I thought that after a year or so of reading every TT post and the
polyphaser book that I had this figured out. Then someone said
that only the first few inches of ground rod made any difference
to RF and it is better to bury the ground rod horizontally a few
inches below ground. From this I gather that lightning protection
requires long vertical ground rods while RF grounding is better
with shallow, horizontal ground conductors. Did I get this right?
Here's my situation.
Lightning isn't much of an issue in Vancouver. One or two storms
a year.
Just built new shack in the basement. I have a 3" wide length of
sheet copper (24 or 26 ga. Not sure but can find out.) which runs
from inside the shack, right through the wall to the outside. It
comes out about a foot above ground and sticks out of the wall
about 2 feet.
There is a sidewalk made with interlocking paving stones right
against the wall. The pavers rest on an inch or two of sand which
in turn rests on about 6" of road base. Road base is a mixture of
sand and gravel which, when tamped, compacts to a very stable
layer.
Here's what I'm thinking of doing.
1. Pull up the pavers to create an opening in the sidewalk about
a foot wide and, say, 20 ft long.
2. Dig a trench in this opening deep enough to get, say, 4" below
the road base material.
3. Grind up some of the left over drywall (gypsum board, sheet
rock, or whatever else it may be called) and put it in the
trench. Why? I read somewhere, probably TT, that gypsum helps
retain moisture around the ground conductor.
4. Put 20 ft of copper pipe in the trench, attach it to the
copper ground strap using an appropriate clamp, and cover it with
more gypsum.
4a. Should I use 1/2" or 3/4" pipe?
5. As the copper pipe will run right past the electrical system
ground, tie the two together with copper wire (#4 or #6
stranded). This wire will be below grade, i.e. underneath the
sidewalk.
6. Put the sidewalk back together.
I could put an end cap on one end of the pipe, drill a bunch of
holes in it and attach the other end to a hose bib. Ground
resistance going up? Turn on the tap for a minute or so. Has a
lot of appeal but maybe unnecessary. Easy to do, though.
Anyway, I sure would appreciate comments on this.
TIA for your help
73 de Jim Smith VE7FO
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