Signal


Charlie
 

I get a slightly different front end (STV6111 per F connector and no matrix) on my setup compared to the TBS cards. Half wonder if that's what kept mine running better in the previous handover issues (the pilot is now set on for BAS, I'm convinced that was 3/4 of the problem...) but really guessing at this point. Single mode is a module option in ddbridge so it is there.

The shared FEC/LDPC would 100% explain what I saw with those particular signal conditions though, and possibly why it only affected HVS-1 and not BAS!

Charlie


Ernst Lobsiger
 

On Thu, Feb 2, 2023 at 03:36 PM, Charlie wrote:

I thought the demodulator/FEC blocks were separate in the STV0910 between the inputs! Perhaps I was wrong here, the cut-down datasheet only has an ambigious block diagram.

First time I've seen that behaviour in any case; anyone using the TBS 6903 or 6908 on Linux witness the same?

Charlie,

how the stv0910 demod chip is fed depends on the setting of the tuner chip stv6120 and matrix switch in front (single cable, two cables).

We probably never had a situation with such big SNR differences between HVS-1 and HVS-2 before (and now these are even H and V).

The LDPC block is shared between the two demodulators. See apsk16 single mode and dual mode on the TBS-6903 specs tab here.

https://www.tbsdtv.com/products/tbs6903-professional-dvb-s2-dual-tuner-pcie-card.html

I remember Konstantin Dimitrov saying: "The only difference between single mode and dual mode is how the LDPC is accessed."
Maybe LDPC is shared 50/50 in dual mode while in single mode each demodulator gets whatever it takes? I faintly remember
(this might be all wrong) that even under single mode I could still tune two transponders. This might lead to a situation where
HVS-2 with low LM disturbs HVS-1 similar to HVS-1 disturbs BAS (that's now 100% speculation though ;-).

The TBS stv091x driver module has a switch for single mode. I have no PC setup with a TBS-6903 now but maybe you can
check in the code how your DD driver handles this single/dual stuff and what it means for peeking and poking registers...

My two cents,
Ernst


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 03/02/2023 13:01, James Brown wrote:
I don’t think I am alone in seeing a decrease of about 0.1 since the ‘recovery’.
 Cheers,
James.
Looking at the graphs, rather than the numbers,my feeling was that C4 (BAS/HVS-1) ended up a little lower in SNR at the end of yesterday compared with the start. Austria. On the other hand C3 (HVS-2/Italy) was unchanged. All this is difficult to judge because of the local and Europe-wide variations during the day.

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

Looks like the snow has got to Poland now, and even a heated dish hasn't been enough protection.

http://www.sp7rb.pl/mrtg/sr1-dual-link-margin.html

If you would like your data to be included there are guidelines here:

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@...
Twitter: @gm8arv


James Brown
 


On 3 Feb 2023, at 12:24, Ernst Lobsiger via groups.io <ernst.lobsiger@...> wrote:

On Fri, Feb 3, 2023 at 03:13 AM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
So one chunk of bad weather causing problems with uplink stations in two different countries. Still surprising how long it took for the problem to be noticed!
David,

Austria has got up to 3 feet of fresh snow
https://www.blick.ch/ausland/mega-schneefall-in-oesterreich-70-menschen-von-schnee-massen-eingeschlossen-id18283095.html
and this weather has been predicted days back ...

Ernst
_._,_._,_


I don’t think I am alone in seeing a decrease of about 0.1 since the ‘recovery’. 

 Cheers,
James. 


Ernst Lobsiger
 

On Fri, Feb 3, 2023 at 03:13 AM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
So one chunk of bad weather causing problems with uplink stations in two different countries. Still surprising how long it took for the problem to be noticed!
David,

Austria has got up to 3 feet of fresh snow
https://www.blick.ch/ausland/mega-schneefall-in-oesterreich-70-menschen-von-schnee-massen-eingeschlossen-id18283095.html
and this weather has been predicted days back ...

Ernst


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 03/02/2023 08:28, Ernst Lobsiger via groups.io wrote:
David,
Lario north of lake Como could have seen snow showers that had crossed Aflenz before.
Fucino near Rome was clear, so this could have been a switch from Lario to Fucino ?
Ernst
Thanks for the locations, Ernst.

Yes, I commented in my daily report that the sudden change of level seemed too quick, and I had wondered about an uplink switch.

So one chunk of bad weather causing problems with uplink stations in two different countries. Still surprising how long it took for the problem to be noticed!

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


Ernst Lobsiger
 

On Thu, Feb 2, 2023 at 09:37 PM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
Uplink sites are Fucino or Lario, in Italy. Weather there?
David,

Lario north of lake Como could have seen snow showers that had crossed Aflenz before.
Fucino near Rome was clear, so this could have been a switch from Lario to Fucino ?

Ernst


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 02/02/2023 20:23, Ernst Lobsiger via groups.io wrote:
Arne,
HVS-2 on C3 is managed by Telespazio. No snow near Rome seen on my images ...
Ernst
Uplink sites are Fucino or Lario, in Italy. Weather there?

The very sudden recovery puzzles me.

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


Charlie
 

Interesting behaviour from my DD card - took out my HVS-1 service when HVS-2 was down enough. Sat just below link threshold - possibly part of the reason if it's still getting through some.

I thought the demodulator/FEC blocks were separate in the STV0910 between the inputs! Perhaps I was wrong here, the cut-down datasheet only has an ambigious block diagram.

First time I've seen that behaviour in any case; anyone using the TBS 6903 or 6908 on Linux witness the same?

Charlie


a_van_belle
 

Thanks Ernst,

So it wasn't snow but it is fixed now.
Let's hope it stays stable.

Greetings,
Arne van Belle


Ernst Lobsiger
 

Hi,

now HVS-2 jumped back. For sure no snow blower!

Ernst


Ernst Lobsiger
 

On Thu, Feb 2, 2023 at 12:08 PM, a_van_belle wrote:
Almost loosing lock on HVS-2 at SNR 9.2 dB.
Uplink dish heating not able to handle the new snow I am guessing.
Arne,

HVS-2 on C3 is managed by Telespazio. No snow near Rome seen on my images ...

Ernst


Douglas Deans
 

On 02/02/2023 19:07, David J Taylor GM8ARV 🏴 🇪🇺 via groups.io wrote:
On 02/02/2023 09:51, Ian Deans via groups.io wrote:
I am seeing a substanial drop on the basic/HVS-1 signal this morning, in
the region of 1.4 /1.5 dB. Hope it is weather related and not the uplink
change over!!!

Regards
Ian.
Looks like C3 is dropping this evening....
https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php#t2
Cheers,
David
===================================================================================================

On checking just now I have no signal on C3.
Even at best it is about 1.0 dB down on C4 and sadly drops the basic signal SNR about 0.3 dB when I use it (on another computer !).
Suspect shielding on dual cable.

Regards,
Douglas.


a_van_belle
 

Almost loosing lock on HVS-2 at SNR 9.2 dB.
Uplink dish heating not able to handle the new snow I am guessing.

Conditions in Aflenz:
https://www.snow-forecast.com/resorts/Aflenz/6day/mid
New snow in Aflenz:  13.0cm on Thu 2nd (after 9 PM)
The snow forecast for Aflenz is: A heavy fall of snow, heaviest during Thu afternoon. Freeze-thaw conditions (max 1°C on Fri morning, min -8°C on Sat night). Winds decreasing (gales from the NW on Fri night, light winds from the NNW by Sun morning).

Maybe a Ski holiday ?
Greetings,
Arne van Belle


a_van_belle
 

T2 on 11263MHz V still dropping in level,  Europe wide !

Isn't this service monitored ?

Greetings,
Arne van Belle


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 02/02/2023 09:51, Ian Deans via groups.io wrote:
I am seeing a substanial drop on the basic/HVS-1 signal this morning, in
the region of 1.4 /1.5 dB. Hope it is weather related and not the uplink
change over!!!
Regards
Ian.
Looks like C3 is dropping this evening....

https://www.satsignal.eu/mrtg/performance_eumetcast-europe_link_margin.php#t2

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


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 02/02/2023 13:14, geojohnt via groups.io wrote:
Ernst,
Yes, interesting thought, perhaps snow blowers borrowed from local ski jumping slopes.
But looking at MSG-4 IR around that time this morning I'm not sure there was (any) snow or at least 'storm clouds' at Aflenz.
And the fact that the SNR jumped 1.5 + dB in an instant would suggest it was something else?
My guess was that the automatic signal levelling had been disabled (perhaps on Feb.01 ?) as the service was supposed to be no longer in use. Or perhaps the dish heater was switched on?

Good to see it back, anyway. Perhaps we'll get the Italian revised uplink again sometime? I hear it is under test.

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


geojohnt@aol.com
 

Ernst,

Yes, interesting thought, perhaps snow blowers borrowed from local ski jumping slopes.

But looking at MSG-4 IR around that time this morning I'm not sure there was (any) snow or at least 'storm clouds' at Aflenz. 
And the fact that the SNR jumped 1.5 + dB in an instant would suggest it was something else?


-----Original Message-----
From: Ernst Lobsiger via groups.io <ernst.lobsiger@...>
To: MSG-1@groups.io
Sent: Thu, 2 Feb 2023 10:27
Subject: Re: [MSG-1] Signal

On Thu, Feb 2, 2023 at 02:04 AM, <geojohnt@...> wrote:
Just gone back up to usual 13.7 dB.
 
John,

if this was snow in Aflenz they switched on the antenna heating at 04:20 UTC and now the took the snow blower :-).

Ernst


Ernst Lobsiger
 

On Thu, Feb 2, 2023 at 02:04 AM, <geojohnt@...> wrote:
Just gone back up to usual 13.7 dB.
 
John,

if this was snow in Aflenz they switched on the antenna heating at 04:20 UTC and now the took the snow blower :-).

Ernst


geojohnt@aol.com
 

Ian,

Just gone back up to usual 13.7 dB.

john


-----Original Message-----
From: geojohnt via groups.io <geojohnt@...>
To: MSG-1@groups.io <MSG-1@groups.io>
Sent: Thu, 2 Feb 2023 9:59
Subject: Re: [MSG-1] Signal

Ian,

Yes, ~ 1.5 dB down here in Sussex at the moment.
Power the usual -18 dBm.

Regards,
John


-----Original Message-----
From: Ian Deans via groups.io <iandeans142@...>
To: MSG-1@groups.io <MSG-1@groups.io>
Sent: Thu, 2 Feb 2023 9:51
Subject: [MSG-1] Signal


I am seeing a substanial drop on the basic/HVS-1 signal this morning, in
the region of 1.4 /1.5 dB. Hope it is weather related and not the uplink
change over!!!

Regards
Ian.