This panel was part of the 21 series VHF communications and VOR/ILS equipment introduced in about 1959. New design features included the use of transistors and printed circuits resulting in an overall reduction in size and weight of at least 40lb per aircraft for the whole system. With a total weight of only 57 lb, this installation was the lightest. most compact equipment of its type in production.
The system provides 560 channels with 50 kilocycle spacing. Down draught cooling is unnecessary, make this installation invaluable to modern airline operators and aircraft manufacturers.The equipment was made under licence from The Bendix Aviation Corporation U.S.A. and is totally interchangeable with the Bendix American manufactured system.
Radio Control unit in general provides VHF and/or UHF frequency selection by means of continuous selection or it may also have preset channels. The frequency and channel will be displayed by a legend through a window on the older units or by an electronic display on later units. There may be a volume control and built-in-test.
