[mythtv-users] DiSeq problems
mythtv at edsons.demon.nl
Fri Dec 22 11:48:53 UTC 2006
Rudy Zijlstra wrote:
> I've run out of ideas on this one. My setup: tuner card connected to
> DiSeq 2.0 switch, with the Diseq switch connected to two satelites,
> each connected with 4 LNB to the switch (its a 9/16 switch, which
> supports 2 SAT, and internally generates the tones needed to keep each
> LNB fixed).
> The STB i have connected in parrallel (setup: DiSeq 1.0 switch with 2
> LNB) works without problem and receives both Astra 19.2 and Astra 28.2
> without problem.
> I'm running MythTv 0.20-fixes (on my test system the latest SVN) and
> am noting that after installing the diseq switch i cannot tune anymore
> to the channels. I've deleted the DVB tuner and re-installed it. The
> DVB-S setting now tells the system its connected to a 2-port switch,
> and the switch it connected to 2 LNB's (universal LNB, tone and
> voltage). Mythtv-setup seems able to scan astra 19.2, but not able to
> tune most of astra 28.2. And even this is not always working, as can
> be seen in the attached log.
> Attached a log from mythtv-setup, and from mythbackend trying to tune
> (this from operational system, temporarily re-configured to support
> DiSeq switch in order to test difference between budget and full
> feature card -> same behaviour).
> Anyone have an idea how to solve this?
OK, to store for others runing into this problem.
a/ the STB was also not receiving all channels, with > 600 FTA channels
received, it took some time before i realised the STB was also missing
b/ Cause of the problems:
When using a Diseqc switch before an LNB, and using a LNB with 4
outputs, you have to be very carefull with which LNB you use.
There exist both QUAD LNB, and QUATTRO LNB. They are NOT the same.
I was using a QUAD LNB, where i needed to use a QUATTRO LNB.
QUAD LNB has 4 independent LNB into 1 device. Each output can be
indenpendently controlled by a tuner. Essentially 4 LNB into 1.
QUATTRO LNB has 4 outputs, and each is fixed on a particular setting, so
you have low-horizontal, low-vertical, high-horizontal and
high-vertical. These are intended to be used with DiseQc switches. Each
output to be connected to the correct input on the switch.
There are very few diseqc switches that can handle a QUAD LNB. There
seem to be some, but they are rare.
After exhanging the QUAD to an QUATTRO, and connecting the cables
correctly, all started working.
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