This 80's circuit uses an audio amplifier to obtain a symmetrical source from a single source. The maximum current is on the order of 1.3 A and the input voltage must not exceed 20 V.
This circuit was found in a 1980s documentation. Modern general purpose transistors can be used....
This circuit is from an old American amateur radio manual. The circuit shows how to use a Varicap...
We found this circuit in a Popular Electronics of the 90s. The circuit can also be used as a seat...