Metal Detector (CB21929E)

This two-transistor metal finder was found in a Raytheon manual from the 1950s. The transistors are germanium from the time.

High Side Drivers PWM controller (CB15567E)
The circuit shown in figure 8 is an application suggestion for ISL8107, a new integrated circuit from...
Audio Oscillator (CB21907E)
This blocking oscillator that appears elsewhere on this site from other sources, was found in a...
Four Transistors Reflex Receiver (CB18301E)
This is a diagram of a 1958 commercial receiver. The circuit was found in documentation at the...