500 sshms .006000 to 600 current. Portable Cover e. A higher amperage non -pulsating di- 95c extra rect current. 136 LIBERTY ST., Dept. S.W. f. A higher amperage alternating current. SUPERIOR INSTRUMENTS CO., NEW YORK, N. Y. STRAIGNT-LINE STWUGNTnt[ MAMMY-UNg6 CAWICITYp WAVEIENGTN^ FREWENCYp UNIDIRECTIONAL DYNAMIC J D9T 4 BACK No Pickup 4 FRONT Full Coverage VOLUME INCREASED by Reducing Feedback 23. If you oere designing a nr.dern con- D9T, List $37.50, High Imp., broadcast receiver, the type of tuning 25' Cable. denser you would be most likely to employ D9, List $35.00, Low Imp., 25' is Cable. a. Straight line capacity. Write for Catalogue No. 29 development b. Straight line wavelength. Newest Manufacturers full line Dynamic. Crystal. C. Straight line frequency. in Electrolytic Capacitors and Carbon Microphones and Stands. d. Modified straight line capacity. Catalog upon request AMERICAN MICROPHONE CO., I.e. e. Modified line length. 1915 Western Ave.. Los Angeles. Calif. straight wave laeeadway, New Yert. So. SOLAR MFG. CORP. MAN f. Modified straight line frequency.

490 Please say you saw it in RADIO & TELEVISION RADIO & TELEVISION

www.americanradiohistory.com 24. A strain type insulator is so-called because a. It can stand high electrical strain. b. It strains out unwanted stations. c. It can stand high mechanical strain. d. It puts an awful strain on t! :r pocket- ell,711)14finFa4t book. 25. Even though you may not believe it, SEND FOR ALLIED'S ma- an interference generator is most used 'no 57pá%/C Is/ a. To drown out Russian programs in 180 Page 1939 CATALOG Germany and vice versa. b. To test "noise -free" antenna installa- kte:Wtti tions. I 62 NEW 1939 c. To test shielding of a set. LOW PRICES! SETS AT AMAZINGLY d. No such device is commercially pro- new sensational duced. DEALERS! -see the (Answers on page 512) Knight Radios in ALLIED'S for every purse and purpose-- 62 models new beauty, finer advanced features, new lcw tone, better performance -at Sets from 4 to 16 Ultra Short Waves prices. Tuning; nwe3a`Tin} y with Push -Button new AC, 11/2 Volt battery sets; and Television Knights," Volt and auto models. AC -DC, 6 Volt, 32 line of see the most extensive Dr. G. W. Pickard Also, phonographs, BACKED BY ALLIED'S phono -radio combinations, priced (Continued from. page 453) and record players in radio -all IRONCLAD GUARANTEE savings and All Knight Radios r covered to bring you greater ,\I- LIF:D'v ironel.n I '.. for the good and for your bigger by full. - :, :, ro on these frequencies, profits! Send coupon (eia.. -il gives Yuu sufficient reason that there is absolutely no ALLIED Catalog! other place for it in the whole radio spec- J THAT trum. There is another good reason why o A SET NEW VALUE STANDARDS SOUND MEN! it cannot go on lower frequencies, and this See tits rev- olm i, neu Knight is the fact that the lower frequencies in- Som.: PARTS! KITS! rams. 6 waive se 65 volve sky-waves, with consequent phtral SERVICEMEN !-All standard lines -- standard and luxe jobs de path transmission and a nasty mess of of test equipment- Rider's Chan - -for portable or alyst, Rural permanent Installations. Meter, New "ghost" images on the screen. The Federal etc -and over 14,- 30 watt Mobile Sys- 000 tems. Electric Guitar Communications Commission has tenta- exact duplicate Amplifier a n d replacement -and the mos, tively assigned, on an experimental basis parts. complete line of recording equipment In any catalan only, 19 television channels, each 6 mega- RADIO BUILD - 294 ERS!-We can sup- cycles wide and running from 44 to ply Free Parts megacycles, and this assignment seems wise. covering any kit de- Fastest sen low. scribed in this quanrices.1 highest It is becoming increasingly evident that lity -these are the any other magazine. watchwords which confronting television as a Write! have made ALLIED the problems New Push -Button F.quip- Radio's Lending Sup- public service are today economic rather ent- -makes your servic- ply [louse! and quicker. than technical. Before it can become a ing easier public service comparable with sound broad- Send for your tree ropy of the 1939 HAM GEAR! ALLIED Catalog today! You'll save casting, channel assignments must be made and profit with our low ernes and speedyD Y service. includesr ales EverythingE AM A TE : d, -, noun section asked It commercial rather than experimental, many l 'tl a,,,l \l'ove See Radio- thousands of money-saving.mon with high-grad,ewNation gear. groat e the new National NI'NC-44 -44 and SIO, Ilallirreftere -making Items for eve ry radio ' ,. m hundreds of miles of expensive coaxial cable man. "Diversity" and "a -In." Howard 4M0, 410 and It's roplouely illustrate d eo that . you ran sea what you buy; 0 430, and Sargent " '39 Streamliner" receivers.; must be laid for the distribution of network skillfully Indexed so that and the National COO Watt, Hall icrafters "11T," every Item is at your programs, and a large audience with com- and Pee -wee" transmitters. Write to us about our painless Time Payment Plan -the most eon- eve" 1pe. Send the mu- paratively expensive receivers must be built content non for Radio, Bn-Ing a ln Radio! Guide! RE E up. The programs themselves -the "daily Ì grind" type of programs as distinct from l=MMMMM CATAL06itaniiinio the occasional event" ALLIED RADIO CORP. "important -must Dept. 3-M -9 1 be made interesting in themselves as distinct 833 W. Jackson Blvd., Chicago. Ill. I from the novelty of the medium, or tele- Send me roar Free 1939 Catalog. I service most em- vision as a public will Name I phatically get off to a false start! Otherwise, Address as the novelty of seeing a picture on the screen wears off, and the audience becomes City Stato p. mom= pa really critical of program material, there . - -a. ------alum is the clanger that the receivers will soon begin to gather dust. A NEW SERVICE FOR OUR READERS! BETTER PERFORMANCE with must Be Sure to see the new FREE CATALOGS AND And it be constantly borne in mind INFORMATION Department on Page 511. BUD TRANSMITTING CHOKES that broadcasting in this country is solely supported by advertising, which pays for (1) effective choking on all amateur frequencies units composed of time and audience. (2) unusually low power Those myriads of us who listen from early BRUSH loss (3) uniformly built morning to late at night to sound broadcast- HIGH LEVELER SERIES of 5 lateral wound ta- ing, and who also go to the movies, know pered sections MICROPHONES very well that the ear can take much more Moderately priced to give punishment than the eye. Also, one can Range in price from you "THE BEST FOR hardly imagine a television program being LESS." Send 10c for Log used as a background for various home $22.50 to $32.50 Book SW 128 activities, bridge, for example. Taking these New Brush Headphones factors into consideration, it would seem that television programs would be a matter Write for your Brush catalog Today of two or three hours a day, rather than all THE BRUSH DEVELOPMENT COMPANY day and half the night, so unless its adver- 3326 PERKINS AVENUE tisers pay rather dearly for their limited CLEVELAND, OHIO BUD RADIO, INC. time, television stations will run in the red CLEVELAND, OHIO

for December, 1938 Please say you saw it in RADIO & TELEVISION 491

www.americanradiohistory.com OUR NEW SHORT WAVE LISTENER MODEL 3 -Tube A.C. Receiver (Continued froc) page 480) THE DOERLE MODEL D39 The power-supply is conventional, using a THE type 80 glass rectifier tube. The transformer OUTSTANDING provides 325 volts to each plate of the recti- VALUE FOR 1939 fier, 5 volts for the rectifier filament and Model D39 designed to have 6.3 volts for the filaments of the 6K7 and all the desirable features of our 6F6. larger models but at a price The within reach design is one developed in the labor- of all. atory of Wholesale Uses a 6k7g tube as screen Radio Service Company. grid tuned R.F. amplifier, a 6j7g It is available in kit form for the benefit of tube as tuned electron coupled constructors who prefer to "roll their own." screen grid regenerative detec- If the chassis supplied with the kit is used, tor, a 76g tube as a driver audio the mounting holes provided in it and the which is fed into the popular panel automatically determine the placement. and efficient 2516g beam power Keep the lead from the 6K7 grid terminal audio output tube which deliv- to the grid -leak and ers over two watts of undistort- condenser as short as ed audio power to the dynamic practical. speaker. Parts List A 25z6g tube is used as the 1 -Set 4-prong short wave coils (16 -217 meters) rectifier J 1 -Pair broadcast coils (190 -550 meters) and is fully capable of supplying the power requirements of the set. A type k92a tube is used as the ballast to drop the filament supply to the proper voltage. 1- .00014 mf. tuning condenser Separate 1- 25,000 ohm reg._neration control and switch controls for volume, tone, regeneration and R.F. gain are used. 2 -.5 mf. condensers A headphone jack is incorporated to permit the use of phones when desired which 3 -.01 mf. condensers automatically cuts off the speaker when phones are plugged in. 1 -10 mf. condenser A 1 -30 carefully designed circuit is used so as to Sold complete ready to -3 mmf. trimmer condenser give maximum efficiency and output. The built -in use nothing else to buy Ç 1 -Power transformer 325 -0 -323 V., 6.3 V.. 5.0 V. power supply is well filtered to eliminate hum. with all tubes and coils 1 2-Octal sockets Filter networks are incorporated in the audio 9 to 600 meters wired J 2-4 -prong sockets and tested 1- Panel, punched and drilled, 7" x 10" amplifiers and a tuneable hum filter removes all 1- Chassis punched and drilled traces of this condition common in many short All parts needed to 1 -Knob wave sets. Operates from regular 110 volt house build and wire but less 1 -Dial, vernier type current. Covers from 9 to 600 meters with no tubes, with all coils, $1495 1- "Ant. -Gnd." binding post strip cabinet, chassis and dia- 1-R.F. choke, 2.5 mh. skips which includes the standard broadcast band May be obtained and all wave bands gram. in battery 1 -A.C. line cord and plug short exceptt the amateur model or 220 volt model at same 2 w. resistors, _00,000 ohms 5 meter band. Send stamp for circular D39. -1 prices for portable or foreign use. 1 -% w. resistor, 300.000 ohms 1 -54 w. resistor, 2 meg. SEND 10C FOR OUR NEW CATALOG containing CIR('UIT DIAGRAMS, and 1 w. resistor, 250,000 ohms FLASH! complete information on over 25 different types of short wave receivers and transmitters 1 -2- w. resistor, 500 ohms from 82.50 and up. This catalog Is chock full of schematic and picture diagrams, hook ups and short 1- Dynamic speaker, 2500 ohm field, with output wave information. A book in itself. Well worth the dime, which will be refunded with your first order. transformer. 3 -Tubes (6K7, 6F6, 80) OSCAR B. 68 Coil Data KUSTERMAN New York CDept:12 Meters Grid Coll Tickler 10 -20 49 T. No. 22 D.S.C. 4 T. No. 31 D.S.C. (Spaced 6 '. per inch) (Close- wound) 20 -40 10% T. No. 22 D.S.C. 6 T. No. 31 D.R.C. (Spaced 12 T. per inch) (Close- wound) 40 -80 22% T. Nc. 22 D.S.C. í T. No. 31 D.S.C. (Spaced 16 T. per inch) (Close- wound) 100 -245 67 T. No. 228 D.S.C. 22 T. No. 28 D.S.C. Your Inquiries Invited (close- wound) (Close-wound) SPRAGUE 230570 12 banks. 8 T. each* 32 T. No. 36 D.S.C. When you need amateur equipment it No. 32 D.S.C. (Close- wound) ATOMS is to your advantage to write to Bob Form dia. 1l ". Tuning Condenser .00014 mf. Optional coil is 1 layer, 126 T. No. 28 S.S.C., Close - ZfAtteit Ati4eti oé {ill " Henry, W9ARA. You get personal at- wound. tention; terms financed by myself so you buy with less cost and more con- 25 Watt Xmitter Kit DUAL COMBINATIONS venience; fair trade -in value for your * equipment; Conlinl.cd ¡rum page 480) OR SINGLES ten day trial of all receivers; and my cooperation in every way the crystal stops oscillating, which will be * SMALLEST SIZES ON THE to see that you are 100% satisfied. No indicated by the failure of the neon tube to MARKET wonder Bob Henry's customers are glow. By decreasing the capacity of C -2, boosters. You will be too. For the new- the transmitter will function again and C -2 ALL WORKING * VOLTAGES est equipment, the latest information should be decreased until the set keys nor- and technical help: mally, as noted UNCONDITIONALLY GUARAN- by listening to the signal * in a receiver or a monitor. After this is TEED AGAINST BLOWUPS WRITE TO: done, it may be necessary to readjust C -1 BOB HENRY, slightly to compensate for the antenna. PREVENTS * LOW LEAKAGE BUTLER, MISSOURI The midget can be used as an exciter by OVERHEATING connecting a wire from the antenna post to Compare Bob Henry's Terms with Others the grid of the following stage. QUICK BUILD-UP * - Down 12 1r HIGH SURGE VOLTAGE Model and Cash Pay - Pas Receiver Price ment ment= FOOL -PROOF The NEW NC-44 $49.50 $9.90 $3.49 NC8OX and NC8IX 99.00 19.80 6.99 IN BRIEF ... recommended universally for replace- Improved NCIOIX 129.00 25.80 9.11 ments ... especially where The NEW NCIOOA 120.00 24.00 8.48 space is at a premium or RME-70 138.60 27.72 9.79 where you need a really reliable condenser at a Sky Champion 49.50 9.90 3.49 ROCK BOTTOM Sky Challenger II 77.00 15.40 5.44 PRICE. Super Skyrider 99.00 19.80 6.99 Also Super Pro, HRO, PRIS, Busting 9, Sar- A typical ATOM gants, others. value -8 -8 mid. 450 Similar terms on Harvey, Hallicefter, Na- volt l' diem. 216" tional, RCA, RME, Temco transmitters and long, list only $1.00 National, Thorderson, U.T.C., Utah, Stancor kits. Special Department for Export Orders

6.3vÇ SPRAGUE x HENRY RADIO SHOP LI. COIL FOR PRODUCTS CO. (16N0.8 .40 ORRM 27) WOUND 211 North Main Street Butler, Missouri North Adorns, Moss. Hook -up of Eagle Xmitter

492 Please say you saw it in RADIO & TELEVISION RADIO & TELEVISION

www.americanradiohistory.com New I lAM Licenses COMPILED FROM THE LATEST REI ttRDS OF THE FEDERAL COMMUNICATIONS COM MISSION

THERE are now nearly 50,000 licensed radio amateurs in this country. And hundreds of new amateurs are being licensed every month. Heretofore no publication has listed the name. and addresses of the new licensees as issued. RADIO & TELEVISION Magazine now provides this unique service, and will publish a list of newcomers in every issue. Check the names carefully so that you will be able to get in touch, not only with those amateurs in your neighborhood and vicinity, but also those distant amateurs whom you wish to contact either by mail or by radio. The first list contains 275 names of newly licensed amateurs.

K6QJS Leo A. St. Dennis, Morse Field, Naalehu, W2LQA Charles Melville, 226 E. 7th St., Plainfield, Hawaii, N. J. KitQLB Bernard P. Showalter, 250 S. Hotel, Hono- W2LQB Robert F. Wilhelm, 35 Lincoln Pl., Brooklyn, lulu, T. H. N. Y. K6QLG Henry D. Kalehuawehe, Vineyard St-, Wei - W2LQC Charles F. Herman, 30 -12 94th St., Jackson luku, T. H. Heights, N. Y. K7CNJ Charles B. Michael, Quinhagak, Alaska. W3BDR Gerald S. O'Connor, 3600 Halderman Ave.. WICGL Robert Nils Eichorn, 32 Lamper Hill Rd., Brertwood, Md. Auburn, Mass. W3BNI Elmer Brintliff, 718 Fillmore St., Riverside WIDEU Henry Dudley Minich, 465 Main St.. Mel- N. J. rose. Mass. W3HSW James A. Mallory, Va mi. south of Mc- WILOK John B. McGowan. 66 Bedford Rd.. Wo- Lean, Va. burn, Mass. W3HSZ Frank J. Ritter, 2448 S. Bouvier St., Phila. WILOL Henry A. Sawinski, 15 Warren St., Taunton. Pa. Mass. W3HTA Robert Geo. Hoffecker, R.F.D. I, Newark, WILOM George Kersherbaum, 1100 Albany Ave., Del. Hartford, Corn. W3HTB Melvin J. Keydash, 704 Ramsay, Baltimore WILON Charles W. Knight. 41 Ralph, Springfield, Md. Mass. W3HTC Franklin M. Stretto-, R.F.D. 7, South Rich - WILOO Murray E. Hall, 2 Cliff St.. Saugus. Mass. pond, Va. WILOP Julius L. Galinski, 7 Clay, Hartford. Corr. W3HTF Herman Lukoff, 2853 N. 22rd St., Phyla., Pa WILOQ Walter E. Tannas, 18 Windsor Rd., Somer- W3HTG Wm. M. Meloney, 18 S. Harrisburg, Atlan. ville, Mass. tic City, N. J. WILOR Franck T. Wittmann, 124 Grove St., Mel- W3HTI Paul V. Simpson, 21 Osborne, Phila., Pa. rose, Mass. W3HTJ Frank J. Bi¡oczyk, 91 Bruarig Ave., Trenton, I 7 St., N. J. RC WILOS George C. Wright, South Mai- Sharon. Mass. W3HTK Raymond L. Bocland, 3285 16th St. N. E., Imitative -Resourcefulness - Coopeahor D. WILOT Newton Stephen, 12 Howitt Rd., Boston, Washington, C. Io advance the wants Mass. W3HTL Norman E. Battorff, 28 Cumberland. of the indus y WILOU Raleigh Martin, Jr., 37 Russ Lane, Bristol, Trenton, N. J. Conn. W3HTM Carl F. Clauss, 2511 W. Firth St., Phila., WILOV Basil L. Wright, 5 Shelby, East Boston, Pa. Mass. W3HTN Harold R. Woodyard, 3235 Wellington St. TYPE WI LOW Victor H. Zirninski, 182 Marble St., Athol, Phila., Pa. Mass. W3HTO Charles G. Crider, Jr.. 28 N. 21st St BT WILOX Fredrick H. Tabor, Oyster Harbors, Oster - Camp Hill, Pa. ville, Mass. W3HTR Albert C. Faust, 32 W. Main St., Shireman- WILOY Francis A. Webb, Old Mill Road, Oster- stown, Pa. . I ville, Mass. W3HTS Charles M. Dihbell, 1810 -12 Tilgham St -, .ttq WILOZ Carl P. Rounds, 17 Oakland St., Auburn, Allentown, Pa. Maine. W3HTT James T. Lesher, 630 Mauch Chunk, Easton, WILPA John Sckuton, 71 Davo Ave., Auburn. Pa. Maine. W3HTU De Forest L. Trautman, Jr., 933 Corre" ESISTORS WILPC Geo. K. Boutwell, Lupinwood, Greenfield, Ave., Drexel Hill, Pa. Mass. W3HTV James R. Dale, Jr., 314 42nd St -, Newpc- Wherever radio is used WILPE Nickolas A. Chakos, 215 Saratoga, East News, Va. Boston. Mass. W3KS Louis E. Kearney, 4046 Maywood St Phila. throughout the world -there you WILPF Carroll M. Callamore, 116 Andrews St., Pa- will find IRC Insulated Metallized Lowell, Mass. W3MY Melville W. Ghen, 1410 Dennisto -. Pi's Resistors. WILPG Bryant E. Richardson, 160th Co. C.C.C., burgh, Pa. Greenville, Maine. W4AIK Leslie B. Stanton, 916 Spruce St., Gesde- No other resistors offer such WILPH Willard E. Barnett, 20 Woodland Pl., Hyde Ala. amazing protection against all Park, Mass. W4FQQ Kenneth Patterson, 47 Ave. "A," Oius kinds of moist. hot or humid WILPM Wm. W. Fairbanks, Hartford, Canyville, Fla. Mass. W4FQR Winborn L. Metcalfe, 5805 Central Ave. atmospheric conditions. No other WILPN John E. Callry, 486 School, Putnam, Conn. Tampa, Fla. resistors offer so much real qual- WILPT Andrews G. Moore, Airport, St. Johnsbury, W4FQ5 Walter H. Sturdivant, R.F.D. 8, Atlanta, Go. ity in every mechanical and elec- Vt. W4FQT William L. Townsley, 324 N. Willett St. WIMXU John P. Tyskewicz. 19 Morris, Hartford, Memphis, Tenn. trical characteristic. Con, W4FQV Nelson D. Large, 936 Sycamore St., Rock. W2BLQ Selwyn J. Slack, 188 Everett Pl., Englewood. Mount, N. C. PLAY SAFE! N. J. W4FQW Lawrence Won. Barrett, 702 Hicks St. Remember: IRC Insulated W2CRJ Charles E. Similey, 249 Ampere Parkway, Waycross, Ga. Metallized Resistors are both Bloomfield, N. J. W4FQX Edward T. Blackman, 2955 Minoual Drive W2EIA Herbert C. Cook, Lyan St. & Blossom Rd., Decatur, Ga. color coded and imprinted with Valley Stream, L. I., N. Y. W4FQY John McJunkins Brackett, 257 S. Jefferso' wattage rating and value for W2EJY Geo. E. Stephenson, 59 Roosevelt Ave., St., Mobile, Ala. your convenience. Sold by lead- Roosevelt. N. Y. W4FQZ Calvin S. Bryant, 809 E. Main St., Avon W2GV A Leland A. Drury, 24 Furman Ave -, Brook- Park, Fla. ing jobbers in all needed ranges lyn, N. Y. W4FRA Robert H. Sturivent, Jr., R.F.D. 8, Intersec in VI, 1 and 2 watt sizes. Use W2IAE Anthony A. Chizmadia, 107 Washington St., tion of Balton & Simpson Rds., Atlanta Perth Amboy, N. J. them on every service replace- W2KM Max J. Weiner, 117 Harrison Ave., Has- W4FRC Union G. Knight, 304 Isabel St., Greens ment job. Play safe by giving brouck Heights. N. J. boro, N. C. your customers the best! W2LPO Sidney F. Curtis, 145.25 156th St., Jamaica, W4FRD Lennox K. Ingram, 314 N. Second St.. Wi' L. I., N. Y. mingtoe, N. C. W2LPP Robert H. Kraft, 31 W. John St., Hicksville, W4FRE Claire Alvin Kennedy, Jr 1059 15 Ave. S. N. Y. St. Petersburg, Fla. "Theyy tay Put W2LPQ Percy Laster, 1050 Hoe Ave., N. Y. C. W4FRF Hilton E. Hightower. Damascus, Ga. W2LPR Alfred F. Sprague, le Jamaica Blvd., Carle W4FRG John J. Glidwell, Jr.. 3945 St. John, Jack- Place, N. Y. sonville, Fla. W2LPS Merritt L, MacKnight, 961 Palisade Ave., W4FRH Robert W. Frarklir, R.F.D, 1. Swarnanoa, North Bergen, N. J. N. C. Seymour INTERNATIONAL WILPT Levine, 422 Crown St., Brooklyn. W4FRL Arthur S. Fish, 337 S. W. 14th Ave., Miami, N. Y. Fla. W2LPU Wm. E. Talbert, Jr., 45 W. 110th St., W4MJ Livingstone R. Weyer, 806 E. 40th St., RESISTANCE COMPANY N. Y. C. Savannah, Ga. W2LPV Frederick Sprick, 10 Michigan, Paterson, W4PX Wm. Marcus Jones, Route 5, Jacksonville, 401 N. Broad St.. Philadelphia. Pa. N. J. Fla. Io Canada, 187 Duchess St.. Toronto. Ont. W2LPW Vincent J. Reavely, 244 Atlantic Ave., W5ADL Wm. H. Scott. Jr., Marks, Miss. Oceanside, N. Y. (Continued ou following page) for December, 1938 Please say you saw it in RADIO & TELEVISION 493

www.americanradiohistory.com New HAM Licenses All about the (Continued from preceding page) W5BIP Herbert Tex Wiley, 2 mi. south of Paris, SHORT WAVE LEAGUE Texas. WSBKJ Kyle Johnson, Johnson Ranch, Castolon, Texas. NOW -TWO TERMINAL W5CZT Earl G. Coston, 822 N. Asbury, Bethany, A FEW WORDS AS TO THE PURPOSE Okla. OF THE LEAGUE W5HKO James Edwin Ogle, Broken Bow, Okla. RADIO SUPPLY HOUSES W5HKP Joseph J. Zammit, 4779 St. Roth, New The SHORT WAVE LEAGUE was Orleans, La. founded in 1930. Honorary Directors are as IN NEW YORK W5HKQ James B. Shelton, Waterproof, La. follows: CITY! WSHKR Bryan Cowan, 204 S. Market, Brenham, Dr. Lee de Forest. John L. Reinartz, D. Texas. E. Replogle, Hollis Baird, E. T. Somerset, NEW STORE AT 68 WEST 45 ST. W5HKS Robert C. Culpepper, St. Joseph, La. Baron Manfred von Ardenne, Hugo Gerns- W5HKT Luther N. Davis Jr., 301 S. 15th Ave., back, Executive Secretary. CONVENIENT to MIDTOWN N.Y,! Hattiesburg, bliss. W5HKU Lyndon Erroll Dawson, 212 St., The SHORT WAVE LEAGUE is a scien- Both Stores Completely Stocked with Greer tific membership organization for the pro- Everything in Radio from Nuts and Haynesville, La. W5HKV Franklyn H. Dutton, near Covington, St. motion of the short wave art. There are Bolts to Complete Transmitters- no dues, no fees, no initiations, in connec- at Lowest Prices! Tammany, La. with WSHKW Silas M. Richie, 3018 Wilkinson, Ft. Worth, tion the LEAGUE. No one makes any New York, N. Y., Nov. 15- On Decem- Texas. money from it; no one derives any salary. has ber 1st, 1938, the Terminal Radio Corp. WSHKX John Wm. Midkiff, 250 Magnolia, Hot The only income which the LEAGUE is opens another radio supply house at 68 from its short wave essentials. A pamphlet Springs, Ark. setting West 45 Street, New York. Two well - W5HKZ Thomas Henry Morrell, 2709 Dodson Ave., forth the LEAGUE'S numerous as- equipped, easily accessible TERMINAL Ft. Smith, Ark. pirations and purposes will be sent to any- radio supply houses, one at the down- one on receipt of a 3c stamp to cover WSHLB Harry B. Smith 326 5. W. 23rd St., Okla- postage. town Hudson Terminal and the new homa City, Okla. store just a short distance from mid- W5HLC Teddy LaVerne Van Pelt, 228 N. Union, town Times Square, now serve N.Y.! Shawnee, Okla. FREE MEMBERSHIP CERTIFICATE Both stores are open until 8:00 P.M. W5HLD Robert A. Wells, 504 W. Indiana, Enid, every evening. Okla. As soon as you are enrolled as a member, a Mail orders are intelligently handled, W5HLE Lee V. Wolfinger, 24th 8 Elizabeth, Mus- beautiful certificate with the I.EAOI'ES seal will accurately filled and promptly shipped. kogee, Okla. be sent to you, provided 10e In stamps or coin Is Even our customers in far -off countries, W51-ILF Dickson E. Nuckols, 1007 Olive St., Texar- sent for mailing charges. who've never seen us and whom we've kana, Texas. Members are entitled to preferential discounts never seen, know well of our fair deal- W5HLG Lee W. Wall, 2030 Wash St., Amarillo, when buying radio merchandise from numerous firms ings and dej endable service. Texas. who have agreed to allow lower prices to all SHORT WAVE LEAGUE members. Cable Address: TERMRADIO WSHLH John D. Tallant, Compromise St., Kinner, La. WSHLI Lena E. Kay, 1286 Victoria, Beaumont, Texas. W51-ILJ Thomas A. Jennings, Vance, Miss. W5HLK Clark A. Perkins, 402 E. 8th St., Del Rio, Texas. W5HLL Ralph R. Rush, 905 D. St., Lawton, Okla. W5HLM Paul V. Fohrman, 1909 N. J., Ft. Smith, Ark. W5HLN Wm. M. Adkissan, 602 Parkview St., Dallas, $bOd).PaBr-rdIlr Texas. W5HLG Maurice G. Chemin, 400 Cincinnati St., El Paso, Texas. W5HLP David H. Weinstein, Oleander Hotel, Grand Isle, La. W5HLR Franklin B. Glenennine, 402 N. Broadway, Mt. Allen. Texas. W5HLS Verne!! E. Fleming, 208 N. Gregg, Big Spring, Texas. W5HLU Glen Tritt, Ponder, Texas. WSHLW Howard H. Hicks, Hotel Rex, Main St., Eudora, Ark. W5HLX Leonard B. Haggard, Industrial Add., Paw - huska, Okla. W5HLY John Porter Hardy, Tunica, Miss. WSHLZ Jack D. Giles, 822 State, Natchez, Miss. If you wish your n ngraved on the Free m WSHMA Shirley S. Allighi, U.S.U.C.R. Unit 3, 305 berahip certificate. as i llustrated above. please said lac to cover cost 80 CORTLAND! STREEI. NEW YORK. N Y N. Blvd., Baton Rouge, La. W5HMB Mark N. Terrell, Jr., 5619 Miller St., Dallas, WAVE ESSENTIALS LISTED IN OPPOSITE COLUMN SOLD ONLY TO SHORT Texas. WAVE LEAGUE MEMBERS W6CIJ John Court, 1101 Suffer St., San Francisco, Calif. They cannot be bought by anyone unless W6DLL Reginald 10584 he has already enrolled as one of the mem- Neelands, Ashton Ave., Los bers of the SHORT WAVE LEAGUE or signs RADIOC RAFTER Angeles, Calif. the blank belts' (which automatically enrolls W6GFI Roy R. M. Meadows, 8311/2 N. June, Holly- him as member. always provided that he Is a 2'1" VERNIER DIAL wood, Calif. short wave experimenter, short wave fan, radio engineer. radio nttdent, etc.). ROTARY BUFFED NICKEL W6HMW Hinman E. Bastran, 237 W. 82nd St., Los SILVER Angeles, Calif. Inasmuch as Ile LEAGUE is International, DISC. POSITIVE FRICTION W6KMZ Alfred B. Summers, 10 E. Fine St., Flag- It makes no difference whether you are Yeremoving staff, Ariz. citizen of the United States , any other coun- No freq. change hand try. 19íe LEADi -E Is open to all. from knob. as wit viain dials. W6NAY Massayoshi Harada, 1777 Euclid Ave., Ber- Net Price. less knob 90e keley, Calif. t t a^ Bakelite Knob 15e W6QIQ George A. Scott, 1229 28th St., San Diego, Catalog Free. Complete tine Calif. >dern. low -cost dials & knobs. W6QJF Donald A. Walker, 1020 W. 103rd St., Los Application for Membership N. E. RADIOCRAFTERS Angeles, Calif. 1156 COMMONWEALTH AVE. W6QJK Stanley H. Lai, 4053 Front St., San Diego, SHORT WAVE LEAGUE B OOKL I NE. Calif. SHORT WAVE LEAGUE 12.38 W6QJL Avery T. LeNoir, 32 West 2nd Ave., Mesa, 99.101 Hudson Street, New York, N. Y. Ariz. I, the undersigned. herewith desire to apply for W6QJN Robert B. McLaughlin, 3576 Beewick St., membership In the SHORT WAVE LEAGUE. In join- Los Angeles, Calif. ing the LEAGUE I understand that I am not assessed W6QJO Harry V. McMorris, 205 N. Kenmore Ave., for membership and that there are no dues and no fees CHASSIS CABINETS of any kind. I to abide by all the rules - Los Angeles, Calif. pledge myself and regulations of the SIIORT WAVE LEAGUE. PANELS & W6Q JP Floyd A. St. Louis, Route 5, Modesto, Calif. which rules you are to send to me on receipt of this CANS W6QJT Avery A. Ishmael, Jackson, Calif. application. STANDARD SIZES ON HAND W6 JU Robert F. Martin, 5264 Sumner Ave., Los I consider myself belonging to the following class Angeles, Calif. (put an X In rorr.ct spare): Short Wave Experimen- SPECIAL SIZES MADE TO ORDER ter O Short Wave Fan ID Radio Engineer W6QJW Howard F. Shepherd, Jr., 1220 S. Saint Student KORROL RADIO PRODUCTS CO. Andrews Pl., Los Angeles, Calif. I own the following radio equipment: Dept. S -12 W6QJX Verdie V. Keene, 124 S. Parish, Burbank, 350 Greenwich St. New York City Calif. Transmitting W6QJY Charles F. Denny, Willits, Calif. W6QJZ Thomas C. DuVall, 732 Euclid, Upland, Call Letters Calif. Receiving BE SURE TO READ A new booklet W6QKB Stephen H. Lazarien, Jr., 56 E. Harriet, covering h Altadena, t e Calif. Name theory and use W6QKC Richard L. Venturino, 6580 Christensen of quartz Lane, Hayward FREQUENCY CONTROL crystals. Only Calif. Address - %r Inc. (Canada W6QKD Lawrence E. Ruff, 274 Euclid Ave., Long 150. Buy it Beach, Calif. City and Stale QUARTZ CRY STALS Now! W6QKE George Edward Wann, 10591 Blythe, Los Angeles, Calif. Country W6QKF Donald Soo Hoo, 541 16th St., Oakland, I enclose ¡Oc for postage and handling for my Mem- Calif. bership Certil icate. (Continued on pape 497)

494 Please say you saw it in RADIO & TELEVISION RADIO & TELEVISION

www.americanradiohistory.com Accessories for Members of the Shooting Trouble on the Ham Transmitter SENSATIONALLY SHORT WAVE LEAGUE (Continued from page 468) Plate Meter Flickered with B- DIFFEREfVT/ enbe of the SNORT WAVE LEAGUE wants Identifytm your Return Open d siesbete prepared Suitableits el Iar tto stickers, IHtn a are m y cbuyn short. The transmitter consisted of a 6F6 os- way. acc uch a maps, globes, etc.. which the L eague offersrs only to members at special prices. Take cillator, 6L6 buffer or doubler and an H V advertisement. ESSENTIALS ARE SOLD ONLY tTO LEAGUE MEM ERS.E 100 amplifier. Upon turning, on the tilamen LEAGUE switch, the plate currents of the oscillatI SPRAYBERRY LETTERHEADS ovl A beautiful. official letterhead and doubler would flicker and vary as been designed for members. Radio The letterhead a wide scale, when the filaments li, Home Study is rrrspmnienee.Invaluable when it becomes necessarynary to deal with the ratio warmed, although the plate switch whirl mail order houses and Gives You Simplified Training radio manufacturers, marty simultaneously controlled the plate pow[ houses 'n offer members of the B negative LEAGUE preferential discount. to the final amplifier and the You Can UNDERSTAND The letterhead Is also absolutely essential returns to the exciter was off. Ovation t ó 'adwriting i ion sr eitheri here or abroad. It automatically Occasionally- the plate currents would and gives you a professional standing. stop, but then after a few seconds would SHORT WAVH CASH IN ON I A- continue as tlescribctl. The transmitter was I I. IT A O IT E letterheads, 50e IOU off tried. A -50c per 300 per shut and this procedure An ohmmeter was placed between the WORLD GLOBE cathode and ground to determine if there This In ortant essential ornamentglobe.` i an was a high resistance short or leak between In. in diameter. my fifteenfi color,, gm:ol possibly the B negative relay contacts or 11;'"In%`1, wagt' hat it r n lc qt washed. This lohe helps w the associated wiring. No indication was FREE BOOK intelligently Ing foreign stations., The lane in of solid walnut. ami observed hut this was not considered as a .age the ridmn of a nickel- like metal. Entire device conclusive test because of the possibility that a antlal made. and will You Learn by Doing Actual a Itrartemphasisin u, , part of the wiring was breaking down only station. emphasising workhoof opo.`I. when a voltage was actually set up. Next - Experiments with Neal Equipment D -Globe of whl An external source of 100 volts was ob- I Back You Pteopald 09C tained with the B negative grounded to the Up All the D-89e each transmitter chassis and the B positive at- Way with SHORT WAVE MAP OF THE WORLD tached to the cathode of the 6F6 and the Close Per- This beautiful map. measuring 10x26 in. to.s in 6L6 with a % watt neon bulb in series sonal At- is on a hung wave Don't Fail "under the) glass" on the table l io f thé!I. Inis,p with one of the legs. The B negative switch tention enthusiast. It contains a wealth rof'informatiol, surIt a to Investi- distances to nil parts of the world. political nature of the that controlled the relay which was con- country In which a broadcast is located, gate This the which the nected from cathode to ground to complete lliarts a New Home in differentlifferent of thehewworld ear the circuit. was left in an off position. When at a Training glance. the voltage was turned on, the same condi- F-RIIO ItT WAVE Map AGic Method. of the tVorld Prepaid í.e76 tion manifested itself, that is, the bulb flickered. The wiring in the transmitter WORLD RADIO MAP AND from cathode through the switch to ground I ACTUALLY SETeYOU UP' FOR A STATION FINDER was then disconnected from the socket. This BUSINESS OF YOUR OWN The (11,0,4 device of its kind pub - Berea the finest. most up-to-the- minute Radio ished. The w rlds m p o, heavy was Education available anywhere. Specially designed to l is divided Into 23 sections. would then prove whether the wiring whmile the rotary disc howl you give you intense, practical. quick training .. for immediately the exact timo In any at fault or not. Upon reapplication of the a money-making career In the fast moving Radio oreimi country. Invaluable In log- Industry. Even equips for your own business. foreign stations. Also gives voltage. the condition was found to still you ging11 letters assigned to all nations. Sloe 11-x22'. exist. This proved that the wiring was in TRAINING PREPARES YOU FOR JOBS AT The 6F6 was then removed C-Ra,lln Man of the good condition. $40. TO $60. PER WEEK world and Station Finder. from the socket, but still the condition per- Prepaid NO PREVIOUS EXPERIENCE NEEDED sisted. The 6L6 was removed and the con- My Training starts rigid at the beginning of Radio . . unfolds each subject in simplified. LEAGUE LAPEL BUTTON dition had disappeared. logical. understandable style. You easily learn all It was therefore concluded that the fila- about Television. Electronics. Police Itadio, SKID Ra- dio, Commercial Itadln Broadcasting . . . Radio ment of the 6L6 was periodically shorting Set Repair and Installation work, etc. C -25e each to the cathode when the filament was warm, YOU GET PROFESSIONAL EQUIPMENT causing an indication of plate cur - LEAGUE SEALS thereby TO HANDLE PROFITABLE SPARE.TIME .rent on both tubes in conformity with the SERVICE JOBS .... WHILE LEARNING swaying of the filament as it made contact l'usit+vely the finest equipment offered with any E -35e each with the cathode. Radio l'ourse Is delivered to you as a regular feature of SI'ItAY BERRY Training. You'll learn how to On the Trail of a "Shorted" Secondary Put these Testing Units and Tools to money- making This beautiful button is made In use through the valuable spare -time BUSINESel harde tel il four colors, red, and At the time of the breakdown, proper BUIWEIIS I supply. I show you bow and where tires tersi of annth ehin to get Radio Service jobs right in your own neigh- Iliameterr. Hy wearing this but- servicing instruments were not available borhood. You get Invaluable practical experience ton. other will ryeo0Yg- add to your bank account at the same you m ers to ti hence. handicapped the author in prov- profe air.iii Made In brotw, time. filled. not plated. Must ing that the part was at fault. G -15e for 25 ebodd stell to be appreciated. EXPERIMENTAL OUTFITS GIVEN These seals or stickers The circuit involved was the main power- Ìexecuted yin three E-- SHORT WAVE Sprayberry out lit s make ]Radio Study easy and ,d measure 11re supply for an -200 amplifier and the Interest log because you work out prod leal applica- LE.tGI'E l apel hon.. HF Inor, In diameterr.. wi`d tions of Itadio Principles with your mm hands. gummed on one .iode. Prepaid power supply for the modulator. One power by bers to affixto transformer was used to supply voltages The Sprayberry Course Is Sold Under an velopesetteprostais' EE -SHORT WAVE. LEAGUE Iron -Clad, Money -Back Agreement carda lapel button. the ono de- to both stages and consisted of three sepa- snd al scribed " Ins200 signifies that you enre a oid gra. rate windings. A humorous situation pres- SPECIAL SERVICEMAN'S COURSE ber of the SHORT ire rrepaiA WAVE. LEAGUE. sold ented itself when the transmitter was oper- I offer advanced Training for those all . in 25 lots or multiples Radio. Complete details of this advanced only. ated. Upon speaking into the microphone, 0-SHORT WAVE SHORT WAVE LEAGUE and fundamental Course, features. etc.. fu. I> LEAGUE the stain fuse would blow. This was indi- scribed in my new 48 -page FREE IRIIIK. .,.. Ì'nloail 99.101 Hudson St.. for your copy today. 15c New York. N. Y. cative of some trouble because the same size fuse had been used previously and was SHORT WAVE LEAGUE 12.3E modulation ISNTHISCOUPON 90.101 Hudson Street, New York. N. Y. of ample rating. Apparently on Gentlemen. (a Class "B" modulation system was used), O I member of the SHORT WAVE.. LEAGUE Ru x02 B16 FREE BOOK D Please send me for membership in the 'SHORT WAVE LEAGUE. the increased current drain would set up a Please following short wave essentials as high line current which was just sufficient SPRAYBERRY ACADEMY OF RADIO Hated Send menthe F. L. Sprayberry. President to melt the fuse. 145 -M University Place, N. W. Of course the main power transformer Washington, D. C. was immediately thought of as the cause. )'lease send ne FREE copy of "HOW TO MAKE and so the secondary connections to the MONEY IN RADIO ". fer which I enclose S herewith. transformer were disconnected preparatory Namo Age Name to testing it out. Address Address City State The normal procedure would be to test and of the three individual secondaries City State Country each with (Lail in un'rl ope fir paste r,upu" (111 postcard) S tamps in anyEdenminationeyRegi er. `cash and salmw:) (Continued on following page) a

for December, 1938 Peese say you saw it. in RADIO & TELEVISION 495

www.americanradiohistory.com Economical 25 -Watt TRANSMITTER Shooting Trouble on the An efficient, eco- Ham Transmitter CASH IN nomical transmitter, using the 6L6 (Continued front preceding page) metal tube. The ON YOUR SPARE TIME! kit is furnished an ohmmeter, and thus determine whether complete with es- there was a serious departure in resistance sential parts, fully from similar windings. 300 WAYS mounted on black crackled Bud Two secondary windings were rated to TO MAKE chassis. No drill- deliver 1000 volts and one winding 1500 All ing necessary. volts. The turns ratio for the 1000 volt . you rued is plier: MONEY and soldering iron. windings was 8.7 to 1 and for the 1500 volt ONLY ,?_. winding, 13 to 1. Knowing the turns ratio,

it would then be possible to 25c I 68 The FB25 calculate the - New EAGLE voltage at the primary when a 110 volt Per Copy ,( /PAGES COMPLETE KIT, READY TO WIRE 7 source was connected to any one of the We furnish a readywmmd plue- MAIL ORDER PLANS In roll for your particular l cud. secondaries. If the voltage obtained at the BRAND Your choice of IGe- Olr -40 or 211 95 primary deviated from the calculated value, TESTED MONEY MAKERS NEW meters. ACCESSORIES it would then be sufficient proof that part BOOK OLa Power Tube -sae. High BUSINESS SECRETS a0,000 WORDS Grade FEATURES Crystal and Hola1er- of that secondary was shorted. A 0 -150 A.C. in 1 Versatility Economy SCHEMES TEXT! u forf R a bands-suc Lea 2 band voltmeter was available and the line voltage SUCCESS In "CASH IN" Wiring fopiionall 112.00. Crystal I operation ywith o you get ALL Power Supply for FB25 or 25 watts of power measured, which proved to be 125 volts. The %ldlll I ll1 \\\ Easily Constructed. \' the real money- 5Z3 or 80 Tube for rans'er stepped down voltage at the primary when ¡'r Simple to Operate. An makers - dozens Power Supply 4VIlei IZ Ideal transmitter or Es. the line voltage was connected to a 1000 of profitable tested nnnall -.,, 25 volt secondary should be 1.43 With SOLD ON A mail order plans. volts. business for Duplex this in mind, the test was run and the MONEY -BACK - confidential GUARANTEE! secrets. dozens of prac- "b°t RECEIVER Work voltage obtained at the primary was 1.42 tical tested formulas, suc- volts as indicated on a 0 -3 volts A.C. volt- cessful tested s..hemes- actual experiences of men who have started on a shoestring EAGLE Minuteman meter that was connected across the pri- -with less than $10 capital. 2' "z-5 -10 METERS mary-. As this was very close to the cal- Amateur Band Receiver Buyers of This Book Tell Us- for Consistent culated value, it was agreed that that sec- reception . . . "Biggest value I've yet to see. Book is on the loudspeaker. ondary did not have any shorted turns. The worth at least a dollar." S. BUDA, B'klyn, N. Y. MINUTE MAN KIT test was then repeated on the other 1000 Your book is as good if not better Complete $475 than others selling at $1.00." with 3 volt winding, and this time the voltmeter GEoRce Banner, Montreal, Can. Coils indicated 1.55 volts, showing that a con- 2 Tub es 5125 "CASH IN is the best value I have yet 6C5a42 %.:,,.i''`ho`ti`.. siderable portion of the turns was shorted to see in the mail order field." WIRING 25 (short -circuited), thus lowering the turns LAWRENCE Fox, Brooklyn, N. Y. WIRING E ratio "CASH IN" contains only tested ideas cover- OPTIONAL 'super regenerate, receiver aknown, and increasing the voltage by a rela- glass The ing every type of full -or spare -time enterprise last word in performance andand simplisimplicity design. lt tive amount. business ventures. 1st 2ts to 10 meter ever offered to the ama- -it's a "masterpiece?' in teur at such ridiculously price. No license necessarytees This winding was used for the modulator to operatel l it. 25 CENTS per copy. Sent POSTPAID anywhere MAIL ORDERS FILLED PROMPTLY. power -supply and when the current through upon receipt of 25 cents U.S. stamps or coin. 52.00 Deposit. Check or Money Order, Balance C.O.D. the winding increased. a heavy parasitic load was reflected back into the primary, NATIONAL PLANS INSTITUTE EAGLE RADIO CO. 246 -T FIFTH AVENUE NEW YORK, N. Y. 84 CORTLANDT ST., DEPT. 1. NEW YORK CITY thus blowing the fuse. LAMP MODERNM DESKSK FRE E Is Yours Absolutely & TELEVISION Subscription to RADIO THIS With a Year's SHADE TILTS UP AND JUST THINK OF 1T -you can get absolutely FREE, the beautiful desk lamp shown DOWN at the left. This attractive desk lamp is suitable for home, desk, den, office, laboratory, studio or workshop. It is sent to you by the publishers with their compliments for a one -year subscription to RADIO & TELEVISION. Look at the many fine features which this handsome desk lamp has. Read the list below. LOOK AT THESE FEATURES! O Constructed of metal with attractive O Stands 13" high and has 10 " metal bronze finish. shade. O Scientifically constructed to give glare- O 5 -foot rubber insulated cord and plug. less, diffused light. o Helmet -type shade can be tilted to any O Constructed to last for many years. convenient angle. Clip Coupon Today and Mail! r -k - RADIO & TELEVISION, 99 HUDSON ST., NEW YORK, N. Y.

Send lient l r a your subscription today to RADIO & TELEVISION for One lenten: Fnelned w i l find v i t L . l - e a f $2.511 for whielt enter my Year (12 issues) and receive subscription to RADIO A Tt.i.F.VISION e for One Year 112 es). Send me absolutely FREE one of these truly promptly my FREE DESK LAMP. Consola and foreign 53.25.1 InU.u S. add 25c remarkable desk lamps. New subscribers are accepted or you may extend additional to shipping charges of lamp. your present subscription another twelve months under this offer. Mail ( ) NEW SUBSCRIBER ( ) EXTEND PRESENT SUBSCRIPTION your remittance of $2.50 (Plus 25c for shipping charges on lamp) to the publishers of RADIO & TELEVISION. (Canada and foreign $8.25) Name You will promptly receive your FREE DESK LAMP by return mail. Use the coupon at the right to order your subscription. Address

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496 Please say you saw it in RADIO & TELEVISION RADIO & TELEVISION

www.americanradiohistory.com New HAM Licenses (Continued from paye 494) For TOUGH ASSIGNMENTS Investigate W6QKI Delos Pendleton Trim, 4205 Kansas, San This Set Diego, Calif. W6QKJ Ralph J. Myers, 2017 25th St., Sacramento, Model 51 Features Calif. Regeneraticc Input, all Input Rands lt.F. Control W6QKK Peter James Neimo, 990 Scott, San Diego, Manual Volume or AVC Calif. BIgh 10/20 Meter Efficiency 'l' lie Control W6QKL Aaron S. Aaronian, Peach Ave. & U. S. Push -Pull Audio Highway No. 99, Fresno Calif. 10 New Type Glass 'runes Jensen Speaker W6QKM Donald D. Wells, 201 S. Linden Drive, ` Equivalent Performance s. C. -D.t'. Circuit Beverly Hills, Calif. 13 'Pubes W6QKN Franklin W. Scott, 1024 N. Redington St., Pull Rate A.C. Isnlxntite Insulation heatmillcation Hanford, Calif. Shadow Tuning W6QKO Donald C. Miller, 270 E. McFarlane St., Both loser l.lnes Ventura, Calif. Iron Corr I.F. 1'i ll rl ed hand Spread W6QKQ Ray. W. Bailey, 977 Santa Ross, San Luis Lifer lure Filter Con - Obispo, Calif. C. W. l'itdt Control densers. -no Elect roiyt ics IL F. W6QKR Wm. Barrett, 4521 Delongpre, and Det. Panel 'Shielded. Moisture -proof Los Angeles, Trimmers Bypasses Calif. Break- W6QKS Harry In Switch Insulated, Moisture. L. Blacker, 223 W. 3rd St., Long Headphone .lack Beach, Calif. moor Resistors W6QKT Ernest Beard, Ilth St., Montague, Calif. Model 51 Can "Take It" ALWAYS IN ALIGNMENT - Beautifully Perfect tracking between W6QKU Argus C. Fox, Jr., 519 Sacramento St., hunt, and of the finest materials. Engineered nits wit,, illator and detector rT. with the latest det'el°prooms ,n the art. trA nI ged, ensl- fixed trimming is °eMai nahte only In she Nevada City, Calif. 1ve selective,ti receiver that will give a sgood ta,rals ln,'v. Model 51 makesx possible perfect align- fit ment frequencies at all W6QKV Stephen A. Douglas, 26 Rock, Reno, of itselfself i location. limes because n' Nev. 'I 'Ohicommon I,,eloperated Individual h trimmers n It.F, inner work i mn, rial-tyue installations detector and W6QKW Robert maeur .stat ions Model 51 will give fist oatis- c rcults. The operator lias only o touch Carter, 1001 Bth Pl., Hermosa f.ct nn. Easy to operate. but with controls olio the panel these to assure himself at v time as to alignment. Beach, Calif. wherever desirable for an experienced operator. RE. xeme seectivity of regenerative R.F. stage. W6QKZ Warren H. I;F :NF:RATIVR INPCT having sensitivity n1 image re- to an I.F. s nge selectivity. makes panel Palmer, 2953 Long Beach Blvd., ice inn equal to 3 n 4 R.F. stages at the higher fn.. iming in,total ive °n this receiver. Long Quiet. stable. frequent,' Beach, Calif. .envies. practically free from A GO- GETTER FOR DX W6QLA William R. Porter, 412 Parton, hiss Regenerative input brings S. Santa level. Performance fihirtecommunication work equalolto nits. threugb those weak sag. Ana, Calif. that of any receiver. regardless of prise. lost i, the ' ud on m., w large. multi -tube W6QLC 'l'he ideal set for the 143 hunter. George M. Salammovich, 2101 /2 El Re- r Write f, r r° nplete data. do "do, Calif. W6QLE Shiko G. Tahara, 1609 S. Tamarind, Comp- Streamliner '39 MODEL 51 NET PRICES ton, Calif. A sensational value a communication receiver. Model 5I -AK. 9.3 to 330 meters, 110 s e het, covers 111 mters. illuminated dial. 157.00 W6QLF David Wm. Hart, 1324 Punta Gorda Ave., stages u 1.F.. tunnel trimmer. Boat Oscillator, AVC. rolls AC. DC net Santa Barbara, Calif. 4 tuning bands. Covers to 550 meters. lses Model 5I-MK. band switching, -no nluin1'i coils. 9.3 tu 3730 ureters. 110 00 W6QLH Chauncey E. Downey, 2451 Net volta - DC $175 Gunn Dr., Oak- l'rirc. 1 plete with tubes. sneaker $f AC net W J land, Calif. IIWCE, ready to go $33.90 Equals perburnuotee of receivers selling for many W7HCH Harold A. Norby, Route 2, Newberg, Pines the line. Oregon. E. M. SARGENT CO., 212 9fh St., Oakland, Calif. W7HCJ Ralph J. Farano, N. 4906 Lacey St., Spo- kane, Wash. W7HCK Ellison S. Mark, 703 4th Ave., East Kali- spell, Mont. W7HCL William A. Sourwine, Belton, Mo. W7HCM Wm. Samuel Moulton, 514 E. 6th, Tilla- DECIBEL METERS mook, Oregon. oSISTrAti. W7HCN Paul S. Thun, 915 E. 5th St., Tillamook, Larger dial opening Oregon. 4 gives more light on W7HCO Adam Wastradowski, 2804 E. 16th St., Van- F9)LET scale by" couver, Wash. W7HCP John Walker, Apt. 4, 1409 W. 4th Ave., Spokane, Wash. W7HCQ Richard M. Rogers, 2544 N. E. 48th Ave., Portland, Oregon. * 3" and 4" W7HCR Louis S. Soofield, 821 S. Dakota St., Butte, Sizes Stocked Mont, W7HCS George Emil Minich, 4411 29th St., Seattle, Wash. ,v Other Sizes Available W7HCU Wm. C. Boughton, 103 E. 54th St., Seattle, Wash. W7HCW Fred S. Winkleman, 1606 Ash Ave., Cot- * Round or tage Grove, Ore. Square W7HCY David B. Newman, 626 5th St., Astoria, Ore. W7HCZ Christian Melgard, Port Orchard, Wash. ,f Attractively W7HD8 Edwin M. Boden, 112 S. Albion, Burley, Priced Idaho. W7HPA Cifford R. Masters, R.R. I, Alice!, Ore. W8AKO Earl T. Denton, 4531/2 N. Chestnut St., Butler, Pa. W8ARY Lester S. Young, 46 Main St., Yorkville, \ N. Y. Model 321- A Decibel W8BZP Joseph N. Peckham, 24 Case Ave., Auburn, Meter N. Y. W8CDJ John N. Weever, 467 Cayuta Ave., Waver- 3" Instrument in New 00 1, N. Y. Style Molded Case .. W8FPK Allen G. Sanderson, 380 Elmhurst, Highland $12 Park, Mich. Standard range reads up 6 and down W8GIY Jim F. Correll, Camp Skeet, Oscoda, Mich, 10 W8GQP Ralph E. Grant, 2221 Benjamin, Saginaw, decibels, zero decibel at 1.73 volts, 500 \ Mich, ohm line, 6 milliwatts, standard damping W81OY Mitchell J. Soho, 2243 Spokane Ave., Car- rick, Pittsburgh Pa. furnished unless highly damped is WBSLP Arthur J. Odgers, Apt. 103, 610 Andrews St., specified. x N. E. Massillon, Ohio. W8SLQ Cecil P. Randall, 1113 W. Kalamazoo St., NEW CATALOG #161 Lansing, Mich. ALSO 4" MODELS W8SLR Hal Joe Shafer, 1112 Norwood, Toledo, Model 321 -3" Round $12.00 Ohio, JUST OFF THE PRESS W8SLU Clare C. Harroun, 3106 Caroline, Auburn Model 421-4" Square $13.17 Heights, Mich. W8SLV Walker Faussett, 710 E. Clinton St., Howell, May we send you a copy? Mich. Decibel Meter Kit -Model 150 Kit com- W8SLW Chester P. Rempinski, 6128 Comstock, plete with Decibel Meter, necessary multi- trou, De. CORNELL - DUBILIER Mich. pliers, switch and other accessories $20.00 W8SLX Louis H. Rose, St. Joseph Hall, University ELECTRIC CORPORATION of Dayton, Dayton, Ohio, tf' 1027 Hamilton Blvd., W8SLY Milton E. Kohl, 424 Brookside Drive, Dayton, THE TRIPLETT ELECTRICAL INSTRUMENT COMPANY So. Ohio. Plainfield, N. 1. 2812 HARMON DRIVE. BLUFFTON, OHIO W8SLZ Harold E. Knipe, 510 Brown St., Strouds- burg, Pa. W8SMA Lawrence R. Walsh, 407 Clinton St., Ham- COMP ETE DYNAMIC ilton Ohio. TESTING EVERYTHING IN RADIO! Direct. inock. W8SMC John Joseph Erhart, 844 Charlotte St., Cin- practical inittructien cinnati, Ohio. 1 COMM IMO FOI ION HBO IBM o.a ,.na. .c e, , W8SMG Fletcher H. Moore, 1148 Overlook Ave., .eaerae .. . .:w: sups,. Cincinnati re :.nambsa:, You .ñ ibná . ye.. Ohio. Know. F..o°I.s Ibis ~iN-aa: tG.tr r s WBSMI Lyman 50c i Ohl. ,s FREE lot . A. Goldsmith, 297 tit* R.ene.11r Maple St., Buf- er TODAY .,d., falo N. Y. epd I . dar a.N WRITE roo 61G NEW W8SMK Floyd La Verne CATALOG Draper, Route 3, Vassar, FREE WITH ANY C -B INSTRUMENT Mich. BURSTEIN-APPLEBEE (Continued on following page) Clough-Rrengle Co., CLic.go, ID., U. S. A. CO. 1012 -14 McGee St. o Kansas Gtr, Mo for December, 1938 Please say you saw it in RADIO 8 TELEVISION 497

www.americanradiohistory.com New HAM Licenses LOOK & BUY! (Contiued from preceding page) STOP, W8SMM Geo. R. Black, 482 Wyoming Ave., Wyom- Rockbottom Prices On Army and Navy and Surplus Merchandise ing, Pa. WBSMN Paul Wm. Euehler, 3610 Holies, Toledo, When prices are low we buy! They're low now -LOWER THAN THEY EVER WILL BE- Ohio. this sale. Most of the merchandise is new -never used; some of it reconditioned. Nelson N. Clark, Montello Park, Holland, hence refunded. W8SMO 100% satisfaction on each transaction or your money Mich. Read- ORDER FROM THIS PAGE. Use the convenient coupon below. Be sure to include sufficient W8SMQ Alban A. Michael, 145 Amity Rd., charges, else the order will be shipped express. charges ing, Ohio. extra remittance for parcel post Toledo, collect. Any excess will be refunded. C.O.D. shipments require a 20% deposit. If full WBSMR Frederick A. Mason, 27151/2 Albion, accompanies order deduct 2% discount. Send money order -certified check - Ohio. remittance Marshall, new U. S. stamps. No C.O.D. to foreign countries. W8SMS Harry A. Martin, 341 S. Linden, LIMITED QUICK SHIPMENTS ASSURED Mich. ORDER TODAY QUANTITIES W8SMT Albert Wismer, 4219 Station Ave., Ash - Ohio. SPEED UNIVERSAL MOTOR tabula, 1 H.P. UNIVERSAL MOTOR VARIABLE F. Krjscalla, 1294 Newport, Detroit, EDISON /60TH Ton 110 VOLTS. A.C. OR D.C. W8SMU Carl Made by Edison Electric Co. for Dictaphone maehines. b American Gramophone Can used volt Made for Dictaphone machines Mich. lines (any Ave., Belle- . or A.C. W8SMW Earnest A. Heu, 433 Forest A.C.). Double Go'diloli. Special lexcellenter shafcYt. 5riáth in. diem. Any trol permits variable speeds vue, Pa. Su iat - r Green - e with shaft extends from both WBSMX Louis A. Dimssi, 641 Highland Ave., eiede rheostat.hetnablet. Size x Measures Pa. Sigh, id overall.' of motor. burg, widesa 31iaa^ diem. ovemu. R.F.D. 4, Mo- Shp. Wt. aa4 lbs. Shp We. B3á lbs. WBSMY Howard G. Halbert, Jr., Va. ITEM NO. IO nongah, W. $2.25 ITEM NO. II St., Ann Your price $2.55 W8SMZ Allison F. Chillds, 435 Thompson Your Price ...... Arbor, Mi:h. W8SNJ Lynn E. Dahlstran, 1328 Poplar St., Flint, SPERRY GYROSCOPE LIQUID COMPASS WESTERN ELECTRIC BREAST MIKE Mich. Made for U.S. Signal Corns: si- ` aunt. W9AQW Chester Buchanan, 1/2 mile east of Logans- tive and accurate. Quick readings top: accurate read. microphone.mgwith with breast plate port, Ind. de from tag. an be for home i;road. St., St. Ieasilyngo ofgraduations through focus- casting or private m unicatioo W9ASC Herbert M. Sigman, 6409 Oleatha sing magnifying lens side of in- tams. la d plug. Shp Mo. strument. Complete with level sights t Ight.i Louis, and russet leather carrying case. Ex- Wc. 4 lbs. uiivatfetad W9EYE Ward D. McIntyre, 129 Lake St., Chadron, cellent for boats. boy scouts. camp - ITEM NO. 14 hikers, etc. A few turns of Your Price $2.45 Nebr. wirea around its case It bie W9KAG Eugene L. Cummings, 6091 E. 14th, Kansas Shp. Wt. 3 lbs. :Magnavox AntiNoise Microphone. galvanometer. also good for home broadcasting etc. City, Mo. ITEM NO. 12 $1.85 With cord and plug. Shp. Wt. 2 lbs. W9KBC Peter Laneioni, Co. 1693 C.C.C., Platte- Your Price ITEM NO. 15 $1.80 ville, Wis. Your Price W9KBG William M. Lee, 3824 Park Ave., Indianap- PORTABLE TELEGRAPH AND BUZZER olis, Ind. N. Rural, Chip- FIELD SETS NAVY PORTABLE SEARCHLIGHT W9KBI Stephen V. Marzycki, 104 W MILE RANGE pewa Fals, Wisc. SVcstertn Electric. Asywon- type 909 Cham- buy if only for Cast aluminum W9KBK John L. Morris, W. Washington, derful handlelboe parts it contains. New-t gla le 5 = dem.. Triâerwithg hc nd paign, Ill. been Good for operating. tilting and focussing lamp. never s and W9KBN Raymond P. Murray, 404 Mission St., St. code practising. signal. x -Ray Co. U.S. Mg. communications. etc. for Kans. high -fre. Navy. Measures 4^ deep x Mary's, Contains 2 -lone. 51,h^ diem. overall. Focal W9KCB Ernest C. Wolfe, 6310 Grant St., St. quency buzzer length Approximate. contacts, wterlelrlaph 1á Joseph Mo. key. telephone switches. Park, earphone. condensers. ;eOu W9KCD Harold P. Krauskopf, 2429 Weisser transformers etc.tc. pipe ppo.Complert Ft. Wayne, Ind. A 350 value easily. Corn. wooden case.ase. Excellent for camps. T. Hiles, 206 E. Empire, Blooming- barns. d out. W9KEQ Wm. driagramsoecnd instruc-tt indoor displays. ton, Ill. tions. Shp. Wt. 12 lbs. door and with either B W9KEX Helen S. Hain, 2209 Blake Blvd., Cedar 12 ppliedIt lamp. Shp. Wt. ITEM NO. 113 $5.45 14 lbs. Net 4 lbs.) Rapids, Iowa. Your Price .. M. Hassmann, 16 Sherman Pl., ITEM NO. 17 06.65 W9KFD Harold RIFLE SIGHT AND OBSERVERS' Your Price ....$6.65 Appleton, Wisc. PRISMATIC W9KFE Henry C. Frayer, 1058 Linden Ave., Wil- SCOPE mette, Ill. Made by Warner R W9KFJ Lane D. Coss, 1611 Pattie, Wichita, Kans. ser. Consists Of AIRCRAFT GENERATOR PROPELLER Louisville, St. matie ocular and c, automat- W9JFI Robert H. Overbeck, III lens 06 lowed. . Deslauriers acule with r is eo rouable Pitt°. STREAMLINE Louis, Mo. Operating peed 4.500 S. 58th St., 2 highly Wished Blade 1sti. Cm) W9JFO Norbert J. Niewiadomski,1749 bronze fr . .p.m. set in solid ati';e sweep a3^. All West All s, Wisc. ; aluminuma and bronze Park, ñi, metr ne, Complete with. W9JGJ Charles von Bohr Lau, 5331 Lake forh°e yardage nd indagt'- I ;.;:i :e - t, ,:.. housing. Savan1t. a ;'. streamlined housing Chicago, Ill. on Erag. Enfield. 1536,001 shown dotted,. Flt s Louis- and leather cas e. Shp. Wt. 4 lbs. Regular 0/160 shaft. Net weight W9JGT Everett Nelton Shinn, 3415 Larkwood, ITEM NO. I8 51/2 lbs. Shp. Wt. vtá ville, Ky. Your Price $8.95 lbs. Original cost S200. W9JHB Charles G. Sanner, 765 Alpine St., Dubuque, ITEM NO. 19 $5.25 Iowa. TAPE RECORDER Your Pries W9JHJ Jos. Dudley James, 817 Dearborn St., rrya Chicago, Ill. PAPER TAPE ADApparatus makes Duncan, 952 N. Lewis Ave., PULL record of W9JIl Donald D. GUIDES code and FLOODLIGHT Waukegan, Ill. Paper Made to U.S. Navy rigid Bernard P. Groll, 3415 Osage St., St. Angeideal ne for specification these tutdilly W9JIK constructed foodlighte Louis, No. teeacihing to t less than Hartley Starks, Main St., Har- groups. RadioRa men halavailablef their original price W9JIT Winston can easily adapt it to of S70.00 Brand new mer. din, Ky. hort - waive rivera chandlse, ever before used. 211 E. Jefferson, Kirk- for nest Pittsburgh floodlight type W9JKI Richard Kerr Moore, records of code FLC500. 16^ Durex lumi- wood, Mo. s`a`gs. Double pen flector. Floodlight Adams, Jefferson eons has double adjustments and W9JKV George W. Onken, 718 recordingrre`ording if two is weatherproof. Takes 300 City, Mo. Pens are open to 500 Watt Mogul base G. Matthews, 317 S. Kinlworth, Oak by battery and lamp. Measures lax 18" x W9JOZ Gilbert kledey while tape feeder 24^ overall. Shp. Wt. 55 Park, Ill. won di. Case made of solid is spring driven (hand lbs. W9JPB M. Eugene Walker, Trafalgar, Ind. brass on heavy iron base. Completely reconditioned. ITEM NO.21 $2(a70 obtained anywhere.) prig l cost I Less tape: easily Raymond Wee, 432 Pearl Ave., Fargo, Silo. Wt. 20 lbs. Your Prise .. W9JPM A. S85.00. N. D. 20 ITEM NO. $19.95 W9JPZ Florian E. Pijanowski, 2219 Whipple, Chi- Your Price ANTICAPACITY SWITCHES cago, Ill. W9JQH Ernest Jacob Vold, Main St., Tuttle, N. D. Electric. ARMY AIRCRAFT KEY Made by W9JT1 Joseph S. Szewzuk, 634 Second St., Hunt- solid oble throtVCate Army aircraft with terminals-equivalent to two ington, Ind. brJ.Eass transmitting key -pole. d o u hie -(h r o .c large heavy duty double W9JTK Austin Mosier, 1181/2 S. 4th St., Watseka, Ill. Well ac- switches. All contacts re of Shp. Platinum plate. Original price W9JTL Clyde L. Mock, 813 N. Morgan, Rush- tion-easy on the fist. Shp. Wt. 1 lb. Wt. 2 lbs. $3.50 euh. ville, Ind. ITEM NO. 22 ITEM NO. 23 $1.55 W9JUB Charles D. Earough, 1407 14th Ave., Cen- Yourour Price $1.90 Your Pricerice tral Citi, Nebr. NO CATALOG. ORDER FROM THIS PAGE. W9JWA Clyde C. Arntzen, Crescent City, 111, WE HAVE W9JWJ Joanna Locke Barnes, 724 N. Florissani Rd., B'way N.Y.C. Fergusoi, Mo. HUDSON SPECIALTIES 40 -T West W9JWK Grant F. Baurt, 1220 Putman Ave., Janes- ville, Wis. IT'S EASY TO ORDER -CLIP COUPON -MAIL NOW W9JWM Adin E. Randall, 1042 Main St., Eau Claire, r Wis. HUDSON SPECIALTIES CO., 40 -T, West Broadway. N. Y. C. 1238 W9JWR Bryan O. Pritt, 616 Cheyenne, Alliance, I hare circled below the numbers of the items I'm ordering. My full remittance of S (include shipping Nebr. is enclosed. W9JW5 Fred C. Bulmain, Jr., 2729 Winter St., Ft. charges) order C.O.D. for balance. (New U.S. stamps OR my deposit of S is enclosed. (20% required), ship Wayne, Ind. check or money order accepted.) W9JWT Reid H. Purrans, 2541 Summerdale, Chi- 23 Circle Item No. wanted: 10 II 12 14 15 16 17 18 19 20 21 22 cago, II. W9JWU Robert Wm. Will, 1441 7th St., So. Fargo, N. Name Address Dal. W9JWW Leslie F. Card, Harveyton, Ky. State W9JWX Albert Kurz, Gackle, N. D. City Frank H. Inderwie, 1601 Broadway, Kansas or money order; register letter if you send cash or stamps. W9JXH Send remittance by check, stamps i City, Mo.

RADIO & TELEVISION 498 Please say you saw it in RADIO & TELEVISION

www.americanradiohistory.com NEW RADIO APPARATUS Test Equipment Speeds Your Radio New Dual Electrolytics Education THE Minicar, line \I ETERS and test equipment are useful in of Solar condens- trouble shooting because they eliminate tht ers now includes a guesswork. They have the same value dual unit which ex- to tilt tends the capacitors amateur as surgical instruments have to a doctor. No amateur can actually know what takes place to practically all in a circuit unless he has the proper equipment commonly used to enable him to diagnose actual circuit conditions. values. It is claimed The time saved by the use of such equipment that these electro- may be used for more hours of operating and lytic capacitors oc- enjoyment of the equipment. Often a cupy minimum space, part will and their permanent than change its value after an hour or so sealing has longer life of use and ever before. it is practically impossible to detect a condition of this sort, without the proper measuring instruments. For that reason. we have expanded this New Transmitting Condensers to test equipment. department include OIL -FILLED- oil - impregnated construction a n d rec- Versatile Multimeter tangular shape are the Is A N1ì \C n11116;tttcr for A.C. mill u.c. use is features of the new being produced by Superior Instruments Co. Sprague CR transmit. RADIO CATALOG This model 1180 meter works on 90 to 120 volts, ting condensers. These are labeled with com- EVER plete information. including capacity. maxi- PUBLISHED! mum d.c. working voltage and maximum surge voltage. The oil used has a flash -point of 500° F. and thus affords very high protection.

New Vernier Dial s A HANDSOME nickel -silver disc, NATIONALLY in diameter, _ ADVERTISED t,, ith etched black STANDARD numerals. is the cen- MERCHANDISE tral [portion of this A m a t e u r new dial living pro- ye Transmitters, Receivers and doted by New Eng- z Parts land Radiocrafters. r Servicemen's It is driven at slow Test Instru- speed through a fric- -g ments and tion clutch by means Equipment of a neat black knob Sound Sys- which may be mount. tems of all ed at any angle front Types the center line in Inter -Office order Communica- to obtain panel tions Systems symmetry. The knob AT LOwaUT is not supplied as PRICKS! part of the outfit. It is easily mounted, being attached on the You can't afford to be without this finest of front of the panel. all radio 60 Cycles. A.C.; it tests all 4. catalogs! Whether It' Sound Equip- 5. 6, 7, 7L and octal in which it is neces. ment, Teat Instruments Or new "Rig' you base tubes, both on the meter and with a neon sary to drill only one need, you can make substantial savings at tube. Its voltage ranges are 0.15, 0 -150 and 0.750 hole for the pointer and another Wards. Every article listed In this catalog must D.C. and A.c. for the knob Lush. pass Wards "Bureau Its current ranges are 0.15. 0.150. ing. A 4" dial will .soon be available. of Standard"tests, and 65 0.750 ma.. A.c. and D.c., plus 0.1 ma. D.C. Its years of successful business on "satisfaction or your money back" policy Is your guarantee resistance ranges, 0 -500 ohms. to 5 megnhms. of Hammarlund's New qulity.Order your equipment from W a rd s, pay Its capacity scale, .0005 to I mf. and .05 to 200 Catalog for It as you use it with Wards Time Payment mf. Its decibel ranges, minus 10 to plus 19. plus THE new Hammarlund '39 catalog has 16 Plan and know that you are getting the best at 38. plus o53. Its inductance range I to 700 henries. pages. printed in two colors, and lists midget. the lowest prices! Mail the coupon today. This test instrument is provided with a sloping split stator, transmitting and micro condensers; panel and carrying case, and conies complete with various types of plug -in coils and forms; trans- test leads, charts and instructions. mitting and receiving chokes; flexible couplings; MONTGOMERY WARD coil and tube shields; variable, p GREAT MAIL ORDER HOUSES air -tuned and iron 5150 core transformers; trimming, padding and neu. RETAIL, STORES Test Meter With Unusual Range tralizing condensers; receivers and cabinets. Wige -per I Montgomery Ward 2t Company A POCKET -SIZED 5.000 -ohms -volt 14 I Dept.sw21, Chicago. U. S. A. MAIL THIS range universal micro- multimeter, known as Meterette. is being featured How To Build Radio Receivers I Please rush me New 1939 Radio COUP() by H. J. Bernard. It I Catalog FREE! employs a 3" square Itakelite -cased meter. with a This 44 page hook published by the Meissner NOW 200 microampere, d'Arsonval monnient. Mfg. Co., contains several useful formulae and I OM charts, as well as a technical discussion of design principles, general hints for the constructor, and IAddress complete instructions for the construction and operation of twenty of the most popular Meissner I Cty State kits. each description being illustrated with large detailed schematic and picture diagrams. A full list of parts for each individual set is likewise provided. l'rice of honk 50c. Cornell -Dubilier New Catalog RADIO HAMS No. 161 make the best salesmen for short -wave THIS new 40 - diather- page catalog my units to physicians. handsomely printi Large commissions paid. in two colors. gi vt - photographic illustral Grading niJr., established 1879. Me1NTOSN ELECTRICAL The Meterette has only two controls. due to a tinns. physical mean CORPORATION pecial method of combining the "Ohms" adjuster urements. electrical 223 N. California Ave.. Chicago. Ill. with the AC. -D.C. switch. A 2.500 -volt D.c. range is characteristics a n d tressed for amateur, cathode -ray and television list prices of the purposes. wide variety of ca- The ranges are: 0- 10- 50- 250 -500.2.500 volts D.C. pacitors which the at 5,000 ohms per volt; 0- 10- 100 -1.000 volts A.C. at company makes. In- 1,200 ohms per volt; 0- 2.000- 2.000.000 ohms; 0 -200 cluded ore: - eleven HEADSETS microamperes, 0 -10- 100.1,000 milliamperes. types of dry electro- tmatrurs! Are you nettle,: lytics, two types of -Tilly from your short -wan .. wet electrnl_vtics. fif- 'l' RIM t COMM ERt I \I. Insuline Catalog No. 200 teen types of paper riteWCNrr24.5.912 . Insuline Corp. of America. Pictures and descrip- condensers. two types tions of items for the Constructor. Ham and which use Dykanol, TRIMM RADIO MANUFACTURING CO. Service Man. A complete index makes this un- six types of mica 1770 W. Rerteau Ayr. Chicago. Ill. usually well laid -out catalog easy to use. condensers and two t -pes of interference filters. for Please say you saw in December, 1938 if RADIO & TELEVISION 499

www.americanradiohistory.com Radio Beginner's Course INSTRUCTION RADIO INSTRUCTION (Continued from page 465) RADIO current by means of an A.c. generator, there are a number of things that we can current. We can put the cur- HOW TO THIS FREE BOOK do with this rent through a coil and get a magnetic LEARN CODE field; and if we place another coil near to will help you Whether gnu wish to enter °din as a career or the first one we will get our current back as a hobby the All Electric Master Teleplez rode lick your code again. But we have already learned that Teaching Machine 'ill snort you how. Trleplex re .w 1 a_.b,. .m a specs your sending fn visible Ma: problems I iron is a much better conductor of magnetic ially pt,'p:rred ared lines of force than the surrounding air. If paper tape and then t sentis you are having trou- bark to you at any speed If if you It does ble learning code, then we would provide the magnetic lines of desire. develop the instead an not merely aimv you cannot force with an "iron" path of you rode. It is you need send speed of "air" path, we would get a greater transfer de. No experience for the FREE "Book needed. Facts." There are many of energy. At this point, let us no longer call now on While not desig- fine operators same trou- the coils of wire "first" coil and "second" nated as standard equipment, Teleplez is usu.! having the a the air who were Candler coil, but rather "primary" coil and "sec- may U.S. Army Posts. Naval Training Stations you are -they sent for as the Unerican Telephone k Telegraph Co. Also ble that 4.) blly practically every school In the U.S. teach "Book of Facts." - diffi- ondary" coil. (Fig. ,... prvate of the end of their code code; and many foreign governments. we beginning So far the primary and secondary have "011 complete Course. including practice ntee - Teleplez. a culties. Candler Code suppose All Electric Master plus per They took the inexpensive had the saine number of turns. But `onal fierrive on a MONEY BACK GUAR- few weeks practice FREE ANTEE. Course. and after a were that we made the secondary coil with twice the Candler System, they BOOK nbugatinn with progress. These the number of turns that it had before. We amazed at their rapid TELEPLEX CO., 67 -69 Park Place, New York were taught sound-conscious- would then find that the voltage across the operators they In Canada write: and mental coordination -soon be doubled. we tripled ness easily as print, secondary would If CANADIAN ELECTRONIC INST. TORONTO. ONT. were reading code as fact of in the secondary coil strain. nervousness, in the number turns without effort. we would get triple the voltage. Fig. 5, without conscious this job of learn- stumble and sweat over shows Don't with the using conventional radio symbols, ing rode! easy forrrthe FREE AMATEUR RADIO LICENSES (timessquicker! Send a simple transformer connected across an d any It will tell you all about the "Book of Facts !" A.C. generator. If our generator were de- DAY AND EVENING CLASSES Sstem. trained by a r. mmercial operator I Caner obtained theirkrmarvelmw ),N Champion ) MrF.lroyn or Advanced signed to deliver 110 volts. we could get licensed ama who bas years or ACTUAL the Candler Way. Beginners TEACHING EXPERIENCE. speed 220 volts in the secondary by simply wind- REASONABLE RATES GUARANTEED RESULTS ing that secondary coil with twice the num- we have hundrets of licensed ex- students._ Home Study Courses CO. ber of turns that the primary coil has. CANDLER SYSTEM AMERICAN RADIO INSTITUTE Dept.S- 12.ASH EV I LLE,NO.CAROLINA.U.S.A. Thus we can increase our voltage, but we 1123 °roadway, Dept. 12 -5T, New York City "World's Foremost Code Authority" do so at the expense of our current, which becomes reduced. the current in am- I I I times I The voltage RADIO iIIIIIIIIlll II IIIIIIIIIIIIIIII11111IIIIII11I111111111111111nIlII1111111111111111111111111L LEARN peres equals watts of power. Suppose that TELEVISION we built a step -up transformer that would 500 LICENSED graduates placed in past 7 years THERE AIN'T NO SUCH THING in shipping, broadcasting, aviation, police, etc.: give us twice the voltage of the gen- we also teach radio servicing and repairing: new W as not being able erator. If we measured the reduced amount beginners' class Sept. 12th, Nov. 7th.; 52 -page to master radio of current and multiplied it by the increased catalog free: oldest, largest and best equipped. code. The voltage, we would get an answer which we MASS. RADIO SCHOOL I RALSTON RADIO would call "watts." 18 BOYLSTON ST., BOSTON Est. 1899 The Nlcrnlo-galvanometer is shown in I CODE COURSE Fig. 6. If two dissimilar metals are brought BE A RADIO SERVICE EXPERT \1f/ will quickly pet __ E together and heated, a current of electricity Modern reeelim noire men with a thoroughly give modern traini a service work is generated. The current generated is in E confidence, accuracy and E_ LEARN AT HOME you the of heat. In speed of an expert. Hear this new direct proportion to the amount Our home Instruction method and through the service equipment otter starts you E recorded course at your dealers to- this case, if we passed a current earning money almost at opre Up E day or write wire marked A, the two dissimilar metals to $3 an hour easy in a short time. F. suffi- Write for free honk. = RALSTON RECORD COMPANY connected to the wire would increase Radio Training Assn of America 5433 WILLOWS AVE. PH ILA.. PA. ciently in temperature to develop an electric Dept. RT -812 4.125 Ravenswood Ave.. Chicago I I I I I I I I I I I I I I I I I I I I I I I I I I R 1 t 11 t 111111111111111111I I I 111111 11 111111111 11 111111111111111111111111 current which would be indicated on the galvanometer. RADIO ENGINEERING LEARN CODE RIGHT Still another method of measuring cur- RCA Institutes offer an intensive coursa of weather interference-Speed rent is through the use of a hot -wire am- high standard embracing all phases of Radio beatsbea tshaying someone and Television. Practical training with modern range 5 to 40mW.P.M. Radio r Morse. meter, as shown in Fig. 7. In this instance, equipment at New York and Chicago schools. Ith 10 tapes d hook of the wire Also specialized courses and Home Study instructions SS20.23 when a current passes through Courses under "No obligation" plan. Catalog book and ex- Dept. SW-38. and. .00 marked A, the wire gets warm insttructtions t rented) move the Standard with 10 tapes and pands, causing the spring to Inc. hook of instructions 53.00 first RCA INSTITUTES, month, $2.25 each additional month. indicating needle over a scale. The amount A Radio Corporation of America Service Complete oscillator equipment less wire will expand depends 1154 Mart, Chiriqui batten, 353036.50 that a given 78 Variek St.. New York. Merchandise for details today upon the amount of current. INSTRUCTOGRAPH CO. However, the most widely employed cur- Dept. SW -12 Chiggo, Ill. Representativestesiafo for rent or voltage measuring device is the Radio College of Canada 863 May Street Toronto D'Arsonval instrument, shown in Fig. 8. Once again we have our powerful steel magnet. Placed between the poles of this RADIO COURSES magnet is a tiny coil of wire, delicately RADIO OPERATING- BROADCASTING pivoted in place. A needle pointer is con- For Gov't License Preparation nected to the coil and so placed that it can R \nIO- RADIO SERVICING - practical course CRAFT AMATEUR COI)Ea TELEVISION a scale. The needle is held in >y 1 phasess RADIO move over r radio-servicing.. ELECTRONICS -1 yr. day course 2 yrs. eve. by means of a small. fine public address. Day and Evening Classes. Booklet Upon Request. zero position construction. croni, New York Y.M. C.A. Schools spring, quite similar to the hair springs fntlrfarimlle. etc. Featrres watches. inReaeh li t o NweLaest 6 W. Seth Street New York City Z) found in Tubes-Data Sheets-Tele- vision-Operating Now let us pass a small current through Over 175 illustra- Wens in every i the coil; this will create a magnetic field To readers of this nouncement we a about the coil. This magnetic field will tend SPECIAL OFFFRSeveÌ- n field Months. Subscription RADIO to align itself with the magnetic RADIO -CRAFT and o FREE. copy of the 64 -,age already existing between the poles of the loss RADIO ENGINEERING, NNUAÌ magnet ; hence, the coil of wire listing, aviation : permanent New ex- and police radio, servi. subscri metre can telegraphy and telephony, Morse Isle. np!.r rad will move. tend their present t sub- ailway accounting taught thoroughly. Engineering course scription by check. money order nine months' duration equiralent to three years of (Lesson 3 next Month covers resistance, Remit ONE DOLLAR c' School stamps for year FREE BOOK and Seven on allege adla Work. All expenses low. Cal sing free. Sobscrint.on to RADIO- CRAFT. established 1474. inductance and capacity and oscillatory STREET. 9XEWUVSSoN Dodge's Institute, Turner St., Valparaiso, Ind. circuits.) RADIO -CRAFT 500 Please say you saw it in RADIO Si TELEVISION RADIO & TELEVISION

www.americanradiohistory.com World Short Wave Stations RADIO INSTRUCTION ..tutted front. page -47(1) Mc. Call

3/ Met. Aoadcast iland 9.523 ZRH ROBERTS HEIGHTS, S. AFRICA. 31,5 m., Addr. (See ZRK, 9.606 Ott LEARN Mc. Call c.) Daily exc. Sun. 5 -7.30 am.; Sun. 5.30 -7 am. 9.600 RAN MOSCOW, U.S.S.R., 31.25 m. 9.520 Daily exc. Sur. 6.10 pm. Sun. 6.7, OZF SKAMLEBOAEK, DENMARK, 31.51 9.15 -10 pm. m., Addr. Statsradiofonien, Heib RADIO ergsgade 7, Copenhagen., 2 -6.40, 9.595 HBL GENEVA, SWITZERLAND, 31.27 m., 8 -II pm. Addr. Radio Nations. Irregular. 9.520 YSH SAN SALVADOR, EL SALVADOR Here's Your 9.590 VUD2 DELHI, INDIA, 31.28 m. Addr. 31.51 m., Addr. (See 7.894 mc.) VUD3 All India Radio, 1.30 -3.30 am Irregular 6 -10 pm. 7.30 am.-I2.30 pm., 8.30 -10.30 pm. Complete 9.510 GSB DAVENTRY, ENGLAND, 31.55 m., 9.590 PCJ HUIZEN, HOLLAND, 31.28 m Addr. (See 9.580 roc. -GSC) Radio Addr. (See 15.220 roc.) Sun. 2 -3, 1.30 -4, 4.15.6, 6.20.8.30, 9.20 -11.25 the )'ou "In ed t.o kn.Yw 7 -9.25 about Radio. Electricity. Sound, Tele- pm. Tues. 1.45.3.40, 7.15- cm. Education vision. Cathode -Ray Tubes, er.. etc. 8.45, 9 -10.30 pm., Wed. 7.15.8.30 1 r o qualify for a go,nÌ-nayIng 9,510 HJU BUENAVENTURA, radi,i job. Here pm Fri. 8 -9 pm, COLOMBIA, Sound. Si,,, at last is praetwal. 31.55 m., Addr. National inexpensive way to get into the nnry Rail. and Musa fe Ì,,. save xyour time and save 9.590 VK6ME PERTH, W. AUSTRALIA, 31.28 m., ways. Mor., Wed. and Fri. 8- Electrons 'm ith the w' rlds moat your Addr. Amalgamated Electric Cur- Wit te -Chiraniis Ra Physiics Wireless of Course! Thousands of successful Australasia, Ltd. 6 -9 am. exc. Sun. 9.510 HANOI, FRENCH INDO- rent-Electric - CHINA. 1-nits their lint 31.55 m. ''Radio Hanoi ", and dr. training throughhrough this lark. 9.590 VK2ME SYDNEY, AUSTRALIA, 31.28 m., Addr, cults-Resist. Addr, Amalgamated Wireless of Radio Club de L'Indochine. 12 ante -. Ohm 's EASY SHORT -CUTS m. -2 am., 6 -10 Compactly Australasia, 47 York am. Law - Bat - condensed in this one Ltd., St., teries -Mag- great Is,ok ru11 get separate Sun. 1 -3 am.; 4.30 -8.30 am.; 9 -11 9.500 VK3ME MELBOURNE, AUSTRALIA, 31.58 netism lies'. IcarnT' en rse of self-Instrue- am. m., - preparevl by that n, 1 radio Addr. Amalgamated Wireless Electrolilagne- authority and instructor. wAlfred A. of Australasia, 167 Queen St. tism-Trana- Chit-anti. Faach ction is highly sim- 9.590 W2XE NEW YORK, N. Y., 31.28 m Addr. plified. clear and easy to understand- Daily except Sun. 4 -7 am. fornmers - In- yet CBS, 485 Madison Ave., Irregu- ductance each is so thorough and practical that minute yu spend on this lar. 9.500 XEWW MEXICO CITY, MEX., 31.58 re. - lr e ery system- Pushes Addr. Apart. 2516. Relays XEW. Alternating aheadi , ralotining. You check 9.590 W3XAU PHILADELPHIA, Current your with self- testink PA., 31.28 m. Re- 6 pm. -12 m. Cir- review oI,rogressw. no lays WCAU. cuits- Filters o r knowledge Na 9.500 ld mathematicshict` inins- OFE LAHTI, FINLAND, 31.58 m., Addr. - Eventhing is h,ined mat 9.58C GSC DAVENTRY, ENGLAND, Measuring lIred. simply. thoroughly. Na, won- 31.32 m., Finnish Brest. Co., Helsinki, 2.15.5 der I '' l ru liants Ghlrals Radio Physics Conne Addr. B. B. C., Portland PI., Pm. Is used by more radio schools and London, W. I, 4.15 -6, 6.20-8.30, -Radio students han any other radio hook in 9.20.11.25 9.500 HS8PJ BANGKOK, SIAM, 31.58 m. Thurs- Wares: Radi- the pm., 9 am. 12 n. Now e' all you do to started: day, 8 -10 are. ations - get B r oadcast coupon-mail it today. 9.580 VLR MELBOURNE, AUSTRALIA, 31.32 Take 10 days M1ver he 9.488 EAR MADRID, SPAIN, 31.6 m., Stations - ,f you don't feet 't will hells m. Addr. Box 1686, G. P. O. Addr. (See 9.860 mc.) 7.30 Recelving , and your money will Da ;1y 3.30.8.30 am. (Sat. till 9 -8,30 pm. Equipment St immediately r em.) Sun. 12.01 -7.30 am, Mon., Tues., Thur., Sat- at 9.30 Vacuum nothing' man, let's get going! Also pm. - daily exc. Sat. 9.25 pm.-2 or 2.15 also. Tubes -!radio and am. Sat. 5 -10.30 pm. Audio End of Broadcast Band Erequency - 9.580 OAX5C ICA, PERU, 31.32 m. Radio Uni - Amplitication versal 6 -10 pm. - .'uperhet- 9.445 HCODA GUAYAQUIL, era,lynes 9.570 KZRM MANILA, P. 1 31.35 m., Addr. ECUADOR, 31.77 Loud Speak- . Irregularly 10.40 Erlanger & Galinger, Box 283. till pm. ers - Battery Operated lie - Sun. 3 -10 am. Dally exc. Sat. 9.437 COCH HAVANA, CUBA, 31.8 m., Addr. celtupply 4.30 -7 pm., 11.15 pm. -12.15 am. 2 B St., Vedado, 8 a.m. -9.30 pm. Daily exc. Sun. 4 -10 am. Sun. 8 am. -12 m. nits -Elec- trlc Receivers 9.570 WIXK SPRINGFIELD, MASS., 31.35 m., 9.380 - TANANAR IVE, MADAGASCAR, - .t ut nnmhile Addr. Westinghouse Electric & 31.96 m. Addr, Le Directeur des and Aircraft PIT, Mfg. Co. Relays WBZ 7 am. to Radio Tananarive, Adminis- Receivers - 1 am. Sur. 8 am. -1 am. tration PTT. 12.30 -12,45, 3.30 -4.30, I'It oat dgraph 10 -11 am. Sun 2.30 -4 em, Pickups - 9.560 DJA BERLIN, GERMANY, P.-1. Systems 31.38 m., 9.370 XOY CHENGTU, 32.02 Addr. Broadcasting CHINA, re., -Short - t cave House. 12.05 - 9.45 -10.30 a.m. lterei vers II 7 -10.45 am., pm. l' h o toetectrlc 9.355 HCIETC QUITO, 9.550 TPBII PARIS, FRANCE, ECUADOR, 32.05 m., I ell., Tele- 31.41 m. Addr. Addr. Teatro Bolivar, Thurs. vision- (See 15.245 mc.) un- -An- 2 -4 am., 11.15 til 9:30 p.m. tennas a n d n, -6 pm. Grounds 9.350 COCD HAVANA, 32.08 m., - 9.550 W2XAD SCHENECTADY, N. Y., 31,41 m., CUBA, Addr. Box 2294- Relays CMCD 10 - servicingng Re- General Electric Co., 6.15.10 pm. a.m. I I.30 pm. Sun. 10 am. -9 pm. ceivers 9.550 OLR3A PRAGUE, CZECHOSLOVAKIA, 9.345 HBL GENEVA, SWITZERLAND, Sound Motion 32.08 m., Ì'Ìct It res 31.41 m. (See 11.840 roc.) Irreg. Addr, Radio Nations- Off the AppendiTes- 9.550 XEFT VERA CRUZ, MEX., 31.41 m. 10.30 air at present, -tsfi Review am. -4.30 Questionsions for pm., 10.30 pm. -12.30 9.330 OAX4J LIMA, PERU, 32.15 m Addr. Box RADIO & TECHNICAL Self - PUBLISHING CO.. as As- 1166, "Radio 12 Universal." n.- t N I) 1)07. - to Place, New York. Dept. 9.550 YD8 SOERABAJA, JAVA, 31.41 m., 3 pm., 5 pm. -I am. E N S OF RST -128. Addr, N.I.R.O.M. Daily exc. Sat. O T H E R Here n ga. 184.50 foreign. 9.300 HIG CIUDAD TRUJILLO, D. R., 32.28 for v cop` of RADIO masts,. 6-7.30 4.30 10.30 SUBJECTS! pm., to am. Sat. m. 7.10 -9.40 am. 11.40 COURSE. I stpaid 4.30-11.30 am. am.-2.10 with 10 -day money -back Lvar. pm., 3.40-9.40 pm, 9.550 VUB2 BOMBAY, INDIA. 31.41 m.. Addr. 9.280 HC2CW GUAYAQUIL, All India Radio. 9.30 -10.30 ECUADOR, 32.31 m., pm., 11.30 -12.30 N.LNE i2 m. -2.30 am. am. p.m., 8 -1I pm. 972 PAGES 9.540 DJN 9.200 COBX HAVANA, CUBA, 32.59 m. Addr. BERLIN, GERMANY, 31.45 m., 508 Innuss AnnRFAN Addr, (See 9.560 roc.) 4.50 -10.45 San Miguel 194, Altos. Relays CMBX 7 am.-I2 m. 856 Review

CITY STATE . 9.540 HJSABD CALI, COLOMBIA, 9.125 HAT4 BUDAPEST, HUNGARY, 32.88 ro Questions 31.45 m Addr. Addr. E Send free descriptive rter:,- La Voz de Valle. 12 n, -1,30 pm -, "Radiolabor," Gyali.ut lure. 5.10-9.40 pm. 22. Sun. and Wed, 7 -8 pm., Sat. 6 -7 pm. 9.540 VPD2 SUVA, FIJI ISLANDS, 31.45 m., 9.100 COCA Addr. A.nalgamated Wireless of HAVANA, CUBA, 32.95 m., Add,. YOUR FUTURE IN Australasia, Ltd. 5.30 -7 am. Galiano No. 102. Relays CMCA 9 am. -12 m. 'These growing industries RADIO 9.535 JZI TOKYO, JAPAN, 31.46 need trained men for sales, Addr. 9.091 PJCI CURACAO, CURACAO. 50.33 (See 11.800, m., service, operation. Your JZJ) 2.30 -4, 4.30- Mon., Wed., Fri. TELEVISION 5.30 6.36 -8.36 pm., chance for employment and pm. Sun. 10.36 am. -12,36 Send for nee book- pm. advancement depends on let that shows 9.535 BERNE, SWITZERLAND, 31.46 m., how - 9.030 COBZ HAVANA, thorough training. National 1 -2 pm, exc. Mon. and Tues. CUBA, 33.32 m., Radio foro a theses opals Salas Addr. P. 0. Box 866. Schools offer you time -test- tun ities. 9.530 W2XAF SCHENECTADY, 7.45 N. Y., 31.48 m., am. -1.15 am. Sun, 7.45 am: I2 m. ed training. Complete, Addr. General Electric Co. 4 Relays CMBZ, modern facilities and equip- p.m. -12 m. Sat. I pm. -12 n ment in the largest trade 8.965 COKG 9.530 VUC2 CALCUTTA, INDIA, 31.48 m. Addr. SANTIAGO, CUBA, 33,44 m. Addr. .sellout in the W. st. All India Radio. 2.06 -4.06 am. Box 137. 9 -10 am., 11.30 am. -I.30 pm., 3.4,30, 5 -6, 10.11 pm., 12 9.526 XEDQ GUADALAJARA, GAL., MEXICO, m. -2 am. NATIONAL SCHOOLS 31.49 m. Irregular 7.30 pm. to 8.841 HCJB 4000 S. Fig Street, Los Angelas 12.30 am. QUITO, ECUADOR, 33.5 re. 7 -8.30 are., 11.45 am. 2.30 pm., NATIONAL SCHOOLS, Dep, RTt'L. 1e,, Annie, 9.526 ZBW3 HONGKONG, CHINA, 31.49 5 -10 pm., except Mon. Sun, 12 n.- m., H.... wad teer Rd,o m.11 men Booklet. Addr. P. 0. Box 200. 11.30 pm. 1.30 pm., 5.30 -10 pm. to I NAME am., 3 -10 am. 8.700 HKV BOGOTA, COLOMBIA, 34.46 m. ACE Tues. and Fri. 7 -7.20 ADDRESS 9.525 LKJI JELOY, NORWAY, 31.49 m. 5.8 pm. am. (Continued on page 505) LcI STATE J for December, 1938 Please say you saw it in RADIO & TELEVISION 501

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HERE is a brand new book -with an unusually interesting content. The text - prepared by the Editorial Staff of RADIO AND TELEVISION, contains a variety of material which only experts could select and incorporate in such an excellent volume. "SHORT WAVE RADIO QUIZ BOOK AND KINKS" cannot be bought-it is sent to you absolutely FREE with your subscription to RADIO AND TELEVISION at the Spe- cial Rate of Seven Months for One Dollar. (Old subscribers may get this book by extending their subscription.) The book contains 64 pages with a heavy flexible colored cover. It measures 51/ x 81/ inches, and includes hundreds of photographs and diagrams. The contents are outlined below. Contents of the "QUIZ BOOK" Questions and Answers Cov- How to Connect an R.F. HOW TO "HOOK UP"- 2 Other FREE Books ering S -W transmitters. Stage Ahead of Your Pres- S-W Converters A B C OF TELEVISION Questions and Answers Cov- ent Receiver. rtnta na latest ma te - ering S -W Receivers. Noise Silencers iel oh re lerisio Dozens of Novel New Hook - ® dereltheo y rats. I. -Wave Transmit- theory o[s Ultra- Short Ups for the S -W Experi- Power supplies vi

110 Volt D.C. Transmitter - Part II Conclusion Herman Yellin, W2AJL

Top and bottom views of the D.C. Transmitter

are taken from the coils besides Tri -f et Oscillator Used Tuning the cathode circuit is not at all Two taps popular, critical, the same setting of the cathode the end leads. THE oscillator is of the justly entire coil of -tet" type. This oscillator condenser (Cl) holding good for the entire For 160 -meter crystals, the time -tried "tri is used; for 80 meter crystals only makes use of a cathode coil tuned to ap- amateur band in use. A little juggling of 35 turns fre- the turns and the positions of the taps re- 14 turns, and for 40 meter crystals 5 turns proximately one and a half times the out used. The plate sults in a value of inductance for each band, are used. The unused turns are shorted quency of the crystal being switch (SW -1). tuned to the second harmonic such that the cathode condenser need not be by the rotary tap circuit is then As the photo indicates, mount the of the crystal frequency. readjusted for crystals on different bands.

Please say you saw it in RADIO & TELEVISION RADIO & TELEVISION 502

www.americanradiohistory.com cathode coil socket about % inch behind G.EPHONOGRAPH MOTOR the coil switch, making for very short leads. The cathode condenser is mounted along- Formerly Only side the oscillator tube socket with its shaft Sold for slotted with a hacksaw and protruding above $15.00 the chassis for ready adjustment. 95 Although a thermocouple milliammeter VARIABLE will measure the crystal current accurately, speed induc- such is not needed, especially with tion type selfparting. accuracy 110 volt. 25 to GO cycle, A.C. with the high expense of this type of meter. A 60 R.PP.M. Can be installed cindplaceof old-fashioned, th nd0- milliampere (2 volt) pilot -light bulb will winding speed motor. Also ideal for display turn table. and a hundred other uses. These General Electric Motors serve admirably, indicating when the cur- are brand new. in original factory cartons. is too O. E. Electric Phonograph motor as de- 5.95 rent high and providing a valuable scribed aid in tuning the oscillator for optimum out- Sal poing Weight-12 Ms. put. The allowable current varies among different types of crystals, being about 100 NEW "TC" milliamperes maximum for the variable fre- Westinghouse quency crystal used by the author. TRANSMITTING Power Generator Oscillator Coupling Manufactured for U. S. S..u, il Corn 200 Walt. The oscillator is inductively coupled to CONDENSER 1111 V. AC the amplifier by means of a split grid coil Hammarlund's new "TC" transmitting con- wound on the sanie form as the oscillator densers include many outstanding and ex- plate coil, one section on each side of the clusive features. They are available in a wide range plate coil. Each of the grid coils (L -2 & of capacities and voltage rat- ings with both single and dual stators. L -3) consists of the same number of turns Wide plate spacing permits their use in and is spaced the same distance from the transmitters up to I kw. input. Special full ends of the plate coil and is wound in the floating bearing construction eliminates binding and twisting. Heavy polished same direction. Fxcitation to the amplifier aluminum plates with rounded edges inis determined by the number of turns in crease efficiency. Write for bulletin describing special rotor and contact construction the grid coils and the distance separating and other details. them from the plate coil winding. Increasing the number of turns, or winding the grid HAMMARLUND MFG. CO., INC coils closer to the plate winding, will 424 W. 33rd St., N.Y.C. increase the excitation. If the coil winding RT -12 ( ) Please A. C. ELECTRICAL specifications are followed exactly, the ex- send "TC" bulletin POWER Name from Windmill, from available Waterpower. from your citation will be just right, and no adjust- Automobile. from your Motorcycle. from your Bicycle. Foot - ments to the coil should be necessary. pedals or Handtrank I for transportable Radio Address Strong Transmitters. Floodlights. Artsertising Signs /: do you want to It will be noticed that both the oscillator operate AC Itdin sets from 32 V. Dr farm light sys- and amplifier plate coils are center -tapped. City State tems; Operate two generators in series to get 200 V. Ar: obtain two phase and three phase AC. etc.. In Canadian etc. winding these coils, each half of the 0111ee: 41 West Ave. No , Hamilton. ONT. There Are Over 25 Applications coil wound as a separate coil. The ends Some of which are: of the coils then appearing at the center A.C. Dynamo lighting from HAmmARLUnD eight to ten 20 Watt 110 of the dual coil are soldered in- Volt together lamps. Short tVace Transmitter supplying 110 Volts side the coil form, and one of AC for perating "Main" transmitter. Operating 110 V. the wires AC 60 Cycle Radin Receiver In DC districts. Motor Gen- brought to the proper coil form prong. erator. Public Address Systems. Electric Sirens On motor boats. yachts. etc. Camp Lighting. Short wave rtificial Taps on the oscillator cathode coil are "fever" apparatus. Television. l'elton waterwheel for made in the same manner. DEPENDABLE lighting or other purposes. Airplane: for lighting strong searchlights t electric signs. Laboratory work. ele. etc. w to r a IL I'. needed to run generator. Amplifier BLUE -PRINT CONDENSER 22 x 28 in. and FourPage 8!a x 12 in. INSTRUCTION SHEETS The amplifier is quite conventional, FREE with con- Generator. sisting of four 25L6G tubes in push -pull G tor, as dcserlbed. Including four replacement carbon brushes. Blue -print and parallel. Between the grids of each pair of instructions 790 parallel tubes is placed a small R.F. choke Send 82.00 deposit, balance C.O.I). (RFC -3) to prevent parasitics. These con- Shipping weight IS lbs. sist of six of 18 (Replacement carbon brushes bought separate 11.50 per turns No. hookup wire, set of four. Set of instructions bought separate í1.00.1 air -wound to a diameter of H inch and the MONEY-BACK GUARANTEE turns spaced about twice the wire diameter. WELLWORTH TRADING Insertion of these chokes effectively COMPANY squelches any tendency towards parasitics. 560 West Washington Blvd., Dept. RT -1238. Chicago. III. Build your own to Cross neutralization is employed in the exact needs, with these amplifier, using a pair of neu- AEROVOX uncased variable paper tralizing condensers having a maximum sections. ELECTRICAL capacity of 6 mmf. Condensers with as low a minimum capacity as possible should be N o n-i n d u ctively used, since interelectrode wound paper and foil OCCUPATIONS the capacity of sections. Thoroughly the 25L6 is quite low. These condensers are impregnated with FOR BOYS mounted on the chassis with their shafts high- melting -point extending above the chassis to facilitate compound. By Lea N. Kllnefelter, up tuning the transmitter. As is the case Any desired voltage and B. S., M. A. with all the other variable condensers, these capacity combination. Black varnished paper Units clamped or taped wrapper. S" wire leads. condensers must be insulated from the together. And you save Covering the entire field of electrical chassis. Ordinary much money. occupations available. Radio. Telegraphy. extruded fibre washers Ignition and Electrical Engineers, Power will prove adequate because of the low In 200, 400, 600 and Station Operators. Army & Navy Spe- voltages encountered. If the condenser 1000 v. .1 to 2 mfd. cialists, etc.-Each fully describes his shafts are slotted with a own type of work and answers typical hacksaw, the con- questions. Recommended by electrical densers can be adjusted with an insulated magazines, Ask local AEROVOX jobber for engineers, instructors, and screw -driver and no knobs will be needed. these and other types you need. Government officials. 64 -page illus- Get full In hit, =t co t boc-or, write us trations. For YOUR COPY, send coupon wiring the push -pull amplifier stage, direct. below: keep the leads from the grid coils (L -2 and L-3) to the grids of C. P. DUTTON a CO.. Inc. the 25L6Gs equal in Deli. 2.-300 Fourth Ave.. N.Y.C. length. Likewise keep the wires from the aenuemen: sz nclosed, for hich please e c postpaid my copy of ELECTRICAL OCCUPATIONS plates of the tubes to the ends of the plate FOR BOYS. coil (L -5) and to the split stator tank Name condenser (C -6) equal in length. A bal- Address anced wiring layout will be much freer from CORPORATION 70 Wiuuhingwn City Stau parasitics and will not prove difficult to Sc Brooklyn- N. Y. 1 neutralize. (Continued on following page) 1 for Please December, 1938 say you saw it in RADIO & TELEVISION 503

www.americanradiohistory.com 110 Volt D.C. Transmitter (Continued from preceding paye) FOUR NSW 10 RADIO BOOKS Tuning Up RADIO FANS EVERYWHERE -these little ten cent text books give you an excellent With all wiring completed, the transmitter foundation for the study of radio. They are clearly written, profusely illustrated and is ready to be tuned -up. This is not at all contain over 15,000 words in each book. You'll be amazed at the wealth of information difficult, since once the preliminary adjust- these volumes have. They are handy for review or reference books. ments, such as adjusting the oscillator cathode condenser and the amplifier neutralizing condensers have been completed, -----_ there are only two tuning controls. GERNSBACKS EDUCATIONAL LIBRARY N 17 After the transmitter has been connected to the 110 volt D.C. line, first being certain BEGINNERS that the positive side of the line will connect to the plates of the tubes and not to RADIO fAr110US fl IAO the chassis, close switch SW -3, lighting DICTIONARY s4 DIAGRAMS the filaments of all the tubes. Let the tubes 6H Rette, E:rAb.ry warm up for about 30 seconds and then (10 ? . GERNSBACK close switch SW -2 which will apply the MINT plate voltage. With the meter plug inserted in the oscillator cathode jack (J -1) we are ready to tune the oscillator. Insert the EDUCATIONAL crystal in the crystal socket, and (assuming that operation of the transmitter is desired on the second harmonic of the crystal) coils in the oscillator n - LIBRARY make sure that the ?f and amplifier plate circuits are set for the RADIO PUBLICATIONS. 101 HUDSON ST NEW 10171t Nf RADIO PUBLICATIONS lel NDDSON ST.NIwtalaIT band of double the oscillator frequency. With the cathode tuning condenser set at about 75 percent of its maximum caoacity N0. 7 -HOW TO READ RADIO DIAGRAMS NO. 5- BEGINNERS' RADIO DICTIONARY and the switch SW -1 set at the proper Are you puzzled by radio language? Can you define fre- All of the symbols commonly used in radio diagrams are oscillator plate quency? Kilocycle? Tetrode? Screen grid? Baffle? If presented in this book, together with pictures of the tap for the crystal, vary the you define these very common words and apparatus they represent and explanations giving an be found cannot radio book, by tuning condenser C-4. A point will of other, more technical, terms used in all radio easy method to memorize them. This Robert dozens well radio writer and member of decreases and then instruction books, need this book in Eichberg, the -known where the plate current magazines and you the staff of RADIO -CRAFT magazine, also con- as modern as editorial the point of minimum your library. It's tomorrow -right up to tains two dozen picture wiring diagrams and two dozen increases again. At the minute. It tells you in simple language just what schematic diagrams of simple radio sets that you can plate current, the ,late circuit is tuned to the words that puzzle you really mean. You cannot build. Every diagram is completely explained in language fully understand the articles you read unless you know which is easily understood by the radio beginner. More the second harmonic of the crystal fre- what radio terms mean. This is the book that explains advanced radio men will be interested in learning the quency. Remove the meter plug from the the meanings to you. Can you afford to be without lt, derivation of diagrams, and the many other Interesting even one day longer? facts which this book contains. oscillator cathode and insert it in the amplifier cathode jack (J -3) and short the telegraph key. Varying the amplifier plate condenser will also result in a dip in plate 613111561013 OBCATDNAL LIBRARY N ?6 GERNSBACKS EDUCATIONAL MARY N! 8 current at some setting. This indicates resonance with the oscillator. For the wow TO HMI initial tuning of the amplifier, keep the Air RADIO fat neutralizing condensers at their minimum capacity setting. The antenna should be fVNRADro BEGINNERS disconnected from the amplifier. FOUR Neutralizing We are now ready to neutralize the amplifier stage. The meter plug should be inserted in the amplifier grid jack (J -2) and the plate and screen voltages disconnected from the amplifier. The meter will then read rectified grid current, which is a 800K51 measure of the amount of excitation to the amplifier. Rotating the amplifier condenser RADIO PUBLICATIONS. rot HUDSON STREW TORBAY \ RADIO PUBLICATIONS 101NUa50N ST. NEN'vOSN AT through resonance will, if the amplifier is not neutralized, result in a flicker of the BEGINNERS NO. 6-HOW TO HAVE FUN WITH RADIO NO. 8 -RADIO FOR grid current meter ; in general the greater Hugo the internationally famous radio pioneer. Stunts for parties. practical jokes, scientific experiments Gernsbark. the flicker of current the further away be done with your radio author and editor. whose magazines, RADIO & TELE- and other amusements which can are read by millions, fascinating volume. It tells VISION and RADIO -CRAFT from correct neutralization. When the stage set are explained in this scores another triumph with this new book. Any beginner a talk to silent will be ab- how to make newspaper -how produce who reads it will get a thorough ground work in radio is perfectly neutralized, there music for dances -how to make visible music -stow to theory. clearly explained in simple language. and through solutely no flicker of the grid meter. make "silent radio" unit. usable by the deafened - the use of many illustrations. Analogies usedu ed to make been neu- how to make toys which dance to radio music-sixteen the mysteries of radio as clear as +2r i 4 ". It also After the amplifier stage has clever and amusing stunts In all. Any of these can be contains diagrams and instructions for building simple crystal for the novice. want to know tralized and tuned to resonance the done by the novice, and most of them require no mor radio sets, suitable If you how and receivers work, how radio wates be and adjusted equipment than can be found in the average home. End- transmitters oscillator should checked be yours you traverse space. and dozens of other interesting facts about less hours of added entertainment will if of this is the for optimum output. With the meter in the Instructions in this lavishly illustrated this most modern means communication, follow the given book for you! amplifier grid jack and the key down, book. Other Titles in This Series! vary the cathode condenser slightly for MAIL COUPON TODAY!! Four other volumes in this ten -cent radio hook series - maximum oscillator output, as indicated by each On popular subject -are available. The titles are: a maximum reading of the grid current. r No. I -HOW TO BUILD 4 DOERLE SHORT -WAVE RADIO PUBLICATIONS. Deot. R &T 12 -38 SETS It will be found that this condition will al- 101 HUDSON STREET. NEW YORK. N. Y. No. 2 -HOW TO MAKE THE MOST POPULAR ALL - with a small dip in the current WAVE I- AND 2 -TUBE RECEIVERS most coincide Gentlemen: Please send immediately. POSTPAID, the No 3- ALTERNATING CURRENT FOR BEGIN- flowing through the crystal, as indicated by book numbers circled below. I am enclosing... -cents NERS the crystal pilot lamp bulb. The setting -each book being 1Oc. No. 4 -ALL ABOUT AERIALS of the condenser for minimum crystal cur- 1 2 3 4 5 6 7 8 BOOKS ARE ALL UNIFORM rent is the desirable position. 0 Send FREE listing of 98 new 10c publications. Every book in the GERNSRACK EDUCATIONAL LT- iiRARY has 32 pages -with Illustrations varying from If operation is desired on the fundamental 30 to 66 in number. Each title volume contains over frequency of the crystal, the cathode switch Name 15,000 words. Positively radio's greatest book buys! If you do not think these books worth the price asked. is set so that the entire cathode coil is return them in 24 hours and Your money will be instantly oscillator then becomes Address refunded. shorted out. The a standard pentode oscillator ; tuning the using City State RADIO PUBLICATIONS transmitter remains the same as when by or money der-- register letter if oscillator as a tri -tet, except that the Remit cheek 101 HUDSON STREET NEW YORK, N. Y. the You send cash or unused U. S. postage stamps. oscillator cathode circuit is not used.

RADIO & TELEVISION 504 Please say you saw it in RADIO & TELEVISION

www.americanradiohistory.com World S -W Stations (Continued front page 501) BROWNING "83" UNUSUAL Mc. Call 8.665 COJK CAMAGUEY, CUBA, 34.64 m., Build This Wonderful CHRISTMAS GIFTS Addr. Finlay No- 3 Altos. 5.30- 6.30, 8 -11 pm-, daily except Sat. and Sun. New Receiver Yourself U. S. 8.665 W2XGB HICKSVILLE, N. Y., 34.64 en., Addr. Press Wireless, Mon. to IN ONLY 6 HOURS! ARMY Fri. News at 9 am. and 5 pm. 8.580 YNPR MANAGUA, NICARAGUA, 34.92 SIGNAL m. Radiodifusora Pilot. 7.894 YSD SAN SALVADOR, EL SALVADOR, CORPS 37.99 rn., Addr. Dir. Genl. Tel. 8 Tel. 7 -11 pm. LAMPS 7.870 HCIRB QUITO, ECUADOR, 38.1 m. La The lamp Voz de Quito. 9.11 pm. 7.854 HC?JSB GUAYAQUIL, ECUADOR, 38.2 m. of 100 uses Evenings to II pm. 7.797 HIP GENEVA, SWITZERLAND, 38.48 en., Stout Signalling Addr. Radio- Nations. Night Bowling Alleys 7.510 JVP NAZAKI, JAPAN, 39.95 m., 8 -9.30 Trailer Lamp 04 BANDSPHASE INVERSION P.P. AUDIO Motor Boat Races Night 7.450 TI2R3 SAN JOSE, COSTA RICA. 40.27 m. BAND PASS I.F. DX RECEPTION Auto, Truck and Trailer " Radioemisora Athena ". 9.30 -11 ,54 to 2I MEGACYCLES IN 4 BANDS Camps Fm., Tractor Light exc. Sun. Camp Light 7.410 HCJB4 QUITO, ECUADOR, 40.46 m., 7- This is ONE kit that is really a Barnyard Lighting 9.30 pm. irregularly. knockout. Designed by Mr. Glenn Night Fishing Browning Radio Shacks 7.410 YDA TANDJONGPRIOK, JAVA. 40.46 of the Browning -Drake Bungalows Addr. N.I.R.O.M., Batavia, fame, it is the last word in perform- Picnics. etc. Scouts Signalling 10.30 pm. -2 am.; Sat. 7.30 pm: ance. The chassis is drilled to accom- 2 am. Large size- 121/x wide. 5.4" deep. I high inrhal- modate any three extra circuits that ing socket. fitted with IO" silver fr.Inas. Plated r you may decide nothing to break,. Packed h, I 7.380 XECR MEXICO CITY, 40.65 to try out. Its full case MEX., m., with hinged cover. "'. 9, vision 71,¢" Scale Evrrying contains weatherproof e Addr. Foreign Office. Sun. 7.8 makes S.W. tuning nlug, extra 2 xro uild, to e_ aph g- pm. a pleasure. Write at once for FREE netting key and 10 page U.S. Army Manua 1. Shipping description. IS tbs. Price 0a 5 7.220 HKE BOGOTA, COL., S. A., 41.55 m. the Government s h o u t FOB.. N VCal . Tues. and Sat. 8.9 pm. Mon. and $25.0°1 3 for 510.00 Large lamp. Thurs. 6.30 -7 pm. with hulk. but with - sus FOR THE AMATEUR out case d extra fittings a for 55.00 Small xlze -0" wide. 5" deep. 7.200 YNAM MANAGUA, NICARAGUA, 41.67 The famous Bandswitch Triplette, 5P -5G socket. 101'," high including lamp furnished with O volt bulb I', \ C. m. Irregular at 9 pm. and 5H are expressly designed current. One extra bulb furnished5c to cover free. 'Add el bulbs. 15c each. 10 to 160 meters for Crystal oscillators; Packed n gn 7.177 CR6AA LOBITA, ANGOLA, PORT. WEST Frequency meters; monitors ; field strength Shipping weight' c'2 Iha.IPrice $1.95 Wog, AFRICA. 41.75 m.. Wednesday the Government a 1, o',i i F.0.8. N. Y. indicator, etc. Send for free circuit dia- gloom 3 for 55.00 ,J Saturday 2.45 -4.30 pm. gram as to their wide use. These lamps will n 7.100 FOBAA PAPEETE, TAHITI, 42.25 m., World make attractive souvenir of the Addr. War fr , r Club.t,. Motor Boat. House. Den.. Radio Club Oceanien, Tues. and BROWNING LABORATORIES, INC. .harf. omit,' Home. They will also be an acceptable v o any of your friends. Fri. 11 pm.-12.30 am. WINCHESTER, MASS. Dept. T -II 7.088 PIIJ DORDRECHT, HOLLAND. 42.3 m., Export Dept. 461 4th Ave.. N. Y. C. Addr. Dr. M. Hellingman, Tech- A Slide Rule Everyone Will Prize nical College. Sat. 11.10 -11.50 am PRACTICAL, EDUCATIONAL, TIME SAVER 6.990 XEME MERIDA, YUCATAN, 42.89 m., Addr. Calle 59, No. 517, "La Voz de Yucatan desde Merida." AS-Tr TIS, seasoned Irregular. ,er alure or " Ininn,InY changes.' , ,. Instructions and Illustrnti",,s of Primary ul,eratinns 6.977 XBA TACUBAYA, D. F., 43 m. clarly printed tin a side of rule for ready ref- MEX., erence teaching.Each rule with a durable pocket 9.30 am..1 pm., 7 -8.30 pm. tarrying case for convenience and Protection Newest! 6.805 HI7P CIUDAD TRUJILLO, DOM. REP., 44.06 m., Addr. Emisoria Diaria de Commercio. Daily exc- Sat. MULTI- A411' and 12.40 4 111làáwllmlainy+a} nr Sun. -1.40, 6.40 -8.40 pm. 1 Sat. 12.40 -1.40 pm. Sun. 10.40 am: sallod,?.n 11.40 am. UNIT bi mphln 6.790 PZH PARAMIRABO, SURINAM. 44.16 Addr. P. O. Box 18. Daily Dual Diaphragm 6.06 -8.36 am., Sun. 9.36 -11.36 am. SELF Daily 5.36.8.36 pm. LOCKING CRSTAL 6.775 HIH SAN PEDRO DE MACORIS, DOM. TILTING We offer ight inch, white wood. accurate slob. , HEAD le with A B. C. D. CI and K Scales. a 20-Pao., REP., 44.26 m. 12.10 -1.40 p m . In a MICROPHONE ¿.f tractions. How to Use Slide Ruie. 7:30 -9 pm. Sun. 3.4 am., 4.15 -6 96 1kin 1 Bak f floe F.xp,nrdes find a two. toned Fars mile of the Declaration of IaM ,codex.." pm., 4.40 -7.40 pm. Top quality for public address and night soitahle for n 1 h,g. and an °.^,age catalog illustrating and leserim g indoor games d mane ...sue' 6.750 JVT NAZAKI, JAPAN, 44.44 m., Addr. club use. Cannot be acoustically overloaded. all five paid here In the "Unite Kokusai -Denwa Kaisha, Two models: MU -2 ($29.50) with two dual State. .,_,i amide 'ter Ltd., 5t)4: Tokyo. Irregular, diaphragm crystal units, and MU -4 ($39.50) with four dual diaphragm crystal units. Black 6.730 H13C LA ROMANA DOM. REP. 44.58 and chrome. Complete with socket and m., Addr. "La Voz de la Feria." 25 -ft. cable. See jobber or write for STURDY BINDERS 12.30.2 pm., 5 -6 pm. literature. for any size Covered with black corru- 6.720 PMH BANDOENG. JAVA, 44.64 m. Re- gated fabricnid. Has ' two lays metal ends with N.I.R.O.M. programs. 4.30 -11 Astatic Microphone Laboratory, Inc. 1mped2 Springpring wire separators. Or 11.30 art.. Also Sat. 9.30 pm: Dept. J -5, Youngstown, Ohio Magazines r be inserted 1.30 am. and removed In jiffy. Licensed under Crush Development Do. Pat,'. 12...591/5. fits R.&T. Radio News, etc... 80c 6.690 TIEP SAN JOSE, COSTA RICA, 44.82 m. 10dies70 fits Popular Men. Addr. Apartado 257, La Voz del m 8áq x51 ¡c fits Reader. Tropico. Daily 7 -10 pm. THE NEW EARCAPS Digest. le. SOC Improve the quality of your head. 6.675 HBQ GENEVA, SWITZERLAND, 44.94 m. phone to give results of dy- Addr. Radio -Nations, namic Immediate Off the air Ambassador. Brrandes.. at present. Kellogg BEAUTIFUL CHRISTMAS CARDS CockonpRadiorar. Solid. rImni 6.672 44:94 m., Featherweight and Professional. - relays Western Electric 'phones. at Wholesale Prices Salamanca, Spain, 7 -9.45 pm. MAay rcan. onef i at. Christmashe e Gift. Assorted Old English color print and engraved 6.672 YVQ MARACAY, VENEZUELA, 44.95 m. Inventor and Manufacturer 21 cards viith etnelopes to match, packed In at- Irregular. Dept. 5 -12 tractive Holiday boxes. parcel post prepaid in V.S. II PAUL JARNAK 68 West 83rd St.. New York City and t'anada. 6.635 HC2RL GUAYAQUIL, ECUADOR, S. A., Guaranteed to please or money back. 45.18 m., Addr. P. O. Box 759. Sun. 5.45 -7.45 pm., Tues, 9.15- (Retail Value 82.10) Your Cost 75c 11.15 pm. Oar 1939 catalog is chock full of Send for catalog containing full descriptions of these 6.630 HIT CIUDAD TRUJILLO, D. R.. 45.25 new Standard Brand Radios for and many other interesting Items. m., Addr, "La Voz de la RCA llmne -Farm -Auto. Over 400 model,. Also hundreds of Electric Appli Victor," Apartado 1105. Daily ances for the home. Celebrating GOLD SHIELD PRODUCTS exc. Sun. 12.10 -1.40 pm., 5.40 -8.40 our 50th Anniversary with Big pm.; also Sat. 10.40 pm.-12.40 am. Bargains. Write for your copy D'lt. RT -12 350 Greenwich St. Nra York today. It's FREE. (Continued on following page) MODELL'S, Dept. 60, Cortlandt St.. N. Y. C. for December, 1938 Please say you saw it in RADIO 8 TELEVISION 505

www.americanradiohistory.com World S -W Stations 1GOMMERCIAL NOTICES (Continued from preceding page) Mc. Call Under this heading only advertisements of a commercial nature are accepted. Remittance of 10c per word should accompany all orders. Copy should reach us not later than the 10th of the month 6.625 PRADO RIOBAMBA, ECUADOR, 45.28 m. for the second following month's issue. Thurs. 9 -11.45 pm. 6.610 YNLG MANAGUA, NICARAGUA. 45.39 A.C. GENERATORS MISCELLANEOUS CISL-CARDS,SWL m. Emisora Ruben Dario. 1.3, NEW 110 VOLT A.C. FANBELT RAZOR BLADE SHARPENER. 100 100 NEAT SWL CARDS PRINTED 7 -II pm. generators for portable power. 8 sixes. shaves with same blade, 25e postpaid. with your name and address sent post- 6.558 HI4D CIUDAD TRUJILLO, D. R., 45.74 m. Howard II. Brown. Edgerton, His. of and Write LeJay Manufacturing, 117 LeJay paid for $1. Bunch samples Except Sun. 11.55 am.-I.40 pm. Building. Minneapolis, Minn. RST Chart for five cents in stamps. 3% INCH TR. 0 -125 VT. A.C. W1BEF, 16 Stockbridge Ave.. Lowell. 6.550 XBC VERA CRUZ, MEX., 45.8 m. 8.15-9 AGENTS WANTED Voltmeter. 0 -10 A.C. Ammeter, 52.75 Mass. each. Heston D.C. 0 -7 and 0 -190 Volt- am. 300% PROFIT SELLING GOLD meter, 2A" with 9 pt. D.P. Switch RADIOS 6.550 TIRCC SAN JOSE COSTA RICA, 45.8 m., Leaf lattera for Store Windows; Free $2.75. Nati. MB27 -4 Stg. T.R.N. Addr. Radioemisora Catolica Metallic 446 North Clark. Thord. 45 P.P. Pack. samples. Co., chassis and IF YOU ARE LOOKING FOR Costarricense. Sun. II am.-2 pm., Chicago. $7.50. 10" MUTER DYN. SPKR. 63.00 wonderful values in a 5 tube radio n. -2 Victor 73" HI -Fi Orthophonie Horn, with dynamic speaker or a 7 tube 6.7, 8 -9 pm. Daily 12 pm., BLUEPRINTS AND DIAGRAMS Mag. and Acoustic Pick -ups, $10.00. superhet 1254 -35. 34 -120. 180-550 6 -7 pm., Thurs. 6 -11 pm. TYPE plus express. $400.00 RCA battery meters. write for our Illustrated folder \VSK1'X:- DIAGRAMS ANY $25.00. Harry Ackerson. six models. Agents can 6.545 YV6RB BOLIVAR, VENEZUELA, 45.84 m., transmitter or receiver and three Ques- Superhet- describing N. .1. handling our line. tions swered full detail $0.3.7. Ramsey. make good money Addr. "Ecos de Orinoco." 6-10.30 11. G. Young. 127 Liberty St.. New "Ham " an apparatus built to order. WE OFFER SUBJECT TO PRIOR pm. llarry D. Ilooton. Hender- York. \C8KPX- sale 7 m.m. lacquered cable used by 6.520 YV4RB VALENCIA, VENEZUELA, 45.98 m. son. W. Va. an cable the (government. It is ideal SHORT WAVE COMPONENTS II am.2 pm., 5 -10 pm. for high voltage. low current service. CORRESPONDENCE COURSES such as used in radio transmitters. TilE BEST FOR LESS IN ('RYS- 6.516 YNIGG MANAGUA, NICARAGUA 46.02 amplifiers. etc. It is a special steel tal mikes. $7.95 and up. Money hack m., Addr. "La Voz de las 500,000 USED CORRESPONDENCE very heavy rubber if not satisfied. Mangan Electronic Educational Books Sold. wire. 20 gauge, with Lagos." 8 -9 pm. Courses and 12c a foot. Special Industries, North Warren. Penna. Rented. Exchanged. All subjects. insulation. Worth price 50 ft. $2.00. 100 ft. $3.00. 6.500 H I L CIUDAD TRUJILLO, D. R., 46.13 m. Satisfaction guaranteed. Cash paid for N. Y. Gold Products. SHORT WAVE RECEIVERS 12.10-1.40 used courses. Complete details and F.O.B., Shield Adir. Apartado 623. 350 Greenwich St.. New York City. bargain catalog free. Send naine. USED DOERLE'S, D -38. 11S -5, 7C. pm., 5.40.7.40 pm. Nelson Company, 3487 Manhattan reconditioned by factory. 40% off. See DE LOS CABALLEROS, Building, Chicago. Television for 6.480 HILL SANTIAGO PATENT ATTORNEYS January Short Wave & 46.28 m., Addr. Box 356. description. Kusterman. 68 Barclay D. R., INSTRUCTION INVENTORS -PROTECT YOUR St.. New York. 9.40-11.40 am., 7.40 -9.40 pm. rights before disclosing your invention 6.470 YNLAT GRANADA, NICARAGUA, 46.36 RADIO ENGINEERING. BROAD - to anyone. Form "Evidence of Con- SONG POEMS WANTED casting. aviation and police radio. ception"; "Schedule of Government m., Addr. Leonidas Tenoria, "La ervicing. marine and Morse telegraphy and Attorneys' Fees" and instructions WANTED OIIIGINAL POEMS. Voz del Mombacho." Irregular. aught thoroughly. All expenses low. sent free. Lancaster. Allwine & Rom- songs for immediate consideration. Catalog free. Dodge's Institute, Colt mel. 436 Bowen Ituilding. Washington. Send poems to Columbian Music Pub- 6.465 YV3RD BARQUISIMETO, VENEZUELA, Toronto. ir- St.. Valparaiso, Ind. l) i . lishers, Ltd.. Dept. K49. Can. 46.37 m. Radio Barquisimeto, regular. 6.450 H I4V SAN FRANCISCO DE MACORIS D. R., 46.48 m. 11.40 am:1.40 FOR SALE NON COMMERCIAL) 3 wÓRD pm., 5.10 -9.40 pm. 6.440 TGQA QUEZALTENANGO, GUATEMALA, Under this heading we accept advertisements only when goods are ffered for sale without profit. 46.56 m. Daily 6.10 -10.10 pm., Sun. Remittance of 3c per word should accompany all orders. Copy should reach us not later than the I -3 pm. second month's issue. 10th of the month for the following 6.340 HIIX CIUDAD TRUJILLO, D. R. 47.32 m. tubes 7.40 -10.40 am., dally 12.10- 1 11.Ú'E SEVERAL GOOD I'M 5" fitting, receiving. price $l.-,.Ito. transceiver complete with $10.00. Su). dynamic speakers in the original fac- Butler. 75Ur Balmoral Place. Winnipeg. Price $20.85 elsewhere. You save 1.10 pm., Tues. and Fri. 8.10 -10.10 tory cartons that make very Fit mikes. Man.. Canada. $10.85. Interested? Write: James C. pm. I want to dispose of these units at Moulton. 4912 Quebec Street, N\V. COMPLETE NATIONAL RADIO D. C. PERU, 47.33 m., Addr. La Voz factory cost as I no longer use this Institute course -Radio Servicing. Washington. 6.335 OAXIA ICA, type mkr. in our equipment. Will Sound Pictures. Public Address. Text SUPER -7 $24.00. SKY CHIEF de Chiclayo, Casilla No. 9. 8- ship COD if your offer is satisfactory. books and experimental equipment. $24.0; II pm. Paul C. Mangan, Box 2218, No. Warren. $20.00 cash. F. Aldridge. 1228 Shepard 0. Bing 12 $59.00 [ latestte Penna. St Petersburg. Va. model SX -16 Super- Skyrider with 6.324 COCW HAVANA, CUBA, 47.4 m., Addr. $79.00. WOAILt. Butler. 31o. P. O. SELL COMPLETE HAM OUTFIT FOR SALE: BRAND NEW DESK crystal La Voz del Radio Philco, 90 watt transmitter with power supply type 50 watt phone 80 watt note 1937 1HAYNES CLIPPER. PFA- Scx 130. 6.55 am. -12 m. Sun. 9.55 and meters, 5 tube receiver both abso- 5 -10 -20 meter transmitter. fully guar- feet condition. $20 prepaid. Max an.-I0 pm. lutely complete and In excellent condi- anteed, at reasonable price. Illustrated Welton. 31 E. 24th, Holland. Mich. tion. Price $40.00. F. W. Freutel. 840 description furnished. Alvin Abrams NEW MASTER TELEI'LEX. ALSO 6.310 HIZ CIUDAD TRUJILLO, D. R. 47.52 m. S. Kenlston Ave.. Los Angeles. Calif. (W2DTT) 20 Laurel 11111 Terrace. Standard number one. instruction Daily except Sat. and Stun. 11.10 FEDERAL ORTHO -SONIC POWER New York City. course included. half price. Gertrude an.-2.25 pm., 5.10-8.40 pm. Sat. unit. Two rectifiers. good chokes and CO 5- METEI( ENTHUSIASTS - Salz. 2614 Greenmount. Baltimore. 5.10 -11.10 pm. Sun. 11.40 am.-I.40 filter. Suitable for experimental. trans- Brand new Lafayette model 19" Maryland. pm. 6.300 YV4RD MARACAY, VENEZUELA, 47.62 m. 6.30 -9.30 pm. exc. Sun. 6.295 OAX4G LIMA, PERU, 47.63 m., Addr. Apartado 1242. Daily 7.10.30 pm. TRUJILLO CITY, D. R., 47.77 m. 35 WORDS. INCLUDING NAME AND ADDRESS 6.280 HIG NO ADVERTISEMENT TO EXCEED 7.10 -9.40 am., 11.40 am.-2.10 pm., is intended solely ted from any reader In any one issue. All dealings Sate in this department is not sold. It Remember you using the U. S 3.40 -9.40 pm. for the benefit of our aders, who wish to buy MUST be above board. onographs. cameras. bicycles. mail in all these transactions and therefore you are bound exchange radios. parts. S. taws. Describe anything you offer 6.270 YVSRP CARACAS, VENEZUELA, 47.79 m., portinreceivegoods. books. magazines. etc. the U. Postal fellow money for those announcements. we can. byaccurately and without exaggeration. Treat your Addr. 'La Voz de la Philco.' As we for any statements made by the en the way you wish to be treated. ot responsibility We welcome ggestions that ill help to make this de. Daily to 10.30 pm. renders. one advertisement can be artment interesting and helpful to o readers. Use these columns freely. Only 6.255 YVSRJ CARACAS, VENEZUELA, 47.18 m. us not plater than the 10th of the month for the second following month' issue. Copy should reach TRUJILLO, D. R. 48 m., \%'ILL 6.243 HIN CIUDAD WANTED: CODE INSTRI'(T1ON WANTED: SMALL SHORTWAVE TRADE $139 "DEFORESTS Addr. "La Voz del Partido Dom - Have auto for quantity Training" radio course. practically machine or typewriter. broadcast and transceivers 60 back issues Radio iricano." 12 n.-2 pm., 6 -10 pm. Israel. adio and new tubes. complete. and radio or will pay cash. .Tack of new radio parts News. for good low power phone trans- 319 Peshine Ave.. Newark. N. J. Russell 35 -37 -34th St.. As- 6.240 ZGE KUALA LUMPUR, FED. MALAY New York. mitter, 10 to 80 meters preferred. Malayan - WANTED: 16MM PROJECTOR. toria. Tang Island. Clifford Jenkins. Clayton New Mexico. ST., 48.1 m. Addr. TUBE Radio Society. Sun. Leks do not matter but must work HA\-F. ONE AND TWO WANTED: SET ANALYZERS. A.mateur 100%. 100 volts A.C. Have plenty radios. crystal sets. parts. Want rifles. Tues. and Fri. 6.40 -8.40 am. etc. All Haynes. Doe Run. meters. what have you. I have good radio parts. stamps, tubes. radina. etc. John 110 V. A.C. motor. Also 48.12 m., Also p S\\9, Missouri. 1/3 H.P. 6.235 HRD LA CEIBA, HONDURASHONDURAS, letters answered. 3ajestic A and R eliminators. dy- cards. D. Witman. Peters s Place. Red COURSE Addr. ' La Voz de WILL SWAP $112 N.R.I. namic speakers. Majestic receiver Sun. Bank. N. 7. specializing In communications com- (A.('.). Nelson A. Hitchcock. Williams- 8 -11 pm.; Sat. 8 pm.-1 am.; WANTED PEN -PALS IN FOR. plete with all extra booklets and x- town. Pa. 46 pm. to exchange snap shots perimental material for Sky Buddy. elan cavalries HAVE 15 COPIES READER'S VA6.9.3'-ER0 A, VENEZUELA, 48.15 m. and stamps. L. S. Finnegan. 723 5. Super Clipper, or better communica- I 6.225 YVIRG Box Digest. 2 valuable volumes (completely pm. Federal Ave.. Mason City, Iowa. tions receiver. Henry Greenawalt, illustrated with mannikins) Medical 46, Pa. U.S.A. 3fountrille. Instructor for the People." 7 Cana- 6.210 SAIGON INDO -CHINA, 48.28 m., WILL SWAP 7 INCH UTAH DY- SWAP: VOLUME NO. 1. NO. 2 dian and Mexican coins. Want Ifimm - Addr. Radio Boy -Landry, 17 Place namic speaker. new receiver tubes of Official Radin Servire Manuals. never Mtn or what? W9SZW. 3815 Congress A. Foray. 4.30 or 5.30 -9.15 em. many apes. meters. metal receiver used. value E8 for A.C. record player. Street. Chicago. Illinois. 163131 cabinets. audio and power transform- 5-8 watt amplifier. Irwin YVSRI CORO, VENEZUELA, 48.32 m., 300 Ma. 3000 V. 160M CRYSTAL AND HOLDER. 6.205 ers. Wanted-a folding camera. tuera. or 20 Hy. National transformer. Brownscope Roger Leyba, care A. Francis McAllen. WIFZX. 37 Oak- filter choke. F. A. i.f. Addr. St.. Natick. Pa. microscope. xmitting. l'erg parts. 350V Urbina y Cia. Irregular. land Mass. Are.. Tyrone. transformer. I want antiques. antique WANT 50 WATT OR MORE ?CANTED: GOOD TYPEWRITER Jewelry or what? W9TMQ. 3860 6.200 HIBQ CIUDAD TRUJILLO, D. R., 48.36 modulator-Have an E flat Alto Sax- in good condition. 8911 swap violin Harrison Street. Chicago. 111. n. Irregular. Iras not hem ophone in exchange. Will consider course practically new. 56Ts. other trades. F. A. Kramer. Hamburg. tube. Costs $36. Or what have you? WANTED, 1 OR 2 EIMAC 6.190 TG2 GUATEMALA CITY, GUAi., 48.4. 002 Ave.. crystal mike. 40M. crystal above 3125 of Electr. Iowa. Charles Rosieh. Jackson Have m., Addr. Dir. Genl. Irons. N. Y. K.C.. other trans. equipment. Mon.-Fri. WANTED: CIRCUIT DIAGR4YIS Emerson motor -generator. 6 boxes 12 Commun. Relays TGI eta. for a RCA Radicala 20. Also Inter- WANTED CAMERA ALSO PHOTO gauge shotgun shells. other things to 6 -11 pm., Sat. 6 pm: I am. Sun. ested in Radlola 20 parts. etc.. and equipment. Trade power parks. dr- trade. H. Ruehrie. 722 Penna.. Gary. 7 -II am., 3 -8 pm. 1923 -1928 volume of RCA Victor namic speakers. prover transformers Ind. Lurskt. 15 Grove and Short Wave Crafts. Bernard lilnes. 6.115 HIIA SANTIAGO, D. R., 48.5 m., Addr. service notes. Fred WILL TRADE FOR STANDARD Terrace. Irvington. New Jersey. 4012 W. 10th Avenue. Gary, Indiana. P. O. Box 423. 7 am.-5 pm. radio equipment a fine old violin. NO. 3. OFFER 214 -5 METER. 4 TUBE HAVE RIDERS MANUAL Perfect condition. Case included. Ad- 6.156 YVSRD CARACAS, VENEZUELA, 48.71 m. transceiver. carbon mike. $20 R.C.A. 2 Official Radio Manuals and all other dress letter stating cash offer or de- 1 am..2 pm., 4 -10.40 pm. record player. for exceptional camera kinds of radio parts. Will trade for scription of equipment to Post Office or National SW3 wills accessories. or ohmmeter or tube tester. Abe Och- Box 651, Alfred. N. Y. 6.153 HISN MOCA CITY. D. R., 48.75 m. 6.40- superhet. Dick Gearhart. 920 School. atein, 335 E. Lewis St.. Fort Wayne. 9.10 pm. Indiana. Penna. Iod. (Continued on following page)

RADIO & TELEVISION 506 Please say you saw it in RADIO & TELEVISION

www.americanradiohistory.com 49 Met. Aoadcait iland BARTER and EXCHANGE FREE ADS (continued) Mc. Call BAVE STAMI' COLLFATION EXCHANGE CODE MACHINE WILL SWAP SPRINGFIELD .22 6.150 CJRO WINNIPEG, MAN., CANADA. cataloguing over $150.00. also many tapes and key. crystal controlled C.W. rifle with peep sights for a good used 48.78 m., Addr. (See 11.720 roc.) duplicates, Jirtyprint duplicating set, transmitter complete. Ford auto radio, portable typewriter. Q1t9. Everett and many radio parts. Want radio dynamic speakers. power and A.F. Twining, 206 Quincy St., Springfield. Deily 6 pm.-I2 m., Sun. 5 -10 pm. parts or what have you? W21N0, transformers. variable condensers. Mass. 6.150 ZPI4 VILLARRICA, PARAGUAY, 48.75 1140 College Ave.. New York City. Plug-in coils. Otis Pierce, % Box Alexandria. La. SWAP. NEW TUBES Olt CASH m. 5 -6 pm. 6 TUBE BATTERY RADIO. AUDIO 11.,1. for old automobile and motorcycle 10,000 stamps. WANTED: 6.147 ZRD DURBAN, SOUTH AFRICA, 48.8 oscillator. Want radio RADIO CATALOGUES license plates front every state and course, books, also parts and sets SW. for club rooms. Jackson Short \Pave country on earth. Trade radio net for m., Addr, (See ZRK, 9.606 inc.) A. Hartman, 5713 -5th Are.. Brook- League. 616 Fourth St.. Jackson, old automobile. What say? Anthony Daily exc. Sat. 11.45 pm.-I2.50 lyn. N. Y. Mich. Shupienus, Newport. N. J. am.; Daily exc. Sun. 3.30.7.30 WANTED FOR CASK OR T1tADE: DESIRE TO TRADE STAMI' COL- WANT GOOD SHORT WAVE am., 9 em.-3.45 pm.; Sun. 5.30 -7, Portable radio set to work speaker. lee ion of 2000 varieties, hundreds un- converter with plug -in coils, Will pay 9.11.30 am., 12 n:3.20 pm. Also need not be in working condition. used. for good S.W. receiver a s "ItSlt ash. Carl V. Seibert. Jr.. 77 Main 4.5 am., 3rd Sun. of month. tubes and batteries not required. Clipper ". "Doerie - or others. Street, Oberlin. Pennsylvania. Voss. Michael Cooney. Box a 237. Ft. Sato K. 606 Onderdonk Ase.. TRADE 5 METER 6.147 ZEB BULAWAYO, RHODESIA, S. Nan Texas. TRANSCEIVER Brooklyn, N. Y. Houston P. 0.. Antonin. complete, power supply, microphone. AFRICA, 48.8 m. Mon. Wed. HAVE A l:OOI) VIOLIN WITH WANT ANY TYPE TEST EQUIP - speaker and tubes (76.41). 30 watt and Fri. 1.15.3.15 pm.; tues. 11 $7.50 bow, drawing outfit. radio mein. Will trade: 3 -4 tube AC -Dt' 80 meter (2W transmitter. also other em. -12 n.; Thurs. 10 am.-I2 n. Parts. Want Sky Buddy or goal S.W. battery s -w sets, radio parts, b¡ h.p. parts; want short wave receiver. Send Sun. 3.30.5 am. receiver or transceiver. Eugene Tate. motor with drill press, a chuck. particulars. James Dolan. Box 655. 316 W. College Ave., York, Pa. Luigi D. 31ingace, 89 Elm Street. Woonsocket. lt. 1. 6.145 HJ4ABG MEDELLIN, COL., 48.79 m. II am: SWAP: RADIO SET PARTS. West Newton. Mass. WANT A ('ALL BOOK MAGASINE 12 n., 6 -10.30 pm. electric hair clipper, battery charger. SWAP: HR() SENIOR COMPLETE, not over a year old. llave tubes and 6.140 W8XK PITTSBURGH, PA. 48.83 m., Addr. binoculars. used course in freehand perfect condition. for R31E69. 5X17 other radio Darts to trade. All lettera drawing. valuable «leer antlers. Hallicrafter, Super Pro. Must have answered. E. Trued. Westinghouse Electric & Mfg. archi- Paul Tribune, tectural compass for 120 bass piano noise silencer and broadcast. William Kansas. Co. Relays KDKA II pm. -12 m. accordion. letters answered. Quigley, 102 Ave. S., Brooklyn. N. 3. All C. TRADE: 8 TUBE MILLER SUPRA. 6.137 CR7AA LAURENCO MARQUES, PORT. E. Lauda, 67 Everett St.. Everett. Mass. 5E1 STUC SUPERHETERODYNE het with 12" speaker. four switch AFRICA, 48.87 m. Daily 12.05.1, HAVE ALL KINDS OF RADIO abort wave set. has beat oscillator, 12 bands, good construction and results; 4.30 -6.30, 9.30.11 am., 12.05 -4 parts, short wave parts. Willl ex- inch dynamic speaker, 4 sets coils practically new, quality football equip - pm., change same for rifles or hunting covering 10 to 144 meters. Trade for also magazines. radio stuff. for Sun. 5.7 am., 10 am. -2 pm. equipment, Joseph Bakutis, 794 good film pack or Graflex autera. wCtnt;hat have you ? Fred Gehricke, 2016 6.133 XEXA MEXICO CITY, MEX., 48.93 m. Quinn iplac Ave.. New ((aven, Conn. D. Vinegar. 8410 Dubay. Detroit. Palmetto Street. Brooklyn. N. Y. Mich. Addr. Dept of Education. Daily WANTED LATE 8 ", 10" Olt 12' HAVE NEM' 163131 3loviematic 8 -11 em., 2.30.4 pm., 7.30 pm: records of all kinds not os er two WILL TRADE A BANJO -UKE camera, new electric razor, book.. 12.45 am. Sun. 1.30 pm.-12.45 am. years old. have radio parte and tubes for a good condition pocket radio. stamps, other items. Want all photo- to offer In trade. Paul Bahr, 1205 Banjo- tike is in goal ondition. graphic items. enlarger, spectlY candid 6.130 VP3BG GEORGETOWN, BRIT. GUIANA. W. 10th St.. Marion, Ind. Floyd Snssaman, Box 104. Colby, Wis. camera, or ? Michael Glanfrocco, 004 48.94 m, From 5 pm. on. BOSCH AUTO It:\DIO LIKE NEW SW.\l' JR. CANDLER CODE L non Ave., Prov., R. I. 6.130 TIEM SAN JOSE. COSTA RICA. 48.94 m. Itadlula 18: Speaker; new tubes course good condition. also Candler TIRADE RADIO l'ARTS FOR 2 Kellogg l'wr and rase speed hand course. Speed -X - button carbon mike and transformer. "El Mundo" Apartado 1049. II l'k: guitar Unisex Al, camera : 2-136 IF Trans automatic key or all kinds of radio Electric pickup wanted. ¡lase P.P. am. -I I pm., Sun. 10 am. -6 pm. \\'anted, good communications receiver parts for volt-ohm- milliammeter or transformers and speakers, battery 6.130 CHNX HALIFAX, N. S. CAN., 48.94 m., Ed. Prendergast. 736 l'ark flees Instrurtngraph. S. (lark. 1119 Yale tube tester, Jewell 2 meter. Jefferson Ave., Cincinnat 1, Ohio. tube rejuvenator. P. Long Beach. N. Y. etc. J. lt. (teed. Addr. O. Box 998. Mon.-Fri. 218 W. 3. Durango, Colo. 7 am: II.15 pm., Sat. II am: HAVE: PHILCO MODEL. 00. HAVE RADIO AND ELECTRIC Notre Dame water pump. W'urtltzer parts, Majestic service manuals. books. CLEANING OUT HUNDREDS OP II pm., Sun. 12 II.I5 pm. Re- n: Guitar. etc. Want Tektites haut spe- hand striven A.C. generator. stamps. radio parts. also 5 tube s r super. lays CHNS. Gfal. or t Joseph Kubik. 37 Pine St.. electric experiment parts. Trade for Send for List. Need hiders Manuals. 6.130 LKL JELOY, NORWAY, 48.94 m. II am: t. Ilarringt mn. Mass. a small transmitter. Sky Buddy or D'pewriter, testing equipment. auto SWAP- .S.t .22 SHOT other radios preferred ? What have "A" eliminator. wrist watch parts. 6 pm. \'AGE SIX your Penna. or Stanley. bolt action rifle. Weston 6 -3 an- Irvine Clifford. Linwood. 2748 alcade, Detroit. 6.125 CXA4 MONTEVIDEO, URUGUAY, 48.98 alyzer. ITTL tube checker. jli Thomson WILL TRADE NATION \I INST 31 eh ca n. m., Addr. Radio Elettrico de 0.511 A.C. ammeter. Power supplies radio course and Chicago Tech. Build- S\'AI' DEFOREST ItA 1010 COURSE 411 Montevideo , Mercedes 823. IO and many other parts. \C nt ham ers course. Want high power trans- Gann lessons) for typewriter, W'1KS.1. superheterodyne am. -12 n., 2 -8 pm. equipment. 108 Rooky Ave.. mitting equipment, receiver. transceiver. 20 gauge shot \Valerbury. Conn. most tone to 10-3 meters. J. T. Kelly, gun. photos pickup. plump turntable 6.122 HJ3ABX , San ? BOGOTA, COL., 49. m., Addr. La S\\'AI' A DOUBLE ILI'T'rON 6 N. St.. I eIro, (alit. or what Will swap S \ \L carda 100%. Henry Bodkin. 118 North Voz de Col., Apartado 26 -65. 12 microphone and stand. have a Uni- SW.\l' 150 PAIRS HANDMADE Jr.. Main St.. St. 31 ary's. Ohio. n. -2 pm., 5.30-t I pm.; Sun. 6 -11 versal 'lentil -mike good as new. Also woolen shoe charms. about 1 inch pm. a 5 meter receiver. Looking for ham long, many sold at 25 cents pair. ((AVE STAND' AWII'II, 1.000 short-wave receiver. \\'ILDD, 64 Want portable typewriter, Leica min. different stamps. 3.1100 assorted, Ma- 6.122 HPSH PANAMA CITY, PAN., 49 m., Zeigler St., Roxbury, Mass. Gotten. woakarvers tools. bicycle. or jestic super -dynamic speaker, Model Addr. Box 1045. 10 am. -I pm., hat have you t Otto Strand, 2854 G -2, set of roils 914 TRAIE EIGHT VA It1ABLE l'ON - -539 meters. radio 5 -11 pm. densers from Atwater-Kent radios. East l97th St.. New York Illy. parts, magazines. Want S.W. receiver or John Fitzpatrick, 18 First Street, 6.120 W2XE NEW YORK CITY, 49.02 m., "Kuprox" dry reel cher for ,halt WANT USED CANDLER SYSTEM. Addr. Bave Weston switchboard roltntetei complete nd recent, for 852 by ItCA Port Reading. New Jersey. Col. B'cast. System, 485 Madison 0 -11 -1311 cost $46 -for crystal and I'M dynamic speaker, or what do S\ \'al' D. It. MIKE TITANS., ANTI - 10.30 Ave. -11.30 pm. holder. any band. or ? Albert Winniett. y"ou need? Mangan. Box 218. North capacity swritches. jacks, roil form 6 6.117 XEUZ MEXICO CITY, MEX.. 49.03 m., 237 -27 Davenport Ave.. Bellerose, Warren. Penna. prong. 20 ma. relay. 3 in. mag. speak- WANT l'OT'rERY. er, engineering, drawing. botany, ehem- Addr. 5 de Mayo 21. Relays INDIAN istry. geology. 6 relies, old guns. swords, daggers. deer college texts for UST', XEFO 1 -3 am, ILA VE HORSE HEAVY DUTY head. old coins. statuary, vases. old goal condition. M. Byrne. 515 N. inboard (narine engine: also Johnson 15th, ]toise. Idaho. 6.115 OLR2C PRAGUE, CZECHOSLOVAKIA, twin outboard and approx. 100 late prints. plants. Have banjo, Taxidermy 49.05 m. (See 11.41 bac.) radio magazines all different for courses. guitar, banjo -uke. fossils, WANTED sum! WAVE SET OR power tools or radio minerals. Indian cents, plants. Iargt parts. Hase stamp collection, 0.000 6.110 GSL DAVENTRY, 49.1 equipment. H. ENGLAND, m., Hohl, Jr., 609 E. Market. Sandusky. list. Stanley l'ylel, 5025 Ogden Ave.. foreign and U.S. Also have most any- 6.20 -8.30, 9.20 -11.20 pm. Ohio. Cicero. Ill. thing in the chemistry line. What do you want? James Starner. 141 Lewis 6.110 XEGW MEXICO CITY, MEX., 49.1 m., HAVE ROOKS. ELECTRIC SHAY WANTED 3 OR 4 TUILE A.C. short wave receiver. Will cash to Street. Phillipsburg, N. J. Addr. La Voz de Azteca er. movie camera and projector, field pay Aquila best offer. all letters red. WANT-RADIO (LOOKS desde Mex., glasses, photo supplies, lots other AND Apartado 8403. Re- Items. What have you? Let's swap Lewis Mniteni, 519 21st., Union City. courses. Bave stamp collections, min- lays XEJW II pm. -I am. lists. M. Epstein, 2953 Ruckle St.. New Jersey. ing and cartooning courses. camera. 6.110 VPB COLOMBO 49.1 m. Indianapolis. Ind. HAVE CRYSTAL MIKE TABLE "Citandu" $2.50 magic outfit. also CEYLON, unused "Kick- Back" marble game. Daily 7 -9.330 am; Sun. 6.30.9.30 am. TRADE EASTMAN KODAK "SI'E: stand, telephone to Ike. "19" tube. s. w. rec. using 24 -27. Want 211. T20 Wayne Beavers, B.F.D. 1, Forest rial" No. 620, Lens F:4.5, shutter I City. 6.108 HJ6ABB MANIZALES, COL. 49.14 m., Addr. see. to 1/400, with rase. valued or what have you Frank Oazarek Missouri. P. O. Box 175. Ìvlon.Fri. 12.15- $47.25. like new. for camera with 1124 W. 18th l'1., Chicago. Ill. WANT: CRYSTAL MIKE CLASS It for 4 1 pm.; Tue. and Fri. 7.30.10 pm.; coupled range finder, will add cash WANTED: C.S. COMMEMORA- -46's. Have Shure (3A) D.B. Sun. 2.30-5 pm. difference. Vincent Cernis, 1515 S. tires, collections, two tube A.C. short mike, class A prime unit 30 watts 49th Court, for what bare you In a Cicero. Illinois. Wave Set Trade: radio parts. tubes . class B 6.100 YUA BELGRADE JUGOSLAVIA, 49.18 \\ ill exchange stamps. post cards with l all A -11. Have many parts. Elmer TRADE "MODERN RADIO HOOK - Saxe. m. 12.45. 3[.30, 4 -8 am., 1.6 pm. ups". "Principles of Radio Com- other rollectors, especially foreign 1932 Faye ltd.. Akron, Ohio. Elmer Braswell, 1581 Melrose Dr., TRADE-I'M 6.100 BOUND 49.18 m., munications" by U. S. Army. 'Appli- illtELI.A TEN'(' 7:9. WIXAL BROOK, N. J., cation of Electricity to Atlanta. Ga. folding steel camp bed. new radio Addr. Natl. Broad. Transmission" Co. (4 volumes) by Bell Telephone. for HAVE CRYSTAL RADIO, 2000 parts for SW-3. Ultra - Stratosphere 6.100 NOUMEA, NEW CALEDONIA, small set. trans. :'tat, anything. ohm eat phones, rhassis parts (controls, 10, or Sky-Buddy. Synchronous vi- What say! Jim Redmond, 88 239 Antennatrol, brator, power transformer for handset. 49.18 m., Radio Noumea, Addr. -48 tubes. rolls:. wire, bat- St.. Itellerose. L. I.. N. Y. teries. books, etc. Want good photo L. T. l'atterson, 32 H. Street. Salt Charles Gaveau, 44 Rue de l'AI- developing outfit. 3lurray Stielnls. 99 Lake City. Utah. ma. 2 -3.30 am., exc. Sun. and SWAP: CLASS It MODULATOR Featherbed bene. Bronx, New York. KOOK- MATCH unit. a COLLECT ORS - Mon. Chassis T 13'. includes built - Do you in screen voltage supply, Thordarson WILL TRADE ARGUS CAMERA swappers. have any from the flots city P Ilowr a 6.097 ZRK KLIPHEUVEL, S. AFRICA, 49.2 m., 111175 multi -match output trans- model AI, and 35 non. tank for Tele- about swap for some plex or Instructograph with your town and state on them? Addr. S. African Broad. Co., former. Thordarsott 831)21 500 ohm code marline line to grid and tapes. E. H. Jackson Jr., 932 N. Griffith, 815 Highland. Johnstown. Johannesburg. Daily 12 n.-4 pm., input transformer. 2 Tung -Sol 616G. \%'rite: W9'l'ME. 15th Street. Augusta. Georgia. Penna. 12 n. -3.20 Sun. pm. 2901 N. Kilbourn Avenue, Chicago, SEVEN TUILE PI LILCO 3101)EL WILL SW'.\l' "RADIO READING III. 20 with poor tubes, two pairs of Union COURSE" about fundamental radio. 6.097 ZRJ JOHANNESBURG, S. AFRICA, 49.2 skates. 22 firearms. Want good make 100 formulas, book on making and m. HAVE ONE CYLINDER GAS EN- using dry Addr. S. African Broad. Co. gine in perfect running order also of bellow (plateI caillera. lens 200- batteries. Books entitled Deily exc. Sat. 11.45 pm.-I2.50 large variety 2, ib the second. John Nicholas, Ut. I. "Toasts and Speeches" and "Business of radio parts. Would Letter Writer Margaret Schleicher. am.; Daily exc. Sun. 3.15.7.30, Ilke to get low power transmitter or Box 190. \ tiramene Ave., Mountain ". View. California. 930 Hamilton Blvd.. Peoria. Ill. 9.11.30 am. (Sat. 8.30-11.30 am.) SW receiver or what ? A. Struainskas 6935 S. Sun. 3.30 -4.30 or 4 -5 am., 5.30.7, California Ave.. Chicago. Ill. WILL TRADE HIGH SPEED WANT PHONOGRAPH RECORDS (send list). l'.S. prer.tncels. 9 -11.30 am. STAMPS FROM AIL OVER THE electric drill, Va" cats. for what have and you. Also large number tubes. printing equipment (fonts of type. globe, mint, used. Plenty of pre - radio H. It. Ellis, 120 Se. Cherry St., etc.). Have magazines. records, books. 6.095 JZH TOKYO, JAPAN, 49.22 m., ancels, triangles. constitutions. etc. Addr. Issues from all continents. Richmond. Va. Underwood typewriter, stanmps, radio (See 11.800 mc., JZJ.) Irregular. Will swap stuff. etc. Walter McIntosh, for receiver going up to 10 meters. WILL TRADE: HAMMAIILUN I) Jr.. 8 3. Weiss. 547 St., Summer Street. Melrose. Mass. TORONTO, E. 101 Cleveland. dual 140 mmfd. condenser code 6.090 CRCX CAN., 49.26 m., Addr. Ohio. MCI) -140 -M and lots other parts, l':\NADI AN (AMS. ATTENTION. Can. Broadcasting Corp. Daily SWAP: for radin equipment. V. Gabin, 1738 National S\C5, Orr., Spy.. coils. spier.. COMMUNICATIONS ILT. A. 7.45 am. -5 pm., Sun. 10.30 am: superhet tunes 11 -565 meters. ready N. Newkirk St.. Philadelphia. Penna. radio course, Sprayberry's 12 n. for operation; allwave handawitching SET INTERNATION- Mechanics of Radio, voltage tables. EXCILANGE 1938 Candler Jr. Code course. Will superhet kit : radio parts. books, al Correspondence School advertising trade for Hallicrafters revr. Top 6.010 ZBW2 HONGKONG, CHINA, 49.26 Tsn.. magazines, test equipment for portable books. full morse in 6 volumes, for Addr. P. O. Box 200. typewriter. Stamp for swap shape. Marsden, VE4AOZ, Mtlo, Irregular, -list. John amateur radio equipment or rode Alberta. J. Vilkae. 1515 South 49th Court, course. Describe fully. R. L. King. (Continued ori following page) Cicero. Illinois. 308 West 18, Austin. Texas. (Continued on following page) for December, 1938 Please say you saw it in RADIO 5 TELEVISION 507

www.americanradiohistory.com and FREE ADS (continued) World S -W Stations BARTER EXCHANGE (Continued from preceding page) TRADE - MARVEL ELECTRIC TRADE 250 WATT AND 210 SWAP RADIO l'ARTS, It -ELIM- Mc. Call shaver for what have you. F. Vieweger. tubes, high voltage variable condenser. inaton and radios for what have you. 6.083 VQ7LO NAIROBI, KENYA, AFRICA, 49.31 1411 S. 17th St.. Manitowoc, Wis. Thordarson transmitting receiving Roscoe B. Smith. Jr., 4409 W. 25 St.. m., Cable and Wireless, transformers. filter chokes, power am- Little Rock. Ark. Addr. HAVE DAYRAD TUBE TESTER. plifier. Want Patterson preselector 852 Ltd. Mon., Fri. 5.30.6 am., 11.15 8 tube battery set and a Readrite WILL SNAP SEVERAL UNCUT tubes. C. D. Larimore. W9BBS, 409 am. -2.15 pm., also Tues. and model 710\ analyser. Want a gout smoky Arizona topazes for any thing East 11 St., North Platte, Nebr. Thurs. 8.15.9.15 em.; Sat. 11.15 used 11K20 and a 1250v. power -supply radio. or whet else am I offered? or what have you. Write. John WANTED: USED PARTS FOR B Would like copies of Broadcast News. am..3.I5 pm.; Sun. 10.45 em: IVonack. Box 89. Dlnunitt, Texas. eliminators, 1933 -37 Radio Band- Wayne Dickey, Wintersburg, Arizona. 1.45 pm. books.oks. tete. used radio parts and HAVE HEAVY -DUTY RCA TRADE: AUTOMATIC CODE exchange 6.081 YVIRD MARACAIBO, VEN., 49.32 m. 6.11 SW radios, for cash. Will xfrmr 2 -755x. amp. wdgs. 1 -450- teacher, Keystone 16MM machine diagrams. science maga- l'/ Pm. set uf Meissner short wave circuit QSL's. 0 -450v. 100 mile wdg. Goal for small with lllm, zines. Want small xmitter. IL (/. coils. Wanted: 40 meter crystal. trans- xmttr. Will trade for wot have u? 6.080 W9XAA CHICAGO, ILL, 49.34 m., Addr. M okay. Donald ». Alta. mitter parts, receiver- or what have Paul Bahr, Marion, Ind. Chicago Fed. of Labor. Relays you? John J. Rupert. RED-4. Jack- TRADE: COOKES ItADIO AND WANTED l'IIOTOGRAI'llll' WCFL irregular. son. Ohio. Auto Electrical courses. old tube col- equipment and old mechanical maga- lection. AtwateKent service manual. zines. Have Zenith 6 tube auto radio 6.079 DJM BERLIN, GERMANY, 49.34 m., WILL SNAP "CHARLES ATLAS" 201 VTI and other dynamic tension health course, orig- old 200. tubes and aerial all ready to install. John Addr., Broadcasting House. Ir- things. \\-am some U.S. stamp collec- Sawyer, Tribune. Kans. inal cost $35.00. Want radio course. Box 109, 1t.2. regular. typewriter or what have tions. R. W. Dieter. SW radio, hiver. Wis. l'OIIRESPONDENCE IV ANTE I) 6.077 OAX4Z LIMA, PERU, 49.35 m. Radio Na- you? Robert Jones. 201 Walnut Street, Blue with all foreign countries. Witt swap Resternport, Md. TRADE WESTERN ELECTRIC' stamps and postcards. All letters an- tional 7 -11 pm. CORE carbon microphone for quartz crystal swered. W. W. Hollister. Clear Lake. 6.075 VP3MR BRI. GUIANA, TRADE-- MEISSNER IRON 3.500 GEORGETOWN, beat nac. all ground for somewhere between Iowa. C. S. A. I.f.'s, 450 ke., -freq. trans., he In good 49.3i m. Sun. 7.45.10.15 am.; socket set Chrome K(' and 3650 KC. :Must S. new. llinsdale SI. STASIPS. HUNDREDS OF U. Daily 4.45.8.45 pm. vanadium steel midget cost $8.00. shape with holder. Write Wendell old. Schuster, \ \'est 4th Street. Mt. first issue up. l'aner. 40 years Want mike, SW -3, test equipment or 919 handmade leather articles. Rant small 6.070 HP3ABF BOGOTA, COL., 49.42 m., La Voz Cirntel, 111. superhet. E. Decobert Jr.. 609 shortwave radio. Or wlsat have you. de Bogota. Henrietta St.. Gillespie. 111. HAVE DX -4 SHORT WAVE ItE- All letters answered. Roy Harding, movie projector. 6.070 CFRX TORONTO, CAN., 49.42 m. Relays 50 SAXOPHONE LESSONS BY ceiver. Keystone Burlington. Kane. original cost $10. Westinghouse 1/50 Virtuoso Music School. type 53 Syl- T It A D E FOR OSCILLOSCOPE. CFP.B 7.30 am.-I2 m., Sun, h.p. motor. signal high frequency 10 enia radio tube and a 164 page Unite No. 1 and 3 completely wired 3m.-I2 m, book with (bins". Will trade buzzer and 1 tube portable e iver. tubes. ready "Tricks 12216 Taft ttAve., with crystal. meters and 6.070 VE9CS VANCOUVER, B. C., CAN., 49.42 for what have Bill Schroeder. Want? Earl Carter. transmitter. you? Cleveland. Ohio. to operate. Utah 80 watts 10.30 803 tWisconsin. Peoria. Ill. never used. L. B. Holtz. 553 Carroll m. Sun, 1.45 -9 pm., pm: I ern.; Tues. 6 -7.30 pm., 11.30 WILL SWAP LATE 1931 HUDSON HAVE GOOD SKY BUDDY. CO11- St.. Akron. Ohio. plete. Want ACSW3, transmitting -1.30 6 -7.30 in shape for good - pm. am. Daily pm. De -Luxe sedan Al parts, low power CHEMICALS! OVElt 100 DIFFER 2%x2% reflex camera or what transmitter. glass containers-exper- quality Witte L. C. Bohn. Bancroft 27, ent kinds -in 6.069 TANANARIVE, MADAGASCAR, have you in photo supplies. David imental quantities. Will swap for - 49.42 m., Addr. (See 9.53 mc.) Exeter. N. H. Snyder. 347 Georgia Ave., Brooklyn, a of and S.W. receiver, pair phones 10.11 am., New York. WANTED RACK ISSUES OF ALL loudspeaker. or what have you! Harold 12.30. 12.45, 3.30 -4.30, magazines from 1936 to date. Y. Sun 2.30 -4.30 am. SPORTSET 1 radio Storch. 91 E. 208 St.. N.Y.C.. N. TRADE POCKET Have or can get anything you want. tube battery kit, made sip of new SIIMEO- 6.065 SBO MOTALA, SWEDEN, 49.46 m. Re- Hammarlund value $4.34 and Jack E. Bannon. W'BJXV, 412 Seneca VIOLET RAY MACHINE, parts, St.. OR City, l'enfla. graph. lays Stockholm 1.30 -5 pm. pair Cannonball master headphones stampa. or what STAMPS for cousefullaitems. U.S. 3.000 ohms, for radio books I WII.L EXCHANGE electric old auto radiator name 6.060 - TANANARIVE, MADAGASCAR. have you? Alexander Podstepny, 217 of Australia and New Zealand for drill. Plates. 1limeographed list for stamp. 49.5 m., 12.30- 12.45, 3.30 -4.30, IO- rifle St.. Phila.. Penna. stamps of other countries. preferably 2509 East 89th. Cleve- Colonies. Gibbons catalogue Rudolph Zak. Il am, WOULD LIKE TO TRADE British land. Ohio. stamps with any one. Have stamps Fbasis of exchange if preferred 6.060 WBXAL CINCINNATI OHIO, 49.5 m., Rica and Nicara- A. Clayton. Tinana. Mar'horou¢h, BUNDLE UP YOUR OLD OR Addr- Crosley Radio Corp. Re- from Panama, Costa oust relia. gua (almost all recent issues). Want Queensland. new postcard views and send to me. lays WLW Tues., Fri., Sun. 5.45 stamps from anywhere. Antonio En- WANTED: 165151 MOVIE C.\\1ERA For each one I'll forward one piece am.12 n., II pm. -2 am.; Wed. Zone. wide angle lens. old Mexican money. (Not spendable rhuma, Box 900. Balboa, l'anal Insides. also 15113f 5.45 am. -12 n., 9 pm.-2 am.; "A" mounting. Quote price. or will now). No two r rde alike please. WILL SWAP e, TUBE PHILCO or ;6]f films. Harold Manias. Colorado, Texas. Mon., Thurs., Sat. 5.45 am, -2 am. S.H. transitone auto radio. A -1 shape. swap radio for en- Theodore Fisher. 6.060 W3XAU PHILADELPHIA PA., 49.5 m. Re- with separate speaker, photo Brewster. Box 531. Raton Rouge. La. WILL PRINT 1.000 SW 1. OR HAM larger, or what have you in photo cards to your individual design. In lays WCAU tues., Fri., Sun. 12 apparatus? Jack Feibush. 79 Mont- TRADE 1 -12 GAUGE. REMING soap for 2 or 3 tube complete SW n.-II pm.; Wed. 12 n:9 pm. gomery St., New York Cid. ton pump gun male) 10. 2 -11 Etim' receiver in working order. Mite Owl SWAP SKIING EQUIPMENT. inators. 1- Direct current generator 2 Print Shack. 718 Allendale Street, 6.057 ZHJ PENANG, FED. MALAY STATES, 2 Want: all wave for rect'r., parta. or? I swap SWL's. KW.. 125V., amp. Baltimore, Maryland. 49.51 m. 6.40 -8.40 am., except Justin Mueller. signal generator. oscillator, service Sur., also Sat. Il pm, -1 em. 100% USE. Write! aimer receiver. John TO HAVE LISTS 1883 So. Itivd., Apt. IC. Bronx, N. Y.. tuipment. SW WOULD LIKE Frenzel. 47 Bradford St.. Auburn. of receiving and transmitting article, .6.054 HJ6ABA PEREIRA, COL 49.52 m. 9.30 am: New York. which are for sale or exchange. Send 12 n 6.30 -10 pm. HAVE: HOME STUDY COURSE WANTED TO BUY. A l'SE» your SW'L card for my new red and in electrical eng.. Ridera manual. silver one. Dean Cooper. 17 South 17th, 6.050 GSA DAVENTRY, ENGLAND, 49.59 m., Rant commercial receiver. such as Belli- *Ise technical electrical books. crafter SkSrider. Challenger, Na- Fort Dodge, Iowa. 12.20 -4, 4.15 -6 pm. good A.C. communications receiver. All Sargent. etc. John answered. C. Tyls. 502 East tional receiver. i WOULD LIKE TO SWAT' A 6.050 HP5F COLON, PAN., 49.59 m., Addr. inquiries 410 Valley Street. McDonald. N. Y. C. Kotos, National SW3 complete with 80 and Ca-Iton Hotel. Irregular. 84 St.. Pa. 40 meter bandspread colts. also power MEXICO, 49.6 m- HAVE GOOD l'NMOCNTED - Miss 6.045 XETW TAMPICO, Ir- meter frequency 3042.5 HAVE ONE 7 TUllE SUPER SKY supply. for No. 9 hiders Manual. eight' crystal. 5 one 2 tube 21 555 St.. regular 7 -1I pm. crystal having a fre- rider, Model and Rosemary Schmuck. Carroll -Will swap for 7 what have 000 or 190- watt xndtter. and parts, for Akron. Ohio. 6.042 HJIABG BARRANQUILLA, COL., 49.65 m., quency between -7075. 6925 or Henry 1960 -1990 kilocycles. All In- you. Call Mt. Emisora II 7200, or \\'roblenski. 2601 N. Iloyne Ave.. I \\'ANT TO TRADE BOY MF:- Addr. Atlantico. em: guides answered. \c4EF'K. 1503 West Chicago. 111. chanic No. 4. 16mm movie film and 11 pm.; Sun. II am.-8 pm. Cass Street. Tampa, Fla. of dance bands for FOLDING late recordings W4XB BEACH, FLA., 49.65 m. WANTED: "IAFAYETTE l'llO- HAVE EASTMAN 3A whatever you have to truste. Melvin 6.040 MIAMI Kodak. and case. mareelle irons 9 fessional Nine" or similar super - guitar McCandless. 408 North Nain St., 1.3 pm pm.-I2 m. Relays which rovers from and electric heater. Niagara School of Kirksville. Missouri. W IOD. heterodyne receiver piano course. National Geo- 10 to 160 meters. A.V.C. and R.F.O. Music required. graphies. Want short wave radio. WILL SWAP A PERFECT ('ON- 6.040 WIXAL BOSTON, MASS., 49.65 m., Addr. preferred but not absolutely service equipment. or what? Describe results and price. Gordon manuals. dition Winchester 44 -40 caliper rifle University Club. Irregular. C. Pollack. Chanute. Kans. with and case. value Nordstrom. Hyland Station Rte. 7. peep sight gun CITY, PAN., 49.75 m. $35. for a gnat communication receiver. 6.033 HP5B PANAMA Minneapolis. N' Inn. WANTED- PHONO. EQUIPMENT 910. 9.30 I for P.A. work. State price. condition, Harry W. Bell. 961 Van Dozer St.. Addr. P. O. Box am: WANTED 5 METER TItANS- St., Stapleton. S.I.. N. Y. prr., 5.10 pm. with power etc. Ervin 11111, 1987 16th Akron, cetcer must be complete Ohio. supply. Send full Info. M. (Mart's HAVE 2 YEARS' COPIES OF 6.030 VE9CA CALGARY, ALTA, CAN., 49.75 m. Greene. 68 East 3rd Street. New TRADE-NEW WESTINGHOUSE. Ring Magazine. boxing anti fiction Thur. 9 am: 1 am.; Sun. 12 n: York City. 200 watt A.C. generator. Want crystal books (history of all boxing cham- 12 m. AP- mike or 61A i tat ostinato, Il. O. pions). Will tracte for model A Argus HAVE CHEMICALS AND Rd., KC.. Mo. OLR2B CZECHOSLOVAKIA, paratus for correspondence course in Reid. 7313 Betinder candid camera. Write for detalls on 6.030 PRAGUE, Mineralogy from 4'.C., Chemical WANTED: RIDERS MANUALS. boxing books. Don E. Kailbourne, 49.75 m- (See 11.875 mc.) Off the Microscopy Handbooks by Chamot and No. 1. 2. 3. 4. 5. 6. 7, 8. 9. Will Genesee. Pa. air at present. Mason. Want Multimeter transformers. buy or swap speaker. sets. tubes. 6.023 XEUW VERA CRUZ, MIX., 49.82 m., Addr. Netada anything electrical. Martin J. TRADE: ELEVEN TUBE 1937 pads. Herold Conti... moon two Av. Independencia 98. 8 pm... City. Calif. Kelly. 69 Valley St.. Providence. R. F. table model !Cadette radio. It has bands and tone control. Want a Sky 12.30 am, HAVE 5 TUBE A.C'. SHORT WAVE WANT SERVICING INSTRU- Champion or other band switching set, Magnovox dynamic speakers. ments, have 1934 fire tube battery receiver. Must have 10 meters. Hue 6.020 DJC BERLIN, GERMANY, 49.83 m., Baldwin head phones, Western Elec- radio less cabinet. one tube radio and Diament. Perkiomen School. l'enns. Acdr. (See 6.079 mc.) 10.40 am: tubes. trie cradle phone. Weston meters. colle, telephone pike. used burg. Ps. 4.30 pm, Webster phonograph pickup, swap stamp collection, many other things in Ilst. Want camera or binoculars. M. Arden Rowe. 521 TRADE JENKINS TELEVISION 6.017 HI3U SANTIAGO DE LOS CABALLEROS City. 10mm Craie Simon, Box 441, Gary. Indiana. Steewwartcondition.Grove receiver, lese Televisor. D. R., 49.85 m. 7.30 -9 am., 12 n. and rewind. Kotasrope 16mm SPEAK - EXCHANGE: KEYSTONE MOTOR Dllcer TRADE 18- ADJ. MAO. Viewer. All letters answered. David 2 pm., 5.7 pm., 8 -9.30 pm.; Sun. banjo 500 pre - driven 165151 movie picture projector er, field glasses. uke, Gross. 2145 Ocean Ave.. Itrooktyn, 12.30 -2, 5 -6 pm, cancels. 300 postmarks. stamps, Baby and 100 ft. of film. cost when new Brownie camera, photographie quip - $18. for a good mike and record PRAB PERNAMBUCO, BRAZIL, 49.84 m., Bloom- 6,015 ment- two books- Auto Safety lighter. pickup. Gordon Smith. 8001 WANTED. USED SENIOR IN- Radio Club of Pernambuco, 6 -9 ACH sharp tuner dial, radio parts. field Ave.. Montreal. Otte. slructograph In good condition with pm. R. Lewis. Grilfthellle. Ark. EXCHANGE - DRIVER JIGSAW all or most tapes. and instruction WANTED NEW TUBES. RIDER machine 3505, Including accessories. book. preferahly. Do not want oscil- 6.012 ZHP SINGAPORE, MALAYA. 49.89 m. fifer. manuals. test equipment. new radio 14 horsepower D.C. moor, used 4 or lator equipment. Cash for u best 5.40 -9.40 am -, irregular. parts. Have P. transformers trans- 5 times. for goal camera or short All replies answered. Bob Palmer. mission line. speakers. used tubes. ware set. J. Wiener. 884 Southern 4832 Caroline. liouston. Texas. 6.010 OLR2A PRAGUE, CZECHOSLOVAKIA. power ennuis. Majestic model 90 Boulevard. Bronx. N. Y. 49.92 m., Addr- (See OLR, 11,84 What Joseph HAVE WEIGHT & DITSON CON - A.B.C. have you? NF.W' $4.41 UNIVERSAL SINGLE Cost $6.95. mc.) Off the air at present. Gevlado. 159 Sabin St.. Pawtucket. LD2 or tender Tennis racquet. button mike for Bliley Used twice. Good condition. Trade for HAVANA, CUBA, 49.92 m., Addr. Rhode Island. Bliley B5 crystal between 7.000 ke /s 6.010 COCO 3 tube A.C. SW set of Ilke value. P. O. Box 98. Daily 7.55 am: SV.'AP 16MM MOVIE PI(TUBE and 7,175 kc /s. Exchange data fient. Must be ready to use. Teddy W'ltowski. and James C. Moulton. 4912 Quebec 12 m., Sun, until II pm. projector for 40 meter crystal Witte: 7 Stebbins St.. Ludlow. Mass. holder. Also swap SWL cards. Homer Street. N.W.. Washington. D. C'. 49.92 m. (Travels PICTURE. 6.010 VK9MI S. S. KANIMBLA, Evans, Jr., 205 West Main St., Port- HAVE CAMERON'S "SIOTION WANTED: MOTION Australia and New Zee - land, Ind. Cameras. films. etc., electric between Picture Projection." recognized author - projectors. lend). Sun., Wed., Thun. 6.55- latest cost $5.00. Trade trains and equipment. nmalel airplane WILL SWAP POSTAI. CARDS 1t', edttion. Have and correspondence with distant radio for Ghlrardl's latest "Modern Radio motor. minuter dance records. 7.30 am. welcome. Radio Servicing." or what have you sere - amplifiera, low powered transmitters. en. fans. YL fans are on Newsome, Box 6.010 CJCX SYDNEY, NOVA SCOTIA, 49.92 Glenn G. Godwin, 5 Icing? E. W. Witte, Marion, S. recetvere. etc. Johnny W801LX, Mil- Relays CJCB 7 am: I pm., 4.8 pm. dred Ave.. Binghamton. N. Y. Dakota. 725, Wake Forest, North Carolina.

RADIO & TELEVISION 508 Please soy you saw it in RADIO & TELEVISION

www.americanradiohistory.com Mc. Call 6.007 ZRH ROBERTS HEIGHTS S. AFRICA, BARTER and EXCHANGE FREE ADS (continued) 49.94 m., Addr. (fee ZRK, 9.606 mc.) Daily exc. Sun. 10 am. -3.30 TRADE FOR pm.; Sun. 9 am.-I2 n., 12.15- TYPEWRITER AR- YOtIt SWL CARD WILL BE AP- SHORT WAVE LISTENERS IN tides of value such as tools. card Dreeiand. Answer all. Lewis Neuman, 3.15 pm. Daily exc. Sat. 11.45 U.S.A. and foreign countries. Would 111e, offre supplies, pen and pencil set, Box R363, Pittsburgh, 1181 Penna. like to exchange my SWI. card for pm. -12.50 am. kodak, etc. Prank Hendshue. Saville, yours. SWL'S WILL SEND MY Louie Kucere. P.O. Box 101, 6.007 ZRJ Ohio. C:Utl; Apache. Oklahoma. JOHANNESBURG S. AFRICA. for one of yours. I QSL 100%. L.S.A. 49.94 m., Addr. S. African Broad- SWL EXCHANGE or foreign countries. F. E. Vlasscy, AUSTRALIAN SWL WOULD LIKE cast. Co., 3.30 -4 pm. exc. Sun. 58. St. Annes Road. Cornnteadow, to exchange cards with U.S.A. and SHORT WAVE LISTENERS IN \Vnrrester, England. foreign listeners. Ilia Percent QSIs 6.005 HPSK COLON, PAN., 49.96 m., Addr. all countries. Would like to exchange from here: How about WOULD LIKE: TO it. chaps? Box 33, La Voz dc la Victor. 7 -9 SWL cards with anyone anywhere. :MAP SWI. (lE(A- Albert E. Kent. "Cranbury." cards with SWL's anti Hants all met am., 10.30 am. -I pm., 5 -11 pm. URA-Art. Cormtnboeuf. 113 Parrot Stoney Creak Road, Ilurstvtlle. N.S.W., Place, Brooklyn. N. Y.. C.S.A. the world. but mainly In foreign coun- Australia. 6.005 CFCX MONTREAL CAN., 49.96 m., Can. tries. What say old Bug? F. A. Moore, SHORT W A V E LISTENERS. I09 W. Granville SWL'S AND IIA)IS A1.1, (W ER Marconi Co. Relays 6.45 Rd., Worthington. CFCF SWL's I would like to swap crd'a Ohio, C.S.A. the world. Let's cop rds. I QSL S. a am.-I2 m.; Sun. 8 am. -10.15 pm. with U. and foreign countries. 100%. URA-Joe s lterly, I WANT TO SWAP QSL CARDS Jr.. IOi N. 6.005 VE9DN (181, 100% hr. QRA--Arthur Woods, Clemson Ave.. Clruis,m. S. Carolina. DRUMMONDVILLE, QUE., CAN., It.F.D. No. 1. Wellsburg. W. Va., with YL amateur radio ops, Will (l 1. 49.96 m., Addr. Canadian Mar U.S..'.. 1007. W9SEF, Harold Lantay. Ren- SHORT WAVE LISTENERS IN coni Co. wick. Iowa. all countries. I would like to swap WOULD LIKE TO EXCHANGE SWL cards with anyone anywhere. 6.004 RV59 MOSCOW, U.S.S.R., 49.97 m. Ir- SWL cards with any SWL In U.S. ATTENTION! SWL'S OR PIC- URA -Jack DeMay, 615 -00 St.. regular. ur foreign countries. All cards received tore postcard collectors. Will swap my Brooklyn, N. Y., U.S.A. here will be a s wren' wills our card. SWL. card or picture postcard r both 6.002 CXA2 MONTEVIDEO, URUGUAY, 49.98 m. QI.\ John 1.. Bailin. 40 East cc St., for one or both of yours. I will reply SIIOItT WAVE: LISTENERS AND Addr. Rio Negro 1631. Relays New York. N. Y. Promptly. George Mills. 13. (rilchley hamsts in U.S.A. and foreign countries. street. Ilkeston, Derbyshire. England. LS2, Radio Prieto, Buenos Aires. I USI. 10417, SWL's in all Like to send one of ley SWI, cards pans in exchange for Fred W. G.xtds, IO am.-I0 pm. of the world. I will exclange my card 1 1VILL EXCHANGE SRI, CARDS yours. for yours. CIRA-Jock with any person American or 2437 Shattuck Ave.. Berkeley, Calif., 6.000 Clements. 6800 foreign. ZEA SALISBURY, RHODESIA, S. AFRICA, Division Ave.. Birmingham, Ala., What say gang Ht Fred White. 34 50 m. (See 6.147 mc., Gould Street. Wakefield. Mass., ZEB.) Also C.S.A. ATTENTION SWL'S ALL OVER Sun. 3.30 -5 am. SHORT WAVE LISTENERS IN POSTCARD %11-.MS. S\\'1. CARDS the world. 1 will swap cards 100% U.S.A. with 6.000 XEBT MEXICO CITY, MEX., 50 m., and foreign countries. \You'd wanted at this SRI, post from all everyone. Let's be the best of like to exchange my SWL t for countries. Will correspond with friends. (I IL\ -H. It. Emmett. 1639 Addr. P. O. Box 79.44. 8 am. -I SWL's - yours. Also swap 'shark" photos. I Africa. Asia. All letters, cards an. Sixth Street. Portsnmuth. Ohio. am. QSL 1011%. Edmond Brununer. 34 -21. swered 100%. (.111A- VE3SR'1.. Mere- SRA1' SWL OR POSTCARDS 89115 Street, Jackson Ileights, Lang dith M. Stroh. 172 Queen St., Island, N., with everyone, everywhere. Maylan End of Broadcast Band New York, U.S Kitchener. Ontario. Canada. Wilbur. Held. Maine.

5.977 CS2WD LISBON, PORTUGAL, 50.15 m., Addr. Rua Capelo 5. 3.30.6 pm. 5.975 OAX4P HUANCAYO, PERU, 50.16 m. La Let s Listen In with Joe Miller Voz del Centro del Peru. 8 pm. on. (Continued from page 489) 5.970 YV5RC CARACAS, VEN., 50.26 m., Addr. JAPAN -Mr. Gallagher reports this news from Radio Caracas. Sun. 7 am. -10 pm. West Coast. ASIA Daily 7 -8 am., 1 -1.45 pm., 4 -9.30 JZZ, 17.78 mc., with a special broadcast 8 -8:30 VU2CQ, 14270 kilocycles, India, reported by or 10 pm. a.m., requesting reports. Roy Myers. JVH, 14.60 mc., broadcasting KAIJM, 14300, the yacht "Jen." 5.968 HVJ VATICAN CITY, 50.27 m. Off the program Suns. - in Manila 12:30-1 a.m., often till 1:15 a.m. Harbor. P.O. Box 817. Manila. Philippines, is a air at present. new one JVL, 11.66 mc., phoning 1 a.m., also JVA, heard by Ashley \\'alcott, Also KA3KK, 5.950 HH2S PORT -AU- PRINCE, HAITI, 50.37 18.91 mc. 14320, Boguio. which is operated by the w.k. KA's, m., Addr. P. O. Box A103. 7 -9.45 1YL, and 1ZL. Roy Myers also reports KA3KK. Dm. INDIA -On \ \'est Coast. Delhi on 4.99 mc. Call VS3AF, 14350. in Jahore, Non -Fed. Malay 5.935 YVIRL MARACAIBO, VEN. VUD2, is heard stronger than on 9.59 mc.. 50.52 m., this States, is a nice DX catch for Mr, Walcott. Con - Addr. Radio Popular, Jose A. on the morning schedule. Roy Myers and Ashley grats, OB. Higuera M, P. O. Box 247. Daily Walcott report the 4.99 mc. freq. Morning sched- \'S6AG, Hong Kong- is a 'regular" ule is 6:30 on 14080. 11.43 am.I.43 pm., 5.13 -10.13 a.m. on. FISAC, French Indo- China, our of friend Rene, pm.; Sun. 9.13 am. -3.13 pm. is often heard on 14070. TURKEY-TAO. 15.195 mc., at Ankara, is 5.913 YV4RP VALENCIA, VEN., 50.71 m. Irreg. reported From Burma, XZ 2DY, 14100. has the best "Sig," heard. with a schedule of I:20 -5 p.m. This station sez Ashley, who reports other 5.900 ZNB MAFEKING, BR!. BECHUANA- believed ox above. Others, is to relay 2R04 quite often. as the much weaker, are XZ2EX, 14340, and XZ2PB, LAND S. AFRICA, 50.84 m. Addr, Italian station's programs are often heard through 14040. The Govt. Engineer, P. O. Box TAO. This new and as yet unconfirmed station is PKIGL, 14270, PK1\'V, 14270, and PK2RN, 106. 6 -7 am. 1 -2.30 pm. also reported on 9.465 mc.. daily from 6:30 -7 a.m., 14320. are reported 7.8 a.m. by Gail Beyer, \\'9. 5.900 TILS SAN JOSE, COSTA RICA, 50.85 m. but we believe this to be on only irregularly. FB. OM! 6 -10 pm. Ralph Gozen retorts a veri of PK1VY. 5.898 YV3RA EGYPT 13.82 nie.. BARQUISIMETO, VEN., 50.86 m., -SUZ, Cairo, heard at 12:45 We recently received a veri, somewhat late. p.m.. using inverted speech. SUZ is very Addr. La Voz de Lara, 12 n: I often front PK6\VF, who is OM Federoff. conducting a om., 6 -10 pm. heard at 11 a.nn. in schedule with GBI3, 13.585 nie., geological expedition into the wilds Rugby. of Dutch New 5.885 H198 SANTIAGO, Guinea and Papua. Believe it or not. OM Federoff D. R., 50.95 m. Irreg- sent us the ular 6 -11 pm. QSL, together with a dozen "FB" MOROCCO -CNR, 12.83 mc., at Rabat, was logged photos of native scenes, very once at interesting, too, all 5.875 HRN TEGUCIGALPA, HONDURAS, 51.06 2:45 a.m.. with a woman heard phoning by air retail from Dobo, New Guinea!! Talk about m. 1.15 -2.16, 8.30 -10 pm.; Sun. in side band secrecy. CNR usually heard in early being obliging, whew! Wish afternoons. we could enlarge on 3.30 -5.30, 8.30 -9.30 pm. this interesting letter here. Tang a million, OM! 14180- 5.855 HIIJ SAN PEDRO DE MACORIS, D. J6DU, J5CC, 14405, J2\11, 14080. and R., DUTCH BORNEO-YCP. 9.12 mc., at Balikpapan, J2CR. 14035, reported 51.25 m., Addr. Box 12 all by Jim Doyle. \V9. Vy 204. n: heard almost daily, contacting a new Javanese FB. 2 pm., 6.30.9 pm. OB! Ralph Gozen also reports J5CC. phone on 10.055 me.. at 4:30 a.m., by N. G. From South Africa, the following are reported 5.845 YVIRB MARACAIBO, VEN., 51.3 m., Stahevitch. W6, Both were heard R8 -9. Clear on 20 meters: Addr. Apartado speech transmission used only. Here's your 214. 8.45 -9.45 chance ZSIAX, 14080; am., 11.15 am. -12.15 pm., 4.45- to "log" a rare new country in Dutch Borneo! ZS1BL, 14360; ZSICN, 14070 and 14290; ZSIB, 14060; 9.45 pm.; Sun. 11.45 am. -12.45 All Javanese phones are QSI.d through the Java- ZS2AZ, 14120; ZS2AH, pm. nese phone QRA (address) in Bandoeng. 14020; ZS2It13, 14050; ZS2N, 14030; ZS4H, 14270; ZSSAW, 14090; ZS5AD, 14100; ZSSBZ, 5.825 TIGPH SAN JOSE COSTA RICA, m., 51.5 MOZAMBIQUE- 11.718 14030; ZSSBH, 14400; ZSSBS, 14140, 6 watts; Addr. Alma Tice, Apartado 800. CR711I1. nie.. heard weak- ly of late. during afternoon schedule. 3.4 ZSST. 14050; ZS6AJ, 141.30; ZS613A. 14350; 11 am.-1 pm., 6 -10 pm. Relays p.m.. by Jack Iluitekant, \Y2. Mr. Sr.,hrvitch ZS6I)J. 14040; ZS6AD, 14080; ZS6DM. 14090 TIX 9 -10 pm. reports and CR7IIH at 10 -11 a.m. on VVe,t t- R7. 14300; ZS6DW. 14040 and 14070: ZS6W, 5.813 TIGPH2 SAN JOSE, COSTA RICA, 51.59 14030 and 14370; ZS6EF, 14370; ZS6EY. 14080; m., Addr. Senor Gonzalo Pinto, ZS6ED, 14040; ZS6FI3, 14140. H. ZEIJX in Southern Rhodesia on 14020. 5.790 TGS GUATEMALA CITY, GUAT., All above reported by Roy Myers. Ashley \Val. 51.75 cott and N. G. Stahevitch, m. Casa Preidenclal, Senor J. M. all W6. Ca ba lleroz. Irregular. M&STARDOST. ., \'Q2HC, 14310. heard by Roy Myers. from 5.758 YNOP MANAGUA, Northern Rhodesia. Mr. Stahevitch also reports NICARAGUA, 52.11 this catch. m. 8 -9.30 pm, The amateur bands have shown renewed activity with the advent ZL_JQQ 14050, reported by Gail Beyer. 5.740 YV2RA SAN CRISTOBAL, VENEZUELA, of cooler weather. and from now on. there'll be plenty pie ZL2BE. New Zealand. on 14210. heard at 7:10 52.23 m., n for all. Addr. La Voz de Ten meters has opened up nicely. and numerous a.m. by Roger Legge, W2. Tachira. 11.30 am. -12 n., 5.30 -9 South A nice one on 20 is CNIAF. 14280. heard pm., African phones are being logged at up to Sun. till 10 pm. R9. This "FR' reception should continue right pearly daily 5 -7 p.m. Many report him. Located through to February. though. of course, 10 is It Tangier, International Zone. QRL is Jose M. 5.735 HCIPM QUITO, ECUADOR, 52.28 more m. Ir- subject to variations in conditions than 20 m.. the Sierra, 19 Rue Sources. Tangiers, International regular 10 pm. 12 m. of reliable Yx band. Best tines for 10 on East Zone. CNIAF QS1.'s promptly, 5.145 OKIMPT PRAGUE, CZECHOSLOVAKIA, Coast is frnm 11 a.m. -1:30 p.m., when Europeans. ZBIL. 14130, Malta, reported by Gail Bever. 58.31 m., Addr. (See OLR, 11.84 and later South Africans. are well heard. On 10 meters. w'a've mc.) heard a few So. Africans Fri. 4.45 -5.10 pm.: Sat. 5.15- Also reported are occasional ZL's and VK's. in the brief time we've tried this hand on Suns. 5 40 pm. these heard in early evenings front 6 -8 p.m.. but ZEIJR, ZEIJN, ZSIAX, ZS5CL, ZS6S. ZS6A, 5.145 PMY BANDOENG, JAVA, 58.31 m. 5.30- very irregular, here on East Coast. ZS6E(`,, ZS6DY, ZS4H are all we've heard. 1I am. Twenty meters is rather quiet now. but South Roger Legge reports ZL3BV at 7 p.m.. also should 4.995 VUD2 DELHI, INDIA, 60.06 m., Addr. Africans begin to evidence themselves soon ZT.2BT. Also ST'1RO, at 9:30 a.m., all on 10. All after this appears. on 'odia Radio. 7.30 am.-I2.30 pm. article East Coast. front F13. Roger! 11 p.m. -1 a.m. 4.950 VUM2 MADRAS, INDIA. 60.61 m. Addr. A tip: VR6AY doesn't want reply coupons, as Very few Asiatics are now heard in East they be All India Radio. 7 am.-I2 n, in cannot redeemed. Send I'. S. stamps or mornings on 20. the West Coasters enjoying more 4.905 VUB2 New Zealand stamps. BOMBAY, INDIA, 61.16 m. Addr. or less exclusive reception of the PK's, VS's, etc. Let's hear from all you OM's next All India Radio, month. All 7 am.-12.30 pm. Here goes: our \'y 73s to you, OB's, es lots es lots o' DX to ye! for December, 1938 Please say you saw it in RADIO & TELEVISION 509

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This HOW TO BUILD A 200 WATT )(MUTTER WITH HOW TO BUILD THE SWITCH BAND -2 RECEIVER. HOW TO MAKE A REAL 5 -METER SUPERHET. ultra short vvio e recep- PEN -TET EXCITER. This transmitter will really go to A low -cost receivereiver for 6 volt battery or A.C. operation carefully designed receiver for hear stations in all tion employs a straightforward circuit. Careful place- town. The use of the Pen -Tel crystal oscillator and which enables the short -wave fan to many head- the world No. I ment and high quality parts insure fine results No. 17 frequency multiplier circuit eliminates parts of aches from cracked crystals No. 32 HOW TO THE 2 -VOLT SUPER DX -4. This 2 RECEIVER FOR THE BUILD HOW TO MAKE A -TUBE superhet. though small in size is big in performance. HOW TO BUILD A 10 AND 20 METER TRANS- BEGINNER. This receiver consists of detector and two which worked to secure Using battery type tubes. it features continuous band - MITTER. A 200 watt transmitter orld audio sieges. A double purpose tube is used wide on test. Although compact. it is highly volt battery Aer- spread, and automatic volume control. which may be cut DX the 2 audio stages. Tube. are for 1% 18 efficient in the 10 and 20 meter bands. Five tubes are No. 2 in or out as desired No. ation. used. No. 33 4. HOW TO MAKE THE ULTRA -HIGH FREQUENCY MAKE THE PORTABLE SUPERHET I -TUBE 50 -WATT HOW TO WIZARD -6. This Is a first -class 5 -meter super- regenera- HOW TO MAKE THE WIZARD An ace all -wave superhet for battery operation. This TRANSMITTER. An amateur. crystal -controlled c.w. beat tive receiver, using acorn tubes in the H.F. and detector receiver features band -spread and has a built -in use transmitter using the 111(20 screen grid pentode. In tests. No. 3 stages. The other tubes are of the metal type. The oscillator. of the acorn tubes insures exceptionally fine results. No. 19 it compares with 250 -wafters No. 34 SUPERHET. HOW TO MAKE I TUBE HOW TO BUILD A 4 -BAND 3 -TUBE HOW TO BUILD A HIGH -GAIN METALTUBE RE- THE "OSCILLODYNE" A 3 -tube receiver giving 4-tube results. Back and panel WONDER SET. One of the moet sensitive short -wave CEIVER. This little receiver is a real performer, tuning the type construction is employed. It has a regenerative band -spread is sets designed. employing a really new circuit for No. 4 from 10 -200 meters. Continuous pro- rperated NO. 35 second detector vided. No. 20 first time. Battery HOW TO MAKE THE "19" TWINPLEX (ONE TUBE HOW TO MAKE A FIXED -BAND 8 -TUBE SUPERHET. TO -WIDE 10 -METER a band HOW BUILD THE WORLD PERFORMS AS TWO) RECEIVER. One of the most This short -wave "fan" receiver tunes over wide reports have been re CONVERTER. Many enthusiastic sensitivee 1 sets ever and very of frequencies without coil switching or changing. It's be -tube designed popular. A.C. mired from the builders of this unit. which may No. 35 a real performer. It operates directly from 110 V. receiver for up 30 meter No. 5 attached to your present picking and has band - spread signals from all parts of the world. Only 2tubes are HOW TO MAKE THE IMPROVED 3 -TUBE DOERLE SET FOR BATTERY OPERATION. One of the finest of 140W TO BUILD A 5 -TUBE SUPERHET FOR FAN used. No. 21 -wave en- the Doerle series. by the famous short -wave inventor. AND HAM. A sure -fire receiver for all short A DE LUXE 3- TUBER. This is the No. 37 and core I.F. HOW TO BUILD thusiasts. It uses plug -in coils iron receiver for the Ham or Fan who wants a really high of No. 6 HOW TO MAKE THE "GOGET-'EM 2" RECEIVER transformers which assure plenty gain class receiver Of simple design. It employs an unusual FOR THE BEGINNER. This unusual 2 -tube circuit HOW TO MAKE A TWINPENTODE RECEIVER. band -spreading dial. The circuit. employing metal for the beginner. em- of followed by a regenerative gives 3 -tube results. Battery operated. Excellent This receiver. especially designed for tubes, has a stage T.R.F. beginners. No. 35 ploys but one dual purpose tube which gives results detector and a stage of audio No. 22 2 receiver. is for 2 -volt battery HOW TO MAKE THE ITUBE ALL -ELECTRIC OSCIL. equivalent to a -tube It HOW TO BUILD THE OCTODE METAL TUBE -3. Operation with headphones No. 7 LO DYN E. This is the famous electrified short -wave re- This receiver is capable of excellent performance on on A.C. AN SHORT WAVE -in coil for ceiver. Easy to build for little money. Operates HOW TO BUILD EFFECTIVE the short waves. It requires only one plug and D.0 No. 39 PRESELECTOR. A signal- booster that will greatly im- each band as a stage of untuued R.F. precedes the prove reception on any short -wave super. It employs two detector. It also has an A.F. tage for boosting the HOW TO MAKE THE 2 TO 5 METER TWO -TUBE used 6K7 tubes In parallel in highly efficient circuit in volume to comfortable headphone s level No. 23 LOUDSPEAKER SET. This receiver may be with which both input and output are tuned No. 8 batteries or with an A.C. power pack. Packs a big 3 -1 REFLEX SET. A 2 -tuber This HOW TO MAKE THE -IN wallop. No. 40 HOW TO BUILD A REGENERATIVE 2- TUBER. giving 4 -tube performance Is this receiver which does screen HOW TO MAKE THE 3 -TUBE BATTERY SHORT- unusual receiver has the tickler coil in the grid its work with a minimum of tubes. A 6F7 is used as a circuit of the detector. The receiver tunes from 9 -270 combined R.F. amplifier. detector and first audio stage: WAVE RECEIVER. This receiver was a prize winner in or glass tubes WAVE CRAFT. An unusual short -wave receiver. meters: band -spread is included: metal a 6C5 is used as second audio stage No. 24 SHORT may be employed No. 9 easy to build No. 41 HOW TO BUILD THE 100 WATT ORM DODGER HOW TO MAKE THE S.W.&T. COMMUNICATIONS This M.O.P.A.- THE BRIEF -CASE SHORTWAVE RECEIVER AND receiver for the critical A COMPACT 5.5lETi R TRANSSII'1TER. HOW TO BUILD IT. So small that the entire set. bat- RECEIVER. An unusually fine a by use of a calibrated rig puts out hefty signal and teries. head set, aerial and everything. goes Into a brief- Ham and Fan, incorporating many exceptional features. overcome the QRM in the first detector stage vernier oscillator control will problem case. Stations from Europe are often received. By Hugo Regeneration is employed on 5 meters No. 25 which makes use of an acorn tube. The receiver also Gernsback and Clifford E. Denton NO. 42 incorporates a noise -control circuit. variable selectivity HOW TO BUILD A DE LUXE 5-METER MOBILE HOW TO BUILD THE POCKET SHORT -WAVE RE- control and a tuning meter No. 10 STATION. A really fine SI.O.P.A. mobile transmitter CEIVER. One of the smallest, pocket -size. battery re- HOW TO MAKE A BAND -SWITCHING 2 -VOLT RE- which will work real DX on portable location. It em- isers ever designed by Hugo Gernsback and Clifford CEIVER. This fine receiver for battery operation employs five metal tubes No. 26 E. Denton. A marvelous set that brings in European ploys band -switching arrangement. enabling the build- HOW TO BUILD THE H -G -M MEDIUM POWER stations. No. 43 er to tune from 16 -550 meters by flipping a switch. No. 11 TRANSMITTER. A crystal control set with an output HOW TO BUILD THE CIGAR -BOX ITUBE "CATCH RECEIVER. An effective short -wave battery set HOW TO BUILT THE MULTI -BAND 2 RECEIVER. of 90 watts. Band -switching is employed for operation ALL" beginner. has a re- on the 80, 40, 20 and 10 meter Ham bands. It gave which fits into a small cigar box. insuring high portability A receiver for the short -wave It No. 44 markable tuning range of 2i4 -270 meters with band - excellent results under test No. 27 yet great efficiency coils are used and complete HOW TO BUILD THE "DUAL- WAVE" SHORT WAVE spread on all bands. Plug-in HOW TO MAKE THE 806 ALL -BAND TRANSMITTER. both data for an A.C. power supply is given No. 12 BATTERY RECEIVER. With this set. you can hear An unusual transmitter delivering 400 watts output ends of radiophone talk. on one set of phones. In HOW TO MAKE THE VS -5 METAL TUBE SUPER- from an 806 final amplifier. A crystal pen -ten oscillator other words. you can listen to a ship at sea and the B ET. This complete all -wave receiver boasts, ong is used, followed by a driver stage. Real DX has been land station communicating with it. simultaneously. by other things. variable selectivity. metal tubes. AVC m worked on 10, 20, 40 and 80 meters with this smooth means of this double receiver No. 45 band -spread. The tuning range is from 17.550 working job No. 28 RE meters. No. 13 HOW TO BUILD THE I -TUBE "53" TWINPLEX HOW TO BUILD A 125 -WATT MODULATOR USING CEIVER. The twinp)ex, although it has only one tube. HOW TO BUILD A BEGINNERS 2 -TUBE SUPER. A 35T's. This is an ideal unit for the amateur and Sill works as If it had two. Marvelous In efficiency. Uses simplified superhet using 2 volt battery tubes which is modulate any transmitter with a power input up to either batteries or A.C. power pack for 'B" supply- lust the thing for the beginner. It employs plug-in about 400 watts. A total of 10 tubes are used including No. 48 coils which cover a tuning range from 15 -200 the power supply unit No. 29 HOW TO BUILD THE PORTABLE MINIDYNE SHORT- meters. No. 14 SET. Uses no aerial. no ground. The C 150 WAVE BATTERY HOW TO BUILD THE -O -M WATT TRANS- 5:5x6 inches. Self - HOW TO MAKE A T.R.F. -3 FAN RECEIVER. This is oscillator. with total weight is 3% lbs. and measures MITTER. An unusual crystal multiplier contained batteries, tube, condensers, and loop. Highly an all- around receiver employing 2 volt tubes. A T.R.F. but one tuned circuit. It uses a pair of RK37's in sensitive c ircult No. 47 stage ahead of the regenerative detector insures good with a RIC39 driver. The crystal oscillator by parallel -BAND "PEE -WEE" 2. selectivity and sensitivity. Band -spread Is provided circuit uses a 6L6 No. 30 HOW TO BUILD THE HAM a two -speed dial No. 15 TUBER. A dandy receiver with high efficiency and band - FOR I -METER a yet the entire re- HOW TO BUILD THE FORTY -NINER -A RECEIVER A LONG -LINES TRANSMITTER spread tuning. Works loudspeaker. FOR LEAN PURSES. novel receiver features TRANSMISSION, AND A COMPANION RECEIVER. ceiver is no larger than your hand. Works with either This minded experi- an power No. 48 spare -charge detector and requires only 12 volts of B A really special job for the seriously batteries or A.C. pack distance contacts uses 2.49 tubes which be operated from menter. This outfit permits short HOW TO BUILD THE DUO- AMPLIDYNE. The ideal battery. It may cts. in en' 2 volt A battery No. 16 this hislno 1 -tube set for the beginner. One of the finest 1 -tube sets: it really gives 2 -tube performance. Slade for bat- 7 tery operation. With only ten -foot antenna brings in the good European stations No. 40 Street, New York, N. Y. HOW TO BUILD THE "MONO-COIL 2 ". No more RADIO & TELEVISION, 99 Hudson bothersome coils 5 "plug in" coils. This set eliminates Gentlemen: Fnetoced von "II find +y mittanre of i2.r,O for which 1 2 3 4 Works with Year (12 and is made to carer short -wave bands. my subscription -to RADIO AND TELEVISION for One 6 7 8 9 10 either batteries or A.C. power pack No. 50 ienterssues). Send me promptly. absolutely FREE and POSTPAID. the 15 15 Publications I have circled at the right. (CANADA AND FOREIGN 33.15.) 11 12 13 14 O NEW SUBSCRIBER D EXTEND PRESENT SUBSCRIPTION 16 17 18 19 20 21 22 23 24 25 Name 26 27 28 29 30 RADIO & TELEVISION 34 35 Address 31 32 33 36 37 38 39 40 99 HUDSON STREET to 41 42 43 44 45 Cleofie remittance by check or money order. Registerr letter If you aweá 49 SO NEW YORK, N. Y. cash or usedV. S. Postage stamps. 46 47 48 RADIO & TELEVISION 510 Please say you saw if in RADIO & TELEVISION

www.americanradiohistory.com 441 Line Television Receiver (Conlinucd Jran page 479) FREE CATALOGS and INFORMATION with reflector placed horizontal position the By carefully reading the advertising columns, you will find many offers to furnish literature one -quarter wave length behind the antenna proper. containing valuable technical information that will help you in your wo k. Use this list freely. The transmission line from the antenna Adv. to the receiver is connected to the matching Firm Business Oiler No. Coat stub (preferably by clips), so that it can Page be adjusted for maximum signal strength. Aerovox Corp. Parts Mfr. Catalog Free 503 Allied Engineering Inst. Kit Mfr. Circulars Parts List -R.F., Det. and Video Sections Free 488 Allied Radio Corp. Mail Order 1939 Catalog 491 RAYTHEON (Tubes) Free 5 -1851 tubes American Microphone Co. Parts Mfr. Catalog 29 Free 490 1-6H6G tube American Radio Institute Radio School Booklet Free 500 HAMMARLUND Astatic Microphone Lab. Parts Mfr. Catalog 11 Free 505 4 -HF-50 mmf. variable condensers H. 3 -2.5 mh. R.F. chokes Bernard, J. Test Equipment Catalog V Free 481 -prong sockets 6-8 Bliley Electric Co. Parts Mfr. Engineering Bulletin E-6 10c 494 AEROVOX (Condensers) Circular A -6 Free 13 -.01 mf. SOO V. fixed, mica Browning Laboratories Kit & Parts Mfr. Brochure. 83 1 -.001 mf. 500 V. fixed, mica Browning Free 505 4-.005 mf. 500 V. fixed, mica Bulletin ..BL-5 Tuners Free 2 -.0001 mf. 500 V. fixed. mica 1 -.1 mf. 600 V. fixed, paper CircuitDiagram5P,5G,5H Free 1 -.25 mf. 600 V. fixed, paper Brush Development Co. Parts Mfr. 2 -2. mf. 400 V. fixed, paper Catalog Free 491 4-8. mf. electrolytic Bud Radio, Inc. Parts Mfr. Catalog 139 Free 491 I.R.C. (Fixed Resistors) Station Log & Data Bk. 10c 1 -150 ohms BT (all Y. watt) Burstein -Applebee Co. Mail Order Catalog Free 497 3 -175 ohms BW 4 -1500 ohms BT Candler System Co. Code Course Book of Facts Free 500 4 -2000 ohms BT Clough -Brengle Co. 4 -5000 ohms BT Test Equipment Catalog Free 497 60.000 ohms BT 5- Cornell -Dubilier Elec. Corp. Parts Mfr. Catalog I nl 497 3- 250,000 ohms BT Free Coyne Electrical School Trade School Electrical Catalog Free 451 CLAROSTAT Radio Catalog Free 1 -1500 ohm potentiometer Dodge's Institute Radio School Catalog Free 500 MISCELLANEOUS Shielding material (copper, brass or aluminum) Dutton, E. P., & Co. Book Publisher Literature Free 503 12 -V4" stand-off insulators Eagle Radio Co. Kit Mfr. S. W. Diagrams Assorted screws Free 496 Gold Shield Products Mail Order Catalog Free 505 Hammarlund Mfg. Co. Set & Parts Mfr. 1939 Catalog Free 503 Radio Helped Make Movie "TC" Bulletin Free (Continued front page 464) Henry Radio Shop Mail Order List Free 492 tor and an 802 final with 42 speech and Instructograph Company Code Machine Information Free 500 6A6 Class B modulator using a single - International Resistance Co. Parts Mfr. Folder Free 493 button mike. The gencmotor is built in Jarnak, Paul Parts Mfr. Illus. Literature Free 505 is for the plate supply and equipped for Karol Radio Products Co. Parts Mfr. Folder 494 relay action for break -ins. It has plug -in Free Kusterman, Oscar B. Set & Mfr. coils and carries two crystals which makes Kit Catalog 10c 487 it possible to switch from one frequency Circular D39 3c 492 to another without loss of time and because McIntosh Electrical Corp. S.W. Diathermy Information Free 499 of the Collins network is enabled to work Mass. Radio School Radio School 52 -page Catalog Free 500 on all frequencies, regardless of length of Midwest Radio Corp. Set Mfr. 1939 Catalog antenna. It is completely controlled by the Free B. C. switch on the hand "mike" and its total Modell's Mail Order 1939 Catalog Free 505 weight is 30 lbs. in a 20 x 10 x 10 inch case. National Company, Inc. Set & Parts Mfr. Catalog Free I.B.C. It uses an ordinary storage "A" battery for National Radio Institute Radio School 64 -page Book Free 449 its power. National Schools Radio School Radio & Television Continuous contact was kept with the Bklt. Free 501 headquarters in the studios of MGM in N. E. Radiocrafters Parts Mfr. Catalog Free 494 Los Angeles via KOU. This ingenious New York YMCA Schools Trade School Booklet Free 500 wrinkle was added to the technique of mod- Radio & Technical Publ. Co. Radio Textbooks Circulan on each Book Free 501 production when ern motion picture a Radio Train. Assn. of Amer. Radio School Book Free 500 director sitting on a Hollywood sound Ralston Record Company stage, supervised an important sea episode Code Course Information Free 500 being photographed 1,000 or more miles RCA Institutes, Inc. Radio School Catalog Free 500 away at sea, by means of short -wave radio- Remington Rand, Inc. Typewriter Mfr. Catalog Free 512 telephone! He could listen to the dialogue Sargent, E. M., Co. Set Mfr. Data Free 497 spoken by the actors in the scene by the Solar Mfg. Corp. Parts Mfr. General Parts Catalog 9S use of a loudspeaker near him. Free 490 The radio equipment worked perfectly Transmitting Catalog 2X Free at all times, regardless of the distance front Condenser Testers Cat. CBCC-1 Free KOU, the land outlet. Perhaps everything Sprague Products Co. Parts Mfr. Catalog Free 492 went so smoothly because of the yacht Sprayberry Acad. of Radio Radio School 48 -page Book Free 495 frequencies used. 2174 and 2738 kc. (138 and 109 meters). They had first tried working Superior Instruments Co. Test Equipment Catalog Free 490 on the 5 -meter band but gave that up be- Teleplex Co. Code Machine Booklet 12 Free 500 cause of too much interference and the Terminal Radio Corp. Mail Order Bulletin Free 494 difficulty in bridging distances. Test Equip. Co. of Amer. Test Equipment Catalog Free 483 This is the first time that an entire movie Trimm company of cast. technicians and directors Radio Mfg. Co. Parts Mfr. Folder Free 499 returned to port with smiles wreathing Triplett Electrical Inst. Co. Parts Mfr. Catalog Free 497 their faces as they contemplated a difficult Van Nostrand, D., Co. Technical Books Catalog Free 489 assignment completed with ease and des- Ward, Montgomery. & Co. Mail Order 1939 Radio Catalog Free 499 patch. And it has definitely been estab- Wholesale Radio Service lished that radio will be used at all times Co. Mail Order 1939 Radio Catalog Free 485 during the filming of sea sequences. 1939 Gift Catalog ' Free

for December, 1938 Please say you saw it in RADIO & TELEVISION 511

www.americanradiohistory.com Answers to QUIZ on page 467 Index to Advertisers 1. b-All others are resistors GREATEST 2. e 3. c & e A 4, aE, bD, dG, eC, eA, IF, gH, hG cB, Aerovox Corporation 503 a term 5. a-e is also general Allied Engineering Institute 488 6. d Allied Radio Corporation 491 BARGAI N 7. a American Microphone Co., Inc. 490 e 8. American Radio Institute 500 9. a Astatic Microphone Laboratory, 505 10. e Inc. in years 11. b & c 10 B 12. b & d 13. aC, bF, cA, dE, eB, fD Barter & Exchange Free Ads 506-509 14. a, 1.434; b, 1.5; e, 1.2; d, 2. Bernard, H. J - 481 15. b Bliley Electric Co. 494 16. d Browning Labs., Inc 505 17. b Brush Development Co., The 491 18. c Bud Radio, Inc 491 19. a & d Burstein-Applebee Co 497 20. b 21. a, mega; b, micro; c, milli; d, micromicro: C e, meters; f, milli. Candler System Co 500 22. c Clough -Brengle Company 497 23. f Commercial Notices 506 24. c Cornell- Dubilier Electric Corp. - 497 25. b at sometimes e) Coyne Electrical School 451

STATEMENT OF THE OWNERSHIP. MANAGEMENT, D CIRCULATION. ETC.. REQUIRED BY THE ACT OF CONGRESS OF AUGUST 24. 1912. Dataprint Company 488 O1 Radio & Television, published monthly at Spring- Dodge's Institute 500 field. Mass., for October 1. 1938. Dutton, E. P., & Co., Inc. 503 of New York State ee. County of New York E Before Isle. a Notary Public in and for the State and Eagle Radio Co 496 county aforesaid, personally appeared Hugo Gernsback, who, having been duly sworn according to law. deposes F and says that he to the editor of the Radio & Television, and that the following is, to the best of his knowledge For Sale Ads 506 and belief, a trite statement of the ownership. management (and if a daily paper. the circulation), etc., of the G NOW AS LITTLE AS aforesaid publication for the date shown in the above caption. required by the Act of August 24. 1912, em- Gold Shield Products 505 bodied in section 411, Postal Laws and Regulations. print- 1Oc a day ed on the reverse of this form. to wit: H I. That the names and addresses of the publisher, editor. managing editor, and business managers are: Pub- Hammarlund Manufacturing Co., Inc 503 Imagine a typewriter that speaks in a whisper! lisher, Popular Book Corporation. 99 Hudson Street, New Henry Radio Shop 492 You can write in a library, a sick room, aPull- York City; Editor, Hugo Gernsback, 99 Hudson Street. Hudson Specialties Company 498 man berth, without disturbing others. And New York City; Managing Editor. H. Winfield Secor. 99 superb performance that literally makes words Hudson Street. New York City; Business Managers, flow from the machine. The Remington Noise- none. by a corporation. its less Portable is equipped with all attachments 2. That the owner is: Ill owned 500 name and address must be stated and also Immediately Instructograph Company that make for complete writing equipment -it thereunder the names and (dresses of stockholders own- International Resistance Company 493 manifolds and cuts stencils perfectly. Furnished ing or holding one per cent or more of total amount of in black with chromium fittings. stork. If not owned by a corporation, the names and addresses of the individual owners must be given. If owned by a firm. company. or other unincorporated con - Jarnak, Paul 505 SPECIFICATIONS cern, its name and address, as well as those of each Standard keyboard. Takes paper 9.5 inches member must be Popular Book Cor- Individual given.) K wide. Standard size. 12 yard ribbon. Makes up poration. 99 Hudson Street, New York City; D. Gerns- to 7 legible carbons. Back spacer. Paper fingers. back. 99 Hodson Street. New York City; H. Winfield Korrol Radio Products Co 494 Roller type. Black key cards with white letters. Seem% 99 'Judson Street, New York City. Kusterman, Oscar B 487, 492 Double shift key and shift lock. Right and left 3. That the known bondholders. mortgagees, and other Right left security holders owning or holding I per cent or more carriage release. and cylinder knobs. of total amount of bonds, mortgages. or other securities M Large cushion rubber feet. Single or double are: (If there are none. so state). None. 499 A brand new NOISELESS neat above. the McIntosh Electrical Corp space adjustment. 4. That the two paragraphs giving Radio 500 typewriter, right off the assembly line. names of the owners. stockholders. and security holders, Mass. School if any. contain not only the list of stockholders and Midwest Radio Corperation Back Cover security holders as they appear upon the books of the Modell's 505 10 -DAY FREE TRIAL company but also. in cases where the stockholder or the time in history you can own a genu- security holder appears upon the books of the company For first the name of N ine Remington Noiseless Portable for as little as as trustee or in any other fiduciary relation. or corporation for whom such trustee is acting, Inc Inside Back Cover 10c a day or $3.00 a month. Think of it! The the person National Company, is given; also that the said two paragraphs contain state- Plans Institute 496 Remington Portable ever built as to National finest at the ments embracing afanes full knowledge and belief National Radio Institute 449 lowest terms we have ever offered. the circumstances and conditions under which stockholders not books National Schools 501 And you don't risk a penny! We will send this and 494 brand new Remington Noiseless Portable for a of the ecompany as trustees. hol d stockeanduse urices a New England Radiocrafters capacity other than that of a bona fide owner; and this New York YMCA Schools 500 TEN DAYS' FREE TRIAL! If you are not believe that any other person, send back. We pay aMant has no reason to satisfied, it all shipping association. or corporation has any interest direct or in- charges. direct in the said stock, bonds, or other securities than R as so stated by him. Cover of copies of each issue of Radio Amateur Course Inside Front 5. That the average number 501 this publication sold or distributed, through the mails or Radio & Technical Publ. Co. FREE SE otherwise, to paid subscribers during the six months Radio -Craft 500 preceding the date shown above Is Radio Publications. 504 With your Remington Noise- (This information is required from dally publicattom Radio Training Assn. of America 500 less Portable - absolutely only.) Ralston Record Company 500 free 19 -page course in (Signature of publisher) -a H. GERNSBACK. RCA Institutes. Inc 500 typing teaching you the before me this 29th day of Rand, Irc 512 used Sworn to and subscribed Remington Touch System, always 1936. by experts. With the help of Sept. MAURICE COYNE. this course you will find typ- (My commission expires March 30. 1940.) S ing the most enjoyable way few York County Clerk No. 562. Sargent, E. M.. Co 497 you ever wrote. Short Wave League 494. 495 Solar Mfg. Corp 490 CARRYING 492 in the cur- Sprague Products Cc. CASE Interesting articles to be found Sprayberry Academy of Radio 495 SPECIAL rent issue of Superior Instruments Company 490 Carrying Case, handsomely covered in DuPont fabric is T included with your purchase. The case makes it easy to Radio -Craft Technifax 488 Teleplex Co 500 take your machine anywhere. the You can use it on trains, or TUBES: New Tubes for 1939. Read about Terminal Radio Corporation 494 on your knees at home. Don't 22 new tubes and 8 ballasts just introduced. Test Equipment Company of America 483 499 delay. Mail the coupon. SERVICING: Making a Service Man's Test Trimm Radio Mfg. Co I. Instrument Co 497 Unit - The Super -Geno -Scope - Part A Triplett Electrical instrument for faster servicing. MAIL NOW compact V Remington Rand Inc. Dept. 300 -12 WAVES: Traffic Lights in Your Car - SHORT for Nostrand, D., Co 489 1 465 Washington St., Buffalo, N. Y. by Radio! A new avenue of business Van Serviceman: helps speed traffic and re- . Tell me, without obligation, how to get a Free the W Noiseless duce hazards. Trial of a new Remington Portable, & Co 499 Free Typing Play Talkies Through Your Radio Ward, Montgomery, including Carrying Case and SOUND: Wellworth Trading Company 503 Course for as little as 10c a day Send Catalog Receiver. 485 - Wholesale Radio Service Co., Inc. TEST EQUIPMENT: Experiments with Multi Name brators- Charles Sicuranza. (While every precaution is taken to insure Address -December issue on all accuracy, we cannot guarantee against the possi- newsstands November I. bility of an occasional change or omission in the City State preparation of this index.)

saw it in RADIO & TELEVISION RADIO & TELEVISION 512 Please say you

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QUALITY THROUGHOUT Look at the HF coils in the NC -100XA above. Each in its own separate compartment in the heavy cast aluminum shield. Each of low -loss construction, painstakingly wound and carefully matched. Each trimmed by an air -dielectric condenser. And each with the shortest possible leads, for NATIONAL the entire coil assembly moves on a track, bringing the desired coil range into position directly below the main COMPANY tuning condenser. Such construction is expensive, but it MALDEN . MASS. is typical of the quality that extends to every detail . . . National builds to a quality standard, for men who judge receivers on performance.

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