This 1967 Ferranti circuit uses company components. These transistors can be replaced by modern equivalents. The sensor is an LDR.
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...