Radio Broadcast (May 1928-Apr 1929)

21 B2B ©C1B789803 radio Broadcast JUNE, 1928 Willis Kingsley Wing, Keith Henney Director of the Laboratory Editor Edgar H. Felix Contributing Editor Vol. XIII. No. 2 QOTiTET^TS Cover Design From a Design by Harvey Hop\ins Dunn Frontispiece . , . In the Grand Canyon of the Colorado How Chain Broadcasting Is Accomplished ' ' ' ' C. E. Dean The March of Radio ' An Editorial Interpretation Broadcasting Needs Capable Leadership Mergers in the Radio Industry More High Power Broadcasting British Skeptical of Baird Television Accomplishments Present Distribution of Broadcast Stations Here and There Automatic Tuning for the Radio Receiver The Newest Power Tube ' * Book Reviews Leroy S. Hubbell Howard E. Rhodes Carl Dreher Lefax Radio Handbook Radio Engineering Principles, Lauer and Brown A Popular Guide to Radio, Dashiell The "Cornet" Multiwave Receiver From Milliammeter to Multi-Meter "Strays" from the Laboratory W. H. Wenstrom G. F. Lamp\in Output Transformer Characteristics High Powered Press Releases A.C. Troubles May Standard Frequency Signals Short-Wave Notes Recent Interesting Contemporary Articles Another Useful Publication Radio School Scholarships New Apparatus Useful Information on Js[eu> Products A Screen-Grid Booster for Any Receiver Glenn H. Browning Our Readers Suggest An Emergency Detector B Supply Some Baffle-Board Experiments Emergency and Experimental Connections Antenna Tuning Device Volume Control for Resistance-Coupled Am A Spark Plug Lightning Arrester plifiers "Radio Broadcast's" Service Data Sheets on Manufactured Receivers ' No. 1. The Amrad A.C. 7 No. i. The Pfansteihl A.C. 34 and 50. Building and Operating the A. C. "R. B. Lab" Receiver Hugh S. Knowles Using the Screen-Grid Tube in Popular Circuits Laboratory Staff A Good Crystal Receiver for the Beginner Keith Henney A Three-Tube A.C. Operated Roberts Receiver Elmer G. Hery As the Broadcaster Sees It Carl Dreher The Simplest Receiver Design and Operation of Broadcasting Stations: 20. Field Strength Measurements How Can Good Radio Programs Be Created? The Listeners' Point of View The Month's New Phonograph Records "Radio Broadcast's" Directory of Vacuum Tubes Manufacturers' Booklets "Radio Broadcast's" Laboratory Information Sheets No. 193. Motorboating No. 194. Push-pull Amplifiers No. 195. A Resistance-Coupled Amplifier with Screen-Grid Tubes No. 196. Circuit of a Resistance-Coupled Screen-Gtid Amplifier The Haven of a Sea-Going Audion No. 197. Amplification Constant No. 198. The Screen-Grid Tube as an R.F. Amplifier No. 199. Current No. 200. Resistors The contents of this magazine is indexed in The Readers' Guide to Periodical Literature, which is on file at all public libraries. 64 65 72 74 76 77 80 83 85 87 89 9i 93 96 97 99 102 John Wallace 104 106 107 108 110 Raymond Tr avers 116 AMONG OTHER THINGS. IT HAS not been possible to reply with a personal letter to each of our readers who filled out and returned the readers'1 questionnaire recently sent many of those who are regular subscribers. The desires and opinions of readers expressed have been very helpful. Many interesting conclusions are at once apparent. Our policy of giving complete information about the manufactured parts described in constructional articles is overwhelmingly approved. The type and form of the articles dealing with the construction of apparatus — such articles as those in this issue for example — are welcomed. The many special features and articles which distinguish Radio Broadcast from its contemporaries are especially praised. SOME readers who have read elaborate statements of policy appearing in some of our contemporaries have asked us, in effect, if we were going to announce a changed policy, too. All we have to say about the editorial policy of Radio Broadcast' has been said in this column in the May issue. This magazine is edited for the reader and what he finds in Radio Broadcast is information — lots of it, as interestingly, as completely, as accurately presented as we know how. This magazine will neither be full of inconsequential and slightly sensational articles about the marvelous potentialities of radio nor will it overflow with constructional articles on every possible subject having the apparent purpose of merely using the products of a selected group of radio manufacturers. Our policy of making each article complete in itself and not "continued on page 96" is still in force. The special sections which have so wide a following: the Laboratory Data Sheets, the March of Radio, Strays from the Laboratory, Our Readers' Suggest . . . , As the Broadcaster Sees It, the Service Department, are to be continued. With this issue, we introduce a new regular feature: "Radio Broadcast's Service Data Sheets on Manufactured Receivers" which present all essential data on various makes of sets now in use. Several other important new features are in the course of preparation. "POGAR H. FELIX, contributing editor, attended the pub-1— ' lie hearings before the Radio Commission April 23 and 24. He appeared as an expert witness and presented the suggestions for the solution of the broadcasting problem which have attracted such wide attention in our editorial section, The March of Radio. Incidentally, we are told that Mr. Felix's May article "Will New Transmitting Methods Be the Remedy?" is accepted in Washington as the most clear and fair presentation of the difficulties and possibilities for solution of the present broadcast situation. OUR July issue promises many interesting features. There is an excellent non-radiating short-wave receiver using a screen-grid tube, a searching analysis of the almost overwhelming obstacles to practical television, the description of a fine B supply and power amplifier using the 250 type tube, a practical set tester, and many other articles, selected because of their unusual interest. — Willis Kingsley Wing. VOUBLED AT, DORAN & COMPACT, LNC Garden Qity, Hew Tor\ MAGAZINES Country Life World's Work Garden & Home Builder Radio Broadcast Short Stories Educational Review Le Petit Journal El Eco Frontier Stories West The American Sketch BOOK SHOPS (Booh of all Publishers) [ Lord & Taylor; James McCreery & Company j Pennsylvania Terminal and 166 West 32ND St. New York:-; 848 Madison Ave. and 51 East 44TH Street I 420 and 526 and 819 Lexington Avenue Grand Central Terminal and 38 Wall Street Chicago: 75 East Adams Street St. Louis: 223 N. 8th St. and 4914 Maryland Ave. Kansas City: 920 Grand Ave. and 206 West 47TH St. Cleveland: Higbee 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. Toronto: Oxford University Press OFFICERS F. N. Doubleday, Chairman of the Board Nelson Doubleday, President George H. Doran, Vice-President S. A. Everitt, Vice-President Russell Doubleday, Secretary John J. Hessian, Treasurer Lillian A. Comstock, Asst't Secretary L. J. McNaughton, Asst't Treasurer Copyright, 1928, in the United States, J^eif/oundland, Great Britain, Canada, and other countries by Doubleday, Doran & Company, Inc. All rights reserved. TERMS: $4.00 a year; single copies 35 cents. 62