[linux-dvb] people watching 28.2E in the south-west of France

[Chris Moore]

Tony Grant a écrit :
> Le dimanche 24 juin 2007 à 21:04 +0200, Moore a écrit :
>
>   
>> I am in Montesquieu-Lauragais about 28 km SE of Toulouse.
>> I have a 1 m dish on a polar mount.
>> When pointing at 28.2° E the polar mount twists the whole dish by about 
>> 20° clockwise (looking at the dish from in front).
>> I get perfect reception.
>>
>> HTH.
>>
>> Where do you live ?
>>     
>
> Eauze, Gers. Thanks
>
> I can see the problem I will have to mount the dish on my motor mount
> which has the right correction. But I don't think the wall of the
> terrasse will take the weight...
>
> My dish is 80cm but I have read that someone in Pau has perfect
> reception with a 60cm
>   
I am also pretty sure that 80 cm should be adequate.
However I think you may have problems on Astra 2D channels with a 60 cm, 
particularly in bad weather conditions.
Unfortunately IMO everything worth watching is on 2D :-(

I don't think you necessarily need to twist the whole dish as a polar 
mount does.
Twisting the LNB by a similar amount should avoid cross-polarization 
problems.
(However I do seem to remember seeing some of the tiny fixed elliptical 
dishes in London mounted on the skew.)
IMHO it is better to look for a minimum on the wrong polarization rather 
than a maximum on the correct polarization.
This is probably difficult to do on digital : dish alignment was easier 
in the good old analogue days :-(

Nevertheless I am surprised you are having problems with the 
polarization as in practice I have never found it too critical.

Cheers,
Chris