Dual-LNB multi-receiver installation

[bibi bear]

I'm researching an installation project for my residence : a 5-story building where each of the three addresses (yes, the building has a nice long flat roof with plenty of "chiminies") contains 10 apartments - so we're talking about 30 appartements (less me and any others who choose to have their own dish SO LET'S SAY A FINAL OF 24 apartements (which by no coincidence is divisible by 4) to be hooked up.

They each want only one cable arriving to their flat which they would plug into a receiver to give them both the TPS and the Canal+/Sat bouquets (packages) - this means HotBird(13°) and Astra(19.2°).

Now I'm thinking 6 dishes wherein each would possess two what-do-u-call-them "Quattro" LNBs (which I understand to be four independent LNBs in one casing) offset in a 6° separation holder/rings.

But (and in looking at the situation one dish at a time) this gives me 8 cables which I'd like to reduce to one or two (up there on the roof) before I stick it down one of the stairway chutes whereafter I would expand it to the 8 cables again.

QUES - [looking at one (just the Astra) LNB's group of four cables at a time] If I use one of those 4-into-1 special satellite "splitters" up there on the roof and then "unsplit" and expand the 1-into-4 on the middle floor I believe that 4 apartements/receivers can independently select their own Canal+/Sat channel, n'est-ce pas? Believing this to be true (and copying this procedure for the HotBird LN- I now am confronted once again with the problem of reducing two cables (originating from different LNBs) down to one cable - Do I just use another 2-into-1 "splitter" ?

Will each DiSEqC receiver be able to independently select whatever TPS/CanalSat channel he wants?

Note: I talk about putting up separate dishes, as opposed to a truely collective dish bec 1)there may only be 12 or 16 apartements that'll have an interest and so we can just get up there tomorrow and do it ourselves 2)a collective dish probably would be more expensive and I'm quite sure that it's more complicated and it would probably require a vote who's passage would be doubtful as the residence includes another similar size building.

So please give me your feedback and please educate me as to proper terminology - THANK YOU

bibi

 

[Channel Hopper]

Sounds like its more then 'just a hobby'

You will need the eight cables from the dishes down. Where you put the boxes that do the clever stuff determines where the lower number of cables comes into play

Most decent systems install the boxes as close to the dish as possible , usually with an enclosed box or even in the lift housing.
These will only work if the cavble runs from the roof are less than say 40-50m

Once out of the box, one cable will run to each television point

Use the DiSEqC off selection for Astra 2, that allows the people with BSKYB boxes to 'see' only the Sky channels. The European boxes can be set to receive the other satellite by selecting the DiSEqC to be 'on'.

 

[bibi bear]

Thanx for reply Hopper,

Let me clarify that, as we are in France, we're only interested in the Astra 1 cluster (19.2°) and the HotBird cluster (13°) AND NOT the Astra 2/BSky cluster. - We'll be using regular run-of-the-mill Viaccess + Mediaguard decoders only(example: XSat, Nokia, Aston...)

Also my question seems to be: From one cable entering it, can a DiSEqC decoder select and filter out (at the push of a changing of a channel button) both a CanalSat and a TPS program that has gone through 5 splitters (two 4-into-1 + two 1-into-4 + a 2-into-1)?

bibi

 

[rolfw]

How much are you prepared to spend on this project Bibi? There are several ways of doing this and probably the cheapest would involve 4 of the new 8way universal LNBs and 2 dishes, each looking at 2 satellites, (the dishes would need to be big enough to ensure a good strong signal as it will have to travel a long way) and 16, 2way DiseqC units.

To comply with local and european regs you will probably need to earth every downlead after the LNB and probably tie in the dish mounts to the Lightning protection system if there is one.

This is not how I would do it personally, but is the bargain basement method.

Rolf

 

[bibi bear]

Thank u Rolf, v glad to see the resident installer get involved.
Yes, u have reservations but plz indulge me and allow me to explore the cheapest option.

If I understand your suggestion :
Installing a 1m dish w/ two 8-way LNBs - then matching up 8 pairs top-side with 8 2way "2-into-1" DiSEqC units - then draping the 8 cables down to 8 apartements ? Why would I need any more 2way DiSEqC units? And as just about no apartement would be further than 25m from the dish (except for the ground floor which would be an addt'l 8m) why would
there be any undue attenuation - isn't an 8-way LNB the exact same thing as 8 independent LNBs housed in a single casing?

Also, is that the best we can do (in terms of reducing the cable count coming in through the roof) without stepping up to more sophisticated equipment ??

BTW the lightening protection consideration seems to be v wise to avoid individual equipment failure/destruction complaints.

And as far earthing each of the downleads - I assume that can be done on the 1-side of each of the 8 2way "2-into-1" DiSEqC units ?

I was only thinking 4-way LNBs 'cause there's competition in that product's market - Heck, they're even selling those things in the megamarkets.

bibi

 

[rolfw]

[updated:LAST EDITED ON 04-Feb-02 AT 11:43 PM (GMT)]Sorry Bibi, I thought you were talking about 16 apartments, if you only want 8 then your suggestion is fine. The eight way LNBs are not normally as sensitive as the good singles and you're also going through the DiseqC unit, but if the cable runs are only 25 metres, shouldn't be a problem. Obviously if you're going to use Quads you'll need two dishes.

The earth connectors can go down stream of the DiseqC units as long as you have a relatively short run to the main earth, they're not expensive, so not that important whether you use 8 or 16.

The cable count cannot be smaller than the number of apartments served, because each apartment needs total control of one DiseqC unit and 2 LNBs. If you want to limit the number of down cables coming through the roof to 8, you will need to use external DiseqC units.

Rolf

 

[bibi bear]

Ok Rolf, Thanks to your guidance and a bit of web research, I do understand the installation much better than before. Apparently I am looking for "QUAD" (SOMETIMES referred to as Quattros) LNBs that have integrated/built-in (multi)switching capabilities (for the 4 types of signals (HighVert, HighHoriz, LowVert + LowHoriz).

PLUS I'm looking for what is referred to as "DiSEqC switches" suitable for an outdoor installation - with 2 inputs and 1 output.

>to earth every downlead after the LNB
Now turning your attention to those "earth connectors"
What are they, what do they look like, just one v much appreciated web site link can open up a flood-gate of research/information.

BTW, Ditto with regards to those 8-way LNBs (my web searcher, Copernic, didn't pick up anything) s'il vous plaït.

And lastly, what's your opinion on thoses tiny lightening in-line modules - Are they worth their price, meaning, I assume (as any interupter would) that they add attenuation and perhaps there's a simpler cheaper less intrusive way to prevent possible lightening dammage.

Bibi

 

[rolfw]

http://www.scci.co.uk/catalog/photos/24430.jpg this is the Earth strip with connectors, you need to run a reasonably substantial earth cable to the main system earth, 6mm I believe should be OK in France.

Make sure that the LNBs are Quads, must have 4 completely self contained universal outputs, not the Quatro which has HHigh, VHigh, HLow, VLow, this style is for use with a switching unit (which would be the better way to go, but much more expensive).

Don't know where to get the 8 output LNBs, they were on show at the last satellite show, perhaps they haven't proved to be too good.

Rolf

 

[Pligs76]

Just installed one of the new 8-way LNB's with built in switch from maker Digistar. Can't tell you whether it is good or not as I haven't managed to finish my installation. Cost around €125 here in Germany.

For an installation like the one you seem to be looking at check the installation diagrams at http://www.spaun.de/html/awbsp-38.html

Pligs76