[TowerTalk] MODEL FOR TOWER

[jimlux]

On 4/22/19 8:53 PM, Greg Best via TowerTalk wrote:
> I have an 80 ft Rohn windmill tower that is equivalent or stronger than the same height SSV. The base dimension is 7’ 7” and the tower tapers to 24 “ at the top . I am wondering if anyone has a NEC model for this tower (or a very similar one)?  I have a 20 m 4 el yagi I am considering installing at abt 60 ft and I am concerned about the tower impact on the pattern. The yagi at 60 ft would be in a stack with another yagi at 95 ft that is mounted on a mast.
> 
> 

This is one of those things that might be easiest to generate with a 
short program in the language of your choice to generate the lattice of 
vertical, horizontal, and diagonal members.   I've done that to generate 
a model for a truss - it was easier to do that than to try and figure 
out the coordinates by hand.

There *might* be a cad program in which you could quickly draw the 
tower, and export the segment endpoints.

Because it's tapered, it doesn't lend itself to using a GM card to 
replicate segments.

You'd model it as a wire for each structural member, and pick the 
diameter of the wire to have the same circumference as the perimeter of 
the structural member (or, heck, just make em all 2" diameter wires).


for each section do:
	calculate the coordinates of the 8 corners
		(or 6 corners if it's three sided)
	generate a wire for the 4 verticals corners
	generate wires for each of the horizontals
	generate wires for the diagonal braces