Radio broadcast .. (1922-30)

WILLIS KINGSLEY WING Editor HOWARD E. RHODES . . Technical Editor EDGAR It. FELIX . . . Contributing Editor RADIO BROADCAST PUBLISHED FOR THE RADIO INDUSTRY VOL. XVI. NO. 5 Contents for March, 1930 Review ------------ -W. K. W. 251 Important Events Distribution New Models Broadcast Advertising In Lawyerland New Tubes? Revelation The Service Gospel A B.C. to A.C. "Converter" - Frank G. Ijogan 232 Characteristics of Pentode Tubes Keith Henney and Howard E. Rhodes 251 Automobiles With Radio - 256 The March of Radio -An Editorial Interpretation 258 The Jellyfish Commission "A Patent Pool for Public Service" Volume Control in Rroadcasting - O. B. Hanson High-Frequency Measuring Equipment - H. D. Oakley Magnetic Circuit Design E. A. Uehliny "Radio Broadcast's" Engineering Review Sheets - No. 31. Radio Galvanometers No. 32. Radio Galvanometers (continued) The Serviceman's Equipment - J'. H. Miller Three Years With the Federal Radio Commission Louts G. Caldwell - - Technical Shorts 260 262 265 267 269 Strays From the Laboratory - Square-Law Detectors Capacities of Coils Changes in Stations Production Testing Equipment Rating Radio Receivers Tricks With Set Testers Professionally Speaking Regarding Pentode Articles Are Technical Salesmen Needed? 270 273 Quartz Crystals A Correction Recent Articles of Interest J. A. Callanan 274 Alfred H. Grebe 276 Herbert M. Isaacson 278 Keith Henney 281 Improvements in Monitoring Getting Acquainted With A K PoinU on Installation The Serviceman's Corner - 284 Artifical Q R N 245 Tubes in Radiolas Sales Dope for Servicemen "Radio Broadcast's" Service Data Sheets - 288,290 Crosley Models 40S, 41S, 42S, 82S The Erla Model 224 Book Review - - - Robert S. Kruse 291 News of the Radio Industry 294 In the Radio Marketplace - 298 Radio Broadcast Laboratory Information Sheets Howard E. Rhodes No. 328. Loud Speaker Bibliog- raphy No. 329. Loud Speaker Bibliog- raphy No. 330. Loud Speaker Bibliog- raphy No. 331. Modulated Oscillator and Output Meter No. 332. Modulated Oscillator and Output Meter 300, 302, 304 No. 333. Calculating Power Out- put No. 334. Calculating Power Out- put No. 335. Undistorted Output tw. Dynamic Ran^e No. 336. Undistorted Output vs. Dynamic Range among other things FRANK G. LOGAN, who describes the Ward Leonard "Adaptoron" in this issue has been connected with the radio division of the company for many years. Mail reaches him at Mt. Vernon, New York. . . . O. B. Hanson, writing on volume levels in broadcasting, has been active in the technical side of broadcasting since "way back when." Mr. Hanson was with WEAF when its towers dominated 24 Walker St., New York, followed its fortunes to 195 Broadway, and when the National Broadcasting Company took WEAF unto its heart from the Telephone company, Mr. Hanson was made man- ager of plant and operations. . . . Edwin A. Uehling's article on magnetic circuit design in this number is one of those unusual articles which you may expect to find in RADIO BROADCAST. Mr. Uehling is a graduate of Wis- consin and has been with the Bell Laboratories, Grebe, and Fada. He is now in the Graduate School, University of Michigan. . . . For the past five years, H. D. Oakley, while he has been employed by General Electric, has l>een engaged in the invention and development of high- frequency measurement apparatus. Associated with Mr. Oakley are H. J. Schrader and G. S. Jacobs. Their enthusiastic interest and ability for this sort of work is responsible for much of the advancement which has been made in the creation of measurement tools and technique, Mr. Oakley tells us. /TT IN APRIL, the story about phonograph record- *\ changing mechanisms by Thomas Piazze, promised for this issue, will appear. Other articles will include: E. L. Brown, aircraft radio development; Jesse Marsten, high-frequency response; Von Ardenne, use of the cathode-ray tube to measure percentage of modulation; Mancill, describing construction of a laboratory and testing apparatus used; Oakley, input and output audio-frequency measuring apparatus; and an article from American Bosch describing the design and charac- teristics of their automobile radio receiver. All the regular departments for service and practical workers will appear, as usual. THROU(}H ONE of those often unexplicable and always embarrassing typographical errors, the formula appearing in the article by Ernest Amy and J. G. Aceves on page 206 of our February issue was made to read /TF- This, as most readers know, should 1 TERMS: $1.00 a year; single copies 35 cents; All rights reserved. Copyright, 1930, in the United States, Newfoundland, Great Britain, Canada, and other countries by DOUBLEDAY, DORAN & COMPANY, INC., Garden City, New York MAGAZINES . . . COUNTRY LIFE . . 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MCNAUGHTON, Asst't Treasurer 248 RADIO BROADCAST FOR MARCH