I have a rather complicated issue related to the coaxial cables going from my OTA antenna to my TVs, and I'm having trouble pinning down where exactly the problem is. Here is my setup. I have a short run of cable going from the antenna to an amplified splitter in the attic. From there, I have a cable going to a TV with a digital converter box, a cable going to a portable digital TV, and a cable going to my new High-Definition LCD. The signal for the first two TVs I just mentioned seems to be just fine. It is the connection to the LCD TV that is the problem. We have tried several cables, including a brand-new quad shielded one, but we still cannot get a decent picture. If you hold the cable just right on the RF input, the signal will come in, but breaks up if you let go. I thought it was a problem with the RF input on the new TV. However in the same room, I still have an old analog TV, and when I connect the cable to the converter box I have similar problems. If you fiddle with the cable long enough on the RF input on the converter box you can get a pretty good picture, but occasionally you still get some pixelation and stuttering in the audio. None of these problems occur with the other two TVs. I have contemplated returning the LCD TV and getting a different one, but I'm afraid it will still have the same problem. Any suggestions on what the problem might be?
Have you tried switching the port that the cable plugs into in your attic? I assume you either have a multi-port amplifier or a splitter in the attic. Try plugging your LCD TV cable into one of the ports that your other TV's are currently using.