This is what a model of N2WQ's 4-sq might look like, with each of the four
elements in the shape of an "L" (68.5 ft vertical, ~70 ft horizontal) and with
a 90 ft grounded tower in the center.
https://s26.postimg.org/oao5xh9zd/N2_WQ-1.png
As others have said, when all four elements are fed via the hybrid coupler
controller the SWR will be relatively flat and is not a good indication of
array performance. Here's a comparison of the SWR curves for a single element
fed directly (via the RigExpert analyzer) vs all four elements fed via the
control box.
https://s26.postimg.org/v2el0byyx/N2_WQ-2.png
The fact that Rudy reported slightly different SWR values when the controller
was switched to different directions is an indication that the elements are not
perfectly identical, at least in an electrical sense, probably because of
different coupling to other conductive structures in the vicinity, or slightly
different heights above ground for the single "radial", or small differences in
the ground characteristics under each element.
At Rudy's intended design frequency of 3.550 MHz here's what the azimuth,
elevation, and 3D patterns look like. Note that the forward gain is only ~3.9
dBi (should be closer to 5 or 5.5 dBi) and the F/B is only ~18 dB.
https://s26.postimg.org/kpsae95ft/N2_WQ-3.png
The pattern could be improved a bit but that is really not the main problem.
Instead, take a look at the frequency sweep curves for dumped power and azimuth
pattern F/B.
https://s26.postimg.org/c68wghx3d/N2_WQ-4.png
The dumped power minimum is well below the design frequency and the F/B max
(about 26 dB) is well above the design frequency. Those two curves can be
shifted by a) changing the (in isolation) resonant frequency of the elements
and b) placing a shunt reactive component, capacitor or inductor, across port 2
and/or port 3 of the hybrid coupler in the DXE control box.
All of that is explained in the >5th< edition of the ON4UN book. For those in
Rudy's situation of trying to use an off-the-shelf control box with other than
conventional quarter-wave vertical elements, you probably should consider
getting the 5th edition. That edition also has the details of how to include a
hybrid coupler in the model.
Above modeling was done using AutoEZ: http://ac6la.com/autoez.html
For a very detailed example of modeling this kind of 4-sq:
http://ac6la.com/aecollection8.html
Dan, AC6LA
http://ac6la.com
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