[linux-dvb] Unwatchable channels and strange behaviour of Hauppauge Nova-T Stick (update)

José Oliver Segura primijos at gmail.com
Thu Dec 14 01:48:55 CET 2006


       Hi all,

       after a visit from my "cable guy" (the antenna guy, actually),
I still have problems with the Nova-T Stick to be able to tune/watch
some DVB-T channels. I was hoping it to be a trouble with the antenna,
but the reality is that -as the technician said- the antenna it's OK
:(

       Unfortunatelly, that was expected, since the stick works
perfectly under windows, so... after that, with some new tests, I've
found some strange behaviours that maybe can help some of you to
diagnose what can be the cause to make it work perfectly on windows
and not so perfectly on linux. I've found that:

       * There are channels that work all the time, they show a strong
signal (about 0xa000 with femon), 0 ber and 0 unc. I can start mplayer
using dvb:// , watch it almost inmediately, stop mplayer, restart it
again, and it works ok all the time. Example (from channels.conf):

Barcelona tv:514000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:256:258:30800


       * There are channels that work almost all the time. They show
also a relative good signal (0x7900). "ber" for these channels is
small (0x000000 or 0x000010) the first time I start mplayer, if I quit
and restart it, ber increases (0x00001b10) and ocasionally, I got
"unc" for those channels (at that point, it's unwatchable). Example:

SETenVEO:834000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:1401:1402:261

       * There are channels that only work randomly, and almost never.
They show up a similar signal strenght most of the time (0x7800, but
look forward in this mail, because I think this actually doesn't
matter) and, present a very weird behaviour:

         - Plug the stick, tune (mplayer) to one of these channels,
works OK (please, note the low signal; despite it, the channel appears
OK):

[root at mediacenter dvb-apps-5bfafd15aebd]# femon
FE: DiBcom 7000MA/MB/PA/PB/MC (DVBT)
status SCVYL | signal 680d | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
status SCVYL | signal 6803 | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
status SCVYL | signal 67f7 | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
status SCVYL | signal 6804 | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
status SCVYL | signal 67ed | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK
status SCVYL | signal 67fd | snr 0000 | ber 00000000 | unc 00000000 |
FE_HAS_LOCK

         - Stop mplayer, try to start it again with the same channel,
it doesn't work. Mplayer complaints about a timeout, and femon shows:

[root at mediacenter dvb-apps-5bfafd15aebd]# femon
FE: DiBcom 7000MA/MB/PA/PB/MC (DVBT)
status SC YL | signal 75a3 | snr 0000 | ber 001fffff | unc 000000c0 |
FE_HAS_LOCK
status SC YL | signal 75aa | snr 0000 | ber 001fffff | unc 00000f37 |
FE_HAS_LOCK
status SC YL | signal 75b7 | snr 0000 | ber 001fffff | unc 00000280 |
FE_HAS_LOCK
status SC YL | signal 75b8 | snr 0000 | ber 001fffff | unc 00000b3c |
FE_HAS_LOCK
status SC YL | signal 75b2 | snr 0000 | ber 001fffff | unc 00000492 |
FE_HAS_LOCK
status SC YL | signal 75be | snr 0000 | ber 001fffff | unc 00000400 |
FE_HAS_LOCK

(please, note that signal is **higher** now, but status is not SCVYL
as in the previous case, and "unc" is not zero. I supose "ber" cannot
be reliable since "status" seems to expose a problem tunning?)

              - From that time on, that channel cannot be watched (90%
of the time it doesn't tune 100%, 10% of the time it tunes but with
higher and higher "unc" and "ber") unless I unplug the stick and plug
it back again. Then, I can tune that channel again. The only operation
that -sometimes- allows me to be able to tune these problematic
channels again without unplugging the stick is by tunning it to a
"reliable" channel, watch a little bit, stop mplayer, wait some
seconds and trying to tune again the problematic channel.

       Example of problematic channel:

TVE 1:818000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_4:HIERARCHY_NONE:101:103:490


       If anybody can help me (I can help you to diagnose by doing any
tests you ask me to do) to solve this problem, I'll appreciate. I
expected everything to be an antenna problem but, as told... it's OK
:( and (the worst)...it works ok on linux.

       If somebody needs some more data, log files, etc., just let me
know. Beside that, if any of the subscribers of the list lives in
Barcelona (es-Collserola transponder info for scandvb) and has this
same stick working, I'll appreciate having some feedback about it.

       Best,
       Jose



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