What size dish needed in Portugal for Astra2D
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all UK channels on Astra2D All Day, all Night, all Year with no
pixelation. TIA
Java Jive
http://www.ses-astra.com/business/uk/satellite-fleet/index.php
If you also want general advice and a calculator for installation,
take a look at my section on satellite tv:
http://tinyurl.com/6fpbyy
... standing in for ...
http://www.macfh.co.uk/JavaJive/AudioVisualTV/SatelliteTV/SatelliteTV.html
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Thanks but the Astra2D link did not help, it shows no footprint over
Spain (presumably to keep BBC license fee payers happy), when of
course we all know there is one, albeit weak. As for setting up
dishes, I have done a few, thanks anyway.
Miles Collins
> Advice please on what size dish is needed in Portugal for reception of
> all UK channels on Astra2D All Day, all Night, all Year with no
> pixelation. TIA
Map: http://www.astra2d.com/iberia2d.htm
Reports: http://www.astra2d.com/portugal.htm
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Java Jive
that, allowing for the fact that the beam will be hitting the Earth's
surface at a slight slant, the 'isosize' lines don't radiate outwards
more or less uniformly in an elliptical pattern from the centre of
coverage.
On Fri, 03 Jul 2009 22:51:57 +0200, Miles Collins
<not-fo...@zybrkat.org> wrote:
>
> Map: http://www.astra2d.com/iberia2d.htm
Miles Collins
> I wonder how trustworthy that map is? Seems rather strange to me
> that, allowing for the fact that the beam will be hitting the Earth's
> surface at a slight slant, the 'isosize' lines don't radiate outwards
> more or less uniformly in an elliptical pattern from the centre of
> coverage.
>
Astra 2D reception is very weird, once you get out of the designated
reception area.
e.g. Here in north Germany, my reception of the horizontal transponders
is much weaker than the vertical ones,
whereas reception reports from Sweden and Poland claim exactly opposite.
A long time "member" of this group from Norway (whose name has
unfortunately slipped my mind, maybe someone remebers?) posted diagrams
of satellite antennae diagrams explaining these effects a few years back.
Of course as I understand it, the map I linked to is based on actual
reception reports, rather than theoretical coverage.
Java Jive
<not-fo...@zybrkat.org> wrote:
> * Java Jive:
> > I wonder how trustworthy that map is? Seems rather strange to me
> > that, allowing for the fact that the beam will be hitting the Earth's
> > surface at a slight slant, the 'isosize' lines don't radiate outwards
> > more or less uniformly in an elliptical pattern from the centre of
> > coverage.
>
> Astra 2D reception is very weird, once you get out of the designated
> reception area.
>
> e.g. Here in north Germany, my reception of the horizontal transponders
> is much weaker than the vertical ones,
> whereas reception reports from Sweden and Poland claim exactly opposite.
That is a little weird. Maybe the horizontal & vertical transponders
are focused slightly differently, or perhaps the Astra satellites'
famous pre-skew of +7.5 degrees affects the polarisations differently,
though I can't see why it should, as long as the LNB has the correct
tilt.
> A long time "member" of this group from Norway (whose name has
> unfortunately slipped my mind, maybe someone remebers?) posted diagrams
> of satellite antennae diagrams explaining these effects a few years back.
Don't recall that, so can't help.
> Of course as I understand it, the map I linked to is based on actual
> reception reports, rather than theoretical coverage.
Ah! That probably explains it then ... it's probably a comparatively
small sample group, and some users will have set up a smaller dish
well, others a larger one less well, to report adequate reception.
Miles Collins
> On Sat, 04 Jul 2009 00:42:27 +0200, Miles Collins:
>> Astra 2D reception is very weird, once you get out of the designated
>> reception area.
>>
>> e.g. Here in north Germany, my reception of the horizontal transponders
>> is much weaker than the vertical ones,
>> whereas reception reports from Sweden and Poland claim exactly opposite.
>
> That is a little weird. Maybe the horizontal & vertical transponders
> are focused slightly differently, or perhaps the Astra satellites'
> famous pre-skew of +7.5 degrees affects the polarisations differently,
> though I can't see why it should, as long as the LNB has the correct
> tilt.
There certainly is a real difference here, even if you eliminate the
inherent preference of one polarity modern LNBs have, by manually
rotating the LNB.instead of electrically switching V/H for measurement
purposes.
Where I am, it works out to H having about 2.5 dB less C/N on average
than V, if I remember correctly
I recall Jim from Gibraltar remarking on the horizontal transponders
being (about 3dB) weaker than the vertical ones where he is also.
Am I right that no such effect is measurable in the UK?
Java Jive
to tinker with a few things, but, for one thing, mine's a rotor system
which is currently working well, so I don't want to risk ruining the
setup on the fairly slim chance of improving the alignment further;
for another, my dish is above where my neighbour parks her car, so I
have to make special arrangements to get access with the ladders; and
finally it's right at the very limit of their reach, and nowadays of
my strength in getting them up there.
On Sat, 04 Jul 2009 01:38:21 +0200, Miles Collins
<not-fo...@zybrkat.org> wrote:
>
> There certainly is a real difference here, even if you eliminate the
> inherent preference of one polarity modern LNBs have, by manually
> rotating the LNB.instead of electrically switching V/H for measurement
> purposes.
> Where I am, it works out to H having about 2.5 dB less C/N on average
> than V, if I remember correctly
>
> I recall Jim from Gibraltar remarking on the horizontal transponders
> being (about 3dB) weaker than the vertical ones where he is also.
>
> Am I right that no such effect is measurable in the UK?
======================================
Jim Watt
<not-fo...@zybrkat.org> wrote:
>I recall Jim from Gibraltar remarking on the horizontal transponders
>being (about 3dB) weaker than the vertical ones where he is also.
That is in the design of the spacecraft rather than any
anomaly in receiving.
--
Jim Watt
http://www.gibnet.com
Miles Collins
> On Sat, 04 Jul 2009 01:38:21 +0200, Miles Collins
> <not-fo...@zybrkat.org> wrote:
>
>> I recall Jim from Gibraltar remarking on the horizontal transponders
>> being (about 3dB) weaker than the vertical ones where he is also.
>
> That is in the design of the spacecraft rather than any
> anomaly in receiving.
Where did you get that information from?
Jim Watt
<not-fo...@zybrkat.org> wrote:
>* Jim Watt:
>> On Sat, 04 Jul 2009 01:38:21 +0200, Miles Collins
>> <not-fo...@zybrkat.org> wrote:
>>
>>> I recall Jim from Gibraltar remarking on the horizontal transponders
>>> being (about 3dB) weaker than the vertical ones where he is also.
>>
>> That is in the design of the spacecraft rather than any
>> anomaly in receiving.
>
>Where did you get that information from?
I had a specification of the satellite rf section
can't find it now. Its a Boeing 376HP
Miles Collins
Thanks for looking.
If anyone could point me to a document noting a 3dB difference between H
& V transponding by design on Hughes/Boeing 376HP, especially Astra2D.
I'd be glad.
All the transponders are given as 16x39W (for 2D) or 20x30W (for 3A).
Nothing about polarisation losses
One would think such a marked difference (3dB) would show up in coverage
maps.
Especially as it's not the only HS-376HP
Jim Watt
<not-fo...@zybrkat.org> wrote:
True, but I did see it on a document from the Astra site that is
no longer there which listed all the transponder frequencies,
it was at the time that Iceland TV was on the bird.
There was also a significant H/V difference observed here.