Dish size for DVB-S2?

[misterpaul]

Merc II is strictly Qpsk , can't get 8psk, sad to say. Thanks to your post, though, I may try it with my skywalker-1 , it shouldn't have a problem with 8psk.


Brent

You will not be able to lock that tp with the skywalker as the skywalker only supports Turbo-coded 8psk. Sorry

I forgot to say that as long as you have a 30-33" dish you should have no problem with that tp, however once again you need a receiver that can demodulate 8psk (some call it trellis) and not turbo-coded 8psk.

 

[brentb636]

"You will not be able to lock that tp with the skywalker as the skywalker only supports Turbo-coded 8psk. Sorry"

Sorry, Me too !

Brent

 

[tifozi]

The wait for the mythical do-it-all receiver continues.

 

[Stefan]

Interesting, thanks for the info. Probably why i can never lock Tp 15 on AMC1 (12000H/28755 FEC 2/3 -> DVB-S 8PSK) on my Merc II.

If that's the NBC feeds your referring to, those are dvb-dsng 8psk (AKA trellis). Anyway, the only way to receive those is with a commercial receiver or demodulator. Also only some commercial receivers support dvb-dsng 8psk and often times it's an optional feature meaning that the original purchaser had to pay extra for it as an added feature. Bottom line is receivers that support this cost thousands of dollars. Every once in while you may find one listed on ebay and maybe get lucky for $500 - $1000 if your willing to take a chance. Your taking a chance because the receiver you buy may or may not have that optional feature enabled and often times the seller may not even know for sure.

Anyway, you are correct in that dvb-dsng 8psk is harder to lock than even dvb-s2 8psk. The type of FEC encoding used with DVB-s2 helps out here. So, you probably would need a even larger dish for that signal. I think a really good 1.2M might work in good weather conditions, but larger would be better. But unless you have a receiver capable of that type of signal there's no way you'll lock it anyway.

 

[Stefan]

I read most of this article. (not understanding alot of it).

Does anyone know what most DVB-S2 TV broadcasters plan to use or are using in terms of mode? (QPSK or 8PSK)

Page 17 talked about Backward Compatible Broadcast Mode which I thought was interesting. I wonder if Equity and others are using or plan to use this as folks upgrade their receivers.

Much information in the article went over my head but I still thought it was a good read if you are interested in how DVB-S2 works.

I think the trend is toward 8psk because generally the primary reason for going this route is to pack more into less bandwidth so as to reduce distribution cost. Satellite transponders cost big bucks. It's cheaper to have all your affiliates buy bigger dishes and new receivers than to pay the cost of more bandwidth.

One thing you have to remember is than in North America most all of the FTA signals we receive are not intended for us. It may be that in some case, the provider might not care too much that we're watching, but we're still not the reason the signals up there. Therefore making it easier for us is not high on their priority list. In fact many of them might prefer we weren't watching at all. Either way their main focus is going to be serving their needs and not ours. That's why you generally never contact a FTA programming provider about their signal. It will generally do no good as they aren't providing the signal for us and often times it may even do harm as they may not be pleased we're watching or they may not want to be bugged by us.

 

[ftarock]

That's not correct with O/V dvb-s2 in Ku I have seen so far. Not gonna go into more detail on what kind of feeds, it's a sport basketball in dvb-s2 8psk, 1m well tune has problem with it, 1.2m well tune get clean lock with errors once in a while.
Another occasion, News feed in dvb-s2, same thing, 1m lock with errors. 1.2m with marginal.
It depends on the FEC, and for the O/V, the uplink tends to ulitlize the most bandwidth as possible for the programs, leaving not much room for FEC.
That makes sense because the intended client have dishes that's larger than us here.
So far I would say 1m dish have problem with O/V DVB-S2 feeds 99% of time.
FTARock

From what I've heard and read we shouldn't have issues with the dish size when some channels on KU goes DVB-S2. Our existing dishes will be fine

 

[Mr Tony]

rock
I'm going by with what someone at a broadcasting company that uses DVB-S2 right now and will be changing their other channels soon to DVB-S2 told me.

We'll see what happens