This circuit was found in the February 1981 issue of Radio Electronics magazine. The circuit uses an active component of the time and is suitable for audio signals.
Found in Motorola documentation from the 90s, this circuit makes use of a triac from that time. The...
This transistorized signal injector was one of the first that we found using the well-known...
This 200-mW amplifier uses one of the first commercial power transistors. The circuit is from a...