Mnyash
JF-Expert Member
- Feb 9, 2013
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What about the LNB arms, are their length not extended accordingly to cater for the new focal point?
African Satellite World and Sat Gear
African Satellite World and Sat Gear
- Thread starter kungu1
- Start date
freq
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- Sep 11, 2017
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Focal point remains the same.
A pf dish is basically a section of a sphere and the focal point is it's center.. if you complete the absent parts of the sphere which is essentially what is done when building extensions the centre/ focal point doesn't change and the arms remain.
GITHS
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- Jul 29, 2017
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Thanks again
Which receiver are you using
Mnyash
JF-Expert Member
- Feb 9, 2013
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Ohhh alright, I now get you. If you continue adding the missing parts you will basically get a ball. Thank you.
GIDEN
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- Apr 19, 2015
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The quality of work is on point.
freq
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Yes a smooth Ball but the centre remains
GIDEN
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Not true. For the lnb to fully illuminate /"see" the whole reflector you should adjust the focal distance/length.
An unstable tp can stabilize by extending the plate, if the extension is perfectly done you should get/calculate new focal length as even the depth changes.
freq
JF-Expert Member
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Haha... Imagine you get your new focal point and build new arms .
BUT remember radio waves reflected by the original sections of the dish (Which you're extending) will converge at the Original focal point... Where they were meant to converge
AND you build a new focal point for your extended parts..
YOU end up with a dish with TWO focal points.. one below the other the a original Focal point and a new focal point for your extensions.
🤩😀😀 powerful dish.
GIDEN
JF-Expert Member
- Apr 19, 2015
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This has been my WIP for sometime. I will adjust the focal length if i get time. The dish performs very slightly better than a 6ft.
1. The additional weight alters the shape.
2. The dish is very deep as the initial curvature shapes the curve of new petals.
3. A very deep dish cannot produce a sharp beam wave so it may have a low efficiency.
4. A deep dish is not good for Ku band.
1. The additional weight alters the shape.
2. The dish is very deep as the initial curvature shapes the curve of new petals.
3. A very deep dish cannot produce a sharp beam wave so it may have a low efficiency.
4. A deep dish is not good for Ku band.
GIDEN
JF-Expert Member
- Apr 19, 2015
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True it has two focuses.
freq
JF-Expert Member
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Ckeck your set up.. 2.4m OK
freq
JF-Expert Member
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A little problem you have over there is each and every extension seems to have their own curvature profile and thus collecting reflections at their own little Focal points around the main focal point..
You may improve performance by creating a single continuous extension curvature around the original rim albeit in parts
Mnyash
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- Feb 9, 2013
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True!
Aaaaarrghhh
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- Nov 2, 2017
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Nikama Jeshi wameenda ki Arq ...... sad.
X-PONDER
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- Oct 19, 2014
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Starsat 2000 extreme HD
freq
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It said that ARQ never went missing... They just reduced the signal strength to a level you'd need a 12ft to receive it..