Radio broadcast .. (1922-30)

RADIO BROADCAST DECEMBER. 1928 KEITH HENNEY Director of the Laboratory WILLIS KINGSLEY WING, Editor EDGAR H. FELIX Contributing Editor HOWARD E. RHODES Technical Editor Vol. XIV. No. 2 *^> i Cover Design - - - From a Design by Harvey Hopkins Dunn Frontispiece - - Old Saywlle Station Returns to Limelight 84 Quartz Crystals R. C. Hitchcoc^ 85 Phonograph-Radio Amplifiers Howard E. Rhodes 88 The March of Radio An Editorial Interpretation 91 Radio, the Corner Stone of the Amusement With the Broadcasting Stations Industries The Progress of Aircraft Radio WCY Protests Allocation Plan Radio Abroad The joo-Mile Chain Regulation The Visual Broadcasting Field The Fight for Short Wavelengths News of the Radio Industry The "Skyscraper" Screen-Grid Receiver - - Clifford Denton 95 "Strays" from the Laboratory .,.,., Keith Henney 97 Accuracy of "Slide-Back" Voltmeters Data on Underground Aerials Hum in the "Lab." Circuit Receiver Type in Tubes in First Audio Stage A Test Set for the Radio Service Man - B. B. Alcorn 99 The Service Man's Corner - - 101 As the Broadcaster Sees It Carl Dreher ioa Information on Sound Motion Pictures Broadcast Standardization Some Experiments with Band-Pass Filters - - Kendall dough 104 "Radio Broadcast's" Home Study Sheets 107 No. ii. Resonance in Radio Circuits—Part I No. 11. Resonance in Radio Circuits—Part II Loud Speakers—A Debate - - 109 Removing Nonsense from Short-Wave Transmission Robert S. Kruse in "Our Readers Suggest— 114 An A.C. Screen-Grid Booster Push-Pull with Standard Transformers Work Table Clamp Home-Made Soldering Lug The New A.C. Screen-Grid Browning Drake Receiver Glen H. Browning 115 Book Reviews Howard £. Rhodes 116-125 An A.C. Band-Pass Screen-Grid Receiver— The Master "Hi-Qag" William E. Barton 117 New High-Voltage Metallic Rectifiers for B-Power Units /. George Uzmann 120 "Radio Broadcast's" Service Data Sheets - - - 121 No. ij. The A.C.-66 Dayton Receiver No. 14. The Fada Models 50, 70, 71 and 71 Problems in Synchronizing Television Receiving Discs Boyd Phelps 123 The "Chronophase" for A.C. Tubes - - - Bert E. Smith 126 New Apparatus and Their Applications - 127 Manufacturers' Booklets 128 "Radio Broadcast's" Laboratory Information Sheets - - 130 No. 141. Supplying Power Devices from 110 No. 146. Power Output Characteristics of Volts A.C. Tubes No. 141. Resistance-Coupled Amplifiers No. 147. Television No. 143. Resistance-Coupled Amplifiers No. 148. Frequency Characteristics of Tele- No. 144. Alternating-Current Ratings vision Amplifiers No. 14T. Power Output Letters from Readers 137 j Short-Wave Stations 141 The contents of this magazine is indexed in The Readers' Guide to Periodical Literature, which is on file at all public libraries. AMO7s[G OTHER THINGS. . . WITH this issue, we start the promised department for radio service men. The service man is a most important element in the present radio structure but for some reason or other he has been inarticulate. We know that a great many readers of RADIO BROADCAST are doing service work, either on whole- or part-time and we hope that those who are doing this work will write us, telling of their problems, how they are being solved, and of topics they would like to see discussed. Incident- ally, the head of one of the largest New York organizations specializing in this work, Mr. John S. Dunham, writes: that although he believes service articles are of real value that "the average service man could derive far greater benefit by pains- taking, thorough study of RADIO BROADCAST'S Data Sheets from the beginning and the very excellent series of Home Study Sheets, recently inaugurated. From our own experience, we believe that service men generally need to increase their basic knowledge." With this, we agree, but we are certain that the experiences of service men are of deep interest to others working in the field. It certainly goes without saying that no service man can really do his work intelligently unless he has a thorough background in fundamentals. THE application of power amplifiers, microphones, moving- coil loud speakers and similar apparatus for so-called public- or group-address work seems to be increasing rapidly. This de- velopment is a natural and fortunate one and in our opinion due largely to the increasing appreciation of what good radio ap- paratus can do. The question which most frequently comes up is not the simple one of how to connect or to operate the gear but what power output is essential for a given service. RADIO BROADCAST Laboratory Data Sheets Nos. 245 and 146 in this is- sue discuss this interesting question. EARLY in 1926, Mr. Howard E. Rhodes joined the staff of RADIO BROADCAST and since that time, his excellent articles have added much to the interest and technical value of our pages. The popular Laboratory Data Sheets are Mr. Rhodes' work. We are pleased to announce that effective November ist, Mr. Rhodes was appointed Technical Editor of this magazine. THE current issue contains many articles on subjects of great interest to many radio folk. Notable among these are the following: the article on cutting and grinding quartz crystals, the data on underground antennas in "Strays from the Laboratory," the references to sources of information on sound movies, the article on experimental band-pass filters, the dis- cussion of moving-coil and "magnetic" type loud speakers, Mr. Kruse's article on amateur experimenting and finally Boyd Phelps' description of his ingenious work in television synchron- izing which is found on page 123. THE January issue will contain the long-promised article on moving-coil speakers and is worth waiting for. Con- structional stories on interesting receivers, and power amplifier units are promised as well as more useful data for the experi- menter and service man. — WILLIS KINGSLEY WING. OOUBLEDAT, OORA^ & COMPACT, IA[C., Garden Qity, Hew MAGAZINES COUNTRY LIFE WORLD'S WORK THE AMERICAN HOME RADIO BROADCAST SHORT STORIES LE PETIT JOURNAL EL Eco FRONTIER STORIES WEST THE AMERICAN SKETCH BOOK SHOPS (Book! of all Publiiken) JLoRD & TAYLOR; JAMES McCREERY & COMPANY PENNSYLVANIA TERMINAL AND 166 WEST 32ND ST. 848 MADISON AVE. AND 51 EAST 44TH STREET 420 AND 526 AND 819 LEXINGTON AVENUE GRAND CENTRAL TERMINAL AND 38 WALL STREET CHICAGO: 75 EAST ADAMS STREET ST. Louis: 123 N. STH ST. AND 4914 MARYLAND AVE. KANSAS CITY: 920 GRAND AVE. AND 206 WEST 47TH ST. CLEVELAND: Hir.BF.E COMPANY SPRINGFIELD, MASS: MEEKINS, PACKARD & WHEAT OFFICES GARDEN CITY, N. Y. NEW YORK: 244 MADISON AVENUE BOSTON: PARK SQUARE BUILDING CHICAGO: PEOPLES GAS BUILDING SANTA BARBARA, CAL. LONDON: WM. HEINEMANN. LTD. OFFICERS F. N. DOUBLEDAY, Chairman of tke Board NELSON DOUBLEDAY, President GEORGE H. DOR AN, Vice-President S. A. EVERITT, Vice-President RUSSELL DOUBLEDAY, Secretary JOHN J. HESSIAN, Treasurer LILLIAN A. COMSTOCK, Asst't Secretary CoDjright, TORONTO: DCH'BLEDAY, DORAN & GUNDY, LTD. L. J. MCNAUGHTON, Assft Treasurer 1928, hi the United Slatei. Newfoundland, Great Britain, Canada, and other countries by Daubleday, Doran & Company, Inc. All rijhtj reserved. TERMS: $4x90 a year; single copies 39 cent*. 82