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 in the low 90s but for some reason will flicker, sometimes every 30 seconds other times every 5 or 6 min. This does not happen with any other channel. Ive tried tweaking the antenna by moving it a bit but it doesn't seem to help. Any suggestions. Would any sort of amp help?