In a message dated 960905 11:40:14 EDT, you write:
>I want to calculate the effective wind area of
>a 2" diameter mast that is 72" long.
>
>Therefore 72" X 2" = 144 sq.in = 1 sq.ft.
>
>The calculation above would be accurate if the
>mast were square. But because it's round
>isn't there a constant I neet to multiply the
>result by.
Hi, Gene 
You're just about there. The roundmember multiplier, or drag
coefficient, is 0.67. It is used by Dave Leeson, W6QHS, in his book
"Physical Design of Yagi Antennas", page 76.
The EIA/TIA222F uses a 'reduction factor' of .51e(squared) + .57
where e is the solidity ratio. They also have an appurtenance force
coefficient for a cylindrical appurtenance of 0.8 for an aspect ratio <7.
You should investigate it further to look at the definitions and
applicability to your question. This info is covered on pages 38
73, Steve K7LXC
TOWER TECH  professional tower supplies and services for amateurs
