[Top] [All Lists]

Re: [TowerTalk] tower ground question

To: Gene Smar <>,,, jim Jarvis <>
Subject: Re: [TowerTalk] tower ground question
From: Jim Lux <>
Reply-to: Jim Lux <>
Date: Thu, 29 May 2008 10:09:35 -0400 (EDT)
List-post: <">>

N2EA wrote
>Remember, a 90 degree bend in a ground wire is an inductor, and you  
>want a low impedance
>path for strike current.   I would run that 1.5" strap from each  
>tower leg, with an 18" radius bend,
>over the foundation, and out to each ground rod.

Is there a (probably empirically derived) approximation for the inductance of a 
bend in a wire.  For straight wires, a handy approximation is 1 uH/meter.  For 
a curve, are we basically talking about using a standard single turn coil 
formula, with 1/4 turn?

Some online sites give quick and dirty equations along the lines of L=mu0 * pi 
* radius.. in any case, an inductance around 1 uH for 1m circumference (radius 
= 1/2pi meters.. call it about 6").

This would imply that the 90 degree bend is around 0.25 uH.  At 1 MHz, that's 
an impedance of around an ohm or two.

Jim, W6RMK

TowerTalk mailing list

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