PCTV 290e dvb-t2 signal problems after update

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thon
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PCTV 290e dvb-t2 signal problems after update

Post by thon » Mon Dec 01, 2014 10:10 am

so i have been running my 290e stick fine for over a year on mythbuntu 12.04 with linux 3.2 kernel, then in a moment of madeness last week i decided to upgrade to 14.04 lts. Apart from grub installing on the wrong drive everything went well. The problem came when scanning for HD channels on the 290e stick. I couldnt get a lock on any of the HD multiplexes (2 in my case UHF 32 and 41). Manual tuning didnt work either. What did work was scanning for all multiplexes with my other dvb-t card, then manually changing the sourceid field in the Dtv_multiplex table. After setting this the 290e stick found all the channels on both multiplexes.

Now the main problem is that when i try to watch or record from the HD channels the video is extremly blocky or dark basically unwatchable, the audio and CC are fine however. Previously recorded SD and HD content plays back fine, so its not a driver issue nvidia/vdpau. The aerial connections to the tuner cards havent moved, the only thing that has changed is the upgrade to mythbuntu 14.04 lts.

The OSD shows that the signal is at 100% but the quality is low either 0 or 2.4db (something like that). Another issue is that i cant get the signal monitor to show, ive tried to rebind the key, but when i press it, the osd comes back, without the signal info stuff and move often than not causes some for of crash that drops me back to the main menu.

The 290e is currently using the em28xx driver, im unsure what it was using before as it was so long ago that i installed it. I know that the 290e has a LNA but in not sure if its enabled or not or even how to enable/disable it to see if that has changed in the upgrade

I know that there has been quite a bit of work on the em28xx driver between 3.2 and 3.13 so does anyone know whats changed or happened in my situation

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Mon Dec 01, 2014 5:03 pm

My 290e is running fine on 14.04.
But I did have to check signal levels and re-configure my aerial so maybe the gain is different.
To check install 'femon'.
Which on my system gives :-
femon -a 102 -H
FE: Sony CXD2820R (DVBT)
status SCVYL | signal 71% | snr 0% | ber 0 | unc 0 | FE_HAS_LOCK
The -a param references the dvb adaptor number, leave it blank if you only have one.
Mine was unreliable producing occasional blank recordings with a 60% signal.
I also find that reliability increases if you only allow the simultneous reception of 2 channels. When running on an atom processor only one worked reliably.
With a 70% signal I get 100% reliability.

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Fri Dec 05, 2014 10:38 pm

Well I tried femon which gave me a 100% signal with 0% snr. Using a variable signal attenuator I could get the signal as low as 60% but still the snr showed 0%. checking with my other tuners nova-t 500 I had a signal of about 70% with a snr of 0% as well except that the dvb-t tuners all get perfect recordings. Is there anything else I can try that will show me the snr of my tuners as I don't think femon snr is accurate.

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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Sat Dec 06, 2014 5:08 pm

I dont know of any other tool besides femon. If you normally get 100% signal I would suspect that could overload the PCTV 290e. Leaving the attenuator in and bringing the signal down a bit might help matters.
What sort of failure rate are you experiencing and how many channels do you allow simultaneously.

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Sat Dec 06, 2014 6:22 pm

Well that's the thing before I upgraded I set it for 3 channels and could record 3 hd channels to disk with no error (max I tried was 2 hd channels and 3 sd on different multiplexs) so I know it was working really well. Now I have it set for 2 channels and the recordings either fail or are extremely bad.

I wonder if it's something to do with the usb subsystem as I have in the past had tuners that would randomly disconnect, I got rid of them pretty quick.

I think my next step is to either try it in windows, but I haven't got a clue what software to try, or pull all my disks out and try a fresh install on a spare hard drive. Is it possible to have a full BE and FE running off a live disk?

Edit: Excuse the spelling and grammar auto correct on my phone is well you get the idea

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Sat Dec 06, 2014 8:12 pm

I've just tried it on windows using pctv's TVCenter software and it works perfectly signal shows as 100% with snr/quality at about 70% for dvb-t2, and for dvbt it's 100% for both. Of the channels I tuned to the picture and audio were perfect. Back to linux and it's crap again.

I did notice that I had to select what type of aerial I had and if I wanted gain set to on/off/auto.

I guess the next step is fresh install, but it'll have to wait until I get some more free time with tv to myself

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Sat Dec 06, 2014 8:58 pm

I just had a tuning failure (8:15 BBC 1 HD Winter Hill) but femon showed a low signal level at the time so I still think my issues are related to reception.
The problem you describe seems much more severe.
Try using dvb-fe-tool to put the 290e in the correct mode before its used.
Stop the backend.
Run
dvb-fe-tool –set-delsys=DVBT2
then restart the back end.
It this works the line would have to be included in the myth startup script.

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Sun Dec 07, 2014 3:00 pm

The correct syntax for using dvb-fe-tool to set the delivery system is as follows :-
dvb-fe-tool -a 102 -f 0 -d DVBT2
With the a and f params specifying the front end adaptor see dvb-fe-tool --help
According to http://www.linuxtv.org/wiki/index.php/Dvb-fe-tool dvb-fe-tool --femon provides a signal monitor but I cant get that to work.

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Sun Dec 07, 2014 8:59 pm

On the off chance some drivers are bad I built all the v4l drivers with the most git repository, nothing changed. Also the dvb-fe-tool didn't work as it was already set to dvbt2.

I did find a thread on the mailing lists that had exactly the same problem, but the user disappeared http://xkcd.com/979/

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Mon Dec 08, 2014 9:47 am

This is very strange my 290e is absolutely fine on 14.04 so it must be a reception issue.
Remember when you tested using windows the channels tuned to could have been different ie from another transmitter.
So check your tuned to the correct HD muxes for your area - although I cant see how the upgrade would effect this.
In your case SD is fine but HD very bad is that true.
If you have 100% signal, attenuate it down to about 70%.
Failing that I would do a clean install of 12.04 or 14.04.
If you dont want to trash your current system, install onto a USB stick, Myth runs well enough to test from a 16 gb one.

deadite66
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Re: PCTV 290e dvb-t2 signal problems after update

Post by deadite66 » Mon Dec 08, 2014 4:55 pm

i have 2x 290e's and don't have a problem, running 14.04 x64, kernel 3.16.7 and myth 0.27.

http://www.ukfree.tv/extras/settings have good coverage maps and transmitter power levels.

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Tue Dec 09, 2014 8:36 am

Having re-read the first post carefully I note that your troubles started with a channel scan, what version of Mythtv are you using?
I note that there was a change to the DVB-T2 scanning code.
"Add support for explicitly recognising QAM-256 with DVB-T2"
https://github.com/MythTV/mythtv/commit ... 3c12e1a359
This was commited into myth 0.27 on Nov 13th.
I have not done a re-scan since.
Why did you rescan?
If you still have a darabase backup, restore it and see if you can tune the HD channels.

jksj
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Re: PCTV 290e dvb-t2 signal problems after update

Post by jksj » Tue Dec 09, 2014 5:05 pm

Ignore the point above concerning channel scan for DVB-T2. I have just tested it using a build from Nov 19th - worked fine.

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Thu Dec 11, 2014 5:56 pm

I did the rescan to pick up the second dvb-t2 mux that got launched. I just need some free time now to mess around with it some more.

thon
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Re: PCTV 290e dvb-t2 signal problems after update

Post by thon » Fri Dec 19, 2014 11:06 pm

A fresh install of 14.04 didn't help, so I'm left with a fresh install of 12.04 which I'm currently doing, a broken tuner, or climbing on to the roof in this lovely windy weather to realign the aerial.

I did notice that the fresh install of 14.04 had trouble with dvbt signal after tuning to dvb-t2. But it could just be the wind

Edit: well something interesting has just happened, on a 12.04.4 mythbuntu install i got a tuner error in mythtv, lsusb shows
Bus 001 Device 004: ID 2013:024f Unknown (Pinnacle?)
unplugging the tuner and replugging it made it work, but it still wont tune to hd.

so to sum up:
started 12.04 (3.2) worked fine
upgrade to 14.04 broken*
fresh install 14.04 still broken*
fresh install 12.04.4 (3.11) broken*
windows 7 with pctv software works fine
*broken as in dvb-t2 picture is bad, but dvb-t is fine
Last edited by thon on Sat Dec 20, 2014 12:04 am, edited 1 time in total.

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