Found in an old American documentation this FM modulator makes use of a varactor diode. The circuit can be easily implemented given the small number of components used.
This circuit is from a 1976 documentation. It makes use of isolated gate MOSFET which is already very...
This setting appears multiple times on the site from different sources. This is from a 2000 manual...
This circuit uses a current regulator from the 90's. This component is uncommon nowadays. The...