The purpose of this circuit is to silence the hiss that exists between the stations on an FM receiver. The circuit was found in American documentation from the 1980s.
This sonic, sound or vox switch uses common SCR and transistors can be BC548 or equivalent. The...
This circuit allows you to use a calculator as a timer by directly activating a sum key with...
This circuit is from the time when photos were revealed in darkrooms. We found it in a 1968...