Variable regulator with crowbar protection (CB21189E)

This circuit was found in a Popular Electronics from the 90's. The power transistors must be equipped with a heat sink.

Sensitive Logic Detector (CB24487E)
This configuration (using a logic gate with TTL compatible output) uses an amplifier transistor to obtain...
Beat Oscillator (CB4208E)
Placed near a common receiver, this oscillator is intended to generate a beating signal to receive...
MM5316 Clock (CB24259EE)
Published in the September 1973 issue of Radio Electronics magazine, this diagram may be useful to...