A Course Indicator of Pointer Type for the Visual Radio Range Beacon System

A form of tuned-reed radio range beacon course indicator is described, called a reed converter, in which the course indications are not given by observing the two reed motions as heretofore, but by means of a zero-center pointer type indicating instrument. The motion of the two reeds generates small alternating voltages, which when rectified by oxide rectifiers and passed in opposing polarities through a zero-center indicating instrument, serve to give course indications by the deflection of the indicating instrument needle in the direction of deviation of the airplane from the course. Each reed converter unit consists of a polarized reed tuned to one of the beacon modulation frequencies. The reed vibrates between a set of driving coils which are supplied with the signal from the radio range, and also extends between a set of pickup coils, and generates a voltage in these coils. Since a null method of course indication is used, it is necessary to provide a signal volume indicator in the form of a 0-500 microammeter in the output circuit of the oxide rectifiers. Several forms of converter selector switch circuit arrangements are shown. The advantages and disadvantages of the reed converter as compared to the tuned reed indicator are discussed.