gunther_01
Premium
join:2004-03-29
Saybrook, IL
| Pac wireless
I was thinking there was a post about this years ago. But it happened to me also.
A couple of years ago I installed a pair of these antennas »pacwireless.com/products/ES58-17.shtml for a very short in town link. It always seemed to be a weak signal, but I left it since there is a slight amount of foliage that could have interfered. It was also my first wireless link.
As it turns out one of them was mislabeled and the polarities were off 90degrees. I found this out by replacing a possible bad unit with a higher gain grid unit Friday.
Now for the interesting other part. I also have a pair of 2' PAC dishes installed for a 9 mile link. I had been running on 5.3 feedhorns using Osbridge/HGA 5GXn units. I had wanted to use 5.8 but was sent the wrong feedhorns forever ago. That link has had a great signal -63 average since I got it lined up. Friday I changed out the 5.3 feedhorns with 5.8 on both ends. I now have a -80 average. I have checked all channels and it's the same.
Has anyone every had a feed horn internally mis-aligned out of polarity? I know they are installed correctly. I also did not realign the dishes thinking that it should be aligned from the other setup. Maybe that was wrong to do as well. But it was pretty windy Friday 30-40Mph and 130 and 200 feet up. So I really didn't want to unclamp those dishes either. |
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viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA | What is your noise floor like?
Have you thought of the possibility there is more noise in 5.7 then in 5.2?
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ComTrain Certified Tower Climber. American Tower Certified approved contractor |
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Chele
join:2003-07-23
| reply to gunther_01
Some day I'll start smoking just so that I can use the backfire series for ashtrays, in the mean time their being used as piss pots  I bought a bunch of them to test. The link would be lousy no matter what frequency, polarization, or sector was being used. It appears that the grid itself is the same for the particular frequency range(11.a) and the only difference is the feedhorn. I have used one frequency sector with a different frequency CPE's with no serious ill effects. I did a test once with a 5.2 and a 5.8 29dBi grids and the difference was I think 1-2 dBi's in the SNR. Mind you, it was not a very precise test. I installed one grid checked the SNR, installed the other antenna and did the same, just checked the SNR nothing else. |
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LLigetfa
join:2006-05-15
Fort Frances, ON | Are the feedhorns universal with multiple mounting positions for either/both the focal point or/and polarity? If so, I would double-check for improperly positioned feedhorn. |
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gunther_01
Premium
join:2004-03-29
Saybrook, IL
| reply to gunther_01
I have thought about it, but I don't think the 5GXn units show actual noise. The StarV3 unit that is located at the client side for another PtP master isn't showing any noise in that band. Of course it's a PtP facing 90degrees off of the one in question.
I don't rule that out, but this is a link in the middle of no where over farm land. And for the most part I have the highest point around. I would just think (assume) that 5.8 would have been better and legal for the power used.
I do plan to test at some point as to whether or not the feedhorn is on the wrong polarity. I didn't Friday since I had had enough of the wind for that day. I don't have to climb it so pretty easy to do later. |
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gunther_01
Premium
join:2004-03-29
Saybrook, IL
| reply to gunther_01
The echo series dome antenna is a "turn the whole thing 90 degrees" antenna. You need to remount the mount after wards to mount to vertical mast. The 2' dish has a separate feedhorn that is turned. It has a screw on the feedhorn that is used for the location of polarization. Screw up is Vert, screw sideways is Horizontal. There are notches in the Dish for this screw to set in for the polarities. The Pac grids are pretty much a turn the whole thing, but you need to remount the mount in order to attach it to a vertical pole. |
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gunther_01
Premium
join:2004-03-29
Saybrook, IL | reply to gunther_01
Focal point on Dishes are preset with feedhorn length, it's a fixed unit. |
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LLigetfa
join:2006-05-15
Fort Frances, ON | OK, then polarity is the likely culprit. Just out of curiosity, compare the length of the old feedhorns with the new one. Maybe they sent the wrong length. |
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Chele
join:2003-07-23 | reply to gunther_01
I meant to say the test was done with grids, not Backfire POS. |
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