Tunnel diode simple noise generator (CB23705E)

This circuit was found in Radio Electronics magazine from November 1960. The circuit is powered by a photocell of the time.

Crystal Calibrator (CB21783E)
This circuit generates a 1 MHz signal for general equipment calibration. The circuit is from an...
Infrared Audio Link Receiver (CB16695E)
This circuit was found in a 1992 documentation. It uses a photo diode as a receiver and an...
Line Amplifier (CB19052E)
This amplifier for audio transmission lines was found in a 1961 American publication. The critical...