[TowerTalk] Modeling Rohn 25G in K6STI's AO

[Dan Maguire]

Jim Brown wrote:
>>> I've seen a simple equation for modeling a straight triangular tower in NEC. As I recall, the diameter worked out to be around 0.65 the width of a side. This would account for modeling it as a radiator.

The image just below "Wire Geometry" on page

https://ac6la.com/aecollection8.html

shows the equivalent diameter for Rohn 25G according to:

a) Section 9.1 of Leeson's "Physical Design of Yagi Antennas"

   EquivDia = SQRT(Area / PI) + Perimeter / (2*PI) = 9.55 inches

b) Wikipedia page https://en.wikipedia.org/wiki/Antenna_equivalent_radius

   EquivDia = 2 * (LegDia/2 * FaceWidth^2)^(1/3) = 8.58 inches

I'm afraid I don't know which is "more correct".

Dan, AC6LA