Radio receiver with pre-tuned channels - provides preselected station information including selectivity and stereo status and audio amplification in addition to tuning frequency

摘要

The tuner (1) frequency is controlled by a frequency synthesiser (10) consisting of a v.c.o. (11), frequency divider (12), phase comparator (14), reference oscillator (13), low pass filter (15) and d.c. amplifier (16), all connected as a phase-locked loop. The frequency divider is controlled by a signal from the channel selection control circuit (20). The signal is also fed via a decoder (18) to a digital frequency display (19). The control circuit (20) also has outputs which control the selectivity via the I.F. amplifier (2a), the stereo status via the stereo demodulator (2c) and the audio amplification Via the audio output stage (3). The control circuit includes memory facilities in which the parameters for each pre-selected channel can be stored. The memory contents are read into the control circuit each time the receiver is switched on.