Pete:
Agreed. In the version of the posting that I did NOT send out I had
included details of my antennas and what method I used in the model. I
thought better of providing this info for fear it may be misapplied. I will
say that I took a conservative approach when I modeled my installation.
However, what the Trylon software DOES demonstrate is that one gets
dramatically different results when assuming the antenna elements are round
vs flat plate. It also shows what happens to the stresses on a selected
tower when the antenna load is moved up the mast. One can see how easily a
tower can fail by installing a significant antenna sail area ten feet above
the top of the tower. Plus, at least in the model of my tower and antennas,
the first tower segment to fail is NOT the bottom one. Interesting.
BOTTOM LINE: Caveat Amateur.
73 de
Gene Smar AD3F
----- Original Message -----
From: "Pete Smith" <n4zr@contesting.com>
To: "EUGENE SMAR" <ersmar@comcast.net>; "TowerTalk"
<Towertalk@contesting.com>
Sent: Thursday, June 26, 2003 2:11 PM
Subject: Re: [TowerTalk] Trylon software
> At 12:03 PM 6/26/03 -0400, EUGENE SMAR wrote:
> >TT:
> >
> > I found an interesting piece of software on the Trylon Titan web
page:
> >http://www.trylon.com/lightdutytowers/selfsupporttwrs_size_towercalc.asp
.
> >It's the program Trylon use to determine whether a selected tower will be
> >adequate for a combination of proposed antenna loads. You'll need to
input
> >the antennas' wind area and other parameters regarding the physical
> >arrangement on the mast.
> >
> > I suggest you read the instructions and thoroughly understand them
(and
> >the caveats) before you apply them to a proposed configuration of TRYLON
> >TITAN TOWERS (emphasis intended.) If nothing else, you can see the
effect
> >of increasing antenna mounting height on the reactions at each section of
> >tower.
> >
> >73 de
> >Gene Smar AD3F
> >P.S. Don't forget to include the wind area and weight of your mast.
>
>
> And K7NV would be disappointed if I didn't also caution to be careful that
> the antenna wind area figures you use are calculated on the same basis as
> the numbers that Trylon uses to rate its towers. Combining apples and
> oranges can result in trying to put as much as 1.5 times the rated amount
> of antenna area on the tower.
>
> 73, Pete N4ZR
> The World HF Contest Station Database was updated 17 June 03.
> Are you current? www.pvrc.org/wcsd/wcsdsearch.htm
>
>
>
|