On Fri, 18 Apr 2008 10:26:50 -0700, "Al Lorona"
wrote:

This is blowing my mind. What you said about ground loss peaking at some
certain conductivity makes perfect sense but I never thought about it before
as applied to a vertical antenna system like this.

Sure enough, I found a maximum. This is wild. We always think, "The better
the ground, the better the antenna system," but it's not that simple. It's
funny to think that really terrible ground can have an advantage over pretty
good ground.

Hi Al,

There are two sides to this coin and you are only looking at one.

Let's take for example the vaunted superlatives that are often tied to
swamp land, or even planting your antenna farm offshore (ah that
seawater!). There is more loss there than if you planted your antenna
farm on a 100 foot sand dune (think glass).

So, why do so many eyes mist up with the opportunity of being in a
swap or in the ocean? Launch angle.

That same high (lossy) conductivity is also responsible for what is
called the Brewster angle when it comes to vertical antennas. The
higher the conductivity, the lower the Brewster angle, the lower the
launch angle possibilities, the longer out to the first skip - DX!

Longer radials will not lower that Brewster angle unless you extend
them out very far with a lot of them (think of carpeting the soil out
with a copper mesh for several 10s of wavelengths).

So, returning to your comment:
"The better
the ground, the better the antenna system,"
Better ground may subtract power in the near proximity, but better
ground may also boost relative power at low angles. So, you need to
define what is meant by "better" because this is a choice of opposite
alternatives.

73's
Richard Clark, KB7QHC