With this circuit you can produce the sound effect passing from one channel to another. The circuit is from Mullard documentation from the 1960s. The transistors may be the BC548.
This circuit is from 1950, from the time when some still called the crystal triode transistor. The circuit is...
Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982....
This high voltage switched generator circuit was found in a 70s American documentation. The...