Re: 1U server with 4 SATA ports and a 32-bit PCI slot
On Wed, Mar 22, 2006 at 02:03:46PM +0100, Soenke von Stamm wrote:
> Am Dienstag, 21. M?rz 2006 22:21 schrieb Hamish Moffatt:
> [...]
> > ATSC (the US digital standard for over-the-air terrestrial) is only used
> > in North America and Japan. The US is using DVB-C and DVB-S though
> > (cable and satellite).
>
> Very interesting, thanks alot!
>
> I was always wondering why DVD-C and DVD-S need different hardware though they
> operate on the same media basically. Analogue TV can be received with the
> same receiver, be it terrestrial or cable-based. For digital you'll need two
> different cards though. Are the frequencies used the big difference or is
> ther more?
Well at least in north america, the signals sent over the air match with
cable signals for channels 2 to 13. Past that the frequency spacing
changes and the channels on cable and off the air have different
frequencies. On digital cable, it is entirely different of course. So
yes analog signals have some sharing between cable and off the air, but
not much. The encoding is of course the same for both.
I believe DVB probably uses very different frequencies on cable and
satelite. Satelite after all uses frequencies that can go long
distances through the atmosphere, while cable wants a frequency that
works well through their cable network. They may share the encoding
system, but if the frequencies are very different, you will need
different hardware to receive them.
Len Sorensen
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