Radio age (Jan-Dec 1926)

RADIO AGE for February, 1926 The Magazine of the Hout 57 discovered experimentally in tests between Schenectady and Long Island can thus easily be explained. This conception of the wave motion is also a help in explaining the phenomena of fading. There is already much experimental evidence that fading is a phenomenon of interference. In other words, the fading is due to the fact the radio waves arrive at a certain point through two paths. The waves will sometimes add to each other and sometimes neutralize each other. If we keep in mind the observations on the mechanical model that the waves in the two planes can be traced through separately and distinctly, we may conclude the two paths of the radio wave which produce fading are not necessarily two separate physical paths but may be the two paths in the horizontal and the vertical plane of polarization. For further illustration of this we can, in the mechanical model, introduce a detector. If we place this detector at a certain distance from the origin we find the detector gives no response when the system is adjusted for different velocities of propagation, whereas, it gives a maximum response when the system is adjusted for equal velocity in the horizontal and vertical plane. The phenomena of fading has thus been reproduced mechanically through polarization in a single wave path. It is not hereby suggested this mechanical equivalent is sufficient to explain the fading in actual radio transmission. It is, however, offered for what it may be worth as a help to interpret the many observations in actual radio transmission which are being accumulated. Storage Batteries Enter Lives of Millions ( Continued from page 16) TVTOW that we have discussed the ~ battery — its active materials, its electrolyte, the formation of lead sulphate and other chemical matters, you will perhaps ask how it stores electricity, and the answer may surprise you that the battery does not store electricity. The electrical energy which the battery receives when it is charged is converted into chemical energy. The chemical energy is stored by the battery, and when we discharge the battery this chemical energy is again transformed into electrical energy. Scientific research has taught us the storage battery obeys the fundamental laws of electrochemistry and thermodynamics. If this conversion of one form of energy into another seems strange it is nevertheless a part of nature's process. Batteries have been improved notably within recent years. Tests in accordance with well defined specifications show this to be true. Standard methods of rating batteries are being established. Batteries of comparatively light weight for aviation are being developed. Research is playing an important part in this advance. A Compact Straight-LineFrequency Condenser <r HE new S. L. F. Bradleydenser is the outcome of long, careful research in condenser design. It provides straight-line-frequency tuning over the entire circumference of a 360-degree dial. Stations are widely and evenly spaced over twice the dial-spacing of ordinary condensers. This unique control is obtained by using a special cam on the condenser shaft which provides the straight-line-frequency tuning now demanded by all set builders. The efficiency of the condenser is extremely high, due to the unique construction that practically eliminates insulating material in the condenser. 71 NOTHER outstanding feature of the new S. L. F. uXL Bradleydenser is the compact design which eliminates entirely the long eccentric rotor plates, ordinarily used with straight-line-frequency condensers. The Bradleydenser can be substituted for any condenser on a set without interfering with other parts on the panel. The one-hole mounting also simplifies installation. The S. L. F. Bradleydenser is the latest Allen-Bradley contribution to better radio. Be sure to bring your set up-to-date by getting a set of S. L. F. Bradleydensers from your nearest dealer. Other Allen-Bradley Devices Use the Bradleystat, Bradleyleak, Bradley, ometer, and Bradleyohm in your next set. For re amplification, use the Bradleyunit Resistor, Mail the Coupon | Allen-Bradley Company, 289 Greenfield Ave., Milwaukee, Wisconsin. Please send us your latest literature on the new S. L. F. Bradleydenser and other items of the Allen-Bradley line. Name . . . Address Tell them you read it in Radio Age