Ed wrote in
. 192.196:


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.


I know you didn't ask about the radio performance of the proposed design.

Nevertheless...

It is challenging to achieve good efficiency from such an antenna (ground
mounted unloaded vertical, earth system, impedance matching at the base)
at less than about 17% of a wavelength in height. My article
http://www.vk1od.net/multibandunload...ical/index.htm models an
unloaded vertical of 10m (about 30') in height, and also considers a
better configuration (13m).

The article may interest you because it questions whether a 30' vertical
is a good antenna at 3.6MHz, or above 18MHz.

In any event, the bigger issue is what is under the ground rather than in
the air.

Owen