Since mine is stacked with an 80m dipole I wasn't concerned, but did a
EZNEC Pro4 run 5 to 30Mhz to answer John's question. pdf of plots
available.
At 70' above average ground there is a 36 ohm resonance at 26.8 Mhz with
a 11dbi gain several lobe bowtie pattern off the ends. The current
distribution says it is resonance of the driven element with the loading
from the Moxon tips. The reflector is quiet.
Not very useful but good news since it is probably far enough from other
bands, particularly 15m to not interact much when interlaced.
Grant KZ1W
On 7/27/2017 13:25 PM, john@kk9a.com wrote:
Is the Moxon resonant on any other ham bands in NEC4?
John KK9A
To: StellarCAT <rxdesign@ssvecnet.com>, towertalk@contesting.com
Subject: Re: [TowerTalk] Modeling the Moxon
From: Grant Saviers <grants2@pacbell.net>
Date: Thu, 27 Jul 2017 12:04:22 -0700
My model is the W6NL scratch build 40m Moxon. I obtained different results
using EZNEC Pro4 with the bottom at 70' and top at 140' the peak gain of
either alone is 10.5dbi and 11.0dbi respectively over average real ground.
As a stack the gain is 13.2dbi or 2.2db higher than the 140' alone. This
is in line with other stack modeling I've done and in the range of many
published results re stacking gains, practical and theoretical.
This model's AGT is 1.024 alone or stacked.
My QTH real-time A/B comparison is the Moxon at 91' vs a full size 3L 48'
boom at 140'. The 3L most always wins, lower angle, lower noise with
better F/S and F/B. Not a fair comparison by any means.
Regarding stacking separation, for two high stacks in the modeling I've
done, near 1/2 wl the gain is pretty much asymptotic to its max value.
Grant KZ1W
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