I believe the BC350C is similar to my old 550A, as in has only 50 programmable channels that you can program your self. It is a pre-programmed scanner that has the Fire/EMS and police etc. which it scans when that particular service is selected. Each service has only so many channels to program and you should have a private with 20 channels. As for clearing a channel I have no idea for I never needed to do such but you use the search to program your channels.