This somewhat complex circuit was found in the May 1984 issue of Radio Electronics magazine. The circuit drives a power stage with a triac for loads connected to the power grid.
This simple transistor tester circuit was found in the February 1968 issue of Radio Electronics magazine....
This powerful inverter provides a high-quality sine wave signal. I found it in a Radio Electronics issue...
This squelch is activated by its own noise, acting automatically. It is used in communications...