[linux-dvb] Lifeview LR306 clone does not receive ch 7. SOLVED (partly)

Hartmut Hackmann hartmut.hackmann at t-online.de
Mon Sep 18 23:41:27 CEST 2006


Hi, all

Peter D. wrote:
> On Monday 18 September 2006 15:03, Peter D. wrote:
> 
>>On Sunday 17 September 2006 18:14, Lincoln Dale wrote:
>>
>>>>>>How do you determine what the correct center frequency is?
>>>>>>Trial and error edits to
>>>>>>/etc/dvb/channels.conf-dvbt-australia?  Or do I just wait
>>>>>>until the driver evolves to the standard of the driver for
>>>>>>the Kworld with its cx8800?
>>>>>
>>>>>Try and error or search for appropriate information.
>>>>>I will change the locking algorithm some time. But this is a
>>>>>difficult change and definitely not be there within few days.
>>>>
>>>>  Well I'm bemused by this. I have had the same card in my
>>>>desktop box (with no other pci card in it) and I had perfect
>>>>service on all 5 channels (working off the same frequencies as
>>>>Peter D). But today I pulled it out of that machine and stuck
>>>>it in my mythbox (with a Visionplus branded Twinhan card
>>>>(dvb-bt8xx) and a Kworld DVB-T card (using cx88-dvb)) and I am
>>>>now
>>>
>>>FYI, have 3 DVB-T cards here; a VisionPlus HDTV (Twinham
>>>dvb-bt8xx w/ mt352 frontend), OEM rev of DViCO FusionHDTV DVB
>>>Plus (cx88 w/ mt352 frontend) and a AVermedia AverTV DVB-T (cx88
>>>w/ dst frontend).
>>>
>>>i am also in Melbourne SE suburbs like Peter.  am running dvb
>>>tip-of-tree as of 6 September.
>>
>>I've failed with a tip more recent than that.
>>
>>
>>>i have no problems tuning channel 7
>>>(or any other channel) on all 3 DVB-T cards using frequencies as
>>>per frequences on dba website (http://www.dba.org.au/)
>>
>>Interesting.  My out-of-the-box configuration does not agree with
>>what is listed at http://www.dba.org.au/index.asp?sectionID=120 
>>You might have been lucky in that your particular hardware and
>>drivers were smart enough to correct a mis-configuration.  Or maybe
>>you system is configured correctly and mine is not.  I will
>>experiment.
>>
>>
>>>as far as i can tell, there is nothing wrong with the dvb tree or
>>>drivers. i'd suggest you check your cabling & have a look at your
>>>antenna.
>>
>>I am using one external antenna.  I think that Philip is doing the
>>same.  Signal strength seems quite good here.  Kaffeine is
>>reporting signal strength of about 94% and snr or about 80%.
> 
> 
> Changing the configuration for channel seven from "hierarchy: NONE" to 
> "hierarchy: AUTO" and "Guard interval: 1/8" to "Guard interval: 1/16" 
> allows me to get standard definition channel 7, but not HD or the 
> guide.  More experimentation is necessary.  

No experiments necessary, see below.
> 
> I can only assume that;
> A) the out-of-the-box configuration on Mandriva 2006 is wrong
> B) the driver is smart enough to correct for mis-configuration
> C) some interaction of the Kworld and MSI clobbers the 
> auto-configuration capabilities of the MSI driver.
> 
> Perhaps something somewhere discovers that auto-configuration is 
> already done (or does not need to be done) once and does not try a 
> second time?  I am just guessing here.  
> 
Aha! This is known, an improperly specified GI makes the channel
decoder unable to lock!
I mentioned this before: there can be wrong parameters in the
config files, i had this here in Hamburg too.
Some channel decoders resp. their drivers ignore them and this
is what you see: The files work with some decoders though they still
are broken.
Especially with recent firmware of the tda10046, i recommend to set
all pararameters except the bandwidth to AUTO. This avoids such
problems.

Best regards
   Hartmut



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