|Not much can be done to these radios. Replacing the final RF transistor with a 2SC1969 is a plus. You'll have to solder a jumper across the diode going from the Audio transformer to the Driver and Final. Solder a jumper across the resister going from the base of the Final to the Driver. The output loop coils towards the back part of the radio (usually by the Final) can be spread apart, or pinched together to get maximum forward power. You should see only about 5-7 watt increase. Don't clip the modulation diode. Adjust the modulation VR pot.