This circuit was found in a 1980s documentation for amateur radio. The circuit makes use of components of the era, but modern equivalents can be used.
This circuit is from 1968 documentation. We can assemble it with more modern components such as a...
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...