Rick (W-A-one-R-K-T) wrote:

When electrically grounding one's station, is there any particular
advantage of a single 8-foot ground rod over two 4-foot ground rods, or an
8-foot length of heavy gauge wire buried 6-12 inches under the ground?



The easy answer is "it depends".

Where I live, it is virtually impossible to get an 8 foot ground rod in
vertically, without first having someone core-drill the site. Living on
a volcano has it's problems, and one of them certainly is grounding.

Solid rock with perhaps a few feet of earth on top makes for tough
grounding situations. Here, most electrical services are grounded to
something called a "ufer" ground, which is about 20 feet of #6 copper
inside the perimeter foundation and clamped to at least two 20 foot
lengths of rebar, all of which is embedded in the concrete.... external
ground rods (if any) are typically pounded onto the ground at an angle,
so they can follow the interface of the lava and earth. If the
individual is making any pretense of having a vertical rod, they'll bend
it vertical just before it sticks up out of the earth.

Even at 4000 feet elevation, it is rare to see frost on the ground more
than once every 3 to 5 years, so getting a ground below the "frost line"
is easy. When I lived near sea level, I built a workshop of 32' x 52'
and put about a thousand feet of bare copper wire underneath the slab in
a gridded configuration, with all long runs brought to a single point
where the ham shack was to be. It worked great as RF ground and was
tied to the ufer as well, so everything was at the same potential.

Here, multiple short rods would be used (and accepted by the electrical
inspector) for the sercvice entrance ground, if he hadn't already
inspected the ufer ground prior to the concrete pour. (I know someone
that put in the required ufer and poured the slab without getting the
electrical inspection, and had to do just that, add several vertical
rods, all tied together to satisfy the inspector). I've heard rumor
that new code is minimum of 2 each 8 foot rods, but people here aren't
on the newest code level by a long shot.

Best thing is to make sure what local code is first, then go for
overkill if you are at all thinking it isn't enough, especially if you
are putting in a tower and/or worried about lightning.

RF ground is a whole different matter than safety or lightning
grounding, as you are likely aware already.