I am sitting here staring at the SDS200 screen watching the RSSI and D-ERROR numbers. There are 4 sites in my state (RI) and each site has between 5 and 9 (-/+) towers. I dont know much about simulcast P25 systems but we'll take one of the sites in my area as an example. The PROVIDENCE CITY site has 5 towers in various locations around the city. The output power is a bit lower than other sites because its mainly for downtown reception. I am only 6 miles from Providence. Now say out of the 5 towers, there is ONE tower in the group (or could be 2, 3?) that might be a source of simulcast distortion. I was trying to tally the list of these 5 freqs looking at scanner and when radio stops on a transmission, see what the freq is, write it down and note whether is had good/bad audio. What I am trying to say is, is it possible to DELETE from the programming in radio or software a TOWER in a site? If the 5 towers in the PROV site are all transmitting at the same time, each towers transmitting the SAME THING, why couldnt I DELETE all but the CLOSEST tower? In this particular case the closest tower to me is 4 miles away. Would this somehow CUT DOWN on simulcast distortion from the other towers in the same site further away? The variables for troubleshooting P25 simulcast distortion are WAY too many. Shouldnt I be able to recieve the transmissions from a 5 tower site, but only recieve from 1 tower? Like I said I dont understand how this works. I've been fighting this distortion since I first got my BCD996P2 back in March. I got the SDS200 thinking it would solve the simulcast issues. It didnt completely but did help on 2 of the 4 sites in my state. The other 2 sites still have occasional crappy audio. I did a lot of testing with antennas and the only one that really made a big difference, cutting way down my D error and RSSI numbers is a 6 element yagi. I can receive 2 (NORTH & SOUTH) sites pretty much with NO d-error and a low -45 to 60 RSSI. But the other 2 sites still have the occasional distortion. RI is a small state and I am right smack in the middle on a small hill. I can receive all sites in the system with both a vertical and the yagi but the yagi performs hands down the best. Filters make no difference. Coax is 50' LMR400 yagi up about 20 feet. The yagi is pointing a bit southeast. Seems to work best in this configuration. Its almost impossible to troubleshoot because there are too many factors involved. So I have been taking a step at a time. Sorry for my usual rambling but I just wanted to give details.