Dan,
Correct, I measured the currents and wanted to see the pattern
distortion that resulted, after reading concerns about current asymmetry.
Previously, I modeled very simplified towers northwest of the vertical
(3 towers) affect on the pattern and found they were acting as
reflectors and shifting the pattern about 1.2db to favor the southeast.
The radial current asymmetry is a 0.4db influence in the opposite
azimuth. Luck.
Developing a model for the steel building 56' x 70' x 14' is easier now
with not yet tried tools in EZNEC 6. However, how to model a Ufer
perimeter foundation as the ground is tbd for me. Any advice?
Grant KZ1W
PS any chance you are at SeaPac now?
On 6/1/2018 0:54 AM, Dan Maguire wrote:
Grant wrote:
I modeled measured radial current asymmetry by putting a current source in each
radial at the measured value ...
Sounds like Grant wanted to see the pattern distortion caused by
current asymmetry in the radials. Another possibility would be to
include the suspected *cause* of the asymmetry (such as a nearby
tower) in the model and then look at the *modeled* currents in the
radials. To see the currents in the radials you can follow a
suggestion given in the EZNEC Help under "About Sources":
<quote>
Using sources as ammeters or voltmeters
A zero volt voltage source can be used as an ideal current meter to
measure the current at any point in a wire, and a zero ampere current
source can be used to measure the voltage across a small gap. A zero
volt voltage source is effectively a short circuit so can be placed in
a wire without disturbing normal operation. ...
</quote>
Using the very simple EZNEC sample model "Vhfgp.ez" as an example,
here's what you would see after putting a "current meter" at the
inboard end of each radial.
https://postimg.cc/image/6koo9ohtn/
As an alternative, for AutoEZ users you can look at the "Currents" tab
of AutoEZ and place an "Info box" on any desired segment. Like so.
https://postimg.cc/image/4u5n7p057/
Dan, AC6LA
https://ac6la.com/
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