2 dishes for Sky+HD

L

Lindrick

Member
My Satellite Setup
1.2m satmaster (I think)
Fibre glass version.
Thompson HD digi box
My Location
Spain
Mojacor. Spain.
Is there any advantage in using 2 x 1.2m dishes instead of a dual LNB
for Sky+HD?
I have plenty of space and nobody near to worry about.
Is it possible to do it and does the signal strength increase?
 
Welcome to the forum Lindrick


Lindrick said:
Mojacor. Spain.
Is there any advantage in using 2 x 1.2m dishes instead of a dual LNB
for Sky+HD?
Click to expand...

I cannot think of any advantage, only a disadvantage, two dishes to install

Lindrick said:
I have plenty of space and nobody near to worry about.
Is it possible to do it and does the signal strength increase?
Click to expand...

No the signal strength will not increase since the two will be independant feeds to two separate tuners.

You could never successfully add two signals together anyhow, they would always be out of sync and out of phase with each other, if it were possible everyone would be doing it instaead of buying big dishes
 
Topper said:
Welcome to the forum Lindrick




I cannot think of any advantage, only a disadvantage, two dishes to install



No the signal strength will not increase since the two will be independant feeds to two separate tuners.

You could never successfully add two signals together anyhow, they would always be out of sync and out of phase with each other, if it were possible everyone would be doing it instaead of buying big dishes
Click to expand...

Thank you for the reply.
I did know that you can't sync 2 signals into one input.
The reason I asked was for the dual input that is required on the HD boxes.
I did not know that they had to be in sync as well.
So is that the case for the HD input.
So can I ask again knowing that the HD box requires 2 signals please.
If there is no advantage using two single LNB,s (noise etc) over a twin LNB then I will wait until I have built my 2.4 dish.
Thanks again.

One day I will be an expert!!! I wish.
 
I don't think they have to be in sync for the HD inputs. As far as I know each input drives a separate tuner. Otherwise there would be no point, might as well have an internal splitter for the signal which would have about the same loss as a dual-LNB splitting the signal in two (unless they sort of "balance" the signal and relies on the two cables from the LNB not receiving the same noise, but I think that is highly unlikely).

From what I've read elsewhere, the Sky HD box just has two separate tuners so you can watch one channel while recording another, etc. (similar to my MythTV setup). But having said that, the signal loss from a dual LNB compared to a single LNB is so small that it doesn't make sense to have two separate dishes. And unless you are very fringe, you might even get away with placing two single LNB's very close together on the dish.
 
As the o/p is in Spain, certain parts of which are very bad for 28.2 East, I doubt the two lnbs on one dish solution would work at all since he says he says he requires 2.4Mtr thus since the margin for alignment error reduces as the dish size increases, even two slimline Alps lnb's would still give him 3 or 4 degree separation. He needs a twin lnb or a quad.
 
Lindrick said:
If there is no advantage using two single LNB,s (noise etc) over a twin LNB then I will wait until I have built my 2.4 dish.
Click to expand...
What do you mean built? Don't say you bought one of those nasty jigsaw puzzle dishes in six sections. If so the best place for it is the dustbin. An offset dish that measures 1.2 metres horizontally will out perform it. In Mojácar a 1.2 dish with an Inverto Black Ultra LNB should be able to receive all the vertical transponders from 2D.

Lindrick said:
The reason I asked was for the dual input that is required on the HD boxes.
I did not know that they had to be in sync as well.
So is that the case for the HD input.
So can I ask again knowing that the HD box requires 2 signals please.
Click to expand...
HD tuners do not require two feeds, only one. What requires two is a Sky plus box because it has two tuners. And, no, the signals don't have to be in sync/phase. Signals only have to be in phase when multiple collectors are being used to supply a single tuner. This is something done in the world of radio telescopes, not domestic satellite TV.
 
Thank you all for your replies.
I will wait until I have made my own dish. (not a bought one with petals but a properly made one from scratch.)
If my project is successful I will share the manufacturing details with the Satellite forum.
 
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