Radio News for September, 1935 129

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The invention and development of all - metal tubes by General Electric engineers opened up new possibilities in short -wave FEATURES OF MODEL A -82 and long -wave reception not thought pos- NEW METAL TUBES sible before. So phenominal were the re- More effective shielding and short leads sults obtained that they inspired the design result in higher I.F. gain with greater stability and manufacture of a completely new line -less harmonic distortion on high modulation-less audio gain required - of General Electric receivers. Experi- quieter operation. menters who go DXing with a 1936 Gen- AIR TRIMMER PERMALINER eral Electric Radio will receive a new thrill Accurate calibration and alignment set- in world -wide reception. tings are maintained indefinitely. The receiver operates at maximum performance at all times. SLIDING -RULE TUNING SCALE "Easy to read as a ruler." Only one band visible at a time. Variable ratio drive for easy tuning. "SENTRY BOX" R.F. UNIT All coils mounted directly on band control switch - Minimum length of Leads - Maximum Efficiency. HIGH GAIN I.F. TRANSFORMER Operates at new high maximum efficiency due to perfect shielding of metal tube. HIGH -LEVEL DIODE DETECTION Greater gain in R.F. and I.F. units enables the diode to operate at higher signal level. The result is increased usable sensitivity and better quality of reception. FREQUENCY RANGE 140 to 410 and 540 to 19,500 kc. in 4 bands. And many additional outstanding features. Ask your General Electric Radio Distrib- utor for complete details, or write the Gen- eral Electric Company, Section R -169, Merchandise Dept., Bridgeport, Conn. ELECTRIC RADIO MERCHANDISE DEPARTMENT, GENERAL ELECTRIC COMPANY, BRIDGEPORT, CONNECTICUT

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 129

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J. E. SMITH, Pres. National Radio Institute FREE BOOK jAILC L COUPON Act today for better pay. Act to break away from a low -pay, no- future job. Act to get away from having to skimp, scrape to pay your bills. Mail coupon for my free 64 -page book. It tells you how I will train you at home in your spare time to be a Radio Expert; about my training Good Position Station that has doubled and tripled the pay of many. WSMK $60, $75 a Week "I have a good job, Many Radio Experts Make $40, make a nice salary, and all my success is Consider these facts -think of the good jobs they stand due to N.R.I. 1' am for. Over 17,000,000 Radio sets in use, over 600 broad- operator of Station casting stations, over 40 large manufacturers of Radio WSMK. I highly sets, over 3,000 manufacturers of parts, over 100 Police recommend the N.R.I. Departments Radio equipped, airplanes and airports Course. It enabled me AT HOME to pass the Govern- Radio equipped. Thousands of ships touching every sea- SAVE MONEY -LEARN ment examination for port of the world are Radio equipped. Over 35,000 an operator's license." stores selling sets and parts, about 2,000,000 autos Special Equipment Gives You JOHN HAJDUK, Jr., 21 Gerard Radio equipped and about 20,000,000 unequipped. Loud Avenue, Southern Hills, Dayton, speaker systems wherever people gather, indoors and Practical Experience Ohio. outdoors. Commercial Radio stations dotting our coast $18 a Week in Spare Time lines. Radio a big industry -is growing bigger fast. A Hold your job. No need to leave home and spend a "Although I am do- few hundred $40, $60, $75 a week jobs have grown to lot of money to be a Radio Expert. I'll train you ing only spare time thousands. quickly and inexpensively right at home in your Radio work, I have You a high school or college averaged $18 a week. spare 'time. don't need I recommend N.R.I. Get Ready Now for Jobs Like These education. Many of my successful graduates didn't training. It is cer- finish grade school. My practical. 50 -50 method of tainly a completo A spare time or full time service shop; installing, main- training -half with lessons, half with Radio equip- Course. In a short taining, operating -broadcast, aviation, commercial, ment -gives you broad practical experience -makes time, it will take a ship, television and police stations. A Radio retail busi- learning at home easy, fascinating, practical and man, give him a maintaining, servicing, sound fundamental ness of your own. Installing, rapid. There is opportunity for you in Radio. Old training in Radio theory, prac- loud speaker systems. A service or sales job with a jobs are becoming more complicated-many need tice and design." STEPHEN J. store or jobber. I'll train you for good jobs in every better trained men. New developments are making DRAPCHATY, 407 Wunderlich branch of Radio. new jobs. Short waves, loud speaker systems, police Ave., Barberton, Ohio. Radio, auto Radio, aviation Radio, television - Nets about $50 a Week Many Make $5, $10, $15 a Week Extra Radio's newest uses are covered - by my training. besides Sales in Spare Time While Learning Here's a field that's growing. It is where you find 'iI have been getting growth that you find opportunity. along fine. I aver- Every neighborhood can use a good part time service- age ten calls a week, man. I'll start giving you special instruction material, which nets me about plans, ideas, the day you enroll, for making money in $50, not counting time. Get my book how many of my stu- profits on sales. I spare -read have serviced almost dents make $200 to $1,000 in their spare time while every make of set and learning. have earned more Stanley Tulk, 2705 Hector Street, Montreal, Canada, than I ever expected. writes -"I have been doing so much service work I have doubled I owe my success to haven't had time to study. 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My book of information on other F.. super-heterodyne, ll -wove, and Radio's spare time and full time opportunities types of sets. And c roes reference system gives you the probable cause and quick is free to any ambitious fellow over 15. Read way to locate and remedy these set troubles. what Radio offers you. Read about the train- A section devoted to receiver J. E. SMITH, President p. agnment, balancing, neutraliz- ing I offer you. Read letters from graduates - ing testing. Get cooupon. Free. No National Radio Institute, Department 5JR áai ó what they are doing and making. There's no obligation. Mail coupon in an envelope or Washington, D. C. paste it on a postal card -NOW. Il Dear Mr. Smith: I want to take advantage of your Spe- J. E. SMITH, President cial Offer. Send me your two books, "Radio Receiver ll Troubles -The Cause and Remedy" and "Rich Rewards in National Radio Institute, Dept. 5JR Radio." I understand this does not obligate me. (Please print plainly.) Washington, D. C. NAME AGE ADDRESS lesfiea WayW y to gElIERp Ay CITY The STATE 14X -1

www.americanradiohistory.com Edited by LAURENCE MARSHAM COCKADAY

S. GORDON TAYLOR WILLIAM C. DORF Managing Editor Associate Editor

JOHN M. BORST JOHN H. POTTS Technical Editor Assoc. Tech. Editor

JOSEPH F. ODENBACH Art Editor Vol. XVII September, 1935 No. 3

keading Cuide 1 Radio Facts and Oddities H. T. Elmo 132 2 Dots and Dashes News Staff 134 to this Issue- 3 Metal Tubes c Editorial 136 4 Radio in the C.C.C. Stephen C. Manning 137 As a matter of convenience for 5 those having specialized interests What's New in Radio William C. Dorf 139 in the radio field, the following 6 The Navy's Voice Searchlight The Editor 140 lists the articles and features in this issue, classified under 14 7 The "Normandie's" Radio Equipment Jean Ledoux 141 heads. The numbers correspond 8 Television in Canada Oakille 142 with the article numbers in the Rupert Table of Contents on this page : 9 Building the Super DX-8 John M: Borst 144 AMATEURS -3, 5, 8, 9, 12, 13, 14, 10 A Superhet 15, 16, 17, 24, 26, 27, 31, 34, 36. DeLuxe (Part 3) B G. Valentine 145 BROADCAST FANS -3 4, 5, 7, 8, 11 A 19-Tube 10, 11, 19, 21, 28, 30, 32. Laboratory Super McMurdo Silver 146 DEALERS-3, 5, 8, 9, 12, 16, 18, 20, 12 21, 22, 24, 28, 33. A New "Ham" Receiver John Strong 147 DESIGNERS -3, 5, 6, 8, 11, 17, 31, 13 Making 34. a "CQ" Key Ed. Glaser 147 DX FANS -5, 10, 11, 28, 30, 34. 14 The "Ham" Shack Everett M. Walker 148 ENGINEERS -3, 5, 6, S, 11, 17, 31, 34. 15 Code Practice Schedules Amateur News 149 EXPERIMENTERS -3, 4, 5, 6, 8, 9, Editor 10, 11, 12, 13, 15, 17, 18, 19, 21, 16 Testing a 23, 24, 26, 27, 29, 30, 31, 33, 34, 36. Communication Receiver L M. Cockaday 150 MANUFACTURERS -3, 5. 6, S. 17 Impedance- Matching Calculations (Part 2) C. A. Johnson 151 OPERATORS-5, 6, 7, 12, 13, 14, 15, 16, 24, 26, 34, 35. 18 New Profits for Servicemen Barron R. Mace 152 SERVICEMEN -3, 5, 6, 8, 9, 12, 17, 18, 20, 21, 22, 28, 29, 31, 33, 34, 36. 19 "Seeing" Radio Signals SET BUILDERS -3, 5, 6, 8, 9, 10, 11, Samuel Kaufman 153 12, 17, 18, 21, 23, 24, 27, 29, 30, 31, 34. 20 Service Contest Awards Zeh Bouck 154 S. W. FANS -4, 5, 7, 8, 9, 11, 12, 14, 15, 16, 23, 24, 25, 26, 27, 28, 29, 21 An Automatic Time Switch John H. Potts 155 34. STUDENTS-3, 5, 6, 7, 8, 9, 11, 12, 22 Service Work in a Small Town Fred E. Kunkel 155 15, 17, 19, 20, 31, 33, 34, 36. TECHNICIANS -3, 5, 6, 8, 9. 10, 23 The DX Corner for Short Waves L M. Cockaday 156 11, 12, 17, 18, 20, 21, 22, 28, 29, 31, 33, 34, 36. 24 World Short-Wave Time -Table The Editor 158 25 Short -Wave Club News News Staff 161 Next enfOnth 26 World Short -Wave Station List The Staff 162 Constructional articles on the 27 Capt. Hall's Short -Wave Page Horace L. Hall 164 Potts "Supersensitive V.T. Volt- 28 Testing a 5 -Band Super Associate meter" and the "RADIO NEWS 2- Editor 165 Volt DX'ers Super" will appear in 29 A S.W. Signal Booster Robert Hertzberg 165 the October issue, without fail. It was planned to include both 30 The DX Corner for the Broadcast Band S Gordon Taylor 166 of these articles in the present 31 Design of Crystal Band 4) issue, but unavoidable circum- Filters (Part W. W. Waltz 168 stances prevented the carrying 32 Backstage in Broadcasting Samuel Kaufman 170 out of this plan. Preliminary descriptive articles on these two 33 The Service Bench Zeh Bouck 172 units appeared in the August issue. Another feature of the Oc- 34 The Technical Review Robert Hertzberg 176 tober issue will be an article on 35 QRD? By adapting standard receivers for G. Y. 178. headphone operation, with spe- 36 Students' Radio Physics Course Alfred A. Ghirardi 180 cial emphasis on the money- making aspect for servicemen. 37 The Radio Workshop 182

Published Monthly by Teck Publications, Inc., Washington and South Avenues, Dunellen, N. J. Lee Ellmaker EDITORIAL AND EXECUTIVE OFFICES and President Treas. 461 EIGHTH AVENUE, NEW YORK CITY, N. Y. 25c a Copy, $2.50 a year, B. Holcepl Entered as second class matter at the Post Office at Dunellen, $3.00 in Canada, $3.50 in Secretary N. J., under the . act of March 3, 1879. Copyright, 1935, by Foreign Inc., in U. S. and Canada. All rights reserved. Countries. Sub- H. D. Crippen W. P..Jeffery Teck Publications, scribers are notified that Advertssing Management Registration of title of this publication as a trade mark applied for in United States Patent Office. Printed in the United States change of address must reach Virgil Malcher of America. The' contentssof this magazine must not be repro- us five weeks in advance of 205 W. Wacker Dr., Chicago duced without permission. We cannot be responsible for lost the next date of issue. Western Representative manuscripts, although every care is taken for their safety. 130

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 131

CABLE ADDRESS "CHIRACLUB" CHICAGO SNORT WAVE RADIO CLUB CHICAGO, ILL, U. S. A.

ALFRED G. LUOMA GRANO PEMC WINNER SCOTT 1932 385155 Nohrt KedvJe MEMBER'S eA e., Clinlo CORRESPONDENCE T4. AVENUE 4303 June 25, 1335.

McMerdo Silver Corporation, 3354 N. Pauling Street, Chicago, Illinois.

Dear Sirs:

Since I have put had the new MASTERPIECE it to a very IV r have severe test, and ses anything on will say it far the present market. surpas-

The tone quality, is excellent, both high fidelity and it reproduces and sharp, they were the piano being played and organ as in the same room. if The noise level antenna is very low disconnected to signal ratio. trace I heard Europoans With of noise. without the slightest

The bass and wonderful, treble tone controls both for tone are certainly for controlling control and noise speech from suppression, also lated short a lot of the wave stations. more poorly modu-

The wreak small stations ter volume and come in now quality; all with much bet- high wave length the bands are very band on which hot, even the I tuned it. I heard Alaska The broadcast the first night short wave band is very good, bands are what and the three . . When the first Silver I would call perfect. Having had other two of your MASTERPIECE IVs went into custom built previous sets, sets as well, and many this one. I know what action a month and a half ago, to expect from

Allow me to our feelings were those of a it most congratulate you certainly on the MASTERPIECE proud parent. We knew, after deserves its name. IV - the most rigid tests in our Sincerely, own laboratories, that the new fred G. Luoma MASTERPIECE IV could out- perform any other all -wave re- ceiverin existence, at anyprice. Now, reports pouring in from enthusiastic owners prove be- SILVER MASTERPIECE IV yond a shadow of a doubt that is definitely the finest radio of all time! Arthur Maitland, of the Lamb's Club, New York City, 25 NEW, EXCLUSIVE FEATURESI says "The tone is beautiful; in fact, as fine as I have ever heard -and I have heard most all of them, even The Silver MASTERPIECE IV introduces 25 entirely new the $900.00 ones. I really think it is a fine job -far engineering advancements and refinements, including and above anything you have ever done before. In one Lowest Inherent Noise of any radio made today. evening heard 51 stations on D (25, 31 Two Tuned R.F. Stages on all 5 tuning bands. band" and 49 All R. F. and I. F. circuits air tuned thruout. meter broadcast bands -just off Times Square in d.c. Controllable Selectivity. New York). William Seaman, of Hamburg, Pennsyl- Double High Fidelity on both foreign and local. vania, writes "Say, is the Four a Masterpiece! " And Complete Professional Flexibility. from Alfred G. Luoma of Chicago, winner of an Inter- 19 Tubes that do the work of 23. . And in addition -the new Silver MASTER- national DX Contest and champion DXer, comes a letter PIECE IV retains those important basic features which made its three precedessors the which is reproduced herewith. overwhelming choice of :he most critical users FOR --1 - engineers, professionals, musicians - the 10 -DAY TRIAL r -MAIL COUPON BOOKI world over. . . . 5 -YEAR McMURDO SILVER CORPORATION 3352 N. Paulina St., Chicago, U.S.A. GUARANTEE Send Free "Blue Book" with complete specifications Send today for of Silver MASTERPIECE IV, also details of FREE TRIAL OFFER and 5 YEAR FREE 32 -page GUARANTEE. Book which tells Name McMURD® SILVER CORP e the complete Division of G.P.H., Inc. story, with de- Address 3352 N. PAULINA STREET, CHICAGO, U. S. A. tails of 10 Day Trial Offer and City State 9RN 5Yr. Guarantee. L j

www.americanradiohistory.com FACT4 ct ODWES emooc. (Send in your Radio Oddities to "Elmo" and see them illustrated) /I

.,0 11110 nniuui.,,.n, '/I1 intnwm

G>rEL ""5-;E WORLDS OrRECVFIERTRF,REcENTLY ife'\,RES\OE 5(EN `to DEMONSïRA`(tD AT MILWAUKEE, HAS AN OUTPUT oF /,DO4, Ró UNk-ES E WATTS AT 2.5, 00o YOI.YS, D.C. YT 1S eATAßLE OF T N(N151-F. r GROUNDS REcTIFY1NG EoUGH ELECTRcAL. ENEtZGY To LI 7H 1 EVERY HOME w AN AvERAGE Cl`(Y OF 65, o o 0 P.EOP !!

CITRARY TO A POPULAR NOTION), HE USE OF ULTRA HIGH FREQUENCY RA ®(O DOES NOT AFFECT WAVES TO KILL GERel S RROIo THE' WEATHER ...... BUT THE TEETH;VJAS RECENYL' OFDECAYINJG WEATHER AFFECTS RADIO, At4NOUNCE0 `-NE T ETN WERE (RESULTING STATIC EXPOSED FOR PERIODS OF S MINUTES IN LI TO AN HOUR /N fr AND FADING

132

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 133

THE NEW WESTON MODEL 770 TUBE SELLER eith COUNTER OR PORTABLE USE

Here's real merchandising appeal in a real tube neon indication of condenser leakage if desired . . checker. This new Weston Model 770 sets a new stand- makes individual tests on all plate circuits ... tests ard in tube selling and servicing; yet, it's priced so all tubes, including the metal tubes, and has many every dealer and serviceman can afford it. In fact, other exclusive features. Ready for immediate de- with its striking design and rich three -color combi- livery. Get the facts on Model 770 before you buy. nation, no dealer selling tubes can afford to be without See it at your dealer's, or return the coupon for com- its customer appeal. And as a tube checker, it's a plete data Weston Electrical Instrument perfected emission type which actually tests tubes Corporation, 615 Frelinghuysen Avenue, Newark, under load ... provides a neon short check ... a New Jersey. r WESTON ELECTRICAL INSTRUMENT CORP., 615 Frelinghuysen Ave., Newark, N. J. ; Send me complete data on Model 770 and other WESTON radio instruments. WE S TON Name Address adio Instruments ;

www.americanradiohistory.com 134 RADIO NEWS FOR SEPTEMBER, 1935

CHECKING TELEVISION DOTS PROGRAMS ABROAD and Here is the program manager of the Berlin television station selecting the feature picture-stories for the coming - - DASHES week. The test desk is a complete transmitter and receiver so that the Short but Interest- pictures which are viewed in the FIELD TESTS small central screen are seen just as ing Items from the DIRECTS they would be received in the home. Month's Radio News IN AMERICA Dr. W. R. G. Baker, vice -president the World Over and general manager of R.C.B., TELEVISION is a word that one heads a committee for directing the hears, now, on the lips of every radio- company's television research and field man. The whole world seems to have films. He is also credited with saying that tests. Dr. Baker is shown examining gone "television crazy" and rumors of television may mean an audience of twenty one of the huge Iconoscope tubes that one thing and another about television or thirty million persons reached in two will be used in these tests. Above: are being passed back and forth. or three nights, instead of a seven to the inter -company television commit- twelve months period. tee; left to right: C. W. Horn, re- THERE is no doubt but that tele- According to the Television Times two of N.B.C.; J. C. new search director the vision is worrying the moving -picture television companies have been organ- Warner, vice -president, Radiotron Di- industry today, just as "sound" wor- ized in Detroit to start production on E. W. Engstrom, television receivers in the fall. vision of R.C.B.; ried it in 1927. Mr. H. R. Lubcke, Direc- manager in charge of the R.C.A. will use the A. T. and T. coaxial assistant tor of Television for the Don Lee, Broad- television development of R.G.B.; Dr. casting System, as guest speaker of the cable from Philadelphia to New York to relay television to the Empire State Build- C. H. Taylor, chief engineer, R.C.B. Research Council of the Academy of Mo- R. R. ing for field tests in early 1936 or before. Communications; Beal, research tion Picture Arts and Sciences recently director, R.C.B.; O. B. Hanson, chief said, "The hue and cry that television will A report that they have in process of construction several hundred television receiv- Engineer N.B.C.; Dr. Baker, and H. destroy the motion picture industry is need- K. Norton, assistant to the president lessly disturbing. Our television- motion- of R.C.B. picture activities have long since passed TELEVISION MOVES AHEAD the stage of conjecture. As early as 1932 At left: Demonstrating the Baird ing sets has been "going the rounds ". It we were making special tests on special home receiver with an actual picture is confirmed that the R.C.A. has formed an films for television on the lot of a major of Mickey Mouse being received and inter -company committee for direction of producer." viewed plainly in the mirror. At the company's television activities. This Sam Goldwyn, noted film producer, is right: The latest Farnsworth equip- committee, named by David Sarnoff, quoted as stating that television will use ment for taking television "shots" President of the Corporation, is headed by up a motion picture in one night and thus being demonstrated by George Sleeper Dr. W. R. G. Baker, Vice -President of the might create a greater demand for good of the Farnsworth Television Company. R.C.A. Victor Division. Five other leading

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 135

NO MORE SHOUTING AT SEA The use of the old -fashioned mega- phone and the bellowing human voice faces extinction in communicating be- AN ELECTRONIC "FRISKER" tween nearby boats or vessels at sea. A guard removes a concealed weapon, A new device which accomplishes the presence of which was made this result, electrically, may soon be known by a new "gun detector" de- used on all ships. (Story on page 140.) veloped by Dr. David Luck, research engineer, of Camden, New Jersey. ready completed their new ultra -high fre- Anyone passing through a protected quency transmitter for use between 42,000 doorway of this kind carrying sizeable and 56,000 kc. They have been demon- metal objects, sets off an alarm and strating television in their New York isolates the room by automatically studio for some time now. closing steel doors. The device might Another rumor regarding RCA is that be used at the entrances and exits of their largest "test" receiver for television AID TO THE DEAF AND DUMB banks. uses a cathode -ray tube and gives a pic- This new apparatus will help teach- ture 8 inches square. It will really con- ing of speech to the deaf and dumb. men who will also serve on the committee tain three receivers, one for sight and Dr. F. Y. Hunt of the Cruft Labora- are R. B. Beal, RCA Research Supervisor; another for sound (both ultra -short waves) tory, of Harvard, is shown pointing C. W. Horn, Director of Research and and the third receiver will be for ordinary to the frequency meter which will in- Development of the N.B.C.; O. B. Hanson, sound broadcasts. A complete set will dicate when a deaf-and dumb person, Chief Engineer of the N.B.C.; C. H. have as many as fifty tubes, if this rumor speaking into the microphone, makes Taylor, Vice -President in charge of engi- is correct. Still another report (that was the correct sounds for a word, spoken neering for RCA Communications, Inc., vehemently denied by officials) was that previously, by a normal person. and J. C. Warner, Manager of the Radio - this company had ordered many thousands tron Division. Dr. Baker said the com- of television cabinets for fall delivery. (Editor's note reported to have concluded similar ar- mittee was confident of ultimate tele- -We are printing these ru- rangements mors and reports simply with a view to with Baird Television, of Eng- vision results, although it would take some land, whereby patents and technical time iron clearing the air, but it is also our feeling data to out some of the wrinkles for will be exchanged. The move is inter- commercial television broadcasting. that television is fast looming up as a force in radio that may start a trade preted to mean that both Baird and William Peck, who is now broadcasting Farnsworth will revival as far- reaching in its effects as that manufacture television television in Canada, may soon start opera- apparatus incorporating the best features tions in the United States, according to a of regular radio broadcasting, in 1919, reliable report. A similar statement has 1920, 1921, and 1922.) (Turn to page 181) been made regarding the activities of Exchange Television Rights Harold Donle, well -known for a long line RADIO IN TASHKENT of television experiments. The First Na- PHILADELPHIA, PA. - The Farns- Radio now entertains guests, shown tional Television of Kansas City has al- worth Television Corporation, which only below, instead of native singers and recently arranged a tie -in with the Fernseh dancers in a tea house in far -off Uz- DISAPPOINTED PILOT Television interests of Germany, is now bekistan, U.S.S.R. Capt. Orvil A. Anderson, who was to have piloted the REAL "AIR COP" DIRECTS TRAFFIC National Geographic -Army Air Corps stratosphere flight, To test traffic direction from the air, Harold Fowler, Dep- inspecting the gondola of the uty Police Commissioner of New York, recently flew over Explorer II, which, unfortu- highways leading to the city and gave rerouting directions nately, burst its gas bag just to police stations via radio. before taking off.

www.americanradiohistory.com OF COURSE! Everyone will eventu- opinion, it does not have to be manufactured ally use metal tubes. They do offer in the old way, "just like a lamp." It may an improvement in design and in be considered as a "part" just as a condenser manufacturing methods for receivers. or a resistor is a component part of a radio As early as 1933 RADIO NEWS predicted that set. The ordinary home owner would never metal tubes would simplify and improve set consider taking out a resistor or a condenser construction. And again in 1934 RADIO if his set failed. Why? He wouldn't know NEWS said, "Eliminating the glass bulb is a what part of the set it was and he would not radical step that may improve radio impor- be able to get it out easily. Condensers do tantly. Tubes such as these may make pos- not have sockets and plugs to connect them sible much smaller but much more powerful into a set. They are not readily replaceable. receivers in the future." After all, metal Even coils are now being made as regular tubes are and have been standard for broad- components of a receiver and plugs and cast and commercial transmitters for many sockets for coils are not used in most of to- years so that the use of this principle, "in day's sets. Sockets and plugs have insula- miniature," for receivers cannot be very far tion and insulation has some loss of radio wrong. But some manufacturers may hold frequencies. So why not also make future back for a time like the auto makers who tubes as units that can be built right into the said, "No four -wheel brakes on our cars;" set to stay! No sockets -no plugs -and and then put them on anyway in less than a lower capacities and lower losses! If such a year! set went wrong the serviceman would repair it and handle tubes just as he now does re- ARE METAL TUBES BETTER or worse placement condensers and resistors. At once, than the older type? Lots of people this would be better service to the set owner, ask this. The answer is: Metal tubes use the more opportunity for the serviceman and all same filament, the same grid electrodes and sets would be kept in better shape! Tube plates as the older type. So the functions of manufacturers could make an honest profit, these integral parts should be exactly similar. for their products would no longer be the But the new tubes have a metal cylinder victims of price- cutting and unfair competi- rather than a glass tube and the cylinder is tion by sales to set -owners who cannot tell a smaller. It can be used as a ground. This good tube from a bad one, and every set sold eliminates the use of extra. shielding and sim- would need to have a complete set of new plifies set construction. Then, again, the base tubes to power it. Set manufacturers would of the tube is smaller and ,capacity and leak- also profit because servicemen would be on age can therefore be reduced. So there is no hand to tell set owners when their set became inherent reason why metal tubes should be obsolete and could sell them a new one rather worse than their predecessors and a number than have the owner blindly remove a few of reasons why they can be better. tubes -take them to a dealer, get new ones and put them back into the old set which WHAT ABOUT THE FUTURE of won't work half well -even with the new metal tubes? The future, we again ones! After all, metal tube sets of this type, predict will be radio's future! Metal tubes for both radio and television, could sell as will be found in future radio receivers as they complete replacements, today, if the public are now in transmitters. There may be more were educated to expect a saving in radio, by metal -tube types added to present types and yearly replacement, just as they do in the actually there is no reason why metal tubes purchase of automobiles. should not be made even smaller and still At any rate, no matter how you look at it, more efficient! The radio vacuum tube is there's a great future for metal tubes and really a thermionic relay and, in our humble metal tube developments!

136

www.americanradiohistory.com September, 1933

l V

in the

How short -wave radio is playing a big part among those scattered "Robin Hoods" of the Civilian Conservation Corps, not only from the standpoint of communication between camps, but also as a means of communication back home. It is just another case of how short- wave radio is pouring world news into those out -of- the -way places.

FNCAMPED in a forest in Stephen C. Manning camps' commanding officers and work Idaho were 200 boys of a superintendents have gotten equip- Civilian Conservation Corps ment into action and are "on the air." company, uprooted from metropolitan New York. The Today (a different picture than that when, nearly two tall trees were not the towers of Manhattan and the lads years ago, the first contingents of the C. C. C. penetrated were homesick. One of the Army Iieutenants, an old the forests) hundreds of camps are hooked together by time radio amateur, tossed to- short -wave radio and are in gether a transmitter and re- REPORTING BACK TO CAMP communication with Army ceiver, and under a portable A C. C. C. radioman operating one of the Forest headquarters and amateur call, immediately opened the Service's semi- portable transceivers. The mule carries stations in every part of the floodgates to a steady stream the equipment, 'which can be unloaded and set in country. of messages between nostalgic operation, in a jiffy. "bush marines" and their Short Waves families back in the Big City. The Army was quick to see A Vast Project the value of short -wave com munication in its administra- This is but one phase of tion of the C. C. C. camps. In the Nation's newest wholesale April, 1932, the Ninth Corps experiment in short-wave Area found its problem to be communication which is now this: its bailiwick stretched taking place among the 1651 from the Canadian to the camps spotted throughout the Mexican borders, and from National Forests, National the Pacific to the Rockies. Parks, on private farms, at the How could San Francisco bottom of canyons and atop headquarters keep in close high peaks -in fact, under touch with 459 camps (the every climatic and geographic Ninth Corps Area's alloted condition in the United States. number) dotted over this vast The U. S. Signal Corps, the area? Radio was the solu- Forest Service and the Na- tion, of course; but with the tional Park Service are spon- increased traffic over the reg- soring a more official brand of ular Army networks, the nec- experimentation, while hun- essary men to do the job dreds of individual amateurs could not be spared. So Maj. ranging from the lowliest Gen. Malin Craig, then corn - "civie" (the Army would call manding the Corps Area, him a buck private) to . the upon the recommendation of

137

www.americanradiohistory.com SEPTEMBER, 1935 . 138 RADIO NEWS FOR

with its district net control station, and operators are regularly on duty operat- control station at Corps ing a Signal Corps field transmitter; a main net other Area Headquarters in Baltimore. Opera- one handles the key while the tion throughout the complete net-35 turns the crank on the hand- driven gen- begun April 10, 1934. erator. Justice is seen in the ruling stations -was their These 25 -watt camp stations, using that these two operators reverse typical amateur apparatus, in the day- respective jobs on each of their hourly operate on Army frequencies contacts with the other stations. time in (4305 kilocycles for the Virginia -Mary- C. C. C. radiomen have been active land net and 4445 kilocycles for the two other official fields -the Forest Ser- Pennsylvania loop. Official traffic is vice and the National Park Service. Last handled under four -letter calls begin- summer, while the Forest Service was ning with WVH. devoting much research to the develop- At night, these stations turn to the ment of lightweight, portable equipment amateur frequency bands, and use for fire -fighting duty in the vast north- amateur call letters. While in that western forests, came the fierce fire sea- state, they handle private messages son of 1934. Maj. Evan Kelley, For- from enrollees to and from their home ester of the Service's "Hottest Region," towns, and indulge in all varieties of threw picked companies of C. C. C. amateur short -wave work. (Each camp men into the front line of attack against is supplied with its own copy of RADIO the walls of fire sweeping over terrain NEWS for its leadership in the short- impassible except by mule back. The wave field so that each camp will have new Forest Service radio sets were at its fingertips the latest technical and given their baptism of fire -and many operating short -wave information.) of them were operated by C. C. C. amateurs fortunately familiar with Practical Training short -wave radio. "This," said 1st Lieut. Harold O. In National Parks Bixby, A.A.R.S. Liaison Agent, "was Park Service, also is highly desirable . . . because the opera- The National tion of an amateur station would build going in heavily for radio in administra- up considerable interest among the en- tion and fire-fighting communication. rollees and work up worthwhile educa- Each National Park is alloted a fre- tional and recreational activities around quency in which its fixed and portable the radio station. Radio classes have stations operate: C. C. C. members A REAL PORTABLE been formed, with the operators as in- have aided greatly in the development This portable transceiver, being toted structors, and reports show that some of equipment. Two enrollees, gradu- by a forester, is used for penetration of these embryonic operators may be ates of technical school and working on rugged country. into extremely able to operate the stations before their their Master's degrees in radio engineer- enrollment expires." ing, helped perform many valuable ex- All of the stations in the Third Corps periments in Rainier National Park. -enrollee was a valu- Signal Officer, authorized the enroll- Area are also members of the Army Another amateur his in (Turn to page 164) ment of unemployed members of the Amateur Radio System, and hold regu- able assistant Army Amateur Radio system -a chain lar drills in that organi- of amateurs which forms an auxilliary, zation, according to A C. C. C. -ARMY NETWORK STATION volunteer short -wave network to the Capt. Rex W. Minckler, This is Station WPHN- I178LYK, a station of the Signal Corps' own hook -up. The ama- Liaison Officer in charge Third Corps Area, located at Camp Milray, Penn- teurs agreed to the proposition that of the A.A.R.S. in sylvania. C. C. C. men built the table and chair, which would be signed Washington. are in the radio corner of the administration building. 12 A.A.R.S. members stations in would be trans- The A.A.R.S. again This is standard equipment for all the 35 up; their equipment this loop. ported and installed in the various dis- steps into the picture in trict headquarters at the Army's ex- the Mid -West, where in pense. This net -operating on 3497 the Seventh, and to a and 6990 kilocycles, under four -letter lesser extent, the Sixth calls beginning with "WUB " -is still in Corps areas state C. C. C. efficient operation. In the other Corps networks have been Areas, throughout the summer and formed. These operate winter of 1933, most of the pioneering under amateur and work in C. C. C. short -wave communi- special Army calls, with cation was done by individual amateurs A.A.R.S. supervision, in the camps. But the beginning of the handling both official second six -month's enlistment period C. C. C. business and beginning October, 1933, saw an influx private messages from of 32 more companies into the Third and to enrollees. In the Corps Area (Maryland, Virginia, Penn- Seventh Corps Area, the sylvania and the District of Columbia), Minnesota and South bring the total number of camps to 185. Dakota networks are Many of these were isolated; roads perhaps the most active, were practically impassable in the with other states rapidly winter. establishing new stations for efficient state -wide The S. W. Network coverage. The need for radio communication Less formal is the was apparent. It was felt that the Ninth small set -up reported in Corps Areas' idea was a step in the Arizona, in the Eighth right direction, but that the Govern- Corps Area. Reports ment should provide the short -wave come of a small loop of equipment. So the Third Corps Area three short -wave sta- was inaugurated. It was divided into tions, located at Tucson, two district nets -one for Pennsylvania Ashdale and Globe. In and another Virginia -Maryland, each the Tucson camp, two

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 139 WHAT'S

an RADIO By William C. Dorf Attractive Battery Operated Console The photograph below illustrates the new American -Bosch model 376N five - tube superheterodyne receiver for use in unelectrified homes. The set can be em-

EXPLAINS FARNSWORTH'S LATEST TELEVISOR George Everson is shown demonstrating to Mrs: Gordon Coyell the new Farns- worth cathode -ray television instrument to be used for British Sight broadcasting.

metal tubes now on the market, also has tional Universal recording equipment in- provisions for various combinations for cludes a recording amplifier, aluminum any new tubes which may be introduced blanks and silveroid discs, together with in the future. The meter itself is of mod- sapphire, bamboo and trailing shoe needles. ern rectangular shape with an easily read scale. Something New in Loudspeakers New Line of Glass Tubes A magnetic type reproducer with no solder connections in the mechanical link- Interchangeable With ages, fewer parts and extremely rugged Metal Tubes construction has just been announced by An announcement was recently received Wright -De Coster, Inc. This Hyflux mag- from the Arcturus Radio Tube Company netic speaker is designed to have an unusually ployed with either the air -cell, standard that they are bringing out a line of tubes fine frequency range and to provide tone quality dry -cells or a 2 -volt storage battery. identical in electrical characteristics and comparable to the pin connections to the metal tubes, but electrodynamic type reproducer. A New Universal Tube Checker having a glass envelope. These tubes carry the same Receiver Features Dealers and servicemen will be inter- type numbers as the metal tubes Expert ested in the new Weston tube tester which except the letter "G" is suffixed. The new Workmanship "G" line will enable set manufacturers represents a striking departure from former to The Stromberg- Carlson model 58W low- proceed with the design of metal tube sets types both in appearance and electrical de- boy receiver covers from 540 to 18,000 kc. without ' sign. It has socket mountings to take care waiting upon the present limited in three bands. Six tubes production of metal are employed, of all pin combinations for all glass or type tubes. and a 10% -inch dynamic type speaker. Precision Recorder Several new and unusual features are in- corporated in the design of this set, out - The Universal Microphone Company (Turn to page 174) announces a professional recording machine featuring rim drive and countershaft which makes it possible to make recordings at 78 or 33/ r.p.m. on 50- or 60 -cycle current. The machine is set for 108 lines per inch, but it can be changed to any number of lines desired. The special power cutter has screw adjustments for damping. Addi-

www.americanradiohistory.com 140 RADIO NEWS FOR SEPTEMBER, 1935. PROJECTS SOUNDS LIKE HAMMER BLOWS Here is the world's most powerful loudspeaker, that is capable of throwing the human voice in intelligible speech to a distant point miles away. The sound leaves the speaker with the force of a 50 -pound sledge- hammer blow, making a sound at the mouth of the The speaker 1,000 times as strong as the roar of Niagara Falls. IJ.S.N avy's VOICE SEARCHLIGHT

By The Editor

great distances but it will fine duralumin ribbon .01 inches thick. carry speech over these When driven at maximum power the distances intelligibly. This diaphragm generates an actual sound is due to the special design pressure of better than I pound per in which clarity is obtained square inch and the magnetic force to by arbitrarily and de- set up this pressure is equal to about liberately sacrificing 50 pounds. Another way of saying this straight -line frequency re- would be that the sounds leave the dia- production and by focusing phragm with the force of a 50 -pound on those frequencies which sledge hammer blow. The speaker and tend to make speech more its reflector, combined, are 30 inches readily understandable. in diameter and 30 inches deep. The This enables the output of reflector is made of cast aluminum and ANEW ,loudspeaker or what may the device to pierce through a tumult weighs 125 pounds. The speaker unit giant "voice search- of other noise and reach ears already itself weighs 375 pounds. Both the be termed a mounted light" has recently been made carrying deafening burdens of sound speaker and the reflector are on and speaker can for the U. S. Navy and the with an overpowering amount of crisp, a swivel tripod the available be pointed easily in any direction. Coast Guard. It is so powerful that it understandable speech. The loud- can reproduce the human voice 1,000,- speaker, itself, is of a special "moving for Speech strength and coil" type. A coil of wire attached to Used 000 times above normal of sound in a "beam" the diaphragm is suspended in a pow- It is reported that this is the type can project the the Navy Department in- of several miles. Com- erful, steady magnetic field. The coil device that over a distance tends to make avail- (Turn to page 188) pared with an ordinary loudspeaker this is 8 inches in diameter and is made of new device gives the Navy the most as it is at powerful . "voice" in the world, least 500 times more powerful than the standard loudspeakers ordinarily used for this purpose. The new device was developed by engineers of the Western Electric Company and is capable of reproducing intelligible speech with more volume than a clap of thunder. When measured directly in front of the horn, the maximum sounds are 1,000 times louder than the roar at the foot of Niagara Falls. This gives some idea of its tremendous power. Wide Usage Predicted Enormous crowds of people extending way beyond the range of existing loudspeakers could be handled easily by means of the new speaker. Such groups of people would include outdoor mass meetings ; soldiers moving en masse: fire fighters within burning buildings; rescuers at sea, from the rescue ship to the distressed crew or to those in lifeboats; searching parties and expeditions; at yacht races and other outdoor groups or sports. The unit not only will carry over

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 141 The New Queen of the Seas Broadcasts to Two Continents

The Radio Equipment of the "NORMANDIE" By Jean Ledoux

THE S.S. Normandie, world's of wirelessed news dis- largest liner and winner of the patches from corre- blue ribbon of the Atlantic for spondents on board. But the speedy maiden voyage from Le not much has been writ- Havre to New York and back, is ten about the ship's ra- equipped with one of the most elaborate dio installation. marine radio layouts in the world with Much emphasis has been laid on the most interesting in any nation's mer- the call letters FNSK. In all of the luxurious interior of the liner. The elab- chant marine. newspaper and newsreel fanfare and orate staterooms, the palatial lounge, Radio -telegraph, radio- telephone ballyhoo, and accompanying the.liner's debut the roomy theatre, the imposing chapel radio navigation devices of many types in New York Harbor, little was noted -and many other features of the Nor - are included in the intricate Nor- regarding the, ship's radio apparatus. mandie's design -have been described mandie layout. Visiting the liner at And yet it was the Normandie's huge frequently. And in line with all the its New York pier, the radio installation writer was im- that kept the enthused grandeur of the ship's decorations and pressed with compactness of the equip- populace informed of the festivities equipment, the ship's radio layout ment. The radio room, large express - aboard the liner long before she steamed stands out prominently as one of the Liner size, is far from into Quarantine. the passenger hustle. A page boy guided the writer Broadcasts Widely Heard through narrow passageways and stair- SCENES BELOW DECKS ways to reach the radio room desig- From a crowded New York roof -top, The shielded radio equipment of the nated on the Normandie as the "com- the writer watched the Normandie's gal- monster vessel contains a wealth of mercial cabin," the term being used to lant and proud arrival. All neighboring the latest developments for simul- distinguish it from a special radio cabin roofs were also jammed with throngs taneous radio transmission and recep- reserved for the bridge to accommodate anxious to glimpse the newest addition tion services. Lower right: photograph radio equipment used in direct relation to the French Line fleet. This intense shows Gaston Magrin, famous to navigation. interest in the liner's debut was caused, chef, answering questions of An- to a large nouncer George Hicks, during a broad- extent, by the radio broadcast from mid -ocean Famed Radio Room casts over to America while the CBS and NBC chains Alfred H. Morton, NBC program The commercial radio cabin contains direct from the liner and the columns manager, right, looks on. an assortment of short -wave and long - wave telegraph transmitters and receivers designed for various marine frequencies. In addition radio- telephone transmission appa- (Turn to page 180)

www.americanradiohistory.com 142 RADIO NEWS FOR SEPTEMBER, 1935

A LIFE -SIZE PICTURE On the opposite page is shown a home scene where Peck's television receiver, operating in an illuminated room, pictures a television subject's head in full size with a sound accompaniment. The top photograph on this page shows the 6 -meter special television beam antenna which projected the pictures over a distance of over 70 miles.

tk,eporting Progress . . . . TELEVISION

TELEVISION has arrived in Can- on a screen with enough brilliance to be nal was increased to 75 miles easily. ada. It is not "still in the lab- readily visible in a normally -lighted To understand how Peck has more oratory"; it is not "just around room. It uses no costly cathode -ray than trebled the range formerly be- the corner" or the familiar "two or tubes; its only elements which need re- lieved possible for ultra -short waves, it three years off." It is actually on the placement are a $1.50 light -valve tube is necessary to know something of his air daily over the Peck Television Cor- and a 10 -cent automobile headlight background. Briefly, he is one of poration station, VE9AK, located in the bulb (the light source). Both of these America's foremost experts in the field Dominion Square Building, Montreal. elements give 5000 hours service. of optics, and sprang into international And Canadian radio manufacturers are VE9AK was erected in the middle of prominence during the World War, preparing to put a low -cost radio -and- May, 1935, as a 20 -watt station. It when he devised a means of making sex- television receiver on the market. then had a service radius of about ten tant mirrors that had hitherto been ob- Nor is it the "flickering" television miles. As the engineers under the per- tainable only from Germany. such as has been broadcast formerly in sonal direction of William ,Hoyt Peck, Phenomena Studied America; both transmitter and receiver president and chief engineer of the cor- differ greatly from apparatus which has poration, furthered their experiments, Knowing the familiar fact that ultra - heretofore been shown. The trans- the power was gradually increased to short waves are in many of their char- mitter uses an entirely gearless scanner 300 watts and the range for an R9 sig- acteristics similar to light waves, Mr. and with a 300 -watt antenna input is Peck brought his years of optical training to bear upon the problems which sending a strong signal more than DURING A FIELD TEST miles on the 5 to 6 meter they presented. He understood the re- seventy fin engineer and his assistants check- channel. Twenty miles had previously fraction of light by the earth's atmos- ing the strength of the new Canadian which enables us to see the been considered the practical limit for atop the phere, television transmitter, Do- -eight minutes after this 5 -6 meter television prior to Peck's minion Square Building in Montreal, sunset some twenty experiments. from a distant field. At right, the the sun has sunk below the horizon and The receiver, too, is different. It schematic diagram of Peck's television decided that the same phenomenon projects a 14 inch by 16 inch picture receiver. might hold for similar radio waves.

100 MMFD. 20,000 100,000 50,000 100,000 50,000 20,000 FILTER MICA. OHMS OHMS OHMS OHMS OHMS OHMS RFC. .25W .25W .25W .25.W .25 W .25 W 1 60 000 ;OHMS .2 a CORN MMOFD. , MIMOFD , ¡MMFD'/ MMFD.111 MFO. ,' M MICA, 954 MI 6D6 M A.;6D6 I A; 86

250 OOÓ' OHMS MFD -+T 250,000 _ OHMS 1 T .25W .n7:7STANDARD BROADCAST d ANTENNA 100,000 100 MMFD OHMS -MICA 12- 52 MEGACYCLE BAM D TURNS v; SPACING L2 , T0.O510 t ' OF 954 6 IO SOV. X < MMFD.. Id TAP AT 2 OR3 !0 TURNS FOR BEST 11111111 MFD. IMPEDANCE MATCH. NO-42 WIRE

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 143

71 MILES on 6 Meters

By Rupert in CANADA Oakille

Peck likewise, from long study of termined course, and to keep it from Joseph Dusek and other Peck light reflectors, developed a theory for engineers spreading. have conducted tests during directional antennas, which has worked The the past receiving antenna for these three months. Their figures show that out in practise. "If . you set up an waves is also an upright rod automobile and Peck signals of sufficient strength to over- headlight bulb with no re- has discovered that as little as five feet ride flector behind local interference are heard it," says he, in explaining difference in the placement of a receiv- throughout his theory, "it this entire territory. The will illuminate only a ing aerial which is seventy -five miles engineers have small area. But if you add established field head- a correctly from the transmitter may mean the quarters at' the Hotel Lafleur, designed reflector, the beam may be Louis- difference between an adequate signal ville, Quebec, where Roland Lefleur, projected a mile or more in a single di- and total lack of reception. He rection. ex- manager of the hotel, had been acting We are now applying this plains this by pointing out it is principle that as an unofficial observer, making nightly to the propagation of ultra - possible for a reflected wave, out of checks short radio waves." on the signal strength of phase with the direct wave, to cancel VE9AK. Later a complete receiving out, but that by moving the receiving installation was made here The Reflector Antenna antenna as a per- a quarter wavelength, the manent test station. The hotel, one of The output of the Peck Television phase shift problem is overcome. the largest in that part of Quebec, Corporation's was transmitter is fed into a Approximately 1,000,000 persons are thus the scene of Canada's first major single upright antenna -a small copper within the area in which J. L. Cassell, television demonstration. rod atop the Dominion Square Building. Nor is the Peck optical antenna sys- On three sides of this antenna are tem the only new development similar rods, of this tuned to the requisite fre- TELEVISION STATION VE9AK organization, which has steadfastly quency and placed /-wavelength away. adhered to mechanical These Looking into the control room of the scanning in pref- are the reflectors, each collecting Canadian television erence to the much -publicised the energy station VE94K, cathode radiated into its quadrant showing the short -wave transmitter, -ray equipment. "There is no and reflecting need to it back to the antenna the control panel, and at the extreme use more than 180 lines unless you proper. By want adjusting the length of the left, the pick -up apparatus. to watch television (Turn to page 186) reflector rods, their resonance and therefore their efficiency may be controlled, so that it is possible to tune them in such a way that signals can still be heard on the "dead" sides of the antenna as well as along the path of the beam. In this manner, it is possible for the one transmitter to serve two areas; i.e., the area immediately surrounding the transmitter (in this case the city of Montreal), and the area traversed by the beam, which at present lies between Montreal and the outskirts of Trois Rivieres, Quebec. At the side of the antenna from which the beam emanates, two upright metal rods are arranged. These, however, are placed in line at correct distances from the antenna and conse- quently act, not as reflectors, but as "electrical lenses," for their effect is to concentrate the beam along the prede-

www.americanradiohistory.com 144 RADIO NEWS FOR SEPTEMBERS 1935 New Features for UPER

John M.

band -spread ganged condenser. These items, together with a drilled chassis and a wiring harness constitute the THE COILS foundation kit from which this set may The r.f. and i.f. be constructed. All other parts __may_ .be coils are shown purchased independently -a distinct here with shields advantage from the standpoint of the cut away. R.f. coils experimenter who may already have with switch, trim- many of the miscellaneous parts on mers, and padders hand. . are assembled and wired by the manu- Continuous Band - Spread facturer. The receiver is a 4 -band, 8 -tube short -wave superheterodyne which has a continuous frequency range from 1.6 THE receiver described in this article than that, the r.f. coils are provided to 18 megacycles and is applicable to is an unusually suitable one for the with the coil switch and the necessary any type of short -wave reception, es- home constructor. With few exceptions, trimmers and padding condensers com- pecially short -wave broadcasting and it has heretofore been difficult for the pletely assembled and wired on a small "ham" activities. Continuous band home constructor to build up a modern subpanel. Thus, not only is accurate spreading is provided on all ranges by and highly satisfactory short -wave re- condenser, each the reason that it has been matching and alignment provided, but the ingenious tuning ceiver for of 140 difficult to purchase matched short -wave in addition, variations in wiring which section of which consists a coils adaptable to band switching. Even might seriously affect alignment of the mmfd. tuning condenser and a 33 mmfd. where such coils are available there has tuned circuits are avoided. In other trimmer, these trimmers being ganged been further difficulty in obtaining a sepa- words, all of the complications normally as shown in one of the accompanying rate ganged condenser suitable to operate found in assemblying an all -range illustrations. Rough tuning by means with these particular coils. short -wave receiver are avoided due to of a large gang is accomplished in the the cooperative effort of the General usual way, then the fine tuning or band ANY difficulties have been Manufacturing Company and the Re- spread is obtained by pulling out on the eliminated for the constructor liance Die and Stamping Company, two main knob. When in the "out" posi- M1 in the "Super DX -8" because manufacturers who worked together in tion, this knob operates the small con- all r.f. coils are carefully matched to the production of the tuning circuits. denser gang. Dials are available for work together and in turn the entire The former company manufactures use with this condenser and have two coil set is matched to the special band - the r.f., i.f. and beat oscillator coil as- indicating needles and two scales as spread ganged tuning condenser. More semblies, and the latter produces the shown in the photograph.

5W5 r 58 2A7 L43 58 L44 2A5 1 gr .C46

t27 C45 L4 B4 T R10 R16 C43 R19 ANT. R12 WJJVJJJ-- R13 FIGURE 4 R3 /1 5W3 R4 CRYSTAL CS C30 R2 2A7 L20 Li 2 R1 25 SW6 Cil 56 C26 C32 C33 C22 8+ CRYSTAL FILTER CIRCUIT C23 SW4

-C24 5W2 R22

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 145 the Home Constructor in the DX- 8 Borst

This band spread feature is a decided The intermediate - asset for all types of short -wave recep- frequency amplifier tion. In addition, the circuit included works on a fre- a beat frequency oscillator as an aid in quency of 507 kc. picking up weak stations or in c.w. re- The Gen -Ral trans- ception. For the use of the amateur, formers are of a there is a "stand -by" switch, by means new, highly efficient of which the plate supply is cut off but type; the coils the filaments left lighted so that the being wound in sev- THE COMPLETED ASSEMBLY receiver is made dead while he is trans- eral "pies" con- The single tuning knob controls regular tuning when in the "in" position. mitting. A quartz -crystal filter is pro- nected in series. To obtain band -spread tuning, this same knob is pulled forward, in vided for in the circuit and in the drilled This method which position it controls the band- of spread section of the main chassis for constructors who desire this winding has been condenser. feature. Both manual and automatic found to give the volume control are included; also a least resistance for a given inductance. The heterodyne oscillator, headphone- speaker switch. Finally, employing A duo -diode triode, the 2A6 serves as a 56 tube is coupled to the cathode complete drawings including the sche- second detector, of a.v.c. tube and resist- the i.f. amplifier tube by means of a matic circuit and picture wiring dia- ance coupled audio. A high -mu triode condenser. gram and a complete set of instructions is used, so as to obtain the most from The optional crystal filter circuit is for building the set are available with this hard -working tube. There follows shown in Figure 1 for the coils kit. the benefit of an audio stage, employing a 56 tube. constructors who desire this feature. When The Circuit Used listening on phones this is the The special chassis and panel com- last stage but when speaker operation bination is suitable for rack mounting The receiver includes one tuned r.f. is desired a turn of the switch will con- or for a metal cabinet. Holes, cutouts stage on all bands, a detector -oscillator, nect up the coupling to the last tube, and slots have been one provided for the i.f. stage, a second -detector a.v.c. the 2A5. It is not necessary to pull the mounting of the necessary parts. and audio tube, one straight audio phone plug out when switching from Looking at the front of the set stage and a pentode output tube. phone and to speaker. moving from left to (Turn to page 185) Figure 1 shows the circuit diagram of the receiver. The antenna terminals are arranged so as to accommodate TO PLATE COUPLING UNIT MORE IDEAS OF AUDIO TUBE 5 either a doublet or an ordinary L -type IN TUNER 59 MFD. 45'S antenna. The 58 r.f. tube is controlled ON by the a.v.c. along with the 2A7 de- and a 02 tector- oscillator and the 58 i.f. stage. 2 The maximum sensitivity of the re- MFD. ceiver can be adjusted so as to limit the interstation noise. When the a.v.c. is Power Pack cut out, the same sensitivity control is Ó used for manual adjustment. for the 15H 240 OHMS THE TUNING CONDENSER This unique condenser has dual sets VALENTINE of rotor plates operated by separate shafts. The band spread rotors are clearly shown. The main rotor plates "SUPERHET" FUSE 3 are visible on the opposite side. AST month the discussion covered the "Valentine" circuit up to the FIXED second detector. The present and concluding article covers the circuit briefly from this point on. -The Editor.

THE 56 second detector is used as a _ 20,000 OHMS diode ; plate and cathode being tied 4000 OHM(SPKR FIELD) together. Connection of the high end 2651 of the 3rd i.f. transformer secondary is made to the plate of the tube, and the return connected through a "pi" filter, consisting of an 85 mh. choke and two 2 16= 77,200 .00002 condensers, to one end of a 250,000 MFD. MFD. OHMS ohm potentiometer the other end of which goes to the grounded plate and cathode - .1 FI G.4 of the 56 diode. Between slider and cath- MFD. 1,A FD. (Turn to page 179)

www.americanradiohistory.com FOR SEPTEMBER, 1935 146 RADIO NEWS '`"ÿ 19 Tube ZECEIVER for High -Fidelity Reproduction Quiet Long- Distance Reception Sharp Tuning EVERYTHING UNDER FULL CONTROL! Figure 1. Wide flexibility of operation is provided by 9.4 to 2150 -Meter Range the 7 calibrated panel controls which are, left to right: High -fidelity, high -selectivity switch, audio volume, bass -note regulator, tuning (center), beat- frequency os- Silver cillator switch (lower center), treble regulator, band McMurdo switch, and sensitivity. The dial is accurately calibrated for all 5 ranges; with a "second hand" to facili- Above the dial is the to sound reproduction. tate logging short -wave stations. IT is the purpose of this article vacuum -tube voltmeter type tuning meter. briefly describe an all -wave receiver (f) Adequate whose designer has sought to derive audio - frequency for all regular and short -wave broad- maximum benefit from all available data range for high -fidelity reproduction, receiver fully variable to permit compensation for in- casting, police, airplanes and airports, in an effort to create a and even requirements that dividual home acoustics and reproduc- amateur, commercial 'phone, satisfying the rigid police signals. has indicated the fine tion at different volume levels. some ultra short-wave recent experience the 6.3 -volt type, meet. Among these re- (g) Adequate undistorted power out- Its 19 tubes, all of receiver must are: quirements are: put to satisfy (f) and to handle maxi- 2 in two r.f. stages (used on (a) Tuning range covering all broad- mum amplitude range of best present -6D6's and future broadcast transmissions. all bands) cast and other interesting services. first adequate for recep- (h) Simplicity and identification of 1 -6D6 as suppressor injected (b) Sensitivity detector tion of all signals not entirely obliter- all controls to provide flexibility essen- noise under any and all tial to satisfaction of all above require- 1 -76 oscillator ated by local as air -tuned, 465 kc. i.f. conditions. ments. 3 -6D6's (c) Inherent noise so low as to The MASTERPIECE IV receiver amplifiers consists of the tuner, a 35 -watt power 1 -6B7 as a.v.c. and tuning meter am- satisfy (b). rectifier (d) Frequency stability of an un- amplifier and bass and "tweeter" dy- plifier and 1 as audio beat oscillator usually high order. namic speakers. It tunes from 2150 to -76 1 as second detector and second Controllable selectivity permit- 732 meters (140 to 410 kc.) for airport -85 (e) tuning meter amplifier ting extremely sharp tuning or broad and European broadcasting, and from 1 as variably (Turn to page 188) tuning at will for full range high -fidelity 568 to 9.4 meters (530 to 32,000 kc.) -76

SHUNT COIL MFD. FIG. 3 4 365 MMFD. MFD. ALL I.F. TUNING CONDENSERS= 400 MMFD. 50,000 FIDELITY SWITCH - OHMS,, VOLUME CONTROL &ND.O , ANTENNA 6D6 6D6 , 6D6 6D6 E 1 85 76

6S MH. 05 ó ANT. L. .04 ÖNMS 0. .025 MFD. K' --4 5,000 MFD. 0Nss»> 3 ' ó MFD. OHMS 100 * MFD. - O MFD O 76 'MMFD OSC. 50,M00 ; OHMS OH05 I', "'5500 firdilfrmD 5 MFD ._ .MYa_ OHMS MFD. X X ' 50,000 55,00S0 ,250 MMFD OHMS OHM 400.000 250,000 2ND. R.F. OHMS OHMS STAGE .O5 MFO -- 0 MH. 1- CHASSIS. M OF TUNER PLUG BOTTOM 250 400 -SEN SITI V ITY MMFD. 351 OHMS OHMS TREBLE BASS loo 000 y FIELD FIELD OSCILLATOR .05 MEO. LL MFD. 16 MFD

T 4S. 5Z3 5Z3 MFD. XX: --_E OHMS 500 SOCKET OHMS BACK Ó01-IM i CHASSIS 320 POWER PACK OHMS 4 OF -4 MFD OHMS MFD. X MMFD:MMFD. MMFD.`MMFD

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 147

be appreciated from the fact that the 40- meter band, for instance (only 300 kc. wide), is spread out over 150 degrees on the main 6 -inch dial and requires 17 complete revolutions of the vernier tuning knob! Selectivity is attained by a sharply -tuned antenna circuit plus r.f. pre -selection and two triple- tuned, band -pass i.f. transformers, giving a total of eight tuned circuits. Separate audio volume and i.f. sensitivity controls are provided and delayed a.v.c. may be used, when desired. A phone -jack cuts the phones in on the first stage of audio but also includes the variable tone control (which is particularly useful as an audio filter on c.w. reception). A stand -by toggle switch turns "off" the high- frequency oscillator, but leaves the final diode detector and the audio amplifier in operation so that it can be used for monitoring if desired. The audio beat oscillator is coupled to one of the diode plates of the final detector instead of to the i.f. tube. This circuit arrangement gives exceedingly smooth c.w. signals and is very stable. The overall sensitivity of the set is better than one microvolt (absolute) on all bands, and this is usable sensitivity, the inherent noise level of the set itself being so low that very weak c.w. signals may be copied even on the loudspeaker. Glenn Browning's New In order to maintain a high usable sensitivity and keep the noise level at an absolute minimum, the loudspeaker has not been built into the receiver, but is furnished as a separate unit so that it can be placed where it will not introduce reaction RECLIVER noises under any conditions. The tuning dial is of unique design and should make a strong appeal to the expe- John Strong rienced amateur. Extra dials are furnished which can be quickly interchanged. The THE amateur communication receiver necessary in the usual all -wave job and electrical band -spread is so extreme that pictured here being tested in the allows true electrical bandspread, with one dial can be logged (directly in kilo- Westchester Listening Post is a 7 -tube high- inductance circuits used throughout. cycles), if desired, and used as a fre- superheterodyne designed by Glenn H. What this means in actual operation can quency meter. Browning for the sole purpose of serious amateur work. It incorporates the new Amateur Super -Tuner unit with r.f. pre - Making amplification on all bands. It is designed strictly for the 160 -, 80 -, 40- and 20 -meter amateur channels and will not receive the short -wave broadcasting stations. This has eliminated the compromises which are CQ KEY

CLOSE -UP OF THE DIAL from an old Here is pictured the new band -spread tuning dial for the 7 -tube amateur communications superheterodyne. The Windshield Wiper top calibration is for the 20 -meter band, including both c.w. and phone. The next calibration covers the 40- Ed. Glaser meter c.w. band. The third calibration covers the 75 -meter phone and AN automatic key was born ! A 6 -volt 80 -meter c.w. ranges and the fourth windshield wiper motor was pro- calibration covers the 160 -meter phone cured for $1.00 from an automobile and c.w. wrecking company. A pair of contacts was "lifted" from an old -time A.B. relay. A thin piece of phosphor bronze and a bakelite disc cut -out (for a meter) were advisable to add a pair of gears. A small found in the junk box. This key has been pinion of 12 teeth and a 1 -inch gear of a great help, saving a lot of time and 48 teeth gave a reduction of 4:1 which labor for amateur operation. Two discs turned out to be very satisfactory. The were made, one for "TEST" and the other desirable speed of the motor, of course, de- for "CQ." During early 5 -meter work in pends upon the size of the disc and what Brooklyn and, lately, for 75- centimeter characters are on the disc. For instance, work at Bellmore, the key has run for "TEST W5EE" on a disc would not require hours at a time. the extra gearing, as it could be run almost In the type of motor used the shaft three times as fast as the writer's "CQ CQ turns a worm which drives a worm gear. DE W2BRB" disc ! This, of course, with It is possible to put a disc right on this the same words -per- minute speed which is worm gear and this was done at first. all that matters in a key. So in all cases However, it was necessary to reduce the the gearing isn't needed. The condition of speed of the motor so much (using a series the motor is also an important factor. rheostat) that there was not sufficient The bearings on this particular motor were power to insure a stable arrangement. The not in the best of shape. motor ran unevenly over the cycle and The discs are of is bakelite and 2% occasionally stopped. So it was thought (Turn to page 183)

www.americanradiohistory.com 148 RADIO NEWS FOR SEPTEMBER, 1935 the 7-L1M "Shack ¡ A Department 1 for the amateur operator to help him keep up -to -date

Conducted by Everett M. Walker Editor for Amateur Activities

side -bands of at least 5 kilocycles on either side of the operating frequency. A properly operated c.w. station uses only one and is inherently- sharp. - When to the Federal A WELL -KNOWN BRITISHER frequency AMOVEMENT gain a modern receiving set is used with a crys- Communication Commission's sanc- Here is the transmitting apparatus of it is possible to obtain 200 -cycle Class A tal filter, tion of more frequencies for G5ZT, with its operator who has been selectivity. That means that more than telephone operation is well under way. heard in many countries outside of stations could operate simulta- an additional ten c.w. The proposal is to obtain the British Isles. - a 10- kilocycle range with- bands neously within fifty kilocycles in each of the two out causing an appreciable amount of allocated to Class A 'phone -75 and 20 interference to each other and a good oper- meters. The plan seems to have attained are completed 100 per cent. While an would not have any diffi- not solve ator probably the overwhelming support of the 'phone additional .50 kilocycles would culty picking out and copying any one of

. a men in this category. There have been the interference problem, it would go the ten. From a technical viewpoint there only murmurs of objections. long way toward helping the situation. to be need for a more columns certainly seems It has been pointed out in these equitable distribution of frequencies be- to gain additional band on a previous occasion that the number and c.w. THE plan the tween 'phone widths for amateur 'phone is for each of amateurs is steadily increasing, and favoring the proposal to popularity of telephone communication is Television Threatens the amateur On Jan- write the Commission, making the request. gaining at a tremendous pace. Amateur uary 1, 1929, when the present bands be- What is asked for does not involve the corn - effective, the total number . of li- The amateur has a threatening allocation of any new frequencies. It came visual censed stations in the United States was petitor in television. The art of merely requests an additional 50 kilocycles accomplished laboratory of the two bands where less than 18,000. Since then there has broadcasting is an for 'phone in each one of the largest research corn- - is permitted. The re- been only one change in allocation, with no fact, and Class A operation in the United States is spending for frequencies would follow the increase in frequencies. In 1932 the 85- panies quest then was 50 more than $1,000,000 in making a com- Dominion of Canada's recent sanction of meter 'phone band, which moved to the high - prehensive survey of the field from all an additional group of frequencies for tele- kilocycles wide, was frequency side of the 80 -meter band and angles (technical, commercial, etc.) and phone in the 20- and 75 -meter bands. The five 100 kilocycles were assigned to telephone will be prepared within at least years Canadian allocation, which went into effect service and receiving that frequencies be- operation. But the astounding thing is to offer a visual on April 1, provides number of li- equipment to the public. 3500 and 3550 kilocycles and 3850 that during this period the tween has increased to about The threat to the amateur is in the pos- and 4000 kilocycles on the 75 -meter band censed amateurs whereof it is estimated that more sible loss of his valuable ultra- short -wave may be used for both c.w. and 'phone. 60,000, was dis- ama- than 20 percent are licensed for Class A frequencies. The writer recently In the 20 -meter band the Canadian the possibilities of televisión with to use 'phone in their operation and an additional 25 percent are cussing teurs are permitted operation of some an engineer who should know what the entire band, which is 14,100 to 14,300 kilo- interested in 'phone Dur- kind. plans for the embryo industry are. cycles. course of conversation it was amateurs are requesting the There seems to be no logical reason why ing the American frequencies should brought out that the probable band of additional 50 kilocycles in the 75 -meter the additional 'phone allocated. Few of the "dyed -in- frequencies which will be sought for tele- band 3850 to 3900 to supplement the not be States the- wool" c.w. men have voiced an ob- vision broadcasting in the United present allocation of 3900 to 4000 kilo- 50,000 and 100,000 14,100 to jection to the proposal. In the 75 -meter are those between cycles, and in the 20 -meter band, and 100 megacycles). The to supplement the 14,150 band particularly, the portion of the band kilocycles (50 14,150 kilocycles are question was brought up about "other ser- kilocycles allocated for Class A in which the additional 50 kilocycles to 14,250 by c.w. vices" that now are assigned to these fre- operation. requested is not used extensively They congregate mostly around the quencies: what would happen to them Anyone who has listened in on the 75- men. and industry should last two low- frequency end of the band. True, if and when the public meter 'phone band during the for visual -broadcasting? It was not have failed to hear their interference problems would be helped be ready months should calmly but definitely indicated that only of the proposal. General to some degree if there was more of a ten- some mention one disposition could be made of the prob- be directed toward the dency to spread out, but their reason for criticism seems to was ` in accordance with carrying the operating on the low- frequency side is a lem, and that amateur organizations for not "public interest, convenience and neces- Washington, it being logically ar- logical one. Most amateurs, by habit, start fight to from the low fre- sity" -the prima facie rule governing the gued that the American amateurs should tuning their receivers authority. quencies to the high, with the result sta- decisions of the allocating have the same privileges as the Canadian amateur, of course, should not stand so in view of the tions on the low frequencies are the ones The operators, particularly in the way of the development of the tele- problem, which is certainly that are heard first and, therefore, seem interference But, - on the other hand, than in to have more QSO's. vision industry. more acute in the United States is no reason why he should lose any of the Canadian ama- On the two - Class A bands in which ad- there Canada. Furthermore, his present ultra -high frequencies, particu- be favorable to the United ditional frequencies are sought, the 'phone teurs would it . has been men have 200 kilocycles at present against larly in view of the fact that. States opening up the additional channels who has developed their is successfully 700 kilocycles allocated to c.w. That is a the amateur operation. It - for 'phone favoring practicability! Television, as it is being argued that the amateur channels should ratio of 22 percent to 78 percent that might be pointed developed now, requires a tremendous band be uniformly allocated throughout the c.w. Another thing one out in favor of the need for additional of frequencies for the transmission of North American continent. and -sound program. "A band frequencies for 'phone frequencies is the width of the single sight- The need for additional 1500 kilocycles is required for the trans- is indeed channel required for a modulated signal t of telephone operation apparent. mission of a single program. In other is extremely severe on these against a continuous wave signal. One Interference peak words three television signals could not two bands and it is seldom that contacts hundred percent modulation produces

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 149 be transmitted simultaneously in a given area at the same time in the amateur's 5- meter band (56,000 to 60,000 kilocycles) ! While television is still in the future, when it comes it will come quickly. It is bound to. In its present laboratory status it is "pretty good." Highly entertaining pictures may be had right now. When it comes in commerciallly, it will be offered as a service supplementary to aural broadcasting-which its planners hope it will not supplant! It will be offered only two to four hours daily and, at first, only in the larger cities. But the point is that plans for its development are being made quietly "behind the scenes" and it has been decided that 50 to 100 megacycles is the logical television band. No allocation has been made nor it likely to be made within the next year and a half, but it is being thought about! Therefore it is time for the amateur to think about it, too, and to prepare to keep the ultra -high frequencies he now has! (Turn to page 179) JACK TARS OF THE FUTURE Boys at the Bernardo Naval School at A Pioneer CSCG Member Norfolk, preparing for future radio service in the Navy. RICHARD D. WATSON, owner and operator of W1BGL, 6:00 P. E. W8EEZ 3598 Dover, H. Dick's station RADIO NEWS Sponsors New 6:30 P. C. W9LKK 3757 N. was 7:00 P. E. W2HCP 3753-3835.5 one of the first CSCG practice sta- Opportunity for Code 7:00 P. E. W3AEJ 3785 tions. When he was at the key, Practice at Home 7:00 P. C. W9SFT 3585 before leaving with the Byrd Ex- 7:00 P. M. W9HHW 7276 RADIO NEWS takes pleasure in publish- 8:00 P. M. W7DBP 3722 pedition for Little America, his 8:30 P. E. W8FQS 3582 "fist" was known far and wide. ing the following schedule of code trans- "Spud" Henderson, radio opera- missions in the United States especially for THURSDAY tor, KFS, the Mackay radio station those who wish to learn the code over the 8:15 A. E. VE3UU 3865 air. All one has to do is to tune in to the 9:00 A. E. W2 HZJ 3577 at Half Moon Bay, California, who 3:30 P. C. W9TE 7012 handled the Byrd traffic with proper frequency as specified at .the proper 6:00 P. E. W8MHE 3610 Dick, time said Watson was one of the finest and day and start copying the special 6:00 P. E. W8EEZ 3598 code transmissions for practice. A daily 6:30 P. C. W9LKK 3757 operators he ever worked with. 8:00 P. M. W7DBP 3607 Dick says: schedule is given for the present month 9:00 P. E. W8FQS 3582 (beginning Aug. 1st and ending "I am mighty glad to know Sept. that 1st). In the first column is the time (a.m. FRIDAY RADIO NEWS is publishing CSCG or p.m.) ; in the second column are the 9:00 A. E. W3AEJ 3785 schedules each month. This is a 9:00 A. ED. W2HZJ 3577 great thing for symbols, E, C, M and P (where E. is used 3:30 P. C. W9TE 7012 all who really want for E.S.T., for 5:00 P. P. to improve C C.S.T., M for M.S.T. W7WE 3637-7274 their handling of code. and P for P.S.T.). In column 6:00 P. E. W8MHE 3610 the third 6:00 P. E. W8EEZ Not only do CSCG activities tend are the call letters of the transmitters 3598 to improve Amateur Communica- of 6:00 P. E. N1DUZ 3638 tions, amateur members of the Guild and the 6:30 P. C. W9LKK 3757 as it already has, to my fourth column contains the frequencies 7:00 P. E. W2HCP 3753-3835.5 of 9:30 P. E. W4BHR knowledge, but it will encourage transmission in all cases, except where 3867 serious -minded fellows to push on otherwise noted. Each CSCG transmitting SATURDAY toward their goal by making the station will begin his program at stated 8:15 A. E. VE3UU 3865 right kind of systematic practice time by sending "CSG" 6 times, followed 8:30 A. E. W1AMH 56,100-3536M available every 9:00 A. ED. W2HZJ 3577 hour of the day. by his station call repeated 3 times, slowly. I shall be back the 6:00 P. E. W8MHE 3610 on air with At intervals of 5 minutes, he will repeat 11:50P. P. W7WE 3637-7274 CSCG programs just as soon as I "CSG" 6 times and his call letters 3 times. SUNDAY rebuild my station." All who listen to CSCG programs are re- RICHARD D. WATSON, 8:15 A. E. VE3UU 3865 73- W1BGL. quested to write a card to the transmitting 9:00 A. ED. W2HZJ 3577 station telling him how his signals come in 10:30 A. E. W3EEY 3628 and, if possible, sending him copies 10:30 A. C. W5DDC 7200 of 11:00 A. E. W8KGM 3807 transmissions. 1:00 P. P. W7WE 3637-7274 6:00 P. E. W8MHE 3610 MONDAY 7:00 P. C. W9LUS 3631 8:30 A. E. W1AMH 56,100-3536M 8:00 P. M. W7DBP 3722 9:00 A. ED. W2HZJ 3577 9:00 A. E. W3AEJ 3785 4:00 P. E. NiFNM 3510 Active Members 5:00 P. P. W7WE 3637-7274 Candler System Code Guild 6:00. P. E. NI DUZ 3638 6:00 P. E. W8MHE 3610 W1AMH- Harold J. Morse, 48 Hebron St., 6:00 P. E. W8EEZ 3598 Hartford, Conn. 6:30 P. C. W9LKK 3757 N1DUZ -J. E. Vermeiren, 137 Middlesex St., 7:00 P. E. W2HCP 3753-3835.5 Springfield, Mass. 7:00 P. C. W9SFT 3585 N1FNM -G. W. Wabrek, New Hartford, Conn. TUESDAY W2HCP -A. P. Bloser, 82 Dove St., Albany, New York. 8:15 A. E. VE3UU 3865 W2HZJ- Walter G. Germann, 9q5 E. 169th 9:00 A. ED. W2HZJ 3577 St., New York, N. Y. 3:30 P. C. W9TE ' 7012 W3EEY H. A. D. Baer, BAER 4:00 P. E. N1FNM 3510 -Dr. HOS- 6:00 P. E. PITAL, Allentown, Penna. W8MHE 3610 W3AEJ -Geo. W. Knowles, 82 Elgin Avenue, 6:00 P. E. W8EEZ 3598 Westmont, N. J. 6:30 P. C. W9LKK 3757 7:00 P. M. W9HHW 7276 VE3UU-Gordon Murray, 53 Elm Grove 8:00 P. C. W5CPV 7149 Ave., Toronto, Ont., Canada. 8:00 P. M. W7DBP 3607 W4BHR -James W Randolph, Warren Plains, 8:30 P. E. W8FQS N. C. 3582 W5.DDC- Herbert Leo, 1420 Hawthorne St., Houston, Texas. WEDNESDAY W5CPV-Grady L. Hardin, 132 Oak St., Hot 6.00 A. C. W5DDC 7200 Springs, Ark. 9:00 A. E. W2HZJ 3577 W7WE-Loren C. Maybee, 3516 Hudson St., 3:30 P. C. W9TE - 7012 Seattle, Washington. 4:00 P. E. NIFNM 3510 W7DBP -F. W. Stuart, R. F. D. 2-Boise, 5:00 P. P. W7WE 3637-7274 Idaho. 6:00 P. E. W8MHE 3610 (Turn to page 179)

www.americanradiohistory.com 150 RADIO NEWS FOR SEPTEMBER, 1935 More Than 1,000,000 Miles Grassing in Less Than a Week Continents and Oceans HROwith the National Amateur Communication Receiver)

L. M. Cockaday

IF one listens in on the amateur tele- a story of the results, whatever they AT THE WESTCHESTER phone bands for any length of time, might be, for the growing list of ama- LISTENING POST is a lot of talk of in- there heard quite teur radio enthusiasts and short -wave The author, with his assistant, Wm. C. terference breaking up QSO's. After listeners reading RADIO NEWS. the receiver through its for a week at Dorf, putting using an HRO receiver Accordingly, one of the rack -and- paces on high- frequency bands. the Westchester Listening Post, it is our the opinion that many of the amateurs really have quite excellent transmitters, but panel mounted jobs was obtained and that some of the receiving apparatus may FOR "REAL" BAND- SPREADING was set up as shown in the photograph be quite mediocre or even "haywire" Pictured here is the plug -in coil at the Listening Post and immediately regarding selectivity, frequency stability with the finger pointing most from image frequency arrangement, there started (for me) one of the and freedom at the screw which is shifted to the troubles or cross modulation. enjoyable DX tours of the world that next hole, to make the unit "band - it has been my pleasure to make -via spread." There is a screw for each short waves. During a week of recep- THE term "HRO" in connection one of the four coils that should be with an amateur communication tion running from 10 meters up to the shifted. On the 20 -meter band this from receiver has been rolling off the gave a running dial -length of inches ' standard broadcast band, signals tongues of amateurs, now, for some to each phone station. the most difficult stations to tune in months. It's become some- were received with a mini- what of a mystery. The mum of background noise receivers in question have and with a freedom from been very scarce and hard interference and "swing- to -get and most of the dope ing" that we believe to be on what this receiver actu- at the very peak, par excel- ally can do has been hear- lence, that radio engineer- say and rumor. Your ing and fine workmanship editor decided that he would permit. would make an effort to get But first let us describe one of the receivers, test it shortly what the receiver out in his DX Corner at is. It is a single-signal the Westchester DX Lis- type receiver with a really tening Post and then write usable (Turn to page 186)

0005 2B7 -6B7 PHONES .4 MFD- MAIM 57oR 580R SBOR .00025 2AS OR 58 OR 58w1 MFD- MFD.\ 42 6 D6 6D6 6C6 .ID 6D6 6D6 1

PHASwO w MEG'"_._

MEG. u¡w- J1 Ir , 5 .01 5000 MI OHMS OHMS OHIS MEG. I MFD MFO. MFD. 10 MFD. . ceFn.v. SPEAKER FD. , 57 6C6 50,000- 57 20.000 .1 20,000 OHMS OHMS- OHMS 6C6R OHMS .25 MEG. NMMN MFD. 1_ 3OHMS0.000 MFD. 2t St 00 4000 /T FD. ÓHMB 111 OHMS 10.000 100 000 OHMS 111`11N4 OHMS R.F. GAIN `4 1 MEO. a- FD. MEG. O 6t Ç- 0000 C.w. O5C. :/. OHMS 1 MFD.

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 151 Theory and Practice for Correct

IMPEDANCE MATCH j2=-1 C. A. Johnson J3=-NET Part Two

THAT the impedance of a circuit make the current lag behind the e.m.f. element consists of some equiva- by 90 °. (3) Capacity tends to make lent resistance in ohms plus a the current lead the e.m.f. by 90 °. phase angle, we learned in the preced- allel circuits and complex networks we ing article. We showed that the net Simplifying the Mathematics proceed as follows: impedance of two or more circuit ele- Impedance 1. Draw the part of the circuit under ments in series could be determined calculations for parallel and divided circuits are simplified we consideration. either graphically or by means of a for- if have some 2. Write the expression for the im- mula. In either case, the final result way of designating this phase- changing property when writing pedance of each of the elements was a value for Z in the following gen- in terms of formula (1). eral form: the equations for the circuit. The small letter "j" is usually used for this pur- 3. Combine these expressions as Z [some ; = value in ohms] [some pose. If the impedance under consid- much as possible, using the ordi- phase angle] eration is purely inductive, we set a nary rules for adding series and In general, this value was different for +5 in front of it. If it is purely ca- parallel resistances. different frequencies. pacitative, we set - j in front of it. 4. Using the ordinary rules of al- These facts are of fundamental im- If the impedance is purely resistive it gebra, separate the reactive parts portance and the reader should master has no prefix. Any impedance can be from the resistive parts. Remem- them if he is seriously interested in un- completely expressed by dividing it into ber that anything preceded by a derstanding problems of impedance. In its resistive and reactive parts. There- j is reactive. this installment we want to show how fore, the general expression for an im- 5. From step 4, you will obtain an the impedance of more complicated pedance may be written expression of the same form as branched networks is determined. It formula (1). Substitute the nu- may not be necessary for you to become Z =R ±jX (1) merical values of the problem into skilled in the details of impedance cal- When this expression. Using formulas culations, but you will be handicapped R = resistive part in ohms (2) and (3), you can solve for in any work with electrical circuits if X = reactive part in ohms the value of the impedance in you do not have a general idea of how ± j = an indicator telling us (1) that ohms, and for the phase angle. it is done. The procèss may appear to X is reactive, and (2) whether Before illustrating this process we be a little involved; but bear in mind the net value of X is inductive need to explain a little more about the that we are dealing with a very in- or capacitative, depending upon mathematical nature of our phase indi- volved problem in electrical and radio the sign. cator j. Textbooks frequently refer to engineering. This type of formula is called the it as the "operator j." This merely Let us return, for the moment, to our "complex" expression for an impedance. means that it doesn't have quite the problem of the choke coil having a re- To illustrate the use of this notation same function as the ordinary letter sistance of 3000 ohms and an inductance we will write the impedance of the ele- symbols used in algebra. However, we of 1 henry. We found that its imped- ments discussed above in complex form. can multiply and divide j into itself. ance was For the 1 -henry choke coil at 100 For this purpose it may be considered Z = 7000 ohms 164°.5 cycles: to have the value of -\/- 1. This means that when a 1000 -cycle Z = 3000 + j 6280 ohms Thus we may tabulate the following e.m.f. is applied to values of the power of j. the coil, there are For the 1 -henry choke coil in series j =V/ _ -V-1; two factors influencing the phase of the with .05 mfd. at 1000 cycles: -1; i3 resultant current. The resistance part j2 = -1; r = -f 1; etc. of the coil tends to keep the current in Z = 3000 + j 3080 ohms What "j" Means phase with the e.m.f., or along the For a 1 mfd. condenser in series with horizontal axis on the vector diagram. 500 ohms at 1000 cycles: The meaning of these successive powers of j becomes clear if we look The reactive part of the coil tends to Z = 500 j 159 ohms cause the - at the four quadrants of the vector dia- current to lag 90° behind the Now if we keep in mind e.m.f., or to make the mean- gram in Figure 1. Successive opera- it coincide with ing of j and j, it is easy to evaluate the vertical axis. The - tions of j upon a vector quantity (such result, of course, these or any other expressions in is that the current vector terms as current), rotates the vector in a takes an inter- of ohms and phase angles. The final mediate position 64 °.5 counter -clockwise direction in steps of from the hori- value of the impedance, Z, in zontal axis. ohms, is 90 °. Note that when j is on the hori- the vector sum of these two parts. The Now let us insert a .05 mfd. con- zontal axis it (Turn to page 155) tangent cp, denser in of the phase angle, is always series with the coil. This in- given by the reactive troduces a third force part of the ex- which tends to pression divided by the resistive part. -Zb----- make the current lead the e.m.f. by °. í 90 The sign of the phase iyI e1 As a result angle is given by the current vector will ro- the sign j. RL tate in this direction, of This information may be but will come to condensed into following rest at a point the formulas, about 45 °.5 above the where the terms vertical axis. The impedance have the same mean- is also ing as in formula (1): reduced to 4250 ohms. Thus we see that each of the different kinds of ele- Z = ß/R2 X2 ohms (2) ments in a circuit produces one of three X effects on the current. (1) Resistance tan¢ = - (3) tends to keep the current in phase with R FI G. 2 the e.m.f. (2) Inductance tends to In solving for the impedance of par-

www.americanradiohistory.com 152 RADIO NEWS FOR SEPTEMBER, 1935 f itrle BRAINWORK make Profits for Barron

the Elks and let it hundred dollars for such equipment. go at that. What In the small town where I live, the about the music local moving -picture house used to send teachers? But what a truck with a 5 -piece band running in the world can a about town, advertising its new bills. music teacher do They could not afford it any more, so with a public - the local radio doctor got on the job address system? and sold the management the idea of Nothing, to be a radio -equipped truck, playing phono- sure. But they can graph records. He used a standard do a great deal with P. A. outfit with a turn -table slung from a P. A. system pro- springs so that road bumps would not vided with a re- affect reproduction. This fellow netted $200 in these IT may be said with very little fear of cording head. Imagine, if you will, a $200 on the job. Now contradiction that the opportunities music teacher set up with a small but days, divided by four, leaves a weekly for money- making in the radio industry good recording outfit. The business ad- income for a period of one month of today are just about double what they vantages that they enjoy over their $50. Not bad for such times from one were four or five years ago. This may competitors is simply tremendous! sideline. sound very much like an overstatement Willie is taking violin lessons. of the pro- Little to the more cynical members The teacher records his playing, advises Group Hearing Aids fession. It is nevertheless an incon- moving picture theaters have clos- him to take the record (which may cost Some trovertible fact that will bear the on a group of est examination. a dime) home and play it on his phono- installed head 'phones graph. He listens to his own mistakes. seats so that hard -of- hearing people to the talkies. Since such IT is my opinion that many radio men But what about mother and father? may listen have suffered unduly from the de- They naturally get all puffed up over jobs may now be handled by service- other folk) merely little Willie's phonographic début. The men, they offer a profitable field in pression (like many Then take the case they do not look for business same holds true of any instrument, but small communities. because - The first ten rows in the right places! In the right places it is in voice -culture that this system of the large church. whole prob- has greatest advantages and proves its of pews are usually rented. Many -that is the secret to the not are too bound to the old real worth. Foreign language schools people who are hard of hearing do lem. They they cannot hear channels of trade, repairing, selling new can, and do, use the same kind of equip- go to church because with sporadic business in tube re- ment for precisely the same purpose. the sermon or take part in the service. sets, and if the placements. This is admittedly pretty Any minister knows this, Profits he is convinced that dull stuff these days, and if a fellow This Idea Brought church is wealthy is needed. In a case can make a living at it he must hump L: know of a radio serviceman in a such equipment and hump fast. city of 500,000 who made six such in- that recently came to my attention, the has been written about the pos- stallations within three months at a minister was partial to the idea, but he Much to spend. The of the P. A. field and some very tidy profit. After he had placed did not have the funds sibilities He knew nice business has been had from this the equipment in two music studios, radioman was a live wire. subscribed to the source by the more alert and business- business began coming to those places that the people who like members of the clan. They have, at such a rapid pace that competitors pews were "the" people of the town and held sales efforts to too of these studios simply had to fall in he immediately set out to get their however, their tell them an application of the P. A. field. line and have the same sort of equip- help. He simply wanted to limited who could They canvass the local Masonic lodge, ment. It is not difficult to get three that there were many people

PUNCH TOP PRESS FIG. 4 VIEW PHOTO OF CELL TRUCK LIGHT PHOTO SOURCE CELL TO LIGHT RELAY SOURCE AND BELL .. :,,. ....; dI1 :.: :::;,w .; =ti:t::<' . ;<:::..::::...... r.,.K;..:.::_:::.. BUILDING .:.,`..;::;:.:.;;:`'t BUILDING Fl G.2 LOADING PLATFORM

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 153 and

l Servicemen R. Mace not hear because they had to sit too first fellow he ran far back and he wanted help so that into knew nothing everybody could hear. He did not have about photo- cells, to go far. The first man he told about never heard of them it agreed to bear the cost of the whole as a matter of fact. two - only thing himself ! And we still solicit He said the BY LITTLE WILLIE problem he had A RECORD dollar repair jobs!!! that teacher of his students' States have at that time was Such records made by a music Most cities in the United his business-and the sale and installa- brokers are not "those `blankety- progress helped brokerage offices. And tion of the recording equipment brought profits to one entirely "broke." The job that I am blank' truck drivers progressive serviceman. about to mention came unsolicited, but that delivered ma- gave a radioman an idea that has terials to the store- it radioman was a grade -A since netted him a fine profit. Indeed house." He had finished paying a six - in fun, but the for the last three hundred- dollar repair bill caused by salesman; on his toes every minute. An it has kept him busy told broker's office there careless drivers who backed into his idea flashed through his mind. He months. In every stop Jones news ticker over which building with such force that they did his to -be- customer that he could is a Dow, for (Turn to page 186) comes all sorts of financial news of real a great deal of damage. This was told that damage importance to traders. However, if a trader is watching the ticker, he often misses many important things that come over the Dow, Jones system. This is every broker's problem and this particular broker got the brilliant idea of installing a P. A. system and having a clerk read the news off to the traders. This would not interrupt trading and the traders would appreciate the service. It worked like a charm. Other brokers in the same town were approached and sold. Some came and wanted the system installed merely because they suddenly realized that they needed it and they wanted to meet competition. The fellow in question, after he had sold all of the brokers in this town that could be sold, hopped in his car, drove sixty miles to another city of 300,000 and sold seven more systems. And they still sell vacuum tubes!!! strate the operation of a home receiving Photo -Electric Opportunities "Seeing" set to thousands of studio visitors each Much has been said about photo- day. electric installations and some radiomen Built on a scale of 20 to 1, the set have entered this phase of the elec- has mammoth tubes. When the guide tronic field. Many of those who have RADIO speaks into a microphone or plays a tried it have not had the proper busi- phonograph record, the sound is con- ness slant. verted into radio energy, then con- along a Jump in your car some morning when ducted to the array of tubes SIGNALS line which indicates the antenna lead. business is slow and run around to see manufacturers, who may Another line denotes the electric current. the smaller arranged want to cut down expenses. Of course, Cathode- oscillograph tubes, Samuel Kaufman of the model, show 90 per cent of these factory men never in cut -out portions cell and some the course of the sound energy through heard of a photo -electric and have to be done, but the AHUGE model of a radio receiver the various stages of conversion talking will lines indi- talking can in many cases be made was erected recently by NBC and amplification, and by wavy profitable. RCA -Victor engineers in the net- cate what the currents of electricity One radioman did this trick and the work's Radio City studios to demon- (carrying this energy) look like.

www.americanradiohistory.com 154 RADIO NEWS FOR SEPTEMBER, 1935

aerviCernere's This Month's Prize Winners ! FIRST PRIZE -To C. F. Henry, Henry's Radio Service, 104 Mel- rose Drive, Syracuse, N. Y.-$10.00 PRIZE CONTEST for practicability. An idea that every serviceman can put into immediate operation, with the prob- QAnnouncement of eAwards ability of realizing quick and consistent profits, the building up of customer good will, with added re- Zeh Bouck spect for his servicing ability and Service Editor versatility ! SECOND PRIZE-To Anthony S. Yeouze, 32 Mulberry Street, FIRST PRIZE FOURTH PRIZE Buffalo, N. Y. -$5.00 for an en- Kit of Electrical Parts Using a Mike to couraging word to beginners in the A Spare Clinch Sales service business! "I thought of a little scheme a few "I thought I knew all the tricks in the THIRD PRIZE -To Roger H. months ago, which, with a modest invest- retail radio game, but I learned something Hertel, Hertel's Radio Store, Clay ment, has put quite a few extra dollars new from a friend of mine who is also in Center, Nebr. -$5.00 for an idea in the service till. I invested about $15.00 the service business. I noticed that he had that recognizes the psychological in an assortment of plug fuses, 2 -way quite a few microphones around the shop, fact that some folks are too lazy sockets, rubber and bakelite handle caps, and I jokingly asked him if he was build- to stamp an envelope, write a let- parallel lamp -cord wire, asbestos -covered ing a broadcasting station. Not on your ter or telephone! heater cord, duplex outlet boxes and plates, life,' was his reply. `These microphones FOURTH PRIZE -To Harry key and chain sockets, flat -iron heater are my sale clinchers. Haven't you ever D. Hooton, Radio Service Co., plugs, etc. I carry this collection in an seen a man grab up a mike when a public - Beech Hill, West Va.-$5.00 for otherwise discarded analyzer case. Either address system was being set up? Folks novelty! when I have finished a radio job, or dur- are just crazy to talk into a microphone. ing the process (if repairs are made on the Here's how I work it. When I'm demon-. FIFTH PRIZE -To Harry spot) I bring up the subject of radio strating a new set, I first put it through its Schmidt, Radio Service, 117 -03 noises. It is usually possible to demon- paces; then I hook up the mike and let Hillside Avenue, Richmond Hill, strate what defective equipment will do. the customer talk into it. The effective- L. I., N. Y. -$5.00 for the time and I tactfully suggest replacement at a ness of this little bit of sales psychology tested and always reliable blotter nominal cost. There are few homes in is surprising to say the least. There isn't reminder, with a genuinely useful which some piece of electrical equipment anyone who is immune to the thrill of imprint! - has not gone haywire, and odd jobs almost handling and speaking into a microphone Congratulations and thanks - invariably result. I make no labor charges for the first time. I've sold several sets from RADIO NEWS and its service- for this work, but get a fair price for the that would still be in the shop if I hadn't men readers! parts. This makes the selling job that much easier, using the argument that calling in an electrician would cost consider- WHEN YOU REQUIRE ably more. For the average serviceman, I RADIO SERVICE FIFTH PRIZE believe this scheme will be well -worth the CALL slight extra time involved -both in profit A Blotter Reminder That and good will." VI. 7 - 7891 Is Useful KC. STATION DX STATIONS 570 WMCA Station Dial No. Location "I find the blotter shown in Figure 4 of Na0 WEAF real utility in building up and maintaining SECOND PRIZE 710 WOR my radio service business. It is a first 760 Wz Gets Ahead 8t0 WNTC class blotter that survives this particular A Newcomer 860 WABC usefulness in that the back contains a sta- 940 WAAT "I am a new -comer in the radio serv- Icio WHN tion log -for locals and DX-and a kc.- ice business, having started January of this 1140 WLWL meter conversion table." 1180 WINS year. I have made what I consider a 1250 WHEW 1300 WEVD success in the face of considerable competi- OUR RADIO NEEDS ATTENTION. Please call and 1350 WBNX We have a tion. My nearest competitor is only a few 1400 WBBC service this radio as soon as possible. blocks away, and has been in business over 1450 WHOM Model No. 1500 WWRL It is a battery net O. All electric net four years. I attribute my success to the To Convert Meters To Kilocycles D 6 -inch by 9 -inch cards (Figure 1) which 300.000 41500 KC = 200 Mean Brief description of trouble 300,000 =200 M = i CO KC. I had printed. I distributed about fifty 1 Megacycle = 1,000000 Cycle = I000 Kilocycles of these among nearby stores, garages and IO MC = 10,000 KC. = 30 Maas filling stations, the proprietors of which RADIO SERVICE Other electrical appliances needing service' were almost invariably happy to co- HARRY SCHMIDT operate. The garages and filling stations 117.05 HltlsideAze. Richmond Hill, Mr. or Mrs . Address receive a 15 per cent commission on all work they direct to me. The other stores FIGURE 4 FIGURE 3 ABOVE I endeavor to repay with my patronage." FIGURE 2 BELOW Mr. Yeouze looks at us from Figure 2. used the mike as a sales clincher. Some of you fellows might try it on those hard - boiled customers you have been trying to THIRD PRIZE sell for so long!'" Card That Brings in Business A FIGURE 1 "Recently we spent about three months in a countrywide, radio -set inspection. We called on every home and (where permit -. Prompt Guaranteed Service On All Makes ted) checked the radio installation free of charge. .In many instances this resulted in YEOUZE RADIO SERVICE immediate service jobs. In all cases the Phone Cleveland 6216 card shown in Figure 3 was distributed. This card is self -addressed -of the `business reply' type requires no stamp. The -and Mulberry St. Buffalo, N.Y. wording is self -explanatory. We have re- 32 ceived many cards back-with more coming- in every day. The same card is given to any customer bringing his set into the POSE Address Sound Systems Rented For All Occasions shop."

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 155

Cjei- This ei[utomatic TIME SWITCH Increase Your Revenue John H. Potts

(TOMATIC control devices have ap- Oil burners may be turned on before peal, fascination and utility in the arising, warming the room after a freezing home, just as they do in other loca- night. In homes using other heating sys- tions. The simple, self -timing switch pic- tems, a small electric heater may be turned tured here fills a great number of needs. on to accomplish the same result. In hot Prowlers are tempted by darkened homes. weather, the bedroom fan may be kept When away, the automatic switch can turn in service until one falls asleep, and may on lights during the evening, so that the be shut off at a pre- determined time. With family's absence is not advertised. The the switch, the radio may play until mid- INSTALLED ON A RECEIVER switch will shut off the lights when not night and then shut itself off or awaken us Mere is the time switch connected to needed, thus giving economical protection to music at the required time in the morn- a receiver and set to turn it "on" for when visiting or away on vacation. ing. If we desire not to miss a special a specified program and to turn the The device consists essentially of an a.c. feature, the clock may be set to turn on receiver "off" when the program is operated electric clock with independent the radio at the specified time and turn it ended. circuit -opening and closing switches. It off when the program has ended -of par- may be adjusted to give automatic switch- ticular advantage when extension speakers FSNANCIAL success in radio servicing "on- and -off" of any light or appliance are used. Defrosting the refrigerator may ing is largely a matter of technical within its capacity at any interval from also be taken care of. ability plus salesmanship. Increased 45 minutes to over 23 hours -and to re- Merchants will welcome the economy profits and excellent advertising result peat the operation- day -in and day -out- which the device makes possible in the from the sale of good side - lines. for an indefinite period. operation of small signs and window dis- plays. These may be automatically shut off late in the evening when their advertising value is a minimum. Schools may Selling This proved very successful. People use the switch to operate time bells at whose radios did not seem to be working specified intervals, without individual at- as well as formerly took advantage of it, tention. and, of course, Mr. Woodward made the Many additional applications will sug- inspection when they called up. Almost gest themselves. The automatic switch will SERVICE without exception a free inspection sold who specializes in its bring the serviceman new tubes or brought in a repair job so installation extra profits and increased in that his trip was not wasted. "Anyhow I prestige. the have plenty of time at my disposal," he explained, "and this was one good way of getting business or leads to jobs, and of SMALL TOWN getting acquainted with set owners. Fred E. Kunkel Classified Ads Pull Impedance Match (Continued from page 151) to business for ten miles He also uses the classified columns of a "TOW get newspaper, advertising his 1.1 around -how to get business in county radio becomes an ordinary number. From this home town? These and other repairing. "I thought I'd try it," he ex- it follows that any coefficients of even your own plained, "and I got a call the first day questions are happily solved by Craig powers of j represent a resistive part of the the `ad' appeared. It is very profitable Woodward of Flash Radio Service in impedance. It may be positive or nega- Md., who devotes his en- advertising, since country people read tive, and the sign must be taken into Gaithersburg, everything that appears in a newspaper, and a to radio ex- account in its addition. When j is on the tire time small store including the classified `ads.' clusively -sales and service. vertical axis, it contains V- 1 and belongs "Being run at a low cost and always to the reactive part of the impedance. In WITH very low rent and a low elec- producing results, I keep it in every week. mathematics, the quantities along the hori- tric light bill, the telephone is the We get a lot of road work out in the zontal axis are sometimes called "real" only expensive item of overhead he country, ten and fifteen miles away. A quantities to distinguish them from the has, and his advertising which is very ef- radio expert in a small town is something coefficients of 1, which mathemati- is also inexpensive. V- fective like a doctor. He gets his business every- cally speaking, are "imaginary" quantities. Among the many ideas used to keep in where, out on the farms and in the small contact with radio users is a little card towns." Now, to illustrate the use of the operator j, we will derive a general formula for the which he persuaded the local newsboys to Another thing about Woodward is his deliver with their daily papers from door impedance between the terminals 1 and 2 systematic way of doing things and keep- of the circuit in Figure 2. The purpose of to door for a small consideration. Card is ing his store in first class shape. While reproduced herewith. this calculation is to illustrate a general working on a set he takes out the parts application of this method, so that it will such as knobs, bolts, washers, etc., and mean something to you when you en- puts them all in a drawer at one place counter it in other literature. so he has everything together when the outlined above, is back together again. Throwing Following the procedure set put for each FREE FREE the parts all over the bench and then we will first write the impedances spending an hour looking for some missing element using complex notation where required. Inspection of Your Radio part, cured him early in his experience, so now he has everything right at his finger 1. For L + Rr,: by Experts tips where he wants them. Z -Ri.+j wL He also carries a small modern set with him on all calls, and when through with 2. For C: 1 k 7OR a job gives a demonstration. Many people -j FI,SH ADIO r9' YIC.0 Z- are so impressed that they buy immedi- -1cC wC Gaithersburg, Md. ately, while others drop in to the store O and buy later. (Turn to page 181)

www.americanradiohistory.com 156 RADIO NEWS FOR SEPTEMBER, 1935

S.W. PIONEERS Official RADIO NEWS Listen- ing Post Observers below by states are the Official LTSTED RADIO NEWS Short -Wave Listening Post Observers who are serving conscientiously in logging stations for the DX Corner. United -States of America Alabama, J. E. Brooks, L. T. Lee, Jr., William D. Owens; Arizona, Geo. Pas- quale; Arkansas, James G. Moore, Don Pryor; California, Eugene S. Allen, A. E. Berger, C. H. Canning, Earl G. De- Haven, G. C. Gallagher, Werner How - ald, Wesley W. Loudon, Robert J. McMahon, Oriente I. Noda, Jr., Geo. C Sholin, James E. Moore, Jr., Phil E. Lockwood, Hank G. Wedel, H. H. Parker, Fred A. Pilgrim Colorado, Wm. J. Vette; Connecticut, H. Kemp, Geo. A. Smith, Philip Swanson, J. Herbert Hyde; District of Columbia, Phillip R. Belt ; Florida James F. Dechart, George S. W. TIME SCHEDULE H. Fletcher, É. M. Law ; Georgia, C. H. Armstrong, Guy R. Bigbee, James L. LAURENCE M. COCKADAY Davis, John McCarley, R. W. Winfree; Idaho Bernard Starr, Lawrence Swen- son; Illinois, E. Bergeman, Larry Eisler, THE thirtieth installment of the Time -Table is given a List of Symbols Robert Irving, Charles A. Morrison, Phillip Simmons, Samuel Tolpin, Ray DX Corner for Short Waves con- covering the various irregularities of A. Walters, Floyd Waters, Robert L. tains the World Short -Wave Time -Table transmission, etc. Weber, J. Ira Young, Evert Anderson; for 24 -hour use all over the world. The Indiana, Freeman C. Balph, Arthur B. Affiliated D) Clubs R. Flannigan, Henry Spear- list starts at 01 G.M.T. and runs 24 Coover, J. around We are hereby placing a standing invi- ing, B. L. Cummins; Iowa, J. Harold hours through 00 G.M.T., right tation to reliable become Lindblom; Kansas, C. W. Boume Wm. the clock! This Time -Table contains a DX Clubs to Schumacher; Kentucky, Geo. Krebs, List -Wave Stations, logged dur- affiliated with the DX Corner. as Associate Charles Miller, Wm. A. McAlister, of Short Members, acting as advisers on short-wave in RADIO NEWS James T. Spalding, W. W. Gaunt, Jr.; ing the last month the in promoting Louisiana, Roy W. Peyton; Maine, Westchester Listening Post (in our Edi- activities, short-wave popu- Danford L. Adams, M. Keith Libby, well official larity and reception efficiency. A list of Vincent M. Wood, R. C. Messer; Mary- tor's home), as as at our associate organizations follows: Interna- land, Howard Adams, Jr., J. F. Fritsch, RADIO NEWS Short-Wave Listening Posts James W. Smith, August J. Walker, throughout the world. It provides an tional DX'ers Alliance, President, Charles Forrest W. Dodge; Massachusetts, Ar- hour -to -hour short -wave fans, A. Morrison; Newark News Radio Club, mand A. Boussey, J. Walter Bunnell, guide to Irving R. Potts, President, A. W. Oppel, Walter L. Chambers, Arthur Hamilton, whether experienced or inexperienced. Millen, Harold K. Miller. Executive Secretary; Society of Wireless Sydney G. The Time -Table shows the Call Letters, Pioneers, M. Mickelson, Elmer F. Orne, Roy Sanders, Donald Station Locations, Wavelength and Fre- Vice -President; Smith, Robert Loring Young; Michigan, U. S. Radio DX Club, Geo. E. Deering, Jr., Ralph B. Baldwin, Stewart R. Ruple, quency in the middle column. The col- President; the Radio Club Venezolano of M. Hpnek; Minnesota, M. Mickel - Jerry umn at the left gives the Times of Trans- President, Lo- son, E. M. Norris, Dr. G. W. Twomey; a.m., and Caracas, Venezuela, Alberto Mississippi, Mrs. L. R. Ledbetter, Dr. mission in G.M.T. the column pez; The World -wide Dial Club of Chi- Times of Trans- T. P. Watson; Missouri, C. H. Long; at the right gives the cago, Illinois, President; Howard A. Olson; Montana, Henry Dobravalny ; Nebraska, mission in G.M.T. p.m. The correspond- International 6000- to 12,500 -Mile Short - Hans Andersen, P. H. Clute, Harold ing time in E.S.T. is also given and space Hansen, G. W. Renish, Jr. ; Nevada, Wave Club, Oliver Amlie, President, Jo- Don H. Townsend, Jr.; New Hamp- has been left for filling in your own H. Miller, Vice Alfred Mannix; seph -President. shire, Paul C. Atwood, Local Time. The time, E.S.T., in the Any DX fan wishing to join any one New Jersey, Wm. F. Buhl. WJ.m. Dixon, 01 Morgan Foshay, George Munz, R. H. U. S. would be 8 p.m., E.S.T., for of these Clubs or Associations may write Schiller, Paul B. Silver, Earl R. Wick- G.M.T., as there is a five -hour difference. for information to the Short-Wave DX G. K. Harrison; ham; New Mexico, The time, E.S.T., for 13 G.M.T. would, Editor, and his letter will be sent to the New York, Donald E. Bame, John M. two Borst, H. S. Bradley. Wm. C. Dorf, therefore, be 8 a.m., E.S.T. These organization in question. Other Clubs who Capt. Horace L. Hall, Robert F. Kaiser, features can be seen at the beginning of wish to become affiliated should make their John C. Kalmbach, Jr. I. H. Kattell, each outside column in the Time -Table. W. B. Kinzel, Wm. Koehnlein, T. T. application to the Short-Wave DX Editor. Knapp, A. J. Leonhardt, Joseph M. The times, C.S.T., for these two corre- Clubs associated with the DX Corner have Malast, S. Gordon Taylor. Edmore sponding hours would be 7 p.m., C.S.T., the privilege of sending in Club Notes for Melanson, Toseph H. Miller, R. Wright, and 7 a.m., C.S.T. The times, M.S.T., for Howard T. Neupert, publication in RADIO NEWS. Harry E. ÌCentzel, the corresponding hours would be 6 p.m., A. C. Doty, Jr. ; North Carolina W. C. Couch, E. Payson Mallard, H. O. Mur- M.S.T., and 6 a.m., M.S.T. The times, Your DX Logs Welcome doch, Jr. Ohio, Paul Byrns, Charles P.S.T., for corresponding hours would be Please keep on sending in your informa- Dooley, Stan Elcheshen, Albert E. Em- this way tion on any s.w. stations that you hear erson, Samuel J. Emerson, R. W. 5 p.m. and 5 a.m., P.S.T. In Evans, Clarence D. Hall. William Oker, American listeners can easily fill in their during the coming month, getting them in Donald W. Shields. C. H. Skatzes, Carl own Local Times at the top of the col- to the short-wave DX Editor by the 20th P. Peters, Orval Dickes, Edw. DeLaet, umns. Foreign listeners would probably of the month. In this way you share your M. L. Gavin, Charles W. Krier ; Okla- homa, H. L. Dribble, Robert Woods. W. prefer to use G.M.T., anyway, or, if not, "Best Catches" with other readers and H. Boatman; Oregon, Harold H. Flick, can compute the time difference from they, in turn, share with you, making for Geo. R. Johnson, James Haley, Ernest G.M.T. and fill in their Local Time in improved knowledge on short -wave recep- R. Remster, Ned Smith, Virgil C. tion. Also send in any corrections or addi- Tramp ; Pennsylvania, Oliver Amlie, each column head. At the end of the Harold W. Bower, Roy L. Christoph, tions that you can make to the short -wave R. O. Lamb, John Leininger, Geo. Lil- L.P.O. AT BANDOENG identification charts, including station ad- ley, Edward C. Lips, Chas. Nick, Hen. slogans, station F. Polm, C. T. Sheaks, K. A. Staats. Introducing our faithful observer for dresses, station announce- F. L. Stitzinger, Walter W. Winand, Java, E. M. O. Godée ments, and any identifying signals the sta- T. B. Canfield, Charles B. Marshall, Jr.; tions may have. Our Editors are doing the Rhode Island, Carl Schradieck, Joseph working with you V. Trzuskowski; South Carolina, Ed- same thing, day and ward Bahan, Ben F. Goodlett ; South night to bring you the best and most re- Dakota, Paul J. Mraz ; Tennessee, Chas. liable short-wave information. Your logs D. Moss. Eugene T. Musser; Texas. are welcome and Are sincerely invited; Tames" Brown, Heinie Johnson, Carl Scherz, Bryan Scott, James W. Shep- Let's See Your DX Corner! pard, 'Tohn Steward. ' Overton Wilson; Utah, earl Larson, Harold D. Nordeen, Readers are also invited to .send in pho- A. D. Ross ; Vermont. Eddie H. Daven- tographs or snapshots of .themselves in port, Jos. M. Kelley, Dr. Alan E. Smith; their Listening. Posts, for publication in Virginia, G. Hampton - Allison. L. P. Morgan, D. W. Parsons. Gordon L. the DX Corner. Let . others . readers see Rich, Gaines Hughes, Jr. E. L. Myers; what yoti .and your equipment look like! Washington, Glenn ' Dubbe. A. D. Golden. Charles G. Payne; West Vir- Write 50 words naming and describing your ginia Kenneth R. Boord, R. E. Sum- receiving equipment. RADIO NEWS will pay ner, Fred C. Lowe. Jr.; Wisconsin, Wil- $1.00 for each photo used, to help defray lard Hardell, Walter A. Jasiorkowski; NEWS Wyoming. L. 'M. Jensen, Dr. F. C. expenses.- If a copy of RADIO ap- Naegeli,ric Butcher. pears in the photo, .this payment will be doubled.:.

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 157

S.W. PIONEERS Official RADIO NEWS Listen- ing Post Observers LSTED below by countries are the Official RADIO NEWS Short -Wave Listening Post Observers who are serving conscientiously in logging stations for the DX Corner. Alaska, Thomas A. Pugh. Argentina, J. F. Edbrooke. Australia, Albert E. Faull, A. H. Garth, H. Arthur Matthews, C. N. H. Richardson, R. H. Tucker. Belgium, Rene Arickx. Bermuda, Thursten Clarke. Brazil, W. W. Enete, Louis Rogers Gray. British Guiana, E. S. Christiani, Jr. British West Indies E. G. Derrick, WHERE THE GENEVA TRANSMISSIONS ORIGINATE Edela Rosa, N. Hood -Daniel. Canada, J. T. Atkinson, A. B. Baads- These are the towers and the building housing HBL -HBP, located at Prangins, gaard, Jack Bews, Robert Edkins, W. H. Switzerland. Directional beams are used to cover different sections of the world. Fraser, Fred C. Hickson, C. Holmes, John E. Moore, Charles E. Roy, Douglas Wood, Claude A. Dulmage, A. Belanger. Canal Zone, Bertram Baker. Canary Islands, Manuel Davin. Central America, R. Wilder Tatum. urdays,. 11:10 Chile, Jorge Izquerdo. Listening Post Observers and a.m., 12:10 p.m., E.S.T. China, Baron Von Huene. Other Fans Please Notice (Stevens.) - Colombia, J. D. Lowe Italo Amore. HBJ, Geneva, Switzerland, 20 meters, Cuba, Frank H. Kycd, Dr. Evelio Listed on next column is this month's 4610 kc., reported Villar. heard 2:30 -3:05 Czechoslovakia, Ferry Friedl. partial information regarding short -wave p.m., E.S.T. (Hamilton, Harris, Stev- Denmark, Hans W. Priwin, Hilbert stations, heard and reported by our World - ens, and J. H. Miller.) Jensen. Wide Listening Posts. Each item in the HBO, Geneva, 26 Dominican Republic, Jose Perez. Switzerland, Dutch East Indies E. M. O. Godee, listing is credited with the Observer's meters, same time as HBJ. (Hamil- A. den Breems, J. H. A. Hardeman. surname. This will allow our readers ton, Harris, Stevens, and J. H. Miller.) Dutch West Indies, R. J. van Om- to note who obtained the information A new station at Prague, meren. Czecho- England, N. C. Smith, H. O. Graham, given. If any of our readers can supply slovakia, will soon work on 13 and Alan Barber, Donald Burns, Leslie H. actual Time Schedules, actual Wave- 100 meters, 24 -34 kw. at 7 a.m. to Colburn, Frederick W. Cable, C. L. lengths, correct Frequencies, or any other 12 noon, E.S.T. (Stevens.) Davies, Frederick W. Gunn, R. S. Houghton, W. P. Kempster, R. Lawton, Important Information regarding these SP1SA, Poland, reported heard on John J. Maling, Norman Nattall, L. H. items, the DX Corner Editor and its 33 meters, Sundays, at 3:35 p.m., Plunkett- Checkemian, Harold J. Self, readers will be glad to get the informa- E.S.T. (Slapkowski.) R. Stevens, L. C. Styles, C. L. Wright, John Gordon Hampshire, J. Douglas tion. There are some hard stations to I2R0, Rome, Italy, now on the air Buckley, C. K. McConnon, Douglas pull in in these listings, but we urge from 8:15 -9 a.m., from 9:15 -10:15 a.m., Thwaites, J. Rowson, A. J. Webb. Listening Posts and other from 2:30 -5:00 p.m., France, J. C. Meillon, Jr., Alfred our readers to and from 6 -7:30 Quaglino. try their skill in logging the stations and p.m., E.S.T. on Mons., Weds., and Germany, Herbert Lennartz, Theodor getting correct information about them. Fris., on the 25.4 meter wavelength. B. Stark. When you are satisfied that you have They are on the air, on 31.3 meters, Hawaii, O. F. Sternemann. India, D. R. D. Wadia, A. H. Dalai, this information correct,' send it in to from 7:45 -9:15 p.m. on Mons., Weds., Terry A. Adams, Harry J. Dent. the editor; or if you have received a and Fris. (Kenney, Jr., Jensen, Libby, Irish Free State, Ron. C. Bradley. "veri" from any of the hard -to -get sta- Olson, Webb, and Baadsgaard.) Iraq, Hagop Kouyoumdjian. Italy, A. Passini, Dr. Guglielmo Tixy. tions, send in a copy of the "veri" so PC J, Eindhoven, Holland, 19 meters, Japan, Massall Satow. that the whole short -wave fraternity may now transmitting Tuesdays 8 -11 a.m., Malta, Edgar J. Vassallo. benefit. The list containing this informa- G.M.T.; Thurs. noon to 4 p.m., Mexico, Felipe L. Saldana, Manuel tion follows: G.M.T.; Suns. 1:30 p.m., G.M.T., on- Ortiz Gomez. New Zealand, Dr. G. Campbell Mac - ward, irregularly. (Donaldson.) diarmid, Kenneth H. Moffatt. PI1J, Dordrecht, Holland, RW59, Moscow, U.S.S.R., reported Newfoundland, Frank Nosworthy. 42 heard, Norway, Per Torp. meters, reported on the air, Sat- Suns. 6 -9 a.m., 10-11 a.m., 1 -6 Palestine, W. E. Frost. p.m., and on Mons., Weds., and Fris., Panama, Albert Palacio. AN ENERGETIC 4 -6 p.m. On Weds. 5 -6 a.m., E.S.T. Philippine Islands, Victorino Leonen. (Reilly, Houghton, Letroy, Portugal, Jose Fernandes Patrae, Jr. SHORT-WAVE LISTENER Hynek, Puerto Rico, Manuel F. Betances, Dodge, Mallet -Veale.) A. N. Lightbourn. The DX Corner of Mario Cassina, RW15, Khabarovsk, Siberia, 4273 Scotland, Duncan T. Donaldson. of Corona, Long Island. He has heard kc., reported heard 2 a.m. South Africa, Mike Kruger, A. C. to noon Lyell, H. Mallet -Veale, C. McCormick. all continents and 46 countries on short E.S.T. daily. (Schradieck.) Spain, Jose Ma. Maranges. waves. He uses a Silver Masterpiece LKJ1, Jeloy, Norway, reported Sweden, B. Scheierman. and a Hammarlund Comet -Pro. Switzerland, Dr. Max Hausdorff, Ed. heard 07:30 -08:30 G.M.T. (Schierman.) J. DeLopez. RV59, RNE, RV15, are reported as Turkey, Herman Freiss, M. Seyfeddin. the correct calls of the Soviet stations, Venezuela, Francisco Fossa Anderson. according to a dispatch from Moscow Applications for Official Observers in the remaining countries should be sent to L.P.O. Schradieck of Rhode Island, in immediately to the DX Corner. L.P.O. Sholin of Calif., and also Lis- tener Masuda of Japan. According to a dispatch received at RADIO NEWS, the proper calls are as shown in our OBSERVER FOR CANADA Time Table. We are writing again J. T. Atkinson explains that his s.w. to check this. receiver is a 3 -tube regenerative set. Who says DJD and ` DJB do not come in well .out west, here? Listener Haws of -Minden, Nèbraska, gets them "F. B." and He is a reporter for Berlin and should know. "The British stations have been coming in fine here in San Francisco even if a certain Eastern expert thinks it impossible.' GSC can be understood 300 feet ` from the loudspeaker. and GSB, GSD: and. GSL are all -very good." , (Gallagher, Sholin.) News in English, from foreign stations, is heard as follows: I2R0,

(Turn to Page - 160)

www.americanradiohistory.com 158 RADIO NEWS FOR SEPTEMBER, 1935

WORLD SHORT WAVE TIME -TABLE

Compiled by LAURENCE M. COCKADAY Hours of transmission for the World's Short Wave Broadcast Stations

FILL IN LOCAL TIME

11 1 2 3 4 5 8 9 10 11 M 1 2 3 4 5 6 1 EASTERN STANDARD TIME 8 9 10 N 6? 21 23 00 01 02 03 04 05 06 07 08 09 10 11 12 GREENWICH MEAN TIME 13 14 15 16 17 18 19 20 22 Wave- HOURS OF TRANSMISSION i th Call Frequency City HOURS OF TRANSMISS ON Meters Letters 4 Kc. Country D 13.9+ W8XK 21540 Pittsburgh, Pa. D DD 13.9+ GSH 21470 Daventry, England D G D 16.8+ GSG 17790 Daventry, England D O D D 16.8+ W3XAL 17780 Bound Brook. N. J. XS XX p 16.8+ PHI 17775 Huizen, Holland P P AF 16.8+ DJE 17760 Zeesen, Germany D D D D 19.4 PRADO 15440 Riobamba, Ecuador S S S HA S3 I 19.5 (HAS) 15370 TB11dapest, Hungary S S 19.5 W2XAD 15330 Schenectady, N. Y. b DD D 19.6 -I- DJQ 15280 Zeesen, Germany D- D D D 196+ W2XE 15270 New York, N. Y. D 17 D D 19.6+ GSI 15260 Daventry, England D D 19.6+ FYA 15245 Pontoise, France D P 19.7 PCJ 15220 Huizen, Holland AF 19.7 W8XK 15210 Pittsburgh, Pa. 19.7 D.JB 15200 Zeesen, Germany D O D D 19.8 F 15140 ry, gla nd D D D D D D XS XS 19.8 HVJ 15123 Vatican City 19.9+ RKI 15040 Moscow, U.S.S.R. II II DO 20.5+ JTH 14600 Nazaki, Japan - - 22.7+ ORP 13200 Ruysselede, Belg. illIff'MIENIIIIIIOM 22.9+ VP1A (VPD) 13075 Suva', Fiji Islands II 24.1+ CTIGO 12396 Parede, Portugal 11111111=1...,111111 S 24.8+ CTICT 12082 Lisbon, Portugal S V 24.9+ RW59 12000 Moscow, U.S.S.R. 25.2 FYA .11890 Pontoise, France D 25.2+ W8XK 11870 Pittsburgh, Pa. [j 25.2 -}- GSE 11860 Daventry, England DO _M 25.3+ W2XE 11830 New Ital N. Y. = 25.4 121X 11810 Rome, Italy 0 25.4 -1- W1XAL 11790 Boston, Mass. D 25.4+ DJD 11770 Zeesen, Germany ' PAP )5 5+ GSD 11750 Daventry, England Y X D D D 25.5+ FYA 11720 Pontoise, France S D D _ I b D g D D D 25.5+ CJRX 11720 Winnipeg, Canada - 27.6+ 11710 Medellin. Col. D D D D 111111677!!II 71.7!7 28.1+ JVM 10740 Nazaki, Japan Min ini lMOM 28.1+ JVN 10660 Nazaki, Japan I I saI 28.9+ LSX 10350 Buenos Aires, Argen. - II O D 29.0+ ORK 10330 Ruysselede, Belgium to 29.3+ CO9WR 10200 SanctusSpiritus,Cuba D O I ID 30.4+ EAQ 9860 Madrid, Spain Sa Sa D D I C C 31.1+ 12R0 9635 Rome, Italy C 31.2+ CT1AA 9600 Lisbon, Portugal G 31.2+ W3XAU 9590 Philadelphia, Pa. D Q D D D D 31.2+ 9590 Australia S D D 31.2+ HP5JHPSJ 9590 Panama City, Pana D S D :R:: 31.3 9580 Geneva, Switzerland $4 ß.4e7Fi1MEVii i F 9 31.3. VK3LR 9580 Lyndhurst, Victoria Australia 31.3 GSC 9570 Daventry, England XS . 31.3+ W1XK 9570 Springfield, Mass. D F 31.3+ VUB 9565 Bombay, India I I I I I 31.3+ DJA 9a60 Zeesen, Germany D D D D D Q D 0 31.4+ DJN 9540 Zeesen, Germany -_D LI LKJ1 9530_ Norway b 31.4+ Jeloy, =7NM D O D 31.3 W2XAF 9530 Schenectady, N. Y. D AK AK I 31.5+ VK3ME 9510 Melbourne, Australia DO 31.5+ GSB 9510' Daventry, England __'__''M1111711 I 31.5+ PRF5 9501 Rio de Janeiro, Braz g T 31.8 CO$ 9428 Havana, Cuba DD D 33.0+ PLV 9415 Java D XA D 32.8+ HAT4 9125 Budapest, Hungary 33.0-}- TFK 9060 Reykjavik, Iceland I' 7 Q D 34.0+ HKV 8795 Bogota, Col. I 34.2+ ZCK fiinilECI _r 12rx ík71 (ZBW) 8750 Hong Kong, China A9 AS S XS XS X 35.6+ HC2AT 8400 Guayaquil, Ec. XS Asuncion, Paraguay D D XM XM XM AI- 36.5 HCJB 8214 Quito. Ecuador S S XM 38.2+ HC2JSB 7830 Guayaquil. Ecuador 38.4- HBP 7790 Geneva, Switzerland Sd D D D 40.4+ HJ3ABD 7406 Bogota, Colombia XS XS D D 40.6+ XECR. 7380 Mexico City Mex. S XS XS L L L XS 41.7+ CR6AA 7177 Lobito, Angola, L L L_ Port. West. Africa p , 4. $ 42.0 HJ4ABB 7138 Maniales, Col. 42.1+ HB9B 7I18 Basle, Switzerland 7.h 42.3+ PIlJ 7082 Dordrecht, Holland Sa SQ 551 S 43:4+ HI3C 6900 La Romana, D. R. 44.0 I-1IH 6818 San Pedro, D. R. »iiW.6111 Walra 44. 4+ JVT 6750 Nazaki, Japan I 44.6+ TIEF 6710 San Jose, Costa Rica I D T T T 45.0+ HC2RL 6668 Guayaquil, Ecuador S Th Th Th 45.3 PRADO 6616 Riobamba, Ecuador T T D D 45.3+ RW72 6611 Moscow, U.S.S.R. I OD 45.7+ TIRCC 6550 San Jose, Costa Rica D D 45.9+ YV6RV 6520 Valencia, Ven. D D O O O O 46.2 HJ5ABD 6490 Cali, Colombia N 46.2 -1- HI4D 6482 San Domingo, D. R. XS X 0 D i,., 46.5+ HJ1ABB 6447 Barranquilla, Col, 0 0 0 SS DD

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 159

WORLD SHORT WAVE TIME -TABLE

(Continued from the Previous Page) Hours of transmission for the World's Short Wave Broadcast Stations

FILL IN LOCAL TIME

8 9 10 11 M 1 2 3 4 5 6 7 EASTERN STANDARD TIME 8 9 10 H N 1 2 3 4 5 6 1 01 02 03 04 05 06 07 08 09 10 11 12 GREENWICH MEAN TIME 13 14 15 16 17 18 19 20 21 22 23 00 wave - HOURS OF TRANSMISSION length Call Frequency City HOURS OF TRANSMISSION Meters Letters Kr. Country 11:217 CZ 46.84- YNIGG 6400 Managua, Nicaragua -MII.7 ^;iii D 47.0 YV4RC 6375 Caracas, Venez. [7r7I.7 MP: FI 47.4+ HIZ 6315 San Domingo, D. R. M nMEE FXIMEi 47.7+ HJ3ABF 6275 Bogota, Colombia WE MENEM EllEEENE 48.1+ OAX4B 6230 Lima, Peru MI MINM(MI MEN D 48.14- HJ4ABC 6230 Pereira, Colombia Mil MOM == 48.1+ H JIABII 6225 Cienaga, Colombia IMI NEMIITú 49.8+ CTIGO 6198 Parede, Portugal 11G-KiEr. NEIMF37 D I T I 48.44- HItA 6188 Santiago de Los Z Z O O Caballeros, D. R. u h uu r7 48.7+ CJRO 6160 Winnipeg, Manitoba m r . I.7 ri7I7MI 48.7+ HJ2ABA 6150 Tunja, Colombia MINNEEMI7 iii;i OM 48.7+ YV3RC 6150 Caracas, Venezuela sial r r7f7ra MIME NW. 48.7+ VE9CL 6150 Winnipeg, Man. 17U1122 MI 48.74- 6150 Cali, Colombia I7I7I7 48.7 -{- C09GCCO9GC 6150 Santiago, Cuba I-==M Mi'iiu= 48.8+ W8XK 6140 Pittsburgh, Pa. = == _ E 48.9 ZGE 6132 Kuala Lumpur, F. M. S_ 7r all 49.04- W2XE 6120 New York, N. Y. I 49.04- YDAS I =t7IalE= IM I. 6120 Bandoeng, Java 7r7r17M II7EN II.7GEE7 49.0+ HRPI 6115 San MN Pedro Sula, 7I.7 MM MEN Honduras MIMI. MI u 49.0+ HJIABE -MENEM `_ 6115 Cartagena, Col. -ice\ - LINN. Hams. l 49.0+ YVIRC 6112 Caracas, Ven. =arr:-1147MI I r7f7r7.i_. 49.0+ VE9HX 6110 Halifax, N. S ,Ár.71 1 _ Warn AMEN 49.0+ VUC 6109 Calcutta, India 7tí7 MEN MEE MK. 49.1+ W3XAL 6100 Bound Brook N J MEIN EMT-4.1 - i- 49.1+ W9XF 6100 Chicago, Ill. r M ram 49.1+ HJ4ABL 6100 Manizales, Col. 1.1 11-07N1I7 MN= : a NI7III= -, 49.1+ ZTJ (JB) 6098 Johannesburg, Africa -I<77 /alli< in ME MI 49.1+ VÉ9GW 6090 Bowmanville, Can. 7L7riEKEENBErlllI b7 : 49 :3+ CP5 6080 La Paz, Bolivia NM MENNEEMMIIIN Bafa -MIMI -- 49.3+ W9XAA 6080 Chicago, Ill. IM9t7 7&911 - 7 = == 49.3-11- ZHJ 6080 Penang, Straits NE ==M MENNEN 49.34- CQN 6073 seinats :ainew 49.3+ MaScao, MINEMMEMMMMEM al OER2 6072 Vienna, Austria 7<7I7I7

KEY TO SYMBOLS

A- Sunday, Winter only Il-Monday AB- Tuesday, Wednesday, Friday, Sat- AN- Tuesday, Saturday B- Sunday, Monday, Wednesday, Friday N-Monday, Wednesday, Thursday urday Sa- Saturday C-_Monday, Wednesday, Friday O- Monday, Tuesday, Wednesday, Friday AC- Monday, Thursday, Saturday 1)- Daily P- Except Tuesday, Wednesday AE- Tuesday, Friday. Sunday XI-Except Saturday, Sunday E- Tuesday, Thursday B- Thursday, Friday, Saturday AF- Saturday, Sunday XM- Except Monday G- Tuesday, Thursday, Saturday S- Sunday AG- Tuesday, Sunday XII- Except Thursday, Saturday I-Irregularly T- Tuesday AIi- Wednesday, Thursday, Friday, XS- Except Sunday 7- Thursday, Friday, Saturday, Sunday Th- Thursday- Saturday XSa- Exeept Saturday K- Monday, Friday V-Wednesday. Sunday AL- Except Monday, Sunday XX- Tuesday, Thursday, Friday 1.-Wednesday, Saturday Z- Tuesday, Friday AM- Monday, Thursday XY- Except Tuesday, Sunday

www.americanradiohistory.com 160 RADIO NEWS FOR SEPTEMBER, 1935

THE FAMOUS VK2ME The photograph at the left shows the 20 kw. transmitter of the Australian station, located at Radio Center, Pennant Hills, New South Wales.

latter period. (Bews and Belanger.) VK2ME, Sydney, Australia, 9590 kc., has been on the air recently from midnight to 2 a.m., from 4:30 -8:30 a.m., from 11:30 a.m. to 1:30 p.m., E.S.T. on Sundays. (Westchester Listening Post.) ZLT, Wellington, N. Z., talks to VLZ, Sydney, Australia, from about 1 -3 a.m., E.S.T. daily. Reports are verified. The address is Post and Telegraph Dept., Radio Wellington, Wellington, N. Z. (Capt. Hall.) W1OXFN, Rapid City, S. D. (The Stratosphere Balloon Tests), 47.2 meters, 6350 kc., heard testing 3 -4 p.m., and 9:30 -10 p.m., E.S.T. (Jen- sen, Young, Twomey, Barnes, J. H. IN SOUTH CAROLINA Miller, Howald, Atkinson, Gallagher, A. E. Emerson.) J. E. Moore reports Meet E. W. Duncan, a short -wave lis- the call as W1OSF10, 6/42 megacycles tener of Arcadia, South Carolina, who and time as 10:15 p.m., E.S.T. "thinks RADIO NEWS the greatest mag- W2XBJ reported heard testing on azine ever published on account of its 8.95 megacycles with music. (Gavin.) short -wave dope." His DX Corner W1OXFP, Schooner Morrissey re- is pictured. ported heard. (Roberts.) W3XAL, Bound Brook, N. J., reported on the air from 4 -5 p.m., thews, Masuda, Howald, and J. H. E.S.T., Mondays, Wednesdays, and Miller.) L.P.O. Stevens reports them Saturdays. (Christoph and Hough- on the air Mons., and Thurs., 3 -7 a.m., ton.) E.S.T.; on Tues., Weds. and Fris., W6USA, the National Exposition at 6 -10 a.m., E.S.T., and on Sats. 6 -11 3890 kc., a.m., E.S.T. San Diego, Amateur Station, and 3910 kc., with a 1 kw. transmitter, ZHI, Singapore, M. F. S., 12:30 -1 is on the air from 4 p.m. to 1 a.m. The DX Corner a.m., E.S.T. (Baadsgaard.) daily. A National receiver is used. VUB, Bombay, India, reported (Westchester Listening Post.) Waves) heard 11 a.m. to noon, E.S.T. Station XAM, Mexico City, Mexico, 11500 (Short said it would be back on the air again kc., heard testing with music, 8:30 at 1 a.m., E.S.T. (Fabius.) p.m., E.S.T. (Gallagher.) (Continued from page 157) VP1A, (VPD) Radio Suva, Fiji Reykjavik, Iceland, 9060 kc., 13075 kc., reported heard TFK, Islands, reported heard 7 -8 p.m., E.S.T. Rome, 25.4 meters, 11810 kc., Amer- 12:30 -1:30 a.m., E.S.T. except Sats. hour, 6 -7 p.m., E.S.T.; FYA, (Toohey, and Schradieck.) ican (A. E. Emerson, Howald, Atkinson; the Steamship Normandie, Paris, 11725 kc., 6 -6:15 p.m., E.S.T.; Akins, J. E. Moore, Pilgrim, Fabius, FNSK, 25.4 meters, 11770 kc., uses these frequencies for calling New DJD, Berlin, and Jensen.) kc., 7:15 -7:30 p.m., E.S.T.; RW59, Mos- York: 8830 kc., 4412 kc., 13210 SUV, Cairo, Egypt, 10055 kc., has kc., 17650 kc.; it talks to Paris cow 24.9 meters, 12000 kc., on Suns., verified reception by Hutson. 22060 Mons., Weds., and Fris., at 4 a.m., CR7AA, Lourenco Marques, 84.67 E.S.T.; JVH, Tokyo, on 20.5 meters, meters, 3543 kc., with 150 watts power, O.R.N.S.W.L.P.O. FOR MEXICO 14600 kc., 8:40 -8:50 p.m., E.S.T. daily. is on the air Mondays, Thursdays, The "Ham" and listening post of F. The British Empire "G" stations Saturdays, 1:30 -3:30 a.m., E.S.T. news from London about Saldana, whose transmitting call is broadcast (Baadsgaard.) XIDD. Other Observers in foreign 15 min. before the end of each pro- VK3LR, (3LR), Lyndhurst, Vic- gram. (Rowlett, Gates, Kuramochi, countries, hearing his signal, will kind- toria, Australia, heard 12:30 a.m., RADIO NEWS. Geiser, Bower, Baadsgaard, Akins.) E.S.T., and also heard testing from ly report reception to CT2AJ, San Miguel, Azores, 75 2:45 -3:15 a.m., P.S.T. They play rec- meters, 4000 kc., reported heard Mons., ords and give stock quotations at this and Suns., 5 -7 p.m., E.S.T. (Silver.) PLV, Bandoeng, Java, 9415 kc., reported heard Tues. and Thurs., MERRIE OLD ENGLAND 10 -10:30 a.m., E.S.T. (J. E. Moore.) O.R.N.S.W.L.P.O. Harold Self of Suf- How many got the R. N. special folk, England, sends greetings to fellow broadcast? Observers. Notice the coveted certifi- JVN, reported heard from 1 a.m., cate. E.S.T.; onward. (Best.) kc., . JBK, Kagoshima, Japan, 9120 reported heard 3 -6 a.m., E.S.T. (Sholin.) JIB, Chureki, Taiwan, Formosa, 10535 kc., 6 kw., heard until 6 a.m., E.S.T., daily. ( Sholin.) L.P.O. Donaldson reports the fol - .lowing Jap stations, testing with music irregularly: JZG, 46.36 meters; JZF, 35.27 meters; JZE, 22.5 meters; and JZD, 18.5 meters. ZCK, Hongkong, China, is now re- laying ZBW, the long -wave station at Hongkong, on a wavelength of 34.29 meters, 8750 kc., with a power of 250 watts, from 11 p.m. -1:30 a.m., E.S.T., and from 4 -10 a.m., E.S.T.. They also use another. wavelength . (65.46 meters or 5410 kc.) (Gallagher, Pilgrim, Baron von Huene, Donaldson, Mat-

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 161 CLUB NEWS

Society of - Wireless Pioneers Indian. Radio Amateurs' League A hearty - welcome is extended to the A few notes from the address of the following new members: H. J. Dent, League's President: "It is going to pay Bombay, India; H. H. Lasman, G2PX, every radio owner in India to join our London, Eng. ; Albert Fabius, Paaulio, League because we want to give all the Hawaii; F. L. Carpenter, W9NVG, Minne- lfelp we can to the radio novice as well apolis, Minn.; C. B. Sethna, VUB, Bom- as to the advanced. Foreigners will surely bay, India; A. G. Cutts, Sheffield, Eng.; welcome our League as although there R. W. Stewart, West Hartlepool, Eng.; are many clubs giving information on Fred Bell, West Hartlepool, Eng.; E. C. European and American stations, few give Edulgee, Nagpur, C. P., India. information on Asiatic stations which is Alice R. Bourk, W9DXX, has recently what they want." been confined to her bed with a severe heart attack. She manages to work her South Hills Brass Pounders rig by remote control and if her fellow and Modulators members hear her CQ, give her a word The South Hills A SMILE FROM BERLIN of cheer. Brass Pounders and C. A. Morrison was Modulators of Pittsburgh, Pa., are holding a recent visitor at their Greetings from Official Observer T. B. our test station W9QJ, and several of the annual Ham Fest at Clatty's Driving Stark of Berlin, a regular short -wave local broadcast stations Range, Bower Hill Road, Mt. Lebanon, were also visitors Pittsburgh, reporter. as was the amateur station of S. Pa., Sunday, August 4th. Meals B. will Young, owner and operator of W9HCC. be served and prizes will be distributed. - at the following frequencies: 13195 kc., News data pertaining to the Society 8815 kc., 4397 kc., 17635 kc., and should be sent direct to the office of the International Short Wave Club 22045 kc. (Kemp, Clarkson, Libby, Vice -President, 2223 E. 25th St., Minne- Reilly, Sholin and de Laet.) apolis, Minn., U. S. A. A special DX Contest will be organized HIZ, San Domingo, D.R., reported by this club during October. The judges heard on 6315 kc. (Albrecht.) Radio Club Venezolano will be Arthur E. Baer of London, Eng., J. B. CO5RY, Matanzas, Cuba, reported The new officers, for this year, of the Sessions of Bristol, Conn., Arthur heard on 42 meters. (Clarkson.) Radio Club Venezolano are as follows: H. Lynch, Clifford Denton, and others. COCD, Havana, Cuba, 6140 kc., re- Pres., R. V. Ortega; Vice. -Pres., Hermann Details of the contest will be -available next month. ported heard 10:30 p.m. to 12:06 a.m., Degwitz; Sec'y, F. F. Andersen; Under - E.S.T., playing chimes. It signs off Sec'y, Nestor Pinedo; Treas., M. S. Perez; The French with same theme song as EAQ. Ass't Treas., A. J. Sanchez; other execu- International (Gavin.) tives are, Albert Lopez L., J. G. Alfaro, Radio Show CO9GC, Santiago de Cuba, 48.7 Dr. J. A. N. Moreno, Manuel Arraez, PARIS, FRANCE -The twelfth meters, 1:30 inter- reported heard -4:30 p.m. Gerardo Sieblitz, E. J. Maury, P. P. y E. national Paris radio show organized by the and from 10 p.m. to midnight, E.S.T. Key T. "Societe pour (Donaldson.) la Diffusion des Sciences et des Arts," will be held at Paris from the TI2PG, San Jose de Costa Rica, re- An Open Letter 5th to the 15th of September, 1935. 6550 ported transmitting on kc., and Mr. A. Fabius, O.R.N.S.W.L.P.O. on 7150 kc., 500 watts. (A. E. Emer- for Hawaii, and member of the Society of SUMMER POST AT CORNWALL son.) Wireless Pioneers, addresses the following TI4AC, San Jose de Costa Rica. to his countrymen: "Come on Hollanders, N. C. Smith, our L.P.O. for England, This is the call of the new station re- let's have an Radio is shown at his summer short -wave Official News Lis- camp placing TI4NRH, and the owner plans tening Post in the Netherlands. Our coun- at Mullion Cove, Cornwall, op- inaugurating a new broadcast series erating his try is small and not well known but we portable on a mountaintop soon on 45.5 meters with 400 watts know that is now we have always occupied the power. TI4AC operating on first ranks in pioneering and certainly in the 20 -meter Ham band. (Styles.) radio engineering. Holland San de Costa Rica, re- amateurs do TIRCT, Jose not let the `Jan Salie geest' get you I" ported heard on 13100 kc., or on 13200 kc., on Tues., 6:30 -7:15 p.m., and from 9 -10 p.m., E.S.T. (Messer and Kent - THEY DO THINGS zel.) Schradieck says this is an BIG IN INDIANA harmonic. TIRCC, San Jose de Costa Rica, 300 Below: Arthur B. Coover, S.W.L.P.O. watts, 45.8 meters, 6550 kc., reported for RADIO NEWS, is shown seated at heard 6 -7 p.m., E.S.T. (Winand, his DX station. It is so large we can Betances, Stevens, Wedel, Messer, hardly call it a "corner." His letter Chambers, and Gallagher.) Schra- says, "Notice my Official L.P.O. Cer- dieck says this call is TIRCT. tificate on the lid of the cabinet." HCJB, Quito, Ecuador, now heard on 8214 kc., from 4 -10 p.m., Sundays, and on weekdays from 7:14 -11:14 p.m., E.S.T. (Sholin.) HC2AT, Guayaquil, Ecuador, 35.7 meters, 8400 kc., reported broadcasting. (Palacio and Messer.) HH2F, Port au Prince, Haiti, 49.41 meters, 6070 kc., reported heard 8 -9 p.m. except Sundays. (Betancés.) YNGU, Managua, Nicaragua, reported heard on about 33 meters. (J. E. Moore.) HRP1, San Pedro Sula, Honduras, reported heard on 49 meters, 2 -4 a.m., Malta Standard Time. (Vassallo.) HJ4ABA, Medellin, Col., 25.6 meters, 11710 kc., 100 watts, reported heard 11:30 -1 p.m., 6:30 -10:30 p.m., E.S.T. (Libby and Kentzel.) HJ4ABL is reported as the correct call for the Colombian station on 6110 (Turn to page 163)

www.americanradiohistory.com FOR SEPTEMBER, 1935 162 RADIO NEWS TELEVISION STATIONS 1\ THE UNITED STATES

Location Call Power Call Power Company Watts Company Location Letters Watts 2000 -2100 Kc. Lattera 150 Don Lee Broadcasting System Los Angeles, Calif. W2XDR 1000 Radio Pictures, Inc. Long Island City, N. Y W6XAO Jackson, Mich. W9XD 500 The Journal Company Milwaukee, %Vis. W8XAN 100 SparksWithington Co. Co. Portable of Iowa Iowa City, Iowa W2XBT 750 National Broadcasting W9XK 50 University W2XF 5000 National Broadcasting Co. New York, N. Y. W9XAKI 125 Kansas St. Col. Agr. & Apl. Sc. Manhattan. Kansas Pa. Research Co. Chicago, Ill. W3XE 1500 Philadelphia Storage Battery Co. Philadelphia, W9XAO 1 500 Western Television Camden, N. J. Mercantile Co. Bakersfield, Calif. W3XAD 2000 RCA -Victor Co., Inc. W6XAH 1000 Pioneer W1OXX 50 RCA -Victor Co., Inc. Portable & Mobile (Via 2750 -2850 Ka. of Camden) W2XDR 1000 Radio Pictures Long Island City, N. Y. W3XAK 5000 National Broadcasting Co. Portable W8XAN 100 Sparks -Withington Co. Jackson, Mich. W9XAP 2500 National Broadcasting Co. Chicago, Ill. W9XAT 500 Dr. Geo. W. Young' Portable W2XBS 5000 National Broadcasting Co. Bellmore. N. Y. W2XD 500 R. D. Lemert New York, N. Y. W9XAL 500 First Nat'l. Telev. Corp. Kansas City, Mo. W2XAG 100 R. D. Lemert Portable University W. Lafayette, Ind. Boston, Mass. Purdue 1 W9XG 1500 Y. W XG 500 General Television Corp. W2XAB 500 Atlantic Broadcasting Corp. New York, N. W9XAL 150 First Nat'l. Telev. Corp. Kansas City. Mo. (CP) 42,000- 56,000, 60,000- 86,000 Kc. CP- Construction Permit W2XAX 50 Atlantic Broadcasting Corp. New York, N. Y. SHORT -WAVE STATION LIST Arranged by Cities and Countries Continued from Last Month HCJB Quito 52:47 5,714 B NETHERLANDS EAST INDIES BOLIVIA HCJB Quito 72.95 4,110 B PNI Makassar, Celebes 34.17 8,775 P,B CP5 La Paz 49.31 6,080 B Batavia, Java 69.24 4,330 B CP6 La Paz 32.88 9,120 B PERU PKYDA2 Bandoeng, Java 48.99 6,120 B CP7 La Paz 19.60 15,300 P B P OAX4B Lima 48.13 6,230 PLE Bandoeng, Java 16.66 18.000 OAX4D Lima 51.87 5,780 B PLE Bandoeng, Java 15.92 18.830 P BRAZIL 38.34 7,820 B 16.80 17,850 P OA4C Lima PLF Bandoeng. Java B OA4R Lima 41.99 7,140 B Bandoeng. . 18.80 15,950 P PRA8 Pernambuco 49.64 6,040 PLG Java PRA8 Pernambuco 50.00 5,996 B OC I Lima 16.05 18,680 P PLM Bandoeng. Java 24.48 12,250 P OCI Lima 47.97 6,250 P PLM Bandoeng, Java 24.39 12,295 P PRAG Porto Alegre 35.48 8,450 .13 P,B PPQ Rio de Janeiro 25.70 11,670 E PLP Bandoeng, Java 27.26 11,000 P VENEZUELA PLR Bandoeng. Java 28.20 10,630 P PPU Rio de Janeiro 15.57 19,260 PLV Bandoeng, Java 31.84 9,415 P,B PRF5 Rio de Janeiro 31.56 9,501 B YV2RC Caracas 25.64 11,695 B P PSA Rio de Janeiro 18.54 16,162 B B PLW Bandoeng, Java 31.61 9,485 P YV2RC Caracas 49.05 6,112 PLW Bandoeng, Java 36.90 8,125 P PSH Rio de Janeiro 29.34 10,220 YV3RC Caracas 31.53 9,510 B PMA Bandoeng. Java 15.49 P,B PSK Rio de Janeiro 36.63 8,185 P,B YV3RC Caracas 48.75 6.150 B PMB Bandoeng, Java 14.57 20,580 YV4BSG Caracas 49.97 6,000 B PMC Bandoeng, Java 16.53 18.135 P,B CHILE YV4RC Caracas 47.04 6,375 B PMN Bandoeng. Java 29.22 10,260 P,B CEC Santiago 15.23 19,680 P YV4RC Caracas 50.10 5.984 B PMY Bandoeng, Java 58.33 5,140 B Santiago 18.91 15,855 P YV9RC El Valle 46.85 6,400 B Bandoeng, Java 49.64 6,040 B CEC Santiago 28.10 10,670 P YVQ Maracay 16.38 18.295 P Semarang, Java 68.61 4,370 B CE32 Los Andes 31.96 9,380 P YVQ Maracay 22.47 13.340 P YDB Soerabaja, Java 67.07 4,470 B YVQ Maracay 25.64 11,695 P YDE2 Solo, Java 62.33 4,810 B COLOMBIA YVQ Maracay 44.94 6.672 P YDL2 Solo, Java 62.33 4,810 B YVR Maracay 32.66 9,180 P YDA- Tandjongpriok, Java98.62 3,040 B HJA3 Barranquilla 20.06 14,940 P YV2AM Maracaibo 41.98 7,142 A Tandjongpriok, Java 49.64 6.040 B HJA3 Barranquilla 39.86 7,522 P YV5RMO Maracaibo 51.25 5,850 B YBF Medan, Sumatra 30.19 9.930 P HJA3 Barranquilla 40.14 7,470 P YV6RV Valencia 45.98 6,520 B YBG Medan, Sumatra 28.75 10,430 P,B HJA3 Barranquilla 46.73 6.416 P YBJ Medan, Sumatra 24.60 12,190 HJA3 Barranquilla 61.63 4,865 P YDU2 Medan, Sumatra 65.18 4,600 B HJA3 Barranquilla 70.55 4,250 P OCEANIA YDU3 Medan, Sumatra 57.00 5,260 B HJA3 Barranquilla 88.81 3,376 P HJ1ABB Barranquilla 46.48 6,450 B SIAM HJIABF Barranquilla 49.39 6.070 B AUSTRALIA HJIABG Barranquilla 49.62 6.042 B Call Location Meters kc. Class Bangkok 16.90 17,740 P HJB Bogota 20.08 14,930 P VK3LR Lyndhurst, Victoria 13.92 21,540 B HSJ Bangkok 37.57 7,980 P HJP Bogota 40.14 7.470 P VK3LR Lyndhurst, Victoria 31.30 9,580 B HSP2 Bangkok 31.56 9,500 B HJY Bogota 16.27 18.440 P VK3LR Lyndhurst, Victoria 51.69 5,800 E HSP2 Bangkok 31.10 9.640 B HJY Bogota 30.19 9.930 P VIY- HJ3ABD Bogota 40.48 7,406 B VK3ME Melbourne 24.95 12,020 E SIBERIA (U. S. S. R.) HJ3ABF Bogota 47.78 6,275 B VK3ME Melbourne 31.53 9,510 B RSZ Irkutsk 34.19 8,770 P HJ3ABH Bogota 49.82 6.018 B VK2ME Sydney 31.26 9,590 B Khabarovsk 70.17 4,273 B HJ3ABI Bogota 49.56 6,050 B VLJ Sydney 30.72 9.760 P RW15 HKB Bogota 30.19 9.930 P Sydney 37.57 7,980 P RW15 Khabarovsk 34.98 8,570 B P VLJ Tashkent 19.86 15,104 P HKC Bogota 47.82 6.270 VLK Sydney 28.48 10,525 P Tashkent 39.31 7,626 P HKE Bogota 42.29 7.090 B VLK- RIM HKF Bogota 37.01 8.100 P VK2ME Sydney 18.36 16,330 P HJSABC Cali 48.75 6,150 B VLZ Sydney 37.67 7,960 P AMERICA HJ5ABD Cali 46.20 6.490 B SOUTH HJIABD Cartagena 41.18 7,281 B NEW ZEALAND ARGENTINA HJIABD Cartagena 49.15 6,100 B ZL3ZC Christchurch 49.97 6,000 B 48.99 6,120 B Call Location Meters kc. Class HJIABE Cartagena ZT Wellington 24.39 12,295 P HJA7 Cucuta 55.52 5,400 P ZLT Wellington 27.29 10,990 P LQA Buenos Aires 30.91 9,700 P HJ2ABC Cucuta 51.08 5.870 B ZLT Wellington 33.69 8,900 P LQA Buenos Aires 31.23 9,600 P HJ4ABB Manizales *12.00 7,138 B ZLT Wellington 40.57 7.390 P LSF Buenos Aires 19.14 15,670 P HJ4ABL Manizales 49.15 6,100 B ZLW Wellington 24.40 12,290 P LSG Buenos Aires 15.07 19,900 P HJ4ABA Medellin 16.93 17.713 B ZLW Wellington 16.34 18.350 P LSI Buenos Aires 30.50 9,830 P HJ4ABA Medellin 25.61 11,712 B ZL2XX Wellington 62.86 4,770 P LSL Buenos Aires 29.11 10,300 P HJ4ABE Medellin 50.56 5,930 B ZL2ZX Wellington 49.48 6,060 B LSL Buenos Aires 30.09 9,964 P HJ4ABC Pereira 48.13 6,230 B LSN Buenos Aires 14.27 21,020 P HJ1ABJ Santa Marta 50.47 5,940 B FIJI ISLANDS LSN Buenos Aires 14.49 20,680 P HJ2ABA Tunja 48.75 6,150 B VPE Labasa, Vanua Levu 43.77 6,850 E LSN Buenos Aires 20.64 14,530 P Savu Savu. Vanua Levu 43.77 6,850 E LSN Buenos Aires 20.69 14.490 P ECUADOR VRO Suva, Viti Levu 43.77 6,850 E LSN2 Buenos Aires 30.32 9,890 P Viti Levu 20.79 14,420 P Aires 14.49 20,680 P HC2AT Guayaquil 35.69 8,400 B VPD Suva. LSX Buenos 4.650 B VPD Suva, Viti Levu 38.00 7,890 P LSX Buenos Aires . 28.97 10,350 P HC2EP Guayaquil 64.48 P HC2JSB Guayaquil 38.94 7,700 B VP 1A Suva, Viti Levu 28.66 10.460 B LSY Buenos Aires 14.48 20.700 B VPF Taveuni,.Taveuni 43.77 6,850 E LSY Buenos Aires 28.80 10,410 P HC2RL Guayaquil 44.97 6,668 Buenos Aires 16.55 18.115 P PRADO Riobamba 19.42 15,440 BP,B HAWAIIAN ISLANDS LSY3 PRADO Riobamba 45.32 6,616 LU5CZ Buenos Aires 42.35 7,080 A,B B KEQ Kahuku 40.68 7,370 P LST Olivos 32.93 9,104 P HCJ B Quito 36.98 8,108

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 163

Kahuku 25.67 11, 680 P heard on the air 7 -11 p.m., E.S.T. It ilton, Davis and Kemp.) Observers KKH Kahuku 39.87 7,520 P This Myers and Wood report this station KKP Kahuku 18.70 16,030 P plays 3 gongs. (Chambers.) Kahuku 18.77 15,985 P same station has been reported on on 8746 kc., and the call letters as KRO Kahuku 51.29 5,845 P 14116, 14150, 14120, 14155, 14220, 14110, HKPQ and the time from 9 -10 p.m., PHILIPPINE ISLANDS 14100 kc., by the following observers: E.S.T. ? ? ?? KAX Manila 15.01 19,980 P deLaet, Hamilton, Twomey, Chris - PRFS, Rio de Janiero, Brazil, in- KAY Manila 20.04 14,980 P toph, Phillips, A. E. Smith, Kentzel, corporates a new news program at KAZ Manila 30.01 9,990 P ' Betances. (This transmission on 8 p.m., on certain days yet to be an- KAZ Manila 36.90 8,120 P and KBI Manila 14.19 21,140 P the amateur band has been also nounced during the week. (Chris - KBJ Manila 22.64 13,240 P checked at the Westchester Listening toph.1 P KBK Manila 44.64 6,716 it is believed to be an har- YV4RC, - Caracas, Venez., has in- KTO Manila 18.47 16,240 P Post and KTP Manila 36.92 8,120 P monic of the 7058 kc. transmission creased its power to 1 kw. (Betances.) KUS Manila 16.45 18,220 P which is not heard well in the U. S.) YV5RM, Maracay, Venez., is re- KZRM Manila 25.33 11,840 B Medellin, Col., 50.6 ported heard on about 40 meters. KZRM Manila 31.33 9,570 B HJ4ABE, KZRM Manila 48.83 6,140 B (Young.) NPO Manila 33.80 8,870 T LSK, Buenos Aires, reported heard on 7460 kc., around 12:30 a.m., E.S.T. CENTRAI, (Akins.) CEC, Santiago, Chile, 28.12 meters, AMERICA reported heard from 7 -8 p.m., E.S.T. COSTA RICA (Styles.) Call Location Meters ke. Class KIO, Kahuku, Hawaii, 11710 kc., TIN Cartago 20.68 14,500 P has been reported heard broadcasting TIR Cartago 34.11 8,790 P to America for the Columbia network TIRA Cartago 31.26 - 9,590 B 'TIRA Cartago 49.31 6,080 on Thurs., 8 -10:30 p.m., E.S.T. (J. E. TI4NRH Heredia 19.90 15.075 B Moore. Gallagher, and Gavin.) TI4NRH Heredia 30.97 9,680 B TI4NRH Heredia 51.69 5,800 B TIEP San Jose 22.34 13,420 B Nairobi Changes Frequency TIEP San Jose 44.68 6,710 B TIXGP3 San Jose 51.90 5,777 B NAIROBI, KENYA, British East Africa TITE San Jose 45.09 6,650 B -Due to the interference between VQ7LO TITR San Jose 25.43 11,790 B TI2EP San Jose 41.42 7,238 A and the Danish short -wave station OXY TPK San Jose 46.10 6,504 B it was found advisable to change the fre- GUATEMALA quency of VQ7LO. Radio Nairobi has TGF Guatemala City 20.68 14,500 P changed its wavelength to 49.02 meters. TGX Guatemala City 33.48 8,955 B It is hoped that this will make it possible TGX Guatemala City 50.11 5,984 B for foreign listeners to receive the station HONDURAS with less interference. The station can HRPI San Pedro Sula 49.93 6,115 B easily be recognized by its intermission NICARAGUA signal consisting of the roaring of a lion. YNCRD Granada 41.82 7,170 B YNCRG Granada 44.99 6,664 B S.W. OBSERVER FOR OHIO Readers Who Are YNA Managua 20.71 14,480 P keeps Awarded YNLF Managua 38.50 7,788 B Carl P. Peters, of Troy, Ohio, "Honorable Mention" YNLF Managua 50.22 5,970 B a sharp lookout for new short -wave for Their YNLF Managua 69.46 4,316 B "catches" and reports his findings Work in Connection with This YNIGG Managua 46.85 6,400 B YN1OP Managua 46.99 6,380 B monthly to RADIO NEWS Month's Short -Wave Report PANAMA Roy L. Christoph, Eddie C. Zarn, Thomas HPC Panama City 29.14 10,290 P meters, 5925 kc., reported heard Kenney, Jr., A. Belanger, George C. Akins, HPF Panama City 20.70 14,486 P 11 -12 noon and 6 -10:30 p.m., E.S.T. James E. Moore, Jr., G. L. Harris, J. F. Olson, HP5B Panama City 49.72 6,030 B (Fletcher, Sholin, Young, Olson, and Jr., R. S. Houghton, James Romlett, Jack Bews, HPSJ Panama City 31.26 9,590 B J. Rowson, A. C. Lyell, G. W. Twomey, Werner RXC Panama City 38.10 7,870 P Coover.) Howald, Leonard A. Phillips, Thomas P. Jor- HJ1ABG, Barranquilla, Col., re- dan, Bob Morrison, Edgar J. Vassallo, Charles ported heard on 49.65 meters. (Coover.) E. Gates, Alberto Palacio, Thomas L. Sego, Akins says- it is heard Saturdays at Arthur B. Coover, Hank G. Wedel, Baron von The DX Corner night until 12:45 a.m., E.S.T. Huene, A. B. Baadsgaard, James L. Davis, the special H. Arthur Matthews, Anthony Slapkowski, Jr., How many received Charles B. Marshall, Jr., David Geiser, W. E. (Short Waves) Radio News broadcasts from W3XAU, Frost, W. J. Woodall, Hilbert Jensen, Billy month? (Continued from page 161) Philadelphia, last Sam Lokey, Spencer E. Lawton, Kenneth I. HJ3ABH, Bogota, Col., 50.22 meters, Albrecht, Richard O. Lamb, Richard J. South- kc. HJ4ABN is the long -wave sta- 5970 kc., 1200 watts, reported on the ward, Anthony J. Misunas, A. J. Webb, H. 2 p.m. and 6 -11 p.m., Kemp, John E. Moore, A. Fabius, Earl R. Wick- tion it relays, according to Observer air 11:30 a.m. to ham, Hen. F. Polm, Louis T. Haws, Win. Schu- Kemp. According to Observer Foshay, except Sundays. On Sundays it is on macher, Arthur Leutenherg, Paul E. Byrns, HJ4ABL has changed its wavelength the air from 12 noon to 2 p.m. and 4 -9 Philip R. Belt, Eric Butcher, H. Mallet -Veale, to 49.48 meters. According to some p.m., E.S.T. (Young, Byrns, Sholin, Arthur Letroye, Arthur Hamilton, D. Thwaites, listeners the proper frequency for A. E. Emerson and Foshay.) W. W. Gaunt, Jr., Bud Toohey, Forrest W. Col., reported Dodge, F. T. Reilly, Harold W. Bower, Edward HJ4ABL is not 6100 kc., but is 6065 HJ4ABD, Cartagena, L. - DeLaet, Lyman Chalkley, C. Clarkson, Mor- kc., judging from their verifications ? ?? heard on 49.05 meters, 6115 kc. (Bet gan Foshay, M. Keith Libby, E. C. Hutson, HJ4ABB, Manizales, Col., is now re- ances.) George H. Fletcher, L. C. Styles, Walter L. ported heard on 49.18 meters by Kent - HJ5ABD, Calle, Col., reported heard Chambers, E. L. Myers, Alan E. Smith, Walter zel, Young, and Libby. It has the 47 meters, 6490 kc., 100 watts power. W. Winand, George C. Sholin, Carl Schradieck, same announcer as HJ4ABL. (We (Young.) Robert Loring Young, Manuel Betances, S. Ku- will soon raniochi, Jerry M. Hynek, R. Stevens, Richard wish we could get this matter of these HJ1ABE, Cartagena, Col., Best, Charles W. Krier, George Provost, Fred stations cleared up officially, but have be on the air with 500 watts power on A. Pilgrim, Wade Chambers, H. Masuda, Frank not heard yet from the stations' man- its present frequency of 49.05 meters, Nosworthy, Carl P. Peters, J. T. Atkinson, Paul 180 Dowden, Robert C. Cooney, agement). ? ? ?? 6115 kc., where it now uses only B. Silver, P. Ralph HJ5ABB, Manizales, Col., reported watts. Its time on the air is reported Jose L. Lopez, E. W. Duncan, Harold J. Self, E.S.T. (Pilgrim, Wadia, E. M. O. Godee, Theodor B. Stark, Felipe L. heard on 49.05 meters. (Stevens.) as 7:30 -9 p.m., Saldana, N. C. Smith, Dwight Williamson, F. W. HJ1ABD, Cartegena, Col., is now Foshay, Young, and Kentzel.) On Gunn, Boris Scheierman, Sam J. Emerson, Al- reported on 42.1 meters, 7281 kc., in- Mondays it has a special DX program bert E. Emerson, Ken L. Sargent, Herbert L. stead of 49.1 meters. (Foshay, Vas - from 10 -11 p.m. (Sholin.) Pettey, R. C. Messer, David Geiser, Arthur G. sallo, and Rowson.) HJU2, Buenaventura, Col., reported Baurnfeind, B. L. Cummins, Inna Marr, F. L. HJ1ABJ, Santa Marta, Col., re- heard on 33.1 meters. (Palacio.) Stitzinger, Fred C. Lowe, Jr., Johan P. Curiel, Col., reported heard Duncan T. Donaldson, C. D. Hall, Antonio Fu- ported now on 5.94 megacycles, 7 -9 HJA7, Cucuta, entes L., Roberto Levi, Armand Mallebranche, 8 p.m., E.S.T., and noon to 1 p.m., on 5400 kc., 400 watts from -10 p.m., J. Ford, Carols Retelsdorfjr, S. Molem, U. Hel - E.S.T. (Palacio and Rowson.) Lis- E.S.T. (Coover.) lingman, G. C. Gallagher, Malcomb L. Gavin, is 7 -11 HJ3Q, Bogota, Col., reported heard L. T. Lee, Jr., Harry E. Kentzel, John Wojtkie- tener Hamilton says the time Ignacio de E.S.T. 8700 kc., Saturdays 9 -10 p.m., E.S.T. wic, Darrell. Barnes, H. H. Parker, p.m., Villarreal, Arthur J. Green, Michael C. Michel - HJ4ABC, Pereira, Col., reported (Clarkson.) son, H. Jackson,. Charles A. Owen, Thomas S. heard on 49.25 meters, 6089 kc. (Pala - HKV, Bogota, Col., on 33.3 meters, Baker, Herman M. Valentine, E. W. Duncan, cio and Betances.) 8795 kc., reported heard 7 -11 p.m., Edgar Plesser, D. R. D. Wadia, Irwin Beitman, its (Gallagher, Chambers, Wil- Francisco Fossa Anderson, J. H. A. Hardeman, HJ5ABE, Calle, Col., announces E.S.T. Thaddeus Grabek. wavelength as 42 meters, 7058 kc., liamson, Belt, Reilly, Houghton, Ham- Jantes T. Spalding, Hall,

www.americanradiohistory.com 1(;t RADIO NEWS FOR SEPTEMBER, 1935

the Arctic, and short-wave listeners will have the pleasure of tuning in "the voice of the Morissey" when the schooner is miles away from us. W2KJ will ably enact the rôle of "sparks" during the voyage. The call will be W1OXFP and 14,230 kc. will be the most frequently used frequency. ZCK has a power of 250 watts, is crystal controlled and operates one 8750 kc. The Hong -Kong station is rarely heard in the East. VK3LR, Melbourne, is now using 1 kilowatt power (formerly 600 watts). COCD, Havana, Cuba, operating on 6130 kc., is heard irregularly. The address is: Estacion COCD, G.Y. 25, Vedado, Ha- vana, Cuba. VE9AS, 6423 kc., Fredericton, N. B., Canada, with 50 watts input, will not be operating except on the amateur- bands until fall. This station is purely experimental and is used by the students of the University of New Brunswick in connection with their electrical engineering studies. OAX4B operates on 6230 kc. every SHORT -WAVE PAGE Wednesday from 6 to 11:30 p.m., E.S.T. This station now has a more powerful transmitter. The address is: Roberto SHORT-WAVE listeners living in the their signals, VPD, 13,075 kc., Suva, Fiji Grellaud and Cia S en C; Avenida, Aban- East Coast of the United States con- Islands, will soon fall into the category cay 915, Lima, Peru, S. A. sider logging stations in Asia, Australia of the Australian stations. This station's and the Far East proof of their DX abil- schedule is supposed to be 12:30 to 1:30 ity. While listeners located in the West a.m., but the fan who sits up every night Coast spend weary hours at the dials to hear this station is really surprised if Radio in the C.C.C. of their receivers in order to pull in the they ever adhere to this time. But by (Continued from page 138) European stations. 12:37 a.m. you will generally hear the the installation and operation of "the world's rushing sound of the carrier and within a lowest radio station", on the floor of famous few minutes Death Valley, California. an announcement. Sometimes In the nonofficial, experimental side of the EUROPEAN transmissions on the short it is "VPD, Suva, calling," or "Good eve- C. C. C. radio picture, two major problems have waves from the "D," "G" and "F" ning, listeners." In fact, you really can- loomed before the camp amateurs: power supply stations that we, the New York lis- not ever tell what they may say. VPD's and financial supply. But these boys have, with the characteristic pertinacity of the average teners, hear with fine volume are not always program may consist of American record- radio bug -and the characteristic spirit of the so well heard by the Californian. But the ings or they may test with Sydney. This new Tree Army -overcome both. Westerners do have something over us in is one station you must hear if you want "Flea- power" sets have been doing trojan in work in covering the miles and keeping civies regards to stations that are operating a verification. of the camps in touch with their homes through Java, Japan and Indo- China. This, as one the services of the vast army of amateur sta- can readily see, is just the opposite to our Logging Amateurs tions constantly on the air. These low-power Here is our Easterners' report rigs use as a "B" supply anything from batteries reception. (where no camp power is available) to camp - locals: DJD and DJA are Of late the short -wave fans have been on the foreign concentrating a majority their tuning constructed converters delivering a.c. from the received here with the most remarkable of camp's d.c. generator -unit. and of any of the Deutsch - to the 20 -meter amateur band, and no The financial difficulties have been tougher. volume clarity The average civie draws down only his "five - transmissions. GSD and GSC one knows just what you may hear there. landsenders' Countries can be logged that have not as per- month' to spend on his personal pleasures are the "D" stations' only rival, but as and needs-the - other twenty -five dollars go sign yet installed short-wave broadcasting sta- home. This is not much, if one would dabble both of these Daventry transmissions in radio. early hour and the tions, but the amateurs in these countries . off at a comparatively have been heard here with fine volume. So these radio bugs of the camps have "D" stations continue to broadcast until formed a vast company of clubs -each usually listeners listen VK2EP, a 70 -watt amateur station, can with an ex- or active "ham" as its instructor or 10:30 p.m., E.S.T., many guiding spirit -and have pooled their slender stations all evening without be heard almost nightly after midnight, to the German and his signals are remarkably strong. He resources to buy new equipment or to send home any interference. When GSC comes back for their apparatus. Others have hounded civic have had, of is on the very high frequency side of the organizations for old sets and parts. And from on the air at 10 p.m., they these gadgets they have constructed short -wave was abandoned American amateur band. ON4CSL, the late, an R -9 signal. GSL only Belgian Congo amateur we have ever receivers and transmitters. several weeks ago (for what reason we Some camp, men have been more elaborate in heard, was tuned in around 4 p.m. We their non -official experiments. "Radio Central' cannot say). It was one of the finest of name hitched France, whose do not know their power, but the signal was the impressive to the set -up the English_ radiations. was very strong. ON4AC, a Belgian in a Company at Custer, South Dakota. Two broadcasts are and have been very tem- enrollees were radio amateurs; they constructed relied upon from "ham," can be heard talking to the States a main transmitter for the camp, and portable peramental, cannot be most time. transmiter- receivers for use in the field. These many months of close at any day to day. After With all these foreign amateurs being were mounted in the camp's trucks. This hook. to our receivers, we have never up has aided tremendously in the camp's fire- application heard here, is it any wonder that the heard them with either the volume or the fighting activities. Both code and phone are or English stations. writer should have been "bitten" by the used. clarity of the German amateur bug? We have had installed in Several camps have been experimenting with The "Holland twins," PHI and PCJ, 5 -meter phone -a fine idea for "short-haul" whenever heard, which our radio shack a 200 -watt commercial - field work. One company at Morristown, N. J., have been excellent transmitter. The and another at Milroy, Pa., where the operator day except Tuesday and Wednes- built amateur in charge is every is W2IJF and our experiments begin al- is attempting to form a five -meter loop con- day. We only wish this station would necting the several camps in the vicinity, report most immediately on the 20 160 inaugurate an evening transmission and we -, 75- and - good results. a success. The station meter bands. W2IJF is a Class A operator The C. C. C. of today is far different from know it would be and has a knowledge of technical radio that time when a strange new world opened for announcer, Edward Startz, is known in the latter -day pioneers who invaded the woods liked that we regret we have not. During the in the spring of 1933. Then, busy clearing every corner of the world and well few weeks have language station an- past we been laboring ground for the camps, getting into the swing of for his friendly multi- with the study of code. We pity John a new type of life, enrollees and officials alike nouncements! Hart, our instructor, but by fall we expect had little time for radio. But today, the average EAQ, Madrid, Spain, is received with C. C. C. camp is a self -contained village of well to become proficient enough to be able wooden buildings; recreation halls, reception results. Some days they constructed erratic to pass our examination and get a much - mess halls, work shops, hospitals, comfortable are excellent, others they are not heard coveted amateur ticket. barracks and even small school buildings; and a at all. radio station is as pertinent to the unit as it is to a ship at sea. More . . it is the magnet CT1AA, Lisbon, Portugal, is an excellent which draws a large group of men who want to signal from 5:45 to 7 p.m., when it signs Other Data on study for their amateur and commercial licenses off. -or else a radio station is the goal of such a S.W. Transmissions group. The Educational Adviser (each company Now we come to a station that has not has one) in the majority of camps has added been heard by all short-wave listeners, but The well -known master, Capt. Bartlett, the study of radio to his curriculum, for the considering the fine volume and clarity of has started on his yearly expedition to (Turn to page 179)

www.americanradiohistory.com 'RADIO NEWS FOR SEPTEMBER, 1935 165

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2Ó0O B+ Z _ 2130E , W wl2 M ND 41°,2o W. By the MMCA MIC 2000V. Associate Editor HE photograph accompanying this World -Wide Reception with this article shows the new Midwest 7 -tube all -wave custom -built receiver being put through its operating tests at the West - chester Listening Post and it is only fair to remark here that the two operators who 5 -Band Receiver conducted these tests, were quite surprised at the fine results obtained, both as to sensitivity and selectivity as well as the (Midwest Model Y-7) enjoyable quality the set provides. The set incorporates new 1935 developments not usually associated with a ceramic coil forms, a compact centralized and that the parts are specially processed table -model receiver; for instance, a new bandswitch, doublet antenna provisions and to withstand unusual climatic conditions. airplane -type dial of intriguing design cali- of course, a tone control and automatic The set operates from 110 volt, 50 -60 brated in kilocycles, megacycles and in volume control. A set of this type should cycle, a.c. lighting lines. An inspection of meters. The dial also boasts of station have wide appeal to fans in both North and the schematic circuit diagram given above

group locations and an illuminated pointer South America - as well as to listeners in will show that a type 58 tube is employed indicator. Additional features include an European countries, due to the fact that in the r.f. stage which, by the way, is used automatic Select -o -band indicator, 19 tuned it has a wavelength coverage from 9 to on all wave -bands. This same type tube is circuits 8 of which are in cascade, 2400 meters (in five different wavebands) utilized for the first detector and the intermediate- frequency amplifier. A type 56 is used for the oscillator and a type 55 tube functions as a second detector, a.v.c. and an 5o audio amplifier, this is followed by a type MMFD. 2A5 7ZOPTIONA/) AR. RG. tube in the output power stage. The t--S- type 80 tube is used for rectification. r The cabinet housing the receiver and the 8 -inch dynamic type is sw2 L2A L2B L2C / 004 speaker modernistic MFG. in design. The top and sides of the cabinet S employ finished walnut veneer, while the front is of grain walnut. The dimensions 350 IO MH MMFG are 9 inches deep by inches 58 13/ wide by 20 inches high. TO GRID For the short-wave operating tests, two CAP different type antennas were used, one a doublet aerial measuring approximately 21 feet, each side of the center insulator, and a straight L -type aerial and feeder with a total length of about 150 feet. The set gave an excellent account of itself on the SW4 amateur bands, police and aeronautical ranges and it was especially good on the _ 50,000 75,000 25 and 31 meter bands. Full loudspeaker This Unit ' OHMS 1 OHMS volume was obtained without difficulty 25,000 PILOT OHMS from DJD, Germany and GSD, England

110 v on 25 meters, and from EAQ, Spain, GSC BOOSTS A.C. B+ Br-Jr and GSB, England and I2R0, Italy on 31 meters. Reception tests on the broadcast wave -band switching that can be con- band brought in many Southern and nected ahead of any short -wave receiver in Western American stations. SIGNALS a few minutes without requiring any changes in the wiring of the set. Robert Hertzberg The circuit employs type 58 tubes in the aerial directly to the receiver and the two tuned r.f. stages. The first stage turns the preselector tubes off. is regenerative and is controlled by the The tuning of the pre -selector is ANY owners of short -wave super- sim- 50,000 -ohm potentiometer mounted at the plicity itself. By slowly tuning across the heterodyne receivers are familiar lower left -hand corner of the panel. The with the annoying pre -selector dial, it will be found that at experience of re- Pre -selector tunes from 15 to 200 meters one point the signal to peat points due to poor image-frequency which the receiver in three ranges -15 to 45, 30 to 80, and is tuned will increase in volume. Then radiation, and also have had the difficulty 70 to 200 meters. It contains its own fila- of trying the regeneration control is advanced to to bring in weak station an- ment transformers but draws its plate cur- provide maximum nouncements clear enough signal strength. to be under- rent from the short -wave set. This pre -selector was tried standable. Both of these conditions with several can The pre -selector is connected perma- different receivers at different locations be overcome by the use of a good pre - nently to the set and may be switched in with very evident improvement in recep- selector, typical of which is the Peak or out of service by the control Pre- mounted tion. The instrument measures 7% inches selector herein described, a two -stage at the lower right -hand corner of the panel. wide by 9% inches tuned r.f. short -wave booster high by 10 inches deep unit with In the "off" position this switch. connects and is finished in black crackle cabinet.

www.americanradiohistory.com 166 RADIO NEWS FOR SEPTEMBER, 1935

PHILIPPINE LISTENING POST Here is where Observer George Illen- berger does his DX listening at Iloilo, P. 1. His Pilot receiver is shown on the left and on the desk a 3 -tube all - wave set of his own make.

Official RADIO NEWS Broad- cast "Band Listening Post Observers United States Alabama: Ray Wood California: Roy Covert, Bill Ellis, Ran- dolph Hunt, Walter B. McMenamy, Warren E. Winkley Connecticut: Fred Burleigh, James A. Dunigan, Philip R. Nichols, R. L. Pelkey Georgia: W. T. Roberts Illinois: Herbert H. Diedrich, Ray E. Everly, H. E. Rebensdorf, D. Floyd Smith Indiana: E. R. Roberts Iowa : Lee F. Blodgett, Ernest Byers Kansas: Vernon Rimer THE DX CORNER Maine: Danford Adams, Steadman O. Fountain, Floyd L. Hammond S. GORDON TAYLOR Maryland: Louis J. McVey William L. Bauer, William Rank. Henry Wil- kinson, Jr., Frank Zelinka (For Broadcast Waves) Massachusetts: William W. Beal, Jr., Walter C. Birch, Russell Foss, Simon Geller, Robert A. Hallett, Evan B. Roberts THE DX season will be upon us try for these DX broadcasts-and to re- Michigan: John DeMyer, Howard W. shortly and an invitation is hereby port to the stations if you hear them. Eck to DX listeners to apply for Minnesota: F. L. Biss, Walter F. John- extended Periodic DX Broadcasts son appointment as Radio News Broadcast Missouri: Dudley Atkins, III.; C. H. Tuesdays, 2 a.m., KIUL, Garden City, Kansas, Long Band Listening Post Observers. In send- 1210 kc., 100 watts. (tips.) describe Montana: R. W. Schofield ing in your application, briefly Wednesdays, 1:01 a.m., E.S.T. , W9XBY, Kan- New Jersey: Henry A. Dare, Jack B. your DX accomplishments and the equip- sas City, Mo., 1530 kc., 1 kw. (tips.) Schneider, Alan B. Walker ment you are using. Midnight (E.S.T.), WPRP, Ponce, Puerto Rico, New York: Jacob Altner, Murray Buite- 1420 kc., 20 watts. kant, Stephen Flynn, Ray Geller, Ed- NEWS Fridays, 5:30 p.m., M.S.T., CKCK, Regina, ward F. Goss, Robert Hough, Robert IT was hoped that the RADIO Sask., 1010 kc., 500 watts (tips.) be Humphrey, John C. Kalmbach, Jr., Broadcast Band converter would Fridays, 11 -11:30 p.m., E.S.T., KDKA, Pitts- Harry E. Kentzel, Maynard J. Louis, ready in time to be described in this burgh, Pa., 980 kc., 50 kw. (tips.) Harold Mendier, R. H. Tomlinson, midnight (E.S.T.), WPRP, Ponce, issue. However, there has been a delay due Saturdays, William Wheatley. Puerto Rico, 1420 kc., 20 watts. North Carolina: Marvin D. Dixon to the fact that a suitable high-capacity Sundays, 1:00 a.m., E.S.T.; KFI, Los Angeles, North Dakota: O. Ingmar Oleson gang condenser is not available as yet. Calif., 640 kc., 50 kw. (tips.) Ohio: Stan Elcheshen, Donald W. the Monthly, 13th, 2:00 -5:00 a.m., E.S.T., CM\IOX, Shields, Richard J. Southward This condenser will be available within Havana, Cuba, 1320 kc., 25 kw. coil design can Oregon: David Hunter, Walter Weber next few days. Then the Pennsylvania: Robert W. Botzum, Rob - be completed and the descriptive article Simplified World Time Chart ert Hoffman Cleaver, Edward Koesan, will be ready for the October issue. This One of the finest time conversion charts that J. Warren Routzahn, Joseph Stokes re- has yet -been produced is a compact little affair Rhode Island: Spencer E. Lawton converter has been showing excellent South Dakota: Mrs. A. C. Johnson. a which was developed and patented by Lieut. sults in tests. Used ahead of T.R.F. Charles M. Thomas of the U. S. Coast and Tennessee: W. S. Jackson. greatly increases selectivity and is a colored chart 9 inches Texas: E. Z. Kimmons set, it Geodetic Survey. This Vermont: Harry T. Tyndall. sensitivity. With a superheterodyne, it re- by 12 inches in size. Absolutely no figuring or computation is required to use this chart. It Virginia: A. J. Parfitt, C. C. Wilson sults in the "triple detection" receiver, corn- does not, like many other systems, give only the Washington: John Marshall Junior those used in several of the points in the High School Radio Club parable with time difference between definite West Virginia: Clifford Drain" transoceanic commercial stations. With the world but it actually gives the time for any hour Wyoming: J. H. Woodhead range will day or night. new condenser, the converter Through a special arrangement with Lieut. Foreign include the high fidelity channels at 1530 Thomas, RADIO NEWS can supply these' to readers. If you are interested in having a copy, ad- Alaska: S. A. Tucker and 1550 kc. Australia: Albert E. Faull, Victoria ; Tena- dress a request to RADIO NEWS, Department TC, New The "RADIO NEWS Trap- Circuit enclosing 25 cents. George F. Ingle, South Wales; which was described in the July Aubrey R. Jurd, Queensland. tuner" Canada: William H. Ansell, Saskatche- issue, is meeting with tremendous suc- DX Club Register wan; C. R. Caraven, British Colum- cess, judging by comments received from Below is the listing of the active DX Clubs for bia; Claude A. Dulmage, Manitoba; have constructed this unit. C. Holmes, British Columbia ; Philip readers who the benefit of DX Listeners who may be in- H. Robinson, Nova Scotia; Art Ling, Typical of these is the following, quoted terested in joining one or more of these organizations. For further information, address the Ontario from a ' letter written by Observer P. H. this department. England: R. T. Coales, Hants; F. R. out the clubs direct or the editor of Crowder, Yorkshire; George Ellis, Robinson, Shelburne, N. S.- "Tried Executives of clubs not listed are invited to North Stockport; Charles E. Pellatt, Tenatuner last night and it sure does forward information .to this department. London Canadian DX Relay, Goderich, Ont., Can- Ron. C. Bradley everything you said it would. It boosted ada; Fred H. Bisset, Pres. World -wide member- Irish Free State: R5 to an R7, leaving Newfoundland: A. L. Hynes, Clarenville LS2 from the noisy ship. Annual membership fee, $1.75, includes New Zealand: P. T. Kite, Auckland; most of the noise behind." weekly bulletin containing tips, club news, etc. L. W. Mathie, Hawke's Bay; R. H. Five months trial membership $1.00; one month Shepherd, Christchurch; Eric W. Radio News DX Special trial membership 25e. Watson, Christchurch Globe Circler? DX Club, 254 Cleveland St., George Illenberger Observer Kalmbach has arranged with New York; William H. Wheatley, Philippine Islands: their September Brooklyn, Puerto Rico: Ralph Justo Prats, San- Station KGFF to dedicate Pres.; Observer Raphael Geller, Secretary- Treas- turce frequency check program to the RADIO urer; world -wide membership, dues $1.25 per South Africa: A. C. Lyell, Johannes- year, issues a 6 -page bulletin twice monthly. NEWS Broadcast Band DX Corner. This International DX'ers Alliance, Bloomington, burg a frequency of 1420 Sweden: John S. Bohm, Malung station operates on Ill.; Charles A. Morrison, Pres. World -wide Switzerland: Dr. Max Hausdorff, Vi- kc., 100 watts, and is located at Shawnee, membership. Applicants for regular membership ganello must be able to meet certain definite qualifica- ` place Oklahoma. The broadcast will take tions. Membership dues of $1.00 per year ($1.25 at 5:30 a.m., E.S.T., Thursday, Septem- in foreign countries) includes subscription to the I6-page monthly bulletin, "The Globe Circler." per year, bulletins weekly throughout the winter ber 5th. tdae summer. has arranged Sample copy on request. and monthly during Observer Ray Wood KDKA DX Club, 310 Grant St., Pittsburgh, Newark News Radio Club, 215 Market St., with WPAX, Thomasville, Ga., to dedicate Pa.; Joseph Stokes, Pres. World -wide member- Newark, N. J.; Irving R. Potts, Pres. Over 2000 check broadcast to RADIO ship. No dues. No bulletin. Tips and DX in- members throughout the world. Annual dues their frequency initiation fee -$1.00 (making $2.00 total 3, a.m., formation broadcast every Friday midnight, over $1.00; NEWS 011 September 2:00 -2:20 KDKA. for first year), includes membership button or E.S.T., 1210 kc., 25 kw. National Radio Club 603 W. Market St., pin. Members receive each week DX program DX listeners are earnestly requested to York, Pa.; Robert H. Weaver, Pres.; dues $1.25 listings, news and letters from members. Local

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 161 members meet monthly in the Newark News Auditorium. Hutchinson, Kansas; 6:00 a.m., 1310 kc., WCMI, Ashland, Ky. United States Radio DX Club, Shrewsbury, Thursday: 2:20 a.m., Mass.; George D. Deering, Jr. Pres. 1370 kc., WMFD, Wil- No mem- mington, N. Car.; 3:30 a.m., 550 kc., WKRC, bership dues. Issues monthly bulletin for which Cincinnati, a charge of $1.00 per year is made. Ohio; 4:20 a.m., 1420 kc., KABR, Sample copy Aberdeen, S. Dak.; 4:40 a.m., 1310 kc., KIUJ,. upon request. - Santa Fe, N. Mex.; Universal Radio DX Club, San Francisco, 4:40 a.m., 1210 kc., Calif.; Charles Norton, Pres. WIFN Clarksdale, Miss.; 4:50 a.m., 1370 kc., KFGQ, Boone, Iowa; 5:10 a.m., 1370 kc., New Dominican Stations WPAY-, Portsmouth, Ohio; 5:20 a.m., 1200 kc., WBBZ, Ponca City, Okla.; 5:20 a.m., 1500 Observer Prats of Santurce, Puerto Rico, kc., KPLC, Lake Charles, La.; 5:30 a.m., 1200 sends in information that the Dominican Repub- kc., WAIM, Anderson, N. C.; 5:40 a.m., lic has two new stations on the Broadcast Band. 1420 ke., WMFJ, Daytona Beach, Fla. Both are located in Santo Domingo City and Friday: 5:00 a.m., 1430 loc., KSO, Des Moines, operate on 1350 kc. These stations are HIZ, 20 Iowa. watts and HIC, power unknown. Saturday: 3:10 a.m., 550 kc., WDEV, Water- bury, Vt.; 4:00 a.m., 1380 ke., WNBC, New F.C.C. Monitor Schedules Britain, Conn.; -5:10 a.m., 1210 kc., KGCR, The complete schedule of monitor transmis- Watertown, S. Dak. - sions was given in this department in the March issue. Following are the changes which bring Delete that schedule up to date as of June 25, as supplied from Washington. Monday: 2:50 á.m., 1310 kc., WHAT, Phila., Pa.; 4:30 a.m., 1200 kc., WNBO, Silverhavey, Add Pa. Tuesday: 5:00 a.m., 1420 ke., Monday: 2:40 a.m., 1310 kc., WMFF, Platts- KGIX, Las Vegas, burgh, N. Nevada, United States of America. Y.; 3:40 a.m., 1420 kc., WLEU, Thursday: 5:10 Erie, Pa.; 4:00 a.m., 1310 lee., WHAT, Phila., a.m., 1370 kc., WHBD, Mt. Pa.; 7:30 Orab, Ohio. a.m., 1370 kc., KAST, Astoria, Ore.; Friday: 5:00 7:40 a.m., KRLC, Lewiston, Idaho; 7:50 a.m., a.m., 1430 kc., KWCR, Cedar 1310 kc., KINY, Rapids, Iowa. Juneau, Alaska. Saturday: 5:10 a.m., Tuesday: 6 :40 a.m., 1310 kc., KFBK, Sacra- 1210 kc., KWCN, Water- mento, Calif. town, S. Dak. Wednesday: 3:00 a.m., 1210 kc., KIUL, Garden City, Kans.; 5:40 a.m., 1370 kc., KFRO, Changes Longview, Texas; 5:50 a.m., 1500 kc., WTMV, Monday: 2:50 a.m., 1420 kc., WHDL, Olean, E. St. Louis, Mo.; 5:50 a.m., 1420 kc., KWBG, N. Y., changed location from Tupper Lake, N. Y.; 4:20 a.m., 1260 kc., KGVO, Missoula, OFFICIAL L.P.O. HUNTER Mont., frequency changed from 1200 kc.; 6:00 a.m., 900 kc., KSEI, Anchorage, Alaska, fre- Coin .esy Observer Watson Observer Hunter, Eugene, Oregon, quency changed from 890 kc. sends in this extremely modest photo- Tuesday: 2:00 a.m., 1210 kc., WPAX, Thomas- N. Z. CHAMP'S LISTENING POST graph. Apparently he didn't quite ville, Ga., call changed from WQDX; 3:00 a.m., 1370 kc., WMBR, Jacksonville, Fla., Radio room of N. C. Manchester, succeed in hiding. location changed from Tampa, Fla. Executive Secretary o,f the N. Z. DX Wednesday: 2:50 a.m., 880 kc., WPHR, Peters- Radio Assoc. and Canterbury burg, Va., frequency changed from 1200 kc.; DX 3:10 a.m., 1420 kc., KGIW, Alamosa, Colo., champion with close to 400 veri's. location changed from Trinidad, Colo.; 5:30 The receiver is a Majestic super, a.m., 900 kc., WTAD, Quincy, Ill., frequency with a 300 changed from 1440 kc, -foot aerial grounded at Thursday: 2:10 a.m., 920 kc., WSPA, Spartan- the distant end. burg, S. Car., frequency changed from 1420 kc.; 4:30 a.m., 1500 kc., WKBZ, Muske- feet and then to 60 feet with decided improve- gon, Mich., location changed from Ludington, ment. Mich.; 4:40 a.m., 1420 kc., WCBS, Spring- "With this aerial I use a grounded antenna 50 field, Ill., frequency changed from 1210 kc. feet long and running in the opposite direction. Friday: 3:30 a.m., 1200 kc., KGEK, Sterling, This is grounded at the far end with the near Colo.; location changed from Yuma, Colo. end connected to the ground post of my set. Saturday: 3:00 a.m., 1200 kc., WJBC, Bloom- This arrangement increased volume and enabled ington, Ill., location changed from LaSalle; me to log stations which were not understandable a 5 :10 a.m., 1210 kc., KGCR, Watertown, S. usine regular ground. Dak., call changed from KWTN. "The 150 -foot antenna is noticeably directional with the lead-in taken off the end toward the Observer Hammond on desired stations." Antennas Our Readers Report - "The inverted 'L' seems to be by far the best Observer McVey (Maryland) : "I have been of any antennas I have tried. My favorite is 150 pulling in LS2, 1190 kc., almost every p.ni. feet long including the lead -in, 60 feet high, and from 7:30 to 8:30 E.S'.T." runs east and west. I have experimented with Observer Wood (Alabama) : "Heard the spe- all lengths from 50 feet to 400 feet, running in cial RADIO NEWS broadcasts from WCAU and all directions, but the length and direction men- W3XAU on July 2nd and have sent them a tioned gives me the best all -round results. report. Following are a few schedules which may "When I first erected this antenna, it was only be of interest to DX'ers: KF XR, 7 a.m. -10:30 30 feet high at one end. I increased this to 45 (Turn to page 184) U. S. Station Changes The following changes have been announced by the Federal Communications Com- 1310 New Affirmed action of February 12, mission. Abbreviations employed are: Cp- construction permit; Unitd.- unlimited; 1935, in granting application for new authority or Auth.- authorization; Spec. - special; Mod.-modification; Temp.- temporary; 1200 WHBY Green Bay, L. S. -local sunset; Lic.- license. Wisconsin. Granted alicense toy operate, 100 w. night, 250 w. day, unlimited time. 1210 WMFN Clarksdale, Miss. Granted license for new station, 100 watts, Unitd. 1500 WTMV time. East St. Louis, Mo. Granted license to operate, 100 watts, unitd. 1420 New Alexandria, La. Granted construction permit 1210 KIUL Garden City, Kans. Granted license for new station, 100 watts, (amended), 100 watts, Unitd. time. daytime only. 780 KGHL Billings, Mont. Granted special experimental 1200 KFXD Nampa, Idaho. Granted license to increase day power to 250 w.; authorization to Sept. 18. 100 w. night; Unitd. time. 570 KTAT Fort Worth, 1410 KGRS Amarillo, Tex. Texas. Granted regular license, 00íw. night, kw. day, Granted Mod. of License to change time of operation unlimited time. to Unlimited; to change call letters to KGNC and to consolidate 1240 KGKO Wichita Falls, Texas. Granted license, with WDAG; 1 kw. night 2% kw. day. regular 1 kw., unlimited time. 1490 KFBK Granted C. P. to change frequency from 1310 ka. 550 KSD St. Louis, Mo. Granted authority ending Sept. 1, 1935, to operate to 1490 kc., increase with 500 watts additional night power. 100 800 WTBO CuCumberland, Md. Granted modification of license 1370 WOC Davenport, Ia. Granted license to increase power to 250 w. day, 100 to change hours of watts night. operation from daytime to 6 a.m. to local sunset at Dallas, Texas. 250 1290 WEBC Superior, Wis. Granted license to w. increase daytime power to 5 kw.; 1010 WHN New York, N. Y. Granted 1 kw. night. Unitd. authority to increase day power from 1 time. kw. to 5 kw. 1230 KGBX Springfield, Mo. Granted Auth. to operate on 500 w. Unitd. time to 1420 WAZL Hazleton, Pa. Dec. 1, 1935. Granted extension of special temp. auth. to operate daily a maximum of 4 hours simultaneously during daytime 890 KUSD Vermillion, S. Dak. To remain silent to Sept. 1, 1935. station with 550 KOAC Corvallis, Ore. WILM, Wilmington, Del., to Sept. 30. Granted auth. to operate from 9 a.m. to 2:30 p.m., 550 KSD St. Louis, Mo. Granted and from 6:30 p.m. 9 Mod. of CP to extend completion date to p.m., PST, during month of August, 1935, Oct. 7, 1935. to instead of Unitd. time. 920 KOMO Seattle, Wash. Granted 1420 WLEU Erie, Pa. Temporary amended CP to increase day power from 1 authority granted to operate on 100 w. night, to 5 kw. 250 w. day. Unitd. time. 710 WOR Newark, N. J. Granted license to cover 920 WSPA Spartanburg, S. C. Granted license, 1 kw., daytime hours only. CP authorizing increase in 1370 KRE Berkeley, Cal. Granted license to increase day power to 250 watts; 1310 KINY Juneau, rAlaskak 100 w. night, Unitd. time. Granted license for new station; 100 watts. Unitd. time. - 1250 WTCN Minneapolis, Minn. Granted license increase to day power from 1 to 1220 WCAD Canton, N. Y. Granted Mod. 5 kw., 1 kw. night. of Lic. for increase from 9 to 12 Specified hours. a week, to hours 1210 WMFG Hibbing, Minn. Granted Mod. of operate daily except Sunday, 12:30 to 1:30 p.m., EST, CP extending completion date to 3 to 4 p.m., EST. Sept. 14, 1935. 1220 WREN, Lawrence, 1420 KBPS Portland, Ore. Granted Kans. Granted Mod. of CP to increase daytime power auth. to remain silent for the period ending 5 kw. to no later than Sept. 9, 1935. 750 WJR Detroit, Mich. Granted CP to 1370 WSVS Buffalo, N. Y. Granted auth. to remain silent to Sept. 11. increase power to 50 kw. 890 KFNF Shenandoah, Ia. Granted Special 560 WFIL Granted an increase in day time power to 1 kw. Temp. auth. to use the time assigned to KUSD for the period ending August 31, 1935.

www.americanradiohistory.com 168 RADIO NEWS FOR SEPTEMBER, 1935

Lx 2Cx

L+2L2 Ec ESG FIG.1 T r

DOTTED LINES REPRESENT of Broad-Band i STRUCTURES IDENTICAL The Design i WITH THOSE SHOWN CRYSTAL FILTERS r1 (i) W. W. Waltz w2 La Part Four THE lattice type of crystal filter ap- It will be gratifying indeed if these re- r,+2 (r2+r) (2) plied to i.f. amplifiers was discussed marks serve to awaken in the radio pro- month's issue of RADIO NEws. fession the interest which this subject WZ (L+2L2)2 in last discus- Equations were given for the required demands. Obviously enough, this characteristics of the crystals. sion of crystal filters is of the most ele- electrical is not more interest to the radio experi- mentary nature. The subject new, 2 (r2+r ) (L+ 2 L21 z (3) Of of employing crystals, but in 1- menter is the filter of Figure 1, the equiva- in a sense a and for a purpose r L lent circuit of which is given in Figure 2. using them in manner is the bridged -T type, having which some of the foremost radio engineers This filter impossible. attenuation characteristics essentially the have considered R+ r (L + M 12 (4) same as the lattice structure. X, in Fig- Bibliography whose equivalent cir- 1. LACK, F. R. "Observations on r L-M ure 1 is the crystal is shown by L., C. and Ci of Figure Modes of Vibrations and Temperature cuit the 2. The values of the elements of Coefficients of Quartz Crystal Plates," Bell FIG.3 equivalent circuit are derived as described System Technical Journal, Vol. VIII, No. above in connection with the filter in Fig- 3, pp. 515 -535. July, 1929. issue. It ure 1 on page 89 of the August 2. LACK, WILLARD and FAIR. "Some that there is a re- Improvements inc Quartz Crystal Circuit 2Zxf will be seen, however, sistance in the shunt arm which is not ac- Elements," Bell System Technical Journal, counted for in any equation thus far given. Vol. XIII, No. 3, pp. 453 -463. July, 1934. This resistance is a result of an application 3. FOSTER, R. M. "A Reactance Theo- of the bi- section theorem which was de- rem," Bell System Technical Journal, Vol. scribed in a previous article. In it (the III, No. 2, pp. 259 -267. April, 1924. resistance) is concentrated the effects of 4. JoHNsoN, K. S. "Transmission Cir- bal- coil dissipation ; that is, the resistance cuits for Telephonic Communication." New ances out the effect of the inherent resis- York, D. Van Nostrand Company. 1927. tance of the coils of the filter. In certain Pages 304 -312. sections L L4 other of the bridged -T band -pass 5. BODE, H. W. U. S. Patent 1828454. the resistance either describes method for 2 which can be devised, This patent another is not necessary or is connected into the spacing the frequency to maintain high circuit in a different manner. attenuation outside of the transmitted band. Zx 2 The value of this resistance is determined 6. MASON, W. P. "Electrical Wave Fil- ri be the resistance of L, ters Employing Quartz Crystals as Ele- 2 as follows: Let and r, the resistance of L. Then, from ments." Bell System Technical Journal, Figure 2, equivalent circuit, it can be Vol. XIII, No. 3, pp. 405 -452. July, 1934. seen that the total resistance of the induc- 7. MASON, W. P. U. S. Patent 1967249. tive branches of the line and lattice arms 8. MASON, W. P. U. S. Patent 1967250. ri and r, -I- 2 (r2 -{- r). 2Z)(4 will be respectively It can be shown that at the frequencies of 2 Zx 111 111 the transmitted band these resistances can L L be replaced by shunt resistances having the values (1) and (2) in Figure 3. When these are equal, equation (3) of we Figure 7 holds; from this equation derive the value for r. It will be seen also that the three induc- of Figure 1 form an equivalent, T; Lo tances this is, in effect, a transformer and can be replaced by two coils between which there 1111 is mutual inductance. When this is done 4, the 2x2 the circuit becomes that of Figure L2 for which are based upon 2 computations ZR the same principles as heretofore. In this case the value of R is given by the equation (4) of Figure 3. In which r is the resistance of the coils. Z. is derived from the equivalent circuit. See references 3 and 8. Figure 5 shows FIG.4 FIG.5 two other possible arrangements.'

www.americanradiohistory.com RADIO NEWS TOIL SEPTEMBER, 1935 169 Savv"iceman_ z.WITH THE GREATEST LINE OF EQUIPMENT IN RADIO SERVICING vvvvvvvvvvvv SUPREME-

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www.americanradiohistory.com 170 RADIO NEWS FOR SEPTE\iBER, 1935

LEFT: CORNELIA OTIS SKINNER

GRAHAM McNAMEE

THE MORIN SISTERS CHARLES WINNINGER

Samuel ackstage in roadcasting Kaufman

AS we are pecking out these lines on our typewriter, there are signs of a novel battle looming on the radio exponents of classical musical drama as September with his usual breezy banter on horizon. It seems that NBC's "Gibson being materially affected by radio's influ- assorted private and public lives. Family" series, the much -ballyhooed "first ence. It seems that Lawrence Tibbett and original radio musical comedy," and the other great operatic names are missing from NILS T. GRANLUND, who was a re- same network's "Show Boat" hour are next season's opera roster because of the nowned radio personality before the suddenly pursuing almost identical lines. tremendous broadcasting salaries available birth of the networks, has returned to the Just why the Gibson Family's noble ex- to such headliners at a time when the air as star of a new NBC Monday series periment in "creating a new art" went "Met" has to count pennies before doling sponsored by Bromo Seltzer. When people haywire is hard to determine. Our guess out artists' stipends. But radio fans will were still using crystal detectors and head- is that radio listeners don't care much for be glad to know that Helen Oelheim, NBC sets, Granlund (also known as Granny and radio serial dramas unless each episode is contralto, will make her debut at the N. T. G.) presided over the microphones self -contained. Anyway, it must be con- "Met" next season. Nino Martini and of WHN, New York. He deserted the ceded that Arthur Schwartz and Howard Helen Jepson are two radio personalities radio studios for the night clubs and is Deitz did a brilliant job with original words who made the "Met" requirements in pre- world -famed for his Broadway cabaret and music. The background of the revised vious seasons. Which reminds us to tell floor shows. His purpose is to adopt chorus Gibson Family programs is a traveling tent you that Nino's been quite busy before girl specialty acts to the microphone. show -Uncle Charlie's tent show, to be Hollywood talkie cameras. exact. And a very familiar person stepped THE slogan "Telling the World" is the into the role of Uncle Charlie. 'Twas none CORNELIA OTIS SKINNER'S selection fitting title to Graham McNamee's other than Charles Winninger -the original as star of the summer series of NBC Tuesday and Thursday NBC series of news Captain Henry of the Maxwell House Sunday Jergens programs was warmly comment. The series, sponsored by the Show Boat. Other aspects of the change welcomed by the nation's fans. Her noted Garcia Grande Cigar Company, like many in the Gibson Family theme point toward character sketches were occasionally broad- programs of the season, features a slogan further similarity in the two air shows. cast when she appeared in guest spots with contest for listeners. Contest ideas have The casts of each program are star -studded Rudy Vallee, but the Jergens contract rep- been adopted by many sponsors and we're and it will be interesting to observe their resented her initial weekly series. Her told that resultant fan mail has been individual progress. radio programs are selected chiefly from tremendous. her vast repertoire of stage works. She THE new deal at the Metropolitan has written about fifty stage vignettes, plus TWO prominent network trios - the Opera House under the regime of Ed- special radio material. Walter Winchell is Morin Sisters and the Ranch Boys- ward Johnson reveals America's leading scheduled to return to the program in are featured on the NBC Sunset Dreams HELEN OELHEIM NTG AND HIS GIRLS IGOR GORIN

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 171

New HIGH- FREQUENCY SOCKETS EDDIE DUCHIN series presented Sundays under the spon- by HAMMARLUND sorship of the F. W. Fitch Company. After HAMMARLUND originated low -loss, to a unique square -inset anchorage, appearing over the network on separate wafer -type Isolantite sockets, and they Hammarlund have Socket contacts cannot twist, programs, the two trios happened to try never been excelled for high frequency loosen or shift position, with changes in out their combined voices in a novel sextet work. temperature and humidity. The new arrangement and a sponsor liked the idea Only Grade "B- 100", the lowest -loss, circular Guide- Groove makes insertion and grabbed it. strongest Isolantite material is used - easier. For 4, 5, 6 or 7 prongs, 60c each list. glazed on top and sides, and "Ceresin "- treated underneath to prevent moisture The new Hammarlund "ACORN" Socket, AFTER an uneventful series of NBC absorption. for .5 to 5 -meter work, is a real low -loss sustaining programs, Igor Gorin, achievement. Extruded Isolantite base young baritone, Long leakage paths between new -type, with alignment plug: Top, sides and plug, suddenly leaped to the positive side -gripping spring contacts. radio fore by obtaining a long -term con- Due highly glazed. Silver -plated double -grip spring clips, eyeletted and tract on Dick Powell's Friday night CBS lipped "Hollywood to base to prevent shift- Hotel" series. Igor's addition ing. 1 %" diameter. $1.50 to the cast of the Campbell Soup feature each list. Write Dept. RN -9 is one of many improvements the series for Complete Catalog. has undergone since its inception about a year ago. The cast now includes Frances i Langford, Anne Jamison, Raymond Paige's HAMMARLUND MANUFACTURING CO.- Orchestra and the newspaper columnist, 424 -438 W. 33rd St., New York Louella Parsons. BLANCHE SWEET, veteran stage and screen star, was recently signed to PA -417 conduct a Monday, Wednesday and Friday series of beauty talks over CBS. Miss Sweet, of course, is still best remembered PUBLIC for her screen roles of the silent era. Last season, New Yorkers saw her on the ADDRESS Broadway stage in "The Petrified Forest" with Leslie Howard. She was born in SYSTEM Chicago and represented the third consec- utive generation of her family to pursue With Crystal Mi- a theatrical career. She made her radio crophone and Mu- debut five years ago in Los Angeles. sical Background WITH Ed Wynn taking a long vaca- Mixing System. tion, Eddie Duchin, the young maes- Single or Dual tro of the Texaco. NBC Tuesday series, Speaker System. has been assigned the featured rôle. As Duchin's orchestra crossed the nation on a A Webster- (Turn to page 183) Chicago BLANCHE SWEET Product A Portable System that combines sev- . . . high fidelity and easy portability eral new and important developments ... are other features of this new Web- such as . a high -gain four-stage am- ster- Chicago unit. For indoor installa - plifier having an output of 17 watts . - tions of the larger type. Tubes, two 57, a 12" dynamic speaker with 50foot three 2A5, one 5Z3. Power required, speaker cord and plug ....crystal micro- 110 watts. Weight, 42 lbs. phone mounted in a 12" desk stand. Ask for Bulletin Mixing arrangement with musical background ...crystal microphone with THE WEBSTER COMPANY frequency range of 50 to 10,000 cycles 3826 W. Lake St Chicago

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www.americanradiohistory.com 172 RADIO NEWS FOR SEPTEMBER, 1935 Listen to C -W Signals THE SERVICE BENCH your present on tells YOU something about all -wave receiver The RCA Beat Oscillator is easily connected to any err zctng superheterodyne receiver, permit- ting beat reception of c -w sig- Equipment nals. Has vernier adjustment for controlling the pitch. Powered from receiver. Uses either ABROADw 2.5 or 6.3 volt tube. Net price, $7.50

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Contains 92 pages, . lists thousands of parts for replacement rm in any set; special re- PRRTS placement parts guide i -7- r" RRUT FOR THE for RCA Victor, G. E.,

épE,pLT1E5 ENGINEEN a Ola SEftCE Westinghouse and Graybar sets. Tube Charts. Diagrams. Ask your RCA parts FIGURE 1 distributor for a free copy.

RCA PARTS DIVISION RCA MANUFACTURING CO., INC. Conducted by Zeh Bouck, Service Editor CAMDEN . . . . NEW JERSEY SERVICE -HANDS son why an auto -radio could not be installed in the roomy carrier with the ACROSS THE SEA speaker baffled agaist the dummy screen- FOREIGNOREIGN members of the fraternity ing, combining audible with visual appeal. contribute the photographs of Figures Whatever they may say about the 1, 2, 3 and 4. Writing from the Scotch, certainly expenditures have not been balmy clime of Teneriffe, in the Canary stinted in the exceptionally neat service Islands, Americo L. Mendez thanks the bench illustrated in Figure 2, designed and Service Bench for the ,salës` idea shown in built by R. Halliday, of Glasgow, Scot- Figure. 1. ' "This special automobile has land. Mounted on the panel are an all - demonstrated impressively its value as an wave modulated oscillator, a tube tester advertisement. The idea was brought to which accommodates all American, British my attention by a photograph in your last and Continental tubes, testing them either September issue -page 172, Figure 2. Any on the bench or in the receiver, voltmeter, serviceman can have confidence in the ammeters and ohmmeter, 110 to 250 volts sales promotional effect of this arrange- a.c. and d.c. outlets, a neon tube continuity ment." tester, and power outlets for testing bat- The body of this radio truck should be tery receivers. The motor at the extreme well within the capabilities of the average left drives a coil -winding machine, on serviceman to construct. There is no rea- which everything can be wound from a

FIGURE 2. WELL- EQUIPPED GLASGOW SERVICE SHOP With New -Type CARBON RESISTANCE just another volume control -but the NOTmost advanced volume control ever offered the service man and experimenter. It has uncanny quietness, and smoothness which improve with use. All standard and special values.

`g35 ELECTRAD, Inc. 175 Varick St., New York, N. Y. Please send new Resistor Cata- log . Cheek here for folder on. new QUIET Carbon Control.

www.americanradiohistory.com RADIO NEWS FOR SEPTEIDIßER, 1935 173

OHMS 3 75W- 20,000 OHMS -- -, 80

50 OHMS o--cree o- FUSES FI G.5 V:

4 ïäi`:: TRANS- FORMER UNDER TEST Cash Prizes J for Servicemen J i0: RADIO NEWS is offering five .-.- cash prizes of $10.00, $5.00, .. Uri $4.00, $3.00 and $2.00 each month mY 5 I; t of e waY for the best ideas sent in by active 10 ocei1 servicemen for promoting the ser- "l vg e d S ol t o vice business. In addition, a one - out oî lT year subscription to RADIO NEWS -e o to tnne will be given for such ideas, other t o Sol S than prize- winning, that are print- Tun nas á11tY ed. Send in as many suggestions as you wish. The more the better! ftlet A 'a e " dl What has helped you ring up the ttybe cash register may do as much for t, a brother servicemen and bring E bugUe you in some prize cash besides! F lowa Address contributions to the Ser- lO8 p C1tY vice Contest Editor. FIGURE 3

power transformer to an r.f. choke. Mr Halliday's letterhead describes him as a "radio electrical engineer" and the manufacturer of "high -grade electrical and radio apparatus." Figures 3 and 4 are views of the service shop operated by Enrico Cortez, of Milan, Italy. Figure 3 shows an audio oscillator, power amplifier and loudspeaker under repair, Signor Cortez specializing in work of this nature. To the right, in Figure 4, are a tube tester and radio -frequency oscillator. On the panel to the left are mounted the various components of a es tester designed for servicing power trans- FIGURE 4 formers, the circuit of which is shown in Figure .5. Switch "R" controls the voltages highways. A thorough check on tubes ór e-t.o5 iase to the auto -transformers, while switch "S" and set eliminated this section of the in- varies the input to the transformer under stallation, and the trouble was finally 5stla Sol ve£O1a1%0eto ug aail$ . test and automatically maintains the cor - traced to a loose connection between S orq setailes se ' . the ,Sol rect resistor values in the voltmeter sec- lead -in and antenna. A careful soldering ed ae tion of the wattmeter. The wattmeter job effected the repair. by S h . is switched in and out of the circuit by Dial trouble on a Ford 1935 V -8 has 'sp ves£os pecisexr ts "I." Jacks "X" and "X" are provided occasioned several service jobs for B. F. UC om ra for plugging in milliammeters. The load Goggan, Henderson, Texas. Jumping of alt5 ó s o. of the filament -lighting secondary can be calibration is the usual complaint. Re- $ {aot°s'rase£v 11Y'tsa' ts varied by rheostat "A." move the cogwheels from the dial assem- as``a s bly. With le a light hammer, gently beat irgb9ó rrel'aatiorSt° . THE. DAY'S _ WORK . the cogwheel that holds the pointer until ess vasi esar ces As auto -radio troubles hit their peak it thoroughly meshes with the intermediate tol just toward the close of the vacation sea- driving gear. Simple and permanent. syal son, a few relevant contributions are in bolalsttrarv order. Three Service Bench readers report Permanent Cure for Vibrator troubles with Ford V -8 installations. L. Rectification Troubles C. Warren, proprietor of the United Radio "A short time ago Service, an Emerson auto - Sioux Falls, S. D., writes: "Every radio set was brought in 1935 Ford V -8 with vibrator requires a condenser on the trouble. The owner was insistent oil gauge. The oil gauge is a set of on get- resis- ting the set into working order that day. tor plates in series with a meter, and The vibrator was not rectifying, hooked directly to the and there hot "A." Vibra- wasn't another unit to be had, tion of the car causes these contacts in town. TUNG -SOL to set We decided to up substitute a full -wave type a disturbance which sounds like a noisy 84 rectifying tube in accordance CoYl.Q tube. In most cases, with the radio aLge& the condenser should diagram of Figure 6. be hooked directly to the oil gauge on the "The five -prong block. socket was mounted on TUNG -SOI RADIO TUBES, Mount the condenser on the fire - the receiver chassis. Room Inc. wall beside the steering °column." for this tube SALES OFFICES will be found in almost every receiver. Frank E. Martin, of the Supreme Radio ATLANTA, BOSTON, CHARLOTTE, The filament was connected in parallel with Service, Crowley, La., reports noise of those of the other CLEVELAND, CHICAGO, DALLAS, DETROIT, rough roads tubes. The vibrator was - occasionally intermittent re- disconnected from the KANSAS CITY, LOS ANGELES, NEW YORK ception. Perfect operation transformer secon- oii-the good (Túris to page' 184) GENERAL OFFICE, NEWARK, N. J.

www.americanradiohistory.com 174 RADIO NEWS FOR SEPTEMBER, 1935

Announcing WHAT 'S NEW IN RADIO the two WILLIAM C. DORF LOWEST (Continued from page 139) Build Your Own PRICED standing of which is the "clover- leaf" ar- Condenser Tester rangement of coils,' aligning condensers and The Thordarson Electric Mfg. Çompany high powered portable range switch. offers a foundation unit, or a complete kit Universal Oscillograph PA Systems! With the new, Westinghouse type PA oscillograph it is possible to view the fre- IT'S headline news when U. S. E. makes quency pattern while it is being photo- such an announcement. To appreciate range the unprecedented value in these new low - graphed. The instrument has a wide priced U. S. E. items, consider these fea- of film speed, and features interchange- tures: UL -18 Portable PA System Complete with: Ribbon microphone. 12" dynamic speaker. 18 watts output using type 45 tubes. Built -in mike-phono fader and tone control. Assembled in handsome carrying case with cords, plugs, etc., complete. ALL FOR $125.00-LIST PRICE Code Word "ANLAR" UL -16 Portable PA System Same features as above except with 16- able galvanometers and vibrators. The in- watts output and supplied with double -but- laboratory types are available ton carbon mike. dustrial and for operation on either six volts d.c. or ALL FOR $87.50 -LIST PRICE Code Word "ANLEC" 110 volts a.c. or d.c. current. Write or wire your U. S. E. Distributor Photo- Cell or this factory for literature on these out- Electric of parts for the construction of their new standing values. This new Eby photo -electric cell is avail- combined condenser capacity and leakage 5 Days Free Trial If -You Wish able either singly, in assemblies containing tester. The foundation unit comprises a cell, relay, tube, resistances, socket, etc. portable Walnut instrument case, an etched UNITED SOUND or in handy kits for home or laboratory and drilled metal panel and scale, mount- experimentation. The manufacturer states ing screws, instructions and assembly ENGINEERING. COMPANY that it is unaffected by continuous ex- plans. A Wheatstone Bridge circuit is used Manufacturers of Special/teed Sound Equipment posure to light and it reacts to both the for capacity measurements and leakage is 2229 University Avenue Saint Paul, Minnesota indicated by a neon bulb connected in

series with a high- impedance . choke coil. Mixing Panel WHEN CHOOSING The Webster Company introduces the model No. 104 microphone mixing panel and pre -amplifier. With this unit it is pos- A RADIO SCHOOL sible to mix the output of either carbon or RCA Institutes, with its reputation firmly established by 26 years service, is an institution recognized as an important factor in the radio industry. Whetherr elementary radio principles or advanced subjects, sound applications, mathematics or practical radio engineering, RCA In- stitutes is prepared to give you the instruction you need. ribbon type microphones and low imped-

. - frequency of the incident ance pick -ups. The two -stage battery Resident Schools at New York and Chicago intensity and the type 30 light -rays. It bas low internal capacity operated amplifier employs tubes. Modern Apparatus and Laboratory and is sensitive in both the generative and Equipment -Conveniently Located emissive classes. A New Instrument for the -Day and Evening Classes - Serviceman Tuition Rates $3 to $10 Weekly. - Multi -Purpose Tester The Triumph model 500 condenser The Supreme model 385 "Automatic" bridge -analyzer has been produced for Extension courses for home study combines the features of the Supreme ana - on convenient "no obligation" plan. lyzer and tube tester, plus additional test- Examination and technical advisory ing developments. It has three ohmmeter services. Free post- graduate practical training at resident school with modern equipment under instruct- =_ ing engineers. Write for Catalog. RCA INSTITUTES, Inc. Dept. RN -35

75 Varick Street NEW YORK measuring coils, resistors, power factor Mart 1154 Merchandise point -to -point analyzing facilities, and continuity and for measuring and CHICAGO ranges, a capacity tester, and a tube checker for checking condensers. It operates from 110 - supply. Recognized Standard in Radio Instruction Since 1909 all tubes, including the new metal tubes. ' volt, 60- cycle, a.c. power

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 175

NEW VOLUME OF SYLVANIA'S SERVICE HINTS Now READY!

It's Crammed with Brand New Material . . . Service Tips from Crack Service Men All Over the Country SEND FOR YOUR FREE COPY TODAY 56 FOOT TWIN -SCREW CRUISER CARRIES RADIO INSTALLATION A Philco radio receiver, the tuning dial of which can be seen in an inconspicuous position just above and to the left of the wheel, furnishes Mr. F. V. Desloge's B.C.F. express cruiser "Nimraf" with excellent radio reception in the forward and after cabins and also in the deck house.

A Low -Cost Resistance Bridge arrangement. Specifications are: power output 11 watts An announcement undistorted, 20 watts has just been received maximum, gain 108 db. and when operated from the Muter Company of their new Wheatstone type bridge featuring accuracy, simplicity of operation and ruggedness. The resistor elements are wound in strip form, the taps being set to an extreme degree of accuracy. Thorough vacuum

Maybe you are one of the 50,000 radio service- impregnation insures freedom from varia- with its associated speaker system the over- men who sent for Volume 1 of Service Hints. Then you'll be sure to want Volume 2 of this tion due to changes in humidity and a all response is said to be flat from 4 to booklet, because it has snore of the same helpful service tips inside special alloy resistance wire is employed to 10,000 cycles. ... dope on special problems . . . but every bit of it brand new material ! maintain constant resistance regardless of New Uni- Directional Crystal This new volume of Service Hints contains the pick reasonable changes in temperature. of service items sent in by thousands of service men Microphone . every one of them up -to- the -minute solutions of ,everyday problems. It's The Brush model UD3 microphone compiled for men who are Small Size Electrolytic re- always willing to learn more about radio . and Condensers sponds only to sounds originating on its it's a short cut to better servicing and better profits. active side, which extends over a field of Don't wait. Send today for Volume 2 of SYL- The new Solar series of small -size dry 180 deg. The restricted field VANIA SERVICE HINTS. It will iron out a lot of of sensitivity your troubles, and put you in line for more and e'ectrolytic type condensers are called of this new microphone reduces interfer- better service jobs. There is no charge. Simply "Little Giants" due to the fact (Turn to page fill out and mail. Mail this coupon today and you'll that they 183) get your copy of this valuable booklet are only one-half the size of the previous in a few days. Hygrade Sylvania Corporation. Makers of Sylvania Radio Tubes and Hygrade Lamps. Fac- tories at Emporium, Pa., Salem, Mass., and St. Mary's, Pa.

COMPACt DRY Et EC TRotYr, o CAPACITOR asso.

The Set- Tested Radio Tube midget type condenser, without any sacri- fice in electrical quality. They are r- ."1 avail- Hygrade Sylvania Corporation, able in 200 and 450 working voltage rat- Emporium, Pa. in RNA ings and all standard capacities Please send me free, without obligation, Volume 2 of Sylvania's "Service Hints ". Latest Sound System for Experimenter Amateur Call Theatres Serviceman Employed by dealer Independent The new Pacent high -gain, high -fidelity Member Service Organization 5- tube amplifier, designed primarily for Name use with talking moving picture equip- Address ment, is also adaptable to all manner of City State P. A. work. It is equipped with low- and Name of Jobber high- frequency attenuators and a fader Address IL -J

www.americanradiohistory.com 176 RADIO NEWS FOR SEPTEMBER, 1935

SPR p,GU E

NatANALYZER $9.75 NET (with Adapters)

SHOW CUSTOMERS WHERE INTERFERENCE ORIGINATES . . . THEN ELIMINATE IT! TECHNICAL REVIEW At last -a quick, practical way for THE eliminating radio interference from CONDUCTED BY ROBERT HERTZBERG ANY electrical device. No more guessing. No lost time. First you with the Electric Circuits and Wave. Filters, by Short -Wave Manual, second edition, 32 actually eliminate the noise 9 inches. Hammarlund Mf g. Analyzer. You show customers just A. T. Starr. Pitman Publishing Corp., pages, 6 by 1935. Good books on filters are scarce Co., publishers. Short -wave constructors what proper filtering of appliances in this little ten -cent booklet, will do. Then, from the instruction and, in fact, the better part of the latest will delight information is found only scattered in va- which is devoted to detailed descriptions sheet, you learn what Sprague filter short -wave receivers condensers or chokes to install to rious technical journals. Engineers and of thirteen different will want to study this of tried and reliable design. The diagrams insure exactly the same results as advanced students are indi- new orderly treatment of the subject of are clear, the values of all parts those obtained with the Analyzer. coil- winding data are Inexpensive -will quickly pay for filters. The book begins with a brief re- cated, and accurate itself in new business it helps you view of mathematics, including determi- included. series, See it at Sprague jobbers nants, progressions and binominal of the - build. loga- Theory and Principles Cathode or write for catalog. !SPRAGUE algebraic notation, exponential and by F. L. Sprayberry. 37 trigonometric functions, Ray Oscillograph, PRODUCTS CO., North Adams, rithmic functions, pages, 11 inches, loose -leaf binder. complex num- 8/ by Mass. real hyperbolic functions, F. L. Sprayberry, publisher. To many By the makers of bers, hyperbolic and trigonometric func- oscillograph is a mys This radio servicemen the - tions, linear differential equations. terious device mainly because they do not chapter is in the nature of a brief review understand its operation. This book, a :PRAGUE - and not a course in mathematics. The Sprayberry Course and written fundamen- part of the CONDENSERS second chapter deals with the in clear, specific language for the practical Radia Siervre SPRAGUF tals of alternating current theory, the third veil of h.o beamemviceafhe I6LINE service technician, tears away the t .u.rxanes+m with the theory of electric circuits. The mystery and shows how the cathode -ray coils, condensers is 11111I III IIII11111 III 111111111I111IIIIIIII III IIIIIIIII design of resistances, oscillograph can be an extremely valuable next in order. Thereafter the reader is the general theory then service tool. It describes introduced to two -terminal networks, of cathode -ray devices and explains in de- four -terminal networks and finally filters. patterns formed on the wYoN and tail how the wave Q,, The treatment is orderly, logical screen can be interpreted to indicate va- necessarily mathematical. A knowledge of rious circuit conditions and phenomena. and differen- w4:0,_ hyperbolic functions, calculus The progressive serviceman (and also NEW LOW tial equations is required to obtain the advanced amateur and experimenter) text. the PRICES greatest benefit from a study of the will certainly benefit from this study. TOO Guida Pratica del Radio Riparatore Review of Articles in the June, , by (Practical Guide to Radio Repairing) 1935, Issue of the Proceedings of A quality E. Costa, published by Ulrico Hoepli, Milan, Italy, 1935. A book on servicing the Institute of Radio Engineers transformer equipment and servicing for those who Image Suppression in Superheterodyne group at read the Italian language. The book is Receivers, by Harold A. Wheeler. Super - into three parts. The first part heterodynes' are notoriously sensitive to in- low prices. divided image deals entirely with measuring instruments, terference at the intermediate and frequencies. To overcome this trouble, the Quantity pro- oscillators, tube testers, vacuum -tube volt- alone takes 230 pages. author describes several types of selective duction at meters. This part the quality stand- The second part is devoted to a discussion circuits for coupling the antenna to with the most modern and advanced manu- grid of the first tube. ards Kenyon of condensers, coils, transformers and re- facturing equipment has enabled how they to produce a high performance transformer and sistors, their characteristics and Testing of Multirange group at startlingly low prices! The third part The Design and reactor are used in radio circuits. Receivers, by Daniel E. Hartnett and Nel- deals with the real servicing problems. in to date son O. Case. The principal difficulties The book appears to be quite up wave" receivers lie in addition to the the design of "all- the SILVER and should be a welcome the complexity of the multi -range circuits. who read Italian. library of servicemen Several circuits and a unit assembly ar- PERFORMANCE- improve silver group units are electro- rangement are described which All magnetically How to Understand Electricity, by A. calibration and simplify the statically and electro- pages, by the frequency shielded. Frederick Collins, 326 5/ 8/ design. Testing is facilitated by the use inches, cloth covers. J. B. Lippincott having "pis- DEPENDABILITY - this of simplified signal generators All silver group units sealed with a Company, publishers. The aim of ton" attenuators. humidity proof high melting point book is to acquaint technically untrained compound assuring depend" opera- the fundamentals of elec- Expanding tion. persons with High- Fdelity Receivers with tricity, taking them in progressive stages by H. A. Wheeler and J. Kelly LONGEVITY Selectors, - from simple magnetism to . gen- All silver group units are double all the way Johnson. A high- fidelity receiver for vacuum impregnated under an in- X -rays and electrical measurements. The eral use requires a means of expanding or sulating varnish assuring maximum has kept mathematics at a minimum the resultant band width, in efficiency. author contracting operating and where he does show a few simple for- order that the best compromise between mulas he works them out. fidelity and selectivity may be chosen. The language throughout is simple and This paper describes a superheterodyne lucid, being aimed obviously at the casual which has a preferred form of symmetrical type of reader who prefers his technical expanding selector, as well as other fea- education in easy steps. While the treat- tures ment of many subjects is rather sketchy, Kenyon Transformer Co.. Inc. basic facts and actions are explained under- Acoustic Testing of High- Fidelity Re- 838 Barry Street. New York. New York standably. ceivers, by H. A. Wheeler and Vernon E.

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 177

Whitman. Description of some interesting Analyzer Booklet tests of receiver operation under home The Supreme 391 P. A. Analyzer is the title conditions. of a 12 -page booklet describing the applications of a special analyzer made for servicing public - High -Quality Radio Broadcast Trans- address and sound film equipment. Contains Reception, by Stuart Ballan- seven diagrams and practical data of value to mission and sound technicians. Copies of this booklet may tine ; The Receiving System. More valu- be obtained free of charge from RADIO NEws, able data on the electro- acoustic fidelity 461 Eighth Avenue, New York City. of broadcast receivers, dealing mainly with the technique of loudspeaker placement. Review of Contemporary Literature A Review of 20 Years of Progress in Communication -Frequency Measurements, General Radio Experimenter, June, 1935. The whole 20 -page issue is devoted to an interesting, brief review of the history of the G. R. Co., long famous for its measuring equipment. Transformer Bulletins The Behavior of High Resistances at Catalogs R -1 and C -1 of the Kenyon Transformer High Frequencies. The Wireless Engineer Company lists a very complete line of trans- (London, June, 1935. The distributed formers and choke coils for replacement, public- capacity of fixed resistors, which is unim- address and amateur purposes. Several audio frequencies, becomes amplifier kits are also described. To obtain cop- portant at ordinary ies free of charge, write to RADIO NEWS, 461 appreciably noticeable at the very short Eighth Avenue, New York City. wavelengths, an effect discussed in detail in this informative article. Sound Equipment A description of a line of sound apparatus, The New 838 Zero -Bias Triode. R /9, ranging from microphones to rack -and -panel sys- June, 1935. Practical operating data on a tems, has been published by Sound Systems, Inc. The sound technician, dealer and broadcast engi- tube especially suited for medium-power neer will find this circular useful for reference amateur and communication transmitters. purposes. To obtain a copy free, write to RADIO THE HRO .. For NEWS, 461 Eighth Avenue, New York City. Directive Antenna Systems for 14'3'Ic. Operation, by John D. Kraus. R /9, June, consistent 'reception. 1935. ambitious amateur with a big The Designed reliable back yard will find this "dope" useful if he for reception under wants to improve his transmission. adverse conditions, as well as great ease of control, the HRO communications The Use of Condensers in Radio Re- type receiver represents the highest type ceivers. The Aerovox Research Worker, of short wave receiving equipment. stuff on April, 1935. Good educational From worm -drive precision condenser to the use of fixed condensers for coupling, single signal filter, no detail has, been; blocking and by -pass applications. omitted that could .contribute. to . its

The Present -Day Status of Broadcast superlative characteristics. ._ 1935. NSW R+NOSERVncE(t Synchronizing. Electronics, June, .áanx*x,.i..i..F..o.w.».< Its outstanding features include: Nine tubes, not Three systems now operating successfully -_. m==tLSt>so0 point the way to expansion of broadcast - including rectifier Two Preselector Stages Amateur Equipment Catalog Single Signal (Crystal Filter) standard equipment facilities. This article reviews the meth- Ganged Plug-in Coils, with each coil individually ods used and points out that improved re- A 48 -page catalog devoted to amateur radio shielded single -control Tuning Cali- equipment has Strictly ception conditions and wider service areas been brought out by Wholesale bration For each range mounted on coil Four - Radio Service Co., Inc., New York. The book are possible. contains about a dozen pages of helpful technical gang Precision Condenser, with preloaded worm - drive tuning, 20 -1 ratio Micrometer Dial, A Police Radio System for Newark, by data, diagrams, lists of Q signals, etc. Readers can obtain copies, free of charge, by writing to spreading tuning over 500 divisions, numbered Arnold B. Bailey. Bell Laboratories RADIO News, 461 Eighth Avenue, New York every 10 divisions, direct reading Automatic Record, June, 1935. Description of an City. or Manual Volume Control Vacuum Tube high- frequency one -way Voltmeter with Instrument calibrated in S scale of up -to -date, ultra- RADIO NEWS Booklet Offers Repeated system that already is proving highly suc- carrier intensity Electron Coupled, air -padded oscillators Two I. F. stages with is For the benefit of our new readers, we are Litz -wound cessful. Of particular interest the an- repeating below a list of valuable technical coils, air condenser tuned Beat Frequency tenna, which is grounded to its support booklets and radio manufacturers' catalog offers, Oscillator for "Offset" C. W. Tuning Phone on the roof and energized by a coaxial which were described in detail in the June, July Jack on Panel 21/2 Volt AC and 6 Volt AC or and August, 1935, issues. These booklets (J1 Battery models Relay Rack Mounting available. conductor. to J9, Jy2 to Jy5 and Al to A5) are still avail- Noise -Suppression Antennas, by W. F. able to our readers free of cost. Simply ask Send coupon below for descrip- 1935. The second for them by their code designations and send Osier. Service, June, your requests to Radio News, 461 Eighth Ave- tive booklet and General Catalogue and concluding part of a treatise on noise - nue, New York, N. Y. The list follows: No. 240. reducing antennas, with good, practical Jl- Information on the Cornish Wire Com- for of pany "Noise- Master" Antenna Kit. Free. information the benefit the service- J2- Booklet describing the technical features men who install them. of the Hallicrafters' "Super-Skyrider" short- NATIONAL wave superheterodyne. Free. A Four -Band Exciter, by J. Herbert Hol- J3 -New 1935 catalog of the Hammarlund lister. QST, June, 1935. Instant band Manufacturing Co. Free. RECEIVERS J4- Resistor catalog of Electrad, Inc. Free. changing with circuit _ switching and fixed J5- Booklet on tube testing prepared by Su- tuning ; a good unit for advanced trans- preme Instruments Corp. Free. mitting amateur. J6- "Practical Mechanics of Radio Service," issued by F. L. Sprayberry. Free. Reports of the Radio Research Board, J7 -New 1935 parts catalog of Alden Prod- 10 gorso Council for Scientific and Industrial Re- ucts Co. Free. J8- Practical ham antenna design folder and COUPON , Int. search, Commonwealth of Australia. Ra- leaflet on a new auto -radio under car antenna dio engineers and students who find it system, published by Arthur H. Lynch, Inc. at¡onal chusetts profitable to follow the activities of brother Free. J9- Information on new radio courses given Malden, descriptive engineers in other parts of the world will by the Capitol Radio Engineering Institute. your entlemen me olo9Ue find much interesting reading in bulletins Free. G sandGenerol ° costs. of the Australian Radio Research Board, J10- "Radio Noises and Their Cure." A p1e°je 75 -page book. Price 50 cents. booklet b to cover . a government organization that seems to Jy2 -New parts catalog of Birnbach Radio cents . ' resemble our own Bureau of Standards. Company. Free. enclose Bulletins Nos. 87, 88 and 89 contain ar- Jy3 -Data on Vacuum Tube Voltmeter Meas- urements published by Clough -Brengle Com- Name ticles on such subject as the rotation of pany. Free. plane of polarization of long radio waves, J 4-"Increasing the Serviceman's Income," frequency recorders, the characteristics of folder issued by Philco Radio & Television Corp. Free. downcoming radio waves and long- distance Jy5- Transformer Bulletin of American Trans- observations of radio waves of medium former Corp. Free. frequencies. (Turn to page 180)

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Send only $2 with order. Pay balance (plus few cents for delivery) when it reaches you. Order Reg. 545 now, save 50% and own finest Installed in auto radio engineers can design. 30 Minutes BUYT-42 GUARANTEE WHOLESALE GUARANTEES (I) Its prices are wholesale, (2) Complete satisfaction. Send $2 bill, check or money- order. References; Dun - Bradstreet or any bank. ARD? ARD? ARD? FREENewl28Page Radio Book CONDUCTED BY GY Profusely illustrated, lots of data. 50,000 bargains! Receivers; Kits; Replacement Parts; Accessories; Tools; etc. Included with orders THE recent loss of the large TWA transport plane with a cargo of or sent alone-FREE! Use coupon below. human lives aboard has been traced indirectly to failure to get weather reports by radio. The investigation definitely placed the cause of the RIME. of 'ERVICc crash to weather conditions. To operate the radio communications equipment in the air service, the regulations at present only require the person IOO SIXTH AVENUE NEW YORK. N.Y. a third -class radiophone or license. Airline NEWARK. BRONx.N.Y so doing to hold telegraph 430VEREACNoeet stun 219 CENTRAL 542 E.RORDNAEA RO pilots are keenly aware of the fact that radio communications should not WHOLESALE RADIO SERVICE CO., it is are and Dep . RN 95, 100 6th Ave. N. Y. be part of their dotty, as when most needed they then busiest I will D I me e $2 for which send wee tube, Auto to it. solution DAY bal. plus few cents delivery chargea Seerh it toaRedio. unable to devote their entire attention Therefore, the only bend me your 128 page catalog FREE. to this problem is to employ on all transport planes complete equipment, Nam plus an able radioman to perform this service! Addr e se IN a recent issue of the ARTA appears employed by radio companies. Also, ship- a definite factual example of the vic- ping men have been informed that it is a tory which can be won through con- comparatively simple matter for them to certed and stick -together efforts on the obtain radio station licenses directly from part of radio men. The West Coast has the F.C.C. Therefore, as long as a radio been raised to the standards of wages and op performs his duties to the satisfaction conditions to which all radio operators of the shipping company, they will not MEASURING have aspired upon entrance into a field of have to fear the dismissals which were ELECTRICAL professional labors. Wage increases ranging practiced by radio companies because ops and RADIO from ten dollars to fifty dollars per man were not scaring up traffic for said outfits. have been won from shipping companies This is one huge step upward toward SERVICING INSTRUMENTS such as the Dollar Line, Pacific S.S. Com- proper conditions which are being fought pany and the American Mail Lines. for at the present time. new developments are now pro- Just to show. what a feller can do A new local office of the ARTA has just MANYgressing in the Triplett laboratories. towards keeping the oft -mentioned wolf recently been opened at Wilmington, Calif., Triplett engineers are concentrating on new from the doormat is the story of H. O. and from reports received "to see this ways and means to aid the serviceman in ob- Merriman of Ottawa, Canada, Chief of the office at 10 a.m., one would think that it taining quicker solutions to his testing problems. interference section of the Dominion of certainly must be the city editor's office of Canada. When he first started out it was one of the large daily newspapers, the way The Triplett line includes: with his total equipment strapped to his typewriters are pounding and phones ring- VOLTMETERS shoulders, earphones on his head and a ing and men to be interviewed." This office MILLIVOLTMETERS portable aerial in his hand. Mr. Merri- has taken over the reigns of the southern AMMETERS man's reports show that these man -made part of California and from its first MILLIAMMETERS disturbances are caused by almost every- showing is proving a great success. MICROAMMETERS thing, from a loose connection on an elec- There is great activity at the present due POWER LEVEL INDICATORS tric iron to electric light signs, street -car to the tanker strike which has about tied THERMO- COUPLE AMMETERS motors and elevator machinery. This ser- up this part of the coast and from latest OUTPUT METERS vice has been developed over a period of reports, twenty -two ops are on the beach, AC -DC METERS ten years, until now it has reached a coast - striking. This office also takes care of the RELAYS to -coast width with 32 trucks continually ops on the fishing fleet hereabouts and COMPLETE LINE OF TESTING moving. The U.S.A. is now starting its negotiations are in progress for agreements EQUIPMENT own campaign to do some tall eliminating. whereby the operator works on a base pay The ARTA N'Yoick Local advises that plus so much per ton for fishing. We Furnished in All Popular or Special Models the beach at this port and vicinity is understand that Simon Golden, the talka- and Ranges. pretty well crowded, although the Lakes tive one, is now out on the M.V. City of and a slight increase in shipping has re- San Francisco, a tuna fishing boat, work- See Your Jobber's Display Regularly duced the number some 60 or 70 men. ing under a part share arrangement. He Operators seeking assignments are advised would take this deal because his hunches that they may have to wait some two or are better than his figures. Write for catalog three months on the beach before getting There is always something new in this anything if they come to this port, as there old world and something new has been ELECTRICAL are many others ahead of them. Take developed out of all this strife -the "one - THE TRIPLETT heed! man" strike. Report has come in of such COMPANY Pacific steamship owners now realize a vase on the S.S. K. I. Luckenbach which INSTRUMENT idle for several hours. 170 Main Street Bluffton, Ohio, U. S. A. that radio ops are their employees and not held that vessel

www.americanradiohistory.com RADIO NEws FOR SEPTEMBER, 1935 179

After the op walked off the ship, other W1MG,- WJAEG,---W1AJZ (YL), - W1JK, ELEMENTARY MY DEAR union W1AFX, W1KZ,:^ W2NB, W2CTU, members followed and no cargo was TTW2HF, WATSON , 160T MY worked in or out of the holds. Quick work W4UPGftV4Uí\IHVS4AOPMW AXZFwSBMM, CLUE FROM RIDER'S by the local agent (of the shipping com- W8HTI, W8GY W8DLD, W8LUQ, W8L , pany at W9BEG NEW BOOK!" Seattle) settled the action tempo- W9BX ON ATII, CO2QZ, rarily, pending the official signing -of -an P6YD, VE4NI, VK3LRL. agreement. Rah, rah, rah, for this form, By Reginald Watson, The School House, as it doesn't take too Wraysbury, Staines, England, on 20 Meter much man power to phone: W1A\IG, WIDSY, W2DC, W2DE, accomplish the same thing. Highly scien- W2ALT, W2ZC, W2AMM, W2HFS, W2AN, 4 0 tific, what ! - - W2FLO, W2HAU, W3AE, W3HY, W3AVN, ati And só, me hearties, comes another dawn W3PC W3MD, W3AVN, W3BRG, W3EHY, IF Sherlock p o-d W4AHH, W4AH, and another day. Shipping companies con- W8GL1f W8DVU, W9BHT, Holmes were d W9EEL, VE1DV, CO2HY. a Serviceman to- stiFOe9? tinue to learn that an organization is only day, he wouldn't as good or as profitable as the morale of need a spy glass to discover that its men and a higher standard of living "The Cathode plus agreeable working conditions helps to Ray Tube at build it up greatly. They should remem- Work" is Rider's newest contribu- ber the plat 'that radio and radio ops play tion to servicing. when they are most needed and for this The Code Guild date we bring to memory the S.S. Olinda (Continued from page 149) This 320 page book on the theory and prac- of the Munson Line, tical applications of the Cathode Ray Tube which with five pas- W8FQS-Phili -McMunn, 29 Ramble Ave., bringe you right up to date on "dope" sengers and crew, caught fire at sea June Chautauqua, N. Y. needed to service modern equipment. Ex- 10th, 1913. In response to the radio SOS W8MHE-- Charles L. Gibson, 9 Sycamore periments in actual servicing work with the call, the U.S.S. Nashville St., Natrona, Pa. Cathode Ray Tube on amplifiers, P. A. went to her as- W8EEZ -Tauno M. Alanen, 512 New Street, equipment and "ham" x- mittere, were sistance and rescued all. And that brings Fair rt Harbor, Ohio. performed right in our own laboratory. us to the illustration in our heading this W8KGM -E. J. Goodison, 300 E. Edward St., month, for there is Endicott, N. Y. pictured two Bureau W9HHW- Denzel Begley, Box 46, Ft Meade, of Standards engineers at the controls of a S. Dak. SERVICING 1919 -1935 SETS fire -signal detector for shipboard which W9SFT- Gerald Broughton, CCC Co. 735, Rider's Trouble Shooters Manuals, 5000 pages of detects the presence of a flame up to 200 Scammon, Kansas. schematic illustrations and descriptive text, covers W9TE -A. L. Braun, 5211 Brookville Rd., 1919 to today, in volumes 1, 2, 3, 4, 5. No other man- feet away. Maybe here's a chance for Indianapolis, Indiana. uals contain so many manufacturer, models, I.F. additional operators, as in all probability W9LKK- Sidney Schulz, 3132 -4th St. S. E. peaks, chassis views, voltage data, resistance values, this device and its control panel will come Minneapolis, Minn. etc. Remember -no duplication of material in any W9LS-U Clarence Read, 3401 Parnell Ave., of the 5 volumes! under their jurisdiction. So with this to Chicago. sleep on ge 73 GY. Keep your manuals up -to -date! Riders ...... house organ "Successful Servicing" keeps you informed of all additions and changes, free of charge. Write for your copy today to Dept. RN95. The Valentine Super JOHN F. RIDER Radio in the C.C.C. (Continued from page 145) PUBLISHER (Continued from page 164) ode is another condenser of such value keynote of the educational program in the that a measure of bass compensation is C. C. C. is vocational study. obtained when the slider is near to the In those camps that have official stations, the grounded end 1440 BROADWAY woodsmen -students want to operate that station. of the resistance, or low NEW TOUR For "Sparks" is a big man ... new C. C. C. volume position, without undue attenuation rulings have provided an exemption for the of the higher frequencies when greater radio operators from mandatory discharge after volume is desired. Automatic volume 15 months' service. And for the average C. C. C. con- man, such a status is a goal worth attaining. trol voltage is obtained from the high end of the potentiometer and is filtered by means of a 2 meg. resistor and .1 mfd. condenser. This voltage is available at pne pole of the "a.v.c.-No a.v.c." switch, the The Ham Shack other pole being connected to the various a.v.c. filters in the grid returns of con- (Continued from page 149) trolled tubes. The blade of the switch is Heard grounded. Audio frequencies pass to the Calls grid of the 56 audio amplifier through a By Edwin Hoover, 1819 East Fifty-fifth Street, .02 mfd. mica condenser. Filtration is em- Cleveland, Ohio, on 20 meter 'phone: CO2HY, ployed in CO2KC, CO2LL, CO2WZ, CO7HF, HHSPA, the grid circuit of this tube also, HI7G, HP1A, K4SA VEIDR. VE4LA, and grid bias provided by a resistor in VESHN, W1AVG, W2A5J, W2BCP, W2BYP, the cathode leg, its value depending upon W2CLA, W2CRB, W2CZO, W2DYR, W2EUI, W2HFS, W2MO, W3ACX, W3AIF, W3BBO, the method of coupling to the amplifier. W3BIH, W3BPH, W3CIJ, W3MD, W4ABG, A noise control consisting of a 1 meg. W4AGP, W4AGR, W4AH, W4AHH, W4ALG, rheostat and series .02 mfd. condenser is Metal -Can W4AUP, W4BFB, W4CJ, W4FK, W4HX, W4PI, W4QZ, W5AAQ, WSAEB, WSAFX, connected from plate to ground. Though WSAHD, WSALI, WSAMS, WSAMZ, WSAOO, somewhat beyond the scope of this article, ELECTROLYTICS WSAOT, W5AVM, WSAXA, WSAXU, W5AYF, the primary purpose of which has been W5BAT, WSBDB, WSBDG, WSBEB, WSBEE, For maximum capacity in minimum bulk, low- W5BEQ, WSBFS, W5BGT, W5BIN, W5BMM, to describe the V-8 tuner, a circuit diagram is given of the est first and last cost, trouble -free operation, WSBOP, W5BVH, W5BYJ, W5CAE, WSCEO, amplifier and power complete satisfaction- nothing excelle AERO- WSCTC, WSCUA, WSCV WSCYI, WSDCO, supplies used by the author. (Figure 1.) WSDCP, WSDDP, WSDN7, WSDQ, WSDUF, VOX metal -can electrolytics, featuring: WSEBP W5ECL, WSEFV, W5EPR WSEUB, The parallel feed choke in the plate of the W5EVV, W5FJ WSHJ, W5IT, WSLi1, WSNF, 59 triode combined with the .5 mfd. coup- Largest line ... variety Special composition spac- W50X, W5PP,VSSF W5SH, WSUN WSZA, ling condenser were chosen to favor re- of cans ... all voltages, ers, therefore surgepraof W6AVU, W6BAY, V6BFP, capacities, combinations. all- aluminum parts. WSZS, W6AM, sponse therefore non -corroding. W6CIN, W6CLL, W6CQG, W6DA, W6DCQ, to frequencies in the neighborhood Hermetically- sealed . W6DEP, W6DJJ, W6DL1, W6DMN, W6DTX, of 4500 cycles. The use of fixed bias on Longest service life W6EIP, W6E9J W6ERT, W6FCL, W6FFN, the 59 driver and 45 no leakage, seepage. ab- freedom from breakdown tubes, used Class A sorption . absolutely W6GOY, W6HLY, W6HOE, W6TYH, W6JZH, prime, more than liberal W6KM. WfLR, W6WP, W6H. W7AIT, allows of obtaining high output and trouble -proof. safety factors. W7ALZ, W77A0, W7ARK, W7BCI, W7BCU, adapts the amplifier to handle the very W7CAI., W7CFX, W7CHT, W8BNC, W8BRB, healthy signals supplied by the tuner. To New 1935 catalog contains many pages \V8BUD, W8DI, W8DLD, W8EFW, W8FHE, featuring electrolytics for initial and prevent feed -back both tuner and ampli- DATA replacement purposes. Send for your W8FJP, W8FSS, W8HFE, W8HIH, W8IMU, copy-also sample copy W8JAI W8KC, W8KJE, W8LIR, W9AE, fier are mounted on sponge rubber cush- of Research Worker. W9AGÓ, W9ANZ, W9BBS, W9BCX, W9BE , ions, and the speaker baffle is similarly W9BJ, W9BPK, W9BPM, W9CET, W9C1J, \V9CUH, W9CVN, W9DGM, W9DMF, insulated from the bounding walls of the W9EEL, W9EL, W9FDO. W9FSO, W9FWJ, cabinet. \V9FYP, W9GHI, W9GHY, W9HQT, W9IM , In conclusion, the author makes no W9JEH, W9JNG, W9JRY, W9K A, W9KGR, claims for W9LD, W9LGT, W9LNB, W9OLG W9OMM, extravagant this tuner, but does W9OZK, W9PDI, W9PEP, W9PIf, W9PJQ, say that from his own experience, and W9PV, W9RTQ, W9SBJ, W9YL, X1G, X1W, from that of others who have built it, CORPORATION X2AH. results justify what By W. A. Cantrell, 503 East Prescot Road, may appear to be 78 Washington St. Brooklyn, N. Y. Liverpool, 14, England, on 20 meter 'phone: somewhat unusual methods of construction.

www.americanradiohistory.com 180 RADIO NEWS FOR SEPTEMBER, 1935 METAL RADIO TUBES! RADIO PHYSICS COURSE National Union gives ALFRED A. GHIRARDI Service- Dealers new Lesson 44. Impedance ing from the sine -curve variations of alter- testers to test them. nating e.m.f.'s and currents. Such a tri- IN practical circuits in which there exists angle is very frequently used to represent not only inductance but resistance also, the relations between resistance, reactance, Send coupon for details! it is necessary to know not only how to and impedance and also for convenience in calculate inductive reactances but also how obtaining other quantities. It is called a to combine reactance with resistance. The vector diagram. Another way of looking combined effect of all the reactance and all at this, is that since the voltage drop across the resistance in a circuit is called the the resistance is in phase with the current, impedance. This is represented by the and the e.m.f. of self -induction is 90 de- symbol Z. The impedance represents the grees out of phase with the current, resis- total opposition to the current flow in an tance and reactance are really like two alternating- current circuit offered by both forces at right angles to each other; and

the actual ohmic resistance, and the , ap- the common principle of the parallelogram , parent resistance or opposition due to the of forces which is applied for solving prob- counter- e.m.f. of self- induction (and ca- lems involving forces in mechanics, can be New pacity as we shall see later). The applied applied to them. All Metal alternating e.m.f. has to send current or When the inductive reactance is small Radio Tube electrons through the circuit against this compared with the resistance, as shown at Type 6C5 total impedance in the circuit. The im- (C), it has very little effect. The line BC Actual pedance in ohms of any alternating- current is short compared with AB, and the im- Size circuit is expressed by the formula: pedance line AC is not much larger than AB. the resistance is kept resistance? the resistance If Impedance -V + reactance' reactance is doubled, or If the circuit contains resistance and in- the same and the 2 the impedance AC1 ductance only (no capacitance), this may BC' equals X BC, is very much increased over its former be expressed as value AC. When the reactance is very Z= ß/R2 + XL' orZ - VR2+ (23 fL)2 large compared to the ohmic resistance, as The relations expressed by the above for- shown at (D), the impedance AC is very Book- Cathode Ray Oscillograph NEW! mula may be represented by the right - much greater than the resistance AB. This in Service Work. Send 15c. angled triangle ABC shown at (B) of Fig - important fact should be remembered, for National Union Radio Corporation of N. Y. ure 1. At (A) is shown the circuit condi- it is one of the reasons for making the in- 570 Lexington Ave., New York City RN935 tion of a resistor connected in series with ductance and inductive reactance of a tuned Tell me about new testers for all metal an inductor. In (B) the true ohmic resis- circuit as large as practical in order to radio tubes. tance R is laid off to a convenient scale obtain high gain. Name to form the base line ; the reactance X is In inductors where the inductance is very Street laid off also in ohms to form the perpen- large compared to the ohmic resistance, the dicular; and the impedance in ohms is resistance may often be entirely neglected, City State found by measuring the hypotenuse of the and the total impedance of the coil may be triangle (to scale), since the hypotenuse considered as being due wholly to its in-

AMERTRAN C TRANSFORMERS ti C XL For Quality Amplification XL B A B RESISTANCE R (A) (B) FIGA (C) (D)

Figure 1. rector relations of resistance, reactance and impedance in an inductive circuit.

of any right -angle triangle is equal to the ductive reactance. If the frequency is square root of the sum of the squares of doubled in such cases, the reactance is also

the other two sides. This is merely a doubled . and the current at the same ap- mathematical coincidence, however, result- plied e.m.f. is reduced to one -half. THE MOST COMPLETE SELECTION AVAILABLE The Technical Review ters of this station will be HP50 and it This bulletin contains the will work on a frequency of 1440 kilo- Booklet Service) cycles. Another new station, which will, most complete listing avail- (Free be known as HP53 will be installed by Sr. able of transformers and re- (Continued from page 177) Simon Vega at Bocas del Toro, Panama. actors for audio amplifica- This station will operate on a frequency Al- Information on new Browning "35" re- tion and transmission. It ceiver, issued by Tobe Deutschmann Corp. of 9565 kilocycles. fully describes and illus- Free. A2 -New parts catalog of Wholesale Radio trates five complete lines, Service Company, Inc. Free. "Normandie" Standard DeLuxe, Mini- A3 -Data on a multi- testing instrument, The the published by Supreme Instruments Corp. Free. ature DeLuxe, Precision A4- Condenser catalog prepared by Cornell. (Continued from page 141) DeLuxe, SilCor and trans- Dubilier Corp. Free. lines. Standard A5- Instructive and interesting information ratus, enabling passengers to converse with mitting on condensers published by the Sprague Prod- land -telephone subscribers in France, England types are offered for every ucts Company. Free. and the U. S. A., is contained in this room. and in three The transmitting unit of the radio -telephone requirement equipment is designed so it can be used in con- different price classes. New Stations for Panama nection with radio broadcasting work whenever upon to serve CBS Ask for Bulletin 1002B desired. And it was called PANAMA CITY, PANAMA -The gov- and NBC chains, daily, during the maiden voy- AMERICAN TRANSFORMER y age. Both networks had crews on board to ernment has authorized Senor Jose Jaen handle the broadcasting from the ship. Alfred COMPANY Jaen to install a radio broadcasting sta- H. Morton, NBC program manager, and Paul in the city of Colon. The call let- W. White, CBS director of special event broad- 177 EMMET ST. NEWARK, N. J. tion

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 181 casts, headed their respective network staffs frequency where L and C are in resonance, consisting of an announcer and an engineer. NEW!- A practical book to The departure from Le Havre, ship concerts, the formula becomes: 2 help you pass examina- interviews with passengers and the arrival in /( 1 1 New York tions for all classes of were among the program subjects Z = V radio operator licenses. of the voyage. t\ R C2w2 The radio -telephone transmitter has a power RL C2w2 Planned Especially of 1 to 1% k.w. in the antenna, depending on The value for Z approaches infinity as the wave emitted. It has eight available waves for Home Study between 17 and 70 meters. The radio-telephone RL approaches zero, which is the case for Here is the book for the ex- receiver is in a special shielded cabin, inde- any anti -resonant circuit of this type. perienced operator or station technician w o wants to advance to a better job, pendent of the commercial cabin. Compart- One of the advantages of the complex It is equally suited for the man just entering thic ments adjacent to tfie commercial cabin contain field, who wants to take up essential, authoritative current distribution apparatus and storage bat- form of notation is that it enables us to preparation for a license in any branch of practical teries. start with any type of network and reduce radio operating. The bridge radio equipment includes trans- it to one impedance (for any frequency) Just Published mission and reception apparatus for use in actual before making any numerical substitutions. navigation work. In addition there is a radio direction finder and a "sounding" device. On the other hand, we can transfer the Two motor lifeboats contain storage -battery complex notation into a vector diagram PRACTICAL RADIO radio distress signalling apparatus. The trans- at any point along the line. mitters in the lifeboats are of the spark type. COMMUNICATION Six antennas are especially located to permit The general formula for the relation simultaneous operation of two transmitters with between current, voltage and impedance 744 pages, 4x7, over 400 illustrations, $5.00 the duplex facility of coinciding reception. is frequently written By Nikon and Hornung, well -known radio experts, A novel international broadcast stunt in which instructors, writers. This book covers the require- the Normandie figured took place when the ship E = IZ ments for ALL CLASSES of radio operator's license steamed up New York Harbor for the first time. This always applies to any circuit or any examinations, treats long, medium, short, and NBC and the General Electric Company ar ultra -short wave radio,, includes ALL CLASSES part of a circuit, provided we remember of radio stations -is in general a complete text on ranged for Washington officials to greet the ship practical radio communication based on a theo- by a "talking light beam ". Land lines conveyed that it is a complex formula, and all three retical introduction. the greetings from Washington to the torch of of these quantities must be treated as such. the Statue of Liberty where the voices were (In our next installment we will use this What this book gives you converted into light to pulsations of directed to show when why impedance -full treatment radio. and electrical principles: delves the ship by a powerful reflector. A large con- data and deeply into alternating currents. cave mirror on the Normandie picked up the light matching is a requirement for distortion - -particular attention to broadcasting; Western Elec. rays and converged them on a photo -electric less transmission.) trie broadcast transmitter; studio acoustics and ap- cell to convert the light waves into paratus, control -room equipment and operation back sound. special diagrams, etc. The voices were sent from shipboard to Radio section on ultra-short-wave equipments, for police op- City by short waves and thence by landline to - erators. W2XAF, Schenectady, which relayed the pro- -radio -telegraphic and radio-telephonic treatment gram to France. aviation radio; aircraft transmitters, receivers, direc- The debut of the Normandie, its tion- finding equipment; testing and maintenance. and extensive Dots and Dashes -marine medium- frequency equipment, high -frequency radio layout indicated that the world's largest transmitters and receivers; Coast Guard low -power liner will continue to be a constant source of (Continued from page 135) transmitters; direction -finders, etc. interesting program fare to both the broadcast -power -supply apparatus; rectifiers; generators; batter-

- ies, etc. listener and the short -wave fan. - Many other helpful facts given. Clear, concise, of each system. Farnsworth's West Coast well-illustrated style. New features of arrange- B. McCargar, is said to be ment. Complete, practical, authoritative. Use backer, J. this plete, anxious to see Farnsworth's ideas in opera- get ahead in radio operating. tion in America as well as in Europe. See it for 10 days without obligation

Establishing Television in SEND THIS McGRAW -HILL ON- APPROVAL Impedance Match COUPON Holland McGraw -Hill Book Co., Inc., 330 W. 4'tnd St. N. Y. C. (Continued from page 155) EINDHOVEN, HOLLAND Experi- Send me Nilson and Hornung's Practical Radio - Communication for 10 days' examination on ap- menting with television on a larger scale proval. In 10 days 1 will send $5.00, plus few cents postage, or return book postpaid. (Postage paid on than heretofore, Philips Lamps, Ltd., of orders acfompanied by remittance.) 3. For both branches in parallel: this city, will establish a test transmitter 1 Name operating on a wavelength of about 7 Zb = meters. The new station will be located Address 1 1 City and here. A 3 -meter transmitter hás been used State + by the Holland radio firm for some time. Position RL -I-jwL -j The company has emphasized that while Company RN -9 -35 considérable laboratory progress has been (Books sent on approval in U. S. and Canada only.) wC made, there will be no practical television Adding the fractions and simplifying, this service for the general public immediately. expression becomes It is understood that Philips has developed RL REPLACEMENTS FOR -}-jwL a television receiver yielding a projected Zb = picture of unusual sharpness and bright- ALL REGULATORS OR. (1- Lw2C) -I- j RL w C ness. Now we must separate the j terms from BALLAST TUBES those not containing j. This can be done A New Belgian Television if we can get rid of the j in the denomi- System? . Tanaaralze Hmperlre nator.. When the denominator is the sum Regulators. ¡I-here's an of two terms, one which contains j, we can BRUSSELS, BELGIUM -Leon Damas, Amperite for every cur- eliminate j by multiplying both numerator a young radio engineer of Charleroi who rent or voltage problem has occupied himself with television prob- and denominator by the difference of these . . . . in any set. terms. In this case, therefore, we multi- lems for the last few years invented a new ply by' system of television, it is reported. The Write for CHART CV. [(1- Lw2C)- jRLWC] new system permits the transmission of After doing this, and collecting terms, we image and sound on the same wavelength /414MPERITE have the final expression for the impedance in complete synchronism, it is reported. CURRENT AND VOLTAGE of the branched part of the circuit. To Moreover, it is said that Damas has suc- this we add R, which is in series with the ceeded in transmitting television images in REGULATORS branched part. Finally, then, we have natural colors. The young inventor was the 561 eaonownv N!w complete expression for the impedance of aided in his work by Prof. Baethelmans MPER/TECO. the circuit. of the Jesuit College at Charleroi. RL Z = R -{- -}- A New Tuning Indicator (1 - Lw2C) 2 +RL2C2w2 NEW YORK, N. Y. -A new tube, Resistive part designated 6E5, which is designed as a Lw(1- LCw2) RL °Cs, visual tuning indicator, has recently been little- giant - announced by the RCA Manufacturing ULTRA- COMPACT j (4) ELECTROLYTIC CAPACITOR (1 Lw2C)2 + RL2C2w2 Co. The tube has a fluorescent target - located in the dome of the bulb. When Half Cornier sizes -full capacity- ' full voltage protection! Minimum Reactive part the tube is in operation this target becomes thickness means they fit anywhere. Now, if the impedance for a specific set luminous and shows a circle of light. A Use this latest advance in the eke- ; trolytic art! of conditions is required, we must substi- sector of this circle will remain dark, the tute the numerical values in Send for literature. formula (4). angle of the sector depending on the bias All Usual Capacities in 2 ratings

Often in substitutions we find . that some on one of the elements of the tube. The -450 v.w. and 200 v.w. of the terms become negligibly small and shaded angle will vary from 90 degrees to SOLAR MFG. CORP. can be dropped out. For example, at a (Turn to page 192) 599 -601 Broadway, NewYorkCity

www.americanradiohistory.com 182 RADIO NEWS FOR SEPTEMBER, 1935 TRY THIS NEW SPEAKER ASSEMBLY FIND out for 5 DAYS The yourself about tremendously increased FREE measure of R4D1-0 performance, adaptability and good ap- .pearance em- bodied in this amazing new WORKSHOP outfitforevery in- doorrequirement. All- aluminum baffle housing, adjustable wall mounting bracket, improved speaker efficiency with feed -back practically eliminated. Like all Toledo equipment Items of interest for beginners, ex- it is dependable first, last and all the perimenters and radio constructors. time. Write for catalog, prices and data 41 on the laboratory-built TOLEDO line. Learn about our liberal free 5 -day trial. Handy Tool tightened in the vise in a vertical position, A and the chassis held in place over it by a OTHER TOLEDO PRODUCTS The cutting of tube -socket holes or any single clamp, as shown. The drilling is prob- Portable Sound Systems Electro- large size cut -out in a metal chassis pressure was then applied against the heavy job in home Dynamic Units Carbon Micro- ably the most troublesome wood, which in turn was solidly supported construction. It is difficult only by the vise. The chassis remained perfectly phones Amplifiers 4, 5 radio-set and because so few radio constructors are fa- fixed and the holes were made in quick 6 Ft. All Aluminum Natural - miliar with the proper tool for that pur- order. tone Trumpets Field pose and the proper means of supporting The same set -up was used in cutting Exciters Air Column the chassis itself, during the drilling oper- holes in the short sides of the chassis. In Horns Low and ation. this case the clamp was merely turned High Frequency The tool for the job is a very simple and around so that the handle was out of the Units For Wide inexpensive device called a circle cutter way of the long arm of the circle cutter. hand brace. Range Theatre Use which fits in any standard In cutting 2- and 3 -inch holes in panels While three sizes are available it is only for meters, it is advisable to use a scrap TOLEDO SOUND EQUIPMENT LABORATORIES necessary to possess the medium size model, piece of board as a backing in the vise. Formerly Bud Speaker Co. (costing a little more than a dollar) for This will prevent the panel from buckling 1140 JACKSON STREET TOLEDO, OHIO, U. S. A. radio construction work. This size is cap- under the pressure of the brace. To avoid able of cutting holes from 1 to 4 inches clamp marks, place bits of hard wood un- in diameter in aluminum, steel, bakelite, der the feet of the clamp and tighten the hard rubber and wood. latter carefully. laboriously made Mr. E. H. Rietzke, Presi- To anyone who has ROBERT HERTZBERG, dent of CREI and originator socket holes with a small drill, a cold chisel New York City. of the first thorough course in Practical Radio Engineering. and a file, the circle cutter will be an absolute revelation. Holes that previously took Simple Battery Connector GOOD 15 or 20 minutes can now be made in 15 A practical and time saving connector ... or 20 seconds, and furthermore, they are for either A or B dry batteries or any really round! type of apparatus having knurled nut ter- INTENTIONS won't As the cutting tool of the cutter takes minal connections, can be made from grid - a healthy bite out of the metal chassis, control clips, as used on screen -grid type get you a GOOD JOB! the latter must be braced securely so that tubes. there is no possibility of twisting and the You have be "Technically Quali- to best aid for this is a large husky vise, but fied" - to get anywhere in Radio today. This fast -growing industry demands a small one is satisfactory if it is supple- that the good jobs go only to tech- mented by some short pieces of 2 by 4 nically trained men. Your "good in- wood blocks and a couple of ten -cent C tentions" aren't enough ... right now clamps. The accompanying illustration is the time 'to start studying, for shows how a 12 inch steel chassis was Radio executives recognize the superi- handled in a vise having only 2/ -inch of CREI men ority and ability jaws. A 6 -inch stub of a 2 by 4 was first and your CREI Diploma is the best reference for a good job. LEARN More and EARN More! CREI training gives you the "tools" with which you can build your own future. The many CREI men who The three leaves of the clip are bent are now holding important engineer- is ing jobs prove that Success comes together so that when the clip pressed with Knowledge! on the knurled nut terminal it will grip it firmly. If this is done properly the clip 3 PLANS OF STUDY TO SELECT! becomes a quick change positive contact 1. Study in Washington under and shakeproof connector. trained instructors. STEVEN S. ERICKsoN, 2. Study at home under the personal Evanston, Ill. direction of an instructor. 3. Study by a combination of both Simple Idea for Suspending methods. Separate Speaker on Request! Free Catalog The separate loud speaker employed with types of short -wave sets is ENGINEERING INST. many popular CAPITOL RADIO something of a nuisance if placed on the Dept. R. N. 9 operating table, particularly so if the set 14th and Park Road- uses plug -in coils. Washington. D. C. A good stunt is to hang the speaker from the ceiling just far enough above the table to clear all apparatus. In the cellar or

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 183

more accurate results than a home -made substitute. Also, you can change dials as often as you wish when experimenting, without the expense of a new dial. C. G. GROVER, Salt Lake City, Utah. (Turn to page 188)

What's New in Radio (Continued from page 175) ente caused by reflection, feed -back, audience noise, etc. If desired the instrument can be changed from uni -directional to teer non -directional, instantly and at will. Centralab When it's tough sailing, Skipper attic radio "shack" this is the work of only A "CQ" Key Serviceman, be nonchalant . . . a few minutes. Some odd lengths of aerial steer by Centralab. wire and a few screw eyes are all that are (Continued from page 147) For Centralab Controls are needed. built to "take it" in all kinds of The speaker should be inclined inches in diameter, cut out with a com- weather . under all sorts of down- mon fly- ward a little so that the sound is directly cutter. The dots and dashes were adverse conditions. It's smooth in line with the operator. Incidentally, laid out on paper with a ratio of 1:3, the sailing under sunny skies if you removing the loud speaker from the oper- spaces between letters being somewhat stock up with CENTRALAB greater than length ating table seems to eliminate slight micro - the of a dash. This Radiohms for each and every re- phonic effects, previously present. space was doubled between words. The placement job, which invariably space between parts of a letter is the most work "better than ever before." ROBERT HERTZBERG, difficult to judge, depending upon the Smooth, silent, safe, sure and cer- New York City. rider. At first, a space equal in length to tain ... no wonder they are the Home -Made Radio Cement a dot was tried, but this was insufficient, choice of servicemen who "are in a lot of filing being necessary. A dot -and- the know." A good grade of radio cement can be -a -half length may be sufficient, but two - Write or see your jobber for easily made at a small cost from acetone dot length is recommended. Then the the new, revised, accurate celluloid. CENTRALAB VOLUME and Experimenters and service- rider will not have to be bent almost to a CONTROL GUIDE. men will find a cement of this kind ex- right angle but can be straightened out tremely handy for cementing speaker cones, somewhat to a "smoother" angle. If befit Centralab insulating coils, repairing tube bases, etc. too sharp, the action is "pecky" causing a Division of Globe -Union Mfg. Co. A small amount of acetone and a few chatter. A smooth and even action is, of Milwaukee. Wis. strips of celluloid may be procured from course, desirable. When the characters are Orry Srrrirc ti/ any drug store. Next obtain a small bottle proportioned on paper the design is trans- h atdb.a.ne,aerq,he watn.u..., Alm with a brush attached to the cap. A dis- ferred to the disc. Clamping the disc in a carded bottle formerly used for fingernail vice, the "roughing" is done with a hack- polish answers the purpose very nicely. saw and the job is filed clean with a jew- The celluloid strips are dropped into the elers' file. Two files, coarse and fine, will acetone, where they slowly dissolve to form save a lot of time. Two blades "in paral- the cement. If the cement becomes too lel" in the hack -saw will also save time. RADIOHM thick, simply add more acetone; if too The job is simple and interesting and thin, add more celluloid. should not take over a few hours. A second Jos. S. NAPORA, disc will, of course, go much faster. For IMPROVE Uniontown, Pa. mounting, the center hole is tapped for a your S.W. re- Replacement Dial 6 -32 screw and a lock nut employed. ception with The contact pieces are mounted on PEAK Prod- It is not necessary to replace the dial on brass angles which are fastened by one of ucts. a small meter when its range is changed, the original gear -box screws. They must The Peak P -11 is as for a revamped testing instrument, if the be insulated from the box and from each the only Pre -se- new range requires the same number of other, of course, the amount and type lector guaranteed of to give uncondi- dial divisions. insulating depending upon the voltage in tional satisfac- Cut out a round piece of heavy draw- the keying circuit. The breaking of plate tion to the most ing paper or Bristol board the same size voltages over a few hundred volts is critical S.W. list- not eners. and shape as the old meter dial. An arc recommended. A relay should then be is then cut out of the new dial as shown, used. P E A K so that when placed over the original A standard size 2- or 4 -ohm rheostat meter' dial it leaves the original scale divi- will control the speed of the motor. The R E G E N E R A T I V E sions visible. Then the numbers for the motor may run satisfactorily on 4 volts P R E - S E L E C T O R new ranges can be placed on the without a rheostat. paper Tremendous increase in signal strength. Absolute dial with India ink. By using this method, rejection of image. Increased selectivity. Decrease the original meter scale is retained, giving of noise level to signal ratio. PEAK Q -5-the last word in design of Ultra H1gh Frequency Super Het receivers. PEAK X -4 10 watt 5 meter x- mitter. A quality Backstage transmitter at a price within the reach of all, now available. (Continued page For further data on PEAK Products see your dealer from 171) or write to Dept. A. long tour a national "open" radio tourna- EASTERN RADIO SPECIALTY CO. ment was arranged to bring new talent to Mfrs. of PEAK PRODUCTS the mike. The plan was to conduct the 1845 Broadway New York, N. Y. auditions in each city of the tour and bring the best man and woman of each locality RADIO CODE to the Tuesday night broadcast. A cash is easy to learn when you have your award accompanied each microphone ap- own Instructograph. with each machine sold or rented. comes Book of pearance. After national eliminations, four Instructions showing how to study to finalists were to be brought to New best advantage. Regular practice with York this equipment is all y.nt need to be- for the awarding of grand prizes. Profes- come a real operator. Write for full sional and amateur singers were permitted details. INSTRUCTOORAPN COMPANY Dept. NR-9 in the auditions, as, of course, the word 912 Lakeside Place Chicago, III. Representation for Canada Toronto "open" implied. Radio Collega of Canada,Ltd 863 Bay St.

www.americanradiohistory.com 184 RADIO NEWS FOR . SEPTEMBER, 1935

European BC have been erratic and with The DX Corner the exception of Rome on 713 kc., which has -BUILD been heard fairly regular, only the more powerful ones have been picked up, and these at about THE NEW GEN -RAL (Broadcast Band) R3 -R4." Observer Tucker (Alaska) : "Received my (Continued from page 167) L.P.O. appointment. It took 50 days to reach SUPER DX -8 me in the mails. Reception this spring has been fair with California stations coming in at 8 to PROFESSIONAL S.W. SET p.m., C.S.T., Daily; WHIS, 7 -9, 12 -3, and 6 -8 p.m. E.S.T.; Daily; WHBQ, 7:30 a.m. -10:30 9.p.m., the best of which were KFI, KPO, KGO p.m. C.S.T., Daily and 1:30 -2 a.m., Wednes- and KNX. days except first Wednesday of the month. "The transpacific stations are heard best be- Would like very much to correspond with any tween 10 and 11:30 p.m. The best of these are foreign readers of the DX Corner." 2YA, 570 kc.; 5CK, 635 kc.; 1YA, 650 kc.; 3YA, 720 kc.; 800 kc.; 3ZR, 940 kc.; 4BH, Observer Nichols (Connecticut) : "Station 3L0, KRNT, 1320, Des Moines, Iowa, can be caught 1380 kc.; KGU, 750 kc.; KGMB, 1320 kc." as they sign off after CBS chain program, at Observer Prats (Puerto Rico) : `Static is 1:00 a.m. E.S.T. every night, as they prac- somewhat improved but is still bad enough to pre- tically always give some little item with their vent reception of about two -thirds of the stations sign off, time, etc., that can be used to verify normally heard during the good season. Sta- tions now being heard (letter dated June 26th) Beat them." Wired R.F. Unit Oscillator Observer Kentzel (New York) : "CMBX, are: WJZ, WEAF, WLW, WABC, WHAS, Full A.V.C. Pre-selector 1380, Havana, Cuba, announces that they are on WWL, WLS, WENR, XEAW, WCAU, True Electrical Bandspread the air every Sunday between 1:30 and 6:00 a.m. YV1RC, WBZ, KYW, WTAM, KSL, WOAI." E.S.T. with a DX program." Send for Circuit Observer Elcheshen (Ohio) : "I totalled up the mileage of all the stations I have received. FREE Diagram and Parts List For instance. Chicago-airline distance 303 miles, Cuba -1360 miles, etc. Well! here are the The Service Bench results - Alliedk Radio B. C. B. 618,767 (Continued from page 173) CORPORATION S. W. 106,651 Police 24,054 833 W. JACKSON BLVD., CHICAGO Amateur phone 1,309,095 dary, and the conventional tube rectification circuit substituted. (In some in- Send me FREE Diagram and Parts List Miles total 2,508,567" stances, a slight readjustment of voltages for building the Gen-ral Super DX -8. Observer Wilson (Virginia) : "My receiving may be necessary.) equipment has changed to an RCA -Victor `Magic Brain' all -wave receiver, model 281 (12 tubes). "Upon completion of the alteration the Name. Perhaps this fall and winter, I shall be able to set operated with full efficiency. The cost send you some good lists of distant stations heard of the job was about one quarter that of a on this new receiver." Address I Observer Parfitt (Virginia) reports 248 sta- new vibrator unit." A. W. Tytler, Jr., tions heard since the first of the year with 231 and L. L. Hotsenpiller, Roanoke Radio verified. The 15 -watt KFPM, Greenville, Texas, Service, Kansas City, Mo. is one of his best catches. He offers the following tips: "WSVA, 550 kc., regular schedule 7:00 COLLEGE a.m. to 5:30 p.m. or sometimes till 6:00 p.m. Test for Hum Degree in 2 Years E.S.T. WOPI, 1500 kc., from 7:00 a.m. to 9:30 p.m. E.S.T. weekly and 10:30 a.m. to 9:30 p.m. George Miers, of Miers' Radio Shop, Complete Radio En- Sundays. WILM, 1420 kc., is on every week- Easton, Pa., immediately suspects the elec- gineering course in 96 day morning at 7:00 a.m. E.D.S.T. WDBJ, trolytic condensers in cases of hum in re- 1 hour and comes on now weeks. Bachelor of 930 kc., has moved up ceivers employing this type of capacitor. Degree. Radio at 7:00 E.S.T. Anyone needing KGA, 1470 Science kc., can get them most any night after 2:00 a.m. He suggests tipping the receiver on its side, (television, talking pic- They sure are consistent." tures and the vast E.S.T. while in operation, and note any change Observer Robinson (Nova Scotia) : "LS2, electronic field) offers unusual opportunities for Radio Prieto, 1190 kc., Buenos Aires, Argentina, in the hum intensity. If it decreases, it is trained radio engineers. Courses also. in Civil, has been heard as loud as R7 -8 fairly consistently a definite sign of a faulty electrolytic con- Electrical, Mechanical, Chemical, Aeronautical, lately from a little after sundown until WOAI denser. Architectural Engineering; Business Administra- overrides them. CMQ can be heard nightly after tion and Accounting. Low tuition, low living costs. CRCT signs off on 840 kc. Have a veri from World famous for technical two -year courses. Those "mystery; DX" station mentioned in July R. N. SERVICE NOTES who lack high school may make up work. Students He was an amateur on 990 kc. so couldn't ad- from all parts of the world. Located in picturesque vertise name. Between 9:30 and 10 p.m., A.S.T. The Radio Manufacturers Service has hill and lake region of northern Indiana. Enter on July 25th, heard LS2, 1190; LR9, 1030; LR3, arrived at an agreement with the Western September, January, March, June. Write for catalog. 950; LR6, 870; LRS, 830, all cording in fair to Telegraph Company, whereby good. LR8 spoiling WHAM. LS8 spoiling Union any- 1695 COLLEGE AVE. ANGOLA, IND. WNAC, ZP9 good sometimes on 890 kc. Span- one in need of radio service need merely iard on 1140 good. (static R8.)" call Western Union to secure the expedi- Observer Bohm (Sweden) : "DX reception tious attention of an R. M. S. has been bad during the last months. There member. Sensational Value! are no U. S. stations audible, only some South The cost to the serviceman is only. 10 cents Americans, LR2, LR3, LR4, LR5, LR6 and per service call obtained in this way, and "DEPENDABLE" LS8. Those Argentineans are best received from to the customer, the price of the telephone 1:30 -3:30 a.m. Middle European Time. The best TUBE- TESTER U. S'. station during the last DX season was call plus the usual radio repair. charges. KOA of Denver, Colorado. Many times I heard Expert servicemen who are interested, and EWEST tube, resist- New N this station with R8, on nights when KOA was who are not already members of the R. M. ante and condenser Model very strong, there was no trace of LR5 on the tester. Tests new metal S., may secure full information tubas and all others, now 305 same frequency, however, at the times KOA was by writing and later. 5" fan -type, weak, LR5 was heard in the background. The to Philco, Philadelphia, Pa. Ask for the plain-view meter. Screw -base best verified station during the last season is June issue of the Philco Serviceman, which, Neon lamp indicates shorts KFDM in Texas, also not to forget KZRM, and leakages to 500.000 ohms. Philippine Islands." in addition to details regarding the telegraph Complete, ready to operate, Observer Mathie (New Zealand) : "I have service, contains other sales promotional $21.95. Money- saving Kit, been showing RADIO NEWS to several friends data of interest to the serviceman. $17.85. here in New Zealand and their comments are uni- versally favorable. Several are now purchasing Write Dept. RN -9 for Catalog your magazine for the DX notes. RECTIFIER CIRCUITS of Other New Tesf Equipment "The South American stations are coming in exceptionally well and at present (June) can be RADIO CITY PRODUCTS CO. heard from 3 p.m. (N.Z. time) onwards. The 28 -30 W. Broadway, New York best received being: LS2, LR5, LR3, LS9, LR4, LR6 and LR8. All these stations can be heard up to 30 feet away from my receiver. Some of the Mexican stations are also good. XEPN, XENT, XELO, XFB, XEW, XEFO and XEAW wai PLANTS being the best. The best DX, however, is log- Kato Hour ging the VK amateurs, some of whom are al- T A little gas and a Kato AC cleat en- lowed on the broadcast band (between 1114 and L ables you to operate AC radios. amph- 1500 kc. after 1 a.m. N. Z. time). These sta- sona refrigerators and other standard hause- hpid DDÜnnce.. Sizes 300 Watts d u tions have a maximum power of 25 watts. So WITH VIBRATOR descriptive literature n DX'ers can imagine how elusive some of them Writ. t , i modtia. AC are. 1YA, Auckland, is now using 10 kw.; 3YA, 84 KATO ENGINEERING CO. Mankato, Minn.. U. S. A. Christchurch, is to be increased from 2.5 kw. AC Oeneraror, 110.00. Conversers fo, 0perenne AC radios from 0. to 1"0 kw. any time now. Tenders have been let 12. 52 and 110 folta DC 118.00. for a new 10 kw. station for Dunedin, and it is reported that the new station for Wellington (to be built next year) will have a power of 60 kw." FIG.G Observer Lyell (South Africa) : "Although the peak period for reception of U.S.A. stations in this country has come not a single U. S. A. FI LTER station has been heard up to the present -not the lien-Had slightest trace. The weather continues unsettled and stormy here -a most unusual thing for this WITH TUBE RECTIFIER Rcxdio Tubos time of the year. The Argentine stations continue to come through during the early morning T '['HE ICEN -RAD CORP., Inc., Owensboro, Ky. hours, although quite a few of the medium - powered ones have not been heard. Even the

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 1s:>

Super DX -8 (Continued from page 145) BUILD YOUR OWN right, the control knobs serve the following pur- Sensational New poses. First comes the "a.v.c." switch; when turned to the right the sensitivity control is manual, turned to the left it is automatic. Next follows the frequency range switch; in the extreme left position the frequency range is from 18 to 9 megacycles. Turning the knob clockwise, the next band covers from 9.5 to 5.5 mc., the third band covers from 6 to 3 mc. and the fourth GEN -RAL from 3.5 to 1.6 mc. Reg. U. S. Pat. The third knob permits switching from speaker to phone. The fourth knob (in the center), is the sensitivity control. Then follows the beat oscillator switch, which is "on" when turned clockwise. Knob number six is the "on -off" SUPER DX -8 CRYSTAL* switch and volume control combined, while the last is the "stand -by" switch which cuts off the plate supply. From this brief description it will be evident Single Signal Receiver that this new receiver provides an array of valuable features usually found only in the more expensive "communication" type receivers-yet Covering 1700 Kilocycles to 18 Megacycles the cost of complete parts to build the "Super DX-8" puts it within the reach of many amateurs and short -wave experimenters who cannot Remarkable manufactured receivers. afford these Low -Cost Parts List Professional 1-Foundation Kit consisting of: Chassis and Short -Wave Panel. Receiver 1- Gen -Ral Coil Kit No. 34 consisting of: with 1 -multi -wave unit -18 to 1.5 megacycles. 1 -LCX 200D -V -M 507 kc. series wound i.f. unit, input -top grid. Electrical 1- LCX200D -V -M 507 kc. series wound i.f. unit, output- bottom grid. Band -Spread 1- Heterodyne Oscillator -507 kc. 3- Planagraph Prints. Tuning and 1 -Power Transformer. 1-Reliance 140 mmfd. band -spread condenser, 'WERE is a most sensational, modern type 2K140. GEN -RAL superheterodyne, a real professional Super DX -8 short -wave receiver that can be built by 2-4 Prong Tube Sockets, 1 % inch mtg. centers. anyone in a few hours of simple home con- Tube Sockets. 4-6 Prong -Wave struction. The development of the new 2 -5 Prong Tube Sockets. Multi 1 -7 Prong Tube Sockets. GEN -RAL Super DX -8 Multi -Wave Coil Coil Assembly Assembly, coupled with superior electrical C4, C6, C7, C27 -.05 mfd., 200 volt. * With or without crystal filter band spread, and simplicity of chassis lay- CS, C8, C10, C11 -.01 mfd., 200 volt. out and wiring, makes possible a pro- C9-.0001 mfd. mica condensers. for the amateur and short 02, C17 -1. mfd. 400 volt. fessional receiver C13 -5. mfd. 25 volt. wave enthusiast, that is comparable to custom built C14, C16-.01 mfd. 400 volt. receivers selling for four times the actual costs. Ask your C15 -10. mfd. 25 volt. jobber for free instructions, which show how to build this C18, C19, C20 -8 mfd. 450 volt. Screw type mounting. remarkable receiver. 16 pages of technical information, C25 -.1 mfd., 200 volt. schematic diagrams, complete details, etc., will be sent C26- .00025 mfd. mica condenser. FREE! Write Today! C28, C29 -.10 mfd., 400 volt. C30 -.2 mfd. 200 volt. C31 -.001 mfd. mica condensers. Special Features of the Super DX -8 I. Band Spread Tuning. Continuous band coverage from 1.6 R1- 25,000 ohm volume control with taper. meg to 18 meg. R2 -150 ohm 1 watt carbon resistor. 2. No plug -in or separate coils. R3- 40,000 ohm I watt carbon resistor. :1. Coil Assembly wired to switch. R4, R8. R14- 250,000 ohm 1/3 watt carbon re- 1. 140 mmfd. variable condenser used. sistor. 5. Beat Oscillator for C. W. signals. RS- 13,000 ohm 2 watt carbon resistor. 6. Pre -selector or R. F. stage minimizes repeat signals. R6-200 ohm 1/3 watt carbon resistor. 7. Stand -by switch cuts off plate voltage while transmitting. R7- 25,000 ohm 1/3 watt carbon resistor. 1t. Manual or automatic volume control. R9- 1,000,000 ohm 1/3 watt carbon resistor. GEN -RAL Super DX -8 wired Multi -Wave Assembly. 9. High Q. radio frequency coils and I. F. R10- 200,000 ohm 1/3 watt carbon resistor. This unique coil assembly eliminates repeat signals, Transformers (piewound). R11-500,000 ohm pot. type volume control. gives individual band switching, with all necessary 111. Sensitivity and selectivity unsurpassed. R12 -5,000 ohm 1/3 watt carbon resistor. padding and trimming condensers wired throughout. 1 1. Chassis base and panel drilled for mounting R13, R17, R21, R22- 50,000 ohm 1/3 watt car- Two I. F. Transformers high "Q" design, series or all parts. bon resistor. piewound, and the beat oscillator, complete coil 12. Switch on panels changes From speaker to R15, R18- 500,000 ohm 1/3 watt carbon re- setup. phones. sistor. R16 -3,000 ohm 1/3 watt carbon resistor. R19 -500 ohm I watt carbon resistor. R20- 20,000 ohm 1 watt carbon resistor. I RIE AND (PARTS LIST W/tia7cdas 6- Aluminum Tube Shields. ASK FOR PARTS LIST NO. 9 2- Rotary Type Switches s.p.d.t. 2- Rotary Type Switches s.p.s.t. 2- Insulated Binding Posts -"ANT." To Your Regular Jobber or Firms Listed Below 1 -Plain Binding Post- "GND." 1 -Pair Phone Tip Jacks. Allied Radio Corp.. Chicago, Illinois Stuyvesant Electric Co., New York, N. Y. Wiring Harness. Midwest Radio Mart, Chicago, Illinois Aaron Lippman & Co., New York, N. Y. 1- Sears, Roebuck & Co., Chicago, Illinois Gross Radio Co.. New York, N. Y. 1 ft. % inch shielding. Montgomery, Ward Co., Chicago, Illinois Radio Specialties Co., Detroit, Michigan 2 ft. shielded wire. Pioneer Automotive Supply Co. Atlas Radio Corp. Toronto 2, Canada 6 ft. power cord with plug attached. Chicago, Illinois (Canadian Representative) 1-8 -inch dynamic speaker, 2,500 ohm field with Pacific Radio Exchange, Los Angeles. Calif. Lew Bonn Company. St. Paul, Minnesota output transformer for 2A5 tube. Radio Television Supply Co., Los Angeles. Calif. Seattle Radio Supply Co., Seattle, Washington diameter black bakelite knobs. Zack Radio Co., San Francisco, Calif. Burstein -Applebee Co., Kansas City, Mo. 8-34q-inch Wholesale Radio Service, New York, N. Y. Portland Radio Supply, Portland, Ore. 1 rubber grommet. -54 -inch diameter Federated Purchaser, Inc., New York, N. Y. Spokane Radio Supply, Spokane, Washington 3 -g -inch diameter rubber grommet. 5 -2 -lug insulated terminal strips. 2 -1 -lug insulated terminal strips. OR WRITE TO MANUFACTURER 2 -Fibre shoulder washers. 2 -Fibre plain washers. 2 -58 type tubes. GENERAL 11ANUFACTURING Co. 1 -2A7 tube. 1 -2A6 tube. Electrical & Radio Coils Cable address "GEN -RAL" 1 -2A5 tube. 8066 South Chicago Ave. Chicago, Ill., U.S.A. 2-56 tubes. 1 -280 tube.

www.americanradiohistory.com 186- RADIO NEWS FOR SEPTEMBER, 1935.

ments: W1AHI, W1DIO, WIAUC, WICHG, Servicemen's Profits WICAV, W1BBN, W1GBE, W1FZO; W2HQY, W2EUG, W2HFS, W2AIT, W2FLG, W2UEP, W2EEN, W2ICU, W2AN, W2CFU, W2ART, (Continued from page 153) W2MB, W2DVU, W2AAK, W2KIZ, W2CLS, W2FKL, W2KX, W2CQK, W2KR; W3AXT, the mere sum of seventy -five dollars. The result WAIR, W3DHM, W3BSY, W3BLO, W3IX; was simply this: He installed a photo- electric cell W4FQ, W4BLH (portable), W4AAK, and relay near the door in such a way (Figure W4BDD, W4DCK, W4DUX, W4AXO, W4KH, I) that when the truck drivers backed up to the W4ALG; WSZS, W5BDB, W5DND, WSLA, building to unload, the rear end of the truck WSDCP, WSECL, W5AEB, W5LAR, WSBGT, would interrupt a beam of light and ring a "loud" W5CCB, W5AXU, WSDG, W5BIN, W5BGW, bell at a critical distance. The man who made .WSPP, W5ZA, W5UN, W5AHJ; W6BGY, the installation did not buy a ,complete photo- W6AQV, W6ZH, W6LR, W6EBJ, W6IZB; electric unit but rather only the components that W7BCF, W7BCI, W7DNP; W8FSA, W8IGO, he could not himself assemble. The ob (with W8FA, W8AMY, W8KAZ, WBCDW, W8JTW, cell) cost him only $25.00. The light source W8HTV, W8JVR, W8KJE; W9NLP W9BJW, was made from an automobile light reflector, a W9DHF, W9GBG, W9GJY (portable), W9PIY, bell ringing transformer and an auto light: W9CET, W9OJC, W9DEF, W9APP, W9ARK, This is the kind of electronic equipment that W9DTP W9GF, W9TPC, W9BJ, W9FQ, these small manufacturers can buy and the radio W9DHC, W9GXE, W9BFC, W9JEZ, W9BIF, man can sell at a reasonable price with some W9RGF, W9QC, W9LBX, W9JNG, W9WX, margin of profit. And there are plenty of other W9LAI; VE1CR, VE2CA, VE2FG, VE2BD, little jobs. that can be done with such equip- VE2EE VE3LL, VE3IX, VE3DB, VE3DF, ment about small plants. Automatic counters VE3K\ , VE4H , VE4NI, VE4BF, VE4GD, can be placed on punch presses (Figures 2) and VE5HN; TI3AV, TI2RC; COfRY,' CO6OM, conveyor machinery, burglar alarms can be in- CO2HY, CO6WW, CO2LL, CO2RA; HJSABE stalled, elevators can be prevented from starting (must be a harmonic), HCIFG,. HI7G, HP1A, until the gates are closed and many, many other HH5PA, XIG, X1W, X1T, VP3BG, VPSPA, chores that only photo -electric equipment can do, VP5PZ, VP6YB, VP6PS, PY1VB, PY1BB; can be done! But this business is not available LU6AP, VK2EP, VK2YW, ZL2KI, ZE1JO ( ?) to fellows who sit in their places of business and LA1G, ON4AU, ON4AC, OK2AK, K4SA, recall the "good old days" when sets were sold K6BAZ, V011, VO8A, CT1BY, EA4AO. with seventy -dollars margin and tubes brought The total list of 20 -meter amateurs (when their a dollar profit for each sale. Get out and get mileage was figured up from New York) total busy-get that brain working along the lines 262,125 miles. I plotted these distances in pointed out here and you also can cash in! some - spare time from airline maps. The log . on 80 meters and 160 meters gave 72,850 miles for the total distance. The log of c.w. stations both amateur and commercial gave a total of 480,645 miles. During these tests I made a habit of tuning in some local amateur with a !t will not lose its calibration. Its resistors will no. stand -by receiver and then tuning the HRO to change value. Its accuracy far exceeds even the Testing the HRO a distant station he was trying to 'QSO.- In best "ohmmeter." Its price makes this laboratory many cases the HRO brought in the complete instrument practical For service work. Ask your (Continued from page 150) return message without interference while at jobber or write for complete new catalog of Muter the same time the local amateur would report products. crystal filter circuit arranged so that it can be QRM. used in this fashion for c.w. reception or, by a The receiver also proved its worth as a very phasing adjustment, for radio telephone recep- efficient short -wave broadcast receiver and one tion where a somewhat lesser degree of selectivity that I would heartily recommend for any Short can be utilized. The set employs 9 -tubes (with- Wave Listening Post Observer. The log shows The TER) Co. out the power pack) using a 58 or a 6D6 in the reception and identification of over 100 short- H wave DX stations, received first and second pre -selector short -wave stages. from 41 foreign A 57 or 6C6 tube is used for the first detector countries, outside the. United States. The total MAKERS OF CANDOHMS and, coupled electronically to this, the oscillator mileage of these stations from New York was tube is of similar type. A 58 or a 6D6 is used 324,660 miles. The calculation for the total 125'5H S. Michigan Ave., Chicago, III. in each of the two i.f. stages followed by a 2B7 mileage of all short -wave stations logged during or a 6B7 for the second detector, with a 2A5 or the week's period is 1,140,280 miles (if I have a 42 tube used as the output. The c.w. oscil- not made a mistake in addition). I consider this lator tube is a 57 or a 6D6, also coupled to the a very excellent record for any receiver. second detector. The schematic circuit is shown I did not do much on the broadcast band with herewith. this receiver as the static on these bands was THE 100% RADIO CATALOG The rack -and -panel mounted job consists of heavy. However, I did identify a few West Oar this receiver, together with the power supply Coast stations and many at lesser distances (which is the bottom unit) ; and the speaker and throughout the United States. The tone quality coil case units. The unit just above the speaker on, broadcast reception was all that could be is the coil case for the calibrated band -spread, desired. Next month I will point out some of ganged, plug -in coils. the technical features of the receiver. The front of the receiver contains the main tuning dial, center, and at left, the S -meter (for THOUSANDS OF PARTS determining signal strength) underneath which appears its push button and a jack for head- SET -BUILDING KITS phones. Just below this is the audio-frequency TEST INSTRUMENTS volume control. Below this is the snap switch Canadian Television for turning "on -or -off" the a.v.c. and the bottom PUBLIC ADDRESS control knob turns "on" the oscillator and gives SHORT WAVE GEAR a small frequency variation for adjusting beat (Continued from page 143) note. Below the main tuning dial there is the ALL -WAVE AUTO drawer of four tuning circuits for a given fre- programs with your chin resting on the re- BATTERY RADIOS quency band, that can be inserted in a jiffy ceiver," says Mr. Peck. "The average radio merely by pulling out on the two handles. At listener sits from 10 to 15 feet from his set the right, the top control is marked "selectivity" while he receives broadcast programs and it is and below that is the control for "phasing" in unlikely that he will change his habits for tele- ALLIED RADIO CORPORATION the crystal circuit. The snap switch, next be- vision. Both theory and experiment prove that low, cuts the B power "on- and -off" and the bot- a 16 -inch picture scanned by 180 lines contains 833 W. Jackson Blvd.. Chicago. lll., Dept. M tom control of all is the r.f. gain (which we all the detail that it is possible for the human formed a habit of keeping fully on most of the eye to see at a distance of 10 feet or more. In Send me your FREE Spring & Summer Catalog time and controlling volume of reception almost other words, any detail in excess of 180 lines entirely with the audio control). We could go Would be wasted unless the observer wanted to on talking about Phis receiver for many thou- sit almost on top of his receiving set. Home Name sands of words but as space is limited and as movies can offer no more usable detail than can the HRO Instruction Manual goes into this 180 -line television, when viewed under similar Address matter in profuse detail, we will simply state conditions. We have consistently adhered to some of the results we have obtained with the mechanical scanning because of its inherent receiver. We think that for c.w. reception the superiority over other forms. In the first place, THE ROAD TO A crystal circuit really afforded the sharpest and a cathode-ray tube which lasts about 1000 to 2000 most reliable non- interfering reception that we hours before growing dim, costs approximately MORE SUCCESSFUL have so far had the pleasure of experiencing. $75.00 in a size large enough to produce even a Signals from all over the world were tuned in nine -inch picture. Then, too, our system re- SERVICE BUSINESS and. in many cases, when and if interference quires a maximum voltage no greater than that cropped up, an adjustment of the phasing con- used in the power -stage of ordinary receivers. Rush your request for our trol and the oscillator setting, as new FREE BOOKLET for well as the We use 350 volts, as compared to the cathode- selectivity control, cut it out in every case we ray tube's 1000 to 5000 vblts. Our only elements servicemen only. Let it point tried. This was true of both amateur the way to doing all types of c.w. re- which wear out are the light -valve tube and the service work easier and ception from 10 meters all the way up to the light- source bulb, both of which last some 5000 broadcast frequencies. It was really a pleasure hours and have a combined cost well under two quicker -to building YOUR to be able to control the heterodyne frequency dollars. business on a sounder, more without having to change the tuning or putting successful basis. Hundreds of it frequency "We are now completing a new scanning sys- enthusiastic users throughout "off ". tem which is smaller and lighter than any here- 20 -, the world. You can't lose! Let On the 80- and 160 -meter amateur phone tofore constructed. It is driven by a 1 /100 us send the booklet withoüit bands the receiver well demonstrated its excep- horsepower motor-smaller and cheaper to op- delay. F. L. Sprayberry, tional sensitivity and selectivity (especially when erate than many electric fans. And our light - 2548 University Place, N. W., the phasing adjustment of the crystal yas used) valve is operated by only 1/20 watt; it cannot Washington, D. C. and many hundreds of amateur stations were overheat! Add to this the fact that our picture actually logged on my log sheets. To cut a long is in black- and -white, as compared with the SPRAYBERRY'S PRACTICAL matter as short as possible, I am listing some of cathode -ray tube's varying shades- of pea -soup the American and foreign call letters from the green and you have several good reasons why 20 -meter band log. These calls were MECHANICS ¡Zpptp SERVICE written we believe the mechanical scanner, with its low- down, as heard, during the station announce. initial cost and its freedom from trouble, to be

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 187

the only answer to the problems which have pre- ninth district station using only 3 watts viously confronted television." input. The 9, despite the low input, was It has consistently and repeatedly been stated that television is still several years away. Peck, R8 in New York. on other hand, claims he has produced a On the other hand, a number have put system which the press and the public have pro- high power on 10 meters. Several are nounced satisfactory. So Peck readily admits that television has arrived. You can look for using as high as 500 watts, but the average announcements by leading Canadian radio man- is far less. Most of the "boys" on 10 are ufacturers, in the very near future, stating the using less than 100 watts and are doing appearance of Peck receivers on the market - and at a surprisingly low price. The Federal excellent work. Communications Commission in the United The chief obstacle in 10 -meter trans- States has, in all good faith, been guided in mission and reception is the antenna. It some measure by the statements of leading radiomen in making its estimate of the status of tele- requires much experimentation and care in vision, according to general rumors. Conse- its erection. It is desirable to make field - quently, the Commission has made it rather strength measurements and adjustments difficult for the independent television companies to secure broadcasting licenses here. But when until low -angle radiation is obtained. A Mr. Peck went to the Radio Commissioners of vertical antenna, of course, is best. If a Canada, explained his system to them and horizontal antenna must be used, a full - showed them evidences of performance, a Can - adian license was promptly granted, and VE9AK wave Zeppelin gives better radiation char- came into being. acteristics than a half -wave horizontal. w IIYJY6S A diagram of the receiving apparatus which Ten meters is ideal for summer work, in Canada will soon be commercially available due to the complete absence of is shown on these pages, together with a brief almost description. There are, however, two features static. However, if you are unfortunate of the commercial job, full size working models in being located on a much -traveled high- by Peck, which will of which have been produced way, it is not so good. Ignition QRM is be of interest to every radio -minded reader. A good antenna is as necessary to fine re First, the cabinet is entirely different from the chief source of interference -Packards ception of short wave programs as the tubes the earlier odd -appearing television receivers and Fords being the most serious offenders! themselves. If you would like to bring which have been produced in the past. With at without the top closed, it looks like any handsome con- 100 Miles on 5 Meters in foreign stations any time sole radio receiver. But when television images the usual man -made interference, get a is lifted, are being received, the top of the cabinet NEW YORK, N. Y.-About a year ago, view Brownie All-Wave antenna. Your like the lid of a phono -radio combination, and the 14 -inch by 16 -inch ground -glass screen, upon Mr. James Millen (W1HRX) of Malden, Brownie will not only outreach any other which the picture is reproduced, automatically Mass., and the headquarters of the Ameri- antenna, but will add new high fidelity to swings into place. This screen is removable, can Relay League (W1AL) at West Hart- local broadcasts. however, so that a larger picture, up to five feet wide, may be projected onto the wall. ford attempted to form a chain of The Brownie is made by an old established Second, the same cabinet that contains the ultra- short -wave stations which would link maker of electrical products- constructed television receiver equipment also houses an all - Malden, Hartford, New York, Baltimore on the famous Doublet System and wave radio broadcast receiver and high -fidelity loudspeaking system. In this way, the set owner and Washington. Now a report comes from equipped with a super-efficient matching is assured not only of the sight- and -sound pro- amateur station W3AZG at Riverton, N. J. transformer. You won't believe Brownie grams being sent out by the Peck station, but results Fits set (across the river from Philadelphia) that until you try it yourself. any of all the sound broadcasts any other radio set and is easily installed. At your dealer's will receive, as well. a conversation between Station W2DLG, Programs, long a bugaboo of television com- the Hotel New Yorker and station or write direct to: problem to the panies, present no particular W2AMJ in Bergenfield, New Jersey, was PORCELAIN PRODUCTS, Inc., Dept. E, Findlay, Ohio Peck Corporation, which uses films and is now opening negotiations with the 'leading producers picked up at Riverton. This establishes a to make comedies, animated cartoons, features, 100 -mile communication on 5 meters which ALL - W AVE shorts and musicals available on the air. This, is something of a record. The station at it is expected, will give the "looker -in" the BppwNIE ANTENNA greatest stars of the screen as ordinary enter- the Hotel New Yorker, was operated by Mr. Arthur H. Lynch and the station at tainment. t_EA Le AGq/h4.. Besides this, Peck is planning to use his W2AMJ is owned and operated by Mr. direct pick-up for sports, dramatic, educational MQERITE0 and musical broadcasting. He does not worry Frank Lester. This event has given new s about where the talent is coming from, but hope among the amateurs for the possi- points to the precedent of radio, which simply of covering larger distances with Peck organiza- bility went ahead and did the job. The -waves. A new series HIGH IMPEDANCE tion will, until television stations are permitted ultra- short of tests to sell time, defray the costs of talent, being is being organized in order to try to bet- VELOCITY MICROPHONE Peck reimbursed by income from the sale of ter this record. (-Nov," RB-H television receivers by companies licensed to manufacture them. After television stations are 6B5 permitted to sell time, as do broadcasting sta- The New Tube (/1L7a:es WITHOUT PRE-AMP, tions, the talent bill will be defrayed by spon- PROVIDENCE, R. I. Triad Mfg. sors. -The Mr. Peck is also planning to open a station Co. of Pawtucket, R. I., has put on the in the United States some time before the corn- market a new tube designated as 6B5, A HIGH REQUIRES NO IMPEDANCE PRE - AMPLIFIER ing winter. Other than stating that it will be which represents a radical departure in located in the New York area, and will operate V E L O C I T Y WHEN USED WITH with sufficient power to bring his broadcasts to tube construction. The 6B5 is an improve- MICROPHONE R E G U L A R some 10,000,000 people, he refuses to comment ment on the former 2B6, or triple -twin WHICH OPERATES HIGH GAIN until final arrangements have been completed. DIRECTLY INTO AMPLIFIER tube, but the cathode of the input section GRID OF TUBE (100 DB.) is internally connected to the grid of the Ten Meters Active Again output section and not to any prong on the tube base. To all appearances the Several months ago we had a depart- plate circuit of this first plate section is Replaces condenser and crystal microphones-NO ment devoted to activity. It not closed. However, the output section is CHANGES or additions necessary! ELIMINATES plea for has INPUT TRANSFORMER and its losses. . . There- seems as though our activity a tube with a very high amplification fac- fore requires 12 db less over-all amplification... been answered, as during the late spring tor which is so designed that the grid cir- Eliminates inductive hum. No feedback. Life -like, and early summer a number of, new sta- cuit impedance serves as the output im- natural reproduction. Write for Bulletin H. tions appeared on the band, supplement- pedance of the first section. In this way LIST $42.00 with coupling. ing the number of pioneers who have it is possible to eliminate a great number MPERITECorporation s61 BROADWAY NEW YORK stuck by the band during periods of good of parts and accessories which otherwise and bad activity. would have been necessary. For instance, During the last spring the band seemed it is possible to replace a 42 pentode by a to open up for some real DX. Increased 6B5 and have a few parts left over. For activity may be partly responsible for this. such a replacement the bias resistor should A number of stations have put exception- be short -circuited; no other changes are ally fine transmitters on the band, and it is necessary. The 6B5 in such a circuit will not uncommon during favorable conditions deliver approximately 4 watts. to hear out -of- district stations and even It should be understood that the 6B5 some out -of- country signals. tube is not a Class B tube, but it is a tri- One of the most active pioneers on the ode tube designed and employed for Class band is W2TP. 2TP's present layout uses A reproduction. The filament requires a a 203 -A in the final amplifier with about potential of 6.3 volts and a current of .8 200 watts input. He may be heard almost amperes. When used as a single ended every Sunday afternoon working DX with amplifier the ratings are as follows: out- good reliability. W2TP has been on the put plate, 300 volts; input plate, 300 volts; band since 1928 and still sticks by it, al- grid bias, 0 volts; output plate current, ternating his activity with 20 -meter opera- 45 ma.; input plate. current 8 ma.; am- tion. He was heard recently working a plification factor, 58; plate resistance,;

www.americanradiohistory.com 188 RADIO NEWS FOR SEPTEMBER, 1935

24,100 ohms; mutual conductance 24,000 ments of the 85 tube, resistance coupled to the 'volume control in the grid circuit of the load resistance, 7,000 ohms; manual microohms; 76 first audio amplifier. - Coupled to the second Anybody Can Make power output with 5% total harmonic detector in the 76 audio oscillator adjusted for distortion, 4 watts; input volts for rated maximum signal strength and a clean, stable note. power, 15 volts r.m.s The visual tuning meter is a vacuum -tube NOISE The tube can be employed with the voltmeter, and swings on very weak signals. same supply voltages in a push -pull circuit. In conjunction with the sensitivity control, it can be used for signal strength measurement ELIMINATORS In that case, the load resistance from plate from day to day, or as an R-meter. The signal to plate should be 10,000 ohms. The total voltage amplified and rectified by the 6B7 is power output is then 10 watts. Further, further amplified by the triode section of the 85 BUT IT TAKES before it, is applied to the tuning-meter. the tube can be employed in a "high ef- The three -stage audio amplifier starts with the ficiency push -pull" circuit. The character- 76 voltage amplifier which has bass and treble Experience istics for this circuit are: plate supply, 400 compensation (boost) controllable by,:the separate Bass and Treble tone controls. feeds volts; fixed grid bias, minus 13 volts, or, It THEM WORK through a Clough tuned push -pull transformer TO MAKE self bias resistor of 140 ohms shunted by to She pair of push -pull triode connected Class 25 mfd., or, reduction of input plate volt- A 42's in the audio driver stage of the power amplifier. age to 270 volts. Static output plate cur- This push -pull stage feeds the four 42's in rent (per tube) 40 ma.; static input plate the triode connected Class A Prime power out- current (per tube) 6.5 ma.; load resistance put stage. The audio amplifier (including all preceding r.f. and i.f. circuits) can be adjusted (plate to plate) 10,000 ohms; power out- by means of the two tone controls to be flat from put at 5% total harmonic distortion, 20 30 to 9000 cycles, or to be up 8 db. at bass and Filterettes watts. Under these conditions an input treble ends, or to be down 30 db. at bass and treble ends for very weak signal reception in Trade Mark Reg. signal of 60 volts r.m.s. must be applied noisy locations. Undistorted power . output is from grid to grid. -35 -36 watts with 5% total harmonic distortion.. are backed by the practical know! Harmonic distortion is below 1% up to 10 -watts edge of competent interference en output, and below 2% up to 20 -watts output. gineers, experienced in solvin! The power supply uses the 5Z3 rectifiers in every type of noise problem. parallel for ample safety factor to furnish a A 19 Tube Set total of 388 volts at 240 nia. to the tuner and Not boastfully with confidence amplifier. The large flat mounting power trans- -but former has an electrostatic shield for line noise born of many years' successful ehm (Continued from page 146) reduction. It feeds the three section filter ination of every known type o which uses an input choke cushioned on rubber radio noise say "Bring of compensated first audio amplifier to prevent vibration destroying quality in high -we 2 -42's as triode connected Class A audio driver fidelity reproduction, and the two speaker fields. your interference! Be it a tin, stage A total of 46 mfd. of wet electrolytic capacity is appliance or a whole street rail 4-42's as triode connected push -pull parallel, used in the filter, its last two condensers being way system TOBE FILTERETTE! Class A Prime 35 -watt output stage the new self -regulating type which automatically 2 -5Z3's in parallel as rectifiers regulate power supply voltage as tubes warm up. will STOP THE RADIO NOISE!' The output amplifier feeds the speakers, the In terms of sensitivity, no difficulty is had 13 -inch bass speaker covering the tone range of Write today for latest Noise Bulletin in obtaining % to % microvolt absolute on all 30 to .4000 cycles, and the 5% -inch "tweeter" F -635, or send 50 cents for big 76 five bands. Outstanding, however, is the use or high- frequency speaker overlapping at 3000 page noise manual. of two r.f. stages on all tuning bands. The cycles and going on up to 9000 cycles. A voltage amplification of these two stages is 400 simple dividing filter is used to level off the times as against approximately twenty times 3000 -4000 cycle overlap range. TOBE DEUTSCHMANN CORPORATIOI for the conventional single r.f. stage. In actual Such then, is a general description of a flexible Filterette Division practice, the two r.f. stages coupled with i.f. all -wave receiver designed to satisfy every re- gain so low as to introduce no i.f. noise, result quirement that can be set up today real MASSACHUSETTS. in total inherent noise of not over 20 milliwatts, -a CANTON, musical instrument, and for the - broadcast or with a 1.0 microvolt unmodulated carrier ap- short -wave DX- hound, a real distance- getter on plied, which when modulated 30% at 400 cycles all wavelengths. produces a total signal output of 500 milliwatts, thus giving the signal to inherent noise ratio of 25:1 with all receiver controls wide open! To successfully utilize such available sensitivity on weak signals also requires a high order of frequency stability to prevent "drifting ". Navy Searchlight - All r.f. inductances are adjusted for absolute uniformity, and all r.f. oscillator and i.f. cir- ("Continued page 140) cuits are tuned with air condensers which are from impervious to humidity, temperature and vibration. Going even further, inductances, air - able soon for President Roosevelt in addressing trimmer condensers and even tuned circuit wir- huge -crowds on the White House lawn. Lack ing are heat isolated and shielded from tubes of adequate loudspeaker facilities for the Presi- and bleeder resistors. These precautions pro- dent's recent addresses on the lawn are said to of dial calibrations and of have prompted this action. - Into a vide permanence Get Line original sensitivity and selectivity. - It is probable that the new device will soon In Figure 1, the tubes at the immediate left be made available through the regular com- Where There's of the gang condenser shield, rear to front are: mercial channels of the Gray -Bar Company. Analyzer & first r.f. stage, second r.f. stage, first detector, It had been called, during a recent demonstra- Action -Every Day - Resistance and 76 oscillator. A total of four sets of five tion for the sales force of this company, "The r.f. tuning inductances each are located in the Bull Horn ". The suggestion has been made And a Payday Every Tester - eight round copper shields at the right of the that all American vessels be equipped with a Latest chassis. device of this kind for emergency operation Week -You Be the Boss! Design-` Examining the circuit diagram of Figure 3, where spoken directions or commands may,, be the three i.f. tubes are coupled by high Q, "3 heard above the tumult of the wind and wave Right now while hundreds are look- Yours With- section Litz -wound transformers TO, T6, T7 and or the crackle of flames, for rescue purposes. ing for work where there isn't any. out Extra T8. For high fidelity (broad) reception, switch the radio service field can - use trained men. With the proper Cost SW2 cuts out the first two stages. Gain is training and the necessary equip- more than sufficient with the single remaining ment, you can enter this field and make a comfortable liv- i.f. stage for reception of local stations, or sta- ing. We include with our course this modern set ana- tions strong enough to override all local noise lyzer and trouble shooter without any extra charge. This Radio Work Shop piece of equipment has proved to be a valuable help to and interference. our members. After a brief period of training, you can For the 18,000 cycle admittance band needed take ,the set analyzer out on service calls and really com- for full range high -fidelity reproduction, i.f. (Continued from page 183) pete with "old timers." We show you how to wire transformers T7 -T8 are over -coupled, and ad- rooms for radio -install auto sets-build and install short -wave receivers -analyze and repair all types of justed for a band -pass resonance curve having a radio sets -and many other profitable lobs can be yours. substantially flat top and steep sides for elimina- An Improved Microphone Teaching you this interesting work is our business and tion of adjacent channel heterodyne whistles - we have provided ourselves with every facility to help you hence the 9,000 cycles cut -off. Connection learn quickly yet thoroughly. If you possess average in- When the two extra i.f. stages are cut in for telligence and the desire to make real progress on your In the usual method of double- button own merits, you will be interested. selective distant reception, they narrow the admittance band down to about 8 loc., yet without microphone connection, employing a center - serious side -band cutting. The gain contributed tapped coupling transformer, there will be ACT NOW -MAIL COUPON by the first two i.f. stages is only 12. This low Start this very minute! Send for full details of our plan gain is intentionally obtained at quite some more current flowing in one -half of the and free booklet that explains how easily you can now effort in order to keep down inherent circuit transformer than the other unless both cash in on radio quickly. Don't put it off! Write to- Send Now! noise. buttons have exactly the same resistance, day! Following the i.f. amplifier is the amplified control system which not only with resulting partial core saturation. In TRAINING ASSN. of AMERICA automatic volume RADIO order to eliminate this unbalanced current - Dept. RN -59, 4513 Ravenswood Ave., Chicago, II 1, levels off output at maximum undistorted power output on weak signals in order to eliminate through the transformer, the writer devised Gentlemen: Send me details of your Enrollment Pl an but also prevents input r.f. and information on bow to learn to make real mono y fading and blasting, a circuit whereby the microphone trans- in radio quick. amplifier overload on strong local stations. The a.v.e. actuating voltage is taken from the former carries only the modulation current. highest voltage point -the last i.f. plate, further The circuit is shown in Figure 1. Since Name amplified by the pentode section of the 6B7, then rectified by its diodes and applied to the the transformer carries no microphone cur- Address first and second r.f., first detector, and second rent, the center -tap is not needed. A close and third i.f. control grids to automatically regu- study of the circuit reveals that it is merely i late sensitivity and volume. City State of the diode ele- an adaptation of the Wheatstone bridge 1-- ..J The second detector consists

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 189

where the two form two All the cham- buttons arms of The QUICKEST WAY pions use the the bridge and the potentiometer forms Candler Method; to LEARN CODE T. R. McElroy, the other two. official speed 77 Figure 2 shows the circuit in The Famous Candler WPM; Jean Hud- bridge Scientific Method son, 9 year old form. R1 and R2 are the resistances of World's Cham- CANDLER GUARANTEES pion Class "E" the carbon granules, about 100 ohms each. that you can learn to pass the WIBGL, Byrd Ex- When R1 and R4 are equal to R2 and R3, examination - for either your pedition. Amateur or Commercial Li- the bridge is balanced, and no direct cur- cense quickly and easily at HOME. Learn CODE by SOUND just like you read a rent flows through the transformer. How- newspaper by sight. ever, if Rl increases while R2 THOUSANDS of BEST and FASTEST Amateurs and decreases Commercial Operators have been trained by Original CANDLER Sound Method in past 24 years. It MUST ?, BE RIGHT. Ask any Skilled Operator! Ask the oo CHAMPIONS! P FREE -New 1935 BOOK OF FACTS 11 for Amateurs and Com'I Otis., lust off the press. Send for it today. Explains everything. Whether you want to learn CODE or develop Championship Speed, it will be valuable to you. CANDLER SYSTEM CO. Dept. 6 -8 RDS" 6343 S. Kedzie Are. Chicago 1935 Sales 100% over 1934 1934 Sales 85% over 1933 SUPPRESSED 1933 Sales 65% over 1932 KNOWLEDGE OF THE AGES These records prove our claims! Hidden, denied, but not lost, is the miraculous C -D condensers must be superior wisdom of the ancients. Their methods of mental power in achieving SUCCESS and MASTERY IN UPE are to receive such world -wide accep- availoble TO YOU. Write for a FREE copy of the tance. "Wisdom of the Sages" and learn how to receive this rare knowledge. MAKE YOUR UPE ANEW. THAT IS WHY C -D condensers are Scribe: N.Z.J. found moving over ROfICRUCIAN BROTHERHOOD the counters of SAN JOSE CALIFORNIA the country's leading distributors and on the work benches of the nation's successful servicemen. Get the latest information on the exclusive C -D patented electrolytic development, the "hi- formation" manufacturing process, from RAYT1I EON your C -D authorized distributor or write direct for a copy of Catalog 128. 4- PILLAR RADIO TUBES CORNELL- in resistance, from modulation, the bridge DtiBILIER becomes unbalanced and the modulated COR P O R AT I O N current flows through the windings. It is not necessary to measure the micro- 4387 BRONX BOULEVARD phone current through each button indi- NEW YORY., U. S. A. Free! vidually, because when the bridge is balanced the current through each button is 1935 the same. In balancing the bridge, adjust the microphone current to the desired value, then Radio Man's disconnect one end of the battery and move the potentiometer arm back and It forth while rapidly tapping the battery Guide connection on and off until the loud clicks from the loudspeaker disappear. If de- with sired, a milliammeter may be placed in A COMPLETE series with the microphone transformer to NOW- 5 Issues Radio News $1e indicate zero current when the bridge is GROUP HEARING AID at balanced. WITHIN THE REACH OF ALL JESS M. REED, Profit for the serviceman. Manufactured by the world's You'll find the 1935 RADIO MAN'S GUIDE Los foremost producers of group hearing aid equipment. Angeles, Calif. to Dept. R.V9 packed from cover to cover with radio Write valuable in- TRIMM RADIO MFG. CO. formation. Every one of its 64 (7 %" x 11") pages is Bias Adjuster for Battery Sets 1528 Armitage Ave. Chicago, III. crammed with information never before published Many battery receivers, especially those using pentode in book form! It gives constructional details on type tubes in the output stage, have a distorted or thin tone when broadcast, short -wave and all -wave receivers tells how to build your own servicing equipment WE STOCK - A COMPLETE LINE OF features over 10 pages of valuable servicing data NATIONALLY ADVERTISED -and presents short -wave and DX aids. RADIO EQUIPMENT Other sections include: radio amateur abbrevia- FOR tions -hints on R. F. Amplifiers for amateur SERVICEMEN- AMATEURS transmitters -powerful P. A. systems -charts for DEALERS - EXPERIMENTERS experimenters -and lists of U. S. and Foreign Write for Free Catalog Broadcast Stations, Police Radio Stations and Leading Short -Wave Stations. CAPUROPIO 601.3 GRANT ST. w 30 TWELFTH ST. Get your free copy of the 1935 RADIO MAN'S PITTSBURGH, PA. WHEELING, W. VA. GUIDE now by subscribing for 5 issues of RADIO Established 1919 immilm NEWS for only $1. (Canada $1.25-Foreign $1.50). ® the B battery voltage begins to Send your drop. This RADI remittance to is usually due to incorrect C bias for that on ENGINEERING, Radio News particular voltage the plate of the tube. broadcasting, aviation and police radio, servicing, marine The diagram shows a bias adjusting ar- radio telegraphy and telephony, Morse telegraphy and railway accounting taught thoroughly. Engineering Dept. 359, 461 Eighth Ave., New York, N.Y. rangement which will overcome this diffi- course of nine months' duration equivalent to three culty, since it allows the bias to be set years of college radio work. School established 1S74. at All expenses low. Catalog free. the point where best results are obtained. Dodge's Institute, Oak St., Valparaiso, Indiana

www.americanradiohistory.com 190 RADIO NEWS FOR SEPTEMBER, 1935

A 50,000 ohm _ potentiometer can be used. A lower value would result in a wasteful drain of the C battery. THllhíFflßÑI The same idea is applicable to electric THAN YOU HAVE EVER HEARD BEFORE sets and is helpful in preventing harshness, especially in short -wave receivers. H. D. HOOTON, Beech Hill, W. Va. CATALOG ata-hthSCOTT Chock full of BARGAINS in RADIO SETS, Long and }ull unyèflOidetíty Shielding With Tin Cans Short Wave Apparatus, Ser- laceme s -Repair and Re- -AL EWAVE I find that tin coffee cans make excellent placement Parts. .Appliances and hundreds shields both in r. f. and a. f. circuits. of miscellaneous Specials at Again. SCOTT steps out. For the first Obtain a coffee can with the patent lock- TREMENDOUS SAVINGS. time in radio history the startling new Get tide b new Bargain L F. Selectivity- Fidelity Control coming- cover, these have short grooves around Book. It's a solutely FREE bined with Super -Power 50 -watt ampli- the sides that lock with projections on the without obitgaUon -fusi send US your Name and, Address on a post card. fier enables the most exacting listener top of the can edge. A to tune right through his powerful local slight twist and the RADIO CIRCULAR CO., INC.1 stations and bring in with unequalled 225 Varick St., Dept. R. N., New York, N. Y, trueness of tone, countless new foreign stations , - .. stations until now blank- 11 eted from any receiver. . 4 POUND COFFEE Unchallenged Proof II CAN INDEX OF ADVERTISERS LOCKS Of Scott Superiority! IN TO COVER Aerovox Corp. 179 Most receiver manufacturers claiming % Alden Products Co. 190 10 K. C. selectivity are able to separate Allied Radio Corp. 184, 186 stations only when the field strength of ili American Transformer Co. 180 the stations is practically the same. The INSTRU- Amperite Corp. 181, 187 SCOTT is the only AllWave receiver MENT i I' which can separate stations 10 K. C. TO BE II' Ii,r ¡;I Birnbach Radio Co., Inc. 192 Bond Radio 192 apart when the nearby station has a field SHIELDED_ PATENT Co. strength 10,000 times greater than the , i LOCKI NG Cameradio Co. 189 distant station. Thrill to the marvels DX CAN enthusiasts acclaim. Try .the SCOTT Si Candler System Co., The - 189 AllWave on 30 day trial in your home COVER Capitol Radio Engineering Inst. 182 (in the U. S. A. Central Radio Laboratories 183 _ only). Sold di- R_"'allMfaic4111111;741 Classified Advertisements 191 l'' rect from the Continental Carbon, Inc. 192 laboratories. Cornell -Dubilier Corp. 189 BASEBOARD Cornish Wire Co., Inc. 187 /CAN COVER OR PANEL GROUNDED Coyne Electrical School 192 Deutschmann Corp., Tobe 188 Dodge's Institute 189 E. H. Scott Radio Laboratories cover is removed. To use as a radio shield, 4440Ravenswood Ave., fasten the cover to the baseboard or panel Eastern Radio Specialty Co. 183 TODAY send Dept.5P5, Chicago Electrad, Inc. 172 coupon for the . Send full details on New SCOTT with small bolts, which are grounded. The comparative transformer or other radio part is then General Electric Co. Second Cover check list giv- Name mounted inside of the cover. Then the can General Manufacturing Co. 185 ing "94 reasons Street for SCOTT is inverted and twisted into its locked Hammarlund Mfg. Co. 171 Superiority.' City State position. Hygrade- Sylvania Corp, 175 L. B. ROBBINS, Become a Radio Expert Indiana Technical College 171 Harwich, Mass. Instructograph Co. 183

Engraving Kink Kato Engineering Co. - 184 An Kenyon Transformer Co., Inc. - - 176 OIDJOBS After reading the Experimenters' Depart- Ken-Rad Corporation, Inc., The - 184 ment for a great many years I have de- McGraw -Hill Book Co., Inc. 181 send in one of my own experi- learn RADIOTELEVISION cided to Fourth Electricity-Talking Pictures -in Los Angeles ments and hope that others may benefit Midwest Radio Corp. Cover Learn profitable trades by practidal shop methods- Enroll with. Na- Mid -West Radio Mart 184 te 1-oldest, largest trade school M the West. 30.000 graduates. from this suggestion as I have from their Muter Company, The 186 Qualify as a radio pair' man; television pert;'sosound d expert;pert; broad-broad - caster;eater; station technician; n -and -for many 'Earn ideas. board while learning. Biggest opportunity for you. For limi- National Company, Inc. 177 ed time wilt allow ,coach .railroad fare to.Los Angeles. Send, for free Recently I completed the construction of book which gives full detail abent different iobs you can qualify,:foe. National Radio Institute 129 complete course f instruction and photographs of school - operations. a set analyzer and the only remaining job National Schools 190 Sign and mail coupon. was the engraving of the panel. Inquiries National Union Radio Corp. 180 NATIONAL SCHOOLS, New York YMCA Schools 191 Dept. 9.RN, 4000 5o. Figueroa St., Los AngelesAngeles, Calif. companies Please send me your Big Free Book on Television; Talking among the commercial engraving I Radio and Electricity. Also details of A R. fare offer. ' showed me that the cost was too high for Porcelain Products, Inc. 187 I Name my pocketbook and I decided to try my RCA Institutes, Inc. 174 Address I own hand, inscribing the panel. - 172 `city State RCA Manufacturing Co. I took a small three- cornered file and Radio Circular Co., Inc. 190 ground the end to a sharp point and then Radio City Products Co. 184 LEARN about TYMIT practised lettering and numbering, on an Radio Products Co. 181 Radio & Technical Publishing Co. 192 ENJOY YOUR RADIO. old piece of bakelite. When I thought my Radio Training Association of America 188 Let it sing you to sleep. efforts were in keeping with a workman- Radolek Co., The 191 TYMIT will turn: it off. Raytheon Production Corp. 189 Let music waken you hap- like engraving job I went to work on the Readrite Meter Works 191 pily. TYMIT will turn it analyzer panel and I turned out a first Rider, John F. 179 on at the right time. Don't class job. Rim Radio Mfg. Co. 171 miss an important broad- After inscribing the panel I dipped the Rosicrucian Brotherhood 189 cast. TYMIT is designed solely for your enjoyment end of my finger into a can of white Scott Radio Labs., Inc., E. H. 190 and convenience. Walnut enamel paint and rubbed the paint into Silver, Inc., McMurdo 131 Bakelite and Chrome plate. Solar Mfg. Corp. 181 the grooves of the engravings and with a Sprague Products Co. 176 Size 5"x4"x21/4 ". Weight piece of I wiped excess 24 ounces. A. C. synchron- cloth the paint Sprayberry, F. L. 186 ous movement. Built by from the panel. Three coats did the trick Supreme Instruments Corp. _ 169 the makers of Tork Clocks, America's best known and the job was not hard to look at. for defrosting refrigera- Teleplex Co. 192 time switches. Can be used H. E. GRANCHIE, Toledo Sound Equipment Laboratories 182 . protection, many tors, lighting control for burglar Youngstown, Ohio. Tork Clock Co., Inc., The 190 important household uses. Guaranteed. Price $9.75 Trimm Radio Mfg. Co. 189 postpaid, Catalogue free. Agents wanted. Station Triplett Electrical Instrument Co. 178 Tork Clock Company, Mount Vernon, New York. Foreign Addresses Tri -State College 184 Observer Routzahn (Pennsylvania) suggests Try -Mo Radio Co., Inc. 192 SEND FOR THE LATEST that the DX Corner would serve a useful pur- Tung -Sol Radio Tubes, Inc. 173 and complete authorised information on testing the new Octal pose if it would publish, from time to time, the Metal tubes, the new Octal analyzer plugs with Dual grid cap correct mailing address for some of the foreign United Sound Engineering Co. 174 and 9 wire cable, plug and socket and As a in this he sends Universal Microphone Co., Ltd. 192 associate adapters. the new Octal sockets stations. start direction the new Octal grid clips. etc. in information on a number of stations that he NOW the new "Tuning Fork" clip is available in happened to have on hand at the time. Webster Co., The 171 tyevery type E socket including the new Octal Electrical Instruments Corp. - 1-33 pes. Life tests are now approaching The Editor would be glad to know what other Weston perfect Contacts without failure. readers think of this idea. If you like it, shoot Wholesale Radio Service Co. 178 ALDEN PRODUCTS CO. along such authentic addresses as you have on Wright -DeCoster, Inc. 192 Dept. RN -9 715 Centre St, hand. Those given by Mr. Routzahn are as BROCKTON, MASS. follows: Yaxley Mfg. Co., Inc. Third Cover

www.americanradiohistory.com RADIO NEWS FOR SEPTEMBER, 1935 191

CHCK. Box 821, Charlottetown, P.E.I. HERE IT IS! CJAT. Box 1959, Trail, B. C., Canada. CMCU. San Francisco No. 13, Vibora, Havana, RADIO COURSES Cuba. - CMGF. Gen. Eetancourt 105, Matanzas, Cuba. Radio Amateur Code CMOX. Apartments Hotel; 8 & 19 Sts., Vedae, Havana, Cuba. Radio Electronics CP -4. Cassila Correo, 637 La Paz, Bolivia. All Day I Year Course Cologne, Germany, Reichs- Rundfunf Gef. m.p.h. First Semester Starts Reichsender Koln, Germany. Sept. 23. Mid- Season LR-5. Radio Excelsior, estudios Mainti 462, Semester Starts Jan. Buenos Aires, Arg. 20. Poste Parisien, 4 rue de General -Foy, Paris, France. Radio Operating XEWZ. Avenida Juarez 75, Apartado 291, Mex- Prepare for Govt. ico, D.F. license exam. - YV1RO Apartado 290, Caracas, Venezuela. Resident Courses Radio Servicing SCK. Australian Broadcasting Commission G.P.O. Box 347c, Adelaide, Australia. Write for Booklet Including short wave 4QG. Queensland Division, Aus, Broadcasting New York YMCA Schools Comm., J. W. Robinson, Mgr. T West Ord New York City Street Midwest Tuning Meter Apparently the difficulty which has been encountered by owners of Midwest 1934 Read Classified Advertising - It Pays models 16 -tube receivers has been finally Advertisements in this section twenty overcome. L. G. Chavez, of Los Angeles, cents a word for each insertion. Name and address must be included at the above has been experimenting with this ever since No. 430 Tests Metal Tubes! rate. Cash should accompany all classified the advantages of a tuning meter were advertisements unless placed by an ac- THE Model No. 430 has five sockets that pointed out in this department some are flush with the sloping paneL One socket credited advertising agency. No advertise- months ago. His ments for less than 10 words accepted. conclusion is that the is equipped to test the new 8 -prong metal Objectionable or misleading advertise- only position in which the meter can be ments not accepted. Advertisements for Octal tubes. Another feature of this new used effectively is in the plate circuit of tester is the shadow -type line voltage meter these columns should reach us not later the first i.f. than 3rd of 2nd month preceding issue. tube. The meter he uses is ... located directly above the moving -coil TECK PUBLICATIONS, INC. an 0 -1 milliammeter, shunted by a 200 -ohm type instrument ... which tests Good and 461 Eighth Ave. New York, N. Y. rheostat, and is connected between the plate Bad tube values. Direct reading. Controls filter resistor of this tube and the B -plus are simple and positive in action. This new line. His meter scale is divided into 10 all -type tube tester makes every inter -ele- Agents Wanted divisions which he has numbered in re- ment short and leakage test, in a manner verse. With no signal tuned in, the rheo- AGENTS: Stick -on- Window Sign Letters. 500% instantly convincing to the customer: Re- profit. Write today. Metallic Letter Co., 422 N. stat is adjusted until full -scale deflection movable cover for either portable or counter Clark, Chicago. is obtained (zero on his reverse scale). use. Then any signal tuned At Your Jobber's Correspondence Courses in will cause the needle to move back down the - scale. A . Previous Readrite models can be adapted USED Correspondence Courses and Educational Books high -power local station such as for the new Octal tubes. sold or rented.- Inexpensive. Money -back guarantee. KFI testing ins. (Courses causes the meter to retard the full length Write 0AlabamAlabama. Write today for full information about 'Bought.)ought.) LeeeMMountain, Pisgah, of the scale, distant stations cause less retardation the No. 430 Tester Electrical Supplies and very weak stations cause a barely appreciable movement. Thus he is READRITE METER WORKS INSULATION, wire, varnishes, supplies, etc. Send 3c able to obtain a definite measure of the 171 College Ave., Bluffton, Ohio, U. S. A. stamp for bulletin. Auto Power, 414 -A S. Boyne Ave., Chicago. signal strength of every station tuned in. This information from Mr. - Chavez will Generators-Motors undoubtedly interest a large number of Midwest owners, TWENTY practical and low cost changes converting several of whom have Chevrolet generators into new gener- Ford, Dodge, or or alter- written in asking for specific information ators and motors 100 -500 watt capacity, direct on nating current, with six to 400 volts for radio operation, the proper tuning meter connections light, or welding. Also instructions for rewind- with receiver. power, definitions of electrical terms, etc. this ing armatures; 350 and All in new, revised book with simplified instructions illustrations. Endorsed by thousands -Only $1.00 postpaid. Auto Power, 414 -A S. Boyne Ave., Chicago. - A New Resonator Patent Attorneys THE problem of properly distributing sound in large and booklet free. Highest refer- halls, without echo ef- PATENTS - Advice assured. ences. Best results. Promptness Watson E. fect, is still incompletely understood Coleman, Patent Lawyer, 724 9th Street, Washington, and certainly not yet solved. In one hall D. C. in New York City several large installa- New/ PATENTS. Instn "How to stab Your tions had Rights" and form, "Evidence of Conception"-sent Free! been made by a number of con- Lancaster, Alhvme & Rommel, 414 Bowen Building, cerns, none of them being entirely satis- Washington, Washington, Patents factory. Echo effect would be so bad that RADOLEK. and Inventions no one could understand the speaker. Em- ploying only a single reproducer, AMPLIFIERS and INVENTIONS COMMERCIALIZED. Patented or en- one in- patented. Write Adam Fisher Company, 278 Enright. stallation did get some success but the Missouri. "P.A.SYSTEMS St. Louis, volume of sound was unbearable close to Photo Finishing the reproducer and not enough at other Fifteen powerful, compact, single unit points. amplifiers-at the right price and for TWO PROFESSIONAL double weight enlargements every purpose. From 4 watts to prints, 25c. Mays Photo Shop, The arrangement, pictured above, was 60 and eight watts! Up -to -the- minute. Newest fea- LaCrosse, guaranteed finally found to work well, giving a sur- tures-Tone Controls, Built -in . Mixing EIGHT GUARANTEED prints and two professional prisingly even distribution of sound with double weight enlargements, 25c. Perfect Film Service, but one loudspeaker. Systems, Plug -in input and outputs. LaCrosse, The "Resonator" is an invention of M. A. Volf, of New York, Complete systems for any job. Easy ROLL DEVELOPED, 8 prints, oil painted enlarge- fast installation, you merely plug the also valuable 8x10 painted enlargement coupon, 25c. and is a "different" type of construction. ment, work. Individual units together. Quick service. Guaranteed attention to One dynamic speaker is used in picture. Janesville Film A51, Janesville, Wis. conjunc- each tion with a large number of organ pipes. New 48 page book Radio - These pipes are of different lengths and complete- diameter, each tuned to a different REE ly describ- RADIO ENGINEERING, broadcasting, aviation and pitch. ing the entire line as well as marine and police radio, servicing, Morse telegraphy They are located at various distances from information on Sound Trucks, 'aught thoroughly. All expenses low. Catalog free. the cones, the distance Installations for the Hard of Dodge's Institute, Elm St., Valparaiso, Ind. depending an the Hearing, Call Systems, etc. wavelength of the tone in question. The DX and short wave Fans "Toonrite" Dial brings them theory is that each in. 50c prepaid. 'Toonrite ", Babylon, N. Y. of these pipes trans- mits and reinforces the pitch to which it The RADOLEK Co. Song Poems Wanted resonates and, there being such a large 621 W. Randolph St., Chicago number of pipes, there is SONG POEMS Wanted. Free examination, 50 -50 plan. a pipe for prac- Send me FREE "P.A." Book. Sent Bureau. Salem. Indiana. tically every musical note. The speaker pictured above Wind Driven Lights contains 380 pipes. Smaller Name cabinets have been made for the home, ELECTRIC LIGHTS -WIND DRIVEN -You build having them. Write, Wind Motor, Electric, Ridgway, as little as 65 pipes. Montana Now, however; LAddress we come to the unusual J

www.americanradiohistory.com 192 RADIO NEWS FOR SEPTEMBER, 1935

part, the distribution of the sound. The only way, so the inventor claims, to make qnrt,lAti 1i" " one's self heard all over the hall, is to talk into a shallow tank of water. The speaker, having its pipes vertical, sends the sound J RADIO waves straight downward until they hit the water level. Then the waves are con- IN 12 WEEKS AT COYNE ducted by the water to the edges of the tank. These edges, being at a certain in- The great Coyne shops in Chicago have a world- wide reputation for training ambitious fellows for this big-pay field in only 12 weeks. Then help you by giving you lifetime employment service. By my new plan you can take advantage of their wonderful method of learning -by-doing NOW. SEND TODAY FOR DETAILS OF MY "Pay-Tuition-After- Insulated carbon resistors in all Graduation" Plan standard sizes, 5% or 10% tolerance. Train for Radio in 12 weeks on real Radio, Sound and Television equipment. Send for Bulletins IOI and 102, Free Send the coupon today. If you are short of money I'll send you all details of my JECOINTINEXTIIZ CJIRBONIncl finance plan. If accepted, you won't have to start paying tuition until five months from '13908 Lorain Ave.. Cleveland, Ohio the date you start school, and then you'll havel8 months to complete your payments. Send for Big Free illustrated READ Book telling all. about A ND COYNE and how many earn while learning and training you can get there SE ND CODE without book Ludy or _ /I EwaIYhy^ Learn Easily at Home This Quicker Way uncles. / LLh.. theory. ( No experience needed. Beginners read code quickly, copy accurately. If already an op, speed up your wpm with this amazing improved Master COYNE ELECTRICAL SCHOOL Teleplex. Only instrument ever produced which 500 S. Paulina St., Dept. 65 -3K, Chicago, IN. records your sending in visible dots and dashes on embossed copper tapes -then sends back your own M R. H. C. LEWIS, President key work. Fascinating. fool -proof-gets results be- Paulina St., Dept.65.3K, Chicago, Ill. cause you learn by HEARING as well as seeing. 500 S. Teleplex has taught the code to more students in past few I Send me the BIG FREE Illustrated Book on clination, and the reflecting surfaces above years than all other methods combined. Used by U. S. RADIO with details of your "Pay -Tuition- After- Army and Navy, R. C. A., A. T. & T., and others. We fur- I Graduation Plan. it, distribute the sound in all directions nish Complete Course, With minimum distortion. lend you the New Master NAME Teleplex, and personal Through RADIO NEWS, the inventor instruction with a 1 MONEY -BACK GUAR- ADDRESS offers a complete set of blueprints with all ANTEE. Low cost, easy a job, free, to the Lewis. Write today for ! CITY STATE specifications for such folder R.N. -33, no ob- first 250 readers requesting them. Address ligation. your requests to: Volf Acoustical Labora- TELEPLEX COMPANY WRIGHT- tory, Inc., 48 West 48th Street, New York 76 Cortlandt St. City. New York, N.Y. DECOSTER MASTER TELEPLEX -"The Choice of Those Who Know" Metal Cabinet Speakers Dots and Dashes for the (Continued from page 181) Amateur UNIVERSAL who demands approximately 0 degrees. When the grid 5 -Meter Hand Set of this tube is connected to the controlling A new, 15 ounce, compact hand set- Designed for results 5 -meter transmitters and 5 -meter transceivers voltage of the a.v.c. system, the shaded Highly polished, moulded bakelite units -2000 ohm- angle will become narrower when a sta- ni -polar receiver -High output, single- button Universal microphone of 200 ohms -lift. 4 conductor Model 880 Equipped with a Dynamic in. Exact tuning is indicated $ ß0 tion is tuned cord with color -coded phone tips-List Price,. Speaker with Universal Transformer by the narrowest shaded angle obtainable. Single- Button microphone $6.00. match all output tubes, 2500 ohm UNIVERSAL MICROPHONE CO., Ltd., to 8' 424 Warren Lane, Inglewood, Calif.,. U. S. A. field. List Price Palestine Cabinet finished in black crystalline. Size, Radio in 9" high, 10" wide. TEL -AVIV, PALESTINE -Mr. S. Lubin, "SCOUT" ONE TUBE Model 470 A.C. Field Supply the Managing Director of the Interna- Shortwave Kit and Music Stores of this city Can be assembled by anyone. Corns necessary field excitation for A.C. tional Radio with, blueprints. Uses one 230 Furnishes in the June issue ilo operation of the above model. So $ A .70 corrects the figures given Complete Hit withfone sta- R.C.A. Licensed 30 Tube...... 40 designed as to fit into the housing } regarding the number of broadcasting Set of three extra coils 50 Price. sets in various coun- Wired. extra 50 perfectly. List tions and receiving TRY -MO RADIO CO. INC catalog and name has at present approxi- 85 Cortlandt St. 179 Greenwich St. Write for dealer's discount, tries. Palestine N.Y.C. of nearest Wright -De Coster distributor. mately 12,000 receiving sets of which prob- WRITE IN FOR DETAILS OF SPECIAL 22 RADIO REFERENCE SERVICE WRIGHT -DECOSTER, Inc. St IIlaul`hÌ ónve. ably 70 percent are of American manu facture, says Mr. Lubin. There is a small broadcasting station operating at Tel -Aviv New BIRNBACH which sends out programs on an irregular Five -Meter schedule. A new 20- kilowatt station, to Ghirardi's operated by the Government of Pales- MODERN RADIO SERVICING ANTENNAS be Ghirardi and Freed's tine, is now being built. RADIO FIELD SERVICE DATA $1.00 to $5.25 Power Send for FREE CIRCULAR today! TEN new types of quarter Radio -LL Increases RADIO & TECHNICAL PUBL. CO. and half -wave antennas for 45 Astor Place, Dept. RN -9, New York City portable transceivers, beam PARIS, FRANCE -Since the prohibition arrays and permanent use. 2 of advertising matter on the French Gov- or 3 extensible sections with JOBBERS * SERVICEMEN di- radio stations, the small French threaded end, or fiat end for ernment IWrite for our latest Catalog, covering Re- rect front -panel mounting, or private station Radio -LL has been doing placement and Ham Parts, Amplifiers, P. A. including ceramic stand -off insu - business that the Compagnie Equipment, Radio Receivers, Test Equipment, lator- $1.00 to $5.25 list. In- such booming Accessories, etc. Get your name on our mailing quiries invited on special anten- Nationale de Radiodiffusion, the owner of list for the latest, most reliable, complete and nas for all ultra high -frequency station, could increase its capital con- up -to -date Volume Control and Transformer transmission and reception. the Replacement Manual ever published. is now proposed to increase Write Dept. RN -9 for Data. siderably. It the of the station which is only RADIO CO. RADIO CO., Inc. power BOND BIRNBACH .8 11702 Livernois Ave., Dept. 21H, Detroit, Mich. 145 Hudson Street, New York City kw.

www.americanradiohistory.com The AC 1936 Replacement Volume Control Manual ^ g

Yaxley doesn't believe in resting on its gwows laurels. Its constant ad- THE vances in volume con- FIRST trol development prove EDITION .. that! The latest and greatest edition of the Yaxley Replace- and that was heralded as the ment Volume Control Manual proves it, too ! greatest manual ever published Twenty - four months were devoted to the production of this invaluable book. Five radio service engineers - specially trained for the task - compiled, checked and re- checked the data that makes it the most complete and comprehen- USE THE sive manual of its kind ever offered to you by anyone. Its preparation took plenty of time and plenty of work. And it will Y save you plenty of time, plenty of money, A and plenty of grief. -Y MANUAL The 1936 Yaxley Replacement Volume Control Manual lists more set models than any other. It provides more factual data. It contains a complete and save yourself time catalog of Yaxley approved radio products. No service man can well afford to do without it. It's ...trouble and money complete - authoritative- up- to-date! And it's free. Nir Yaxley Manufacturing Division of P. R. Mallory & Co., Inc. the Indianapolis, Indiana Mail Coupon Now Gentlemen : Please send me- absolutely free -a copy of the for your FREE copy 1936 Yaxley Replacement Volume Control Manual.

Name YAXLEY MANUFACTURING DIVISION Address of P. R. Mallory & Co., Inc. My Jobber's Name is INDIANAPOLIS, INDIANA Cable Address: PELMALLO L

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WORLD'S °NING GREATEST RADIO VALUE z U 0 MCrf ; .,o with New EVERYWHERE, NT are saying: t radio enthusiasts ATRfIC Have you seen the new 18 -tube, 6 -band, TiiI by over Midwest?" It's an performs $250 sets. Approved Acousti -Tone V- Spread LESS TUBES'> improvement over Midwest's 16 -tube set, 120,000 customers. Before you buy any SPIE- Ah.ER so popular last season.. This amazingly radio write for FREE 40 -page catalog. beautiful, bigger, better, more powerful, Never before so much radio for so little is not money. Why pay more? You're triply super selective, 18-tube radio ;TERMS AS LOW AS DOWN obtainable in retail stores . . . but is sold protected with: One -Year Guarantee, direct to you from Midwest Laboratories at Foreign Reception Guarantee and a positive saving of 30% to 50 %. Out, Money -Back Guarantee, FULL-SCOPE HIGH FIDELITY . . . 1936 FEATURES SPLIT -HAIR SELECTIVITY PUSH -BUTTON TUNING SO ADVANCED Now, get complete range of audible fre. made by Now, offered for first time! Simply Midwest's brilliant performance possitle quencies from 30 to 16,000 cycles as being pushing Silencer Button hushes set scores of advanced features, many of them exclu- transmitted by four new High Fidelity Broad- between stations ... while pressing sive. Only Midwest tunes as low as 41/2 meters casting stations- W1XBS- W9XBY -W2XR: Station Finder Button automatically and as high as 2400 meters...6 bands...18 tubes... -and W6XAL. Bring in distant, weak for indicates proper dial position for push button tuning...acousti-tone V- spread design eign stations, with full loud speaker volume bringing in extremely weak stations. ...pre -aged adjustments ...Fidel- AStat...Triple Cali - on channels adjacent to powerful. locals. bration...etc. See pages 12 to 20 in FREE catalog. With first time! E, L, M, Delighted METAL TUBES Six -bands ... offered for A, Super Performance Midwest is furnished with the H and U . make this super deluxe 18 -tube set This wave Davison, Mich. A radio engineer con- the equivalent of six different radios . . . offer bands firmed my opinion that no other new glass -metal counterpart tubes. not obtainable in other radios at any price! Now, thrill - are designed to accept make of radio will compare with my Set sockets to new explorations in sections of radio spectrum that Midwest for tone, selectivity, volume, glass -metal or METAL tubes, with- are strangers to you. Every type of broadcast from North ease of tuning and wider range. It is for FREE facts. and South America, Europe, Asia, Africa and Australia great entertainment. R. F. Collier. out change. Write is now yours. Send today for money -saving facts! Acousti -Tone Praises World -Wide Reception Y- Spread Design DEM DIRECT WITH Maysville, Ky. My friends envy my Midwest and say it beats theirs in price (Pat. Pending) LABORATORIES and performance. It is amazingly sen- Send for FREE No pay prof sitive and brings in Holland, Spain, its to[e pay you bud etc. Its full, rich, non fading tone 40 -page catalog -- advanced illustrating new at wholesale price di, denotes super quality and rect from laboratories SAVE workmanship. W. E. Purdon, 1936 Midwest saving 30% to Rural Route No. 1. models and 50%. Increasing. costs chassis in four are sure to result in MAIL CO.UPON TODAY' higher radio prices o FOR colors. Full soon. Buy before the big advance . NOW FREE 30 -DAY TRIAL OFFER and 40- Scope High Fi- while you can take advantage of Midwest's sensational PAGE FOUR -COLOR FREE CATALOG delity Console, values. You can order your 1936 Full Scope High Fidelity Acousti-Tone radio from the 40-page catalog MIDWEST RADIO CORP., User -Agents at left, shows with as much certainty of satisfaction as if you were Dept. 11C, Cincinnati, Ohio. Make Easy. dispersing vanes and to come yourself to our great radio laboratories. You Without obligation on my part. send me Extra Money exclusive V front save 30% to 50% . you get 30 days FREE trial your new FREE catalog and complete de- Check Here that propel High as little as $5.00 puts a Midwest radio in your tails of your liberal 30-day FREE trial for - Details CI Fidelity waves uni- home. Satisfaction guaranteed or money back. Weite, offer. This is NOT an order. formly to the ear. today, for FREE catalog. Name

MIDWEST RADIO CORP Address DEPT. 11C, CINCINNATI OHIO U.S.A. Town State Established 1920 Cable Address MIRACO All Codes Check here. ìt interested in a Midwest Auto Radio.