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 interesting circuit found in a European publication from the 1990s eliminates the voice that...
This transmitter for the 80-meter band (3.5 MHz) was found in an old documentation for radio...
Frequency divisions up to 18,384 can be performed with the basic configuration of a 4020 as shown...