"Private" wrote in message
om...
Hello,

I am looking for some advice on if the ground system featured below is
sufficent or should be upgraded. It consists of:

- 3 ground rods 10' each around the tower (bonded together)

Lightning likes to go straight. Try to have at least one ground rod
connected to the tower base at the base; the rod should be directly under
the base or as close to touching the base as possible. A 10' ground rod is
good if in conductive earth. In sandy Florida, where I tood several hits, it
took over a 20' length of ground rod (1/2" steel water pipe) to hit
conductive "hard pan". I just washed it in until it hit some solid clay,
and then washed it into the clay as far as I could.

- 2 ground plates (one outside, one in the shack, also bonded
together)
- lightning arrestors and/or feedthrough adapters
- tower to mast ground - interior coax switch (not shown)

The coax switch should be a grounding switch. Floating elements on an
antenna could actally attract a lightning hit. Also, for induced hits (not a
direct strike, but with enough voltage to damage equipment due to a nearby
strike), the grounding of the antenna lines gives the charge a nice safe
path to follow. That's better than letting the current find its own path by
arcing somewhere. I like to turn off the AC power to my entire equipment
setup when not in use. So, with the power switch on the transceiver and the
main "shack" ac power switches off, a lightning surge on the power line can
only get me or the equipment when I am actually operating. One last
suggestion: put a big (3 or 4' diameter) vertical loop (preferably near the
ground) in all tower cables going into the house. (Right over your ground
plate might be a good place.) The inductance of the loop, and the fact that
lighting likes to ionize paths in a more or less straight lines, will keep
the main current surge of a direct hit from entering your house and finding
its "home" in your power line or telephone line. I survived operating for
many years in the lightning belt of Florida and have the burn marks on my
mast to prove it. The only known damage in Florida was some induced power
that killed a couple of ICs connected to a printer ribbon cable. That was
just from the current going down the tower on the outside side of the wall.
Lightning protection is still as much art as science, Lloyd - but what you
have done so far should fairly well protect folks in the house. If lightning
is going to hit, just let it find a nice safe home - and try not to be
operating when it does. HI HI

In Florida, a house one block from us burned to the ground when lightning
started a fire in their attic. That couldn't have happened at our house, as
the lighting had a 70' tower to hit first, and a 23' ground rod to give the
current a safe place to go. We were hit - several times. So, look at your
well grounded tower as an asset for true lightning protection - not a
liability.

73
ak