Is it possible to erase a channel once programmed in a Pro-2021? I did not see a mention in the user manual of erasing or clearing a channel once programmed in the Pro-2021. I remember my old radio shack scanners allowing me to program "0" in order to clear the channel, but that does not seem to work with this Pro-2021.. There is one other weird quirk I noticed - I'm not able to lock out channels 180 or 200. When either of these channels is selected the "Lock Out" key has no effect. I don't think that is expected behavior, so I'm wondering if there is some small issue with the radio that is preventing me from erasing a channel and locking out those two channels. Otherwise all functions of the Pro-2012 are normal.