I currently have aa Radio Shack antenna on the second story roof, pointing at the mountain in Albuquerque ( a straight shot) where the broadcast antenna's are located. It's about 40 miles away. My OTA station signal strenght , on my 6000, run from the mid 70's to the upper 80's. I also have an amp. connected to the antenna. Most of the channels show up as red and one green on the OCA website. Any recommendations on a better antenna or is this as good as I can get it?