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.
Suggested by an American documentation for 1969 neon lamps, this circuit provides SCR control with...
This circuit was obtained in a 1976 amateur radio manual. The circuit can be made with a 2N2222...
This circuit was taken from the 1974 Ferranti transistor manual. It is intended to use a common...