Sorry. After all the traffic on lightning I thought I would
put in my two-penny worth......
Personally, I have never been pursuaded by the argument that you
should ground ANYTHING for lightning protection. Why attach a nice
healthy fat ground to a tower to ATTRACT the lightning? This
isn't lightning protection - this is lightning ATTRACTION!
See the case of the guy who had his tower hit every time a storm
came by..... saving his nieghbours from being hit!!!!!!!!!
For this reason, I consider anybody who spends time and money
on all this PolyPhaser garbage as wasting their time and money....
As for the base exploding stuff ..... well, most of the towers in
the USA are healthily guyed (you see very few free standing).
With a guyed tower, it's not (or shouldn't be) the BASE that's keeping
the thing up!
The only cracks I've seen in a tower base was when the concrete
dries too quickly in the Sun.....
Finally. Taking a leaf out of the sailing book..... The same
crazy situation exists there. One argument goes that lightning
will hit the mast and if the rigging isn't connected through to
a hull plate, a hole will be blown in the bottom of the boat
as the bolt tries to reach the sea.....
Again, like the exploding base, NO ONE EVERY SEEMS TO BE ABLE TO
SUBSTANTIATE THIS MYTH.....
>From the manual supplied with all boats made by Catalina Yachts:
The merits of grounding the rigging system and ground bonding
are controversial. Many different configurations may exist.
As the merits of this method have not be substantiated Catalina
Yachts manufactures the hull without bonding.
The owner is responsible for fitting ground bonding and any
consequences of so doing..... or words to that effect.
IN OTHER WORDS .... we don't do it because it's not necessary and
if you do do it then whatever happens is YOUR fault (if you
attract lightning to your boat and you're hit, you're responsible!).
I have been at sea with a non-bonded boat (not mine) and lightning
was pitching into the sea EVERYWHERE around us. I still maintain
that we did not get hit in seemingly 100% chances because we
weren't waving a 50' high lightning conductor around!!!!!!!!!
When a lightning bolt lands feet away from you several times
in the space of minutes and you have a 50' metal mast in the
air and you don't get hit, I think that proves the point.......
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Paul Evans, W4/G4BKI firstname.lastname@example.org +1 (813) 874-2980
Fax:+1 (813) 872-8696 Views expressed here are not necessarily |\
those of PacComm. I don't surf the internet, I SAIL IT! /| \
Cptn of S/V "Spindrift" (Catalina 36), Dunedin, FL. / | \
PacComm Packet Radio Systems,Inc., / | \
4413 N.Hesperides St., Tampa, FL 33614-7618 / | \
>From Richard L. King" <email@example.com Wed Jun 21 15:50:00 1995
From: Richard L. King" <firstname.lastname@example.org (Richard L. King)
Subject: Exploding bases
This is second-hand info, but I heard about 15 years ago that the W7KW
station in AZ experienced an exploding base from a lightning hit. I
think I heard this from one of the fellows who went there to take down
his towers when he sold out to one of the TDXS guys (NA5R ???). Was it
K5RC that told me that? Tom used to be on this forum.
Before I appreciated the damage that lightning could do, I had a tower
on the Texas Gulf Coast that was only grounded to 3 ground rods that
were driven into the bottom of the base hole before the concrete was
poured. These ground rods were attached to the tower base inside the
concrete with hose clamps. I took many direct hits there without base
or antenna damage, tho I did lose a rotator control from time to time.
The secret there was the fantastic ground conductivity there. I shunt
fed the tower on 160 and had phased 80 meter verticals with NO RADIALS,
and they all worked superb with just a ground rod.
I will always ground towers outside the base concrete on any future
tower installations that I might do. Speaking of new towers, is there
any good contest station locations still available in the Austin, TX