1. Remove Battery and Antenna.
2. Remove control knobs, screws.top panel, battery mounting track & body screws and open Radio
3. For display 220-550 MHz Pads 7,8 and 9 are open
For display 50-300 MHz Pads 8 and 9 are open and 7 is bridged
4. Reassemble radio.
Note: The exact TX and RX range is determined by the coils and other circuitry in the radio.