Channel 4 Breakup / Pixelation

[garym71]

At the weekend I replaced my Sky minidish with a Raven Gemini 70cm mesh dish. This is ultimately in preparation to mount some additional LNBs for other satellites but for the time being it is just set with a single ouput LNB pointing directly to 28.2E for my Sky receiver (a Panasonic DSB30). The LNB is an MTI 0.2db universal one.

It is only tonight that I have spent any real time viewing Channel 4 and I have noticed quite a lot of breakup / pixelation. This doesn't seem to happen on other channels I've tried. I'm based in the south of the UK and the weather outside is fine.

I set up the dish with a signal meter and it was pointed manually using azimuth / elevation angles that give the best signal stength on the meter. I also adjusted the LNB skew to get the the best signal I could. The Sky box signal test menu shows 100% signal strength and 80% signal quality which is the same as I had with the Sky minidish.

Is there something paricularly weak about the Channel 4 signal and is there anything I can do to try and rectify this problem? I thought the larger dish should actually make things better, not worse

[snap]

This could be a sign of the receiver starting to fail. The power supply may be on the way out, loss of high band channels is a symptom.
Try swapping the receiver for another known to work OK, preferably a newer model.

[garym71]

OK. Thanks for taking some time to reply I'll try and find a spare box I can borrow from someone to at least try and confirm or eliminate the receiver as being a cause of the problem.

It just seems a bit of a coincidence that everything was fine last week using the Sky minidish and then this week after having swapped over the dish & LNB for different ones that I start getting a problem.

You say "high band channel". I'm afraid I'm still a bit of a novice at the moment and still learning so I'm not entirely sure what "high band channel" means. Can you possibly expand a little further please.

Also, if my problem is possibly related to high band channels then are there any other channels in the high band range that I can also check to see if I'm getting the same issue on those as well?

[rolfw]

http://www.lyngsat.com/packages/skyuk.html should give you a good selection.

High band are those over 11,700

[snap]

It is really worth trying another receiver if only to eliminate this possible cause.
Also check the connections, do you have a wallplate outlet?
High band means high frequency.

[garym71]

I've managed to source another box to try temporarily so I'll give that a go at the weekend. The only thing is that Channel 4 is on videoguard encryption so I'm assuming I won't be able to try that out on another box unless I get my viewing card linked to the replacement box which I obviously don't want to do as it's not my box. I know that I've tried my viewing card in a different box some years ago and just got a message on the screen saying to insert the correct viewing card. I guess I'll find out at the weekend if my card will actually work in the other box.

I see that Channel 4 is pretty high up the frequency range, in fact probably the highest frequency channel from the ones I actually watch on a regular basis. I'll try some of the other free-to-air channels around the same frequency on my current (possibly faulty) box because at least I'll be able to compare those on another box without too much hassle.

[denis1501]

Channel 4 will clear in any box m8, don't worry.
Only premium channels are paired.
regards
D.

[garym71]

Thanks Denis, that's good news. I won't have access to the other digibox until the weekend so I'll be trying it then.

In the meantime, last night I tried numerous other channels around the same frequency and on various higher frequencies but the only other channel that geve me some very minor breakup (although nothing compared to the breakup I'm experiencing on to Channel 4) was the "BEN" channel (on 12523 H). However, none of the other channels on the 12523 H frequency gave me any problems at all

Unfortunately Channel 4 is the only channel broadcast on 12168 V so there are no other channels for me to try on that frequency

So, the problem really does just seem to be confined to Channel 4 on 12168 V which does make me a little pessimistic that another box will actually resolve the problem but I will try it anyway and report back the results once I've done so.

[garym71]

Just a quick update to conclude this problem...

On Friday I swapped my Panasonic DSB31 for a Panasonic DSB40 that I borrowed from someone. Initially Channel 4 wouldn't work with my viewing card inserted into the DSB40 (I just got a blank blue screen) but an update to the receiver software resolved that problem. The result was that with the DSB40 there was no longer any breakup on Channel 4. I plugged my DSB31 back in and although there was still some breakup on Channel 4 it wasn't as bad as before. So it seemed that I had a dodgy digibox

Anyway, I bit the bullet and decided to get a new box to replace my apparently faulty one and also upgrade to Sky+ in the process so I ordered a Pace TDS470N box.

During the weekend I did put some new cables to my dish for the other LNBs and also decided to replace original cable to my Sky box (plus a second feed in preparation for the Sky+ box). After renewing my cables and plugging my original DSB31 back in I no longer seem to get any breakup at all on Channel 4

I can therefore only guess that the problem was actually an issue with my DSB31 not liking the original cable (about 6 years old) in conjunction with the different LNB/dish that I fitted last weekend. Prior to that on the old Sky minidish with the original cable and DSB31 everything was fine.

Anyway, looks like I'm getting a new box now whether I need it or not At least I will now have Sky+ features though so it wasn't all in vain