[TowerTalk] Definition of Ground Screen vs. Radials, Request for Information

[Jan Ditzian]

I have been trying to follow the recent posts concerning ground screens and
radials, but I would not take an oath that I could define the two terms.  I
would appreciate some comment on my understanding of the terms, and perhaps a
better set of definitions.

Radials
I believe that the term "radials" implies wires that are attached to one side of
the feedline at the point where the other side becomes the antenna, such as a
bottom-fed vertical, adn fanning out in some way.  Therefore, I assume that a
vertical dipole usually is not said to have radials, because they would cover
half the antenna.  Radial length is a separate issue, and radials can be any
length, with varying results.

Ground Screen
A "ground screen" is a set of wires, beneath or somewhere near an antenna, not
connected to either side of the feedline at the place where it becomes an
antenna (I am really unsure of this definition).  These wires may be in any
configuration (orientation), and of any length, and perhaps these two variables
will be important in determining the effectiveness of the ground screen.  A
dipole antenna installed near a vertical that has an effective set of ground
radials may see those radials as a ground screen when the dipole is in use.

Counterpoise
W8JI recently used the term "counterpoise," and I would define that as any
conductor connected to one side of the feedline, whether the conductor be
radials, a single wire, a lump of metal, ground stakes, a tuned circuit and
wire, or another antenna, at some point along the feedline to the "antenna" for
which this conductor is supposed to serve as a counterpoise.

I assume that the function of these devices varies, depending on what is
constructed and where it is placed.

Nomex e-mail program is ON.  Flame away, but remember, some Towertalkians may be
under 21.

73,
Jan, KX2A


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