This circuit uses a parallel resonant crystal to control the frequency. The circuit is from Radio Electronics magazine, February 1993. Equivalent transistors can be used.
We found this circuit in a 1994 documentation. The circuit enables timing at dusk by keeping the...
This FM advertising suppressor (SCA) decoder circuit was suggested by Signetics in a 1980s...
This circuit is based on documentation from the operational's own manufacturer, from the 80's. The same...