[TowerTalk] Yagi mounting and modeling software

[Doug Snowden]

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 at 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 at contesting.com
> Subject: [TowerTalk] Yagi mounting and modeling software
> From: Doug Snowden <dougn4ij at 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
>
>