Radio Broadcast (May 1928-Apr 1929)

308 RADIO BROADCAST ADVERTISER Render's Tone • lriumpH This new Audio system gives Set Builders a tremendous Advantage/ rrlURN the volume conJL trol of your set down to a whisper .... if you lose the bass notes — you know the audio-system is not what it should — and can — be. There is a loss of tones — vital to modern reception. 'T'HE Remler Laboratories — identified with J. the big developments in radio for over ten years — have perfected a new audiosystem that brings radio reception to new standards of excellence. Based on the proved and practical principle of Resonated Windings— applied in a new and simple way fully explained in our instructions— the Remler Audio-Transformer Team. Nos. 92(1-921-923, give a high gain and undisputed power output that is absolutely unequalled in any other system. In conjunction with a Dynamic Type Speaker— the Rembler AudioTransformer will give your set a full, undistorted tone quality that is as superior to former reception as the modern phonograph is to the old time graphaphone. Six new Audio-transformers No. 920. Resonated Primary, first stage, 4% to 1 ratio $12.00 No. 921 Second Stage, 6V2 to 1 ratio. $12.00 No. 923. Output impedance compensating Transformer $20.00 No. 900. Resonated Primary, first stage 3% to 1 ratio $8.00 No. 901. Second Stage, 3% to 1 ratio. $8.00 No. 922. Output Transformer $10.00 Delivery about September 1 REMLER ™ Division of ™ GRAY & DANIELSON MANUFACTURING COMPANY 260 First Street CHICAGO San Francisco NEW YORK ---- - Send for Remler Literature-"——--—™ R. B. 9. REMLER Division of GRAY & DANIELSON MANUFACTURING CO. 260 First St., San Francisco, Calif. Please send me I ] Literature about new parts. [ J Bulletin Service for Professional Set Builders. Name Address City State Do you build and sell sets? :iirn< 1 Letters from Readers Our Latest Departures CEVERAL recent additions to the editorial ^ contents of Radio Broadcast have brought forth comment from many sources. We are happy to feel that our innovations are worthy of response, and want to get as much of it as we can — both favorable and adverse. Here's some from Mr. Lewis S. Maxfield, of Brooklyn, N. Y. To the Editor: Allow me to express my appreciation for the series of articles entitled "Home Study Sheets" beginning on page 135 of the July issue. This is something that has been long wanted and I am pleased to see that my favorite magazine is to publish same. Let us have more of the science and physics side of radio and less knocking of programs, which after all are free and if you don't like them don't listen. Mr. Maxfield is an engineer and physicist. Here's what an amateur thinks — Sherwood J. Beutler, of Buffalo, N. Y. (8-ht) To the Editor: I wish to commend you upon the interesting technical articles you are publishing in Radio Broadcast, particularly your introduction of the "Home Study Sheets"; also the addition of Mr. Robert S. Kruse to your engineering staff. I have been active in the amateur and laboratory development of radio for the past ten years, during which time I have reviewed many radio magazines, but for clear, reliable technical data I believe Radio Broadcast rates the highest of them all. Unfortunately, we can't exactly claim Mr. Kruse as a member of our engineering staff, but there are a great many more articles that he is cooking up for future issues. Incidentally, some of the answers to the problems in the "Home Study Sheets" are making the Laboratory Staff sit up and take notice in regard to such details as neatness, clarity, and general excellence of arrangement. Our Mistake LARING mistakes have occurred in every form of printed matter known, from the famous "Wicked Bible" to the modern tabloids. Here is one from the July issue of Radio Broadcast, in Mr. Messenger's article on the universal set tester. Among others, VV. D. Wollaver, Wattertown, N. Y. has written to us about it. To the Editor: In your July issue [Page 149] you had an article on a three meter tester and gave a diagram of the same. I have started building the tester, but have run up against something which seems incorrect. The minus terminal of the socket has no connection in the diagram. I have not tried to work the circuit on my own hook, as I thought there should be a connection on the terminal. I would greatly appreciate your help on this. Mr. Messenger himself caught the error and telegraphed that the connection should go from the minus terminal on the tube socket to the minus lead from the plug on the cable. The American Mercury recently offered a salary of a million dollars a year to an infallible proof reader. All the applicants for the job were refused, because in the very paragraph in which the offer was made there was a typographical error which none of the applicants caught. And it wasn't a trick! We are in the same boat with the Mercury. After checking, rechecking, and (Continued on page 316) Jenkins & Adair Condenser Transmitter For Broadcasting, Phonograph Recording, and Power Speaker Systems rT,HIS transmitter is a small condenser which J varies its capacity at voice frequency, and is coupled direct, into a single stage of amplification, contained in the cast aluminum case. The output, reduced to 200 ohms, couples to the usual input amplifier. The complete transmitter may be mounted on the regulation microphone stand. It operates on 180 v. B and 6 or 12 v. A battery. This transmitter contains no carbon, and is entirely free from background noise. Its yearly upkeep is practically nothing. It is extremely rugged, and will withstand hard usage. Price, complete with 20 ft. shielded cable, $225.00 F.O.B. Chicago. J. E. JENKINS & S. E. ADAIR, Engineers 1500 N. Dearborn Parkway, Chicago, U. S. A. Send for our bulletins on Broadcasting Equipment NATIONAL TUBE REPAIRS During our long period of experimentation and development, we have always maintained a money back guarantee and we have SURVIVED. This means that we are putting honest effort into our Products and that we merit your orders. We List and Price Repairs W. E. 211 W. E. 212 U. V. 203A U. V. 204A U. V. 204 $16.50 40.00 19.00 75.00 50.00 (10% Discount on lot of 6 tubes, from above list) These tubes are rebuilt using same type filament as they had originally; also the operating characteristics are maintained the same. We purchase burnt out tubes of the above types. SOLVE your rectifier troubles once and for all. RECTOBULBS 3000 Volts and 250 Mils. $ 1 5 ea. Type 203 50 Watt Tube $20 ea. No charge for crating if cash accompanies order. Our work guaranteed against defects of material and workmanship. National Radio Tube Co. 3422 18th St., San Francisco, Calif. (A Ham Institution)