Frank, the reason I asked what the efficiency is when using sea water
was to prove your own efficiency calculations.

With sea water the efficiency should be very near to 100 percent. You
get 93% WITHOUT taking the surface wave into account. To make youself
happy you could include the surface wave.

Program Radial_3, with sea water, makes efficiency 98 percent which
I'm confident is near enough correct. Most of the loss is in the HF
resistance of the 14-gauge antenna wire.

================================================== ======

It's beginning to look as though the oft-quoted formula -

Efficiency = Rrad / ( Rrad + Rloss )

is very much in error. This formula is quoted in all the ARRL books
and other learned magazines. I will correct my program to agree
better with NEC4 even though the absolute value of efficiency is not
important and is used only as an indication to maximise effectiveness
of the radial system.

I await your experiments to determine the impedance Zo of ONE radial
wire and the approximate distance at which it occurs.

You can do N = 36 radials at a later date.
Thank you very much.
----
Reg.