[TowerTalk] Static, Lightening, and protection

[Bill Aycock]

I have one MAJOR disagreement with this argument of Davids- One is NOT 
trying to attract lightning to the tower- one is trying to provide an easy 
path to bleed down the charge (opposite in sign to the charge in the cloud) 
in the region around the tower. This should be steady and always available. 
If the charge is reduced and the charge gradient is less, the easiest path 
for the leaders is somewhere else. A high charge gradient is the equivalent 
of a high pressure which needs relief. a strike provides that.
Bill

At 11:46 PM 3/23/2004 +0000, you wrote:

> >
> > The "rules" seem to be like this:
> > If you want to create "umbrella lightning repellent" protection
>situation,
> > the tower should be as high as possible. Roughly it will protect
> > hemisphere with
> > radius of the tower.
>
>The more common 'rule' is that a tower will protect a circle roughly
>equal to its height by attracting lightning to itself from the area.
>Larger or smaller distances are claimed by some authors.  The effect is
>dependent on total height and the peak stroke current among other
>variables.  Low current strokes are known to 'sneak' in the sides and
>actually hit the sides of buildings and towers instead of the top.  This
>is because the streamers from the ground structures are shorter and the
>attraction of the opposite charges on the structure pulls the leader
>closer as it comes down.  High current strokes are less affected by the
>structures and the streamers are much longer going up to meet the
>leader.
>
>
>David Robbins K1TTT
>e-mail: mailto:k1ttt at arrl.net
>web: http://www.k1ttt.net
>AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
>
>
>_______________________________________________
>
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>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>
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Bill Aycock - W4BSG
Woodville, Alabama