Lostgallifreyan wrote in
:

tom wrote in
t:

I am getting answers that aren't quite for the question I thought I
asked, and that's a good thing.


... I got the idea from seeing how well reeds
will stand long after winter hits them, and from realising that the
dynamics in the aluminium were similar.

Crucial detail that did not survive the long reply I did not send, or get in
the one I did send: The aluminium was angle-sectioned, and used torsion as
well as bending to absorb force.

The insulated spacer and mount (crudely hacksawed hardwood from an old chair)
for the vertical dipole would damp the oscillations like a kind of 'anchor'
against the wind. The only time anything broke on it was a guy wire when mast
torsion made it bend and fatigue at the attachment point, but the mast never
fell even during the wind that did this to it, and this weakness can be
easily designed out. The metal mast never fatigues because it never flexes
beyond its natural spring tension at any point. If it did, it would have
fallen in weeks instead of lasting many years. The load at the top is only
about a half-pound, but the rest of the mast is less than double that, so
it's very efficient and cheap.