Sat System Architecture Q

spongebob

Hi

I am trying to design a system where

1. There is 1 dish (Wesht of Ireland) of 80-90CM
2. There are 2 x LNB's , one for Astra 2 and one for Hotbird
3. There will be 2 receivers

What I am schtuck on is the Diseq stuff. If Receiver A is watching Hotbird and receiver B sends a signal that it wishes to watch Astra, how can I ensure that Either LNB may be selected by Either receiver at any time, they will have separate cable runs from the attic down...it strikes me that a simple toggle instruction would cause endless grief.

Yours headscratchingly and in hope.

M

watty

There are two ways to do this

(1) Cheap Simple way, no switch. Each RX gets only one LNB, but both LNBs are on one dish. Each LNB is ordinary single o/p LNB.

LNB1
13E ]

---

[Receiver 1]

19E ]

---

[Receiver 2]
LNB2

OR

(2) Expensive way:
Uses TWo dual o/p LNBs and two Diseqc switches

13E ]---------( )---------[Receiver 1]
     --     --( )Diseqc 1
       \__ / _______
     _____/         \___( )
19E ]-------------------( )---------[Receiver 2]
			Diseqc 2		

I'd go for method 1!

spongebob

Option 2 it is i I fear,

Can it be scaled up to 3 receivers (3 Diseqcs required I suspect)

What spec diseqc is required for 2 or 3 receivers off 2 LNB's

---

13E ]

---

( )

---

[Receiver 1]
-- --( )Diseqc 1
\__ / _______
_____/ \___( )
19E ]

---

( )

---

[Receiver 2]
Diseqc 2



BTW What does o/p mean

Thanks for the Help

M

watty

Erm, yes, but why?

1 Diseqc switch box per receiver.

LNB not shared = 1 o/p (output) connector
Shared to two receivers = Dual LNB, two o/p connectors
Shared LNB for 3 or 4 Receivers, QUAD LNB = 4 o/p connectors.
(Triples are like hens teeth).



A "Global" brand DiseqC switch can be used with 2, 3 or 4 Inputs (Mounts at dish, about size of ciggy box / pencil case)
1 O/P = output, which can't be shared. Diseqc switch o/p can only feed one receiver.


For 3 Receivers you would need Quad o/p (output) LNBs. Each receiver needs a separate LNB connection.

The "Global" Diseq switch allows a Diseq 1.0 or later satellite receiver (Just about everything EXCEPT a digibox, including many european Analog Receivers -not the old Sky Analog boxes!)

It about 70Stg + PP +VAT for a Quad LNB.
It about 20Stg + PP + VAT for a 4 way Diseqc Switch

Both Tony and MArtin Pickering are good:
www.satellite.ie
www.satcure.co.uk


Once you go more than 4 receivers a different type of LNB is used a Communal system.

Does every receiver *REALLY* need to to see every satellite?

I have dedicated satellites per receiver:
Analog 13E
Analog 19E
Digibox X 2, both 28.2E

And for multisatellite
28.2E, 19E, 13E on one dish
Stearable 2nd Dish
All four into a 4 Way Diseqc switch, single coax back to PC satellite card.

Or are you wiring up 3 bedsits?

spongebob

Originally posted by watty

Once you go more than 4 receivers a different type of LNB is used a Communal system.

Does every receiver *REALLY* need to to see every satellite?

I have dedicated satellites per receiver:
Analog 13E
Analog 19E
Digibox X 2, both 28.2E

And for multisatellite
28.2E, 19E, 13E on one dish
Stearable 2nd Dish
All four into a 4 Way Diseqc switch, single coax back to PC satellite card.

Or are you wiring up 3 bedsits?

Thanks Watty. Close on the bedsits theory but they are flats
<cough> .....albeit rented.

A mate in Galway has a North facing flat. The bloke across the hall is South Facing and can mount the dish and likes the cheap Beebs idea. NTL have not cabled this block I think, some row with the landlord who is a moron anyway. The landlord told the south facing fella he could install a 'Minidish'as long as he left it there if he left the flat. It'll be a big minidish by the time its in but the landlord never shows up if the rent is paid on time.

The lad above the north facing flat is muttering interest as well.

Thanks a lot for the really clear system design, I will sketch it out for them.

M

Tony

Are the 3 bedsits using the same electrical fuseboard?

Tony

Originally posted by Muck
Thanks Watty. Close on the bedsits theory but they are flats
<cough> .....albeit rented.

A mate in Galway has a North facing flat. The bloke across the hall is South Facing and can mount the dish and likes the cheap Beebs idea. NTL have not cabled this block I think, some row with the landlord who is a moron anyway. The landlord told the south facing fella he could install a 'Minidish'as long as he left it there if he left the flat. It'll be a big minidish by the time its in but the landlord never shows up if the rent is paid on time.

The lad above the north facing flat is muttering interest as well.

Thanks a lot for the really clear system design, I will sketch it out for them.

M

spongebob

each has its own meter at ground level and a fuseboard inside upstairs.

byte

Originally posted by Tony
Are the 3 bedsits using the same electrical fuseboard?

Tony

Sorry, Tony, but I'm curious as to why you asked that question!?

watty

Could be problem if on different phases. You'd need some heavy earth wires to link the SCART/LNB socket earth of all the receivers together.

Not everyone needs to have all the LNBs. Anyone that wants only on sat, just connect their box to its own LNB socket leaving out the Disqec switch.

Note a Digibox can't (on its own) do Diseqc switch, nor is much use on other than Sky's 28.2

If only one person wants all the LNBs and ther others just want Sky, then only one Qaud is needed.


Dunno what Tony has in mind though..

P.S.
To do "text" diagrams use the (code) and (/code) tags around the text using [ square brackets.
"Draw" it in Notepad using Courier or Lucidia Console, select text and copy/paste with Ctrl C from notepad, Ctrl V to relpy window inside "code" tags.

Tony

Originally posted by irishbyte
Sorry, Tony, but I'm curious as to why you asked that question!?

Well there are safety implications connecting devices on different fuseboards, notmally these would be connected using a switch and earthing bar to give all the coax's a common earth.

Tony

spongebob

I suspect that a block of 9(ish) flats would be on a single phase anyway.

If it was a block of 50 flats then there would be a 3 phase power supply and the phasing could (would more like) be an issue as Tony said.

The 'power' for the whole setup should come from the south facing flat, if the Global Disecq is primarily powered from the first inputm that input will be in the south facing flat.

The 2 north facing flats would have their own receivers, thats all.

I assume that the current around the dish is DC anyway (LNB's and DISECQs and CO-AX back to F type connector on a given Receiver. Each receiver could send a Diseqc command using DC.

I can check that the AC feeds are all on one phase though !

Demographics for Watty!

There are Italians in 2 of the three flats. There are Paddies in 3 of the 3. Hotbird will be required in 2 out of 3, Astra in 3 out of 3.

The Italians are all living in the North facing flats.

If there were no Hotbird requirement then it would be simple. Fortunately (for me) the Beebs won't go free till the 14/07 so I have a few more weeks to get me head straight. In the meantime they have run Cat V around the 3 flats and will share a DSL line. Its very cozy down there.

M

watty

Each DiseqC box is powered by its own receiver.

Each LNB is fed power by the sole receiver using it if only one receiver selects it via Diseqc. I'd guess the recievrs share the powering or higest voltage receiver "wins" in powering the QUAD LNB if several Diseqc switch boxes select the same LNB.

The "earths" are all commoned by the coax outer, which is why all the receivers need to be on same phase, or otherwise you need a single strong earth wire connecing to each receiver, at some pont on the rear of case connected to F-Connector outer.


Basic points:
Each LNB connector can only feed one connector.

Each Diseq Switch input can only go to one LNB, but not all need connected. A Diseq Switch "common" out connects direct to only one Receiver F-Connector input.

A Receiver F-Connector input can connect to a Diseqc switch output OR an LNB output.

You can loop all the RFs on the boxes on separate channels and watch what someone else is selected! ( Three flats x 3 boxes = 9 Channels!).

Channel flicking Hell or Heaven!

ShaneOC

Originally posted by Muck
Fortunately (for me) the Beebs won't go free till the 14/07 so I have a few more weeks to get me head straight. M

Not sure if this has been confirmed 100% yet.

spongebob

Originally posted by watty
The "earths" are all commoned by the coax outer, which is why all the receivers need to be on same phase, or otherwise you need a single strong earth wire connecing to each receiver, at some pont on the rear of case connected to F-Connector outer.

I can confirm that all are on the one phase (Phase S)

Does that mean they can all earth as normal to the third pin on the plug ?

M

watty

Actually most satellite receivers, VCRs, TVs etc don't use the earth pin which is why they need to be explictly earthed if not on same phase.

You shouln't need to do anything.

If, and only if you get a hum on the HiFi connected to sat receiver when more than one sat receiver is physically connected to coax cable via F-Connector, then you *might* need to run a single earth wire to link all the RCA audio out jack earths.

But as I say you shouldn't need to do anything.

Capt'n Midnight

You won't need a quattro / quad for hotbird if you only want Italian - one LNB Vertical Lo band - pipe to each apartment - this will give you the main italian channels.

HOTBIRD
All the othe itallian channels I can find apart from Sailing Channel (nice weather forecasts & a good moving wallpaper channel) are on Vertical - Hi. Note: many regional channels are in the Hi band so could be problematic if someone wants to see their local programs.

Also RAI 1,2,3 are still on analog so some sky boxes would help here - uhf output - again these are Vertical and Lo band.

A good big dish and you could run three boxes on one old non-universal LNB with a four way splitter - just put 13 V into LNB on the 4th power pass splitter connector. (or rotate the LNB 90 degrees so it needs 18V - and have all boxes providing power via diodes - messy)

================================

You might not need all the Astra bands either....

So you might be able to use 22KHz tones instead of Diseq - though I suspect you will need a quad LNB and one diseq for each receiver.


Have a look at
http://www.satmania.com/eng/satchannels/search/
sort by position langague polarization - most of the other entries come back empty as if their dB has lots of blanks

www.SatcoDx.com - used to have text files - filter in excel
www.lyngsat.com - best info