The images that follow show the near field Z as a measure of mismatch to 377 Ohms of free space. The coloring shows the contours of SWR averaged through the depth of a half wavelength sided cube. The degree of mismatch has been limited to display the values of 1:3:1 SWR. In other words, Z values outside the range of roughly 120 Ohms to 1200 Ohms are clipped so that extreme values did not drive the graphics presentation. The Blue coloring below corresponds to a SWR of 1.25.
The most remarkable feature of the k2 is how one SWR flare off the lower tip is lost in ground. By simply lifting this 20M Dipole 12 inches causes a stir at that same tip (giving it some relief, no doubt) while the drive point Z wipsaws toward worsening mismatchs to the source. This particular design is very sensitive to ground
download the mathcad file used to generate the images.
download the eznec file used to generate the data.
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The k2 is lifted by 12 inches to pull more fields out of the ground:
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