Hi Bill,
Glad that my response was useful and sorry for the delayed additional
response.
Your first Q: If I remember, and I was going through LB's tutorial a few
years ago, I redid his tutorial models into the EZNEC version I had at the
time. I honestly can't remember if this was because his tutorial models
didn't work, or I decided to redo them as "extra practice" with EZNEC. At
any rate, they all worked as I expected and I did gain experience in
modeling his examples when I redid them into EZNEC.
Your second Q: I quickly discovered that I needed EZNEC+ for the additional
segments. Modeling real-world antenna, even wire ones, need a lot of
segments. (See my unpublished analysis of a "real" fan dipole at the bottom
of my web page: http://www.qsl.net/w1dyj/. Because this complex dipole
"wound around" my house, it has many wires.) It also allows you to check
the accuracy of the model, as increasing the segments by a factor of two or
three and running the model again will tell you if you have enough segment
granularity in your model. I am currently designing a "simple" 40M vertical
with radials at 10' and am up to 1109 segments to prove to myself that I
know what I am doing... (Modeling the source is the difficult part, and
keeping all segments the same size is challenging.)
I also started modeling antennas many years ago with YO. And I probably
won't sell my programs -- I still have my college texts from 45+ years
ago...
73 -- Larry -- W1DYJ
----- Original Message -----
From: "Bill Cotter" <n4lg@qx.net>
To: "Larry Banks" <larryb.w1dyj@verizon.net>
Sent: Saturday, January 25, 2014 8:25 AM
Subject: Basic Antenna Modeling tutorial - W4RNL
Larry,
Thanks for the thoughtful answers to my question about the tuutorial. I
have been wondering if the materials were somewhat dated since W4RNL
becoming a SK and the price is high for a ten year old product. It seems
that the use of EZnec was an afterthought with NEC being the primary focus
(typical in academia). I had been told that the course was dropped from
ARRL for these reasons.
Q: How does your EZnec work with the W4RNL antenna files?
Q: Do you see an advantage of EXnec+ over the entry level EZnec?
What attracted me to the W4RNL course was the articles that LB had written
for QST over the years. They contained good explanations of the process,
and since I wasn't using NEC, miniNEC or EZnec, the code wasn't important.
Before considering the W4RNL series, I ordered the new book from ARRL
"Antenna Modeling for Beginners" and will compare the contents to the
W4RNL course table of contents.
I have actually done antenna modeling for the past 20yrs using the K6STI
AO, TA and YO programs from Brian Beezley. He was one of the original
Naval scientists (mathematician) to work with the predecessors to NEC. His
modeling applications were an incredible leap forward for the average ham
trying to construct the best monobanders for DX'ing. Unfortunately, Brian
lost interest in the marketing of his tools, and stopped supporting them.
And, they have to run in DOS emulation mode <groan>.
If you take a notion to sell your copy of the modeling courses, drop me a
line. I would be interested in a used copy.
73 es tnx Bill N4LG
At 03:01 PM 1/24/2014, you wrote:
Hi Bill,
I have both tutorials. I bought them to "enhance" my use of EZNEC, which
I have been using for quite a while. (I now use EZNEC5+.)
I got through about half of the first tutorial and found that, although I
was learning some new and subtle stuff, it wasn't really extending my
knowledge in a great way. I still intend to finish it and the second
tutorial "someday," probably when I get to the point where I need more
advanced knowledge for whatever I am modeling.
They are good - up to LB's (SK) typical level and well worth it.
73 -- Larry -- W1DYJ
----- Original Message ----- From: "Bill Cotter" <n4lg@qx.net>
To: <towertalk@contesting.com>
Sent: Friday, January 24, 2014 12:07 PM
Subject: [TowerTalk] Basic Antenna Modeling tutorial - W4RNL
Hi,
I am interested in the L.B Cebik, W4RNL (SK) "Basic Antenna Modeling: A
Hands-On Tutorial" and the "Intermediate Antenna Modeling: A Hands-On
Tutorial". I recall seeing it carried by ARRL, but it is no longer on
their shelves.
Before I make a decision to purchase, I would like to hear your thoughts
and/or experiences with this tutorial. Or, possibly alternatives. I have
purchased EZnec 5.0 and plan to use it with a tutorial.
If you want to keep your comments private, please reply off-list to
n4lg@qx.net
Thanks es 73 Bill N4LG
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