BBC restricted?

[Griga]

Dows anybody know if the BBC transponder 10773 H on Astra 28° East is temporarily broadcasting with a reduced signal strength?

 

Recently I got a new dish and adjusted it. BBC signal quality was fine (western part of Germany). But then it got very low - I could still watch BBC, but the slightest rain killed it. Next day it was ok. Yesterday it was very low. Now it's up again...

 

First I assumed that something is wrong with my new dish. But now I suspect that they purposely reduce the signal strength on days with World Cup transmissions, in order to limit reception to a smaller area.

 

Today ITV does the job (with normal signal strength, as far as I can see), and as I said, BBC 1 is fine again... maybe some licence clash with other broadcasters in Europe? Did somebody hear or read something about it?

[Zyknyp]

Not that I'm aware of.

[Griga]

It's really strange. It doesn't depend on the weather - I had the low level on a sunny day, and today it's cloudy and I get full strength. Other 28° East transponders are not affected. However, when it it happens next time I'll additionally check BBC 1 Scotland on 10802 H.

[jf2020]

I had the low level on a sunny day, and today it's cloudy and  I get full strength.

<{POST_SNAPBACK}>

 

This is a total guess but what may happen is that the shape of the dish is modified when it gets hot (especially if the dish has a dark color) inducing a disalignment and a reduced signal. The Mutytenne can be more sensitive to that as it has a complex shape to allow it to have more than one focus.

[Griga]

what may happen is that the shape of the dish is modified when it gets hot

Quite unlikely. The signal quality varies slightly when the sun is shining and the dish and LNB get warm, but not that much. When it is ok, my SkyStar2 reports a value above 40% (green), when it is low, only 26% (red). Other Astra 28° East transponders are not affected, e.g. ITV on 10832 H still remains above 40%. It's just that frequency.

 

Well, I'll keep an eye on that mystery...

[Griga]

I've found something in the web - not up-to-date, but it may point in the right direction. A small dish usually receives more interference from adjacent satellites than a large one, since the focus is not so sharp.

 

12. Why is the BBC transponder at 10.773GHz horizontal affected worse than any other?

 

Astra 1D is currently 'parked' at 24.2 degrees, and is radiating a PAL testcard on 10.773GHz horizontal (and nothing else). If your dish is slightly out of alignment, the analogue PAL signal from 1D could completely obliterate the digital signal from 2D on the same frequency. This would mean you'll get about the same signal strength reading, but the 'quality' reading will be much worse than the other 2D transponders.

 

July 1, 2003 update. This transmission has apparently been switched off.

[Mr. Bun]

The seemingly reduced signal strength on 10773H occurs relatively often (around 2-4 days/week, I'd guess). Other transponders are, to my knowledge, not affected.

 

The - to me - striking thing about the low signal strength value is that it is stuck at 26% - none of the usual fluctuations of +/- 1-2% that one normally sees. Despite that the reception is - weather permitting - generally flawless.

 

That suggests to me that this is not a real reduction in signal strength but rather that whatever it is the SkyStar2 (and/or its driver) uses to calculate signal strength is either not being transmitted at all or transmitted in a way that the SkyStar2 can't deal with properly and consequently gives its minimum signal strength value. (When the SkyStar2 is disconnected from the LNB it's also 26% - not 0%).

 

But then it got very low - I could still watch BBC, but the slightest rain killed it.

<{POST_SNAPBACK}>

It seems likely that that was just a coincidence.

 

the analogue PAL signal from 1D could completely obliterate the digital signal from 2D on the same frequency.

I doubt that the problem is caused by interference from another sattelite because

1. Astra 1D has - according to Lyngsat - since moved on to 23.5°E where it is now tranmitting HD programmes,
   
2. a cursory check of the adjacent sattelites' transponder lists didn't reveal any transmissions on 10773 H (or V, for that matter) and
   
3. I've made numerous recordings at 26% signal strength from that transponder without even a single stream error.
   

Might be interesting to know what experience non-SkyStar2 users have with this issue.

[Griga]

The seemingly reduced signal strength on 10773H occurs relatively often (around 2-4 days/week, I'd guess).

Good to know I'm not the only one

 

The - to me - striking thing about the low signal strength value is that it is stuck at 26%

The value in the status bar (as far as it concerns the SkyStar2) is more related to the signal quality, as stated in the TechniSat SDK. A low signal strength decreases the quality resp. increases the bit error rate, of course, but there may be other reasons, like the Astra 19° East 12480 V DECT issue.

 

I've made numerous recordings at 26% signal strength from that transponder without even a single stream error.

Yes, under good weather conditions it's still ok. But a drizzle may already cause lost data packets in this state, as I've experienced, while other 28° East transponders (with the "above 40" signal quality) are not affected.

[Derrick]

With DTH satellites the TWT amps normally have a fixed working point. IMHO the observed deterioration is caused by other satellites. The beamwidth of small dishes is simply too wide.

[Griga]

I've moved this topic back to its original location.

 

The beamwidth of small dishes is simply too wide.

I think you are right. I have only been waiting for your final statement.

[cunningh72]

Can anyone confirm problems with the BBC transponder 10773 H on Astra 28° East? I have not been able to receive anything on this frequency for the last couple of days - my decoder says that there is no signal at 10773 MHz

[txrx]

Can anyone confirm problems with the BBC transponder 10773 H on Astra 28° East? I have not been able to receive anything on this frequency for the last couple of days - my decoder says that there is no signal at 10773 MHz

 

I had initial problems picking up BBC news 24 (signal strength was 10%) but now it's fine. I reckon it may have been some form of protocol malfunction on those feeds. I'd rescan again since it's solid now. I can also get BBC 4 and BBC 3, which somehow shows CBBC before the channels go live at 7pm!

 

 

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Skystar2 + DVBViewer pro

pointed at 28.2 east in the UK.