Automatic tuning synchroniser for selective receiver - has frequency multiplier between filter stage and frequency meter which is a numerical counter

摘要

The system is designed for the automatic tuning synchronisation of a selective receiver measuring the frequency change of an external alternating frequency. The system has a frequency multiplier which multiplys by a factor 10m (m being integral number). The frequency multiplier is inserted between the output of a filter stage and the input of a frequency meter. The frequency meter is a digital counter fitted with counting duration control device. The system has a local oscillator which is a frequency synthesizer. The frequency control signal is processed by digital and logic circuits to deduce the numerical indication of the frequency meter.