I have a radio shack pro-97 that is hooked up to a radio shack 20-176 antenna hooked up in my attic (20+ feet off the ground). The 2 are connected by RG-6. I live in Shorewood, it is near I-55 and I-80. I was initially able to pick up Chicago Main, all the DuComm's and Oak Lawn. I now can barely pick up Chicago Engelwood and DuComm South. Bolingbrook FD which is 17 miles away comes in scratchy also. Is there a way to fine tune the antenna or is there another trick to strengthen signal reception? Any help will be greatly appreciated.