[mythtv-users] All my unencrypted HD channels are in the 700s. Can Myth tune that high?

Eric Robinson ryunokokoro at gmail.com
Sun Sep 16 19:48:46 UTC 2007


> I have Charter cable tv. I just picked up a QAM capable TV, but it
> doesn't tune past channel 114.5. All my HD channels like ESPNHD,
> ABCHD, etc, are up around channel 700. I am assuming that these are
> unencrypted since they are non premium channels - Please correct me if
> I'm wrong.
>
> Anyways, since my TV doesn't tune that high, I was wondering if I
> could get to these channels via Myth and an HD card, like the pcHDTV
> HD-5500. My tv has a VGA input so I was thinking (hoping) that the
> signal from HD to MythTV to TV would be high quality enough. Is there
> a limit to how high Myth will tune an HD card, or is it a limit of the
> card? Is anybody using Unencrypted HD on Charter? I'm in Massachusetts
> and my TV is a Vivitek 46D1. Thanks.

The person I'm building a MythTV network for, my father, lives in
southern New Hampshire and also has Charter Cable.  I did a little
research and found that you will likely need to upgrade your
rented-from-Charter set-top-box to something that uses Firewire (at
least that's my understanding of the matter).  The following web page
shows connections to the DCT6200, a Firewir-capable set-top-box that you
can rent from Charter:

http://www.charter.com/Visitors/Support.aspx?SupportArticleID=1156

A quick search of the MythTV wiki shows that people have been connecting
that set-top-box to MythTV networks for over a year now.

My father is currently renting the Scientific Atlanta Explorer 3000,
which is Firewire-less.  We're going to be requesting a switch to the
DCT6200 once the backends get built.

*SPECULATION - or, Educated Guessing*
That being said, maybe I'm missing something.  Take a look at this:

http://www.silicondust.com/wiki/hdhomerun/channels

When I add our zip code I get a big table.  The second table shows
Digital Cable QAM-256 channel information.  I have to admit that I don't
quite understand the columns.  The channels have two columns to define
one of them: Channel and Program.  That makes me wonder if there isn't a
lot of stuff happening behind the scenes where, say, "Cartoon Network"
is actually a "program" within a wider "channel" (such that each channel
has multiple programs that set-top-boxes and TVs map to
human-understandable Channels).  I'm making a guess here, but that
appears to be the case.

That being said, what QAM does your television support?  Is it QAM-256?
 The higher that number (I believe the max is 256 at this point), the
more data can be physically pushed through a cable.  Perhaps your TV
can't read that high?
*END SPECULATION - okay, no more guessing*

One last thing to check:
http://forums.bham-lug.org/viewtopic.php?t=1233&sid=360746fe40a6b3f513d28fd397c2f0c1

In that forum, people appear to be talking about something very similar.
 The first reply makes it seem like you should be able to read those HD
channels (in the 700s?) with a tuner card.  I will be testing once our
system is built.  Anyone else have any insight?

- Eric


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