GB416501A - Improvements in or relating to radio receivers - Google Patents

Abstract

416,501. Valve circuits for wireless reception. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, and LINSELL, A. A., 43, West Hill, Sydenham, both in London. March 16, 1933, No. 8008. [Class 40 (v).] The carrier frequency gain of a superheterodyne receiver is automatically controlled by varying the amplitude of the locally supplied oscillations produced by a dynatron valve. As shown, a dynatron oscillator 4 has its control grid bias varied by the fall in potential across a resistance R fed with rectified current from a rectifier 9 supplied from a tuned circuit 8, C coupled to the output circuit 7 of the high frequency amplifier 2. The locally generated oscillations from valve 4 are injected into the grid circuit of the first detector valve 3 which is preferably of the variable-mu type. The output from the rectifier 9 may be smoothed if necessary by the filter 10, 11. Manual volume control may be effected by varying the coupling between the oscillator and detector or by varying the oscillator grid bias. According to the Provisional Specification, the gain of a valve coupling the oscillator with the first detector may be varied.