The TIDRADIO TD-H3 (HAM version) 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, you will see a menu with three options for HAM, GMRS, and Normal.
4. Press #1 to put the radio in HAM only mode, and then press YES 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 the STAR buttons while powering on the radio. 
3. After powering on the radio, you will see a menu with three options for HAM, GMRS, and Normal.
4. Press #2 to put the radio in HAM only mode, and then press YES 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 the STAR buttons while powering on the radio. 
3. After powering on the radio, you will see a menu with three options for HAM, GMRS, and Normal.
4. Press #3 to put the radio in HAM only mode, and then press YES 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.