[TowerTalk] extending existing tower heights

[Graham McIntire]

Hi All,

I have a few existing towers that I've come to realize aren't as high as I'd
like them. The primary one I'm looking at doing first is a 100' Rohn 45g
guyed a little beyond Rohn's specs for 110mph winds (guys at 80', all 1/4"
EHS.)

My question is how much wind loading am I going to lose if I extend it
another 90' to 190' total with the guys still at 80' radius? I don't have
any HF or VHF gear on the tower, it's all microwave (a few sectors, small
dishes, etc,) so it's currently and will be fairly lightly loaded. How much
benefit would I get by doing 10 or 15' elevated guying at 80' over keeping
them on the existing anchors in the ground? Is there some sort of a forumla
I can use to help calculate the drop in wind load?

Thanks!

Graham W5ISP