This is a mobile optimized page that loads fast, if you want to load the real page, click this text.

Using microwave communications dish for Ku?

Inno

SatelliteGuys Pro
Original poster
Aug 13, 2006
1,596
5
NW Ontario, Canada
I have obtained (through legitimate means) an approximately 3.5' Andrew microwave antenna which used to reside on a tower to provide point to point communications for a remote community. It still has the feedhorn in tact although it used a waveguide to feed the signal from the equipment in the office to the antenna. I presume I already know the answer to this, but thought it best to ask anyway...Would the focal distance be the same for any LNB I place on it as the original feed? I figure it should be so that makes my work a little easier when it comes to fabricating a mount for the LNB.
 
Not quite like that, but similar. I believe this one had a "radome" on it prior to being disassembled. I will post some pictures when I get to it. Just had some time to kill at work and figured I'd pose the question. It's getting to that time of year when I think about thinking about moving indoors and what needs to be done before that happens.
 
Last time I checked, that antenna does not have a downconverter in the feedhorn like an LNBF and requires either rectangular or elliptical waveguide to bring the signal into the building. That feedhorn you see in that photo is a rectangular feedhorn that is built for a specific frequency range and may have a tunable section or what is called "dent tuned". I suppose you could modify the feed system so that you could mount a feed support (buttonhook or struts) to accomodate a LNBF. Also, when you remove the existing feed system, you'll need to put a center plate over the hole in the center of the dish.
 
Correct that there would be no downconverter etc. I had planned to fabricate a mount for a LNBF.
 

Attachments

  • 20200804_202149.jpg
    221.6 KB · Views: 190
Reactions: olliec420
Looks like that antenna may have been used for 18 GHz. But I'm guessing by the way the feed looks. Anyway, if you fabricate a support it should work for Ku. f/d and focal length can be calculated if you don't have the antenna specs.
 
Remember to chose the correct LNBF to match the reflector's FD ratio. If .5 or higher, use a regular LNBF. If .3/.4 use a prime focus type LNBF. Using the wrong type LNBF will either under illuminate or overshoot the reflector surface.
 
Reactions: raydio and Inno
You must log in or register to reply here.

Similar threads

C
Need recommendations for Ku Dish & Actuator
Replies
3
Views
688
comfortably_numb
Best 2 Ku Band Sats for one fixed Ku dish?
Replies
15
Views
2K
Hyper Casey
Ku 125W
Replies
1
Views
623
MattFL
M
New Low-cost Ku Motors & 1.2-metre Dishes
Replies
4
Views
604
cyberham
M
Ku dish sidecar
Replies
2
Views
1K
iBoston
Menu
Log in
Register