[TowerTalk] Lightning... and pointed rods!

[Michael Tope]

Hi Dave,

Yes, I have often wondered if this sort of thing would be effective
against rain or snow static. BTW, the aircraft static dischargers are
resistive. I am not sure whether this is to limit discharge current or
dissipate energy. It would be interesting to compare an aircraft
discharger with a porcupine in terms of rain or snow static. I don't
seem to recall ever seeing much written about rain/snow static in
the ham literature (its don't think its in any of the exam questions). 

Mike, W4EF....................

----- Original Message ----- 
From: "David Robbins" <k1ttt@berkshire.net>
To: "Michael Tope" <W4EF@dellroy.com>; "TOWER REFLECTOR" <TOWERTALK@contesting.com>
Sent: Friday, October 27, 2000 3:32 AM
Subject: Re: [TowerTalk] Lightning... and pointed rods!


> the effect of aircraft static dischargers is to provide an easy path for static
> on the plane to create corona and bleed off.  note this is a MUCH, MUCH, smaller
> charge than what develops between a cloud and ground since it is only on the
> outside surface of the plane.  the original purpose of these was to provide a
> spot for corona to form other than on the radio antennas where it would disrupt
> communications.  by making an easy spot for corona to form and remove some of
> the charge the electric field gradient around the antennas is kept low enough to
> keep them  from forming corona.  also note that you can't remove all of the
> charge it since it takes some minimun charge to create the corona in the first
> place.
> 
> the experiment i would like to see is for someone to connect and disconnect one
> of those porcupines during an attack of snow static and see if it can prevent
> the noise that disrupts reception... anyone brave (or crazy) enough to try
> that???
> 
> Michael Tope wrote:
> > 
> > Most aircraft in the world are equipped with "static dischargers"
> > which are essentially pointed carbon rods mounted on the wings
> > designed to bleed off charge gently so as to prevent arcing from
> > the fuselage.
> > 
> > The fact that almost every aircraft you can lay your eyes on has
> > a set of these mounted on its wings does tend to lend some
> > credence to the theory behind  the porcupines.
> 
> -- 
> David Robbins K1TTT
> e-mail: mailto://k1ttt@berkshire.net
> web: http://www.berkshire.net/~robbins/k1ttt.html or http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://k1ttt.net
> 


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