On Wed, Jan 22, 2014 at 8:18 AM, Richard Fry <rfry@adams.net> wrote:
> "The first permanent use of an elevated radial ground system appears to be
> at WPCI, 1490 kHz in Greenville, South Carolina. This installation,
> designed by William A. Culpepper, involved replacing a standard buried
> system with a four wire elevated system consisting of #10 solid copper
> wire, one quarter wave in length, and supported on treated wooden posts
> which keep the radials 4.9 meters above ground.
Careful here. The buried radials were NOT dug up. "Replacing" means moving
the counterpoise connection of the feed system from the buried system to
the elevated system. The presence of 0.4 wavelength buried radials turns
the ground underneath from the typically inferior Carolina medium into a
superior composite medium. Use of four elevated radials **over that
composite medium** is far superior to four elevated over 2-3-4 mS/m.
You said:
"Such characteristics would apply to the use of elevated radial systems by
ham radio operators as well as they do for AM broadcast stations."
Such a statement requires qualification if the basis of the BC experience
includes the previous dense radial field in poor earth **which was not dug
up**, and in all likelihood deliberately left in place by the engineer for
the now well-known enhancement of sparse elevated radials over poor earths.
Why spend a lot of money to dig up the radials? Retire them in place, and
harvest the rewards of a far more conductive composite medium underneath
the raised radials.
I stand by my earlier statements.
73, Guy.
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