Shown below is the schematic for a constant amplitude PLL adapter, useful to minimize or eliminate interference in local audio equipment due to unwanted rectification of AM or SSB signals usually taking place in the input stages. The principle of operation is based on converting the SSB amplitude component to frequency/phase information only by using a PLL. Because no amplitude information remains, the signal is similar to a FM modulated signal and cannot be demodulated inadvertently in non-radio equipment. This circuit was successfully used with a Semco SSB Transceiver.

Thanks to Roel, PA0JTA for providing this interesting circuit.

Um die Bilder in Normalgröße zu betrachten, bitte Bilder einfach anklicken.

Please click on thumbnails to view pictures.

© Copyright 2002-2010 VE6AQO & DL9BBR