Thanks. I don't know if I understand all of that But I will think about it.
My plan is to use a tiltover 22 ft tower to support a 25.7 ft tall vertical.
The tower is actually part of the entire vertical antenna.
It will have a 60 meter trap at the 43 ft point and will also radiate on
3.650 MHZ.
Along side the tower will be an aluminum tube with a 30 meter trap and a
small stinger above it.
This will give me 30/40/60/80 meters in one assembly.
I have the traps already made.
Soon I will pour concrete and get this guy up in the air.
Depending on other things, I may put a switchable base loading coil in for
160 meters.
My winds in SW FL rarely get above 50 mph gusts. then there is a dead band
in speed until you get to hurricane force winds.
So, I am also including a base mounted hinged gin pole to tilt it over in
really bad weather.
Dan Schaaf
K3ZXL
"In the Beginning there was Spark Gap"
www.k3zxl.com
----- Original Message -----
From: "Gene Smar" <ersmar@verizon.net>
To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Sent: Thursday, February 18, 2010 3:47 PM
Subject: Re: [TowerTalk] wind load
> Dan:
>
> For a RIGID vertical element (such as an antenna mast or a heavy
> vertical made of thick-walled or solid tube), the force (say, 12.54 psf)
> would be applied midway up the element, or at 11 feet above the ground or
> tower top. (You can find the calculus for this in most introductory
> mechanics text books.) The area this force is applied over is the
> effective
> area of the mast or vertical antenna. So assuming an effective antenna
> area
> of 3.67 sqft (the actual shadow area of a 2 inch mast 22 feet long), the
> total force applied would be 12.54 X 3.67 = 46 pounds. The force would be
> handlied as a force at 11 feet AGL or above the tower top. We all must
> take
> this additional force and area of the mast into consideration when
> calculating the total wind force applied to the tower system.
>
> As for a real-world vertical that flexes in the wind, this will shed
> some of the wind loading leading to a reduction in total force applied to
> the vertical antenna. The actual number depends on how far the antenna
> bends in the wind. But by using the non-bending answer for a rigid tube
> you
> will be taking the conservative (safer) approach.
>
>
> 73 de
> Gene Smar AD3F
>
>
>
> ----- Original Message -----
> From: "Dan Schaaf" <dan-schaaf@att.net>
> To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
> Sent: Thursday, February 18, 2010 3:02 PM
> Subject: Re: [TowerTalk] wind load
>
>
>> How does this wind loading information apply to a bertical antenna which
>> is
>> rigidly mounted at the base and flexes in the wind?
>> In addition, if the vertical antenna is mounted on top of a 22 ft tower,
>> which is anchored in concrete, how does this info apply?
>> 22 ft tower is short in comparison and maybe can be considered
>> non-movable
>> and then the vertical can be seen as the same as if it were mounted on
>> the
>> ground.
>>
>> Dan Schaaf
>> K3ZXL
>> "In the Beginning there was Spark Gap"
>> www.k3zxl.com
> /towertalk
>
> _______________________________________________
>
>
>
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