Originally posted by sanjoseskater
I have had the same problems you speak of with RCN. First they came out and checked my signal levels. My levels were low. They upgraded all of my coaxil cables in the house. This helped but the problems still occured just less often. Then they came out and did some work on the Telephone pole. The problems even occured less after that, but still occured. They checked my signal levels again and they looked good so they gave me a new cable box last night. I have not experienced any signal drop outs since last night, but the motion artifacts are still present on certain programs. CBS looked great with no motion artifacts while PBS did have some motion artifacts. Mostly with PBS the problem with pixelation is when the camera angle changes. But after a few milliseconds the picture looks crisp.
I bet they have a problem delivering the higher frequencies with a super clean signal. The more motion you have the more complicated the signal becomes. Maybe the RCN plant can't deliver the signal properly over all the lines until it get to your house. But, that does not answer the question why some HD channels don't have problems and others do.
Keep being persistent with having them to come out and solve the problem. They will try to reset the box over the phone many times and cancel any appointments you have. Make sure they come out and check all your signal levels at the tap all the way to your Display. They need to fix your problems.
Signal strength from the pole to the cable box is important. But if you get crystal clean reception with some channels and not with others, the problem might be with how the cable company acquires the signal.
This goes way back, but for years the cable companies would receive local channels from over the air antennas. So if there was bad weather or local interference at the cable head-end, there would be static in the signal the cable company passed along to subscribers. It was only in recent years that local channels had hard lines delivering their signal to the cable head-ends. But not all stations have the hard lines to Time Warner and/or RCN head-ends.
Another issues with acquisition is compression and security. Another layer of possible errors is created if a station compresses or scrambles the signal it feeds cable providers. With bandwidth in such high demand, almost every channel is delivered with some sort of compression.