Weird signal quality issue???

thenobody

Hi

Firstly the setup.
I live in an apartment which has a communal system for sky.
Sat dish is on the roof and uses a quattro lnb, cabled down to the plant room in the basement. The vertical high, vertical low, horizontal high, horizontal low and terrestrial cables come down into a Spaun brand Launch amplifier.
this then goes out to a Spaun brand multiswitch that feeds off to multiple apartments - two feeds to each.

Have Sky HD in one room and Sky + in another and use a switch box for each feed in to decide where i want to send the signals.
Signal 1 in --> HD#1 Plus#2
Signal 2 in --> HD#2 Plus#1
This is so i can have signal one to both at same time and can have anytime working on both. I just switch over the signal two to whatever box i want to record on when in standby.

Since a couple of weeks ago both boxes are showing on both signals i have zero signal strength and 10% signal quality (this fluctuates sometimes between zero signal quality and 20%)
Everything works fine. I get all the channels with no issues and no noticable quality loss or breaking up etc. HD channels still look superb.

Thing is, when i set a channel to record (on signal one) the signal strength then shows 50% and quality around 60% - which was the previous normal values.
Now signal two is still at 0 to 10% quality and i am browsing using that whilst signal one records.
When I set signal two to record too it also changes to show 50% strength and 60% quality. (transport stream seems to then be different but all channels work and there is no issues)
When i stop the recordings the relevant signals again fall back to 10% quality.

Recordings are fine and no issues.
Happens on the HD box and the Sky + box.

I have also been having an issue with the HD box that there is no EPG music sometimes. Just thought was an issue with the HD box itself.

Anyone know why this is and is there really a problem?
Have you seen or heard of this before?

Thanks
Steven

Darth Maul

Firstly take out the switch box and see if it makes any difference,
then you have to find out if all 4 feeds are affected ( eg, high, low, horizontal and vertical) by using the manual tuning method in the installer menu, if they are I would suspect the dish has moved.

easy way to find out that is to bypass the amplifier and multiswitch.

I would suspect the multiswitch as the quality goes back to normal when recording, so the problem is only happening on the particular band that the default transponder is on.

thenobody

Thanks.

I have removed the switch boxes and cabled directly and is still the same.

Found out that the when i set a signal recording it shows the status of that particular channel. So when i record rte one i get the 60% quality.
Otherwise it shows the default transponder quality.

Ill try the manual tunning you suggested to see that status of each band.

I cant really bypass the amp and switch. The amp takes in the four bands and the switch combines them into the one cable up to my apartment.

thenobody

Bit of further info:-

Disconnecting and moving my dect phone away had no affect

I then went to the manual tuning section and through most different ranges of frequencies and settings (high band low band and verticals and horizontals) for all the channels from this site http://www.ddelec.com/engdig07.htm

All are giving the exact same - no signal strength and about 10 to 20% quality.

The only channel (of real interest out of three) i cant get any signal on is Paramount +1 or anything else on 11546 H 27500 2/3.
Everything else is fine.
11508 H next below this and 11585 H next above this come through fine like everything else. Weird.

I am getting the signal strength increasing to 50% and quality to 60% on the inputs when i set a recording on the particular input. When both recording both jump up.

Has this been seen before?
Would much appreciate your opinions further on this

Sam Radford

The Thomson HD boxes are dropping like flies with power supply problems. I wonder if this is an early warning symptom? What happens if you unplug the Digibox from the 230v power socket and let it cool down for a few hours?

(If the power supply is failing, this could make it a LOT worse, so don't do it unless you are prepared to be without Sky for a few days while you order a replacement PSU!)

thenobody

Well if thats the case then its still under warrenty and sky should replace the PSU or box for me.

I have had to disconnect the supply a few times. Last night signal two wouldnt lock on it. It would on the sky plus box. Just unplugged the HD box and rebooted it and it came back.
Thats fine but if i have something set to record and it wont lock signal two then thats a different matter.

However i doubt it is a problem with the HD box however as I am seeing the same things on the sky + box in the other room.

thenobody

So which do you think is the true signal quality?

the one shown whilst recording?

What would typically be expected with zero signal strength and 10% quality?
I am not seeing any pixelation or freezing or sound breakups.

Thanks

Zaphod

http://www.wrightsaerials.tv/Articles/satellite%20distribution%20pages%2011%20to%2020.pdf

As long as the picture is stable, it doesn't matter what measurements the Sky box registers.

thenobody

Thanks very much for that. Very interesting.

Particularly the line amplifiers as i have order one off ebay to add to one of my line feeds just after the multiswitch - just to see if it improves things.

I talked to a neighbour (feed from a different multiswitch however) who is seeing on their Sky+ box signal quality around 50% in signal one and 75% on signal two so i guess it may be some interference along my feeds and not in fact something up with the dish (thankfully)

Zaphod

thenobody wrote: »

Particularly the line amplifiers as i have order one off ebay to add to one of my line feeds just after the multiswitch - just to see if it improves things.

Putting a line amplifier just after the multiswitch is a bad idea for a number of reasons, some of which are outlined in the article above. Why not leave well enough alone?

thenobody

Well he did recommend adding them on each of the four feeds before the multiswitch but im not gonna buy four of them and get no money back from the other residents.
There is very long cable runs in the place - down about 5 storeys to the launch amp and mutiswitch then back up about 3 to my place.
They are recommended for long cable runs and to be put near the source as possible.
So i guess ill try it at my feed off the multiswitch and also at the feed into my apartment. If it does nothing then just remove it.
Best I can think of at this point, other than getting someone in to make sure the dish is aligned correctly. But that would have to be someone familiar with communal systems and it would end up being me paying for it all too for everyone. Will have to look into it.
Thanks

Zaphod

thenobody wrote: »

Well he did recommend adding them on each of the four feeds before the multiswitch but im not gonna buy four of them and get no money back from the other residents.

Yes, before the multiswitch and under specific conditions. Not after the multiswitch. Have you checked if the existing multiswitch has an in-built amplifier?

thenobody wrote: »

They are recommended for long cable runs and to be put near the source as possible.

Putting a line amp near the source is one thing you're advised never to do.

thenobody

Oh right.
ok

Thanks for the info. Ill rethink it.

Multiswitch doesnt have an amp but their is a launch amp just before it