We found this circuit in a 1966 US documentation. It simulates a variable capacitor that can vary capacitance from 1,000 to 1. Transistors are general purpose types.
This remote-control circuit was found in Radio Electronics magazine from June 1962. It drives a...
This is the receiver for the previous circuit we found in the December 1992 Radio Electronics...
This circuit with a few watts of power was found in the April 1995 issue of Electronics Now...