This old circuit from a documentation from the 70s disconnects a TV from a signal obtained on the TV itself, detecting when the tuned channel goes out of the air.
This circuit produces a pulsating intermittent sound in frequency that can be adjusted in P1. The...
We found this circuit in a Popular Electronics from the 90's. The circuit activates an oscillator...
This crystal-controlled oscillator was obtained from an American 1980s documentation. The circuit...