6 Element 20m Beam on 44ft Boom

Designed by Nathan Miller NW3Z

The VSWR is excellent across the band and was set as a high priority during the optimization process. A second model of the tapered antenna was run with double the segments and the results correlate very closely.


The front-to-rear was the top optimization goal. Across the band, the worst case front-to-rear lobe is 25dB.

Gain was sacrificed to achieve the other goals, however it is only slightly less than the 48' antenna. Such a small loss of gain is not even noticeable.

The following table shows the spacing of each element from the reflector, the diameter of each tapered segment and the length of each.

The taper schedule using the DX ENG sizes are as                               
spacing              diameter                                                  
            1.0000    0.8750    0.7500                                         
  0.0000   72.0000   68.0000   75.1943                                         
 99.9100   72.0000   68.0000   66.9345                                         
140.3200   72.0000   68.0000   57.8815                                         
255.2700   72.0000   68.0000   47.3196                                         
320.5900   72.0000   68.0000   45.7244                                         
522.0000   72.0000   68.0000   39.8588