Radio today (Sept 1935-Dec 1936)

Ourtype"H" 40 watt Mica Card units have been subjected, in laboratory tests, to loads up to 120 watfs without injury. Size 1J4" wide, 334" long by 3^" thick. Theirunique construction suggests many uses. 200% Overload Without Injury with MICROHM MICA CARD RESISTORS Write for further information and our new catalog. PRECISION RESISTOR COMPANY 334 Badger Avenue Newark, N. J. 0Tfl1(Sl3®MO WIRE WOUND RESISTORS lay's Radio Tad* BOOK SHOP FOR the convenience of our readers in obtaining Radio Books, we offer the services of this department. Outstanding Radio Books will be advertised monthly. These are available to you at the prices listed. No charge will be made for wrapping and mailing. Should you desire a book that we have not yet advertised, and the price of which you do not know, just send $5 with your order and we will return the correct balance, or communicate with you if the list price exceeds that amount. Address : BOOK SHOP, RADIO TODAY 480 Lexington Avenue, Xew York, X. Y. Radio Trouble Shooting, by E. R. Haan. Takes the guess work out of Radio. Shows the service man quickly and efficiently exactly what is wrong with an inefficient set and how to correct the trouble. 32S pages, over 300 illustrations.$3.00 The Outlook for Television, by Orrin E. Dunlap, Jr. In this volume a leading student of broadcasting and television gives you the latest information on the subject and offers, in addition, the ideas of eight foremost authorities on the value of television in their individual fields.. §4.00 The Advertising Agency Looks at Radio, Edited by Neville O'Neill. Get the first detailed and comprehensive statement of the Advertising Agencies' point of view on Radio from IS experts. 248 pages $3.00 SOS to the Rescue, by Karl Raarslag. Th stirring narrations of great sea disasters and rescues — such as the "Titanic" — "Vestris" — "Morro Castle" — all from the Radio Operators' viewpoint. 16 illustrations $2.50 Loud Speakers — Theory, Performance, Testing, and Design, by N. W. McLachlan. Fully equipped with tables of experimental data. 1G0line diagrams and photographs $13.30 Elements of Loud Speaker Practice, by N. W. McLachlan. A small, practical manual. Covers the entire field of practice excepting some theoretical and advanced aspects, illustrated with simple diagrams $1.75 Experimental Radio, by Prof. R. R. Ramsey. Revised Edition. Comprises 12S experiments 229 pages, 150 illustrations $2.73 The Fundamentals of Radio, by Prof. R. R. Ramsey. New Second Edition. Revised. Enlarged. An up-to-date, authoritative, exposition of the principles underlying the many phases of Radio. 426 pages, well illustrated $3.50 Your Invention — How to Protect and Merchandise It, by Elmore B. Lyford. Plain facts on Patents, Trademarks, and Copyrights. Explains how to completely protect your ideas — and how to patent them. Includes 24 legal forms 210 pages bound in cloth $1.50 Applied Acoustics, by Harry F. Olson, and Frank Massa. A textbook and reference manual covering the theoretical and experimental aspects of electro-acoustical systems. The first American book dealing entirely with acoustical engineering principles. 430 pages, 228 illustrations. . .$4.50 Radio Physics Course, by Alfred A. Ghirardi. 2nd Revised Edition. Basic electrical theory pertaining to the latest applications. Used the world over as a valuable reference and text book. Nearly 1,000 pages. 500 diagrams and illustrations $4.00 Aircraft Radio, by Myron F. Eddy. A complete guide to the principles, selection, installation, operation, and maintenance of Aircraft Radio 284 pages, 68 diagrams and illustrations . . $3.00 Principles of Radio Communication, by John H. Morecroft. Completely revised to conform with modern developments of the art and science of Radio. One of the recognized standards on theory. 1,084 pages. Cloth $7.50 Elements of Radio Communication. by John H. Morecroft. Contains more simplified material than the "Principles of Radio Communication, by the same author. Not a condensed edition of the "Principles," but an entirely new and independently written volume. 286 pages. ' loth $3.00 Experimental Radio Engineering. by John H. Morecroft. 51 experiments covering the entire range of Radio. 345 pages. Cloth. $3.50 Principles of Radio, by Keith Henney, In tended primarily for radio students, experimenters, and technicians — this book covers a wide range of subjects from the fundamentals of electricity to the modern concepts of modulation and detection. Well illustrated. Practical. 491 pages Cloth $3.30 Radio Round the World, by A. W. Haslett. Tells what wireless waves are. How they travel round the world ; and how the sun helps them on their way. Their world-wide applications in television, medicine and communication. 192 pages $1.75 The Rise of Radio — The Electric Word, by Paul Schubert. An interesting narrative of the rise of radio, and how the interplay of science, business, politics and diplomacy have accompanied its development. 311 pages $2.50 The Story of Radio, by Orrin E. D-unlap, Jr New, revised, enlarged edition. 32 illustrations. The recent strides in television, photoradio, ultra-short waves, and in radio applications in man's fight against body ailments have led to this expansion of The Story of Radio, which should be on your bookshelf $2.75 Order Your Radio Books From BOOK SHOP, RADIO TODAY 480 LEXINGTON AVENUE NEW YORK, N. Y. ELECTRONICS "Frequency-modulation" on 7-meter band * Signs of a coming revolution in the broadcasting art — if broadcasting goes to the ultrashort waves — are now clearly visible to some engineers who have examined Major E. PI. Armstrong's wide-band "frequency-modulation" system. This system, which is operating between the Empire State Building in New York and Haddonfield, X. J., near Camden, is giving a better signal in Haddonfield than the 50 kw. New York stations. The superiority in freedom from static and tube noise and the entire absence of selective side band fading at a distance well beyond the fading zone, have been demonstrated repeatedly during a summer which has been marked by thunderstorms of great severity. On numerous occasions it has been shown that the 2 kw. 7-meter Empire State signal is far better than the high-power Philadelphia stations. The new system employs frequency shifts as wide as 60 kilocycles. The overall frequency characteristic of the transmitter and receiver is declared to be flat from 30 to 20,000 cycles, which accounts for the high fidelity of the transmission. The system is being successfully used for multiplex transmission of programs. Electronic bull's-eye for Lake Placid gunners * When the Statewide Rod and Gun Club meets at Lake Placid, K". Y., in mid-September, a new photo-electric "gun" that shoots light instead of bullets, will be demonstrated. In the target is a photoelectric cell, or "electric eye." When the trigger is pulled, a focussed light in the gun-barrel flashes momentarily. If the light-beam is aimed at the photo-cell bull's-eye at that instant, the photo-cell records a hit, sending its own faint electronic impulse through amplifiers to ring the gong. At the same time a big red light is switched on with each bull's-eye rung up. Similar photo-electric targets have been tested out by U.S. Army officials in an effort to develop a gun for target practice that requires no ammunition and will save Uncle Sam's money. 54 Radio Today