Originally Posted by steve_launch
This is great info. I do have a Comcast SD box (which they gave me for my limited basic cable) but I've never hooked it up. I will try hooking it up and seeing if I even get anything on the box. If I do get my limited basic channels on that box, does that imply that there is no filter and something is wrong with my Media Center tuner?
I had to think about this one. If an HSI filter was erroneously placed on the line, here's what I would expect from a Comcast SD box:
Channels 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 18, 20, 21, 22, 23, 26, 28, 29, 72, 75, 77, 78, 79, 96, 98, 99, and 117 should work. They are transported at frequencies above which you appear to have trouble.
Channels 8, 16, 17, 19, 24, 25, 27, and 76 may or may not work. These feeds are duplicated at both frequencies at which you are having problems and at frequencies that seem to be working well for you. It depends where your box is 'looking'.
Channels 91, 92, 93, 112, 114, 115, 116, and 119 should not work. They are transported at frequencies at which you appear to be having trouble.
Channels 106, 107, 111, and 113 should not work. They are transported at frequencies above which you appear to have trouble, but an SD box is incapable of tuning these HD channels.
Channels 103, 104, 105, 109, and 110 should not work. They are transported at frequencies at which you appear to be having trouble, and an SD box is incapable of tuning these HD channels.
If what you're seeing follows this prediction pretty closely, I would hazard a guess that your line is being erroneously filtered. If your results are substantially different, something else is probably at play.