Poor sky picture/signal quality
Poor sky picture/signal quality
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Discussion

Mars

Original Poster:

10,165 posts

245 months

Monday 11th August 2008
quotequote all
I know tis has been done before, and I've even contributed to one, but I'm at a dead-end.

On some channels, History (529) and some of those in the upper 100/early 200 ranges, I get poor picture quality. Same if I use the interactive channels (BBC and Sky). It's blocky and digitally-noisy.

I've been up the ladder this morning to check the dish and have wiggled it around to achieve the best signal strength and signal quality I can, but the best I could get is what I already had (100% signal strength and about 75% signal quality).

I called Sky's un-helpdesk (obviously in India despite me apparently talking to "Sue") who ignored all my claims of testing and my observations, and simply advised me to reboot (yawn).

I asked whether Sky has a higher gain dish/LNB or simply a larger dish (same thing probably) but could get no technical advice other than "all our customers use the standard one". She did offer the correct angle but was mystified when I asked for the inclination (is that the same as the azimuth or is that the angle of the LNB relative to the dish?). I know that was a technical question but given that it's their business to provide a signal from a satellite I didn't think it was overtly technical.


Anyway, can the sage members of PH offer any picture improvement advice? I suspect I need more gain. There are other Sky receivers in my road. Only about half of them use the same dish as mine (the "seive" version). I'm sure the guy opposite has a different one, slightly larger. Would it help if I simply replace the dish for a larger one, keeping the same LNB and angles?

Plotloss

67,280 posts

301 months

Monday 11th August 2008
quotequote all
Where the F-Connectors connect to the LNB on the end of the dish arm, how are they waterproofed? Properly or with a bit of insulation tape?

Water in the coaxial at the head end is usually responsible as the foam dielectric gets wet and it causes a short.

For a better explanation of angles etc, have a conversation with your local satellite fitter rather than a Sky CS monkey.

Mars

Original Poster:

10,165 posts

245 months

Monday 11th August 2008
quotequote all
Plotloss said:
Where the F-Connectors connect to the LNB on the end of the dish arm, how are they waterproofed? Properly or with a bit of insulation tape?

Water in the coaxial at the head end is usually responsible as the foam dielectric gets wet and it causes a short.

For a better explanation of angles etc, have a conversation with your local satellite fitter rather than a Sky CS monkey.
It's all waterproofed properly with heatshrink - it's the sort with the glue inside to offer better water rejection and to hold it all together more firmly.

I installed it myself using quality low-loss satellite cable. smile

I actually knew the bearing and inclination already but as she offered the bearing I thought I'd double check the inclination.


This isn't a problem were I have a terribly poor picture. It's just not 100% on some channels and with interactive TV. It could be better and I reckon the problem is nothing more than slightly low gain. The dish "points" at clear sky between houses slightly higher than ours. I wonder whether this has any influence... I'm convinced a higher gain dish/LNB would cure it but don't know whether you can simply partner any dish with any LNB. A dish is cheap so I might just have a go... if I can get a recommendation.

agreen

232 posts

288 months

Monday 11th August 2008
quotequote all
Mars

I work for a sky fitting company at the moment and I may be able to help you out. I do not work in the technical department but I will ask someone who does or one of the fitters and see if they can suggest something that will help.

Alex

cjs

11,709 posts

282 months

Monday 11th August 2008
quotequote all
Where are you (Mars?) Unless your way up north then a standard Sky dish will be fine. The only way to align a dish properly is with a meter connected locally to the LNB, you can get a cheap 'screamer' meter from Maplins or similar which will help.

Usually a poor signal results in the pictures freezing and pixelating, is this what is happening.

Remember a lot of the channels available via the Sky platform are poor quality anyway.

oobster

7,711 posts

242 months

Monday 11th August 2008
quotequote all
Weird one to try - I was having some picture problems on some channels too, and the guy @ Sky asked if I had a cordless phone located anywhere near the box. I did, so he said move the phone.

Once I moved the phone to the other side of the room the picture on the dodgy channels (always the same channels - Ch4+1 was one of them) improved and stayed improved.

big_rob_sydney

3,671 posts

225 months

Monday 11th August 2008
quotequote all
Your solution is at www.satkings.org

ITGate TGM220.

Enjoy.

Tony*T3

20,911 posts

278 months

Monday 11th August 2008
quotequote all
Any 'line of sight' issues? Trees or powerlines etc?

Mattygooner

5,304 posts

235 months

Monday 11th August 2008
quotequote all
Try having a digi box, sounds like a Spectrum loading up.

Make sure your dish has a clear path, we had a tree that would occasionally blow in to the path of the receiver and ruin the signal and picture, a chainsaw soon sorted it.


Mars

Original Poster:

10,165 posts

245 months

Monday 11th August 2008
quotequote all
agreen said:
Mars

I work for a sky fitting company at the moment and I may be able to help you out. I do not work in the technical department but I will ask someone who does or one of the fitters and see if they can suggest something that will help.

Alex
Thanks. Any info would be useful.

cjs said:
Where are you (Mars?) Unless your way up north then a standard Sky dish will be fine. The only way to align a dish properly is with a meter connected locally to the LNB, you can get a cheap 'screamer' meter from Maplins or similar which will help.

Usually a poor signal results in the pictures freezing and pixelating, is this what is happening.

Remember a lot of the channels available via the Sky platform are poor quality anyway.
I'm in the Midlands which means I "technically" shouldn't need anything special WRT a dish.

I noted in today's little experiment that my signal strength meter (as displayed by the box itself) actually registered very small increments in both the horixontal and vertical movements. I left it on 100%.

What does "signal quality" mean in this context? How is it measured?

Also, when you say some channels are poor quality already, what do you mean? Can you confirm how good your History channel is (129 and 130) please? If I use the on-screen info, the actual broadcast programme becomes very poor indicating (to me) that there isn't enough bandwidth to cope with the programme and the info.

oobster said:
Weird one to try - I was having some picture problems on some channels too, and the guy @ Sky asked if I had a cordless phone located anywhere near the box. I did, so he said move the phone.

Once I moved the phone to the other side of the room the picture on the dodgy channels (always the same channels - Ch4+1 was one of them) improved and stayed improved.
They asked me the same question. Our cordless phone is already in a different room.

Tony*T3 said:
Any 'line of sight' issues? Trees or powerlines etc?
There are houses at a higher elevation from our house in the path, but not *quite* so high as to be within the line of sight. Also, the two houses are slightly either side of the "path" too.

There are trees nearby, but again not quite in line of sight (I checked before installing the dish there).



Besides all this, we have (according to our box) 100% signal strength. It's just the signal quality which is at about 75%.

Also most of our channels are 100% perfect. It's just a few which are poor, and especially any interactive viewing which is pixellated to watch and "chirpy" to listen to. This is particularly irritating as my wife wishes to watch the various output for the Olympics.


Thanks for all of the suggestions. I'm very tempted to see if I can uy a dish supposed to be used "in the North" to see if there's any difference.

V8A*ndy

3,703 posts

222 months

Monday 11th August 2008
quotequote all
Seems to me your LNB is on its way out. The signal strength meter on your Sky box only measures the strength at one particular frequency and polarisation.

The horizontal channels may be fine and the vertical channels a bit weak (or the other way around). Buy a new one from Maplins and if it's still the same you can always return it.

ETA This also overloads the processing capability on some older boxes.



Edited by V8A*ndy on Monday 11th August 21:44

talkssense

1,441 posts

233 months

Monday 11th August 2008
quotequote all
100% and 75% soundspretty goodto me. i've certainly seen no problems with less than that.

How old is your box? The problem with interactive stuff sounds like it maybe the box is unable to process the info quickly enough.


convert

3,757 posts

249 months

Monday 11th August 2008
quotequote all
When you lose signal try the following

Go into Services from your remote.

Press 4 0 1 Select

It should take you onto the 'hidden' installer menu.

Choose option 1 for LNB setup.

Go down and turn off the LNB power supply, and the 22KHz command

Save the settings. This will reset the LNB.

Then go back into LNB setup and turn them both back on, and save the settings.

You can then exit the menu.


I've got a similar problem with my Sky setup, where certain channels pixelate, or even freeze and produce a little white noise. It's probably some water ingress into the LNB, but I can't be bothered changing it.

Mars

Original Poster:

10,165 posts

245 months

Monday 11th August 2008
quotequote all
talkssense said:
100% and 75% soundspretty goodto me. i've certainly seen no problems with less than that.

How old is your box? The problem with interactive stuff sounds like it maybe the box is unable to process the info quickly enough.
Box is probably 13 years old. It's a Panasonic.

Mars

Original Poster:

10,165 posts

245 months

Monday 11th August 2008
quotequote all
convert said:
When you lose signal try the following

Go into Services from your remote.

Press 4 0 1 Select

It should take you onto the 'hidden' installer menu.

Choose option 1 for LNB setup.

Go down and turn off the LNB power supply, and the 22KHz command

Save the settings. This will reset the LNB.

Then go back into LNB setup and turn them both back on, and save the settings.

You can then exit the menu.


I've got a similar problem with my Sky setup, where certain channels pixelate, or even freeze and produce a little white noise. It's probably some water ingress into the LNB, but I can't be bothered changing it.
I'll have a go and let you know if it's improved things.

When I was up the ladder earlier I noted that the LNB was perfectly dry and displayed no signs of there being a water-ingress issue.

agreen

232 posts

288 months

Tuesday 12th August 2008
quotequote all
I spoke to some of the engineers at work yesterday and they suggested that you may have signal strength of 100% and quality of 75% but the 75% would only be measured on one LNB frequency/feed, so all the others might be considerably lower than that figure - thus offering a potential reason for the lack of channels. What sort of LNB do you have installed, is it standard or is it an LNB that supports sky plus? If you were in the South East I could have offered the assistance of one of our fitters on the way back from a job to look at it but obviously as you are in the Midlands that is a good distance away from where we operate. If you are still stuck PM me with what area of the midlands you are in and I will send you the contact details for reputable installers in your area if that would help.

Mars

Original Poster:

10,165 posts

245 months

Tuesday 12th August 2008
quotequote all
Thanks for the info. I have a standard LNB (no Sky+) and I live in Redditch.

I am tempted to buy a new dish and LNB given that this one is about 14-15 years old now.

Thanks.

Mars

Original Poster:

10,165 posts

245 months

Tuesday 19th August 2008
quotequote all
Resolved with a Zone 2 dish. 100% signal strength and at least 90% signal quality. No digital interference or pixellating now on any normal channel or on the interactive channels.

Morningside

24,147 posts

260 months

Tuesday 19th August 2008
quotequote all
This thread reminds me of an odd fault I had a couple of weeks back.

After swapping LMBs, Sat boxes, realigning dish. etc. etc. etc. Turned out that the dish itsself was bent out of shape!

Very odd error. Gave very strong signal yet very low quality.

Silent1

19,762 posts

266 months

Tuesday 19th August 2008
quotequote all
I replaced my (sky installed) single LNB with a Quad LNB a couple of months back when i bought one of the new Sky+ boxes.

The signal used to go in heavy rain etc, now it's perfect with 100% on both aerials.
It didn't help that the sky LNB could flap around on the arm meaning it didn't stay at the right angle, whereas the new one is nice and snug.