Cannot tune to some transponders

[fcxpress]

Hello Community,

Since a few months, I can not more tune to some transponders.
The channels I'm trying to get are AB3 and AB4 on 13° (please check on kingofsat, lyngsat, etc for channels details).
When I request my VU+ solo to tune on those channels, it stucks to a signals arrond 33% and cannot go higher. Then the signals flaps to 0% and back to 33% and so on.
Problem appeard end of March/begining of April 2011. Before that it always worked.
I can see multiple "FE tune" entries when issuing dmesg command and I can also see multiple lines "Jun 30 15:10:18 vusolo user.warn kernel: FE tune" (timestamp varies of course) in the /var/log/messages files.
I'm running on BH 1.6.2.
My setup is a monobloc DiSEcQ LNB with head A on 13° and head B on 19.2°.
Tunner config in BH is auto DiSEcQ A/B with A on 13° and B on 19.2.
Plenty of other channels on 13° work perfectly and I think I cannot see any channel of this particular transponder and they all have the same problem.
Can you please help me on that or even tell me what to do to grab more information on the problem in order to troubleshoot it ?

Many thanks,
fcxpress

 

[>>Artorius<<]

hmm, what are the frequency details ? and have you updated your satellite.xml ?

 

[fcxpress]

Thanks Artorius for answering that quickly!

I did what you suggested and updated my satellite.xml file: Goggled for it, found a website that makes up-to-date satellites.xml, generated one for my config, uploaded it to my box and rebooted.
[file attached]
Then I performed an "auto search for channels" and a "download sevice list".Unfortunately this didn't solve my problem.

Here are the channel details (this is just an example, I have plenty of other channels with the same behavior that worked before and do no more work now):
Channel name: AB3, Sat position: Hotbird 13°, freq: 12692000, pol: H, Symbol rate: 27500000, FEQ: 3/4, standard: DVB-S

But the story is not over yet...

After have done that, the problem now occurs with other channels.
I now have the problem on Canal+ HD France. Same symptoms: signal ratio tops at 32% then falls to 0+ then it flaps between those two values.
Channel name: Canal+ HD, Sat position: Astra 19.2°, freq: 12012000, pol: V, Symbol rate: 27500000, FEQ 3/4; standard: DVB-S2

This is a different sat and frequency and polarization are different.

After that I performed a factory reset of the box but the problem remains with those two channels (and the plenty of others).
Can I please emphasis that Canal+ HD France did work this morning.

I suspect this is a cable, tunner or LNB problem but I really don't know.
Any hint to troubleshoot this further would be much appreciated.

Cheers,
FCXpress

 

[Matrix10]

I have an opinion that your problem is your SAT installation
and not a box and image .

Are you sure that your antenna is well tuned to 13 e ??
What kind of signal strength you have on the other transponders ??

 

[fcxpress]

Antenna installation was done by a professionnal and he fine-tunned it.
This morning I had Canal+ HD at 94%, now it has fallen to 32%.
For some other transponders on the same sats, I have 95% signal.
Maybe I should try with another box on my installation and try my box on a similar installation.
I'm not sure about DiSECq settings neither. I just put DiSECq A/B with A on 13° and B on 19.2° and left the default settings.
This worked before without any problem, so IMHO this must be the box. Either sat/chan settings or maybe some HW problem.
I also tried to update the drivers following the procedure available in this forum. Update worked but problem remains...

 

[Matrix10]

It seems to me that all channels where you have problems operating at higher frequencies
if the channels on Astra are working at higher frequencies without problems
then the problem is LNB.

So if you have a good reception of channels on Astra at similar frequencies
then the problem can not be a tuner in box and the box,
but probably LNB.

In the box there is only one tuner for all satellites
and not specifically for Astra and HB 13 E especially.

A modern "universal" LNB is able to operate in four modes to provide signals from four frequency bands, known as "low-horizontal", "high-horizontal", "low-vertical" and "high-vertical". An LNB may have more than one output but any one output can provide only ONE of these bands at a time.
In order to tell the LNB output which of the four frequency bands it needs to provide, the receiver "communicates" with the LNB as follows (this gets technical):-
A modern "Universal" LNB requires a 22 kHz signal at 0.5v p-p to switch its Local Oscillator to 10.6 GHz ("high band"). Otherwise it uses its 9.75 GHz oscillator.
Polarisation switching is controlled by DC voltage supplied by the receiver. 12.5v to 14.5v gives vertical and 15.5 to 18v gives horizontal polarisation. A higher voltage than that can damage the LNB. A voltage that is too low will prevent the LNB from working correctly.

 

[a911]

I agree 100% with MX10, it may be LNB issue, however can U post a shut of U'R tuner settings....!

 

[fcxpress]

Thank you Matrix10 and a911 for these valuable advices.
I did some tests and took the box out to another installation on a friend's antenna and LNB.
The box behaves the exact same on my friend's install, meaning the problem is on the box. Either hardware (which I hope not...) or software.
I already tried to update the satellites.xml file but I just realized that I upload my settings with dreamset and this software comes with a very outdated satellite.xml file in its directory structure. I don't know if dreamset uses to upload its own sattelite.xml but I replaced it in the directory of dreamset as well.
Will try that when I get home tonight.
Some test that I must do also is wipe everything out from my box and install the latest vu+ official image with just the needed files for the box to operate (no chan settings or anything such) and try again to tune to those channels. That's a good way to know if the problem is hardware or software.

Again, many thanks for your advices!
I will keep you updated.

 

[Matrix10]

We have on the server settings with which you can test.
Green button>>Yellow>>Addons Download Manager>>Settings

 

[fcxpress]

Here is an update: this is not due to dreamset.
I performed the same test after having changed satellites.xml and problem remains.
Nevertheless, I deleted my settings and performed a fresh scan of channels.
Some were recovered, some were not.
Something else I noticed, is that I used the satelite pointer to make a test and check signal quality for the transponder I have a problem with.
For AB3 on sat Hotbird 13°, freq 12692000, sr 27500000 feq 3/4, I've got 77% signal.
Problem is that I have this result only when using option "predefined transponders", which I suppose relies on the satellites.xml file.
For Canal+ HD on the other transponder, other sat, good result as well.
Please see attached screenshots.





When I exist the satellite pointer menu, I have the impression that it falls back to manual mode
When performing a auto search, AB3 (for example) is not detected.
Is there any way to force the box to use predefined transponders in satellite.xml file to perform its auto channel search ?
Also, can you confirm these tuner settings are correct for my setup (monobloc LNB with A on 13° and B on 19.2°) ?
"Use 22kHz and voltage" --> yes
"Use DiSECq only to change sat" --> yes
Can you provide a procedure to wipe everything in channels, tuner settings and so on and perform a clean scan from scratch?

Thanks for the channel settings available on the server, I knew about it but never tried it. This is certainly something to try.

Many thanks for support!
Cheers,
FCXpress

 

[fcxpress]

FIXED!

I deleted all the channels and settings and performed an auto scan.
This did not give the result I expected as AB3 and AB4 channels did not appear in the list of all channels (Channel+ --> RED).

I then performed a manual scan, entering the transponder details (sat, frequency, polirization, s/r, fec and modulation) after having retrieved them from kingofsat.net.
Then I get the channels I was missing.
I must be missing plenty of other channels that I don't even know about...

This means the settings I used and the auto scan feature are not up to date or implemented properly in the image.
If user have to perform a manual scan on every transponder to get all channels, this is going to a real mess...
I there any option for enabling tunner debgging ?
I willing to help the team to have that fixed for the next release.

 

[fcxpress]

Something important to point out is that those particular transponders I had problems with all use the 8PSK standard for modulation while many others were using QPSK. I didn't notice a problem with QPSK channels so far.
Could it be that my tunner or the drivers do not handle correctly changing type of modulation when a zap action is requested ?
Same problem also with auto scan ?

 

[>>Artorius<<]

Going back over what has been covered, have you tried the latest settings from C@jton which includes an updated satellite.xml based on KOS frequencies ?

 

[Matrix10]

I use a satellite settings from @ Likra

And these channels are standard in this list.