This commercial transistor radio was manufactured by RCA in the 1960s. The circuit has only 4 transistors and is powered by a voltage of 9 V with an audio power of 20mW.
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...