Guy Olinger postulated for a while, then wrote:
... Run the four elevated over the radial field. ...
You posted that you have NEC4, Mr Olinger. Why not do that yourself then,
rather than ask someone else to do it for you? Post your results and the
bases for them, as I have done for my NEC4 analysis.
Your credibility will improve if your accurate NEC model results show that
the radiation efficiency of a vertical monopole using four, elevated,
1/4-wave radials when installed concentric with even a perfect set of 120 x
1/4-wave buried radials is significantly better than if those buried radials
were not present (other parameters the same). Let us define significant as
differing by more than 0.5 dB.
The buzz I hear on the grapevine about 4 elevated is that's the remedy for
a radial field gone sour, of course leaving the old radials *retired in
place*.
The grapevine buzz you report about this subject is not worth further
dissemination, as no defensible documentation is available to support its
accuracy.
In any case, monopoles using only several, elevated, 1/4-wave radials have
been used by AM broadcast stations where it was impossible/impractical to
install ANY buried radials -- and those systems performed nearly as well as
if they were driven against a set of 120 x 1/4-wave buried radials (as I
posted previously) -- and they met/exceeded the FCC's minimum "efficiency"
requirements for those AM broadcast antenna systems for that class of
service.
There is no scientific reason why that same result would not apply to ham
operators with monopoles on the 160-meter band using ONLY several, elevated,
1/4-wave radials.
Or possibly even to those hams using monopoles with only an "FCP."
R. Fry
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