Radio direction finder with two channels - compares phase of summed offset voltages with phase of reference voltage

The direction finder uses two voltages dependant on the reception direction of the electromagnetic waves and as auxiliary voltage independent of the latter. The initial two voltages are phase-shifted by 90 degrees relative to one another and summed, to obtain a compound voltage, compared in phase with the auxiliary voltage to determine the reception direction. The two initial voltages are supplied via respective channels (X,Y), one incorporating a phase-shifter (1) and both coupled to a summing circuit (2), connected to one input of a phase detector (3). This receives the auxiliary voltage at its other input and provides a phase difference signal from which the azimuth angle (4) of the received waves can be directly obtd. This phase difference is also used to adjust a phase-shifter (6) receiving the auxiliary voltage its output used to compensate channel noise.