Found in a 1980s telecommunications documentation, the circuit presented acts as a product detector. The modulator or mixer in the square may be that of the previous circuit.
This selective filter can be used with the previous receiver (CB19446E) in a simple remote-control system....
The purpose of this circuit is to measure the resistance of an antenna at the resonant frequency....
This circuit is from a Radio Electronics magazine from June 1969. The circuit uses two SCRS to...