The TIDRADIO TD-H8 (Gen 2) has three different modes of operation for amateur radio frequencies, GMRS, or completely unlocked.   

Amateur Radio Only:

1. Ensure the radio is powered off.
2. Hold down the PTT and the STAR buttons while powering on the radio. 
3. After powering on the radio, a message will appear on the display stating data will be erased. 
4. Select MENU to confirm the setting. 
5. The radio will restart, and the radio will transmit and receive on the 2-meter and 70-centimeter bands. 

GMRS Only:

1. Ensure the radio is powered off.
2. Hold down the PTT and ZERO buttons while powering on the radio. 
3. After powering on the radio, a message will appear on the display stating data will be erased. 
4. Select MENU to confirm the setting.
5. The radio will restart, and the radio will transmit and receive on the GMRS frequencies. 

Unlock All:

1. Ensure the radio is powered off.
2. Hold down the PTT and POUND buttons while powering on the radio. 
3. After powering on the radio, a message will appear on the display stating data will be erased. 
4. Select MENU to confirm the setting.
5. The radio will restart, and the radio will transmit and receive on the 2-meter, 70-centimeter, and GMRS frequencies.