[Elecraft] Lightning "protection"

[Tom & Barb Valosin]

Essentially, your antenna is a lightning rod. Lightning rods don't 
"attract" lightning. The dissipate the charge differential between the 
cloud and earth before the charge builds sufficiently to provide a path 
for a "leader" charge from earth to the cloud. When a "leader" is 
established, the "full charge" of a lightning strike develops. All this 
assumes a properly installed system. If you are actually utilizing a 
lightning rod system, it must be properly installed. This means solidly 
done interconnections between rods and a properly installed heavy wire 
ground. To further provide some protection, 8 foot ground rods should be 
installed about every 10 feet around the perimeter of the building. 
These rods should be bonded together. Ideally, one would use copper 
strapping about an inch in width. That is expensive. Another possibility 
is the heavy wire used by welders. The perimeter ground should be 
connected to the buildings electrical service ground. Then, there should 
be a minimum 8 foot long ground rod connected with that welding wire to 
each leg of the tower. At guy wire anchors, ground the guy, again with 8 
foot rods. Now, bond each guy-point to one another, to the tower and to 
the perimeter ground at the structure housing the shack. Yes, it is a 
lot of work. This is the type of installation used at the 55KW TV 
station at which I was engineer many moons ago. 750 foot tower. The 
safest place in a thunderstorm was in the transmitter building. The 
properly installed system provided a "cone of protection" for a distance 
of 750 feet around the base of the tower. Much of this info was provided 
by an outfit called Lincole (if I recall the company name correctly) in 
a 2 day seminar that all the station engineers had to attend. Tom, WB2KLD