Blount, Loudon & Roane are primarily using TACN for most traffic. Roane & Blount only use vhf/uhf for backup. Blount EMS & some of the county fire departments use uhf. Roane is strictly TACN. Loudon uses TACN for county sheriff & Lenoir City PD & FD. Loudon County EMS & all county FD, and Loudon City PD & FD use uhf. Knox Co. & Knox PD & FD use their trunk system and Knox County Fire & all EMS use uhf. Anderson (Oak Ridge) use uhf & OR trunk system, although Anderson has tested on TACN. Sevier has a complicated system using trunking systems as well as NEXEDGE & p25 digital. THP is strictly on TACN. Some of the TACN talk groups are encrypted full or part time and are marked accordingly. Hope this helps. If you have any county specific questions feel free to ask.