We found this circuit in an Australian publication from 1991. It is a kit of the time with input for a guitar pickup. The range is a few tens of meters.
This interesting circuit for analog TV selects the first line of a frame. The circuit was found in a...
This circuit was found in a 1967 EEE. The components are from that time, but the circuit can be...
Found in a 1968 documentation, this circuit provides symmetrical voltages determined by component...