This circuit was found in General Electric documentation from 1968. The circuit uses triac from the time as well as transistors that can be replaced by modern equivalents.
This interesting sensor for RF signals was found in an article in the June 1989 Radio Electronics...
The frequency of this oscillator depends on the inductor and capacitors in parallel with it. In...
This circuit was found in RCA and General Electric documentation from the 1980s. The circuit has...