Automatic digital control device for exact frequency tuning of a receiver

摘要

In a voltage synthesizer type receiver in which the tuning frequency is varied in first and second directions and in which a tuning frequency is automatically obtained in response to detuning detection signals produced from a window comparator, a hysteresis characteristic of the window comparator is compensated for by using a second up/down counter to control the tuning frequency variation in the second direction so that it terminates half way between the trailing edge of a first detection signal and the leading edge of a second detection signal so that exact tuning is accomplished.