Found in English documentation from the 1990s, this circuit can employ equivalent components. The capacitor must be low leak type. The circuit can operate as a shield.
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...