GB315830A - Improvements in and relating to radio direction finding - Google Patents

Abstract

315,830. Lorenz Akt.-Ges., C. July 19, 1928, [Convention date]. Directive signalling. - A method of direction finding comprises alternately applying to an indicating instrument after rectification the signals received by either of a pair of fixed directional aerials in conjunction with those from a non-directional aerial. In the apparatus shown, the inductances L2, L3 coupled with frameaerials are also coupled to a coil L1 connected to a non- directional aerial U, and are connected in the grid circuits of two valves arranged in a common envelope R. The plate-circuit inductances L4, L5 are arranged so that of the two coils L6, L7, fixed on a shaft rotated by a motor M, only one is coupled at a time to the corresponding plate-circuit inductance coils L6 and L7 are in series and connected to the input of a rectifying receiver E, the output of which is synchronously diverted to the two valves SP1, SP2 of the coil of a moving coil galvanometer, by means of a rotating switch S driven by the motor M, in such a wav that the currents from L6 reach one half, and from L. the other half of the moving-coil instrument. When the frame-aerials are equally affected by the incoming signals the pointer of the galvanometer remains at zero, at the centre of the scale, but deviations from a course set by the incoming signals produce deflections from the zero position. Telephone receivers T may be put in the circuit as an alternative indication.