[linux-dvb] Re: Cinergy 1200 DVB-T TDA10046H / auto mode causes problems

[wolfgang@leila.ping.de (Wolfgang Wegner)]

Hi,

I do not know this card, but in general the TDA10046 works quite
well (even) in auto mode. Lock time below 1s is what I would call
normal.

The BER values that can be read from the demodulator are quite
"jumpy", but if you take an average of some samples, it works quite
well. The SNR seems to be quite reliable, in a range of around
+/- 2dB from the value "offered" by a measurement transmitter (R&S SFQ)
with a sufficiently strong signal.
(Maybe even better, did not document that measurement)

However, depending on how the board is designed and which frontend
module is used, the power supply can be a problem. The Philips TU1216
seems to be quite immune against noisy power supply, while some Alps
module (do not remember the exact type) with the TDA10046 had to get
a _real_ stable and filtered +5V for the RF part.
I think there was such a problem with the old DVB-S cards, wasn't it?
But then there should be also problems with the windows software,
such as bad sensitivity or low SNR.

In case this really is a problem it also depends on the algorithm
used for locking; is the lock algorithm currently started only once,
or periodically? Give the demod enough time before retrying, or it
will never lock...

Regards,
Wolfgang