Tone Oscillator (CB22066E)

Found in old documentation, this oscillator with the LM380 produces an audio tone in a speaker. Frequency is set in VR1.

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...