Topics

Signal

Ian Deans
 

I am currently seeing a big drop in the basic signal at the moment in what is sunny conditions. This year the signal levels have been disappointing with a general drop of about 0.4/0.5 SNR and at the moment it is double that.

My dish and LNB have been checked and are fine.

Regards
Ian.

geojohnt@...
 

Hello Ian,

Yes, same here (SW London) - way down on what it should be.
and again clear sunny skies and 'hot!'

I thought it might have been some tall flowers growing in front of my dish, which keep growing - but obviously not.

Regards,
John.

++++++++++++++++++++++++++


In a message dated 13/09/2019 14:43:01 GMT Standard Time, iandeans142@... writes:

I am currently seeing a big drop in the basic signal at the moment in
what is sunny conditions. This year the signal levels have been
disappointing with a general drop of about 0.4/0.5 SNR and at the moment
it is double that.

My dish and LNB have been checked and are fine.

martin Handl
 

from czech any problem booth transponder work

Hello Ian,

Yes, same here (SW London) - way down on what it should be.
and again clear sunny skies and 'hot!'

I thought it might have been some tall flowers growing in front of my dish, which keep growing - but obviously not.

Regards,
John.

++++++++++++++++++++++++++


In a message dated 13/09/2019 14:43:01 GMT Standard Time, iandeans142@... writes:

I am currently seeing a big drop in the basic signal at the moment in
what is sunny conditions. This year the signal levels have been
disappointing with a general drop of about 0.4/0.5 SNR and at the moment
it is double that.

My dish and LNB have been checked and are fine.

Ian Deans
 

On 13/09/2019 16:09, geojohnt via Groups.Io wrote:
Hello Ian,
Yes, same here (SW London) - way down on what it should be.
and again clear sunny skies and 'hot!'
I thought it might have been some tall flowers growing in front of my dish, which keep growing - but obviously not.
Regards,
John.
=======================================================

Thanks for the confirmation John. The signal has been down for a few hours now. My HVS-2 signal is actually 0.2 SNR higher at the moment than my basic signal. It is usually about 0.4 SNR lower.

Regards
Ian.

Hartmut Schulla
 

Yeah! Same here:

day

Drop at 11:30 UTC from 14.9db to 13.8db

Regards

Hartmut

 

Von: MSG-1@groups.io [mailto:MSG-1@groups.io] Im Auftrag von geojohnt via Groups.Io
Gesendet: Freitag, 13. September 2019 17:09
An: MSG-1@groups.io
Betreff: Re: [MSG-1] Signal

 

Hello Ian,

 

Yes, same here (SW London) - way down on what it should be.

and again clear sunny skies and 'hot!'

 

I thought it might have been some tall flowers growing in front of my dish, which keep growing - but obviously not.

 

Regards,

John.

 

++++++++++++++++++++++++++

 

 

In a message dated 13/09/2019 14:43:01 GMT Standard Time, iandeans142@... writes:

 

I am currently seeing a big drop in the basic signal at the moment in

what is sunny conditions. This year the signal levels have been

disappointing with a general drop of about 0.4/0.5 SNR and at the moment

it is double that.

 

My dish and LNB have been checked and are fine.

Hartmut Schulla
 

Dual Link Margin Drop:

day

Regards

Hartmut

 

David J Taylor
 

I am currently seeing a big drop in the basic signal at the moment in
what is sunny conditions. This year the signal levels have been
disappointing with a general drop of about 0.4/0.5 SNR and at the moment
it is double that.

My dish and LNB have been checked and are fine.

Regards
Ian.
====================================

It seems to be the same across Europe:

https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php

Best to report this to EUMETSAT.

I see that the H polarisation (cyan) has dropped compared to the vertical (red) between September 02 and today, and that there is a new lower level and narrower bandwidth signal on the H polarisation around 11320 MHz. Vertical polarisation has gained a signal on ~11425 MHz. I am not saying these changes have caused the drop, but they may be related.

These plots with a TBS5925 and CrazyCat's CrazyScan program fed from a spare feed on the 4-output LNB. Ignore the apparent tilt across the passband, and the dB scale.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

James Brown
 

On 13/09/2019 17:13, David J Taylor via Groups.Io wrote:
I am currently seeing a big drop in the basic signal at the moment in
what is sunny conditions. This year the signal levels have been
disappointing with a general drop of about 0.4/0.5 SNR and at the moment
it is double that.

My dish and LNB have been checked and are fine.

Regards
Ian.
====================================

It seems to be the same across Europe:

 https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php

Best to report this to EUMETSAT.

I see that the H polarisation (cyan) has dropped compared to the vertical (red) between September 02 and today, and that there is a new lower level and narrower bandwidth signal on the H polarisation around 11320 MHz. Vertical polarisation has gained a signal on ~11425 MHz.  I am not saying these changes have caused the drop, but they may be related.

These plots with a TBS5925 and CrazyCat's CrazyScan program fed from a spare feed on the 4-output LNB.  Ignore the apparent tilt across the passband, and the dB scale.

Cheers,
David
This is not good news! IIRC we have been here before and has only resulted in LNB and dish deficiencies being identified, rather than adjacent transponder issues. I do hope not, but am not holding my breath!

James

George Sz
 

I can confirm the signal drop as well.

David J Taylor
 

From: George Sz

I can confirm the signal drop as well.
=======================

George,

Please report this to EUMETSAT.

Thanks,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

geojohnt@...
 

James,

Well, many users graphs show a distinct step down in SNR.
And indeed we have been here before - 3 times, if I recall correctly?
And although 'something' was tweaked 'their end' on every occasion, I never got back to my original SNR levels.

A couple of years ago I was getting 14.3 dB SNR during the 'diurnal max.' period with a 1 m dish and Inverto Black Ultra LNB and an SR1.
Diurnal max now is - was - around 13.4/5 dB
I'm not on 'diurnal max' at this time today and my BS SNR is currently 12.6 - 12.8 dB.

OK, I still have quite a high link margin on BS so no problem.
But I don't think this is a dish/LNB deficiency but a transmitted power 'reduction.'

There hasn't been any 'bad weather' over the uplink station yesterday and certainly not today.

?????

Regards,
John.

++++++++++++++++++++++++++++

In a message dated 13/09/2019 19:00:21 GMT Standard Time, satellite@... writes:


This is not good news! IIRC we have been here before and has only
resulted in LNB and dish deficiencies being identified, rather than
adjacent transponder issues. I do hope not, but am not holding my breath!

James

geojohnt@...
 

All,

For what it's worth, here are my received Eutelsat 10 A signal comparisons earlier as shown by the Inverto SatPal meter.

They are EUMETCast on 11.263 GHz H.
Tricolor IPTV on 11.263 GHz V.
A 'Eutelsat channel' (DVB-S) MPEG 4 on 11.346 GHz H, which might give me an ongoing steady signal level marker?

My SR1 was showing a SNR at the time of 12.8/9 dB.
The Power reading was -25 dBm - as always.

The SatPal meter will not demodulate VCM/ACM data signals and so just gives a signal level, not SNR, link margin and mosaic - as it does with 'TV signals.'

Regards,
John.





James Brown
 

I was reiterating the ‘reason’ or excuse, depending on your viewpoint!
It will probably turn out to be interference rather than loss of power, though I did wonder  if it was a satellite station keeping manoeuvre until I saw David’s graphs.

Cheers,
James

On 14 Sep 2019, at 10:49, geojohnt via Groups.Io <geojohnt@...> wrote:

James,

Well, many users graphs show a distinct step down in SNR.
And indeed we have been here before - 3 times, if I recall correctly?
And although 'something' was tweaked 'their end' on every occasion, I never got back to my original SNR levels.

A couple of years ago I was getting 14.3 dB SNR during the 'diurnal max.' period with a 1 m dish and Inverto Black Ultra LNB and an SR1.
Diurnal max now is - was - around 13.4/5 dB
I'm not on 'diurnal max' at this time today and my BS SNR is currently 12.6 - 12.8 dB.

OK, I still have quite a high link margin on BS so no problem.
But I don't think this is a dish/LNB deficiency but a transmitted power 'reduction.'

There hasn't been any 'bad weather' over the uplink station yesterday and certainly not today.

?????

Regards,
John.

++++++++++++++++++++++++++++

In a message dated 13/09/2019 19:00:21 GMT Standard Time, satellite@... writes:


This is not good news! IIRC we have been here before and has only
resulted in LNB and dish deficiencies being identified, rather than
adjacent transponder issues. I do hope not, but am not holding my breath!

James

David J Taylor
 

Response from EUMETSAT:

"Regarding your enquiry, please be informed that this change has been decided by the satellite operator."

Words fail me.... (polite words, anyway).

David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

James Brown
 

Extraordinary! I can only guess that the overall footprint parameters has not decreased enough to concern Eumetsat.

Very disappointing.
James

On 16 Sep 2019, at 11:33, David J Taylor via Groups.Io <gm8arv=yahoo.co.uk@groups.io> wrote:

Response from EUMETSAT:

"Regarding your enquiry, please be informed that this change has been decided by the satellite operator."

Words fail me.... (polite words, anyway).

David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Ian Deans
 

On 16/09/2019 11:33, David J Taylor via Groups.Io wrote:
Response from EUMETSAT:
 "Regarding your enquiry, please be informed that this change has been decided by the satellite operator."
Words fail me.... (polite words, anyway).
David
===============================================================
I find it hard to believe that Eumetsat have no say in this, although it may be that the professionals are still able to get a good signal.

Over a year ago I increased my dish size from 1 metre to 1.1 metre and was able to increase my signal from an average of about 12.4 SNR to 13.3 SNR. With a general drop over 6 months or so and this sudden drop I am back at 12.3 SNR and to be honest I would get a slightly better basic service signal on the HVS-2 transponder.

All very disappointing.

Regards
Ian.

geojohnt@...
 

All,

>   "Regarding your enquiry, please be informed that this change has been 
> decided by the satellite operator."

> Words fail me.... (polite words, anyway).

>Extraordinary! I can only guess that the overall footprint parameters has not decreased enough to >concern Eumetsat. 
>Very disappointing.

>I find it hard to believe that Eumetsat have no say in this, although it 
>may be that the professionals are still able to get a good signal.
>All very disappointing.

Well, we (I) am seeing at least a 0.5 dB drop in SNR on BS - I haven't checked HVS-1 yet, though it should be the same.

EUMETSAT presumably pays for a certain 'transponder signal output?'
In which case they are now owed a reduction in the cost of the hire of the transponder?

It will be interesting to see if they reflect this drop in signal power in their EUMETCast Service Availability Analysis document?


If only we could get them to - they would - switch back to Eutelsat 9 with it's 3 dB higher power output.
Minimal antenna adjustment for all - to boot!

10 A launched 03-04-2009 max power contour 48 dBW.
9 B launched 30-01-2016 max power contour 51 dBW

Regards,
John.


Thorsten Miglus
 

John,

this is not a drop in output power but a raise of noise. This gives us a lower signal / noise ratio.
The source of additional noise may be another transponder.

Cheers,
Thorsten


On Mon, Sep 16, 2019 at 02:07 PM, <geojohnt@...> wrote:
Well, we (I) am seeing at least a 0.5 dB drop in SNR on BS - I haven't checked HVS-1 yet, though it should be the same.
 
EUMETSAT presumably pays for a certain 'transponder signal output?'
In which case they are now owed a reduction in the cost of the hire of the transponder?

It will be interesting to see if they reflect this drop in signal power in their EUMETCast Service Availability Analysis document?
 
 
If only we could get them to - they would - switch back to Eutelsat 9 with it's 3 dB higher power output.
Minimal antenna adjustment for all - to boot!
 
10 A launched 03-04-2009 max power contour 48 dBW.
9 B launched 30-01-2016 max power contour 51 dBW
 
Regards,
John.
 

geojohnt@...
 

Thorsten,

OK, thanks for that.

Now, what might that be?
Are you suggesting another transponder on 10-A is/has perhaps started putting out 'spurious?'

There is already a V polarised channel on (the same frequency as EUMETCast) 11.263 GHz - Tricolor IP-TV but it's 'power' spectrum appears much lower that EUMETCast on my meter.

Eutelsat 9 B's Ku-band transmissions start at 11.722 GHz V - so that isn't a problem(?) even though they can be well received with a dish aligned on 10 east.

Eutelsat 9-A is a Ka-band satellite channels starting at 19.722 GHz L.
I see all data channels use DVB-S2 ACM.

Co-channel interference from Eutelsat 13 east or Eutelsat 7 east is hardly likely with the size of dish we are using?

Though, having said that, the reason given by EUMETSAT (and I must dig out the email to check) for an earlier step and period of reduced SNR was blamed on an adjacent satellite, I seem to recall.

Regards,
John.

++++++++++++++++++++

In a message dated 16/09/2019 16:02:43 GMT Standard Time, thorsten.miglus@... writes:

this is not a drop in output power but a raise of noise. This gives us a lower signal / noise ratio.
The source of additional noise may be another transponder.

David J Taylor
 

John,

this is not a drop in output power but a raise of noise. This gives us a lower signal / noise ratio.
The source of additional noise may be another transponder.

Cheers,
Thorsten
==================================

Thorsten,

I'm inclined to agree with you, and if you haven't already reported this to EUMETSAT please do so.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv