This circuit was found in an 80's Electronic Design. It amplifies TTL fast signals for a coaxial cable. TTL is from the S (Schottky) line and transistors are types of the time.
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...