This circuit was found in a Philips documentation from 1970. The components are of the time, difficult to find today, but the configuration can be adapted to use modern equivalent components.
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...