[mythtv-users] Standard cable, QAM, PCHDTV-3000 vs Air2PC

[Dale Pontius]

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