[linux-dvb] Freecom DVB-T USB stick - no signal

Simon Blandford simon at bkinfo.net
Tue Apr 18 20:54:37 CEST 2006


Hi Patrick,

Changing the frequency from 505833333 to 506000000 fixed it.

Thanks very much for you help :-)

Simon

Patrick Boettcher wrote:
> Hi,
>
> On Mon, 17 Apr 2006, Simon Blandford wrote:
>> Here is the output from tzap...
>>
>>   [simon at simon ~]$ tzap "BBC NEWS 24"
>>   using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
>>   reading channels from file '/home/simon/.tzap/channels.conf'
>>   tuning to 505833333 Hz
>>   video pid 0x0280, audio pid 0x0281
>>   status 20 | signal ffff | snr ffff | ber 00000000 | unc 00000000 |
>>   status 20 | signal ffff | snr ffff | ber 00000000 | unc 00000000 |
>>   status 20 | signal ffff | snr ffff | ber 00000000 | unc 00000000 |
>>   status 20 | signal ffff | snr ffff | ber 00000000 | unc 00000000 |
>
> The mechanism inside the firmware of your device is not getting along 
> with "offset frequencies" as they can be found in any of the uk-files 
> for linux-dvb.
>
> I don't know why the used offset is taken into consideration in the 
> tuning files, IMHO and afaik for DVB-T always the center-frequency 
> should be used and afaik all recent dvb-t demodulators are able to 
> compensate "large" carrier offsets (up to 300 kHz or more). OTOH, of 
> course the problem here lies in the driver/firmware.
>
> To cut things shorter: Can you try to tune to 506 MHz instead of 
> 505.833 ?
>
>> Notice the unfeasible signal strength. When I scan Crystal Palace on 
>> Kaffeine it momentarily shows 100% signal and 100% s/n but finds 
>> nothing.
>
> Please try to ignore the signal strength and SNR, they are running 
> crazy when you don't have any lock.
>
>> Not sure which one of those should equate to video0 and audio0. Maybe 
>> that is where the problem lies?
>
> No, audio and video is just for device with MPEG2-decoder onboard.
>
> HTH,
> Patrick.
>
> -- 
>   Mail: patrick.boettcher at desy.de
>   WWW:  http://www.wi-bw.tfh-wildau.de/~pboettch/




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