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

Daniel Kristjansson danielk at cuymedia.net
Sun Sep 16 20:11:57 UTC 2007

On Sun, 2007-09-16 at 15:02 -0400, Matt Emmott wrote:
> 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. 

You may be wrong, the cable operator is only required to offer over
the air channels in the clear. Some offer all their regular package
channels in the clear but encrypt them in their STB, others encrypt
everything they can and decrypt them for you in the STB. And at least
one person has reported that their cable operator says they will only
allow "encryption to the screen TV sets" made by members of the 5C
cartel in the last few years (which violates at least a dozen federal

Also, there are no actual channels at "700". The cable operator squishes
up to about 8 channels into the frequency for one channel and then
remaps the numbers so 100.1 becomes 557, 100.2 becomes 530, 100.3
becomes 623, etc.

> 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.

MythTV will scan cable channel frequencies 2 to 159 and T-7 to T-14.
You can extend this, if the hardware allows, by increasing the
US_MAX_CHAN frequency in libs/libmythtv/frequencytables.cpp. MythTV
will tune any frequency the hardware allows as well.

159 is 1005 Mhz, which is the maximum for most cable systems. But if
yours went up to 2000 Mhz, you could change the US_MAX_CHAN from 159
to 324 and MythTV would scan for TV on the additional EIA-542 channels.
If a cable operator went very much past 2000 Mhz they would need more
expensive cabling and equipment so this is unlikely, they would just
switch to the cheaper fiber to the home at that point.

-- Daniel

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