John, one may be able to model a vertical and ground system, but the proof
is in how it plays (or works) and that may be impacted more by soil and
local conditions which are not modeled.
Case in point; I have been using a ground mounted Butternut HF-2V or Bencher
HF-2V usually with the 160 meter mod kit and umbrella style top loading (
four 12 foot pieces of copper wire and string or weed trimmer line to guy
the HF-2V) for over 25 years at this location. The vertical sits above a
radial plate with twenty-four 66 foot radials laid on top of the grass (cut
short) and pinned down. The undisturbed soil is the black bottom muck of a
glacial moraine pond / lake some three feet deep over water bearing clay.
About half of the radial field is over the household septic leach field
which provides additional soil moisture from well water drawn from the
Mahomet aquifer.
I have had to repair and rebuild the HF-2V numerous times as the result of
damage from lawn tractors and deer. I've replaced it with a completely new
HF-2V at least once. The reason? Because it works so well; Wake, Baker,
Campbell, Peter 1 and many others worked, confirmed, and verified on 160,
80, and 40. Are the radials driving the vertical performance of plus or
minus 3 dB or is it soil conductivity or an organic reflector? Or is it
something else?
One other thought is what kind of vertical are you using versus the model.
The HF-2V uses the entire vertical length (as the result of loading coils)
and bottom feed, whereas other antennas use traps to achieve resonance and
may be using elevated feed point.
73 ES DX,
Gary -- AB9M
-----Original Message-----
From: [email protected]
Sent: Thursday, January 23, 2014 11:44 AM
To: [email protected]
Subject: [TowerTalk] Effect of ground radials
This is the first time I got zero response on towertalk, so I will try to
rephrase my question. We all know that having a good ground system on a
vertical reduces ground loss. What effect, if any, do 1/4 wl buried
ground radials have on the pattern and radiation angle? I normally model
only the vertical portion of a vertical antenna and use the average ground
setting, unless it happens to be on the beach. Can ground buried radials
be modeled?
John KK9A
---------------------------- Original Message ----------------------------
Subject: Vertical Modeling
From: [email protected]
Date: Tue, January 21, 2014 2:41 pm
To: [email protected]
--------------------------------------------------------------------------
What is the proper way to model buried ground radials of a vertical antenna.
_______________________________________________
_______________________________________________
TowerTalk mailing list
[email protected]
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
[email protected]
http://lists.contesting.com/mailman/listinfo/towertalk
|