[TowerTalk] RE: Tower Wind Calcs

[Jim Lux]

It may not even be possible to have any antenna area at 90..
The allowed cross sectional area is dropping faster than windspeed squared..
There's something else at work than simple canteliever loads here.
16.5 sq ft @ 50 mi/hr => 106 pounds
6.8 sq ft @ 70 mi/hr => 85 pounds
Continuing the trend... at 90 mi/hr, even as small as 3 square feet, you're
at 62 pounds
Something like a Ringo Ranger probably has a cross sectional area of 3
square feet...
I'll bet the screwdriver antenna on my car has a cross sectional area of 3
square feet..

----- Original Message -----
From: "W7AOR" <w7aor at narri.org>
To: "Alan C. Zack" <k7acz at cox.net>; <TowerTalk at contesting.com>
Cc: "Las Vegas Radio Club" <lvrac at yahoogroups.com>; <reginfo at arrl.org>;
"Antennas" <antennas at mailman.qth.net>
Sent: Thursday, December 11, 2003 3:41 PM
Subject: [TowerTalk] RE: Tower Wind Calcs


> Nevada P.E. wet stamp on docs for $250. Take it. That is cheap. No PE
local
> could do that.
>
> Interesting that Henderson is asking for 90 mph. I thought that one could
> just put up a tower in Henderson with the city being interested. Clark
> County asks for 70 mph.
>
> Beware that the original calcs for US Towers MA-40 is done at 50 MPH
> Winds -- 16.5 sq feet; 85 lbs and at 70 MPH Winds -- 6.8 sq. feet; 65 lbs.
> so at 90 mph what do you think happens to allowed antenna loading and
> weight?
>
> Good luck!
> Kent W7AOR
> www.narri.org
>