This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
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...