Suggested by an American publication of 1964 this circuit is intended for the capture of signals from film tracks recorded by optical systems, common at the time.
This circuit was published in a recent magazine as a past project. It is a crystal radio from...
This is half of a 4-channel amplifier from a system published in the October 1971 issue of Radio...
The presented circuit is a sinusoidal oscillator for 1 kHz that makes use of the four amplifiers...