This simple sensitive circuit was suggested in a July 1992 Radio Electronics issue. The relay is a double-contact changeover relay. Sensitivity adjustment is made at R2.
This silencer or squelch preamp circuit was found in a documentation for radio amateurs. It...
This circuit was found in a 1994 publication. It draws 1 of 41 LEDs when we press and then release...
This circuit makes use of a diac to stop the activation of a sensitive reed relay 1 mA. The trip...