[TowerTalk] Lightning Protection Components

[Lee Buller]

I just have to get into this thread now....

I was the station manager and engineer for KSDB-FM in Manhattan, KS in the
late 80s and early 90s.  The station was a college station with very little
money, but a lot of dreams.  We managed to have donated to us an old (1965)
translator station out of town.  Three acres of land, a 200 foot tower and a
building.  Yes, FD was fun out there for several years.

We raised enough dough to place a Harris FM1K transmitter and an Optomod-D
with Prism equalizers at the site with a three bay antenna at the top.  A
whole whopping 1.5 KW ERP.  We were hit numerous times by lightening.
Multiple times.  Lighting would hit the guys, the tower, the power pole,
trees...just about everything.  The lightening never destroyed any broadcast
gear, but it sure played havoc with the two meter repeater, the antenna and
the controller.  Replace all of those twice in 30 days.  Thanks for ARRL
insurance.

The tower was sitting on a very high hill overlooking the city.  The hill
was made out of limestone.  The tower had two ground rods.  Really, normal
old 8 foot ground rods.  The installers had welded the #8 copper wire to the
leg of the tower and then used a saddle and clap to attach the wire to the
rod.  Then they brazed the whole thing together.  Well, I went out there to
dig around one of the ground rods and come to find out...it was only 4 foot
long!  Even the power to the building was pooor because of the electrical
grounding.  We had to trench a ground line from the breaker box all the way
back to the pole pig to get stable power.  There was no ground out there at all.

To install a ground, we took a backhoe and dug four holes around the tower
until we got below the rocks into some dirt.  The holes were about 12 foot
deep.  We then installed several groundrods in each hole...using a high
temperature welding device which I cannot remember the name of.  We welded
enough rod together to bring the rod to the top of the hole.  Then we tied
6" flashing from the rods to the base of the tower.  

Doing that...stopped the lighting stikes.  There were none the next year.  I
left the station at that time.

A good ground is always a good idea on a tower.  I think I will go out and
shine up my connections.

Lee
k0wa@southwind.net


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