" wrote in
message m...
2 other considerations - 1) copper tubeing is quite soft-- got birds? a
pigeon, or even lighter birds
will tend to bend the elements. But, - 2) even with 6061 T, /6063 T
(which is relatively hard drawn
tubeing), at the lenghts required for 6 meter yagis (aprox 55 inch on
EACH
side of the boom),
in wind even light by nevada standards ( like in Portland, Oregon),
"whistle" (resonate at audio frequencies), and because they VIBRATE at an
audible rate even in slight winds (have friend
he and me bought 1/2 each of a 6 meter 4 el X 8 yagi moonbounce array- I
used mine for makeing
2 meter antenas, the other guy put 4 stacked up on a 30 foot pole-- this
number of years ago.
Almost immediately, the elements started BREAKING from Metal Fatigue!!
Perhaps, as M2, and
several others have discouvered , elements that are SOLID 1/4 inch,
inserted
into 3/8 inch alumium
tubeing seem to hold up, while these (1/4, or 3/16) elements thru the boom
Break off right where they
pass thru the boom, or are anchored by a screw! There are other
considerations for antennas than Gain
Like Weight, Metal Fatigue, oxydation , dissimilar metals (electrolysis).
That it works for a day is one thing
good for a LIFETIME-- thats another story altogether!! Jim NN7K

I have had a light duty KLM 7 el 6m beam up for 20 years. During this time
it survived a 96 mph storm that felled trees all around it. Never heard any
vibration from it, but that may be because I braced the boom to the mast
with two 5 foot lengths of 3/8 Al. Had it been copper, and it was still up,
it would look like hell. I don't think hardware store Al would be a problem
on 6m elements. What you don't want to do is to make a big hole in it for
the mounting screw.

Tam/WB2TT