DVB-S2 8PSK Signals

[Electro960]

Greetings!

Anyone able to provide me with some tips on how to receive DVB-S2 8PSK signals via a 6ft satellite dish? I am using an AZBox Elite with a C/Ku band LNB (see attached for specs) and I still do not have any luck receiving DVB-S2 8PSK signals, even on Ku band. I recall a post a few months back from Scott about this issue but don't recall what the resolution was. However, I do recall a mention about needing a 10 footer to receiving this signal but shouldn't I be able to pick this up on Ku with a 6 foot? Assistance would be appreciated. Thanks.

 

[putney]

I get them with my 8' unimesh but your sat has to be dead on.

With the amount of tweaking I have to do with mine, getting S2 with a 6 footer is going to be a struggle.

With my Az, S2 signals nee about 65% to lock (some lock at 62%)

 

[Electro960]

WOW! An 8-footer even for Ku band?

I get them with my 8' unimesh but your sat has to be dead on.

With the amount of tweaking I have to do with mine, getting S2 with a 6 footer is going to be a struggle.

With my Az, S2 signals nee about 65% to lock (some lock at 62%)

 

[qwert1515]

WOW! An 8-footer even for Ku band?

No, I am pretty sure Putney is talking about C-Band.

I can get Ku-Band DVB-S2 with my 1.2 Meter dish.

Dish alignment has to be perfect, even a loose cable can mess up DVB-S2 reception.

 

[pro96]

I get KU DVB-S2 with 76cm dish and if needed a 1.2m which is more then enough.
CBAND on the other hand, if the code rate is 3/5 then you will be ok with CBAND but if its not then you will have a hella of a time locking in a decent signal.

 

[Electro960]

Thanks for the feedback. Guess I'll have to try harder. Once this format becomes mainstream I guess it'll be more difficult to catch C-band reception.

 

[Electro960]

BTW, shouldn't a 6 footer be picking the NBC mux on AMC 1 Ku? I'm on a mission to get this to work, no matter what it takes!!!:rant:

 

[Jim S.]

The skew on AMC1 Ku is 26 degrees off from where it's supposed to be. I'm not sure if that would make a difference on a 6-footer though. You might have enough signal to overcome the loss.

 

[ynnedibanez]

is the dish you mention a c-band dish with a c/ku lnb on it?

 

[Electro960]

Yes

is the dish you mention a c-band dish with a c/ku lnb on it?

 

[edyvick]

trying to get dvb-s2 channels, no luck what so ever.

I get KU DVB-S2 with 76cm dish and if needed a 1.2m which is more then enough.
CBAND on the other hand, if the code rate is 3/5 then you will be ok with CBAND but if its not then you will have a hella of a time locking in a decent signal.

hey! I have tried to get dvb-s2 signals from my 76 cm Ku dish, but so far, no luck. Would you be kind and tell me what channels you are receiving and, of course, the parameters. Thank you very much...

 

[Tron]

Electro960, what kind of LNB are you using on your 6 footer, and what type of 6 footer (offset or prime focus) is it? I'm betting its a Fortec or similar (such as the new Sadoun) prime focus 6 footer. If it is, you'll need a Ku-Band LNBF designed for a prime focus dish, or a prime focus Ku-Band feedhorn such as the Invacom ADF-120 mated to a C-120 flanged Ku-Band LNB.

 

[guacharaca]

OETA (PBS) at AMC 21, 12112V 8703 - 3/4, 8psk is your easiest starting point for receiving a DVB-S2 signal on ku. Now receiving a good signal with 1.2 m dish in BC.

 

[Electro960]

Tron,

You got it right. Its the fortec 6 footer with LNB sold by Sadoun. I've attached the specs of the LNBF on the first post. Looks like I'll need to invest in a seperate Ku-Band LNBF as you mentioned. Its gonna be a pain in the neck switching from C-band to Ku-band LNBF, something I'll have to do manually each time I guess. Thanks for the suggestion, I'll give it a try.

Electro960, what kind of LNB are you using on your 6 footer, and what type of 6 footer (offset or prime focus) is it? I'm betting its a Fortec or similar (such as the new Sadoun) prime focus 6 footer. If it is, you'll need a Ku-Band LNBF designed for a prime focus dish, or a prime focus Ku-Band feedhorn such as the Invacom ADF-120 mated to a C-120 flanged Ku-Band LNB.

 

[Tron]

The LNBF designed for an offset dish will only see a small part of the dish. It works much like a telephoto camera lens, while an LNB using a prime focus feedhorn works like a wide angle camera lens.

That being said, I read your original post more carefully and noted that you are using a C/Ku combo LNBF. Those ARE designed for prime focus dishes, so that won't be the problem. What probably IS the problem, though, is that these C/Ku LNBFs are notorious for being difficult to adjust so that they'll get both C and Ku-Bands simultaneously.

 

[brentb636]

"....notorious for being difficult to adjust so that they'll get both C and Ku-Bands simultaneously."
This is particularly true on smaller Prime focus dishes. I started out my miniBUD with one of these, and briefly could pick up some Ku and some C-band at the same time. Optimizing for C-band , though, which was the point of the whole thing, I lost Ku altogether.

 

[hd fan]

C/Ku on that 6 prime footer is doable but requieres a lot of teawking, specially if it is motorised. you live in the east coast so try those 55W C band 8PSK muxes from different latin american countries. Here in toronto I have not had success with the PBS's 8PSK on 125W yet. You could also try the uruguayan mux on 30W which is also powerful with my 80 cm offset.

After almost perfectly aligning the LNB for 0 skew and focal distance on my motorised prime 6'fortec I could still not get Ku past 99W (and the ones I got were not great) but then after fixing the mount cap now finally plumb I get all ku with great signals all the way up to 127W. Like I said it is doable but it requieres a lot of tweaking and perfect adjustments. But even after that do not expect to lock to 8PSK signals with FEC over 3/4 on either band (I am yet to receive my first 5/6 FEC 8PSK). For that you requiere a bigger dish , in this case , the saying fits perfectly , the bigger the better.

Well I hope the earthquake in Ottawa did not heave my dish pole!.

 

[B.J.]

I agree with most of the above. Myself, I have a much harder time on Ku than on C-band. Only reason I can think is that the LNBFs I'm using on Ku are lower quality than the LNBs I use on the BUD.

However, the reason for response is that since the OP'er is using an Azbox, I wanted to make sure that the problem wasn't one of technique. Ie with my Elite, generally I have to have all the parameters correct or it won't lock, including both FEC and pilot on/off. When you go into the Azbox, and set up the parameters, generally the signal/quality meter doesn't function. So what I do, is just go into the transponder edit screen, and set up the transponder with DVB-S2 parameters, THEN, I exit that menu, THEN, I go back into that transponder I just created, and one by one step through all the FEC values on both pilot on and pilot off. Generally I'll hit on the proper parameters. Most of the time, when you get DVB-S2 transponder parameters from a list, they don't tell you all the parameters, particularly the pilot, so you have to experiment, however with the Azbox, you can't experiment until after you have created the transponder, exited that page, and gone back into edit again.

At least that is the way MY Azbox behaves. There is a guy over at Satforums, who swears up and down that you absolutely cannot do what I do. Ie he says that with his Azbox, once you create the transponder, that you cannot edit it to change to the proper parameters. I am really confused as to why his Azbox would be so different from mine.

Anyway, that's the technique I've used, and I've been able to lock 90% of the S2 signals I've seen listed. I generally cannot lock the Ku NBC on AMC1, however, due to the 26 deg skew offset with my 3' dish, and the fact that my BUD has too many dents and is too warped to work well on Ku. But most other sats work OK.

One other thing re Azbox and S2. If you get a lock with 7/8 FEC, that is the wrong FEC. It shouldn't be in the S2 menu, and you get confused results sometimes.