While I was in AC for FDIC East, I tried to monitor the AC TRS using the control channels in the RRDB (857.7625 & 858.7625), however I missed a bunch of traffic. I then added 859.7625 & 860.7625, and it worked fine. Does the system always use 4 control channels instead of 2 as listed? ![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)