[linux-dvb] Re: cx22702 UCBLOCK problem

[Andrew de Quincey <adq_dvb@lidskialf.net>]

On Thursday 09 Sep 2004 16:37, Andrew de Quincey wrote:
> [...]
>
> > Also, that channel gets an absolutely perfect signal with a
> > TDA10045-based Nova-T.
>
> To follow this up - all transponders work fine, except for the Sky
> transponder - I get bad glitching on that. And I don't with a TDA10045.

Follow-follow-up. I see this sort of output with dvbtune:

Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=0, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=180, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=180, (S|L|C|V|SY|)
Signal=57, Verror=0, SNR=65535dB, BlockErrors=180, (S|L|C|V|SY|)
...

The signal always works ok at the start. Then the errors start. Note that 
Verror is set to 0, although occasionally it becomes non-zero. If I Ctrl-C 
dvbtune, and tune again, the signal is ok for a while, followed by errors 
again.

The time for the signal to "go bad" varies greatly - sometimes it takes about 
5 seconds, sometimes > 30. I tested the TDA10045 again, and it has no errors.

Monitoring the transport stream itself shows bursts of errors starting at 
about 20 seconds.

The parameters for the Sky transponder here are:

frequency=746000000
hp-rate=3/4
lp-rate=3/4
modulation=QAM-16