Tac-2 has been encrypted for a few years now. This channel is utilized for priority one calls, you will hear the dispatcher sound a tone, and ask all units to switch to channel 2 for a priority call. The former Chief did not want the "sensitive calls" going over the clear air and created this policy. It has stuck in place following his retirement a few months back. All patrol operations will stay on channel-1, and units not assigned to the priority calls will utilize channel-1 as well. Lowell PD has said that they plan on keeping channel 1 clear, and utilizing their encrypted channel as needed.