OVER 175 ILLUSTRATIONS Radio Create - " Fashion Patterns! - NEW! . An Acoustic "Magnifier" Europe's Ras.,; Was - Making a Hi - Fi Tuner :vicing A. C. - D. C. Sets www.americanradiohistory.com The Best Known Name and the Oldest Trademark in the Business CAPITALIZE on the definite sales advantages of the RCA Victor name and famous trademark. Authorized RCA Victor Radio Tube franchises are available only through RCA Victor Instrument Distributors. RCA presents the "!Magic hey" every Sunday, 2 to 3 P. M., E. D. LT., on the NBC Blue Network. VieZt RADIO TUBES RCA MANUFACTURING CO., INC., CAMDEN, N. J. A Service of the Radio Corporation of America www.americanradiohistory.com RADIO -CRAFT for JULY, 1938 1)/nip/from %8a weehr f o .S0 -- a free Book storied me ínyord this GOOD MY/N RADIO 01,PLOYES HERE'S ONLY factory. Pd 6y S.J.E. "I had an $18 a week job In a shoe "The training National limbo lust itute gave nie hadn't read about the (NAME AND ADDRESS probably be st it today If I was so practical I was sooft ready to make $.;. $10. opportunities in Radio and started training at home icing Radio seta." UPON REQUEST) sly u week in spare time sen SENT for them." months later N. R. I. },btpia)meut De "N. R. I. Training look me out of a low -pay shoo ''When I finished training 1 accepted a jub as "Eight pertinent sent me to Station K VCR as Radio factory job and me Into Radio at good pa. a Radio store. In three weeks put serviceman with L am Radio Engineer at Station operator. Now Radio is growing fast. The field is wide open I I was made service manager at more than twice WSUL am siso connected with Telodsion Sta- I properly trained men." what I earned in the shoe factory." tion N9 %K.,, how I TrainYou at Home to BE A RADIO EXPERT Find Out What Radio and Television Offer Make S30, $50, Mail lile r .pun nu for my Book. "Rich Rewards in Many They're free to any fellow a Week I Also Give You Radio" and siunple lesson. S75 mer IS years old. My book points out Radio's spare Do you too want a better time and full time opportunities, also those coming in This Professional tells about Raio an ;Eansl RH Presidintla job? Do you too want to men trained.) shows t 1s11on ;i shows youa 131 from "si4. more money? Ra- are doing, earning; shows my Money Back "OVA=hli.hCd make Servicing Instrument what they or and full time op- Agreement. MAIL. COUPON in an envelope. pasta dio offers many spare time card- NIli\". portunities for good pay and more oppor- as partof MyTralning on penny post tunities will come with Television. J. E. SMITH, Get Ready Now For Jobs Like Those Here Is the Instrument every Radio expert needs and Pr.aldent, employ engineers, opera- wants -an All -Ware, All-Purpose. Set Senlring In- National Radio Institute. Broadcasting stations A.C. tors, station managers and pay up to $5.000 a strument. It contains everything necessary to measure Dept. CCX many and D.C. voltages and current: to test tubes. resistance: year. Spare time Radio set servicing pays adjust nd align may set. old or new. It satisfies your Washington. D. C. pay $200 to $500 a year -full time servicing jobs ,I. for riving yner . graduate f many $30, $50, $75 a week. Many Radio Experts I era Icing set. .11i 11. Ir.Irrli'r are operating full or part time Radio businesses. Radio manufacturers and jobbers employ testers. I. s inspectors, foremen. engineers, servicemen, pay- J. E- President, Radio Institute, ing up to $6,000 a year. Radio operators on ships SMITH, National get good pay, see the world. Automobile, police, Dept. SGX, Washington, D. C. commercial Radio. loud speaker systems. aviation, obligation. send me free a Sample offer good opportunities now and for the future. Dear Mr. Smith: Without soon. Men I trained u Lesson and your 64 -page Book, "Rich Rewards in Radio." telling Television promises good jobs Radio opportunities. and how I good in these branches of Radio. u about spare time and full time have jobs ran train for them at home in spare time. (Please write plainly.) Many Make SS, $10. $15 a Week Extra u In Spare Time While Learning Age The day you enroll I start sending you Extra N Name Money Job Sheets. They show you how to do Ra- I dio repair jobs; how to cash in quickly. Through- out your training I send plans and ideas that Address ' made good spare time money -from $200 to $500 hundreds of fellows. I send special a year-for City Strate .... .. ..........11x1 Radio equipment, give you practical Radio expe- rience --show how to conduct experiments. build mmmmmmmmmmmm circuits illustrating important Radio I.rtnciples. &m emu samm sae meems......... Please Say That You Sato It u'x RADIO -CRAFT www.americanradiohistory.com IMF adio- raft Foe T SERVICE MAN- DEALER - RADIOTRICIAN 111111111 R 11111111111111111 I I I I I I 11111111 I 11111111111111111 I I I I I I I II I I I I I I I I I I I I I I I I 1111111111111111111111111111111111111 I I I I I I I I I I 1111111111111111111 11111111111111111111I11 m 111111I11111111111111I I I I I111111111111111111111111 m 1111111111111111111111111111111 I I I I I I I I I 111111111111111111111111111111111 HUGO GERNSBACK, Editor -in -Chief Unified P.A. Equipment Harry Paro 28 N. H. LESSEM ROBERT EICHBERG Wax & Oil Condensers in Radio Service Work Associate Editor Associate Editor William Bailey 28 R. D. WASHBURNE, Managing Editor Operating Notes Y9 Useful Circuit Ideas 30 A Wired -Radio "Nursemaid" 31 CONTENTS JULY ISSUE - 1938, Introducing--A 5 -Meter Converter 31 Volume X Number I The Latest Radio Equipment 32 RADIO SERVICE DATA SHEETS: Editorial: Service in Radio Servicing..Hugo Gernsback 5 No. 229 - Motorola Model 8-80 (Golden Voice) The Radio Month in Review 6 Car-Radio 36 Radio in Pictures 8 No. 230-Ditto (continued) 37 Europe's Undeclared Radio War Michael Norton 9 Servicing Questions & Answers 35 Radio Creates Amazing Fashion Patterns Radio Wittiquiz 35 Andrew Halbran and Robert Eichberg IO The First IO Steps in Radio Servicing 49 Television Without Scanning? U. A. Sanabria 12 Hum in Public Address Installations 53 New Radio Service "Car" G. E. DeNike 13 Man Still Champion of the Air Dr. Irving Langmuir 60 America's Radio Colossus 13 Looking Ahead to Television Occupations Servicing Universal A.C. -D.C. Receivers Dr. Alfred N. Goldsmith 61 J. B. Straughn 14 Book Reviews 63 Service Men!- Repair Your Customers' Sets "Better Than New "! George W. Haider 16 Servicing Pushbutton Tuning Systems -Part II NEXT MONTH Charles Sicuranza 18 - New Circuits in Modern Radio Receivers-No. IO TELEVISION NUMBER F. L. Sprayberry 20 Television is now undergoing its final polishing stage Modifying a Older Sets to Receive the 4 High -Fidelity prior to its presentation to the public in workable form. Stations Robert Cobaugh 21 Regular transmission schedules have just been announced How to Make a High -Fidelity Tuner C. W. Palmer 22 by NBC; August Radio -Craft will help you keep abreast of these new and important developments. "Bi- Fonic" Sound Magnifier Robert Livingood 24 Service Men, public- address specialists, radio set build- Matching Loudspeakers to Tapped Transformers ers and beginners also will find in August Radio -Craft A. Coblenz 26 many valuable articles to their individual liking. 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 Published by Radcraft Publications, Inc. Publication office: 29 RADIO -CRAFT is published monthly, on the first of the month preced- Worthington Street, Springfield, Mess. Editorial and Advertising ing that of date; subscription price is $2.50 per year in U. S. and Can- ada. (In foreign countries, $3.00 a year to cover Offices: 99 Hudson Street, New York City. Chicago Advertising additional postage.) Entered at the post office at Springfield as second -class matter Office: RADIO -CRAFT, 520 North Michigan Avenue, Chicago, Ill. under the act of March 3, 1879. Foreign Agents: Text and illustrations this magazine London- Gorringi s American News Agency, 9A Green St., Leicester of are copyright and must not be Square, W. C. 2, England. reproduced without permission of the copyright owners. Puis -Messageries Davison, 4 Rue Faubourg, Poissonniers, France. Melbourne -McGill's Agency, 179 Elizabeth St., Australia. Dunedin -James Johnston, Ltd., New Zealand. Copyright 1938 Radcraft Publications. Inc. 2 www.americanradiohistory.com RADIO -CRAFT for JULY, 1938 TRAIN FOR RADIO IN 12 WEEKS BYMYQUICK, EASY "LEARN BY DOING" METHOD Prepare today to enter a real money -making field . a : _ ,: u le-:=116-- by my quick, easy way to learn Radio. Here in my school you are trained in 12 weeks for your start for a better job and a real future. You do actual work on a great outlay of Radio equipment. The remarkable "Learn-By- Doing" methods used in the great Coyne Shops train you in Radio, Television and sound equipment servicing. Not by books . Not by Correspondence ... But all under the individual guidance of skilled instruc- tors, and only on similar kind of work you will meet out on a real job. My methods make it easy to learn-First you are told how to do a thing - then you are shown how to do it -then you do the work yourself. WHERE ELSE CAN YOU FIND SO QUICK AND EASY A WAY TO GET PRACTICAL TRAINING IN THIS GIANT INDUSTRY? ILL FINANCE YOUR TRAINING in the Coupon TODAY. LET LACK OF MONEY keep you from sending DON'T first and take more than a year to pay for it Learn how you can get training after your regular 12 weeks' after graduation.