[mythtv-users] Strong signal, ugly artifacts...

[Robert McNamara]

On Thu, Jun 4, 2009 at 2:53 PM, Andrea Giuliano <sarkiaponius at alice.it>wrote:

>
> Robert McNamara wrote:
>
>>
>>
>> On Thu, Jun 4, 2009 at 1:51 PM, Andrea Giuliano <sarkiaponius at alice.it<mailto:
>> sarkiaponius at alice.it>> wrote:
>>
>>    I'm seeing horrible artifacts in my DVB-S recordings, even though
>>    MythTV says the signal strength is 99%
>>
>>
>> Signal strength isn't what you think it is.  Signal strength is the
>> strength of the electrical signal between the card and the LNB, *not* an
>> indication of quality of the signal.  More helpful for this is SNR (Signal
>> to Noise Ratio) and Bit Error.  Low SNR or high bit error means bad quality
>> signal.  Repoint the dish.
>>
>>
> Dear Robert,


> thanks for your kind answer. Can you please give me reference values for
> SNR and Bit Error? I got 4.8 dB and 2000-3000 for them, depending on the
> channels. Actually, SNR seems to be constant, I mean it's alway 4.8 dB,
> while BE changes instead.


> Also, my dish works perfectly fine with my stand alone decoder (I have two
> cables from one dish), so I guess it's not its fault.


> Best regards.


(Fixed top posting)

Hi Andrea,

Ideally, the BER should be 0 or extremely close to 0.  Different tuner
devices have different signal sensitivities and different decoders are more
or less sensitive to errors in the stream.  Both are likely problems for
you.  You will almost definitely need to point your dish more accurately.
 You can also check all your cable termination, the cables themselves, and
any power inserters for the LNB.

Robert
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mythtv.org/pipermail/mythtv-users/attachments/20090604/b1316a18/attachment.htm>