On Thu, 12 Apr 2007 18:55:30 GMT, Walter Maxwell
wrote:

This new direction of current flow
will not necessarily perfectly circumferential, but will certainly be somewhere between radial and
circumferential.

Hi Walt,

So as BL&H report without too much pain:
at page 760:
"When the earth is of good conductivity,
the current leaves the wires and enters the earth closer to
the antenna than it does when the earth is a poor conductor."

Now, as to your comment
That current is going to flow in the direction of the
lowest resistance.

It is awfully damned hard to beat the least resistance path of copper
over earth. And yet BL&H offer us this observation I requote above.

What will trump a higher resistance path is greater potential
difference and proximity. Note that BL&H are quite specific about
proximity to the antenna, and hence it follows that the separation
between radials is closer there, than further out from the antenna.
Certainly I can find no where to quote this observation of growing
closeness from BL&H for Roy's consideration, but I trust my common
sense of geometry here too, and I will proceed.

BL&H report (without going into the how, or how much):
"From (8) [that formula] we see that the earth
current proper leads the current in the wires
by 90 electrical degrees."
such that at "that" radial distance, there must exist the greatest
circumferential potential difference between the wire and the earth
currents which is clearly mandated by phase. If a potential gradient
along the circumference is greater than that along the radial, and the
distance along the circumference is smaller than the distance along
the radial; then it stands to reason why BL&H even offer to comment
"current leaves the wire."

Current through earth is largely lost to heat although I do have a
fractal antenna that uses earth current to optimize its low angle
launch characteristics.

Ultimately this reduces to the rather pedestrian observation that more
radials closer in serve efficiency - observed and reported by BL&H.

73's
Richard Clark, KB7QHC