GB153690A - Improvements in or relating to wireless reception apparatus - Google Patents

Abstract

153,690. Robinson, J., Macrorie, A. K., Grenfell, G. P., and Airey, H. Morris-. Aug. 18, 1919. Wireless signalling; bearings, determining wirelessly.-The intensity of the received waves is caused to control the pitch of the note heard in the telephone. For this purpose, an oscillating thermionic valve is employed, the oscillations generated having a group-frequency which is audible in a telephone in the plate circuit, and the incoming energy is utilized to vary the grid-leak resistance of this valve, thereby varying the pitch of the note. The apparatus is particularly applicable to direction-finding systems. In the arrangement shown in Fig. 2, the oscillating valve 3 has the inductance 4 of its plate circuit coupled to the inductance 5 of the grid circuit. A condenser 6 in the grid circuit is shunted by a leak resistance constituted by the plate-filament path of a valve 8, and the value of this resistance is varied by applying the incoming energy to the grid of the valve 8. The high or low frequency receiving-circuit 13, 14 is coupled to the grid circuit of a valve rectifier 17, the plate circuit of which is connected across a high resistance 16 to the grid circuit of the valve 8. The rectifier 17 may be omitted and the circuit 13, 14 connected inductively to the grid circuit of the valve 8. A source of current may, or may not, be placed in the plate circuit of the valve 3.