On Wed, 03 Dec 2003 19:56:06 GMT, Gene Fuller
wrote:

Steve,

Sorry, you are the one who is furthering the lightning rod myth. There is no way
a "true lightning rod" bleeds off enough charge to avoid a strike. That idea
is about 99% urban legend.

I suggest perusal of the Polyphaser web site. There is a lot of good information
there. One relevant comment is:

"The real solution for lightning protection is to have control of the strike
energy. To do this, a well-designed ground system will be a better investment
than cluttering up the top of the tower."


I'd be a bit careful about that statement on a site for a company who
makes their money from attempting to control the energy when
lightening strikes, rather than preventing the strike. There are two
distinct camps. The one that says the solution is to control the
strike and the other says to prevent the strike. Lightening strikes
are unpredictable in most cases, but if you have the tallest structure
around the odds are that it will get hit before lower nearby
structures.

The cluttering refers to a bottlebrush arrangement of multiple sharp points, but
the same idea applies to a single sharp point.

According to our electrical inspector it's not a myth, but I don't
know one way or another. However I do know that it would take little
to bleed a charge and a lot to control a strike. I also know that
every tall structure at the chemical company where I used to work had
lightening rods

Bleeding supposedly does just that. I prevents the charge from
building up to a potential that will help bridge the gap to the
feeders. The last class I had at work on electrical safety was pro
lightening rods AND ground systems. (as was the one for skywarn from
the NWS)

I do use polyphasers and end up replacing one every now and then. My
tower gets hit on average of three times per year. Since the tower
went up there have been no strikes to any home within about 5 lots
from me.

There haven't been any really close strikes that didn't hit the tower.
(of which I am aware). The neighbors are quick to tell me, "Man you
shouldda been home this afternoon when the lightening hit your tower".
That happened in August this year. They were really impressed and
more so in that we had no damage even to the radios which do not get
disconnected.

My antenna ground system has over 600 feet of bare #2 copper wire with
30 grounding rods, not counting the two ground rods for the house
electrical system and the one for the shop. They have separate feeds,
but as my computer network ties it all together, I'm thinking of
bonding the grounds for both services together and to the system
ground. I have visions of a lightening strike to one system and
reaching ground in the other by going through the 130 feet of cat-5
cable. There's a reason I back up everything on CDs and DVDs.

You'll have to fix the return add due to dumb virus checkers, not spam
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com

snip