[mythtv-users] DVB-S2 scan fails (0.29)

Stephen Worthington stephen_agent at jsw.gen.nz
Sat Dec 23 15:09:41 UTC 2017

On Sat, 23 Dec 2017 11:02:49 +0000, you wrote:

>I'm rebuilding a standalone mythtv machine with ubuntu 16.04 LTS and mythtv
>I successfully imported the database backup from the old machine that had
>died a few months ago during a software upgrade and that I had never found
>the time to resurrect.
>I would now like to make tv reception work again. I have a Freesat HD
>(DVB-S2) setup. To be sure, in mythtv-setup I have deleted all capture
>cards and deleted all video sources. I have then remade the two capture
>cards of my TBS 6981 dual tuner, I have made an EIT video source and I'm
>now stuck at the input connections and channel scan phase.
>[DVB: /dev/dvb/adapter0/frontend0] (DVBInput) -> EIT
>scan for channels
>tv, unencrypted, video source eit, input /dev/dvb/adapter0/frontend0, scan
>type full scan (tuned)
>When I get to the "scan type" screen, I fill it up with the parameters for
>dvb-s2 from the very useful page at http://parker1.co.uk/mythtv_freesat.php
>, which has been my reference for years:
>Freq: 10847000
>Polarity: Vertical
>Symbol rate: 23000000
>Mod Sys: DVB-S2
>FEC: 2/3
>Modulation: 8PSK
>Inversion: leave at auto
>Rolloff: leave at 0.35
>Now the first glitch: a number of times, when I exit this screen, the
>settings I just entered are lost, and I can't figure out why.
>If I exit by "left arrow", then go back in with "right arrow", the settings
>I entered are still there.
>If I exit by "ESC / Save then exit", then go back in with "scan / full
>scan", then the settings I entered have disappeared, despite me having
>selected "Save then exit". Uh??? WTF?
>I then patiently re-enter the parameters, carefully exit that screen just
>with left-arrow, go down one item to "scan", press enter, nothing happens
>for about 10 seconds and then I get a SCANNING screen with "failed to find
>any channels".
>What am I doing wrong? Could it be that my reference page is obsolete and
>that these frequencies are no longer used? Well, I checked on the BBC's
>website too and finally found this
>which has essentially the same data as above:
>Astra 2E (28.2° East)
>Transponder 50
>Frequency: 10.84700 GHz
>Vertical polarisation
>Modulation: DVB-S2, 8PSK
>Symbol rate: 23.0 Mbaud
>FEC 2/3
>Transport Stream ID: 2050
>What else is the problem? And by the way, why does "save then exit" not
>save the parameters? Could there be some wrong permissions somewhere,
>either in the file system or in the database? It is a rebuilt system after
>all... I was already more than impressed that the old database backup was
>restored at all notwithstanding having upgraded myth to a newer version.

That sounds like you may need to increase the tuning timeouts.  But
take a look in your logs to see what is actually happening.  You may
want to run mythtv-setup.real with the extra logging option "-v
chanscan" for more detail.

Are you running v29, or v29+fixes?  If you are just running v29 from
the main repositories, it would be a good idea to add in the ppa and
get the latest fixes version.

More information about the mythtv-users mailing list