[TowerTalk] Modeling a self supporting tower interaction

[Leeson]

 From "Physical Design of Yagi Antennas," ARRL 1992, pg. 9-2:

"This problem is resolved in a short paper by Jaggard [D. Jaggard, "On 
Bounding the Equivalent Radius," IEEE Trans AP, Vol. AP-28, May 1980, 
pp. 384-388, https://ieeexplore.ieee.org/document/1142336] Jaggard shows 
that the equivalent radius ae of a noncircular shape must lie between 
the radii ai and ac of the inscribed and circumscribed circles which 
geometrically bound the noncircular conductor. Further, he shows that 
these bounds can be narrowed by the use of radii ain and aout which are 
the radii of circles of the area A and perimeter P of the cross-section 
shape of the conductor, ain = sqrt(A/pi) and aout = P/2pi. A 
satisfactory estimate for the equivalent radius is the mean of the two 
bounding radii."

A freely downloadable scan of my 1992 book with more details about the 
equivalent radius of irregular shapes, "Physical Design of Yagi 
Antennas," is at
https://www.dropbox.com/s/hmhkeofz0igrg1e/Physical%20Design%20Of%20Yagi%20Antennas%20D%20B%20Leeson%20V2.pdf?dl=0

73 de Dave, W6NL/HC8L

On 6/25/24 5:40 AM, john at kk9a.com wrote:
> To check for interaction, I have done the easy model method of using
> a very thick wire for the tower.  Since the tower is triangular and a
> wire model is round, I took a wild guess at the wire diameter.  I
> never thought of matching the surface area.
> 
> John KK9A
> 
> 
> 
> 
> Jim Lux wrote:
> 
> There's two ways to approach the modeling.  The easiest is to model a
> "very thick" wire - match the surface area of the tower with the
> surface area of the wire.
> 
> 
> 
> _______________________________________________
> 
> 
> 
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