[chirp_users] CHIRP VHF / UHF band "low / high" band limits ?

[Constable John Vith]

We are a state law enforcement office using CHIRP to program "QYT - KT
8900 D" units for use in our prisoner transport and patrol vehicles. Our
area (Greater Pittsburgh, PA) is one of the few areas nationwide where due
to congestion the   "T-Band" UHF (480 - 520 Mhz) is in use. Under the
"Settings - Other Setting" tabs on CHIRP the band limits are "grayed out",
preset to 136 - 174 Mhz VHF  and 400 - 480 Mhz UHF. How can we change the
"high" (upper) band limit for UHF from 480 Mhz to 520 Mhz ?