We found this circuit in the December 1998 issue of Electronics Now magazine. RF transistors such as the BF494 or BF495 can be used. The circuit works at lower frequencies.
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...