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Re: Topband: electrical wavelength

To: <topband@contesting.com>
Subject: Re: Topband: electrical wavelength
From: "Tom W8JI" <w8ji@w8ji.com>
Reply-to: Tom W8JI <w8ji@w8ji.com>
Date: Mon, 10 Sep 2012 21:28:46 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Run the numbers and for RG-6 we see that sq root of L/C is good above a
couple hundred kHz.

Dave WX7G

I just ran it in MathCAD and it showed a Zo and Vf slope starting down around 150 kHz, but I assumed the conductors were solid copper. Conductors have to be in the thousands of a inch range thick to cause an HF slope, because skin depth is .00256 inches on 1 MHz for copper.

I cannot understand the HF and higher numbers at all, where it is all pretty much set by the dielectric constant slowing the TEM wave.

I don't even think it would be a practical concern down to 100 kHz or so where copper skin depth is .0081 inches and we might be getting into the steel core, or am I missing something here? :-)

73 Tom


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