Just Sharing This LNB Changer Andrew ES 37

dreamsat

dreamsat

Specialist Contributor
My Satellite Setup
2,20m Kathrein, 3,7m Andrew, KU,KA,C,C-Ext. LNBs
My Location
germany
A view of my LNB changer. An AV comm unit is currently being worked on and will be installed in the spring.

Merry Christmas to you all!
 

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it s a kind of device i like !!!
does the ku/ka lnb are turning (for skew)?
does the same lnb move from left to right ?
 
Yes, the LNBs move from left to right. The selected one is always in focus. The Ka-band LNBs function linearly and circularly, similar to an AV communicator in the C-band. The polarizer can also be optimized for linear operation. The Ka-band LNBs are switchable between bands: Ka A to B and Ka C to D.
Skew control is of course also possible, and the entire changer can be shifted in focus towards the antenna.
 
dreamsat said:
A view of my LNB changer. An AV comm unit is currently being worked on and will be installed in the spring.

Merry Christmas to you all!
Click to expand...

Great Enthusiast work and Merry Christmas to all :Y, look forward to your spring time work.
Iv'e thought about doing a sliding rail contraption before but never bothered - you've inspired me to get it thought about again for next summertime to replace my conventional rotary setup

2.2m changer.webp
 
With a prime focus antenna, there aren't that many options. It's either a tilting mechanism or a rail. If you only have three feed rods, it gets even more complicated.
 
dreamsat said:
Yes, the LNBs move from left to right. The selected one is always in focus. The Ka-band LNBs function linearly and circularly, similar to an AV communicator in the C-band. The polarizer can also be optimized for linear operation. The Ka-band LNBs are switchable between bands: Ka A to B and Ka C to D.
Skew control is of course also possible, and the entire changer can be shifted in focus towards the antenna.
Click to expand...

I had thought to ask a while back but forgot, but how does the Andrew reflector perform on Ka band against the theoretical 3.7m area ?
 
Congratulations on the setup.
Some time ago I saw something similar invented by a great German enthusiast who immigrated to Brazil. He built himself an 8-meter disc. He also had a similar setup, though obviously more rudimentary, considering it's from 20 years ago.
 
dreamsat said:
With a prime focus antenna, there aren't that many options. It's either a tilting mechanism or a rail. If you only have three feed rods, it gets even more complicated.
Click to expand...

OT ... I took the potential stress and reflector warping damage off the three original lnb support arms and constructed a new lnb / changer support system that's bolted through the reflector skin and onto the 50mm thick walled back ring of the reflector - so far, no problems.
Tinkering and refining never stops though :)


2.2mtr changer...reduced.webp
 
@dreamsat very impressive job !
I can't imagine hours of studying a such project ...
How have you motorized your 3.7m dish ? With "standard" actuator ?
 
anto@ said:
Congratulations on the setup.
Some time ago I saw something similar invented by a great German enthusiast who immigrated to Brazil. He built himself an 8-meter disc. He also had a similar setup, though obviously more rudimentary, considering it's from 20 years ago.
Click to expand...
German engineering never disappoints! :Y:)
Schumacher
 
dreamsat said:
A view of my LNB changer. An AV comm unit is currently being worked on and will be installed in the spring.

Merry Christmas to you all!
Click to expand...
Impressive
 
Good work done will try and see if that will work on my 3m prime focus dish,can u please give the names of items used or the complete diagram. Merry Christmas and a happy new year
 
There are no drawings, and most of it was designed from memory. Some parts were salvaged from scrap, and many small details were simply tested until they worked. The drive shaft for the height adjustment mechanism is 40 mm thick and was in a old CNC machine. It is mounted in a gearbox with a 1:70 reduction ratio, which drives a geared motor with a 1:80 reduction ratio.
 
Here are a few more of the few pictures I took. The spindle runs through a spindle nut welded into a heavy stainless steel sleeve. The whole assembly is mounted on a 1:70 gearbox and protected from the elements by two interlocking stainless steel sleeves. A geared motor moves the entire assembly very smoothly. Limit switches are installed for safety, and control electronics are also needed to manage the movement. In my case, it's an H-bridge that also supports tip operation. This allows for first-class positioning.
 

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anto@ said:
Congratulations on the setup.
Some time ago I saw something similar invented by a great German enthusiast who immigrated to Brazil. He built himself an 8-meter disc. He also had a similar setup, though obviously more rudimentary, considering it's from 20 years ago.
Click to expand...
Sadly he passed away some years ago.
 
dreamsat said:
A view of my LNB changer. An AV comm unit is currently being worked on and will be installed in the spring.

Merry Christmas to you all!
Click to expand...

Fantastic job! Really congratulation!
 
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