Circuit arrangement for controlling a tuning indicator tube in combined amplitude modulation- frequency modulation broadcast receivers

摘要

726,633. Radio receiving circuits. STANDARD TELEPHONES & CABLES, Ltd. Sept. 4, 1953 [Dec. 11, 1952], No. 24549/53. Addition to 726,273. Class 40 (5). In a combined amplitude and frequencymodulation receiver in which, as in the parent Specification, the grid of a tuning indicator tube is connected on F.M. to the grid circuit of the limiter, an improved characteristic is obtained by controlling the tube in addition from the detector circuit. In a receiver comprising a limiter 1 and ratio detector 7, the grid lead 13 of the tuning indicator tube is connected to the grid circuit of the limiter via resistors R1, R3 and to the negative end of the detector circuit via resistor R2. The centre of the load resistor 9 may be earthed.