I kept an ear out Friday AM for interesting comms on CharMeck and Viper Systems (Huntersville Site). Logged nothing on VIPER. EVENTS 2,17,18,20 on CharMeck system active. Events 17 seemed to be main channel. Heard unknown unit doing radio checks for hand helds used by NCHP. I assumed at that point that the important activity was happening on Events 17 for CPD and NCHP.