By having an extended range, you are "giving permission" for the other sites/towers to access their frequencies. To start, I would recommend range setting low (1-10 miles) This will take out the statewide sites out of your immediate area. Simulcast systems are unique. I will try to find a response sent to me and email it to you. I can hear departments 30 miles away on the same system with a stock antenna crystal clear. You'll have to monitor what sites they're talking on then through Sentinel (if that's what you are using), set avoids for the non active sites that keep appearing. It sounds difficult at first but not too bad to resolve. If departments are on the same system, keep them on the same favorites list by issuing number tags so you (the scanner) don't have to keep accessing the same system and virtual start scanning all over again. This will speed up your scan speed. For distant departments, you may have to increase range.