[ICOM] Grounding

[Ed Senior]

Hi Tom - 

I agree with your conclusion about the desirability 
of heavy, solid ground connections.  

But one of your steps along the way is wrong:  
Inductors in parallel do not "add," unless you're describing 
them in terms of their admittance, rather than impedance.  
The inductance of N parallel inductors each having inductance 
L should be L/N, to a first approximation.  

73, Ed 

----- Original Message ----- 
From: "Tom Norris" <r390a at bellsouth.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Tuesday, May 18, 2004 8:01 AM
Subject: Re: [ICOM] Grounding


> Also remember that in a "lightning ground" or even an
> RF ground system, stranded wire is a no-no. Even
> 4-0 gauge wire. Why? The inductance of the wire.
> Think of each strand as a separate inductor, think
> of multiple inductors in parallel -- inductors in parallel
> *add*, so in a bundle of wire lets say that each
> individual wire presents an inductance of 1 microhenry,
> a bundle would be much more than that. To a lightning
> surge of just a few microseconds, the impedance of that
> length of stranded wire may be many thousands of
> ohms! Always use solid wire, bussbar or copper strap
> if you want a more efficient ground for lighting protection.
> 
> I've put in many dozens of ground systems at remote
> locations over the years, and this theory appears to
> have proven itself true.
> 
> I'm sure I'll be yelled at for being wrong, but at least
> I got the misinformation from various IEEE publications
> and from Polyphaser, so blame them :-).
> 
> Tom NU4G
> 
>