Gray-Hoverman GH4n with NARODs for UHF/VHF-hi


This is the first antenna model of this type that I completed. The hat tilt was a free parameter and it was the optimizer that suggested the top of the hat to be put very close to the reflector plane. So I decided to fix it there from building considerations.

This antenna was optimized with the nec.opt script. The wire used is 1/4 inch diameter 6061-T6 aluminum.
The command I used was:

python -m nec.opt -s(470,15,17) -t(14.5,14.5) -s(174,6,8) -t(8.0,8.0)
-F "max(max_swr_diff, .9*ave_max_gain_diff+.1*ave_gain_diff)" --de-np=100

The two and three NAROD reflectors configurations were created afterwards with the idea of allowing an upgrade from GH4n to GH4n2 or GH4n3



  • Model
  • Horizontal Pattern

The charts and the 3D model are interactive. Position the cursor over a dot or a segment for info. View the model/pattern in full screen for print.


The nec model can be downloaded from here: GH4n, GH4n2, GH4n3, GH4

All Gray-Hoverman designs are covered by GPL v3 or later as stated here.



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Copyright 2010 Nikolay Mladenov.
nikolay dot mladenov at gmail dot com