TBS 6925 PCi Card with hardware blind scan in DVB-S2 and DVB-S

[remlap]

Very odd feed at 24.5w

1080p 24fps AC3 audio running at 75 mbit/s

11596 V 30000 DVB-S2 8PSK 5/6 Pilot Off but it is not DVB transport stream but TSReader can still see the PID's

 

[Llew]

Interesting. I understood TSReader only accepts TS sources. Will check that one if it's still up.

 

[Llew]

Well the video stream is tiny compared to the rest of the data. Good of them to have the test card running, at least we can see who's uplinking it

 

[Vipersan]

Hi Friends ..
Not sure If this will upload ...but gonna try..
I'm back to the Fox 32psk feed on 55west Cband

Still confused by this ...more so since I opened TBS recorder and watched the comings and goings of this odd signal/feed.
As mentioned before the feed will eventually crash the TBS card requiring a reboot of the pc if left running ..
So a quick view to make sure its present ...then activate TBS recorder ..
Watch the signal level bar ..
It doesn't change over much ..and yet the modulation changes between QPSK 8PSK sometimes 16PSK ..and 32PSK ..

Also and oddity is that the FEC changes ...which I didn't think was possible ..unless its deliberate of course..
Sometimes the card loses lock ...and the link to the feed has to be re-established ..
No wonder it crashes the card ..but I don't think its lack of signal ..
Any further thoughts on this odd feed are welcome
rgds
VS
The zip contains a compressed flash clip ..click on the internet explorer icon to run the swf...assuming it uploads that is ..

It appears to have uploaded ok ...so feedback as to... if the swf runs ok would be appreciated ..
Its the first time I've used Camstudio..

 

[Huevos]

feedback as to... if the swf runs ok would be appreciated ..

It doesn't run for me.

 

[Vipersan]

Thanks for tryimg Huevos ..
May be that it will only run on the machine on which it was made ..
I can test this by opening the zip on a laptop ...and running from there ..
It may be that Cam studio installs something that allows it to run ..
I'll test and report back.
Cheers m8
VS

 

[Analoguesat]

Runs ok here VS (opening using IE8).

 

[aceb]

Works here in FF if I open file from the menu and click on the SWF, clicking on the html file in the zip and nothing happens once the page opens, just remains blank.

 

[Llew]

Working here on my WinXP/IE8 VS after a warning on whether I want to run the file. I see the video and the parameter changes, indeed strange. Don't have access to that feed so can't observe it myself.

 

[Vipersan]

Thanks guys ..
Yep ..just tried in on a vista laptop ..
Runs no problem once you accept the warning message concerning scripts which ie pops up ..
Perfectly save to accept ..
It just warns against scripts and security issues..

Llew ..
Thanks for confiming the oddity ..
It looks like the fec's and modulation are rotated ...errr...deliberately ?

curiouser and curiouser..
rgds
VS

...Also ...it looks like Camstudio might be a very useful tool/addition to the armoury

 

[Vipersan]

....The other possibility which occurred ..is that the TBS card isn't yet 100% compatible with 32psk ...and this 'instability' causes the card to lose lock ..so having to reconnect to the transponder/stream
just a thought..
rgds
VS

 

[Vipersan]

..Just out of interest ..I have yet to successfuly stay locked on a 32psk signal long enough to generate a 32psk constellation diagram to completion ..
Here are some near perfect examples of Qpsk 8psk & 16psk from my collection ..
this 32psk signal refuses to produce an constellation as I would expect it to appear
rgds
VS

 

[strs65]

Hi Friends ..
Not sure If this will upload ...but gonna try..
I'm back to the Fox 32psk feed on 55west Cband

Still confused by this ...more so since I opened TBS recorder and watched the comings and goings of this odd signal/feed.
As mentioned before the feed will eventually crash the TBS card requiring a reboot of the pc if left running ..
So a quick view to make sure its present ...then activate TBS recorder ..
Watch the signal level bar ..
It doesn't change over much ..and yet the modulation changes between QPSK 8PSK sometimes 16PSK ..and 32PSK ..

Also and oddity is that the FEC changes ...which I didn't think was possible ..unless its deliberate of course..

Yes, but that's the whole point of an ACM/VCM modulation I believe. Transmission parameters are changing due to reception quality and bandwidth needs.

The zip contains a compressed flash clip ..click on the internet explorer icon to run the swf...assuming it uploads that is ..

It appears to have uploaded ok ...so feedback as to... if the swf runs ok would be appreciated ..
Its the first time I've used Camstudio..

Runs without a problem here with FF...

Btw, check this pdf. I think it's quite interesting...

_http://www.paradise.co.uk/collateral/articles/207702p1-.pdf

 

[Vipersan]

Yes, but that's the whole point of an ACM/VCM modulation I believe. Transmission parameters are changing due to reception quality and bandwidth needs.



Runs without a problem here with FF...

Makes sense Strs ...
Its a whole new learning curve for me ...but if the signal is constantly changing ...how can any receiver get a solid lock ...
...unless the 'key' is transmitted in the data stream at the lowest modulation level perhaps ..
Of course I may have totally missunderstood ...but I am trying to get my head around it..
rgds
VS

 

[strs65]

I quote a relevant paragraph from the pdf (read the rest, it explains some things)

A key point is that the PL header is always transmitted
using a particular robust modulation (BPSK is used in the
DVB-S2 standard) and strong FEC rate. This helps the
receiver lock onto the signal and it provides the information
required to demodulate the remainder of the frame.
When not receiving a signal, the receiver is automatically
configured to detect any PL header, requiring just a
centre frequency and symbol rate to have been set.

 

[Vipersan]

..Hmmm ..
I guess if the intended reception device is capable of rapidly switching modulation and parameters fast enough ...the data stream would be maintained ..
This would make for very very efficient use of the available bandwidth ..
But my gawd ..that would have to be one very fast and truely organic reception device/tuner..
Out of our purely amateur league for the moment I suspect.
My brain hurts...
VS

...I'm thinking out loud atm ..but this would totally explain ...why the TBS can for short periods produce a locked stream ..
..only to fail ..once the fec/ modulation changes ..
It can't adapt rapidly enough ..
Its not that it can't demodulate the stream correctly ...it can't adapt quickly enough thus losing lock without being forced or allowed to relock to the new parameters..
Doh ..
Foolish me ...

Can't say I'm not dissapointed at not being able to lock this stream ....but appreciate the 'beauty' of what is being demonstrated..

 

[strs65]

I guess so. Anyway those transmissions are not intended for reception with normal everyday DVB tuners. They also provide a return path, so the satellite will know what the reception conditions are to adjust the parameters accordingly.

 

[Vipersan]

I guess so. Anyway those transmissions are not intended for reception with normal everyday DVB tuners. They also provide a return path, so the satellite will know what the reception conditions are to adjust the parameters accordingly.

I considered the idea of the return path ...
but threw me a curved ball a bit ..
If this operation destined for the US only ...but the wider footprint aimed both at the US and mainland Europe was what put me off the idea ..
just trying to imagine the amount of power needed to uplink a return path on both footprints ..
Yep ..thats what threw me ...but totally not ridiculous..and definately do-able.
rgds
VS

...of course ...
I'm thinking too linearly here ...
No reason the return path has to be satellite based ..
High speed internet connections could easily achieve this ..

 

[strs65]

I believe you may also like this one...

_http://www.newtec.eu/flexacm

 

[Vipersan]

I believe you may also like this one...

_http://www.newtec.eu/flexacm

Thanks for the link m8 ..
Thats definately it ...
I was witnessing Flex ACM in action ..
Its truely beautiful in its simplicity (not the idea or the technology behind it)

..on the downside ..it will probably shut out amateur feed and data hunting ..eventually ..

..and thats a sad epitath..

I'm happy we managed to make sense of the oddity though ...even before we knew what it actually was..
rgds
VS