Problem solved! For some reason it didn't even occur to me to use the antenna signal meter like the dish signal meter. Of course I didn't discover that until later since the installer tuned in the dish. With that knowledge, I kept moving the antenna around in the attic while why my wife was giving me the numbers. I got it stable so it's in the high 70's to high 80's all the time. Now the channel I was having problems with doesn't have pixelation anymore. I noticed before I did this that the signal meter when watching that channel would drop to 5 every so often so that was the obvious problem with the pixelation. FYI the antenna did end up tilting about 20 degrees like was suggested. Thanks to everyone here for their suggestions!!!