[linux-dvb] Dvico dual digital express - Poor tuner

Alex Ferrara alex at receptiveit.com.au
Fri Sep 26 00:19:36 CEST 2008


On 21/09/2008, at 8:41 PM, stev391 at email.com wrote:

>> On Sun, Sep 21, 2008 at 3:35 PM, Alex Ferrara <alex at receptiveit.com.au 
>> > wrote:
>>> I am currently seeing inconsistent performance with the dvico dual
>>> digital express. Some channels tune just fine, and others have the
>>> impression of a very low signal strength.
>>
>> I have the same card in regional Australia, i had a similar problem
>> problem, its working fine now though.
>>
>> One of my issue was that i had not scanned the channels properly, did
>> you generate your initial-tuning-data yourself and use scan to
>> generate the channels.conf, or use somebody elses initial-tuning-data
>> ?
>>
>> It could be that the frequency in your channels.conf isnt accurate
>> enough, from what ive experienced if you set the frequency in the
>> channels.conf to be the center frequency of channel + 125kHz you
>> should be ok.
>>
>> Also, there is an app called femon from dvb-apps package which will
>> display the signal strength of the currently tunned channel, i just
>> started that going and moved my indoor digital antenna around till i
>> got max strength.
>>
>>
>> Glenn
>
> Alex,
>
> Does this also happen in windows?
> If so another possible solution is to either turn down your  
> distribution amplifier or install attenuators on the RF input into  
> the card.
> In my mates setup I had to install a 12db attenuator inline to  
> reduce the signal enough to within the cards dynamic range (An  
> analogy of this is if you are at a rock concert next to the speakers  
> it sounds sh!t due to the high volume however if you move away or  
> muffle the sound slightly it will sound a lot better).
> His older TV cards needed this higher strength signal to operate, if  
> it didn't I would have just gotten rid of his distribution amplifier.
>
> I hope this helps.
> (I have set up a total of 5 of these cards in linux so far and this  
> has been the only issue with the current set of drivers. [Location  
> is Melbourne]).
>
> Stephen.
>
>
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I have had some time to test this fully. Using "dirty" Windows Vista I  
am able to tune all channels with perfect quality. On the same  
computer, with nothing changes except for the OS, I can tune most  
channels and only watch some. I am using Mythbuntu 8.04.1 with the  
current v4l-dvb mercurial drivers and the extracted firmware using the  
perl script in the kernel documentation directory. Kernel is 2.6.24  
incidentally.

There must be something going on in the driver or the firmware is not  
quite right. One of my friends in Canberra also has one of these dual  
express cards, and he is having very similar issues to me.

I also tested a Dvico Dual Digital 4 PCI card, and found that it  
worked perfectly. I believe mine is a v2 card, but I am not 100% sure  
on that one.

Regards
Alex Ferrara

Director
Receptive IT Solutions

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