[OKDXA] Fwd: Antenna Orientation in Wind.

[W5LE]

-------- Original Message --------
Subject: 	Antenna Orientation in Wind.
Date: 	Fri, 1 Nov 2013 17:56:08 -0500
From: 	D C _Mac_ Macdonald <k2gkk at hotmail.com>
To: 	W5LE - Gene Lewis <w5le at beggstelco.net>
CC: 	NE5S-Cox Dave Duskin <ddgold at cox.net>, "N5OK-Home, Coy Day" 
<n5ok at arrl.net>, D C _Mac_ Macdonald <k2gkk at hotmail.com>



Hi, Gene.
The following message showed up today on the SteppIR mailing list.  I 
don't know if it is applicable both SteppIR AND all-aluminum beams but 
the info bears consideration.
I don't have an email address to send to all of OKDXA, so maybe you can 
pass it on to the general membership for me!

* * * * * * * * * * *
* 73 - Mac, K2GKK/5 *
* (Since 30 Nov 53) *
* k2gkk at hotmail.com <mailto:k2gkk at hotmail.com>*
* Oklahoma City, OK *
* USAF & FAA (Ret.) *
* * * * * * * * * * *

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To: SteppIR at yahoogroups.com
From: orville
Date: Fri, 1 Nov 2013 13:25:25 -0500
Subject: [SteppIR] Antenna Orientation in Wind.


One of my friends sent me an email, excerpts of which follow:

“Six minutes before the end of CQ WW Phone last weekend, under clear 
blue skies, we had a rogue wind come over the hill for about 10 minutes. 
Wind speed at 20’ was 50MPH. We can’t even imagine what it was at 170’ 
where the top 80m beam is. They are designed for 110MPH. In the video, 
you can see the monopole turning 180 degrees (intentionally) and the 
element righting itself. The reflector is damaged but useable and will 
require several crane days to replace the OEM rope side trusses with 
Phillystran. If there ever was empirical data for leaving the elements 
broadside to the wind or element tips to the wind, it is DEFINIETLY 
element tips to the wind.

Video by WW1X.

http://www.youtube.com/watch?v=DbMiXpE9dFU

Don’t try this at home.”

I hope this helps in your decision as to antenna orientation. Of course 
the SteppIR antennas don’t have the wind loading of stacked three 
element 80M yagis, but the data is appropriate.

Orville, K5VWW