This circuit was found in a 73 magazine for radio amateurs from the 90s. The circuit uses high voltage transistors and the relay is high voltage as well.
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...