[BC] Lightning Prevention?????

[Pete Allen]

We've had our system for about 15 years with only one known direct hit since then.  We used to get hit almost every storm and every hit would bring some damage (usually toasted diodes, rectifier stacks and transformers).  When I brought down the old antenna there were a dozen burn holes in the aluminum due to lightning.  The final straw was a storm that gave us 4 direct hits (2 of them while I was in the xmtr shack trying to get things back on again).  It killed both main and aux xmtrs and left us off air for 18 hours. Those hits also fused a 200 pair telco cable that ran up our hill, blew sparks 10' out of a circuit breaker box, and welded a drop ceiling grid in about 20 places.  Thankfully, no fire.

Since installing the array, lightning will still hit a 90' light pole on I-95 about 400 feet away (no damage to us) and occasionally pings a electric pole at the bottom of the hill (power line issues).  The direct hit I mentioned was from a freak fast moving storm that hit our area year and a half ago.  EMF washed over the station, discolored every CRT on in the building and even caused some fiber optic gear to fail, though the xmtr and other gear stayed up.  I do believe that damage would have been much worse without the system.

I've even been outside when a storm was approaching. Just before lightning would strike 5-6 miles away, I would hear a sound similar to a bug zapper from the top of the tower (it let me know it was time to go inside again ? )


Peter J. Allen
Chief Engineer
WRBS 95.1 FM
410.247.4100
410.247.4533 (fax)
pallen at wrbs.com
www.wrbs.com


-----Original Message-----
From: WFIFeng at aol.com [mailto:WFIFeng at aol.com] 
Sent: Wednesday, May 11, 2005 8:24 AM
To: broadcast at radiolists.net
Subject: Re: [BC] Lightning Prevention?????

In a message dated 05/11/2005 01:54:52 AM Eastern Daylight Time, 
georgenicholas at compuserve.com writes:

> I was
>  introduced to the Lightning Master by my tower crew.  It was also a leap of
>  faith by the GM to buy a story about this stuff, that, from a distance,
>  looks like Christmas garland.  That was in early 1990 and I don't recall a
>  burn since then.  Sounds like a commercial for Lightning Master, but I have
>  used ERI and seen Static Cats an others work very well too.

If you have a Van DeGraaf generator, you can easily prove the operation of 
this "porcupine" technology...

Bring a blunt object near the charged sphere. When the voltage builds 
sufficiently, it will arc. (Miniature lightning.) If you hold the object there, it 
will repeatedly arc, as the voltage builds then arcs again in a continuing 
cycle. Now, bring a POINTED object close to the charged sphere. No arcs! You can 
bring the pointy object closer and closer... still no arcs! If you turn off the 
lights, though, you will see Corona Discharge... a faint purple glow, with 
slightly brighter "streaks" emenating from the point.

This is how these "porcupines" work on the towers. Because they have *many* 
points, they provide many paths for the electricity to discharge via the Corona 
Effect, thus dissipating the charge before it builds up enough to arc. 
(Lightning.) Thus, it *prevents* lightning from striking. The only way for this not 
to work, is if the charge builds up too rapidly for the points to dissipate it 
in time, and it is very strong. Then, *BOOM*!!! Ouch. Normally, though, the 
discharge rate is sufficient to keep that from happening.

So, park those "porcupines" on your towers with confidence. :) IMHO, there is 
sufficient evidence to show that they do, indeed, help significantly. Surge 
protection & good grounding should never be skimped upon, though.

Willie...

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