This board has been developped to control the 20W Mosfet FM amplifier.

First of all, the design is in charge of switching off the 20V power supply when the SWR=2.

In addition, this board controls the RF output power level through the LM317 regulator that supplies the 2N4427 transistor.

In order to display the forward and the reverse RF levels on a lcd display, we've added two "anti-log".circuits to convert these signals into a linear response.

 

You will find on this page the photos of our prototype (pcb).
This new version will be used with the new 20W Mosfet Ampliifer.

Ros Board Schematic (PDF File)

PCB ROS Board Fichier PDF