I know Athens city and Loudon County both use inversion, maybe you had on one of their frequencies. I do know that a year or so ago, for about 20 minutes one day, I heard inversion on McMinn counties dispatch frequency. I am not sure what it was, Athens city on the wrong channel, McMinn CSO evaluating inversion, or what. I have listen a bit to Monroe county's dispatch, but have not heard any inversion.