[TowerTalk] Re: Lightning ground "Holy Wars"

[Tom Rauch]

> Date:          Fri, 29 May 1998 14:00:11 -0600
> From:          Dave D'Epagnier <DAVED@ctilidar.com>

Hi Dave,

> 	I can Tom. Its a pretty well known fact in the industry that
> ribbon conductors have lower inductance than round wires of the same
> cross sectional area.

> In fact, the inductance of a ribbon of a given
> width is roughly equivalent to the inductance of a round wire with
> diameter equal to that width. In other words a 1" wide ribbon conductor
> would have about the same inductance as a 1" diameter wire!

That has always been my understanding, that inductance is about the 
same if "width" and length is about the same and if the length is 
much greater than the width. 

So a 1" wide strip has about the same inductance as a 1" wide round 
tube, but with the same amount of material a flat strip has 
less inductance because it can be made wider......

However, RF resistance is much less for the round conductor! 
That's because it has more uniform current distribution over the 
surface. With  equal * surface areas *,  a round conductor has much 
less resistance at high frequencies than  a flat conductor.

Somewhere between the two is the best compromise at any given 
frequency. I'm trying to get a feel for what that compromise is.

> 	The equations are:
snip 

Thanks. I'll play with them.
 
 	The reference can be derived from data in Magraw Hill
> Electronics Engineers' Handbook.

Is that the one by Fink? I'll try to get find a copy.

73, Tom W8JI
w8ji.tom@MCIONE.com

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