Designed to operate with a video camera, this small transmitter was found in the February 1993 issue of Radio Electronics magazine. The microphone is electret.
This fuzz effect for guitars was found in an American 1980s documentation. The transistors may be the BC549...
This circuit is from Popular Electronics from the 90's. The circuit discharges the battery with a...
This is a circuit of the 80's ON Semiconductor thyristor manual. Of course, the configuration can be...