I was advised to post this in this forum since I live in South Dakota. Here goes. I have a Radio Shack Pro-106 that I believe I have programmed correctly. I entered in the frequencies for the three towers that are closest to my area, which is Todd County. I then entered several objects and have been scanning, but I am not hearing anything. To my understanding, the South Dakota State Radio System runs as an APCO-25, and I believe that the Pro-106 is supposed to be able to hear transmissions on that type of a system. But mine hasn't. Any help would be appreciated.