Roy:

[snip]
"Roy Lewallen" wrote in message
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The bottom line is that I don't trust a single value or its comparison to
36 or 40 ohms as being a reliable indication of efficiency. You either
need to look for convergence of the feedpoint resistance as Peter
proposed, or even better yet, look for convergence of field strength
values at a fixed location as you increase the number of radials.

Roy Lewallen, W7EL
[snip]

That's exactly what I thought.

Since; (a) I don't know my soil characteristics and (b) because of property
limitations that dictate a non-uniform radial field, I felt that all I can
do is to lay down radials in the property area I have avaliable until I see
the change in Zin due to adding more radials become insignificant, then...
I'm done!

I don't really care what the exact value of Zin = Rin + jXin ends up to be,
since there is nothing I can do about it anyway. When I reach the point in
laying down radials to where I can't reduce Zin much by adding more radials,
I will then have the most efficient radial field with the lowest ground
resistance Rg that I can get for my money and effort [smile].

Heh, heh... Money is only money, the effort, hmmm... well that's me crawling
on my hands and knees for hours digging in the dirt (sand) in the blazing
hot Florida sunshine, heat and humidity!

When I arrive at that point in burying radials, I believe that I can then
tune out any reactive part of Zin with my 'tuner' and and end up feeding
power into the remaining resistance Rin which then should be the sum of the
vertical element radiation resistance Rr and whatever value I have ended up
with for ground resistance Rg.

I just won't know what the value of Rr and Rg is, but I will know that I
have achieved the most efficient radial field I could put down here at my
place.

Is this right?

-- Pete k1po
-- Indialantic By-the-Sea, FL

PS: I took your advice and did some reading on simple impedance bridges,
and I saw one that you had designed in one of my ARRL pubs. Cool!

Another idea I came upon that allow the use of those antenna analyzers in a
situation where they can be somewhat immune to BC interference involved a
two step process that went as follows...

(1) Hook up a transmitter through an antenna tuner to the antenna and ground
systems under test and tune the tuner for zero reflected power with a 50 Ohm
reflectometer (VSWR meter). Then (2) disconnect the tuner from the antenna,
and without disturbing the tuner settings, hook a 50 Ohm load to the input
side where the transmitter was connected, and then use the antenna analyzer
to measure the impedance looking back into the output, or antenna terminals,
of the tuner. This impedance should be the conjugate of Zin. Here the
analyzer may not be as affected by potentially strong BC RF signals picked
up by the lengthy antenna element.