GB473384A - Method of regulating radio sets and the like - Google Patents

Abstract

473,384. Valve circuits for wireless reception. KRAMOLIN, L. L. DE. Feb. 7, 1936, No. 27277. Divided out of 455,190. [Class 40 (v)] A radio receiver comprises means automatically to tune it to the frequency of an incoming signal, the control being effected by current or voltage variation, similar control means being also provided for manual tuning, manual or automatic volume control, or manual or automatic selectivity control. In one embodiment, Fig. 4, the incoming signals, the amplitude of which is kept constant by an A.V.C. circuit or limiter, pass through a condenser 15 and resistance 16. Across the latter is connected a rectifier 17 and a magnetizing winding 18 associated with an ironcored inductance 20 of the type described in Specifications 449,240 and 451,097, [Group XXXVI], and forming part of the tuning circuit. Manual tuning is accomplished by varying the resistance 62 in series with a further current-carrying winding 18<1> on the same core as the winding 18. In a further embodiment, Fig. 6, an I.F. amplifier feeds a coil 27 associated with an error detector circuit comprising circuits I, II tuned above and below the true I.F. and feeding rectifiers 28, the output currents from which flow in opposition in a magnetizing coil 29 associated with a tuning circuit 31. In a modification, Fig. 7 (not shown), the error detector feeds correcting potentials to the control electrode of a tuning condenser, the capacity of which is thus varied, such as a condenser with a piezo-electric dielectric or similar to an electrostatic loud-speaker. The auxiliary controls of tuning, volume or selectivity may be carried out as described in Specification 455,190, referred to in the Provisional Specification. Reference has been directed by the Comptroller to Specification 449,240.