w2pm@aol.com wrote:
> I saw a few posts on here a few weeks ago - one from Herb - describing
> a helically wound 60ft vertical using the new long fibreglass
> telescoping pole from Spiderbeam. At a hamfest here there's a guy
> selling miliary surplus 4ft section fibre/composition poles which plug
> together. A real bargain - a 40 ft kit with guy set and base about
> 30.00 and the 4 ft sections were 30.00 for > 60ft worth. These are very
> rigid, mil green.
>
FWIW...I use both the fiberglass and aluminum surplus cammo supports and
while the fiberglass poles seem very rigid individually they tend to
flex quite a lot when telescoped together, even at the 32-foot level.
You *can* walk up the aluminum poles at that height, which is what I use
for my 40-meter 1/4-wave vertical, but the flexing is substantial and
the fiberglass flexes considerably more. When up the aluminum vertical
is very stable guyed with Dacron line only at 28-feet...mine has been up
for more than 3 years. There is a bit of resonant "dancing" in a 60 to
70 mph wind but nothing that would require a second set of guys.
Although I have never tried to go beyond 32 feet with the fiberglass
poles I am pretty certain, based on the amount of flex at that height,
that they would require two sets of guys at 40 feet and possibly three
when at 60 feet. It would, without doubt, be necessary to use a pivot
pole to get a 60-foot set of the fiberglass poles erected. I have
attempted to walk up 64 feet of the aluminum mast, to be used as my
80-meter vertical, and quit because I was very uncomfortable with the
amount of flex. I am now trying to get a 30-foot length of steel mast or
pipe that is sufficiently rigid to act as a pivot pole.
That is a brief account of my experience with cammo supports. I hope it
is of some value.
73,
Jack, NA7RF
Silver Springs, NV
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