How strong of a signal do I need to see a picture? I am currently getting 72 steady and it keeps bouncing to 81, Do I have to have a steady 80 to get a picture at all? I'd figure I would at least see something on the screen but I can't pick up that channel. Using the radio shack amplified HDTV antenna, I got steady 85 with the silver sensor but I had to hold it up high in a wierd position, no way of keeping it in that position permanately. I figured the rabbit ears on this radio shack antenna would do the trick, but I guess not. Any ideas would be appreciated. Thanks.