AOR ARD9800 Instruction Manua page 12

If you have changed the internal jumper for low-voltage battery operation,
battery voltage must be within the range of 5.6 ~6.5 VDC. DO NOT apply
12.0V or severe damage will result, and the warranty will be void!
Note: No low battery voltage detector is built-in the ARD9800.
r. FG
Frame ground
11