GEOSATpro GeosatPro 1.2 LNBF distance (1 Viewer)

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N6BY

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I am trying to optimize reception on my 1.2 meter GeosatPro dish. The SatelliteAV website lists the focal length as 23.62 inches. But wiith the support arms that came with mine, it would be impossible. Maybe the 23.62 is if it was used as a prime focus (not offset) dish? When I measure the distance between the center of my dish and the front of the LNBF, its around 30.5 inches.

What should the optimum distance be? I am wondering if someone can measure theirs?
 
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RimaNTSS

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Of course it is possible to find anything in Google..... images and descriptions. Perhaps it is even possible to find antenna's exact dimensions and parameters and the way how to measure focal distance on it. In Geosatpro 1.2m dish case focal distance is 23.62 inches (60cm) when measured from the center of paraboloid from which antenna is cut-off. And this center of paraboloid is located little bit lower (about 17mm) than lower point on the working area of the dish. Basically, if you measure distance from the lowest point on the working area of the dish to it's focal point it will be exactly 23.62 inches.
And, BTW, offset dish can not be used as a prime-focus dish.
There is picture, which can help you to tune GeoSatPro 1.2m. GeoSatPro120.jpg
 
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KE4EST

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I measure 29.5 inches from the Azure*Shine logo to the face of the LNBF. My LNBF is pushed back in the holder as far as it will go. ie, it can not get and farther from the reflector.
 
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N6BY

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I measure 29.5 inches from the Azure*Shine logo to the face of the LNBF. My LNBF is pushed back in the holder as far as it will go. ie, it can not get and farther from the reflector.
Thanks Michael.

Another question ---

There are 2 ways to the side arms to the bottom arm:
1) To the same bolt hole as the LNBF
2) To the other bolt hole closer to the dish

I have attached photos showing both possibilities. Which bolt hole should the side arms be attached to?

gsp1.jpg
gsp2.jpg
 

Titanium

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If mounting a KU-band feedhorn, use the end mounting holes and pass through the LNBF clamp. If mounting a C-band feedhorn, use the inner holes.

The inner holes lowers the arm to place the C-band clamp at the correct height to center the larger C-band feedhorn opening at the sweet spot (convergence point) and provide clearance for a conical scalar.
 
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N6BY

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If mounting a KU-band feedhorn, use the end mounting holes and pass through the LNBF clamp. If mounting a C-band feedhorn, use the inner holes.

The inner holes lowers the arm to place the C-band clamp at the correct height to center the larger C-band feedhorn opening at the sweet spot (convergence point) and provide clearance for a conical scalar.
OK, thanks -- that makes sense. Now I should be able to get it dialed in.

.... I have had this 1.2 meter dish for a long time, but never really got around to setting it up properly and optimizing it. Because shortly after I bought it, I found a BirdView on Craigslist.
 

N6BY

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Well I finally figured out why I couldn't get my 1.2 meter dish aligned. Looking at it from the sides, its bent by quite a bit! On one of the sides I can also see a dent on the edge.

I don't know how or when this happened, but it sure looks like I am going to have to buy a new one!

gspro2.jpg
gspro1.jpg
 

primestar31

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Well I finally figured out why I couldn't get my 1.2 meter dish aligned. Looking at it from the sides, its bent by quite a bit! On one of the sides I can also see a dent on the edge.

I don't know how or when this happened, but it sure looks like I am going to have to buy a new one!

View attachment 128452 View attachment 128453

Take the lnb arms off, and remove the reflector from the mount. Grab ahold of the reflector like a steering wheel of a car while you are standing up. QUICKLY push it away from you, and then PULL it back towards you. If you must, do this several times. It may POP it back into proper shape if it's "shipping warp".
 
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N6BY

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Take the lnb arms off, and remove the reflector from the mount. Grab ahold of the reflector like a steering wheel of a car while you are standing up. QUICKLY push it away from you, and then PULL it back towards you. If you must, do this several times. It may POP it back into proper shape if it's "shipping warp".
I just tried your suggestion and couldn't get it to pop back into place. But it was worth a try.

I also tried placing it on a level surface and pushing down hard. The warp remains.

The only good thing about this is that now I will no longer be wasting my time trying to get a decent signal out of it. Now its a snow saucer! :)
 

RimaNTSS

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N6BY I am sorry to see your dish in such a bad shape. If you were posting those picks in the first post, that would prevent any future questions. If you are going to buy another 1.2m dish, what brand are you looking for? To prevent warping of your future dishes, I would suggest to look for second-handed glass dish, like Channel Master (or whatever name it has). Good luck.
 
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N6BY

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N6BY I am sorry to see your dish in such a bad shape. If you were posting those picks in the first post, that would prevent any future questions. If you are going to buy another 1.2m dish, what brand are you looking for? To prevent warping of your future dishes, I would suggest to look for second-handed glass dish, like Channel Master (or whatever name it has). Good luck.
A warp-proof 4 foot dish would be nice. The only ones I have seen in my area are usually on top of old buildings and gas stations.
 
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RimaNTSS

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You never know...... sometimes the thing (dish in your case) can be just around the corner, you go there and take it! :confused: look in the local classifieds or to to the gas station and ask them whether they still need antenna on the roof. It can take some time, but you will get what you are looking for..... that is for sure.
 

a33

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I also tried placing it on a level surface and pushing down hard. The warp remains.

Well, to 'reform' the dish you'll have to push beyond a level surface, I would think. The parts of the rim that are now too deep, should be pushed further to the front, than where they are supposed to end.
No garantees, of course. But it is useless in this form, so you could try anyway.

I had a dish with a much much smaller warp than yours, and I managed to get it flat again in the above manner.

Bad luck, though, to have such a deformed dish....

greetz,
A33
 
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N6BY

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Well, to 'reform' the dish you'll have to push beyond a level surface, I would think. The parts of the rim that are now too deep, should be pushed further to the front, than where they are supposed to end. ...
I tried your idea, but with the dish facing up. I put it on the carpet, stood in the middle of it, and my wife and I simultaneously lifted opposing sides that were too low.

It seems to have worked. :thumbup As a test I put the dish upside down on a flat surface and it looks pretty close to what it should be, but not perfect.

The real test will be when I bolt everything back together and try it out -- tomorrow when its daylight.
 
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N6BY

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It works! I remounted the dish and tested it on 97W and 99W. It does the job, and there was one surprise compared to my Birdview.

On 99W the Birdview could not get 12112 4250V, which was a news feed from Puerto Rico, but the GeosatPro could. But there was another channel that the Birdview got that the the GeosatPro couldn't. I am pretty sure this is because of the different LNBFs, and not a neighboring satellite because I cant get 12112 4250V when I move the Birdview around.. The BirdView has an Invacom LNBF and the GeosatPro has a SatelliteAV SL1. When comparing the same channels that both dishes could receive, the Birdview had a much higher signal quality. Both dishes got nearly the same number of FTA channels on 99W.

From the pictures you can see that the dish is still a little bit bent near the top on one side (Its where the dent is). But I fear that if I try to bend it more I could mess it up. Its working well enough now for my purposes. And I like the fact that it gets a couple of news feeds that the Birdview doesnt.

gspro1f.jpg
gspro2f.jpg
 
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