Yes, without subreflector, this dish is "pure" prime-focus dish. But, for such size of dish side-lobes and X-pol are considerable factors. For example, if dish is pointed to satellite A, with side-lobe it will also pick up signals from satellite B, which can be 2* apart. That is one of the reasons subreflectors are used (Gregorian and Cassegrain systems).
Andrews 4,6m
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Have installed 8 heaters to lower part of the dish. They consume a lot of energy when operated, so, I doubt I will turn them on. But it is better to keep them on the dish instead of them making a mess in the garage 
Also attached subreflector. Will use original waveguide as a feedarm where LNB be installed instead of C-band feedhorn.
Also attached subreflector. Will use original waveguide as a feedarm where LNB be installed instead of C-band feedhorn.
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Made this tunable device. Now I can change position of the LNB closer/further from the SUB and also Skew without going in front of the dish and obstructing signal. Later I might conciser to make LNB skewing mechanism inside the drum.
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There you are. LNB is placed in such a way that its Phase center co-located with SUB's secondary Focal point. And I can change LNB's skew from the back of the dish as you can see on the second picture in post #64.
That is great!!!
Are you pulling anything in that no one else does or cant see?
If you removed the sub reflector would you get bad bleed over from other satellites?
Are you pulling anything in that no one else does or cant see?
If you removed the sub reflector would you get bad bleed over from other satellites?
O, yes, I do. I did not hear that somebody in the region can receive signals from 28,5*E spot-beam.
I initially installed LNB without the SUB
, but it was not so convenient to do adjustments when you are always between antenna and satellite and it was pretty high above the ground. Side-lobes were huge. According to theory, Gregory systems performing up to 10% better than simple ones, but I can not clearly prove it. And Gregory also better eliminates effects of X-pol..... this I also can not prove.
No, it is still fixed and pointed to 28,5*E, as I did not install and powered motors. However, I lost all channels from UK beam because of the snow. Yes, antenna has integrated heaters, but I did not connected them yet. But I do not care, I do not need this antenna for watching TV, it is just for fun.
Add: No, I did not try C-band yet
Add: No, I did not try C-band yet
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Surely, the snow must have melted away by now, even without heaters.
Are you getting any 28.2/3/5 signal?
Some time ago I've made new feedhorn for Inverto Black Ultra. Getting good reception results with it. 
I know, it is not really X-Mas time yet, but I've installed same light-decoration to the the dish today.
I know, it is not really X-Mas time yet, but I've installed same light-decoration to the the dish today.
Nice feedhorn adaptation! Kind of looks like a feed horn I made for 10GHz, just used an old tin flashlight body and made a cone like that instead of a scaler. Worked not too bad but lots of room for improvment (at least in my RF engineering!)
Friend of mine, after seeing my feedhorn, said that I was probably drunk when I made it 
. But, in reality, this shape of the feedhorn was designed this way. Calculations and drawing, specific to my antenna, were made by another friend of mine. There are some more pictures of the process. 
Couple of days ago added more lights to the site
. But, in reality, this shape of the feedhorn was designed this way. Calculations and drawing, specific to my antenna, were made by another friend of mine. There are some more pictures of the process. Couple of days ago added more lights to the site
everyone likes fancy dishes for the Christmas Holidays
I also have an Andrew dish. It is a 3-meter PFA. The name of the town Bekescsaba. It also looks at the 28.2 degree UK beam.
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