[linux-dvb] Re: DVB-S with CI card to buy

[Ragnar Sundblad <ragge@nada.kth.se>]

--On den 11 juni 2004 22:01 +0200 Kenneth Aafløy <ke-aa@frisurf.no> wrote:

> So was the crappy power-supply the root of all your troubles, or have you
> had  other problems as well? I guess the cards ain't some kind of magic
> device  which can filter away noise from a crappy psu, hmm? Keep in mind
> that it's  receiving fairly high frequencies, and noise is not it's best
> friend.
There is absolutely nothing magic about filtering power supply
lines for analog sections of computerized devices.
Actually, it is what such devices have to do, but doing it
right is not that easy.

That is not the only problem with those cards;
My DVB-T FF card has an impedance mismatch between the tuner
and the demodulator that most probably explains why its
reception is so much worse than my set top box.
The same card has waves traviling over the screen on the
composite out. Probably a power distribution/filtering
problem. It seems that most or all DVB-T FF cards has that.
My DVB-T budget's tuner broke after about 6 months (how often
do tuners break (if not struck with lightening)?).

It seems that there are much less problems with the DVB-S
than the DVB-C and especially the DVB-T cards, I guess because
there are intergrated tuners and demodulators for DVB-S which
handles most or all of the analog considerations in a tin box.

/ragge