From: "James Moritz" <j.r.moritz@herts.ac.uk>
Organization: University of Hertfordshire
To: rsgb_lf_group@blacksheep.org
Date: Wed, 20 Jun 2001 13:02:08 +0000
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Subject: Re: LF: Re: Protection against lightning
In-reply-to: <3B3084F2.613D4874@usa.net>
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> I wonder what did happen when those brave souls disconnected
> from ground the Decca mast at Puckeridge last year ?? :-)
> 
> 73  Alberto  I2PHD
> 
Dear Alberto, LF group,

I tried this - The Decca ant downlead was provided with a movable 
spark gap with 2 electrodes that could be shorted together when 
not in use. There did not seem to be any sparking when the gap 
was opened and closed. However, the weather was quite damp at 
the time of both expeditions, so probably not much chance for 
static to build up.

I believe static on antennas can be caused by friction with the wind 
blowing past, so does not neccessarily need any thunderstorm 
activity to appear. I remember when flying kites as a yougster, 
getting small shocks off the line sometimes, even with clear skies.  
I also recall that it is an endemic problem with aircraft, which are 
often fitted with pointed discharging electrodes to prevent the 
charge building up excessively.

Cheers, Jim Moritz
73 de M0BMU