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HVS-1 link margin in negative territory for around 42 minutes.

geojohnt@...
 

Dear All,

Sorry for the late report - just had to watch the Supreme Court news coverage.

I lost my HVS-1 channel this morning from 07:41 to 08:22 GMT owing to very low SNR caused by torrential rain at times and/or thick cloud from the storm crossing the UK at the moment.

At one point my SNR was down to 7.8 dB giving a link margin of -1.5 dB on HVS-1.

I've only been running HVS-1 since Feb/March and have not experienced this long an outage before.
Having said that, we haven't had that much rain down here in SW London this year - and not this heavy.

At times, as usual, it was not the rain causing the lowered SNR but obviously the cloud above.

My LNB rain shield kept the LNB face free of rain drops - the SNR would have been ~ 0.8 dB (even) lower without it.
1 m dish, Inverto Black Ultra LNB and SR1 receiver.

When my SNR was at its lowest my satellite Power reading was -27 dBm.
It remained at this level for quite some time.
The usual steady reading is -25 dBm.

The HVS-1 icon went red around 07:41 at SNR 9.0 dB Power -27 dBm.
I rebooted it and it sat there yellow till 08:23 when it 'connected' requiring the link margin above +1 dB, if I recall correctly.

However, the latest (3rd?) step drop in SNR has not helped matters.

This doesn't look good if we are going to get more of these 'storm events?'

SNR now at 11:25 GMT with some cloud but no rain is 12.8 dB around the (new) usual (lower) level now.

Regards,
John Tellick



geojohnt@...
 

All,

Oh this is ridiculous!

I've just lost both HVS-1 - and BS this time.

A large towering cloud went over and although no rain my EUMETCast SR1 Es/No dropped to 3.1 dB at
13:34:45 with Power dropping from (the usual) -25 dBm to -30 dBm.
The outage started around 13:24 with firstly the loss of HVS-1 and then BS - red tc icons.

This time I monitored Eutelsat 10's 'eutelsat channel' 11.346 GHz H which is (actually) DVB-S MPEG-4 27500 3/4 on another of the LNB's quad outputs.
It's C/N dropped from the usual 15 dB to 4.8 dB and lost lock briefly at this level on the SatPal meter.
The meter appears to be very sensitive and C/N was varying considerably up and down like a yo-yo during this period.

And my location is well within the highest power contour of Eutelsat 10 A!

Regards,
John.


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


In a message dated 24/09/2019 12:25:50 GMT Standard Time, geojohnt@... writes:

Dear All,

Sorry for the late report - just had to watch the Supreme Court news coverage.

I lost my HVS-1 channel this morning from 07:41 to 08:22 GMT owing to very low SNR caused by torrential rain at times and/or thick cloud from the storm crossing the UK at the moment.

At one point my SNR was down to 7.8 dB giving a link margin of -1.5 dB on HVS-1.

I've only been running HVS-1 since Feb/March and have not experienced this long an outage before.
Having said that, we haven't had that much rain down here in SW London this year - and not this heavy.

At times, as usual, it was not the rain causing the lowered SNR but obviously the cloud above.

My LNB rain shield kept the LNB face free of rain drops - the SNR would have been ~ 0.8 dB (even) lower without it.
1 m dish, Inverto Black Ultra LNB and SR1 receiver.

When my SNR was at its lowest my satellite Power reading was -27 dBm.
It remained at this level for quite some time.
The usual steady reading is -25 dBm.

The HVS-1 icon went red around 07:41 at SNR 9.0 dB Power -27 dBm.
I rebooted it and it sat there yellow till 08:23 when it 'connected' requiring the link margin above +1 dB, if I recall correctly.

However, the latest (3rd?) step drop in SNR has not helped matters.

This doesn't look good if we are going to get more of these 'storm events?'

SNR now at 11:25 GMT with some cloud but no rain is 12.8 dB around the (new) usual (lower) level now.

Regards,
John Tellick



Ian Deans
 

On 24/09/2019 15:10, geojohnt via Groups.Io wrote:
All,
Oh this is ridiculous!
I've just lost both HVS-1 - and BS this time.
A large towering cloud went over and although no rain my EUMETCast SR1 Es/No dropped to 3.1 dB at
13:34:45 with Power dropping from (the usual) -25 dBm to -30 dBm.
The outage started around 13:24 with firstly the loss of HVS-1 and then BS - red tc icons.
This time I monitored Eutelsat 10's 'eutelsat channel' 11.346 GHz H which is (actually) DVB-*S* MPEG-4 27500 3/4 on another of the LNB's quad outputs.
It's C/N dropped from the usual 15 dB to 4.8 dB and lost lock briefly at this level on the SatPal meter.
The meter appears to be very sensitive and C/N was varying considerably up and down like a yo-yo during this period.
And my location is well within the highest power contour of Eutelsat 10 A!
Regards,
John.
==========================================================================

There is no doubt about it John that the drop of 0.5/0.6 SNR in the basic/HVS-1 signal will result in more incidences of lost HVS-1 data.

If a separate receiver is used for basic only, losses due to signal should be few as it needs to drop to below 6 SNR before losses occur.

For me up here north of Dundee and out the main footprint the drop in the TP-1 signal is very unfortunate and I still wonder why it was necessary.

My TP-2 signal is now marginally higher than the TP-1 signal, which is to be expected as Eumetsat had previously indicated that the TP-2 signal would be approx. 0.4 SNR lower than TP-1.

Regards
Ian.

geojohnt@...
 

Ian,

I've never lost BS before - though this year I have had some error messages in the 'new' updated TC which I started using several months ago.

I'm on the edge of a large cloud again at the moment and SNR is dropping.
Fortunately it is the back end of a big! cloud travelling east to the north of me showing up well on Channel 12 Hi-Res 15:30.

Whatever happened to the days early last year where my basic SNR was 13.9 - 14.3 dB clear sky?

Now it is 12.4/5 - 12.9/13.00 dB.

Er, bigger dish?
Cut down the neighbours fir tree?

Regards,
John.

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


In a message dated 24/09/2019 16:08:27 GMT Standard Time, iandeans142@... writes:

There is no doubt about it John that the drop of 0.5/0.6 SNR in the
basic/HVS-1 signal will result in more incidences of lost HVS-1 data.

If a separate receiver is used for basic only, losses due to signal
should be few as it needs to drop to below 6 SNR before losses occur.

Douglas Deans
 

John in truth none of this should be needed.
Over the years I have spent many hours fine tuning my dish for maximum reception, invested in a 1.0 metre dish to help with the poor Scottish signal (dubiously legal up here !) and due to those endeavours found that sometimes on a good clear morning I could just see an SNR into the 13s. And now over the past year one issue after another has slowly eroded signal and despite much fine tuning I can now never see an SNR starting with anything higher than 11.  
The Eumetcast service is an amazing service for amateurs and I have nothing but admiration for Eumetsat allowing amateurs to receive it, but not withstanding that it seems to me that something is amiss with the management of this 10 year old satellite. Perhaps TV and money rules. 

I for one am now thinking of finding an alternative way of getting the data.

Regards,
Douglas.

PS. apologies if my mail layout is poor but BT pop3 is again down so composing on the server which I hate !
-------------------------------------------------------------------------------------------------------------------------


On Tuesday, 24 September 2019, 16:38:16 BST, geojohnt via Groups.Io <geojohnt@...> wrote:


Ian,

I've never lost BS before - though this year I have had some error messages in the 'new' updated TC which I started using several months ago.

I'm on the edge of a large cloud again at the moment and SNR is dropping.
Fortunately it is the back end of a big! cloud travelling east to the north of me showing up well on Channel 12 Hi-Res 15:30.

Whatever happened to the days early last year where my basic SNR was 13.9 - 14.3 dB clear sky?

Now it is 12.4/5 - 12.9/13.00 dB.

Er, bigger dish?
Cut down the neighbours fir tree?

Regards,
John.

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



_._,_._,_

David J Taylor
 

Ian,

I've never lost BS before - though this year I have had some error messages in the 'new' updated TC which I started using several months ago.

I'm on the edge of a large cloud again at the moment and SNR is dropping.
Fortunately it is the back end of a big! cloud travelling east to the north of me showing up well on Channel 12 Hi-Res 15:30.

Whatever happened to the days early last year where my basic SNR was 13.9 - 14.3 dB clear sky?

Now it is 12.4/5 - 12.9/13.00 dB.

Er, bigger dish?
Cut down the neighbours fir tree?

Regards,
John.
==============================================

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David
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