UK spot beam variances in Spain ( and elsewhere )

<THOR>

<THOR>

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Guadalajara, Spain
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10906 V 22000 - 6.0dB
11306 H 22000 - 3,9dB
11306 V 22000 - 3,9dB
11386 V 29500 - 5,4dB
11426 V 27500 - 5,3dB
12129 V 27500 - 3,7dB

Triax TD88 with Inverto black ultra
I have to replace the cable these days, so I could get better results.
 
W

WHATAGOAL1

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what causes the time variances?
 
W

WHATAGOAL1

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"12 608 H is very strange. Sometimes 9,9 dB and other times only 4,5 dB"

why should this be?, is it just down to the weather?
 
A

Archive4

Guest
"12 608 H is very strange. Sometimes 9,9 dB and other times only 4,5 dB"

why should this be?, is it just down to the weather?
Are you talking about your own readings taken in Leeds? You should not have that low a reading, other than in heavy rain / storm conditions, which don´t happen very often in those parts:-rofl2
 
W

WHATAGOAL1

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its not my reading, its just what someone reported, and I wondered what caused the difference.
It seems thar from yoour reply, the differences are weather related.
 
skomedal

skomedal

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thule
Probably Astra 2 UK spot beam " Fringe reception sat. wobble "

Occurs for me in ( off topic ) central southern norway :D

Regards
 
A

Archive4

Guest
its not my reading, its just what someone reported, and I wondered what caused the difference.
It seems thar from yoour reply, the differences are weather related.
I have just gone through the thread and cannot find a mention of 12608 H at all.
Do I need new glasses?
 
timo_w2s

timo_w2s

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what causes the time variances?
The satellites in geostationary orbit are kept there with the help of thrusters that keep the satellite in the right location. They tend to do a little figure of 8 dance over a 24 hour period or so. The exact location of the satellite varies by a few fractions of a degree as it moves back and forth. Normally this isn't an issue for small dishes but ground stations with very large dishes (10m+) need to keep a much more accurate track of the satellite due to beam width of the dish (the bigger the dish the smaller the beamwidth) plus as you go to the very edges of the satellite footprint you will see more obvious variations in signal strength even with smaller dishes as the satellite moves about and goes in and out of the footprint. If you are in the middle of the footprint (like in the UK) you won't see this effect.

At least that's how I understand it, but I'm not a rocket scientist so I could be wrong. ;)
 
skomedal

skomedal

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The satellites in geostationary orbit are kept there with the help of thrusters that keep the satellite in the right location. They tend to do a little figure of 8 dance over a 24 hour period or so. The exact location of the satellite varies by a few fractions of a degree as it moves back and forth. Normally this isn't an issue for small dishes but ground stations with very large dishes (10m+) need to keep a much more accurate track of the satellite due to beam width of the dish (the bigger the dish the smaller the beamwidth) plus as you go to the very edges of the satellite footprint you will see more obvious variations in signal strength even with smaller dishes as the satellite moves about and goes in and out of the footprint. If you are in the middle of the footprint (like in the UK) you won't see this effect.

At least that's how I understand it, but I'm not a rocket scientist so I could be wrong. ;)

spot on1.png

Regards
 
Lazarus

Lazarus

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^^^^^
Have you lost weight? You're looking well.
 
Lazarus

Lazarus

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I suppose you want a apology (sic)? ;)
 
Huevos

Huevos

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A satellite does not move in a figure of 8. That is an illusion.

Reason 12129 is lower signal is because it is higher frequency. As the frequency goes up the nulls move slightly closer to the centre of the beam.

Lower Costa Blanca the signal is severely attenuated. In South Valencia it is just the same as any other 2E transponder. Where I am it is half way between the two.
 
PaulR

PaulR

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Huevos

Huevos

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If you got the inclinded orbit and tilted it further so instead of being over the equator the satellite went over the poles... the period would would still be 23 hours 56 minutes, but what pattern wouldit appear to draw on the earth's surface which is spinning inside its orbit? The figure of 8 is just something perceived by the viewer, not something the satellite actually does.
 
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