Radio Broadcast (Nov 1926-Apr 1927)

310 RADIO BROADCAST ADVERTISER THE BEST IN CURRENT RADIO PERIODICALS The Fifteenth Installment of a Useful Classified Survey of Material Appearing in the Radio Press By E. G. SHALKHAUSER How This Survey Can Help You J-JO W often have you looked for information contained in some article which you recall having *■ * read months ago — the description of the Browning-Drake receiver, or the measurement of losses in inductance coils, for example? After looking through probably several issues of a do%en different publications, you either give up or become interested in something altogether different. When data is wanted on some particular subject, a systematic file of subjects and titles becomes a real radio encyclopedia. Instead of having merely the title of an article given, which often is misleading, a summary of the contents gives all the information. These surveys cover the radio field as gleaned from material in to-day's periodicals. They will always serve as a future reference-guide to all who are interested in the science of radio, whether engineer, manufacturer, dealer, experimenter, or listener. To be of practical value and easily accessible, these surveys should either be pasted in a scrap book, or, better still, be pasted on individual cards and filed according to numbers, or alphabetically. In the matter of classification of articles, the Bureau of Standards circular No. 138 has been followed. This may be obtained from the Government Printing Office, Washington, District of Columbia, for ten cents. In addition, each abstract has certain key-words placed at the upper right, which may be used for the purpose of filing articles alphabetically. With this series of surveys we hope to aid our readers and help them through many difficulties which they no doubt have often experienced. The writer is prepared to give information and references to articles previously surveyed upon receipt of a stamped and self-addressed envelope. Following is the series of headings, made up according to the Dewey Decimal System used in the Bureau of Standards circular No. 138: Can't tun&om out? TRY a Micadon 601 in series with the antenna of your set, if you find it hard to "tune out" nearby stations. The Micadon will have the same effect as "loose coupling," and the selectivity of your set will be greatly improved. Capacities from .0001 to .0005 mfd. may be used — you will find a full explanation in our 32-page booklet, "Seventeen Ways to Improve Your Set." Micadons, because of the patented principles of low-loss insulation and protection against variation in capacity which they embody, are a vital element in the improved reception of thousands of radio sets. The tone, the efficiency, and the satisfactory operation of your set depend on the quality of the fixed condensers used. If you want to be sure that your set will do all it was meant to do, be sure that the fixed condensers bear the name of Dubilier. Send 10c in stamps or coin for your copy of "Seventeen Ways to Improve Your Set." Dubilier* CONDENSER, AND RADIO CORPORATION 4377 Bronx Blvd., New York, N. Y. Rooo Radio Communication in General. Under this heading will appear all subject matter pertaining to laws, regulations, history, publications, etc., which deal with radio in a general way. R100 Principles Underlying Radio Communication. Here will be given the phenomena of radio waves, their underlying theory of propagation, the principle of antenna and counterpoise, design and characteristics of vacuum tubes and their behavior in circuits, types of circuits, transmitting and receiving apparatus and their principles of operation. R200 Radio Measurements and Standardization Methods. The various known methods which have been used in measuring frequency, wavelength, resonance, capacity, inductance, resistance current, voltage, dielectric constants, and properties of materials, will be mentioned here. R300 Radio Apparatus and Equipment. A description of various types of antennas and their properties, the use of the electron tube in various types of receiving and transmitting sets, other methods of transmission of signals, various detecting devices used in reception, instruments and parts of circuits, come under this heading. R800 (539). Molecular Physics. Atoms. Popular Radio. Oct., 1926. Pp. 517-519. "Will Science Succeed in Releasing the Power of the Atom?" T. F. Wall. Evidence concerning the nature of magnetism, based on some very startling experimental phenomena, leads the writer to believe that an actual disturbance of the electronic structure has been obtained by the application of intense magnetic fields. Some of this evidence is brought out in the two curves presented, which show the relation of B to H for steel before and after having undergone an intense magnetizing process. R534. Agriculture, Applications of Farmers Radio to. and Radio. Popular Radio. Oct., 1926. Pp. 525-ff. "Sets That Earn Incomes," H. R. Kibler. It is shown how the introduction of the radio receiver into rural communities has changed the habits and methods of farmers in many ways. They now market by radio, farm by radio, are entertained by radio, and conduct their business by radio. In the charts shown, which are the results of a nation-wide survey conducted by the National Farm Radio Council, many outstanding disclosures concerning the effects of radio on farm life and community are made. R400 Radio Communication Systems. The spark, modulated wave and continuous wave systems in transmission, beat and other methods of reception, wired wireless, automatic printing, the buzzerphone and Fullerphone, will be given here. R500 Applications of Radio — To aviation, navigation, commerce, military, private and broadcasting, and the specific information under their headings, are referred to here. R600 Radio Stations. The operation, equipment, and management of radio installations, both transmitting and receiving, the testing, the rules and regulations concerning stations, the reports and bulletins issued, will follow under this heading. R700 Radio Manufacturing. Data relative to costs and contracts of radio equipment from raw material to finished product including factories, tools, equipment, management, sales and advertising, follow here. R800 Non-Radio Subjects. The matter of patents in general; the mathematics and physics, including chemistry, geology and geography; meters of various kinds; all information not strictly pertaining to radio but correlated to this subject, will be found under this heading. R900 Miscellaneous Material. R343. Electron-Tube Receiving Sets. Receiver, Popular Radio. Oct., 1926. Pp. 511-ff. LC-27. "How to Build the New LC-27 Receiver," L. M. Cockaday. A new 5-tube receiver, called the LC-27, is outlined. It is claimed to have all the ideal characteristics looked for in a modern set. These include splendid quality of reproduction, simple tuning control, selectivity, shielding, and nonregeneration. Blue prints, photographs, a list of parts, and constructional details, are presented. R113.1. Fading. Fading. Popular Radio. Oct., 1926. Pp. 531-ff. "Why Signals Fade," Charles C. Bidwell. In the writer's opinion, the under surface of the Heaviside Layer is not a smooth surface. Through the recent studies of Breit, Hurlhurt, and others in America, and of Appleton, Smith-Rose, and others in England, it has been shown that this lower surface is corrugated, or billowed, like waves on the sea, or like an irregular cloud layer in the sky. The author shows in this article how his experiments point to the same conclusions arrived at by the other scientists. Charts are presented indicating the variations of signal strength from stations kdka and w'gy at various longer periods ot time. A Key to Recent Radio Articles ■fa Examined and approved by Radio Broadcast -A"