Re: experiences and lessons learned with a fresh Eumetcast install for WIndows and Linux


Ernst Lobsiger
 

Andreas

Link Margins (LM) are something like:

16APSK 2/3 : LM = SNR - 9.3
  8PSK 2/3 : LM = SNR - 5.9

EUMETSAT recommends LM > = 4dB for good EUMETCast reception.
With SNR = 9.1 dB you have a negative LM for HVS-1. Unless you
have a real MODCOD filter (that sets MODCODs on the demod chip)
you cannot receive HVS-1 nor BASIC as this is disturbed by HVS-1
packets as well. If your Windows setup allows for MODCOD selection
try to set 8PSK 2/3 only (you should see a remarkable improvement).

Under GNU/Linux (apart from routers) you have limited possibilities:

1) Have a dedicated 1.25m dish with very accurate pointing to 10° East.
   Depending on your antenna position you can expect SNR up to 15dB.
2) Use a TBS5925 USB box or TBS6925 PCIe card with my patched driver
   for BASIC only. Both HW solutions deprecated, not produced anymore,
   use a first generation VCM capable chip for one transponder only.
3) Use a Technisat SkyStar 2 eXpress HD if you are lucky to find one on
   e-Bay. I recently tested this card again and Christian was able to
   get one for 20Euros that works in his 55Euro Ancalagon for BASIC only.
   With TBS drivers this makes a perfect GNU/Linux BASIC only receiver.

In the long run you cannot go with USB boxes as you need one box
per transponder the way you need one SR1 per EUMETCast transponder.
With a good SNR you can use a TBS6903 for T1+T2 with a single cable.
You can use a TBS6908 (equals 2 x TBS6903) for up to 4 transponders.
You should soon be able to use a "cheap" TBS6909X V2? for 4 EUMETCast
transponders (don't buy this card yet, latest HW changes are under way!).


Best regards
Ernst


@David
Agreed, Windows must be far easier for setting up a TelliCast receiver.
K.-P. is doing his best to make GNU/Linux TC receivers still possible.
But as you said, different distributions make this "mission impossible".
On the other hand automatic updates from Microsoft must be a nightmare.

@Peter
I use Devuan that is still systemd free and have good results. Some
scripts distributed by EUMETSAT are buggy (including the SACSrv SysV
script!) that can make installation a little bit harder. Some may also
be dependant on binutils installed (not mentionned). But once you have
a running GNU/Linux TC receiver it will work for years without updates.
You can use old surplus HW and even make DVB-Routers with PCIe cards.
I use TBS PCIe cards and have my own adapted multi transponder scripts.
I could/should publish all my latest findings, but I am 68 and time flies.


On Thu, Sep 17, 2020 at 03:09 AM, Andreas Mueller wrote:
Now for my environment the only hope would be to get a patched 5927 driver similar to the 5925 version - unfortunately this goes beyond my skills ...
@ Andreas
I tried to patch the stv0910x driver (without HW documentation!) for MODCOD selection along the lines I did it for stv090x. Unfortunately no success ..

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