[CQ-Contest] antenna modeling using local terrain

[Stu Phillips]

With respect to K6TU.NET:

You can upload a file generated by any NEC compliant modeling tool that
will generate a type 13 antenna file.  Tools like EZNEC-PRO etc will do
this.  These models will work for both horizontal and vertical antennas.

HOWEVER - HFTA will only model HORIZONTAL antenna over a model terrain
such as that generated from MicroDem or the K6TU.NET terrain profile
generation tools.

HFTA will not model VERTICAL antennas.

NEC-4 in particular will model vertical antennas over real ground and
buried radials.  You can specify different zones around the antenna with
different ground characteristics specified by conductivity and dielectric
constant.  However, even if you measure these, these zones are still
approximations given that ground characteristics vary with both depth and
distance from your vertical antenna.

I don¹t believe that there are any general databases available that have
the measured ground characteristics by location as a parallel to the
Digital Elevation databases that are used for terrain profiles.

HFTASweep will run HFTA to model your horizontal antenna over actual
terrain around your QTH.

There is no equivalent for modeling vertical antennas over your actual
terrain.

Hope this clarifies the Advanced Options on K6TU.NET.

Stu K6TU



On 8/12/16, 2:41 PM, "CQ-Contest on behalf of FritzOAQ"
<cq-contest-bounces at contesting.com on behalf of fritz at k4oaq.com> wrote:

>Hmmm, this page http://k6tu.net/?q=AdvancedOptions seems to imply
>otherwise
>which reads, in part, "... including the option to upload a custom antenna
>model which can be generated from antenna modeling software such as EZNEC
>...". I believe this page is talking abt K6TUs utility HFTASWEEP. Maybe
>it's
>understood that it only works for horz antennas???
>Fritz K4OAQ
>
>-----Original Message-----
>From: john at kk9a.com [mailto:john at kk9a.com]
>Sent: Friday, August 12, 2016 5:21 PM
>To: cq-contest at contesting.com
>Cc: fritz at k4oaq.com
>Subject: re: [CQ-Contest] antenna modeling using local terrain
>
>There is no need to wait, HFTA will not factor in local terrain when
>modeling your Inverted L.  HFTA only works with horizontal antennas. There
>is nothing that I am aware of usable for terrain analysis of verticals.
>
>John KK9A
>
>
>To:	<cq-contest at contesting.com>
>Subject:	[CQ-Contest] antenna modeling using local terrain
>From:	"FritzOAQ" <fritz at k4oaq.com>
>Date:	Fri, 12 Aug 2016 14:03:49 -0400
>
>
>I'm looking for advice in direction to head in acquiring the necessary
>software to model an inv L and other antennas factoring in my local
>terrain.
>I currently have EZNEC v 5.0.62. As far as I can tell I don't see where
>EZNEC can factor in local terrain. I've read abt HFTA and HFTASWEEP at
>k6tu.net & it appears they can do what I want. I'm a little fuzzy on how
>it
>uses a .txt file from EZNEC tho. As best as I can tell to get HFTA, I have
>to buy ARRLs ant book & wait on it to be mailed to me. You'd think that
>with
>them being so progressive with moving contest scores to the Internet that
>they'd have a way to purchase their ant book & software on-line . maybe I
>missed how to do that. (Sorry, I cudn't resist!) So, are there other
>avenues
>to take that will get me there?
>
>73, Fritz K4OAQ
>
>
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