On Mon, 07 Feb 2005 08:40:51 -0600, Cecil Moore
wrote:

Buck wrote:
Today I see a lot of antennas preferring above ground radials.

Maybe decoupling the radials from ground lowers ground
losses? :-)


There have been a number of changes in technology theory in the last
30 or so years. When I was a Novice, the vertical antenna
manufacturers provided information about how to use above-ground
radials, but that was typically for a raised antenna such as roof
mounting it. IIRC, the above ground Hustler 4BTV and the Taylor
antennas both had to be lengthened a little to be resonant in the same
place as the ground mount and radials had to be tuned. Reports at
that time were that antenna efficiency was best when the antenna was
ground mounted and had 8-16 radials buried. However, while not
optimum, the minimum ground was to be an 8-foot ground rod at the base
of the antenna. Baluns seemed to be a new technology, I don't recall
the term "ferrite beads", and RF in the shack wasn't a big issue. One
common practice was having a ground rod as close to your rig as
possible and making sure the rig, PS, antenna and everything
electrical near the rig was grounded to the ground rod. Today the
electrical code for homes forbids that due to ground-loops.

Some of these changes take some getting used to. It's a strange
feeling to realize that what you knew for so long is no longer true.




--
73 for now
Buck
N4PGW