Satellite Feed Question For Experts

[Nytol]

Hi,
I'm a newbie here so excuse me if this question has been discussed elsewhere on this forum.I did look for it but couldn't find anything related.
I've been wondering for some time now,why can't the satellite feed be webcasted directly before it actually enters the receiver?

I know there are sat pc-cards available in the market for some time now.
What sort of bandwidth am I looking at if I wanted to webcast the raw feed (pre-receiver)?

Does the feed from the LNB to the receiver contain all the channels , in other word is it the receiver that decides what channel to show (which you are authorize to see) amongst all the channels it receives at the same time?
Or the feed only contains one channel at the time?

Thanks

 

[Ilya]

Welcome to the forum, Nytol!
Basically, the LNB passes all the signals to the receiver converting the signal from a radio wave to electric oscillations in the wires. It is the tuner within the receiver that tunes to particular frequency and decodes the signal. With one exception: there are two polarities in the radio waves coming from the satellite, but only one of them can be passed via a single wire at a time (electric signals in the wires cannot be polarized). So, the LNB switches polarity based on receiver's request. Normally you would have a dual-LNB and two wires coming from it: each carrying signals of one polarity. Other than that, all decoding happens within the receiver. (I am simplifying things a bit, but that's basically how it all works.) Hope, this answers your question.

 

[Ilya]

As for the bandwitdth, it's pretty high! You wouldn't be able to webcast it over DSL! each HD channel, for example, is around 15 Mbps!