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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