What difference does symbol rates make?

[dashaund]

Okay, so I'm trying to understand all of this satellite jargon. Since I'm gotten into the PC DVB stuff and learning about that, I've learnt that typically the HD content has a symbol rate of 20000 or more. My question is, what is the symbol rate and what difference does it make? Can an HD signal be in the 5000s or is there something about the signal that requires that high symbol rate?

 

[Mr Tony]

symbol rate is how much bandwidth they take up. SInce you can put more than one channel on a transponder (digital), they need to split that up.

I'm going to assume that HD needs the higher symbol rate for bandwidth. I know on my Pansat when I blind scan, there are little blocks when it picks up a TP.

Higher the SR, the bigger the block on the screen
SR like 3978 or 6111 look like a pencil.

Another reaosn for higher SR is they have to stack multiple channels on a TP. Thats why Dish uses 20000 for sr and some of the IA transponders are 22000 and 23000. Becuase of the amount of channels