Reception without a dish - just the LNB

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Mateosat

Active SatelliteGuys Member
Original poster
Mar 24, 2010
24
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Caribbean
Let's assume you're located within a really strong area of a footprint and the weather is superb. Would it be possible to just point the LNB at the satellite and receive enough quality to watch tv?

I have a setup with a 30 cm dish and the signal is strong. Could I just do away with the dish altogether? Maybe put some sort of feedhorn on the LNB?
 
Someone posted an experiment here about a year ago.
They used a metalized CD as a reflector onto an LNB.
Since the flat disc surface is no better than aiming the LNBF at the sky, I'd say it's just possible.

But is it practical? No.
It's far more fun to go play with undersized dishes IMO.
You'll find a lot of that here on the forum, too. :rolleyes:
 
Another problem you'd have is the dish also isolates the signal from surounding sats. You could try putting a few CDs infront to create a tunnel effect, or a pringles can. I'm gona try that when I get home in a few months. Just for fun
 
Yes, I think the test was on a circular DBS satellite.
The reflector took care of the reversal of polarity.

Well, not a very productive field to explore. :)
 
Cone Antenna for FTA

Let's assume you're located within a really strong area of a footprint and the weather is superb. Would it be possible to just point the LNB at the satellite and receive enough quality to watch tv?

I have a setup with a 30 cm dish and the signal is strong. Could I just do away with the dish altogether? Maybe put some sort of feedhorn on the LNB?

Another approach........

reflarea.gif



Also.....
http://www.satellites.co.uk/forums/...25121-my-collection-homemade-antennas-ku.html
 
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Well, since the original subject said LNB, not LNBF, and since the circular DBS signals are the only ones that would make this even remotely possible, I don't think it would work, because there isn't any such thing as a circular LNB. Ie the discussion of reversing polarity via receiver or reflection won't do anything for an LNB, which will have only a linear probe. Now with a circular LNBF, then yeah, that would be an issue. Still hard to believe that it would work. I sort of remember the post on the experiment, but wonder if it was somehow working as a freznel lens or whatever it's called, and however it's spelled, and somehow acting to give some gain. I've read posts from people who have held up a bare LNB at the focal point of a dish and gotten reception without a feedhorn, but I can't imagine there being enough gain even for the DBS sats if you just hold it up to the sky with no gain at all , and the previously mentioned fact that it wouldn't separate ANY other sats, let alone adjacent ones, makes me really skeptical that it's even worth trying.
 
AAAAHHH the freznel

I sort of remember the post on the experiment, but wonder if it was somehow working as a freznel lens or whatever it's called, and however it's spelled, and somehow acting to give some gain. .

And yet another way.......
 

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There was an article in telesat about someone making omni directional dome antennas using different density materials. It would act similar to how a freznel lens does.
 
Never thought of the necessity to reverse polarities.

Adam: great experiments. I dig the umbrella. Also, do you have any guidelines for making those cone antenna's? i.e. length, creflective materials etc.
 
Paul Wade HDL_ant program

Adam: great experiments. I dig the umbrella. Also, do you have any guidelines for making those cone antenna's? i.e. length, creflective materials etc.

There is a program for designing Cone Feedhorns that Casser used. Google Paul Wade and download a copy of hdl_ant. It does the design and creates a pattern to cut from.

More on Cones...... and spheres of sugar, Adam;-)
 

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Thanks Adam

I never thought of antenna's other than dishes. Interesting to know that there's a couple more options.
Still, if any of you did some experimenting with the LNB sans dish, I'd be glad to hear.
Maybe the thread should be renamed to 'reception without a conventional dish'.
 
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