In article . 196,
Ed wrote:

I am considering putting up a ground mounted vertical antenna, based
on using telescopic aluminum tubing such as is available from Texas
Towers or DX Engineering. Tubing available ranges from .500 inch to
2.125" with corresponding increase in price as diameters increase.

My vertical should be limited to a maximum of 30 feet, but preferrably
around 23 - 25 feet. I will feed it with an SGC coupler at the base and
operate 80M - 10M.

My question: Using the 6' long aluminum pieces, what is the minimum
diameter sizes I should start with to enable the antenna stand up to a
75mph wind UN-GUYED. Also, how much "overlap" should I use in the
telescoping pieces?

I will consider alternative means of building the vertical, but I
really wish it to be unguyed .

Any info or recommendations appreciated. TNX

Ed K7AAT

a couple of points come to mind here. First, Your not going to get much
out of a 30 Ft Radiator tied to an SGC Autotuner, UNLESS you have a
REALLY LOW Impedance RF Ground for you Antenna System. Radiator is just
to short. It would be a lot better is it were 70 Ft tall.
Second, there are, what is Known in the Marine Radio Trades,
"Pre-corroded Aluminum Alloys" that already have an Aluminum Oxide
coating on the interior and exterior surfaces. Then the trick is, to
get a good Metal to Metal Bond between the joints of the separate
tubing pieces. Usually done with Threaded Bolts, in Drilled and Taped
holes, and coated with Ú, or other such conductive substance.

--
Bruce in alaska
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