> conflicting. If I ran the bond outside my building, it
would need to be at least 100 ft
> long and require a lot of trenching. Inside the building
( basement) adjacent to the
> grounding blocks, it could be as short as about 30 ft. At
1 MHz (the approximate
> peak of lightning energy per IEEE) there's a big
difference in the inductive
> reactance. What's a mother to do?
Jim,
I ran 3- 4" wide flashing from my shack entrance ground to
the utility ground in a bee-line under the house. Nothing
else gets within 1/2 inch of that flashing and there are NO
joints under the house. I have a halo ring (flexible copper
tubing) outside the house that bonds everything also.
Mine seems to work just fine for tying things together. All
the telco lines in the shack including dual 24 hour ISDN
connections, FAX/dial-up, and two telephone numbers route to
equipment in the shack, and I have never lost a modem or
anything else.
This is with as much as 3/4 mile spread in the termination
points of incoming RF cables at the shack entrance point and
the big towers, so I probably have a worse case common mode
problem. As a matter of fact the suspected positive charge
lightning bolt I took in an ice storm had so much common
mode current between the tower and power lines it melted the
shields of cables and melted a few telco wires between my
house and the pole, but nothing inside failed except a
2N3904 transistor and diode on a single wire line that went
outside to a 200 ft tower switching relay.
Amplifiers and radios, and even my ISDN and dial-up modems
all lived. Of course every CRT in the house and shop
magnetized, and my dog who was under my operating table
pee'd on the carpet and refuses to set foot in the radio
room any more.
73 Tom
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