[linux-dvb] Re: Tuning problem

[Lauri Pesonen <lauri.pesonen@firsthop.com>]

An update,

I tried tuning to the frequencies (below) with the TT windows software. A 
couple of times the software said that it found a signal and was not 
looking for PSI/SI tables (I'm not sure about PSI...running Linux again so 
I can't check). Then it moved to the next frequency and nothing was 
displayed on the channel list. At other times the software just complained 
about "no DVB signal". The channel frequencies below and in the software 
do not match perfectly. There are 1-2 MHz differences. Apparently my local 
cable provide uses a different frequency raster than TT thought about when 
designing the software. Thus I think that the windows software might not 
be able to tune correctly to the frequencies used by my cable provider.

Then I tried it with Linux again. I changed the QAM setting from QAM_64 to 
QAM_128 in VDR and dtv_scan. It did not work. Neither of two programs 
found any channels. 

Today I added debug printing in order to take a look at the Front End Info 
with the following results:

Jan  5 18:21:27 localhost vdr[1532]: FEINFO: minFreq = 500
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: maxFreq = 2700000
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: minSrate = 500000
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: maxSrate = 30000000
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: hwType = 0
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: hwVersion = 0
Jan  5 18:21:27 localhost vdr[1532]: FEINFO: feType = FE_QPSK

Pay special attention to the last line of the output. 

!! I HAVE A DVB-C CARD, IT SHOULD SAY FE_QAM !!

As I see it, there are two possibilities:

1. The DVB driver is broken

2. TechnoTrend gave me a very weird DVB-C card (I have no experience with 
sat stuff, but AFAIK the connectors look different then the normal antenna 
connectors)

Since I'm using the siemens_dvb-0.9-20010921 driver from Klaus' page 
(patched with the still image patch) and that same driver version works 
for others, I think that the driver is OK. Thus I'll probably have to get 
in touch with TechnoTrend on monday.

Or does someone have any other suggestions?

Just to make sure that VDR also thinks of my DVB-C card as a DVB-S card I 
added a log entry to DVB-S tuning cde which shows that VDR indeed tries to 
tune the card with DVB-S params.

I should also mention that the both of my cards, the full-featured and the 
budget card, return FE_QPSK in Front End Info queries.

-- Lauri

On Fri, Jan 04, 2002 at 10:41:53PM +0200, Lauri Pesonen wrote:
> > They should at least be able to tell you what modulation they
> > use, if they use spectrum inversion, etc.
> > Since the TT software also fails maybe they are using some kind of
> > exotic setup.
> 
> I got the following frequency list from them, so now I know what to look 
> for at least... :
> 
> Freq.		QAM	Srate	
> 283             128     5,9
> 290             128     5,9
> 297             128     5,9   
> 
> 146             128     6,9
> 154             128     6,9
> 162             64      6,9
> 170             128     6,9


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