Expanded range
RX 137 – 174 MHz
TX 140 – 174 MHz
TX 420 – 470 MHz

1. Remove Battery and Antenna .
2. Remove the cover for Pressure Sensing Unit (SU-1). See Owner Manual
3. Remove the SU-1 Option board (if installed)
4. Locate solder pads on lower left side.
5. Remove solder from the fourth pad from the left (JP5)
6. Reassemble the radio
7. Reset the microprocessor. (Press and hold [ MR ] & [ VFO] & [4 ] and turn on the radio.