Combining sat and saorview on one cable problem

clansman

Hi,
I have this aerial in my attic. I am using channel 21 (Mullaghanish) and I receiving a signal quality of 90% and signal intensity of 78% on my HD reciver

I have since added a tv in the bed room so i bought this
I also want to combine a sat signal with the saorview signal for the bedroom(only one socket on the wall) so I bought this well I bought 6 of them.
I have everything step up with only a small loss of signal for saorview however when i connect the sat cable to the HD receiver it kills the saorview signal, well in fact it kills the box as well. So i got my multimeter and checked for continuity between the pin the and the shield of the sat cable. Sure enough they were connected. So i changed both satellite combiners but still no joy. I tested the cable from the LNB and its ok
I am at a loss as to what is going on,
Any ideas,.
should i be using power pass splitter and combiners?

Peter Rhea

clansman wrote: »

I have everything step up with only a small loss of signal for saorview

You've split the signal 4 ways, that isn't a small loss no matter what your receiver's display tells you.

however when i connect the sat cable to the HD receiver it kills the saorview signal, well in fact it kills the box as well.

What exactly do you mean by 'kills the box'?

should i be using power pass splitter and combiners?

Presumably you're combining the terrestrial & satellite signal after the 4-way splitter?

clansman

Peter Rhea wrote: »

What exactly do you mean by 'kills the box'?

What is should have said was that sometimes the kills the power to the box. ie the box turns off.
While other times the signal quality for saorview drops from ~85% to exactly 58%

Both HD receivers work in the sitting room(i.e. one cable straight from sat and the other straight form splitter -saorview)

Peter Rhea wrote: »

Presumably you're combining the terrestrial & satellite signal after the 4-way splitter?

Yes

SalteeDog

I trust you have ruled out a problem with the cable running from the wall splitter to the satellite receiver? i.e. perhaps short in one of the F-connections. Maybe that's what you mean when you say when you say you tested the cable from the LNB ?

Peter Rhea

So the signal path from the aerial is: aerial - - -> 4 way splitter input - - -> 4 way splitter output - - -> combiner terrestrial input - - -> wall outlet? - - -> to 2nd combiner & split out satellite & terrestrial.

What kind of wall socket is involved?



There have been other threads on the subject of terrestrial signal loss with these types of combiners but if anyone has found an answer to their problem, they've never bothered posting back to say so.

championc

Something like this ??

http://www.boards.ie/vbulletin/showpost.php?p=69210372&postcount=17

zg3409

clansman wrote: »

Hi,
I have this aerial in my attic. I am using channel 21 (Mullaghanish) and I receiving a signal quality of 90% and signal intensity of 78% on my HD reciver

I have since added a tv in the bed room so i bought this
I also want to combine a sat signal with the saorview signal for the bedroom(only one socket on the wall) so I bought this well I bought 6 of them.
I have everything step up with only a small loss of signal for saorview however when i connect the sat cable to the HD receiver it kills the saorview signal, well in fact it kills the box as well. So i got my multimeter and checked for continuity between the pin the and the shield of the sat cable. Sure enough they were connected. So i changed both satellite combiners but still no joy. I tested the cable from the LNB and its ok
I am at a loss as to what is going on,
Any ideas,.
should i be using power pass splitter and combiners?

I am not sure you understand what is needed



The red cable is the single cable to the bedroom.

You need two diplexers per single run between LNB and receiver.

Try to draw a diagram of how you are using 6 diplexers?

The power pass side should only be connected to the satellite receiver, or LNB on dish NEVER a TV nor TV amplifier.

SalteeDog

Sounds like the power-pass splitter he has (and is referring to in his post) is of the type you use for UHF/VHF only eg. for use with a masthead amp (or indeed for a sky-eye). The LNB should not be connected to that.

Peter Rhea

zg3409 wrote: »

Try to draw a diagram of how you are using 6 diplexers?

He said he bought 6, not that he's using them all atm.

SalteeDog wrote: »

Sounds like the power-pass splitter he has (and is referring to in his post) is of the type you use for UHF/VHF only eg. for use with a masthead amp (or indeed for a sky-eye). The LNB should not be connected to that.

The diplexers should be downstream of the 4 way splitter. Let him post back with details of the wallplate.

clansman

zg3409 your spot on. apart from one thing i have a splitter on the cable form the aerial to supply the sitting room and bedroom(via combiner)
I bought 6 TV Aerial & Satellite Combiner so that I do the same for the kitchen and maybe another bedroom. I am only using 2 TV Aerial & Satellite Combiners.


Peter Rhea
Its a standard wall socket with only one coaxial connection. i'll take a picture of it tonight.

Peter Rhea

Unless the socket has an f-connector, I wouldn't use it for satellite. It may even be the isolating type that blocks the DC supply to the lnb.

You'd be better off with something like this (incorporates sat./terr. splitter) or just remove the innards of the plate you have & pull the cable through the hole, if possible. Then you can use an f-connector to the sat./terr. splitter.

iba

Hi,

I may be way off track but could you not just use one of these:

http://www.amazon.co.uk/Satellite-Outlet-Freesat-Aerials-Satellites/dp/B002XUXAH0/ref=sr_1_1?ie=UTF8&qid=1334155914&sr=8-1

and thus avoiding all the splitting?

Regards

Iba

clansman

Hi iba and Peter Rhea,
I have only one cable in the wall. So that option is not available to me. I might have to run an extra cable down the wall but I am only renting so i want to keep work/cost to a low.

iba

Peter Rhea wrote: »

Unless the socket has an f-connector, I wouldn't use it for satellite. It may even be the isolating type that blocks the DC supply to the lnb.

You'd be better off with something like this (incorporates sat./terr. splitter) or just remove the innards of the plate you have & pull the cable through the hole, if possible. Then you can use an f-connector to the sat./terr. splitter.

iba

clansman wrote: »

Hi iba and Peter Rhea,
I have only one cable in the wall. So that option is not available to me. I might have to run an extra cable down the wall but I am only renting so i want to keep work/cost to a low.

Clansman,

In that case why dont u just use the cable coming down through ur wall for the LNB and get a Rabbits Ear Antena and plug that straight into ur STB.

Thats what I do and I got the Rabbits Ear for about €12 in Lidl - works perfect.

Maybe something like this:

http://www.amazon.co.uk/digiTop-Amplified-Performance-Freeview-Wideband/dp/B001ACV7E0/ref=sr_1_2?ie=UTF8&qid=1334157939&sr=8-2

not sure if this is 100% the correct one but Im sure peter and some of the more knowlegeable guys cn confirm.


Regards

Iba

clansman

Peter Rhea wrote: »

or just remove the innards of the plate you have & pull the cable through the hole, if possible. Then you can use an f-connector to the sat./terr. splitter.

I will try that tonight.

Peter Rhea

clansman wrote: »

I have only one cable in the wall. So that option is not available to me.

The wallplate I linked to has the satellite/terrestrial diplexer built in. It only needs 1 cable feeding it with the combined signal.

clansman

iba wrote: »

Clansman,

In that case why dont u just use the cable coming down through ur wall for the LNB and get a Rabbits Ear Antena and plug that straight into ur STB.

Thats what I do and I got the Rabbits Ear for about €12 in Lidl - works perfect.

Regards

Iba

I have thought of that but i just want to know why zg3409 pic doesn't work for me.

clansman

Peter Rhea wrote: »

The wallplate I linked to has the satellite/terrestrial diplexer built in. It only needs 1 cable feeding it with the combined signal.

Ah I see.
I am going to by pass the socket tonight and if that doesn't work I'll get the new wall plate. cheers

iba

clansman wrote: »

Ah I see.
I am going to by pass the socket tonight and if that doesn't work I'll get the new wall plate. cheers

Clansman,

I bought wall plates on Ebay - they only costed about £3 from the UK - cant open the link here in work though.

Regards

Iba

Ronnie Raygun

clansman wrote: »

I am going to by pass the socket tonight and if that doesn't work I'll get the new wall plate. cheers

If you manage to remove the wall plate & connect the cable feeding it directly to one of your combiner/splitters & it still doesn't work, then I'd doubt a new wall plate will make any difference.

The existing plate is by far the most likely cause of your problem though.

clansman

Ronnie Raygun wrote: »

If you manage to remove the wall plate & connect the cable feeding it directly to one of your combiner/splitters & it still doesn't work, then I'd doubt a new wall plate will make any difference.

The existing plate is by far the most likely cause of your problem though.

That's a fair point. I'll get back tonight with a picture of the socket and an update on whether the by pass worked.

zg3409

Also there can be a short in the cable and Saorview may still continue to work, but Satellite will not. It may seem mad but often the TV continues to work with a short on the cable. Not so much with Satellite!

clansman

Update,
I removed the socket and wired directly to the combiner.
below is the pic of the socket
Front

Back


And I pic of the socket bypassed


However I still cant get it working...
This pic is the signal when the sat cable is disconnected


but when I connect the sat cable i get this


Something new has happened the sat is working! so i can get all the BBC's ITV's etc and the HD channels, but no UHF saorview channels.

This pic show the setup in the attic

A=Sat cable from LNB
B=Saorview cable from splitter to sitting room
C=Cable to master bedroom containing but sat and saorview
D=Cable from saorview aerial
also you can see the link cable from the splitter to the combiner.

What I am going to do over the weekend is check all the connections to make sure that no shorts exist.

Peter Rhea

Take the 4-way splitter out of the equation & see if that makes any difference.

clansman

Peter Rhea wrote: »

Take the 4-way splitter out of the equation & see if that makes any difference.

I'll try that this evening.

SalteeDog

Interesting. I've a very similar setup myself - although the 4-way splitter I use does not have a power-pass leg. I did bypass the wallplate and use satellite grade cable for all connections.

So out of interest I've just checked what effect the satellite receiver has on the saorview signal quality,

For RTE1 on Maghera (690 MHz)
Sat receiver off:
Strength = 40%
Quality = 90%

Sat receiver on
Strength = 40%
Quality = 66% or 80% depending on the Sat channel transponder selected. Picture stays perfect though ...because it hasn't fallen off the digital cliff edge..

To avoid confusion - these are readings on my Saorview box.

in any case - what it means (and probably no surprise) is that an active satellite signal will degrade the terrestrial digital signal when both are run over single cable using diplexers.( I assume that is normal but folks here can correct me). My signal quality drops to 66% (good enough picture) but yours drops to 58% (too low for picture). The difference between your set up and mine could be:-
- quality of diplexers
- quality of cable
- length of cable
- other factors the experts here will know about. (Perhaps the fact that you are running your DTT signal via the powerpass leg of the 4-way splitter plays a part?)

Johnboy1951

in any case - what it means (and probably no surprise) is that an active satellite signal will degrade the terrestrial digital signal when both are run over single cable using diplexers.( I assume that is normal but folks here can correct me). My signal quality drops to 66% (good enough picture) but yours drops to 58% (too low for picture). The difference between your set up and mine could be:-
- quality of diplexers
- quality of cable
- length of cable

Can you add the details of the diplexers you use please?
I have been considering doing this for existing cable runs to a couple of locations.
Thanks.

SalteeDog

I use Triax diplexers:-

http://cpcireland.farnell.com/triax/340110/vhf-uhf-satellite-combiner/dp/AP01305

My TV splitter is one of these

http://www.tvtrade.ie/passive-4-way-tv-splitters.html

clansman

final update.
I removed the splitter and this is what i got
http://www.boards.ie/vbulletin/picture.php?albumid=2072&pictureid=12514

So i removed the sat signal from the first combiner.
as you can see, the signal improved!!
http://www.boards.ie/vbulletin/picture.php?albumid=2072&pictureid=12518


At this stage i knew it will never work unless I install new cable...
So I removed both splitter's and ran an extra cable down the wall(after a lot of hassle)



As you can see it worked.
http://www.boards.ie/vbulletin/picture.php?albumid=2072&pictureid=12518
http://www.boards.ie/vbulletin/picture.php?albumid=2072&pictureid=12517




So I came to the conclusion that the cable that joins both combiners is of poor quality. Also when combining sat and UHF there will be signal loss.

As SalteeDog said

in any case - what it means (and probably no surprise) is that an active satellite signal will degrade the terrestrial digital signal when both are run over single cable using diplexers.( I assume that is normal but folks here can correct me). My signal quality drops to 66% (good enough picture) but yours drops to 58% (too low for picture). The difference between your set up and mine could be:-
- quality of diplexers
- quality of cable
- length of cable

zg3409

An interesting test would be to now test the Diplexer on the new cable on it's own to confirm 100% that the cable was the main stumbling block, but I'd say you would rather take a rest at this stage!

clansman

zg3409 wrote: »

An interesting test would be to now test the Diplexer on the new cable on it's own to confirm 100% that the cable was the main stumbling block, but I'd say you would rather take a rest at this stage!

I would love to keep going but my lungs wont hold out(attic was recently insulated!)
and also I haven't seen the girlfriend in the last 5 days and we live with each other!


I'll hope to be doing the kitchen in the coming months. This will be a bigger test as I live in a 2 store house
and it will be next to impossible to route a second cable down the wall.(the bedroom socket was near the ceiling)

so watch this space!

SalteeDog

You may need to put an amp in for the aerial (or perhaps a second aerial in the attic) - for the downstairs room the extra signal gain could make the difference to get you over the gap.

Peter Rhea

clansman wrote: »

So I removed both splitter's and ran an extra cable down the wall . . .
. . . So I came to the conclusion that the cable that joins both combiners is of poor quality.

Strange conclusion to reach, I don't think you can blame the cable for introducing lnb noise (or whatever), I think the diplexers are the culprit here.

I suggested removing the 4-way splitter to see how the terrestrial signal would cope when it's at a decent level & it certainly seems to have helped. As I pointed out in my 1st reply, a 4-way split is a considerable drop in signal level, no matter what the receiver display says.

1dave

why didnt u just wire a sky box or 2 in the attic and use its rf2 to send the analogue signal through the existing wireing and put a magic eye on it. if its only 1 extra room and its ur bedroom you wouldnt even need an amp magic eye and second sky + magic eye and a few connectors 35 euro

Kenny Powers

What sort of LNB do you have are you running 2 Combo boxes? I only see one feed from the LNB in your picture?

Peter Rhea

1dave wrote: »

why didnt u just wire a sky box or 2 in the attic and use its rf2 to send the analogue signal through the existing wireing . . .

Tvs deserve to be fed something better than Sky box RF in this day & age; even RGB scart is a big improvement, never mind HDMI.

I think the OP just needs to amplify his signal enough to compensate for the splitting losses & overcome what seems to be interference coming from the satellite side of the diplexers (they seem to work fine with the unsplit aerial feed, even though signal quality is better without the sat. feed connected).

1dave

i understand that but if you are in a rented house and its not new it wont have shielding on the cable. and so can get interference on the sat side.
in most cases people have 1 big tv and any other tv will be 20 to 28 inch so it wont be that noticable (an rf pic). and its cheap.
hd channels. all 5 of them. i have a 42 connected to a sky+hd box and use scart cos when a switch on the sky box it turns the tv on to scart channel. i can see the difference put its not much. on a blue ray i can see a bigger difference cos its 1080. sat signal is uk is only sent at 780 i think put its not a blue ray anyhow.
all these combo boxes dont update on have interactive. i heard the olimpics will have 20 channels for the the games. on the combo box its scanning again or getting it off some1 else.no epg. the sky box u plug and go and it works the tv too. cheap and no messing around. thats all . its only an opinion at the end of the day. my opioion is sky box and the money you save from the combo put it to a new saorview tv. the new triax 180. a new 32 inch tv 270 + 30 for sky box.

Ronnie Raygun

Dave, the OP here asked for help with delivering a decent signal to 2 HD combo boxes he already owns.

I don't think it's very helpful to be talking about putting Sky boxes in the attic. The already installed coax cables don't seem to be the cause of the trouble in this case anyway.