[Top] [All Lists]

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

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] NEC, ground, grounds, and radials
From: Steve Hunt <steve@karinya.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 08 Jan 2011 16:14:31 +0000
List-post: <tentec@contesting.com">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.

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

<Prev in Thread] Current Thread [Next in Thread>