Communal Dish Mission.

djdeejay · 23-08-2009

Hello everyone,

I have registered and paid for Sky HD in my apartment and Sky are coming 31st of August - prior to then I need to solve the problem with my apartment only having one lnb feed.

I live in strange block of apartments in Chester, I am in a seperate block with just 14 apartments in - the top 7 of which mainly have their own sky digital dishes so as not to use the communal system.

Ive found the dish on the roof which is accesible to everyone, has a quattro lnb and feeds straight down the building (about 8 floors) into the car park in the basement where it joins its multiswitch box.

Im yet to poke around there - but the box is always wide open, I cant quite see in - but i see the four cables in and then all the cables leaving for the apartments. I cannot count the amount yet - tomorrow i shall be up on the ladder to investigate, brands, numbers of leads etc.

I currently have a Sky HD box just viewing the free channels - the quality of signal I admit is not great. I currently have a "booster" from maplin on the cable in my apartment and I have just under 50% of signal strength and exactly 50% for quality on sky.

I traced our cable where it enters the bottom of our apartment, and its about a 35 meter run - but I would estimate its probably 40-45 meters by the time it reaches our wall socket.

If i can find a spare feed tomorrow - which im sure I will, and certainly be able to arrange to use one of a neighbour as no one has sky in the bottom 7 flats - what are the chances with such poor quiality to start with having a working feed?

Ive been told by this link "http://www.satcure.co.uk/accs/stacker.htm" that i need a Johanssen 9639KIT for communal use and not the standard stacker/destacker - is this true? Or will any Johanssen stacker/destacker work when supplied with two feeds from the multiswitch? The reason I express concern at this statement is because I cant actually find reference to the 9639 anywhere on the internet apart from their website!

The 9637 wideband amp is mentioned on the page, to be used at head stage - is this correct? Should i use it just after the multiswitch and before the stacker?

Also - many people say not to use a wall-plate. Obviously all the apartments terminate with a faceplate in the wall. Would i just be able to remove the faceplate and replace with a fconnecter to go straight into the destacker instead?

Using this before the stacker, and then a 60m rather high gain stacker could i even possibly improve the signal from what i currently receive? I dont have any problems on channels - I used to get them on Setanta only.

I will report back when i know more about the multiswitch and what feeds are available and if i can even trace my cable (if they are not numbered i will do my best to trace...finally resorting to just undoing each one to see which is mine - I only have 14 to go through!)

If someone could help with a few of the questions here, and also - the power for the stacker/destacker, do they plug into the stacker end, or the destacker in my apartment?

Look forward to some info and feedback, ive read every thread I can find on the website here to get most of the information I already have - so any input on the questions I have asked would be fantastic.

Kind Regards

**Analoguesat** · 23-08-2009

Do not tinker with the communal system under any circumstances - if you dont know what you are doing could end up stopping it working completely!

You need to get the building management company to deal with it.

Stacker / destacker systems sometimes work, but its bo no means guaranteed to work.

Wiring one into the head end will require all the earth bonding to be correctly done - another reason to leave well alone - if it isnt you could kill someone!.

djdeejay · 23-08-2009

The management company are not even interested in answering calls from anyone they are a joke and to be honest im quite willing to take the risk ive played around with far more dangerous electrical feeds when wiring up electrical system in my restaurant then lnb feeds to a multiswitch!

Anyway thanks for the advice, but if you've got any answers to my questions that would be great

I would have installed a Sat dish on my balcony had it not been out of sight of the satellite by the side of our building being 5 foot too high!

djdeejay · 23-08-2009

Just as a side note - does one of these systems work with a HD box

_http://www.vision-products.co.uk/productpage.asp?productcode=V70-400SCR&subcategoryid=65

After a quattro multiswtich system? Or does it need to be fed with a single lnb feed instead?

Are they more reliable than a stacker/destacker? Surely easier to install in this case too?

**Analoguesat** · 23-08-2009

Im not worried about you killing yourself - if that happens its your own fault.

Im thinking more of the old dear next door who gets zapped because you Got It Wrong when fooling around with the wiring

Anyway - one of the guys who deals with these smatv installs on a day to day basis will probably be along in a bit.

djdeejay · 23-08-2009

Originally Posted by Analoguesat

Im thinking more of the old dear next door who gets zapped because you Got It Wrong when fooling around with the wiring

Dont worry no old people live in the 7 apartments down here, 4 are empty, theres a drug dealer at the end and if the witch gets it next door that'll just be karma - only joking.

Seriously though, i wont be messing around with actual electrical wiring here - just f connectors!

djdeejay · 23-08-2009

Sorry, didnt realise posting the link was not allowed.

It was just to one of the SCR splitters (V70-400SCR to be precise)

Are they better than stackers/destackers, do they work with all the new Sky HD boxes, easier to install?

Would give me a better outcome with 4 signals... be very interested to know if this is a possibility...

**nanochickin** · 23-08-2009

You will probably find that the system is running within specification. Sky states that on a communal IRS system that 55dBuv is enough power to get a picture.

55dBuv won't even show up on a Sky boxes power meter

If there are no spare ports in the cab you can just about forget it, there is no way of doing it if all the output feeds are in use

What type of equipment is it that is in use?

Vision, Triax, Spaun or Fracarro?

If there are spare ports you may be able to use a stacker setup although in past experience it doesn't really work that well with Sky HD

As for pinching somebody elses feed, i wouldn't recommend it.

These systems send Terrestrial, DAB, FM & satellite signals down the same cable. If you pinch somebody else's feed you are probably going to upset someone as they won't be able to watch TV and even more concerning you may end up with a large bill once the engineer has found the problem and ripped out your stacker.

The only advice i can give is don't mess around with stuff that you have no idea how to repair. If you bugger something up your going to end up with a rather large bill

by the way I am available on an hourly basis

Nano

**satelliteman** · 23-08-2009

Originally Posted by djdeejay

The management company are not even interested in answering calls from anyone they are a joke and to be honest im quite willing to take the risk ive played around with far more dangerous electrical feeds when wiring up electrical system in my restaurant then lnb feeds to a multiswitch!

Yes, don't play around with it and call in a professional. If you disturb part of the earth bonding and someone happens to get injured or worse..... well were visit you in prison !

djdeejay · 23-08-2009

Originally Posted by nanochickin

55dBuv won't even show up on a Sky boxes power meter

Strangely ive just check signal now on BBC 1, BBC2, BBC HD and More 4 and all are showing strength as being 1 block under full - quality still 50% though.

Originally Posted by nanochickin

What type of equipment is it that is in use?

Vision, Triax, Spaun or Fracarro?

Not sure yet, as i said in my original post i'll be looking at all this tomorrow.

Originally Posted by nanochickin

These systems send Terrestrial, DAB, FM & satellite signals down the same cable. If you pinch somebody else's feed you are probably going to upset someone as they won't be able to watch TV and even more concerning you may end up with a large bill once the engineer has found the problem and ripped out your stacker.

I dont think these do, comes straight from the Sat dish to the multiswitch - in the apartments we have a UHF which comes in and strangely goes into a booster and splitter in the airing cupboard and is then spread out amongst the rooms. The Sat feed just comes straight from the coax on a single wall socket into the apartment from the multiswitch - no option for DAB, FM or anything else from that socket.

Originally Posted by nanochickin

The only advice i can give is don't mess around with stuff that you have no idea how to repair. If you fook something up your going to end up with a rather large bill

Guys really thanks for the persuation not to do the job, but really, ive worked on far more complicated and dangerous electronic projects that this - so please, no more warnings not to do it! If you can help with some of the questions ive asked which haven't been addressed in the original post that would be great.

And any information about the SCR process which seems to be honest the better solution but I cant get information on loss of gain and how far it can travel anywhere.

It would appear to work with a PACE, Samsung or Amstrad box with the SCR Band option in the LNB setup menu...

**nanochickin** · 23-08-2009

OK lets put this into perspective

stackers 9 times out of 10 don't work with communal IRS systems

If you have high power and low quality its either the dish is out of line or the system is being launched at a much too high level which is causing the MER and noise margin to drop significantly.

If you have a signal that is showing up at 50% there is no need to boost it.

As long as there is a signal quality and signal power showing you will get a picture.

Guys really thanks for the persuation not to do the job, but really, ive worked on far more complicated and dangerous electronic projects that this

I've heard this a million times. These systems are easier enough to setup if you have a meter. Do you have one?

If not you will fook it up and end up with a large bill and still no Sky+.

The system will employ a Quattro LNB which is fed into the multiswitch which is then triplexed with the UHF & DAB/FM signals out to the subfeeds to the properties.

If you haven't got a meter then don't mess with it as you will be guarenteed to mess it up to a point where you will take the whole block out

At which point i charge £50 an hour

djdeejay · 23-08-2009

Originally Posted by nanochickin

At which point i charge £50 an hour

And if you didn't keep trying to tout work for yourself...

I know how these things work, its by no means rocket science, and neither does it require the cost of £50 an hour. I have routed an entire commercial development from scratch from with 220v and 3 phase power...making sure the ground is still on a bought in piece of equipment will not be a challenge.

I didnt want information about how to do it or if i should do it, rather information about some of the questions which are not answered on the forum...maybe theres a reason for that though

No information or knowledge about the SCR process??

**satelliteman** · 23-08-2009

Unless you have spare ports on the switch, neither the SCR or stacker will work.

_http://www.globalinvacom.com/products/pdfs/SCR%20iss4.pdf

djdeejay · 23-08-2009

Originally Posted by satelliteman

Unless you have spare ports on the switch, neither the SCR or stacker will work.

I thought that was the purpose with the SCR though that you didn't need spare ports as such...

You take your feed and three other feeds...those three feeds get fed back out unaffected and your feed gets sent into your apartment where it meets the splitter that puts it into 4 signals...

Anyway ive just had a look, there are two spare feeds - its a 16 way splitter and only 14 feeds...

**nanochickin** · 23-08-2009

Mate i earn more than enough money a week thank you without having to tout for work. Its meant to be humorous hence the smiley like this one ->

I've heard it a thousand times from people in other industries who think IRS equipment is easy to work on, people who i have had to go and put the systems right for after they have messed with it and fooked it up well and truly

Let us know how you get on

Stackers do not work well. The only way to guarantee it will work is to run a second cable to the property which is the correct way of doing it

**satelliteman** · 23-08-2009

Originally Posted by djdeejay

I thought that was the purpose with the SCR though that you didn't need spare ports as such...

Sorry, thinking of the standalone stacker. Of course you will have to disturb other users by disconnecting them to fit the SCR. Also note, the receivers that are compatible with the SCR system on the pdf, more may have been added.

djdeejay · 23-08-2009

Originally Posted by satelliteman

Sorry, thinking of the standalone stacker. Of course you will have to disturb other users by disconnecting them to fit the SCR. Also note, the receivers that are compatible with the SCR system on the pdf, more may have been added.

Indeed they have - bit of research shows that most SKY HD boxes have the feature - not thompsons though!

Doesn't appear many people have installed this system though very little feedback - only a few people saying it worked perfectly for them, but not many systems come up on internet and not many saying how long the cable can be for successful operation compared to a stacker.

Im guessing you haven't installed any SCR systems then nanochickin?

**nanochickin** · 23-08-2009

You mean this

How it works

Each satellite receiver in the installation has a dedicated user band of a bandwidth approximately the same as a transponder. The receiver requests a particular transponder frequency via a DiSEqC-compliant command. A mixer in the dish-end equipment (an LNB or distribution unit) converts the received signal to the correct user band IF centre frequency for that receiver.

The converted transponders of the various users are then combined, and sent via the single coaxial cable to the receivers. The combined signal is tapped or split to reach every user.

Equipment

Special LNBs have been developed for use in single cable distribution systems. All four sub-bands of the Ku band (low frequency/horizontal polarity, high frequency/horizontal polarity, low frequency/vertical polarity, high frequency/vertical polarity) are received by a conventional front end, amplified and downconverted to the L-band, to be fed to a number of Single Cable Router (SCR) chips – one for each user that can be connected - to further downconvert the required section of the received spectrum to centre on the user band IF frequency. The LNB further includes a mixer to combine the user bands together and a microcontroller to receive the instructions as to which frequency is required by each user and control the SCR chips. [3]

Alternatively, a single cable distribution system can use a conventional LNB feeding the four sub-bands to a separate SCR device, as a substitute for a traditional multiswitch, that needs a dedicated coaxial cable for every receiver (or tuner) connected.

Unicable LNBs and SCRs also include either a legacy mode of operation or a legacy output which provides conventional LNB IF for use with an installation of non-Unicable receivers.

A receiver required to operate in a single cable distribution installation can be essentially conventional. It should be able to tune to the user channel (within the normal IF tuning range) and modulate the LNB power voltage with the 22kHz signal required for issuing DiSEqC commands. It will then require only software modification to operate as a single cable distribution receiver.

For correct operation, two-way splitters are required to feed the combined signal to each receiver. These allow bi-directional passage of both RF and DC signals, to provide for the passing of DiSEqC commands between the LNB and receiver(s).

Yes i have helped installing one, and they are a complete pain in the arse

djdeejay · 23-08-2009

Originally Posted by nanochickin

Yes i have helped installing one, and they are a complete pain in the arse

Why, in what way...4 in, 1 out...a stacker would be partially more difficult to install than this, its not soldering mini pots and computer chips onto a motherboard is it!

**nanochickin** · 23-08-2009

They don't have a tendency to work that well over large distances, so you have to use high grade cable as there is a significant problem with signal loss.

The system we installed hasn't been that reliable either due to vandalism. Cut one wire and the whole system goes out.

The company i worked for at the time, Trialled it on one block only to discover it doesn't work that well as most of the tenants receivers wouldn't work with it and like i said before its prone to vandalism

When you are used to working within the confines of 5 and 9 wire IRS systems, it can also be difficult to get your head round how to work with new systems and ideas, hence being a complete pain in the arse

It may be inevitable that they will become more wide spread when the price of equipment comes down, but then again i can see fibre optic technology making it more or less obsolete before it has chance to take off.

SCR is a bit of a no-brainer now with the price of fibre optics dropping as much as they are

Nano

**rolfw** · 23-08-2009

Thread closed, the title of this section very clearly states Domestic systems only and for very good reasons.

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Communal Dish Mission. This section is for discussion on domestic multi-receiver systems for distribution of both terrestrial and satellite signals. Multiswitch, diplexer, triplexer, earct bonding, smart Priority switch, signal splitter, SCART doubler, video sender, remote extender, etc.

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