Hi,

I have a Vista media center with HDHomeRun tuners which has been working great for over a year. Starting last week I no longer receive HD channels via the HDHomeRun tuner or with the tuner on my Sony HD LCD. I do not use a cable box. Does anyone know what is going to with Comcast in Belmont, MA? A few months ago they turned off a bunch of analog channels... Have they also turned off clear QAM for the major networks, or do I have some sort of problem? Calling comcast was useless... The tech didn't know what clear QAM is and insisted that I need to use a cable box.

Thanks,

Jonathan

poolej:

Hi,

I have a Vista media center with HDHomeRun tuners which has been working great for over a year. Starting last week I no longer receive HD channels via the HDHomeRun tuner or with the tuner on my Sony HD LCD. I do not use a cable box. Does anyone know what is going to with Comcast in Belmont, MA? A few months ago they turned off a bunch of analog channels... Have they also turned off clear QAM for the major networks, or do I have some sort of problem? Calling comcast was useless... The tech didn't know what clear QAM is and insisted that I need to use a cable box.

Thanks,

Jonathan

Did you try to scan the channels again?  I have Comcast in NH and I recently got a letter saying they were switching to all digital.  They might have just moved the channels around to accommodate.  If that doesn't work go to http://www.silicondust.com/hdhomerun/channels_us.  You can see what channels you should have and try to add them manually.

Note Comcast is now starting to encrypt all the extended basic channels (in my area that's everything above channel 30) making the HDHomerun a little less interesting.   Obviously, it will still work fine with broadcast HD channels.    I explain it all in gory detail here.   The latest ATI firmware upgrade for CableCARD makes using them much less obtrusive now, so I'm finally getting mine installed on Friday.

I used my Sony LCD to scan channels. If finds 4.1, 5.1, 7.1 etc. as before - these should be HD. But those channels show up blank when selected. It also finds a bunch of other channels including SD versions of the network channels.

Jonathan

mpatnode76:

Note Comcast is now starting to encrypt all the extended basic channels (in my area that's everything above channel 30) making the HDHomerun a little less interesting.   Obviously, it will still work fine with broadcast HD channels.    I explain it all in gory detail here.   The latest ATI firmware upgrade for CableCARD makes using them much less obtrusive now, so I'm finally getting mine installed on Friday.

I'm looking at the silicondust web site and am confused by the results. For my area code - 02478 - CBS shows up as channel 4.1 (what used to work in HD) and 30-1. What does 30-1 mean? I tried 30.1 but this does not work. I did find CBS at 204.1, but this is 480i not HD.

Thanks.

Jonathan

poolej:

I'm looking at the silicondust web site and am confused by the results. For my area code - 02478 - CBS shows up as channel 4.1 (what used to work in HD) and 30-1. What does 30-1 mean? I tried 30.1 but this does not work. I did find CBS at 204.1, but this is 480i not HD.

Thanks.

Jonathan

Go to add missing channels and add 30-1.  Change the type to Q256 (assuming thats what the site shows).  You can set it to be channel 4 in the guide.  Now your channel should show.

QAM channels can have two channel numbers.

At least in our area, Comcast is broadcasting all QAM channels so the first number is larger than the largest "expanded basic" channel - which has been starting around 72.  The "actual" channel number is then something like 72-1, 73-2, 103-4, ...

The cable system can assign a second number to each channel, let's call this the "virtual" channel number (there is another name, that isn't as meaningful).  Comcast assigns the "virtual" channel number to match the number used for the broadcast ATSC station.  Media Center and most TVs will detect this "virtual" channel number and use that instead of the "actual" channel number.  For example, in our are the ABC affiliate is broadcast as digital ATSC channels 13.x - so the "virtual" channel numbers for the ABC digital stations are set to 13.x by Comcast (even though the "actual" channel numbers are something above 72).

NOTE that if the cable provider changes the "actual" channel number, you will probably have to rescan the channels in order to pick up the new assignment between the "virtual" and "actual" channel numbers.

As for the 480i CBS channel you see - the cable system is likely broadcasting both the HD and SD variants of the CBS channel.  The 480i version is what is probably being used by their cable boxes to replace the analog CBS channel - for use with analog TVs.  For the local broadcast channels AND the non-broadcast channels that have HD, Comcast is providing both the HD and SD versions of those channels on their cable system.