I live in zip 33180 and I am only about 4 miles from the tower. I have an RS VU-75 mounted on my roof. Its wired w/ rg-6 to a dipex then 50' of rg-6 to the other end of dipex and to the tv. All of my channels that I should get come in fine, 85-98% and stay fine. CBS for some reason will lock on...