[mythtv-users] Diseqc problem with SG2100 rotor and MythTV

R. G. Newbury newbury at mandamus.org
Wed Jun 6 14:21:19 UTC 2007

Gert-Jan de Boer wrote:
> Hi,
> I'm installing an Ubuntu based HTPC setup with the following components:
> - Skystar2 DVB-S card
> - Diseqc 1.3 Rotor (Moteck SG2100)
> - MythTV SVN (rev. 13582)
> When I'm tuning MythTV to a satellite position it is always about 2
> degrees off to the left. When tuning to 19.2E the rotor turns to around
> 17E. Tuning to 0 results in an position around 2W.
> Tuning the rotor manually gives great signal with mplayer.
> I use the following program to tune manually:
> http://www.verbraak.org/wiki/index.php/Goto_X_program
> I think there is a problem in tuning the rotor in current MythTV SVN. 
> Does anyone have an idea how to fix the Diseqc in MythTV? My wife would
> like to be able to watch TV without using the mplayer command line ;-)

I have never dealt with a rotor setup, but this looks like a simple 
failure of calibration between where the antenna points and where Myth 
(or the intermediate controller) thinks it is pointing.

If you physically pointed the antenna 2 degrees west without moving the 
rotor base the problem would be solved (for myth).

You don't say whether the mplayer command line adjustment has or does 
not have this error. If it does not have the error (you call for 19 and 
get 19) then I would guess that there is a (hidden) and improperly set 
calibration setting. There is a field in diseqc_tree named 'ordinal' 
which is an unsigned tinyint(3)...which is just the right size for a 
0-360 number. I have no idea what a row in that table actually does, but 
a review of the table may explain things and may show where you can 
adjust the setting.

Just guessing as no-one else stepped in.


              R. Geoffrey Newbury			

        Helping with the HTTP issue
<a href="http://www.w3.org/Protocols/">HTTP</a>

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