We have a 4 site 800 simulcast system, it reaks havoc on digital scanners. I found a simple solution. Where I live 3 of the sites are to the north and east and one to the south. What I found was a 8 element 800mhz beam cell antenna. I hooked it up and pointed it at the south tower. Wa-la the other 3 sites are nulled oouut.