[Lowfer] re Antenna material question

[Andy - KU4XR]

Thank you for your reply Alan:

I appreciate your time and input. In 2 years of experimenting
at LF; I find myself saying " I have come to learn " a-lot.
I hope to raise the antenna height close to 2 meters higher
today. That is the highest I can raise it with the current
top-hat configuration. That will put the APEX at 8.6 meters AGL.
and my top-hat has 11 - #18 wires each 5.5 meters in length.
I have been advised that even this seemingly small amount of
extra heigth will be my greatest immediate benefit at LF, and
will help to raise R-Rad. I am currently using a single run
of #18 stranded wire as the vertical. I have wondered about 
the multiple lines but not sure how far to space each run to
minimize the capacitive effect. Or, I have plenty of 3 line
flat antenna rotator cable, # 18 guage with very close wire
spacing. The 3 wires tied together should reduce the DC res.
but I'm sure will add some extra capacitance to the vertical.
I have no idea as to the trade-offs there. At least my antenna
is single man manageable, so I can work on it by myself, 
it's just very time consuming when I do any work. 
I beleive that I will stay with a wire vertical, just deciding
what configuration will give extra efficiency versus just
having more copper in the air with no added benefit.
I don't have end insulators on the top-hat ( bad ) I am using
18 pound test Masons Twine tied directly to the top-hat wires
to pull them into the air. I ahve come to learn that when the
twine gets wet; it probably becomes a conductor to ground.
So that is another improvement to make by adding insulators
in the pull-up twine. **** I know about using weed trimmer
line, but I have hundreds of feet in the air, and the twine
is cheap. The insulators should take care of any conductivity
in the twine ( I think ).
At a minimum; raising the antenna higher, is todays job.

73 to all :::


Andy - KU4XR - EM75xr - Friendsville, TN.
LOWfer Beacon " XR " @ 185.29866 KHz ( QRSS-60 )
Coordinates:  N:  35* 43' 54" - W:  84* 3' 16"
http://www.myspace.com/beaconxr


--- On Sat, 11/7/09, Alan Melia <alan.melia at btinternet.com> wrote:

> From: Alan Melia <alan.melia at btinternet.com>
> Subject: [Lowfer] re Antenna material question
> To: lowfer at mailman.qth.net
> Date: Saturday, November 7, 2009, 4:28 AM
> Hi Andy, my thoughts are you could
> get some misleading answers here :-)) As
> I have said before about LF, a lot depends on the actual
> enviroment the
> antenna inhabits.
> 
> Whilst the increase in diameter gives a small reduction in
> "DC" resistance
> (which is GOOD) it also increases the capacitance to ground
> and the
> surroundings, which may be lossy, which is BAD. That is the
> "theoretical"
> aspect. If anyone has tried it, the only real reliable test
> would be
> extensive field strength measurements at  say a few km
> under similar weather
> conditions. This is not an easy thing to do whilst
> maintaining an accurate
> input to the antenna. Increases in antenna current may not
> indicate a higher
> field strength if the extra current is flowing to ground
> through a lossy
> environment rather than through the whole of the "radiation
> resistance". If
> you have a commercial sized antenna (like 300ft and acres
> for radials) then
> you might see a definite advantage. You might do better
> with two of three
> strands of  18 gauge wire for the vertical...easier to
> ensure a low loss run
> and no dissimilar metals problems.
> 
> Remember at LF putting up a new antenna often seems to
> improve things
> because you redo connection and clean insulators that may
> have been starting
> to give problems with the old installation. A reliable
> comparative test on
> this scale is extremely difficult.
> 
> Best Wishes
> Alan G3NYK
> 
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