[TowerTalk] [Fwd: Protected Land Area]

[Larry Babb]

While I was C.E. at a local NBC affilliate, we had lightning come into 
the building via a satellite dish.  It took out the satellite receiver, 
an audio/video distribution amplifier, put pinholes in the coax every 
foot or so, for the line that ran the length of the building to the news 
department where the satellite feed was routed to the weather graphics 
computer, and finally took out bunches of stuff in that computer.
Interestingly, the 3 meter dish was only about 50 feet from a well 
grounded, 300 ft tower.  Bottom line, lightning doesn't follow well 
established rules.  73 de larry

David Robbins wrote:
> 
> a commonly used first approximation is that a tall structure protects
> a radius equal to its height.  but lightning is very unpredictable and
> can hit objects directly under a taller structure.
> 
> Edward Soriano, M.D., DU1OZ, KB3CNO wrote:
> >
> > Subject:
> >
> > Message-ID: <3593217D.497B@writeme.com>
> > Date: Fri, 26 Jun 1998 12:20:14 +0800
> > From: "Edward Soriano, M.D., DU1OZ, KB3CNO" <du1oz@writeme.com>
> > Reply-To: du1oz@writeme.com
> > X-Mailer: Mozilla 3.03Gold (Win95; I)
> > MIME-Version: 1.0
> > To: towertalk@contesting.com
> > Subject: Protected Land Area
> > Content-Type: text/plain; charset=us-ascii
> > Content-Transfer-Encoding: 7bit
> >
> > Hi!
> >
> > My newly installed 40 foot crank up tower is more or less 280 feet away
> > from a 120 feet tall wood post holding a VHF omni commercial antenna.
> > Will this high structure protect in a way my crank-up from direct
> > lightning hits? or
> >
> > to rephrase the question were there studies done to determine the radius
> > or area of a land that can be safely protected by a single high grounded
> > tower with lightning rod?
> >
> > 73 de Ed
> >
> > Edward Soriano M.D., DU1OZ, KB3CNO
> > Philippine Islands
> >
> > --
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> 
> --
> David Robbins K1TTT (ex KY1H)
> k1ttt@berkshire.net   or   robbins@berkshire.net
> http://www.berkshire.net/~robbins/k1ttt.html
> 
> --
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