On Apr 20, 12:44 am, "Richard" wrote:


One thing: Why are radials so effective? They are not resonant
counterpoises, and from the aspect of surface area in contact with ground,
radials have hardly any surface area that "connects" with "the earth". I can
understand if I put in a 20 foot by 20 foot copper plate flat in the earth
that would "connect" to earth quite well, I mean the measured ohmic
resistance to "the earth" could be quite low. But also capacitive coupling
would be low too. But radials have no real capacitive coupling to "the
earth" neither much surface area in contact with "the earth". So it confuses
me as to why they are so effective.

To put it simply, rather than couple with the earth, they help shield
the antenna
currents from the lossy earth..
IE: Richard Clarks comment..
"The alternative view of radials is that they operate as a shield
against loss."

Thats about what it boils down to...
In fact, I think 60 radials one inch off the ground should be slightly
better
than 60 radials touching the ground, both using bare wire.
But radials that are elevated to any real height should be resonant
for
best results.

BTW, since it looks like many wires in the earth are as good as a plate,
perhaps I could put in a wire mesh grid about 1 foot under the soil over the
whole garden . I'm digging up the garden anyway. Perhaps with some ground
stakes here and there connected to the grid, although maybe not necessary.

Would be ok, but actual radials are a better use of wire, than mesh.
Also
mesh can develop connection problems on down the line.
Mesh has an equal density over it's whole area.
But radials place a higher density of wire at the feedpoint, which is
what you want. The ground area at the feedpoint is the most critical.
But that doesn't mean you want to ignore the area a bit farther out.
Normal radials spoked out from a center give you a good appx overall
density of wire in the areas you want to have it.
In general, for a given amount of wire on the ground, many shorter
radials are better than a few long ones. That places more of the wire
at the feedpoint.
A cylinder or tube, etc makes a lousy rf ground. The lightning ground
is
the one that needs a super good connection to earth.
The RF ground requires *no* connection to earth to function properly.
MK