Varactor diodes are our varicaps of today. This circuit for switching signals in an RF circuit was found in a Radio Electronics magazine from July 1982.
The current drained by this circuit, from a 1976 documentation, is 3 mA and the cut-off frequency is...
We found this receiver circuit for modulated light in a 90s Popular Electronics. Equivalent audio...
This circuit turns on and off when a short pulse is applied by SW to the input of the first...