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 low power circuit for the FM band was found in a spy book from the 90s. The tunnel diode is...
This 3-decade operating range VCO was found in a 90s Popular Electronics. The circuit uses...
This circuit was found in an Electronic Design from the 90s. Operational amplifiers admit modern...