5 LNB multi-LNB setup with two LNBs for 28e?

[mgx]

Hi

Avoiding the reason why I am looking at this option, is it possible to have a multi LNB setup with 4 single LNBs (4.8E, 13E, 19E and 28E) plus 1 quattro LNB (28E). The single LNBs connected to a 4 way switch thence via. a single feed to a HD receiver. The quattro LNB connected to a multi switch thence via. multiple feeds to quadplex plates in different rooms for Sky/Freesat.

I am in central London, so would be looking at an 80cm dish, or do I need 90cm? I am roughly guessing that with size of the dish could fit 5LNB and even if the two for 28 are not perfectly aligned, the signal is strong enough to compensate.

Thanks!

M

 

[Rick]

I dont see any reason a sufficiently large dish wouldn't work with a quattro as an offset LNB, but you aren't going to be able to focus two LNB's on the same position on the same dish no matter how big it is. You would be best off using one dish for your multi lnb setup, and a seperate 60cm with the quattro to feed the multi-switch. But how many feeds do you want. If you used a octo for 28e that would give you 8 feeds, and that would be alot easier and cheaper to setup than getting involved with a multiswitch.

 

[PaulR]

Take one of the outputs for 28E from the multiswitch into your four-way switch.

Simples.

 

[mgx]

Thanks for the replies. Those are great ideas, but there are some complicating factors: 1. the multi-switch is already installed (16 way) already serving 8 quadplex plates, so I can't go with the octo idea. 2. the dish will be sited about 30m from the multi-switch, and there are already 6xWF100 cables run (don't feel like running more), so to take the output from the multi-switch to the four-way switch would mean running extra cables to site the four-way switch near the multi-switch as currently I assume the four-way switch would be sited near/on the dish. So it's a toss up between a two dish setup (safe, will work, more costly) or the original 5 LNB idea (risky). Originally I was thinking a motorised setup, but I had an installer come out today and he sold me on a multi-LNB which I hadn't thought of before. I think I might just stick with two dishes.

 

[Rick]

The original 5 LNB idea isn't risky, it just won't work. You can't have two LNB's on the same dish pointing at the same satellite. The only way to do what you want to do is to go for a two dish setup.

 

[PaulR]

There's one faint further possibility. A very few multiswitches will work off a quad LNB as well as a quattro. If yours is one of these you could have an octo pointing at 28E with four of the outputs feeding the multiswitch and the other four available for other purposes.

As Rick says, there is absolutely no chance whatsoever of co-locating two LNBs on one dish for a single satellite.

 

[Rick]

There's one faint further possibility. A very few multiswitches will work off a quad LNB as well as a quattro.

Good point Paul, I'd forgotten about those.

 

[Huevos]

Or you could put a cascade multiswitch between your quad and your multiswitch.

 

[hexah]

I am in central London, so would be looking at an 80cm dish, or do I need 90cm? I am roughly guessing that with size of the dish could fit 5LNB and even if the two for 28 are not perfectly aligned, the signal is strong enough to compensate.

A Wave Frontier T90, or Maximum T85 could be used if you wanted only one dish.

 

[mgx]

This is really useful. I think a cascade multiswitch can work, in which case with the cabling I could use twin LNBs.

One single dish with 4 LNBs. 3 twins for 4.8E, 13E, 19E and 1 quattro for 28E. There's about 5m run from the dish to ceiling space for (1) 4 quattro feeds connected to a 4 output cascade multiswitch, then 4 quattro feeds continue on next 30m via 4xWF100 to the 16 way (Vision V75-516) multiswitch; and (2) 3x2 twin feeds (4.8E, 13E, 19E) connected to 2x four-way switches, and 1x2 feeds (28E) from the cascade outputs are also connected in these switches, the 2 four-way feeds continue on next 30m via 2xWF100 to be direct connect to receiver. Advantage here is that my neighbour was wanting 2x28E feed as well, so the cascade has two spare I can use for that.

Is there a recommended 4 output cascade multiswitch? A google search found one at Conrad for a ~£80 price. Using two dishes or one dish with a cascade seems to be about break even price wise, and I would prefer one dish. There's some signal loss, but it will be on the 28E path which is a strong signal anyway.

For the dish and LNBs, I really wanted to use Inverto Black Ultras. Do you think a TD88 with Triax multi mount will work with 4 Black Ultras (3 twins, 1 quattro) for 4.8, 13, 19 and 28. - these LNB are not narrow, but with the size of the dish and the degree spacing (6 degree worst case)?

The V75-516 can put out 800ma for Black Ultra LNB, which should be more than enough for the quattro (200ma) and any requirements of the cascade multiswitch. The twin Black Ultras are 180ma. I gather it would be fine to use passive 4 way switches.

 

[mgx]

Solution attached, some tidy up and an installer visit to go ...

 

[mgx]

So the installer came to do his job. Despite being an installer for many years (which I know he has been, he runs a shop in his name that has been there for at least 10 years), he thought the configuration was unusual and strangely, he wired the twins into the 4-way switches incorrectly (i.e. both 13E feeds into one switch and both 19E feeds into the second switch) despite the diagrams I provided. That was easy for me to fix, but strange that a professional wouldn't have known that ... He tried to convince me to go with two dishes, on the point that 4.8E was probably not receivable given the spread required. I said do what you can, if not then it will just be a 3 LNB setup ... turns out the first LNB is fairly useless, it appears to get 7.0E only.

In any case, it all works as intended even despite the snow at the moment ...

Via. the quadplex outlet in the living room, I am getting Sky+ HD on both tuners. I have a further 6 quadplex outlets in bedrooms, and a single F-connector outlet in the kitchen as well, all connected to the multiswitch for Sky/Freesat/TV/FM.

Via. the F-connector outlet in the living room, I am seem to be getting the following for dual tuner (I bought a Cuberevo and seems great so far):
LNB 1 Twin ('A'): EUTELSAT at 7.0E
LNB 2 Twin ('B'): EUROBIRD at 9.0E, HOTBIRD at 13.0E, EUTELSAT at 15.8E
LNB 3 Twin ('C'): ASTRA at 19.2E
Cascade multi-switch output from LNB 4 Quattro ('D'): ASTRA at at 23.5E, ASTRA at 28.2E, EUROBIRD at 28.5E

So these new toys are going to keep me busy over the holiday break :-). Already stuffing around with PC Editor, KingOfSat, Lyngsat, etc to figure out the channels I'm interested in.

 

[davemurgtroyd]

There is absolutely no way you are getting multiple satellites from lnb 2 and I would very much doubt the same from the multiswitch. If you are scanning those satellites from the receivers menus you are finding the same frequencies being used on multiple satellite "lists" in the receivers database. The only way to confirm which satellite the lnbs are actually picking up is to look up the channels actually received (not what they may be listed as on the receivers menus) on Lyngsat or Flysat. You will almost certainly find channels duplicated across the 3 satellites you think you are receiving on lnb2.

 

[mgx]

Great, thanks for the tip. I will check that out.

Confirmed: can't see those satellites, they were showing up as duplicated.

Update: spent the afternoon playing further with this. Confirmed I can get both 7E and 9E on A, but only 13E on B, only 19.2E on C and only 28.2/28.5E on D.

Good fun for my first ever satellite setup (never had Sky nor any other before either).