Radio Broadcast (Nov 1926-Apr 1927)

326 RADIO BROADCAST ADVERTISER radio ?n$mk Get Your Complete Parts for All the Newest Circuits Here In every issue of Popular Radio and other radio magazines you will find the newest circuits of the world's greatest radio engineers. You will want to build these sets from the parts specified. BARAWIK service keeps up to date on all the new wrinkles. We have the specified parts for all these new circuits, complete, ready to ship you the instant your order arrives. Take advantage of this unequalled service. Get what you want — quick — at a big saving. No order too large or too small for us. 300,000 fans swear by BARAWIK service. We can please you, too. Short Wave EquipmentSpecial Amateur Section The Barawik line features this season a special Amateur Department in charge of F. J. Marco, owner of station 9ZA, a nationally famous radio engineer and an authority on amateur work. It presents the latest in short wave equipment, transmitting and receiving supplies and everything necessary for the amateur and experimenter. Special attention has been given to short-wave kits including the B-T, Aero Coil, Silver-Marshall R.E.L., etc. It will pay you to get our new Guide at once. Radio's Newest at RockBottom Prices The new 1927 edition of the Barawik Catalog and Guide gives a comprehensive listing of the radio sets, parts, kits, supplies and accessories necessary in radio. This new guide contains over 6,000 items of radio's newest developments, everything that a real fan will need from the complete factory-built set to the smallest screw, including labor-saving devices, tools, power supply units, amplifier equipment, etc. Standard equipment of the best known manufacturers at tremendous savings. Besides the complete radio and amateur line there is shown a selection of electrical goods, household appliances, auto accessories and articles necessary in the home — all at a big saving in price. Write to-day for your free copy of the 164-page guide. Also please include name of other fans. Mail the handy coupon NOW. 540-549 Monroe St. Chicago, U. S. A. Mail This Coupon Now! For Free Copy Name . . Address ! Fan . . . S Address ■«■•■■■ i Bradkwmeter THE PERFECT POTENTIOMETER > Uses graphite disc resistors which are noiseless and not affected by atmospheric conditions. Metal parts are nickel plated. One hole mounting. Finish | and knob match' Bradleystat. Made in 200 and 400 ohm ratings <APsn-Bia%r Co. * ■ Electric Controlling Apparatus 278Greenncld Avenue Milwaukee, Wis. XVII, Induced Currents (with generators, commutators, series, shunt and compound windings, starting resistances, induction coils, telephones, featured in the text); Chapter XVIII, Alternating Currents; Chapter XIX, Sound (wave motion, musical tone, pitch, timbre); Chapter XXIII, Electric Waves (oscillatory discharge, vacuum tube detectors); and Chapter XXIV, Radio Broadcasting. Favorable as our comment is as to the value of this book to the radio enthusiast, we warn him that it is not a radio book. Just as the authors have confined themselves to basic principles in every branch of mechanics, optics, and acoustics, so also have they dealt with our beloved subject of radio. For example, we challenge you to understand the functioning of a vacuum tube clearly from a reading of the author's description. Everything there is true. But the student may ask after reading it, " What is the B battery for?" Perhaps the diligent reader may remember a statement, earlier in the book, that "electric current flows downhill from plus to minus in outside circuit." That would only confuse him, however, because the explanation says "the filament, when glowing, emits electrons" and they flow "from the filament to the plate." In the next chapter, it says that the B battery always keeps the plate positive. It would not be impossible to conclude from these statements that the B battery opposes the flow of electrons from the filament to the plate. The real error does not lie in the text; it is the fact that plus and minus signs were arbitrarily placed on dry cells long before anything was known about flow of electrons through vacuums. Early investigators simply got the signs the wrong way around. Nevertheless, these are minor points which do not detract seriously from the value of this comprehensive textbook of physics. Edgar H. Felix. Announcers' Biographies THE AMERICAN ANNOUNCER AND RADIO LOG: Published by the American Announcer, Buffalo, New York, 76 pages, 112 portraits. Price $2.50. ACCORDING to the publisher, it is intended that the purpose of The American Announcer and Radio Log be to bring the various fine broadcasting stations of the country nearer to the hearts and homes of the listener. The book is a fairly complete compilation of the biographies of some of the leading station announcers in the country. While perhaps all of the announcers can never be listed, the publishers are fully aware of the fact, but have made provision for the insertion of new pages when these are warranted. A photograph of each announcer is given, together with a brief sketch of his life and history before he became an announcer. To those who are interested in tracing back the influence which made their favorite announcers take up the profession, this information would be of particular interest. The station call letters, the owner, the power, and wavelength of the station are also given. With the physical dimensions, color of eyes, j and hair, any ardent announcerworshipper can certainly get a pretty good idea of his favorate idol. The latter pages of this book offer a list of stations, accurate at the time of publication with room for additions as the need may arise. The log gives the call letters, the owner, the location, the wavelength, the power, and three columns for marking down the dial settings. To supplement this list, the stations are regrouped according to their locality, and ready reference maps are provided for locating the stations. Cuban and Canadian stations are also listed. Cable Connector ring for Binding Posts You will get some real satisfaction and pleasure, too, with the Yaxley Cable Connector Plug. It does away with a mass of unsightly wires and concentrates them in one neat, compact unit. Cable Connector consists of plug and receptacle. The plug is provided with seven 15-inch strands (RMA Standard Colors) which connect directly to the binding posts. The receptacle is provided with 5-foot seven-strand cable for connecting to the batteries. Plug and receptacle are of Bakelite, with phosphor bronze contact springs and brass pins. A sure, positive contact is assured, and because of the guide pin it is impossible to put the Connector together incorrectly. Increase the pleasures of your radio hours by getting one to-day. No. 670 — Cable Connector Plug .... $4.00 At your dealer's. If he cannot supply you send his name with your order to YAXLEY MFG. CO Dept. B, 9 So. Clinton St Chicago, 111. ^ This is a good time to subscribe for RADIO BROADCAST Through your dealer or direct, by the year only $4.00 DOUBLEDAY, PAGE & CO. GARDEN CITY, NEW YORK Type 612— $42.50 The "<B" Without a 'Buzz Also — Complete set of parts for homebuilders at reasonable prices. Write us. M A Y O L I A N RADIO CORPORATION 1 668 Webster Ave., New York. N. Y. 'Pioneers in 'Battery Elimination ★ The Tower of Niagara — The S^uiet of an oArctic ^Night if Examined and approved by Radio Broadcast if