Mailing List Archive

Standard cable, QAM, PCHDTV-3000 vs Air2PC
I have standard cable (not digital, no fancy features) and would like to
get an HDTV card to set up a MythTV system. I also need NTSC, since
getting the HDTV card now is more for Broadcast Flag insurance. But our
regular cable does have 4 HDTV channels, according to a friend. So I
know it can be done, and debugged.

So, the perennial question: PCHDTV-3000 or Air2PC

The PCHDTV-3000 has built-in NTSC, which saves me a little money, but
not that much.

From what I understand, the newest rev of the Air2PC (with a new name)
has a better tuner, but I'm not sure that's important for cable.

I'm likely to stay with cable, since my stations are in multiple
directions and my wife has already registered her disdain for a rotor.

When I hear about cable, I hear about QAM. Why is a cable HTDV signal
different from over-the-air?

I've heard reports of both cards doing QAM, though the PCHDTV seems to
claim not to do it. What gives?

Incidentally, the back-end will be on an Athlon64-3000 with 160G, and
the front-end will (hopefully) be on a new-used XB0x. (How hard is it
to find a pre-1.6?)

Thanks,
Dale
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Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
On Sun, 2005-11-13 at 17:00 -0500, Dale Pontius wrote:
> So, the perennial question: PCHDTV-3000 or Air2PC
> The PCHDTV-3000 has built-in NTSC, which saves me a little money, but
> not that much.
While it is built in, currently with MythTV you can only use the card
as either a HDTV or a NTSC card, but not both.

> From what I understand, the newest rev of the Air2PC (with a new name)
> has a better tuner, but I'm not sure that's important for cable.
I don't know about the Air2PC HD-5000, but the pcHDTV HD-3000 has a
better tuner for QAM than the old Air2PC.

> I'm likely to stay with cable, since my stations are in multiple
> directions and my wife has already registered her disdain for a rotor.
Depending on your distance from the stations a omni-directional antenna
might work, and since UHF antennas are pretty small (mine is 1 ft long),
you might be able to put up an antenna for each direction.

> When I hear about cable, I hear about QAM. Why is a cable HTDV signal
> different from over-the-air?
The licenses for the 16-VSB patents are/were more expensive, and many
cable operators were already using QAM-64 and QAM-256 for non-HDTV DTV
by the time they started looking at HDTV. AOL-Time-Warner in New York
was using VSB for a while, but I believe they have switched over to QAM
now.

> I've heard reports of both cards doing QAM, though the PCHDTV seems to
> claim not to do it. What gives?
The pcHDTV HD-3000 supports QAM. The HD-2000 hardware supported it, but
my understanding is that the pcHDTV folks could not get licensed QAM
firmware for the HD-2000 from the DSP chip maker.

-- Daniel
Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
On Sunday 13 November 2005 18:30, Daniel Kristjansson wrote:
> On Sun, 2005-11-13 at 17:00 -0500, Dale Pontius wrote:
> > So, the perennial question: PCHDTV-3000 or Air2PC
> > The PCHDTV-3000 has built-in NTSC, which saves me a little money, but
> > not that much.
>
> While it is built in, currently with MythTV you can only use the card
> as either a HDTV or a NTSC card, but not both.
>
> > From what I understand, the newest rev of the Air2PC (with a new name)
> > has a better tuner, but I'm not sure that's important for cable.
>
> I don't know about the Air2PC HD-5000, but the pcHDTV HD-3000 has a
> better tuner for QAM than the old Air2PC.

the better tuner will only help with weak OTA signals, if the signal is strong
then it won't matter as its all digital, a strong signal means your getting a
low error rate copy of the stream, a better tuner won't really help beyond a
certain point.

>
> > I'm likely to stay with cable, since my stations are in multiple
> > directions and my wife has already registered her disdain for a rotor.
>
> Depending on your distance from the stations a omni-directional antenna
> might work, and since UHF antennas are pretty small (mine is 1 ft long),
> you might be able to put up an antenna for each direction.

If your cable company broadcasts all your local OTA HD stations through their
lines unencrypted, that would be the best way to go, no worries about
antennas, you always get a strong signal etc.


> > When I hear about cable, I hear about QAM. Why is a cable HTDV signal
> > different from over-the-air?
>
> The licenses for the 16-VSB patents are/were more expensive, and many
> cable operators were already using QAM-64 and QAM-256 for non-HDTV DTV
> by the time they started looking at HDTV. AOL-Time-Warner in New York
> was using VSB for a while, but I believe they have switched over to QAM
> now.
>
> > I've heard reports of both cards doing QAM, though the PCHDTV seems to
> > claim not to do it. What gives?
>
> The pcHDTV HD-3000 supports QAM. The HD-2000 hardware supported it, but
> my understanding is that the pcHDTV folks could not get licensed QAM
> firmware for the HD-2000 from the DSP chip maker.

they just haven't updated their webpage, the HD-3000 definitely does QAM out
of the box, I think they're just lazy web admins and over active computer
engineers...

Steve
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Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
Wait a minute, so let's say I have a backend machine with a PVR-250
connected to my cable service and an HD3000 hooked up to an antenna.
Presumably I would want to set everything up so Myth will use the HD3000 for
the major networks/local channels (some of which will broadcast HD content)
and the PVR-250 to capture everything else on cable. However, when recording
a major network show that's NOT broadcasting in HD - then what happens? The
HD3000 just doesn't record it since it's not HD?? Please let me know if I'm
mis-understanding how this works, thanks!!

Alex

>While it is built in, currently with MythTV you can only use the card
>as either a HDTV or a NTSC card, but not both.
Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
OTA HD stations broadcast in ATSC all the time. The content isn't always
high definition, but the HD3000 should capture it whether it is 480i or
720p.

On 11/13/05, Alex Brekken <brekkal@gmail.com> wrote:
>
> Wait a minute, so let's say I have a backend machine with a PVR-250
> connected to my cable service and an HD3000 hooked up to an antenna.
> Presumably I would want to set everything up so Myth will use the HD3000 for
> the major networks/local channels (some of which will broadcast HD content)
> and the PVR-250 to capture everything else on cable. However, when recording
> a major network show that's NOT broadcasting in HD - then what happens? The
> HD3000 just doesn't record it since it's not HD?? Please let me know if I'm
> mis-understanding how this works, thanks!!
>
> Alex
>
> >While it is built in, currently with MythTV you can only use the card
> >as either a HDTV or a NTSC card, but not both.
>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users@mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
>
>
Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
Thanks Chris, I guess I was mistaking NTSC and ATSC. Sounds like it can do
what I want then.

On 11/13/05, Chris Ribe <chrisribe@gmail.com> wrote:
>
> OTA HD stations broadcast in ATSC all the time. The content isn't always
> high definition, but the HD3000 should capture it whether it is 480i or
> 720p.
>
> On 11/13/05, Alex Brekken <brekkal@gmail.com> wrote:
>
> > Wait a minute, so let's say I have a backend machine with a PVR-250
> > connected to my cable service and an HD3000 hooked up to an antenna.
> > Presumably I would want to set everything up so Myth will use the HD3000 for
> > the major networks/local channels (some of which will broadcast HD content)
> > and the PVR-250 to capture everything else on cable. However, when recording
> > a major network show that's NOT broadcasting in HD - then what happens? The
> > HD3000 just doesn't record it since it's not HD?? Please let me know if I'm
> > mis-understanding how this works, thanks!!
> >
> > Alex
> >
> > >While it is built in, currently with MythTV you can only use the card
> > >as either a HDTV or a NTSC card, but not both.
> >
> >
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users@mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> >
> >
> >
>
> _______________________________________________
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>
>
>
Re: Standard cable, QAM, PCHDTV-3000 vs Air2PC [ In reply to ]
On Sunday 13 November 2005 20:50, Chris Ribe wrote:
> OTA HD stations broadcast in ATSC all the time. The content isn't always
> high definition, but the HD3000 should capture it whether it is 480i or
> 720p.
>
> On 11/13/05, Alex Brekken <brekkal@gmail.com> wrote:
> > Wait a minute, so let's say I have a backend machine with a PVR-250
> > connected to my cable service and an HD3000 hooked up to an antenna.
> > Presumably I would want to set everything up so Myth will use the HD3000
> > for the major networks/local channels (some of which will broadcast HD
> > content) and the PVR-250 to capture everything else on cable. However,
> > when recording a major network show that's NOT broadcasting in HD - then
> > what happens? The HD3000 just doesn't record it since it's not HD??
> > Please let me know if I'm mis-understanding how this works, thanks!!
> >
> > Alex
> >
> > >While it is built in, currently with MythTV you can only use the card
> > >as either a HDTV or a NTSC card, but not both.

the content is always HD, usually 1080i, sometimes 720p (I think FOX does
720p?). the content isn't always true HD in the sense that it is just an
upconverted 480i signal.

Steve
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