Kbtv2 beta2 uploaded

[Dieter]

In message <200802250056.18550.danny at ricin.com>, "Danny Pansters" writes:
> On Friday 22 February 2008 18:59:44 Dieter wrote:
> > > > > Your card seems to have a microtune tuner mt2050 which is not yet
> > > > > supported by the saa backend. I'm looking into it. Unfortunately it
> > > > > differs from the other generic tuner APIs for saa in that tuning and
> > > > > init are to be handled differently (mt2032 is supported by bktr, so I
> > > > > can peek there). THis is an important tuner to have support for
> > > > > though for several reasons:
> > > > >
> > > > > - it's on a chip, not in a large chunky metal enclosure
> > > >
> > > > I have read that the very small USB tuners don't perform as well as the
> > > > "large chunky metal enclosure", because some features were left out.
> > >
> > > Well, they don't have an mpeg encoder chip, but neither do the old
> > > fashioned analog TV cards. Of course, supporting that A/V decoder is
> > > another matter. But so is supporting an onboard mpeg encoder.
> > >
> > > They seem to use empia chipsets almost exclusively, the variant without
> > > onboard MPEG encoder is called the "blackbird" design IIRC.
> >
> > No, I mean the reception performance, not mpeg features.  The "big" metal
> > cans supposedly have better RF filtering.  Keeping the undesired
> > frequencies out is important.
> 
> I've been looking into how they work and what they do is they have two IF 
> stages. They demodulate to higher frequencies first (order 1200 MHZ) then do 
> the usual demod to actual IF (for PAL, ntsc, but also QAM etc).

I think you mean "frequency shift" aka "mix" rather than "demodulate"?

http://en.wikipedia.org/wiki/Modulation
http://en.wikipedia.org/wiki/Frequency_mixer
http://en.wikipedia.org/wiki/Heterodyne
http://en.wikipedia.org/wiki/Superhet