Transponder problem

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Rikkitic

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#240756 24-Sep-2018 12:58

I have been having trouble tweaking my LNB settings and would appreciate any help. I get good signal (quality reading +55%) on D2 and IS19. On D2 I can receive all satellite channels without problem. On IS19 I have good reception of Arirang and other channels on higher transponders, but I can't seem to get anything on the one I want (frequency 12286 on Lyngsat). This is the one with the bundle including Euronews, France TV, RT. This has worked for me in the recent past but now I can't seem to find it at all. I used Arirang to position the LNB to the best signal and then tried repeated transponder scans while gradually rotating the LNB. My receiver does not see a transponder at 12286 but it does see one at 12287, which I assume is the correct one. But I still can't get any channel.

I only have an 80cm dish and am receiving IS19 with an offset LNB, but this has always worked well in the past. Can anyone help me with this? Has something changed at the transponder end?

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Oblivian

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#2095521 24-Sep-2018 14:03

They can't tend to change anything at the TP end as you put it short of turning them on/off or selling them to a different provider to use as capacity.

Local number differences tend to come down to LNB/decoder shift or alignment

That sucker was damaged on deployment and has never run at full power, and as I understand is part the reason for needing a larger dish from here and parts of australia. And pretty sure offsetting the LNB partly reduces the available reflector size/focus as a result

You also haven't confirmed if you have a DVB-S2 capable receiver.. Noting those particular ones are S2?

Rikkitic

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#2095584 24-Sep-2018 15:07

Yes, my receivers are DVB-S2. I know frequency readings on devices can drift a little and am not bothered by that but I don't know exactly how things work at the satellite end, hence my quest for information. I did not think anything would have changed but the way to find out is to ask. I was thinking of possibilities like slight changes to the beam angle or maybe a drop in signal strength. The problem I am wrestling with is it used to work fine here, now it doesn't, and I am trying to figure out what could have changed. I know a one metre dish is supposed to be the minimum, but my 80cm with offset LNB has worked well in the past so why shouldn't it now?

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tripper1000

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#2095605 24-Sep-2018 15:51

If you are getting the higher transponders OK and seeing the target transponder, I'd be thinking either:

1) They're transmitting a blank signal - check back later.

2) Your receiver can't demodulate the video (ie something has changed since your last tried). For eg. on IS19 I see a blank transponder for all the NINE channels cos my receiver doesn't do multi-stream.

3) You are not seeing the FTA transponder you think you are ie LO freq is wrong. Are the higher transponders appearing at/near the correct freq or are they way off?

Rikkitic

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#2095704 24-Sep-2018 18:28

I'm not sure what is going on. I didn't have this problem before. I have seen a few blank signals, but not these. I also don't have multi-stream but my receivers are S2. There is some frequency drift but they are not that far off. Initially I had no problem at all finding the right transponder but now I can't see it at all. I am sometimes able to get a large number of South American channels but they are marginal. They may be feeds. Lyngsat doesn't mention them and I'm not sure of the frequencies.

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Apsattv

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#2095866 25-Sep-2018 00:59

Rikkitic:

I'm not sure what is going on. I didn't have this problem before. I have seen a few blank signals, but not these. I also don't have multi-stream but my receivers are S2. There is some frequency drift but they are not that far off. Initially I had no problem at all finding the right transponder but now I can't see it at all. I am sometimes able to get a large number of South American channels but they are marginal. They may be feeds. Lyngsat doesn't mention them and I'm not sure of the frequencies.

Please check lyngsat iNTELSAT 19 page again i've sent him an update for 12286 H

https://www.lyngsat.com/Intelsat-19.html

also make sure you are using the correct SR

The 12726 h transponder will load the easiest as it is DVB S

Did you try a blindscan search?

All the TV PLus channels are FTA at the moment

Rikkitic

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#2095941 25-Sep-2018 08:24

Thanks for that. At least it makes more sense now. I am getting everything on the list except the things I want. Typical. No trace of Euronews, RT or France TV. Everything else is there but the signals are weak. I have tried blindscan and even deleting and rescanning the transponders but I still can't find the signals that used to work.

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Apsattv

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#2096489 26-Sep-2018 03:59

Rikkitic:

Thanks for that. At least it makes more sense now. I am getting everything on the list except the things I want. Typical. No trace of Euronews, RT or France TV. Everything else is there but the signals are weak. I have tried blindscan and even deleting and rescanning the transponders but I still can't find the signals that used to work.

Scan them again they are still doing changes

Your signal in the low %50 quality though isn't right.. for an 80cm dish you should be getting much better readings

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Rikkitic

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#2096548 26-Sep-2018 09:20

Thanks for the help. I know something about this but not enough to understand what is really going on.

Your comment about signal quality perplexes me. Even on D1, which is at the focal point of the dish, I never get readings better than around 50% for both signal strength and quality. This is on two different S2 receivers. Also, when adjusting the LNBs, I use a short test cable at the dish so the feed cable down to the TV is not the issue. It does attenuate the signal a little, but not a great deal.

The best quality I have ever achieved is around 60% on D2 at the dish. I also got close to this at one point on IS19 before everything went to hell. Now it is closer to 30%. I will have to fiddle with it some more but I am waiting for stable weather.

I am using the original Sky LNB for Freeview because it has the long throat. The other two are new. I bought them on Aliexpress. They seem to work okay but I don't know how good they are. They are rated at 60 db gain and 0.5 noise factor. I think this is fairly typical.

The dish was installed by Sky many years ago. I assume the orientation is still correct.

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tripper1000

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#2096817 26-Sep-2018 14:10

Are you using multiple LNB's simultaneously? I.E. not actually aiming your dish at IS19? If so, you've giving yourself extra hurdles in the way of receiving a decent signal. When you go for secondary focus points out to the side, the focal points get a bit blurry, and the signal degraded. You really want your weakest satellite (IS19) to be the one at the primary/proper focus point. You may want to go up a dish size to compensate for the weaker secondary focus points.

Below 25% and it becomes unwatchable on my receivers so 30% is pretty low. It will drop out in bad weather and you will start to loose the weaker transponders (possibly that is exactly the problem you are having). Even 50% isn't great. I can get way better than that with a 65cm dish on Freeview, so you may want to look at that.

Rikkitic

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#2096870 26-Sep-2018 14:49

Thanks for the comments. Yes, I am using offset LNBs for the other satellites. The focus is on D1 since the dish was originally installed by Sky. I don't know why our signal is so low. I don't know what it was when we still had Sky because it worked well and I never had any reason to check it. When we had Sky I changed to a dual-throat LNB for Sky and Freeview. A friend added D2 and later I added IS19 myself. All worked well. I only really used IS19 for the news channels Euronews, France TV and RT. I had good reception on all of them. Much later, I started having pixelation issues. It wasn't too bad but it was noticeable. D2 always worked well. I don't know for certain or don't remember what the signal levels were.

At some point the news channels on the IS19 transponder at 12286 stopped working altogether, though I could still receive some other channels. I finally decided to redo the whole thing and bought new LNBs and official mounting brackets to replace the ones I had improvised. I managed to get D2 working correctly again but am still having problems with IS19, which is marginal at best for most channels. The results seem to change. Sometimes I can get some weaker channels (though not the news ones), other times only Arirang and a few others. I seem to have particular trouble receiving the TP at 12286 though it has worked well in the past.

The dish is solidly mounted and I don't see how it could have changed position. I would be reluctant to try to recalibrate it since I don't have a proper satellite finder and am making adjustments while looking at a TV monitor. I am also not prepared to change it to a larger size or install additional dishes. I just want to get it to work as well as it possibly can with the current set-up. I am certain this must be possible because it has worked well in the past. I don't know what would have changed other than the things I have described. Like you, I lose reception when the quality drops below 30% but I have always been able to get more than that. Usually it has been around 50%, which nearly always gives me perfect reception. The best I have ever achieved on any satellite is only a little over 60%.

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tripper1000

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#2096924 26-Sep-2018 15:20

If it used to work fine and now it doesn't that leaves a couple of options:

1) Dish alignment (it does go out with wood warping, metal rusting, plastic shrinking, 10 years of wind buffeting etc).

2) Feeders - coax degradation or splitters/diplexers/connects degrading.

3) Trees, foliage growing and impinging upon the view of the satellite.

4) Degradation of the dish reflective surface- algae, mould, dust, rust and generally corruption build up. Also dish may have warped through age or an impact.

You can generally pick up ex sky dishes for free from friends or the side of the road. Get your hands on one, set it up on your deck and have a play. 1) It's a good way to learn how to align dishes without risk of stuffing up the dish you rely on. 2) if it works better, it helps to narrow down the problem.

You can tweak you dish without a sat-finder. The sat finder is for that - finding satellites. I find that the basic ones aren't much use for precise optimising the alignment - the receiver will generally give a better idea. Get a fine permanent marker and mark the elevation and azimuth. Next, only adjust one axis at a time. Get peak quality left to right, lock it off tight, then get peak quality up to down, lock of off tight and repeat. It means that if you loose the signal you are only looking for the satellite in one plain, which makes it dead easy to require. If you loose the satellite altogether, never try a retune. This will make it next to impossible to acquire the signal without a sat-finder. Plenty of Campervan people do this on a daily basis.