All A/V equipment in our house is centrally located. We use both Directv (must have for NFL Sunday Ticket)and Comcast basic cable. Even though we get local channels through Directv, having Comcast as a backup is a must for my wife because she's somewhat of a freak watching local channels during storms when we could lose the satellite signal. We have a total of 12 video feeds that we currently modulate on channels 83-92 and 103-124 along with a low pass filter that cleans up channels 80 and above. We finally bought an HDTV and would like to get Comcast digital to take advantage of local HDTV. I've tried a couple of antennas but we are surrounded by tall trees and I can't get good signals. My issue with Comcast digital is how do I now modulate my signals. If I continue to clean up Channel 80 and above I can't get all of the signals now available on Comcast digital. Any suggestions would be appreciated.

To make this work you have to split the incoming cable and take one lead directly to the HD cable box, and the other lead will go to your cable system the way it is now. Digital cable boxes make modulation very tricky and this is the only way to get around it. Just make sure your cable strength is strong enough.

Question regarding the lead going to my cable system the way it is now. Since this will be digital cable do I need to do anything different. Will my non-digital TVs still be able to get cable channels below 80 (channels not cleaned up) and will I still be able to modulate those above 80 like I do now.

Diesel, actually I had another thought based on your reply. I should be able to take the output from the cable box, modulate it, and feed it back into the modulated cable system for the non-HD TVs in my house (except for the HD channels). Does that make sense.

You can do that, just make sure you have enough cables to make it happen. As long as you have a low pass filter in place, you will still be able to get your regular cable channels 1-80 on all your regular tvs.

You can always run a second line to each tv with a cable box and use the TV's tuner for modulating the Sat. Send the HD line before the low pass filter.

Thanks for the answers.