[TowerTalk] Basic Antenna Modeling tutorial - W4RNL
larryb.w1dyj at verizon.net
Sun Jan 26 21:49:59 EST 2014
Glad that my response was useful and sorry for the delayed additional
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 (See my unpublished analysis of a "real" fan dipole at the bottom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
73 -- Larry -- W1DYJ
----- Original Message -----
From: "Bill Cotter" <n4lg at qx.net>
To: "Larry Banks" <larryb.w1dyj at verizon.net>
Sent: Saturday, January 25, 2014 8:25 AM
Subject: Basic Antenna Modeling tutorial - W4RNL
> 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:
>>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 at qx.net>
>>To: <towertalk at contesting.com>
>>Sent: Friday, January 24, 2014 12:07 PM
>>Subject: [TowerTalk] Basic Antenna Modeling tutorial - W4RNL
>>>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
>>>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 at qx.net
>>>Thanks es 73 Bill N4LG
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