[TowerTalk] Triangular Crank-Up Wind Load Model

[KJ0M]

On Jan 16, 2006, at 17:12, Kinney John-r17512",  
J.Kinney at freescale.com wrote:


>
> I have a question pertaining to my Hy-Gain HG52SS tower or any other
> tower of this type for that matter.  The question: Does anyone have a
> model or has anyone attempted to model the wind loading of this  
> type of
> tower, at heights less than full extension?  This tower is rated at 9
> square feet at 50 MPH average wind speed.  It would be interesting, to
> me at least, to see a graph or table stating the increase in wind load
> capacity as the tower is lowered to its resting height (21 feet.)  I
> asked this question via email directly to Hy-Gain, after their  
> purchase
> by MFJ, but never received a reply.
> Thanks for the bandwidth.
> 73's
> John Kinney KA7CVJ

Frank Travanty, W9JCC, has written an Excel spreadsheet and an  
accompanying article which I have used for my TX-472MDP tower. It  
does just what your looking for in terms of allowing you to graph  
your particular installation.

It takes a bit of data input in terms of your particular tower. You  
will need wind loading figures per section, amount of overlap of  
sections. psi rating of your mast, antenna windloading figures and  
some other data all of which I don't recall since using the sofware.  
Anyway, you end up with a nice graph of height versus wind speed  
maximum for your installation.

I thought it was very well written and implemented. I have a copy of  
the Word document and the Excel spreadsheet. Contact W9JCC to see  
about getting them. I'm not sure if it's OK for me to send, but with  
his permission, I would be glad to forward a copy of each.

73,

Jim
KJ0M
.-.-.