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 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
