[Hallicrafters] Antenna Lightning Protection

[Bob Macklin]

When I was doing the study for NASA in 83 I was taught that the cone was
about 45deg.

I know that Glen knows where Mt. Lemmon is. When lightning hits something up
there that's not the end of it. There is a lot of granite in that mountain
and when it gets to the surface it goes everywhere!

We got a lot of experience repairing systems after a hit! We had a
powerhouse with 2 naval diesel generators. During the 4 years I was there
the powerhouse got hit twice. That's when we started installing the large
knife switches to disconnect everything. Then we went to the dorm to
hideout!

Bob Macklin
K5MYJ
Kent (Seattle), Wa,
"Real Radios Glow in the Dark"

----- Original Message ----- 
From: "Glen Zook" <gzook at yahoo.com>
To: "Bob Macklin" <macklinbob at msn.com>; <hallicrafters at mailman.qth.net>;
"Carl" <km1h at jeremy.mv.com>
Sent: Wednesday, January 07, 2009 10:22 AM
Subject: Re: [Hallicrafters] Antenna Lightning Protection


> What I have found is that the "cone of protection" is about a radius from
the vertical structure that is about twice that of the vertical structure.
That is, for example, if the vertical structure is 100 feet tall then the
protection radius will be about 200 feet (400 feet diameter).  Now the
actual cone does not have truly straight sides, that is a true cone.  It
more closely resembles a parabolic curve.
>
> Since lightning does not like to obey absolute rules, I have seen
occasions where something that was within what would normally be considered
to be a cone of protection actually hit.  But, a good rule of thumb is that
items are normally protected within the "cone of protection".
>
> Glen, K9STH
>
> Website:  http://k9sth.com
>
>
> --- On Wed, 1/7/09, Carl <km1h at jeremy.mv.com> wrote:
>
> From: Carl <km1h at jeremy.mv.com>
>
> Interesting Bob.  Ive been arguing about the Cone concept for decades but
the established orthodoxy  rebels violently whenever it is mentioned. Ive
left several antenna forums in disgust over this.
>
>
>
> ______________________________________________________________
>