Another happy testimony for the dissipation theory, and illustration of
the ball, or round surface as pn top pf Tesla and Van de Graf demos. One
dissipates, the other gathers
over its entire surface until a path develops.
And, if single spikes are so efficient, think what hundreds of spikes
accomplish, as in the big rings of "bottle brush" at the top of the big
spherical tanks of natural gas and many other such examples.
Sure wish that water tank had had a few spikes up top.
Press Jones, N8UG, The Wireman, Inc.,
***The friendly "Porcupine" manufacturer***
Landrum, SC, 29356
Sales(800)727-WIRE(9473) or cqwire@juno.com.
Tech help (864)895-4195 or n8ug@juno.com
www.thewireman.com
Our 21st year!
On Mon, 11 May 1998 09:50:31 -0400 "M.G. Brafford"
<brad4@bellatlantic.net> writes:
>After suffering seven lightning strikes in the last two years, I'm
>starting
>to think the "ole ground rod per tower leg" just isn't cutting it
>anymore.
>I remembered a QSO with an American Ham, stationed in Indonesia, about
>lightning strikes. He told me that Indonesia had the highest incident
>of
>strikes of any country in the world. For that reason, he said they had
>to
>come up with some way to protect their installations. He told me a
>large
>percentage of the YB guys use mast's that are made up of solid stock
>milled
>down on the top end to a needle sharp point. The mast has an attatched
>heavy solid copper wire which is dropped down the tower, and connected
>to
>the ground screen. The theory is to bleed down the charge before it
>can
>build to a lethal value. Apparently this workes well for them.
>
>I've been following the Tower Talk discussion about lightning
>protection
>with great interest. Some of the things I plan to do at my station is:
>attatch a milled needle point 3/4" brass or bronze rod to my mast. The
>sharp point will be the highest metalic object for miles on both
>towers. I
>know they are going to take hits, but the tower's take hits anyway.
>I'm
>going to get a grounding company to install a ground ring around my
>towers
>and house. The rings will have a diameter of about 1/3 the tower
>height,
>and will be cad welded to 8' ground rods driven each 16' and tied back
>to
>each tower with 2/0 copper. They will have several 50' long radials in
>a
>spoke pattern with an 8' rod cad welded each 16'. I'm also going to
>use
>several porpuine spikes at various heights on each tower.
>
>The feed lines and control cables are all grounded to the same heavy
>plate,
>and connected to the ground screen. There are no physical connection's
>to
>the rigs during down time. I physically open each cable and reconnect
>it to
>the ground plate 5' away. The AC power is physically opened to my
>shack by
>a breaker box. Also I physically unplug each AC cord.
>
>I'm going to put a porpuine discharge spike on top of my 10' TV
>satellite
>dish, and each clothes line pole. Also I'm driving an 8' ground rod
>near my
>propane tank, and placing a needle sharp lightning rod 10' above it.
>
>Of course I'm protecting my TV installation in much the same way.
>
>With all this wild "el nino" weather one has to use the "here I am,
>come
>and hit me" approach. It's gonna hit anyway, might as well give it an
>easy
>path..
>
>Did I miss anything?
>
>73, Mick W4YV
>
>ps/ As reported on WDBJ ch 7 TV in Roanoke, VA. ;A water tower in Lee
>County, VA had a direct lightning strike last Friday night. The Tank
>exploded and dumped 400,000 gallons of water on houses below, then
>collapsed in a twisted pile of metal. Lightning is serious stuff!
>Don't
>take it lightly!
>
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