Radio for Airplanes

Radio Record, Volume II, Issue 16, 2 November 1928, Page 5

Radio for Airplanes

FRAvIO apparatus for airplanes is rapidly becoming highly specialised, and is developing at a rapid rate. At tke present time three distinct pieces of apparatus are evolving--the receiver, the transmitter for both short and longwave, and visual indicator. Of the receivers both short and longwave instruments are being rapidly perfected. Among the most potent facters to be strived against is noise, from the engines, and that due to the passage of the ’plane through the air, as well as the electrical interference due to the magnetos. To meet these mechanical disturbances special helmets are being provided, which are soundproof, and which embody earphones. Of the tranmitters several types are appearing, many under the familiar name of Marconi. These are designed to meet the special requirements of each type of machine, long-range tele-eraph-telephone instruments for the heavier class of ’plane, and light telegraph instruments for the lighter class of *plane. The weight of these transmitters vary from about 82lb. to 1891b., the "ange being from 15 miles to very many hundreds of miles, as evidenced in the trans-Tasman and other great flights. Direction finders are becoming invreasingly popular with airmen. N air pageant staged some six months ago in England provided an excellent opportunity for demonstrating the advances made by aviation and radio. The wireless or electrical side of the pageant may roughly be divided into four classes-the land-line system, for communication between all points of the airdrome, the interplane and ground control system, the Marconiphone public address system, and the B.B.C. arrangement for .providing a running commentary to listeners. Over fifty miles of land-line were used in conjunction with forty-one loudspeakers, which latter required over one horse-power of energy for their operation, or roughly, ten thousand times that delivered to the average home instrument. as