This circuit was found in an American 1980s documentation. The transistorized step is the receiver's last IF and the diode is the receiver's existing detector.
The signal from this circuit found in a 1968 Electronics World is sinusoidal and depends on the...
This circuit is from a 70s Burr Brown documentation. The components are from the time and the...
The circuit shown is from the 1994 National Semiconductor Linear Applications Handbook. The...