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Re: [TowerTalk] wire antenna question

 To: towertalk@contesting.com Re: [TowerTalk] wire antenna question Steve Hunt Fri, 14 Nov 2008 16:12:31 +0000 mailto:towertalk@contesting.com>
 ```Gerald, I agree that for most "normal" situations minimum VSWR and resonance are coincident. But I have given one example, and there are others, where they are not. The values I quoted were taken from EZNEC VSWR plots, and confirmed in the VK1OD on-line calculator. 73, Steve TexasRF@aol.com wrote: > Steve, when I plug your numbers into a transmission line program I get > these results:283.8 -j23.66 = 5.72 vswr (same as your example). > > 288.2 +j0 = 5.7 vswr which is just slightly lower than example #1 but > illustrates better vswr when j=0. > > I did not look into the 40 +j4 case but in general, real antennas show > a reactance change much greater than a resistance change when they are > in the range of one half wavelength. I would expect a reactance of > maybe 20 ohms (positive) for an increase of 5 ohms in the resistive > value. This would show a vswr of 1.55 which is higher than the 40 +j0 > value of 1.25. > > Perhaps someone can model a dipole to confirm or refute this. > > 73, > Gerald K5GW _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
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