This untuned (aperiodic) amplifier circuit was found in the August 1974 Radio Electronics magazine. The transistors are period, and the board layout is critical.
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...