I am setting up a number of BF UV-5 for a mixed batch of ham-licensed and non-licensed users.  Using MURS and GMRS for most of the of the users, but i need to lock out everything else (eg. US weather service). at the same time, we will have a couple of ham repeaters for several of us licensed operators.  How can I selectively disable transmit function in CHIRP?  Can't find anything in the miniature hard-to-read BF manual.