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[TowerTalk] Antenna & Tower Wind Load Ratings

Subject: [TowerTalk] Antenna & Tower Wind Load Ratings
From: Kurt Andress <andresskurt@gmail.com>
Reply-to: kurt@k7nv.com, jim.thom@telus.net
Date: Sun, 18 Jun 2017 21:57:40 -0700
List-post: <mailto:towertalk@contesting.com>
Jim,,
I knew you were a smart guy! That's exactly how it is with EIA/TIA 222-G.
The spec is really detailed and very tough! Why? Because the teams of tower engineering professionals studied all the failures they found in the industry, and cranked up their methods to get it all much more reliable for the diversity of site locations and conditions towers would see....! We are better off now that they have done that! And, we're about to get Rev H......? Yes, the windloads are dependent upon all sorts of site variables, that actually makes real good sense!

If I was allowed to release confidential datasheets that I have created for a couple of your well known antenna companies, you would see that they are all created with all of the 222-G variables at declared antenna heights.......etc.....they are completely compliant with the latest standard, and I have developed software to remain compliant with almost every site variant! I did not do this because someone was gonna pay me lots of money to spend my time to do it, I did it because it was simply the right thing to do, so I could know I owned it, and could do battle with anyone about the voracity of my enterprise! That alone has been several hundreds of unpaid hours to just be able to get things right for my clients, or occasionally make posts to TT, where I expect many will probably challenge or try to take me down about that....? Bring it on, I'm simply a human and capable of human error....but I've been doing this for long enough to think I understand it, and have it right!

Jim, technical correctness, is in the eye of the beholder! When technology and the understanding of it exceeds our wishful convenience, you get to decide what to do with that.......? The engineers on the EIA tower committee did what they did, because it was better and more correct for what they had learned....there is absolutely no reason for all our existing antenna manufacturers to be citing effective antenna areas from a 27 year old obsolete spec, that is not compliant with the current spec, and is not the correct antenna area numbers we think the tower designers are using Tower designers do not clearly state what antenna area they are rating their tower for, and antenna suppliers are not saying what their antenna area means, so no one can match up antennas with towers! And, there is a lot more behind that which needs to be done to properly figure out what the mast, rotator and antenna placements on top of a tower do according to what the single point load rating for the tower is....I put lots of simple stuff in the 19th Edition of the ARRL Antenna handbook about it (all of it is still there in recent versions), and made a more detailed presentation at the 2012 Dayton Contest University about these things.....and a lot more about why antennas eat rotators....

73, Kurt, ......I've got to get real stuff done here, for real people that need it, right away.......back to net!
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