Did you program the control channels as a control channel in a trunked system or as a conventional frequency? The control channel will emit a mysterious tone because it is the main information link from the control tower to your device. If you listen to the CC directly you will only hear inaudible information being sent to radios around the county, this is not what you want to listen to. The CC is essentially the conductor of the main hub to multiple voice channels and your device will be able to decode the information. My advice would be to use some sort of programming software to setup the trunked system or read instructions on handheld programming which might be more difficult.
If you are using the Uniden software, put all the freqs in for the system you want to monitor, next to the freqs, there is a column named Trunk, this needs to be on for each of those freqs.
For the trunk settings, it should be Motorola Type2/APCO25 800MHz, Trunk Bank set to On...In my file I have for the Boone county area, I have all the freqs programmed in and I set the CC Only Mode to OFF.