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.
This circuit can handle 25 A unde a 32 V voltage using a hight power old transistor. This...
This didactic circuit from a 1977 Radio Shack documentation shows how to use the 741 as a...
It can be obtained from Mouser Electronics new crystals for surface mounting from AVX with...