This squelch circuit is placed at the input of the single receiver audio amplifier stage. Its purpose is to silence background noise. The circuit is from an 80's documentation.
We found this circuit in the magazine Eletcronics Now of July 1994. The power supply is according to...
This simple circuit produces a tone when triggered by any vibration picked up by the sensor. The...
In the figure we show how two diodes can be used to simulate the center tap of a push-pull driver step....