I'm using 100 feet of LMR400 with no issues. I also have a ED Fong antenna that at first I thought was junk. I could not rx anything with it and tx was almost as bad. Swapped out the radio and all was fine. I've hit both GMRS and Ham repeaters at quite a distance, The GMRS repeater is 45 miles away on a relatively high mountain top and come in very clear, the ham repeater is 52 miles away and is noisy but readable. I've had my repeater project on the back burner most of the summer. I dusted it off again last night and installed the KCT-19 cables in the two TK-880s I'm planning on using. I've also ordered a ID-O-Matic controller today. Once it shows up I'll get it programmed and hooked up.