FROM 
Prepare one 1N4002 diode for modification. The procedure IS AS follows:
- Remove the top cover
- Find corner connector J21 'Tone burst unit'
- Locate diode D10 between pins B9-J21 AND B6-J21
- Disconnect diode D10 FROM pin B9-J21, leaving the blue wire Connected
- Find the corner connector J20 'SSB IF unit'
- Locate terminal B7-J20
- Disconnect the blue AND blue-yellow wires
- Connect the cathode of the diode to terminal B7-J20 AND the anode to the disconnected END of diode D10
- Connect the two disconnected wires FROM terminal B7-J20 to junction D10 AND the new diode
- Cover the device
The output power can now be controlled WOULD the 'PWR CONTROL' potentiometer IN All modes.