Thanks for your time and information! I have barely gotten past the basic setting channels and repeaters that don't require possibly half of the settings listed in my radios. Just found out about the tot use, reason and setting. My GM-30 has an offset setting, that is disabled. The manufacturer hasn't been able to provide any documentation on the function page and the channels have been hit and miss. Figured out what DIY channels mean.... 500 channels,,,,, sure!