Re: CelesTrak connection (WXTrack)
Von: "David J Taylor via groups.io"
<david-taylor=blueyonder.co.uk@groups.io> Datum: Wed, 27 May 2020 11:11:28 +0100 It's working here, Ulli, Just checked.Exactly sic. Cheers, Ulli
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Re: Signal Drop
Prem
A hot dish can expand or shrink when cooling. It can also distort it's shape very slightly which can affect your signal. There is also your coax cable, mainly copper which will expand and/or shrink to a greater extent than your dish. This can also affect the length of cable which again will slightly affect your signal strength. All coax cables should be cut to the correct length for the frequency that they are being used for. As has already been said, atmospherics plus numerous other spanners in the works without me adding further.
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Prem Holdaway (G0DCP) Phold29@talktalk.net
-----Original Message-----
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Re: CelesTrak connection (WXTrack)
Hi,
In the past days, any attempt to update Keplers with the Updater tool contained in WXTrack is terminated. I get a Socket Error # 10054 - Connection reset by peer error. Bug, feature, ... ? Did I miss an update? Two weeks ago, it still did work. Cheers, Ulli ================================ It's working here, Ulli, Just checked. Is the URL set to: "http://www.celestrak.com/NORAD/elements/" ? Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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CelesTrak connection (WXTrack)
Hi,
In the past days, any attempt to update Keplers with the Updater tool contained in WXTrack is terminated. I get a Socket Error # 10054 - Connection reset by peer error. Bug, feature, ... ? Did I miss an update? Two weeks ago, it still did work. Cheers, Ulli
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Re: Signal Drop
David,
Interesting comments. A problem is, I'm not an RF engineer and I'm just reporting what my SR1 and SatPal meter are showing. What it all means, is another matter :-) Last year(?) Klaus Peter suggested I looked into 'atmospherics' effecting satellite signals which I did and I think I wrote a GEO article on my findings. Of course the sun is very high in the northern hemisphere at the moment so I guess we should expect some 'turbulence?' LNB umbrella is in place and the LNB is shaded from the sun and keeping cool at 09:00 UTC. However, my dark grey 1 m dish gets hot enough to fry an egg - so that will be radiating 'thermal energy.' I wonder if that is a factor? I have a plan to temporarily deal with the dish warming - watch this space. SR1 TP 1 SNR down from 13.0 dB last night to 12.6/5 dB at the moment with cool LNB. Regards, John =================================== John, First thoughts are that a hot dish means the LNB is looking at a warm source rather than the cold sky! Warm means more noise, poorer SNR, lower link margin. However, it depends on what the dish "looks" like at 11 GHz. Perhaps that grey surface is fully reflective at that frequency, so the LNB is looking at a cold sky. I don't think it will be a perfect reflector, so some dish temperature rise will result in SNR loss. The other effect is that the LNB will have at least /some/ "seeing" outside the disk of the dish, so a warm background is not desirable. Moving the LNB nearer the dish will result in "seeing" less outside the dish, but having a smaller capture area and hence get a smaller amount of signal. Keep monitoring! Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
geojohnt@...
David,
Interesting comments.
A problem is, I'm not an RF engineer and I'm just reporting what my SR1 and SatPal meter are showing.
What it all means, is another matter :-)
Last year(?) Klaus Peter suggested I looked into 'atmospherics' effecting satellite signals which I did and I think I wrote a GEO article on my findings.
Of course the sun is very high in the northern hemisphere at the moment so I guess we should expect some 'turbulence?'
LNB umbrella is in place and the LNB is shaded from the sun and keeping cool at 09:00 UTC.
However, my dark grey 1 m dish gets hot enough to fry an egg - so that will be radiating 'thermal energy.'
I wonder if that is a factor? I have a plan to temporarily deal with the dish warming - watch this space. SR1 TP 1 SNR down from 13.0 dB last night to 12.6/5 dB at the moment with cool LNB.
Regards,
John
+++++++++++++++++++++
Most interesting comparisons, John. At lower signal levels I suspect there is a degree of confusion in that we talk of: signal / noise but what we are actually measuring is most likely (signal + noise) / noise so a change of signal at higher signal levels will result in a greater change in the measurement than at lower levels, where the value will tend to zero 0dB (and not go negative!). Noise isn't measured separately. So was the apparent level of the TV signal higher? The graphs now clearly show that there was a dip seen by many stations between~14:30 and 15:10 UTC. https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php which may also have confused spot time level comparisons. Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@... Twitter: @gm8arv ++++++++++++++++++++++++++
-----Original Message-----
From: David J Taylor via groups.io <david-taylor@...> To: MSG-1@groups.io Sent: Wed, 27 May 2020 7:01 Subject: Re: [MSG-1] Signal Drop Ian and All,
As I thought (hoped) my TP 1 SNR was back up to 12.9 - 13.0 db by 17:00 UTC today. It is currently 13.0 - 12.9 dB at 20:30 UTC. Yes, the LNB does get baked in the sun at this time of year so I'm going to try to fashion an umbrella before dawn. One thing I found was that the TV channels on Eurelsat 10 A and Eutelsat 9 did not show such a drastic change in SNR level. In fact it was perhaps 0.3 dB at the most - same dish same LNB. My EUMETCast TP 1 SNR has an overall change in level of 0.8 dB. I suspect comparing TP 1 with a TV channel on 10-A is irrelevant anyway? Regards, John. =====================================
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Re: Signal Drop
Ian and All,
As I thought (hoped) my TP 1 SNR was back up to 12.9 - 13.0 db by 17:00 UTC today. It is currently 13.0 - 12.9 dB at 20:30 UTC. Yes, the LNB does get baked in the sun at this time of year so I'm going to try to fashion an umbrella before dawn. One thing I found was that the TV channels on Eurelsat 10 A and Eutelsat 9 did not show such a drastic change in SNR level. In fact it was perhaps 0.3 dB at the most - same dish same LNB. My EUMETCast TP 1 SNR has an overall change in level of 0.8 dB. I suspect comparing TP 1 with a TV channel on 10-A is irrelevant anyway? Regards, John. ===================================== Most interesting comparisons, John. At lower signal levels I suspect there is a degree of confusion in that we talk of: signal / noise but what we are actually measuring is most likely (signal + noise) / noise so a change of signal at higher signal levels will result in a greater change in the measurement than at lower levels, where the value will tend to zero 0dB (and not go negative!). Noise isn't measured separately. So was the apparent level of the TV signal higher? The graphs now clearly show that there was a dip seen by many stations between~14:30 and 15:10 UTC. https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php which may also have confused spot time level comparisons. Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
I've mentioned this to EUMETSAT and pointed them towards the group topic. I'm sure that direct reports would be valued.
Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
geojohnt@...
Ian and All,
As I thought (hoped) my TP 1 SNR was back up to 12.9 - 13.0 db by 17:00 UTC today.
It is currently 13.0 - 12.9 dB at 20:30 UTC.
Yes, the LNB does get baked in the sun at this time of year so I'm going to try to fashion an umbrella before dawn.
One thing I found was that the TV channels on Eurelsat 10 A and Eutelsat 9 did not show such a drastic change in SNR level.
In fact it was perhaps 0.3 dB at the most - same dish same LNB.
My EUMETCast TP 1 SNR has an overall change in level of 0.8 dB.
I suspect comparing TP 1 with a TV channel on 10-A is irrelevant anyway?
Regards,
John.
-----Original Message-----
From: geojohnt via groups.io <geojohnt@...> To: MSG-1@groups.io <MSG-1@groups.io> Sent: Tue, 26 May 2020 12:58 Subject: Re: [MSG-1] Signal Drop Ian,
I finally got around to putting my 1 m dish into its new - slightly more away from the fir tree - location from the temporary one its been in for a couple of months, late afternoon yesterday.
I don't think it is 'fully aligned' but I was pleased with the results on TP 1 - 12.8 - 12.9 dB SNR with an SR1 at that time and in the evening.
However, this morning 07:30 UTC my SNR was 12.3 - 12.4 dB later dropping to 12.2 - 12.3 dB.
Currently at 11:15 UTC my SNR is 12.5 - 12.6 dB - but it is stepping a bit by 0.3 dB at times.
I'll be monitoring during the day to see if it has gone up again to yesterday's levels at 17:00.
Also at the same time I'm monitoring Eutelsat 10-A on my SatPal spectrum analyser but it does not indicate SNR for EUMETCast owing to the VCM format.
But I do get get full parameters for 10A's TV channels as a guide to any of their changing levels.
I'm also monitoring Eutelsat 9's TV channel parameters/level over time - which I receive on the same dish, with the SatPal meter.
Given the large SNR vertical scale on EUMETCast Europe logging on David's website - 0.0 to 18.0 dB, even that shows 'small variations' of SNR given the large 3 dB scale step between segment SNR levels.
Dare I say that it would be interesting to have a scale a 'very' expanded scale to see these ~ 0.5 db variation in clear sky SNR.
The diurnal SNR variation - that I've always experienced, appears not to be seen by some users???
Regards,
John
-----Original Message-----
From: Ian Deans via groups.io <iandeans142@...> To: MSG-1@groups.io Sent: Tue, 26 May 2020 11:12 Subject: [MSG-1] Signal Drop I am seeing another drop in the signal over the last 48 hours or so, in
the region of 0.2 to 0.3 SNR. Hopefully just a temporary drop.
Regards
Ian.
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Re: Signal Drop
David,
To give some more documentation, my SNR over the day is comparable with the signal of the station in Huizen-NL I have a slight smaller dish 125 cm so my SNR is on average over the day 0,2 dB lower than the station in Huizen. I see that the Huizen signal level is also lower than that it was before. So for me there is enough link margin left and I have very few packet losses and that is what counts. Greetings Herman ========================================== Thanks, Herman. Yes, the drop at Huizen is clear, and yet not at all stations. Why? Atmospheric conditions? A small change at the satellite? I think not at the uplink station, though. Adding MRTG to record the link margin and whatever other data you might find useful is something you might like to look at. Oh, that there was another 2 or 3 dB from the satellite! Yes, I know that's double the power..... Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
From: Ian Deans via groups.io
[] I am still seeing a drop in signal which I am checking regularily. Dish allignment checked and is OK. I take your point re no documented evidence, so will avoid any further reports in the future re signal levels. Ian. ================================ Ian, The intention was to encourage you to add the programs allowing you to plot the data automatically, saving you time an effort and providing a long-term record for a year or more. It makes it easier to compare your data with others. All the software is free. Please do continue to provide reports as the level (well, SNR) is a very critical system parameter for EUMETCast especially in our part of the world! Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
David,
heating up the LNB adds thermal noise to the signal. This causes a drop of the link margin. Cheeers Thorsten ================================= Yes, it could be just that. Thanks, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
Herman Vijlbrief
David,
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To give some more documentation, my SNR over the day is comparable with the signal of the station in Huizen-NL I have a slight smaller dish 125 cm so my SNR is on average over the day 0,2 dB lower than the station in Huizen. I see that the Huizen signal level is also lower than that it was before. So for me there is enough link margin left and I have very few packet losses and that is what counts. Greetings Herman
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Re: Signal Drop
Ian Deans
On 26/05/2020 15:01, David J Taylor via groups.io wrote:
I am seeing another drop in the signal over the last 48 hours or so, in=============================================================================== I am still seeing a drop in signal which I am checking regularily. Dish allignment checked and is OK. I take your point re no documented evidence, so will avoid any further reports in the future re signal levels. Ian.
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Re: Signal Drop
David,
toggle quoted messageShow quoted text
heating up the LNB adds thermal noise to the signal. This causes a drop of the link margin. Cheeers Thorsten
On Tue, May 26, 2020 at 04:03 PM, David J Taylor wrote:
Ian, Herman,
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Re: Signal Drop
I am seeing another drop in the signal over the last 48 hours or so, in
the region of 0.2 to 0.3 SNR. Hopefully just a temporary drop. Regards Ian. ============================== Ian, Herman, I see no evidence for such a drop over the last 2 days: https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php?period=month I find it difficult to accept reports with little documented backing. However, what I have seen recently is a drop in link margin when the sun illuminates the LNB early in the morning (as it happens in my particular configuration). I'm unsure what the cause is - perhaps the cover is becoming warm and that's heating some dust or bird deposit on the cover. I've looked from ground level with binoculars but there's nothing obvious. Perhaps the LNB (or at least its cover) is due for replacement. £10 for the part and £100 labour! You can see this on yesterday's plot at ~06:30 UTC until ~09:45, and something on today's plot with a rise around 13:20. https://www.satsignal.eu/mrtg/sr1-dual-link-margin.html Monitoring is relatively easy to set up with either Ayecka SR1 or TBS/BDADataEx receivers. https://www.satsignal.eu/wxsat/dvb-s2/sr1-mrtg.html Cheers, David -- SatSignal Software - Quality software for you Web: https://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv
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Re: Signal Drop
geojohnt@...
Ian,
I finally got around to putting my 1 m dish into its new - slightly more away from the fir tree - location from the temporary one its been in for a couple of months, late afternoon yesterday.
I don't think it is 'fully aligned' but I was pleased with the results on TP 1 - 12.8 - 12.9 dB SNR with an SR1 at that time and in the evening.
However, this morning 07:30 UTC my SNR was 12.3 - 12.4 dB later dropping to 12.2 - 12.3 dB.
Currently at 11:15 UTC my SNR is 12.5 - 12.6 dB - but it is stepping a bit by 0.3 dB at times.
I'll be monitoring during the day to see if it has gone up again to yesterday's levels at 17:00.
Also at the same time I'm monitoring Eutelsat 10-A on my SatPal spectrum analyser but it does not indicate SNR for EUMETCast owing to the VCM format.
But I do get get full parameters for 10A's TV channels as a guide to any of their changing levels.
I'm also monitoring Eutelsat 9's TV channel parameters/level over time - which I receive on the same dish, with the SatPal meter.
Given the large SNR vertical scale on EUMETCast Europe logging on David's website - 0.0 to 18.0 dB, even that shows 'small variations' of SNR given the large 3 dB scale step between segment SNR levels.
Dare I say that it would be interesting to have a scale a 'very' expanded scale to see these ~ 0.5 db variation in clear sky SNR.
The diurnal SNR variation - that I've always experienced, appears not to be seen by some users???
Regards,
John
-----Original Message-----
From: Ian Deans via groups.io <iandeans142@...> To: MSG-1@groups.io Sent: Tue, 26 May 2020 11:12 Subject: [MSG-1] Signal Drop I am seeing another drop in the signal over the last 48 hours or so, in
the region of 0.2 to 0.3 SNR. Hopefully just a temporary drop.
Regards
Ian.
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Re: Signal Drop
Herman Vijlbrief
Ian,
toggle quoted messageShow quoted text
Same here in Hoofddorp The Netherlands. Regards Herman Op 26-5-2020 om 12:12 schreef Ian Deans via groups.io:
I am seeing another drop in the signal over the last 48 hours or so, in the region of 0.2 to 0.3 SNR. Hopefully just a temporary drop.
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Signal Drop
Ian Deans
I am seeing another drop in the signal over the last 48 hours or so, in the region of 0.2 to 0.3 SNR. Hopefully just a temporary drop.
Regards Ian.
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Re: Pytroll/SatPy for EUMETCast
Graham Woolf
Hi Ernst
OK thanks that gives me something to look at My raw data files are on a networked NAS drive which is always connected. I only run three scripts in succession The temp dir might be an issue although all my batch files have a timeout 20 at the end which i thought meant wait for 20 seconds before running the next script Maybe thats not working how I expect it to Kind Regards Graham
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