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## Re: [TenTec] NEC, ground, grounds, and radials

 To: Discussion of Ten-Tec Equipment Re: [TenTec] NEC, ground, grounds, and radials Steve Hunt Discussion of Ten-Tec Equipment Sat, 08 Jan 2011 16:14:31 +0000 mailto:tentec@contesting.com>
 ```I see a very significant difference between the "approximate" formula and the one mentioned by Jerry; the former predicts that you can't achieve Zo lower than 87 Ohms, whilst the latter demonstrates that to be false. That seems like a difference which is meaningful. But what are the amateur applications where a move to FEA would be a meaningful improvement over Jerry's formula? I'm struggling to think of any. 73, Steve G3TXQ On 08/01/2011 15:09, Jack Mandelman wrote: > Forget about the formulas! None of the discussed formulas is sufficiently > accurate of the wide ranges of S/d discussed. All are approximations that > are reasonably valid only over their limited domains. > > A much more practical engineering approach would be to apply a finite-element > analysis of LaPlace's equation using the boundary conditions appropriate to > the geometry of interest. For these types of problems a 2-D quasi-static > analysis provides much better accuracy than any formulas presented. > > Jack K1VT > _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec ```
 Current Thread Re: [TenTec] NEC, ground, grounds, and radials, Jack Mandelman Re: [TenTec] NEC, ground, grounds, and radials, Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials, Steve Hunt Re: [TenTec] NEC, ground, grounds, and radials, Jack Mandelman Re: [TenTec] NEC, ground, grounds, and radials, Steve Hunt <= Re: [TenTec] NEC, ground, grounds, and radials, Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials, Jack Mandelman Re: [TenTec] NEC, ground, grounds, and radials, Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials, Jim WA9YSD