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Re: [TowerTalk] Antenna & Tower Wind Load Ratings

Subject: Re: [TowerTalk] Antenna & Tower Wind Load Ratings
From: TexasRF--- via TowerTalk <>
Date: Fri, 16 Jun 2017 08:01:39 -0400
List-post: <>
Many of the commercial wireless internet antenna manufacturers specify  
their antenna loads as pounds or Kilograms of force at a given wind speed. This 
 seems like a non-ambiguous way to handle wind loads
Gerald K5GW
In a message dated 6/15/2017 11:13:21 P.M. Central Daylight Time, writes:

Jim  Lux,
Thank you for contributing to this discussion!
I don't think we  agree about everything said, but that is quite ok!
All I intended to do  with my initial post....was to remind those on this 
reflector now, that  what I told them was wrong a couple of decades ago, 
is still  wrong!
I'll leave sorting it all out to all you Stellar Experts that chose  to 
take up the challenge......
I would warn everyone to not try to  outsmart the EIA/TIA-222 Standard, 
we aren't NASA or Boeing, what happens  on towers near the ground, is not 
what happens up at 35,000 ft for Roger,  K8IA....
One that studies the 222-G mathematics will find out that the the  wind 
pressure gradients go away and become constant at around 400  
ft.......the member oscillations that K8IA mentions are due to a  
phenomenon known as "vortex shedding", that is well documented and  
happens at rather low wind speeds with the antennas we use, when  
insufficient element taper schedules are present to prevent all of the  
individual element members to go into oscillations together....around  
the same range of wind speeds they closely share. I have been on lots of  
towers to see antennas do this, and have designed elements that don't do  

I feel no longer qualified to hang with all the  tremendous Cerebral & 
Pundit brainpower that has been brought to bear  here, so I will kindly 
back out of this.
I accomplished what I wanted  to do....simply to remind the current TT 
readers that after ~ 35 years of  trying to get people to do these things 
right, these simple things are  still not being done right!
Thanks to all that read's up to you  to demand technical 
correctness from your vendors!

73, Kurt,  K7NV

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