We obtained this circuit in a technical documentation from the 90's. The circuit has its sensitivity adjustment in the potentiometer. The supply voltage can be reduced with a 1k resistor change.
This ultra-low noise circuit was found in the May 1990 issue of Radio Electronics magazine. The...
The sophisticated signal tracker/follower with a JFET and integrated circuit 741 was found in a...
This two-transistor limiter for low-frequency signals was found in the May 1963 Radio Electronics...