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.
This circuit makes use of unusual components today. We found it in General Electric documentation from...
The ADC801 is not an easy component to obtain today, but the configuration is worth reference. The circuit...
The operational amplifier used in this circuit is no longer common on the market, as the circuit is...