On 09 Jan 2014 18:07:45 -0800, <w3ahl@...> wrote:
4. Depending on the type of soil, distance between ground rods, type
of antenna, etc., add 1 or 2 additional ground rods connected with radial
wires. Ground rods are cheap and last a long time (in most soil). The
earth isn't a very good conductor, especially at >1 MHz. See pdf page 35
in the Polyphaser book.
Also, before installing extra ground rods and tying them together, read up on
proper practice for doing so. I don't remember the exact rule, but multiple
ground rods should be spaced at a specific distance apart, ideally in a ring
around a central rod. For instance (only an example, not necessarily factual
numbers), rods should be spaced a distance apart equal to twice the length of
the rods. It has been years since I dealt with this, so I don't remember the
exact rule. You might find it on the TowerTalk archives. The idea is to spread
the pulse into the ground without saturating it like a single rod might do.
Get to know about Cadwelding to bond the rods together with large conductors.
Gary
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