IUD 10 Installiti_ Issue kidio r "cab I II Ci hoi Ks HUGO GERNSBACK, Editor ' RADIO CRAFT DEC 1 9 4 8 3o u. s. and ELECTRONICS TELEVJ I CANADA CATALOG OF NEW II I' LCETI ' asf %ume /!fs ElecfranicTest `n6oratary ;a/íóer ., ' sNE(TiP , _ HARTEORO ?1ZCN'^STREET SiEERAOIO. U.S.A, MA1N ADDRESS. VOMAX ", new CARLE New tracer "SPARX "" signal test speaker, u niversal TV sweep AM, FM and generators, and signal bridge, C R laboratory stan- -frequency 3 years and continue its growth. multi N OUR NEW CATALOG you will find com- 500q in dard, waVemete pletely described ten instruments, each We are proud that our efforts to bring test speaker, universal of which is in a special class ... Labora- instruments to the service professional wove fine square tory Caliber Electronic Test Instruments at the research engineer have earned such sine Buy and audio oscillator. prices every technician can afford. Each is overwhelming acceptance. Without our tens your the exclusive McMurdo we could never them from the product of of thousands of customers LCETI plan . the modern plan down while continuously in- favorite ¡obber. Silver .. keep prices which makes available to every service creasing quality, accuracy and all- around technician the same instruments used by "usability ". who design and test the big manufacturers We are ever ready to help you turn your very radios you must service. the shop into a modern, efficiently- equipped Instruments of advanced design . service laboratory with Laboratory Caliber practical application "know -how" translated Electronic Test Instruments. Our new cata- into simple pictorial instruction manuals log will show you how easy this is ... how can amaz- . backed by over 37 years of world - each of these new instruments and famous radio engineering leadership . ingly increase your earning -power have increased LCETI production over efficiency. Send for 1948 -49 LCETI catalog. 1 LABORATORY OVER 37 YEARS OF RADIO ENGINEERING ACHIEVEMENT CALIBER ELECTRONIC 711° sXe.k. w-e TEST EXECUTIVE OFFICES. 1240 MAIN ST., HARTFORD 3, CONN. , I 1 9 A I N H A R T F O R D 3 C O N N INSTRUMENTS F A C T O R Y O F F C E 2 4 M ST., 3 YOU PRACTICE Radio Solder - YOU BUILD this Tester with YOU TEST Radio Circuits like YOU BUILD Vacuum Tube ,ng > "Ideri ng Equipment parts N. R. 1. sends early in this built with parts I send. Power Pack; make changes ,mil Itadi, l'arts I send you. Get course. Soon helps you fix neigh- Build special circuits; learn ho., which give you experience with , ractical experience mounting bors' Radios and EARN EXTRA to locate and repair circuit packs of many kinds. Learn how and connecting parts. MONEY in spare time. defects. to correct Power Pack troubles. YOU BUILD ;Li. ... M o YOU PRACTICE FM (Fre- iienerator for more valualI. ex- quency Modulation) experiments. You Get PRACTICAL EXPERIENCE perience. It ampli - get more experience provides with this u,demodulated signals for many Superheterodyne Receiver Cir- With This Superheterodyne Receiver rests and experiments. uit you build with parts I send. YOU BUILD THIS complete, powerful Radio Receiver that brings in local and dis- tant stations. N. R. I. gives you ALL the Radio parts , . , speaker, tubes, chassis, transformer, sockets, loop'antenna, etc. LEA i ;ADIO BY PRACT/C /NG IN SPARE TIME JP--- WITH BIG KITS OF PARTS I SEND YOU I WILL O. you want a good -pay Job In the fast - Business is booming. Trained Radio Tech- growing Radio Industry -or your own Ra- nicians also find profitable opportunities TRAIN YOU dio Shop? Mail the Coupon for a Sample in Police, Aviation, Marine Radio, Broad. Lesson and my 64 -page book, "How to Be casting, Radio Manufacturing, Public Ad- a Success in Radio-Televisiun- Electronics," dress work. Think of even greater oppor- both FREE. See bow I will train you at tunities as public demand for Television. AT NOME home -how you get practical Radio expe. FM and Electronic devices continues to rience building, testing Radio circuits with grow ! Send for FREE books now! MY COURSE BIG KITS OF ['ARTS I send! Find Out What NRI Can Do For You Many Beginners Soon Make EXTRA Mail Coupon for Sample Lesson and my /NCLUDES Money in Spare FREE 64 -page book. Read the details Time White Learning about my Course, letters from men I The day you enroll I star, sending trained; see how quickly, easily you can EX'T'RA TELEVISION MONEY manuals that show how get started. No obligation ! Just MAIL to crake EXTRA money fixing neighbors' COUPON NOW in envelope or paste on a Radios in spare time while still learning! penny postal. J. E. SMITH, President, Dept. 8NX, Its probably easier to get started now National Radio Institute. Pioneer Home Study flEC7RON/CS than ever before because the Radio. Repair Radio School, Washington 9, D. C. I TRAINED THESE MEN Has Own Radio Service SW Spare Ti.. Winos "I have my own Radio and "1 have been getting receivers Television sales and servicing to repair right along, and with MR. J. E. SMITH, Pres., Dept. SNX business. I get enough repair N. R. I. methods I don't have 1 jobs to keep me going right to spend much time on them." National Radio Institute, Washington 9, D. C. along. " -ALEXANDER KISH. -S. N. STRICKLAND, Mail me FREE Sample Lesson and 64 -page book about 34 Pershing Avenue, Carteret. 191 Dale Homes, Portsmouth, how to win success in Radio and Television -Electronics. New Jersey. Virginia. (No salesman will call. Please write plainly.) Age - -. -. Name Address VETERANS City Zone Stete You get this training in your own home E Cheek if Vet under G. I. Bill. Mail Coupon. i APPROVED FOR. TRAINING UNDER GI BI LL 4 Hugo Gernsback, Editor-in -Chief ItA111/1 Fred Shunaman, Managing Editor - Consulting Editor M. Harvey Gernsback, ELECTRON KS Robert F. Scott, W2PWG, Technical Editor R. H. Dorf, W2QMI, Associate Editor formerly RADIO -CRAFT I. Queen, W2OUX, Editorial Associate Incorporator, Angie Pascale, Production Manager TELEVISION NEWS SNORT WAVE CRAFT Elmer Fuller, Shortwave Editor RADIO L TELEVISION Wm. Lyon McLaughlin, Trademark rag,.,Iered U. S. Palest Office Tech. Illustration Director G. Aliquo, Circulation Manager John J. Lamson, Advertising Director Alfred Stern, Promotion Manager Contents December, 1948 Editorial (Page 21) Multiperception by Hugo Gernsback 21 Electronics (Pages 22 -29) Radar Eyes Bring Safety to Fog -Bound Liverpool by Major Ralph W. Hallows 22 Micro -Waveguides by Virginia Walters 24 New A.F. Power Supply by S. R. Winters 27 Electronics in Medicine, Part IV by Eugene Thompson 28 FM (Pages 30 -32, 84 -89) FM Telemetering Transmitters by Leon Hillman 30 FM Station List 84 Television (Page 33 -34) Gas -Tube Oscillators by Allan Lytel 33 Servicing (Pages 35-43) Radio Set and Service Review (Pilot "Candid TV" Model TV 37) 35 Rolling Our Own Output Transformer by J. R. Langham 38 Columbus Set for Video by David Gnessin 41 Coin Radios -A Good Business by James McDaniel 42 Screwdriver, Voltohmmeter and Brains by H. A. Nickerson 43 Broadcasting and Communications (Pages 44 -46) Installing Two -Way Radio in Taxicabs by Samuel Freedman 44 Audio (Pages 47-48) Home -Built Phono Uses Two Pickups by Harold J. Gould 47 Test Instruments (Pages 50 -53) Push -Button Generator by Robert E. Altomare 50 Substitution Unit -Plus by G. N. Carter 52 Foreign News (Pages 54 -56) European Report by Major Ralph W. Hallows 54 New Telephone Recorder 56 Amateur (Pages 58 -62) More Selectivity for the BC -455 -B by E. W. Williamson 58 Phase -Modulated Exciter by Rufus P. Turner 60 Construction (Page 64) Again this year, radio service men are Regulated Power Pack Has Variable Voltage by W. D. Hayes 64 showing an overwhelming preference for Solar capacitor analyzers-specific- Radio Science (Pages 72 -74) ally for Model CBC, worthy successor Transmission Lines by Robert C. Paine 72 to Solar's famous Model CB, which out- capacitor analyzers com- Departments sold all other bined. The Radio Month 10 Miscellany 77 Radio Business 14 Radio -Electronic Circuits 80 Model CBC is small in size, light in Technotes 66 New Patents 82 weight, big in performance and de- New Devices 68 Try This One 90 pendability ... the ideal low -cost in- Question Box 70 Communications 92 strument for the service industry: People 76 Book Reviews 97 Capacitance range ... 10 mmf to 800 mf Power factor range ... 0 to 50 per cent Resistance range...100 to 7,000,000 ohms "Quick as a wink" Magic Eye Wien RADIO- ELECTRONICS. December, 1948. Volume XX, No. 3. Published monthly. Publication (Mire: Erle Ave.. F to G Strnt, Phil Ölrlphia 32. l'a. Ent reed as seism,' lass r err September 27. 1945. a t the (lost office at bridge balancing 1879. canada. In V. S. supply Indladelphla. l'a.. I the Art of ,Iaveh 3. SUBSCRIPTION RATES: In U. S. and Built -in adjustable voltage power puss.SN han. MON i, 0, $00111 MAI Central American countries. $3.50: $6.000 for two years: $4 IIO ror t lire.. sears. Simplified leakage and Insulation Resist- countries a sear, x5.06 for two years. SI I.00 for three years. .UI ncr a one single copies 'oc. All other $4.50 ance tests month for change of address. When ordering u change please famish an adress stencil impression from a recent to read clear scales h pprr. Easy See'y. tRAOCRAFT PUBLICATIONS, INC. Ilugo Gernsback. lies.: M. Harvey Gentshark V1cePres.: O. .Ucc Contents Copyright. 1945 by Radrratl Publication. Inc. Text and Illustrations must not be reproduced without Write today for Bulletin IN -3, which pet lllissi7nt of COPY t ight t ,J.