You might want to try YO, AO or EZNEC, where you can plug in actual tubing
sizes and not have to worry about taper correction. I have designed yagis
with all three packages and have had very good results. For me, EZNEC has
been the most accurate for calculating impedance.
GL
John
----- Original Message -----
From: "Doug Snowden" <dougn4ij@gmail.com>
To: <john@kk9a.com>
Cc: <TOWERTALK@contesting.com>
Sent: Tuesday, September 20, 2011 16:29
Subject: Re: [TowerTalk] Yagi mounting and modeling software
I can only think that I have not modeled the taper correctly in mmana...
Doug N4IJ
On Mon, Sep 19, 2011 at 9:22 PM, <john@kk9a.com> wrote:
> The hairpin match only effects the length of the driven element, usually
> it
> is shortened. The other elements should match your model. The Hy-Gain
> bracket may be difficult to model, but I don't see how that would effect
> the
> overall length.
>
> John KK9A
>
>
> To: towertalk@contesting.com
> Subject: [TowerTalk] Yagi mounting and modeling software
> From: Doug Snowden <dougn4ij@gmail.com>
> Date: Mon, 19 Sep 2011 15:00:17 -0500
>
> A recent post made me think of this question. I have been playing with
> the free MMANA modeling software, as well as the older Yagimax. My
> first models were the usual dipole etc. I started playing with yagis,
> and one thing I tried to do was to model a
> Hygain 204ba. I can arrive at decent pattern, f/b, gain etc. All of
> the models I have seen seem to model the HyGain antennas with shorter
> elements than the actual measurements from a Hygain assembly manual.
> The actual measurements are a foot or more longer for, say the
> reflector than the modeled antenna. Other elements are similar in
> difference. The K4VX Yagimax seems to agree with the modeling files I
> see. The ARRL has a ZIP file with all of the HyGain designs. The
> models include the 3 inch boom mounting dimensions too. I have
> changed element tapers. and this does not have anywhere near the
> influence to change the results that I see. I am confused, but, as
> usual, it will be something I have overlooked. Would this have
> something to do with the Beta (hairpin) match that HyGain uses?
>
> Doug, N4IJ
>
>
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