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 is from an April 1991 Radio Electronics magazine. The circuit uses power MOSFETs and...
In the figure we have a receiver for frequency modulated light signals (see the transmitter in...
This 4-transistor amplifier was found in a Japanese publication from 1957. Germanium transistors are...