4.2.2 DVBS-2 feeds - help

[ManikM]

sometimes when a 4.2.2 feed is advertised, in DVBS-2 - i always find it a bit of a faff with the AZBOX to tune it in cos the FEC = AUTO never seems to work.

a few questions if you dont mind please chaps.

whats is the difference between DVBS-2 QSPK, and DVBS-2 8SPK ? (feeds dont normally mention if its one or the other)

what does PILOT - on or off mean when tuning in a feed.

concerning the AZBOX a while ago, i was told that when tuning in a feed, the FEC if set to auto doesnt work, and you have to scroll through each one in turn before the signal will show (orange bar)

taking this into account and not knowing if a feed is DVBS-2 QSPK or DVBS-2 8SPK - this means a lot of faffing about when tuning in a feed.

therefore i thought it was "normal" to go through each possible combination p, i.e DVBS2-QSPK, then go thru each FEC with Pilot ON, then repeat with Pilot OFF, then change to DVBS2-8SPK, and repeat each FEC with Pilot ON and then Pilot OFF until the signal comes in.

what do you guys do? any hints?

you can see how this has come about here:
https://www.satpimps.co.uk/showthread.php?t=138096&page=2

cheers all!

[Eugenie]

_http://www.hellas-sat.net/files/file/EBU_DVB_S2.pdf
see (Forward Error Correction (FEC) and modulation)

_http://www.arctekhd.com/news/stories/DVBS-2_guide.pdf
see 4.1.1 (Cycle Slips, Phase Noise and Pilot Tones)
see 4.1 (The Modulation Scheme)

'this means a lot of faffing about when tuning '...yepp, that can often be the case

[kebien]

sometimes when a 4.2.2 feed is advertised, in DVBS-2 - i always find it a bit of a faff with the AZBOX to tune it in cos the FEC = AUTO never seems to work.
This is because there is no way to find the FEC automatically using DVB-S2.(for azbox )



a few questions if you dont mind please chaps.

whats is the difference between DVBS-2 QSPK, and DVBS-2 8SPK ? (feeds dont normally mention if its one or the other)

what does PILOT - on or off mean when tuning in a feed.
You won't probably understand in technical terms,but this are two different types of modulation and the ones uplinking the feeds decide to use to their convenience (there are many factors they can choose one over the other)

Pilot is a test signal uplinked together with the feed to help tuning the signal,it can be present or can not be there,decided by the uplinker.




concerning the AZBOX a while ago, i was told that when tuning in a feed, the FEC if set to auto doesnt work, and you have to scroll through each one in turn before the signal will show (orange bar)

taking this into account and not knowing if a feed is DVBS-2 QSPK or DVBS-2 8SPK - this means a lot of faffing about when tuning in a feed.

therefore i thought it was "normal" to go through each possible combination p, i.e DVBS2-QSPK, then go thru each FEC with Pilot ON, then repeat with Pilot OFF, then change to DVBS2-8SPK, and repeat each FEC with Pilot ON and then Pilot OFF until the signal comes in.

what do you guys do? any hints?

you can see how this has come about here:
https://www.satpimps.co.uk/showthread.php?t=138096&page=2

cheers all!
yes,we all do what the box let you do.
If you need to test the specs one by one,then do it,since is the only way for you to find it.
Other boxes do not need more than the frequency and symbol rate to lock on a DVB-S2 feed,like vantage 8000.

[xanadu]

Other boxes do not need more than the frequency and symbol rate to lock on a DVB-S2 feed,like vantage 8000.

And like Azbox HD.

Mine only needs SR and Frequency.

[ManikM]

And like Azbox HD.

Mine only needs SR and Frequency.


haha, i didnt think it would be long before you commented mate.

i want to know what OTHER Azbox owners do, it can't just be us to that tune into feeds.

LOL!

[satwyn]

This is because there is no way to find the FEC automatically using DVB-S2.(for azbox )


You won't probably understand in technical terms,but this are two different types of modulation and the ones uplinking the feeds decide to use to their convenience (there are many factors they can choose one over the other)

Pilot is a test signal uplinked together with the feed to help tuning the signal,it can be present or can not be there,decided by the uplinker.



yes,we all do what the box let you do.
If you need to test the specs one by one,then do it,since is the only way for you to find it.
Other boxes do not need more than the frequency and symbol rate to lock on a DVB-S2 feed,like vantage 8000.but no 4.2.2 decoding with most receivers including the vantage

[tsakman]

With azbox premium all the Dvb-s2 channels/feeds must have the correct fec and pilot

With Auto Fec

http://img6.imageshack.us/img6/716/sat1.png

With manual fec

http://img202.imageshack.us/img202/596/sat2.png

[fcis7000e+]

Hi,

Interesting topic.

And what about Azbox blind scan function, can't it be used to find the feed, using only the frequency and symbol rate?

[tsakman]

Azbox "blindscan"

http://img189.imageshack.us/img189/117/blindv.png

All manual

[fcis7000e+]

Azbox "blindscan"

http://img189.imageshack.us/img189/117/blindv.png

All manual

Does it mean that the AZbox blind scan doesn't scan automatically all the modulation types, FEC and Pilot for a certain range of frequencies and a certain SR (or SR ranges)?

If not, in which cases is useful the use of Azbox blind scan? (namely for the blind scan implemented by software as is the case of my Elite)

Thanks.

[jamesjay]

Hi,

Just a quick comment...the blind scan on the AZ+ or the AZ and Elite are not perfect for feed-hunting because of the limited options in the Symbol Rate, the SR of most feeds is below 8000 so it would help with the blind-scan speed of the box if it had a maximum SR, that would cut down on a time consuming full SR scan every-time and allow for quicker scans and more Sats to be searched in a given time.

In fact the Minimum and Maximum Frequency range is not really of any use or ornament, because if your doing a true blind-scan (no transponder details) you would always scan the full frequency range anyway, but for most sport feeds not the full SR range.

Regards

James.

[ManikM]

With azbox premium all the Dvb-s2 channels/feeds must have the correct fec and pilot

With Auto Fec

http://img6.imageshack.us/img6/716/sat1.png

With manual fec

http://img202.imageshack.us/img202/596/sat2.png

hi mate, thanks for confirming, although you are HIGHLIGHTING "PILOT" on and off in your screen grabs, not FEC.

i really dont understand XANADU then, because he insists that he NEVER puts the FEC in and leaves it on AUTO FEC and
im sure he's not lying, LOL

im very puzzled, but im glad that you concur with my findings.

:respect-067:

[kebien]

And like Azbox HD.

Mine only needs SR and Frequency.

And ,obviously,ManikM DOES NOT have the model you have,or he wouldn't be asking this questions.
Or maybe you didn't get that from his post?

[kebien]

but no 4.2.2 decoding with most receivers including the vantage

And what is a 4:2:2 chroma type has to do with tuning DVB-S2?
This two things has NOTHING in common,not related.
Even the original poster have no clear understanding about one or the other,this thread SHOULD help him understand.

In the elite,DVB-S2 using FEC to auto doesn't work.
It only works for DVB-S.

[ManikM]

And what is a 4:2:2 chroma type has to do with tuning DVB-S2?
This two things has NOTHING in common,not related.
Even the original poster have no clear understanding about one or the other,this thread SHOULD help him understand.

In the elite,DVB-S2 using FEC to auto doesn't work.
It only works for DVB-S.

i thought the AZBOX Elite, Premium, and Premium PLUS, uses the same firmware, therefore, the issue would happen on any model.

i beleive Xanadu has the Premium, as do I

yes, the 4.2.2 fact is NOT the issue, just the scanning in a freq on DVB-S2.

[kebien]

You said it : they all use same firmware.
But hardware is different in the models with blindscan (tuner wise),which could make a difference.
I believe this is a general feature ( DVB-S2 FEC set to auto does not work) for Elite and premium,this is the first post I read that says otherwise.

[jamesjay]

From what I have read in posts on various sites but mainly on here...the difference between the Premium and Elite and the Premium+, is that the + uses an hardware and firmware based blind-scan, not sure about the tuners but a bigger main-board was needed on the +, unlike the Premium and Elite that is solely software based or forced (whatever that means).

Having said that, I have the Premium+ and still have problems when manually putting in transponder details from an advertised feed whether it is 4.2.0 or 4.2.2, sometimes it locks on to the transponder and sometimes I have to play with it, a good description of the + is finicky even when you have the transponder details to hand.

[ManikM]

cheers guys, lets see what Xanadu has to say when he gets back on here, although he did say he has a Premium+ (Plus model), but said his old Premium HD (i presume the Elite model) was exactly the same.

[xanadu]

Manikm- Try this one

Eutelsat W1 (10.0°E)
Frequency: 11673 - Pol: V - SR: 7120 - FEC: 3/4

West Ham-Chelsea /(dvb-s2/hdtv)

All I did was add as a new transponder with FEC as AUTO. NO PILOT.
I know it's 3/4 but I just left as AUTO.

Then...in advanced tuning menu...select the new transponder from the list

Signal appears immediately. Scans in as ARW FAPL-1

This channel is Encrypted, but that's irrelevant to this test.

As I said before I never set the FEC manually, and as far as I can remember never had to on my previous HD Premium model.

Maybe kebian is right in saying this this may only be something that only the Premium Plus does for DVB-S2 channels.

DVB-S channels as kebian says should work with FEC set to AUTO.