Using a varactor or varicap, this 1969 Electronics World circuit has a modulation range from 75 kHz to 52 MHz. Modern equivalent components can be used.
We find this circuit in a 1980s documentation. The circuit uses uncommon components today which can...
We found this circuit in a 1977 Radio Shack documentation. The circuit should be powered, for...
With the circuit shown in the figure it is possible to digitally control the gain of an...