In a message dated 98-08-20 09:26:40 EDT, ni6w@yagistress.minden.nv.us writes:
Statement #1:
> What will enable us to make
> direct
> > comparisons between antenna and tower figures?
>
> The flat projected areas will.
Statement #2:
> The new Hygain values are directly applicable to the 222-E Rohn tower
> layout
> drawings. I just got a new catalogue from Champion Radio that contains
> 222-E
> drawings. Please advise when the 222-F info is available. Since, the EIA
> (and most
> other) spec's allow a reduction in wind loading of an antenna (they call
> it an
> appurtenance) based on the use of "round members", we get to use the
> larger areas
> contained in the oval outlines of the Rohn diagrams. We get to use a
> larger area
> because the "round membered" antenna needs more projected area to
> produce the same
> load on the tower as a "flat membered" antenna (values in the
> rectangles). The
> area in the rectangle produces the same load on the tower as the area in
> the oval.
> The only difference is the shape of the members.
> This is a clue not to build your antennas with square or rectangular
> tubing,
> because it has a higher drag coefficient and will result in higher loads
> on the
> tower!
>
In Statement #1 you say " The flat projected areas will."
In Statement #2 you say "we get to use the larger areas contained in the
oval outlines of the Rohn diagrams".
Aren't these contradictory? My question still remains - "WHICH figure do
we use to determine Rohn antenna load capacities vis-a-vis amateur yagis?"
Cheers, Steve K7LXC
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