Radio broadcast .. (1922-30)

RADIO BROADCAST ARTHUR H. LYNCH, Editor WILLIS K. WING, Associate Editor JOHN B. BRENNAN, Technical Editor JANUARY, 1926 Vol. VIII, No. 3 Cover Design From a Painting by Fred }. Edgars Telephoning Photographs *•*'**. Frontispiece Ether Waves You Cannot Hear James Stotyey Late News on the International Tests Willis K. Wing The March of Radio J. H. Morecroft What's New in Radio Austin C. Lescarboura Better Audio Amplification Kendall Clough Notes on the Model 1926 Receiver Ernest R. Pfaff The Listeners' Point of View John Wallace A Universal Short' Wave Transmitter Nicholas Hagemann As the Broadcaster Sees It ' Carl Dreher "Radio Broadcast's" Universal Receiver Arthur H. Lynch "Radio Broadcast's" Booklet of Call Signals Lawrence W. Corbett Methods of Controlling Oscillation in Radio Fre' quency Circuits John Bernard If You Seek Economy, Buy the Best Harold Jolliffe "Now, I Have Found" ' An A. C. Amplifier with the Robert! The Roberts Set with Cylindrical Coil* A Home-Made Loud Speaker The Grid — Questions and Answers •»'•**» Component Values for the "Aristocrat " Noises and Their Causes Impedance Amplifiers A Key to Recent Radio Articles E. G. Shaltyiauser Book Review *.••'_• J. H. Morecroft "RADIO: BEAM A>{D BROADCAST" High-Speed Fading ' What Our Readers Write Us ........ 295 299 300 305 308 313 317 321 326 332 337 350 360 362 376 380 388 392 394 EDITORIAL SCENES TAMES Stokley. who writes "Ether Waves You Cannot I Hear" is an associate of Dr. Edward E. Slosson, the director of Science Service in Washington. Science Service is a most interesting and unusual organization, devoted to presenting in an able fashion the facts about science in any of its branches. The board of directors of the organization number some of the greatest scientists now living in America. For the benefit of those readers who do not know, Professor J. H. Morecroft whose "March of Radio" has appeared in RADIO BROADCAST ever since its first issue is a professor of electrical engineering at Columbia University, where he has trained many a radio engineer. Austin Lescarboura, the writer of'What's New in Radio" was formerly Managing Editor of the Scientific American. He is now a free lance writer. Some interesting slants — as the baseball writers put it — on broadcasting are offered by the new conductor of "The Listeners" Point of View," John Wallace, whose first department appears in this number. The changes in call letters, and frequency of Canadian and American broadcastings tations during the past few months have been many and we have made every effort to have the list appearing on page 337 the most accurate to be found anywhere. Readers who have access to a razor blade and a pin can quite easily make up a sixteen-page booklet from the list. Some misunderstanding has arisen about the description of a new N-P coil for the Roberts Knockout receiver printed on page 66 of RADIO BROADCAST for November. The author was Ralph D. Tygert, an engineei on the staff of the F. W. Sickles coil company at Springfield, Massachusetts. Mr. Tygert's findings have been incorporated in the new coils now being marketed by that company for the Knockout receiver. OCTOBER and November have been the months of radio shows throughout the country; November especially was a red letter month in American radio affairs, for the third of Secretary Hoover's radio conferences was held in Washington and everyone agrees that the policies recommended for radio are most wise and calculated for the best interests of radio in this country. Too much credit can not be given to Mr. Hoover for his ability and foresight in causing the varied and sometimes sharply competitive interests of radio to settle their complex problems by amicable conference where reason has almost always prevailed. MUCH activity is seen in the Laboratory these days. The staff is experimenting with three distinct receiver circuits, all of which have great merit and technical interest. If the receivers are proved worthy, each one will be described in an early number of the magazine. The Laboratory is collecting data on radio tubes and Keith Henney, director of the Laboratory, will have an article showing curves on all the popular tubes with a mass of highly valuable information for every radio user, which, as far as we know, has never been put together in one article before. The February number will also present "How Long Will My B Batteries Last?" by George C. Furness, an engineer who probably knows as much about radio batteries as anyone in the business. We shall also give the latest plans for the 1926 International Radio Broadcast Tests which will occur one week after the February magazine is on sale. Those Tests, by the way, give promise of being more interesting and successful than either of the two which have so far been held.— W. K. W. Doubleday, Page & Co. MAGAZINES COUNTRY LIFE WORLD'S WORK GARDEN & HOME BUILDER RADIO BROADCAST SHORT STORIES EDUCATIONAL REVIEW LE PETIT JOURNAL EL Eco THE FRONTIER WEST Doubleday, Page &• Co. BOOK SHOPS /LORD & TAYLOR BOOK SHOP I PENNSYLVANIA TERMINAL (2 Shops) . < 3g WALL ST \GRAND CENTRAL TERMINAL f 22^ NORTH 8™ STREET \ 4914 MARYLAND AVENUE K .,.-, CITY I 920 GRAND AVENUE KANSAS CITY, j ?o6 WEST 4?TH STR£ET TOLEDO: LASALLE & KOCH CLEVELAND: HIGBEE Co. SPRINGFIELD, MASS.: MEEKINS, PACKARD & WHEAT »._„, NEW ST Louis Doubleday, Pjfe & Co. OFFICES GARDEN CITY, N. Y. NEW YORK: 120 WEST 32ND STREET BOSTON: PARK SQUARE BUILDING CHICAGO: PEOPLES GAS BUILDING SANTA BARBARA, CAL. LONDON: WM. HEINEMANN LTD. TORONTO: OXFORD UNIVERSITY PRESS Doubleday, Page &" Co. OFFICERS F. N. DOUBLEDAY, President A. W. PAGE, Y ice-President NELSON DOUBLEDAY, Vice-President RUSSELL DOUBLEDAY, Secretary S. A. EVERITT, Treasurer JOHN J. HESSIAN, Assi. Treasurer Co, DOUBLEDAT, PAGE & COMPACT, Garden Qity, ^e jpyright, 1925, m the United States, Newfoundland, Great Britain, Canada, and other countries by Doubleday, Page & Company. All rights reserved. TERMS: $4.00 a year; single copies 35 cena. 29O