Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982. Varicaps of any type can be used and the components selected according to the component.
We found this interesting timer circuit or CMOS timer in a 1988 publication. The circuit is still...
This circuit can be powered by 2 or 3 small batteries. The resistor can have values between 220...
Found in a magazine 73 for radio amateurs, this circuit operates in the 144 MHz band, at a...