In article ,
Jerseyj wrote:
For years I lived in an apartment and just had antenna's in the attic ,
but now having moved to a house in a few months I'll be putting up a
10-160 wire type antenna in my trees. Given the recent spate of serious
thunderstorms, and the accompanying lightning, I'm a bit concerned about
properly grouding the antenna so that I don't fry the house *smile*.
That's a very good concern to have!
I'd encourage you to consult with a local professional (electrician)
who is familar with your local conditions (weather, soil, electrical,
and legal).
I
know about some articles on the ARRL site, but was wondering if anyone
else had some ideas or pointers on how to practically do this ?
You might find it useful to review the following document:
http://www.radagast.org/~dplatt/hamr...-grounding.pdf
It's probably got more information than you want or need, but some
sections of it could be quite useful in planning your system.
Understanding the requirements of your local electrical code (which is
probably based in large part on the National Electric Code) would also
be a good idea. The text of the NEC isn't available online as far as
I know (it's copyrighted) but I understand that most good libraries
should have a copy.
The basic approach you'd want to take, I believe, is to make sure that
the feedline is well grounded immediately before it enters your
building. You'll probably want to hammer in a new ground rod at this
location, in order to keep the distance between grounding point and
ground to a minimum, and if you do so you should/must install a
heavy-gauge "bonding" wire between this ground rod and your building's
main grounding point (probably at the electrical service entrance).
Installing lightning/surge suppressors of one sort or another in the
feedline at the grounding point would also be a good idea. They might
help shunt away a high-voltage spike, induced by a nearby lighting
strike, which could damage your equipment.
If your shack is not on the first floor, it'd probably be a good idea
for you to run the feedline down the wall to ground level, ground it
there, and then run it to the antenna.
You might want to consider an arrangement in which the antenna
feedline drops down from the feedpoint to ground level, is connected
to a ground rod at that point, and then runs along or through the
ground to your house (use a "direct bury" coax, in this case, to avoid
contamination of the cable by soil moisture and chemicals!). This
could help keep direct- or near-direct-strike current away from your
house.
One of the best things you can do is to have some sort of easy-access
connector coupling, located outside the house (e.g. at the grounding
block). If a storm seems imminent, or any time you won't be using the
rig for a while, disconnect the end of the antenna feedline and toss
it away from the house.
--
Dave Platt AE6EO
Hosting the Jade Warrior home page:
http://www.radagast.org/jade-warrior
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