Dan,
Reading that QRZ.com thread you linked to and reflecting on K4SAV's
measurements and how much they appeared to vary over a fairly short
period of time, got me wondering about what could be responsible. I am
fairly certain that at least part of the radial system for my 160 meter
vertical is over the drain field of the septic system for my cabin. Who
knows, maybe a properly timed toilet flush could make the difference
between working a new one and coming up empty :-)
Okay, the toilet aided pileup busting is a stretch, but seriously, I am
not sure if I can think of any better explanations than septic discharge
for why ground characteristics could change that quickly. I do know in
some cases there can be water table very close to the surface, but I
don't know how much that typically varies over the short term. My only
other thought is that maybe in K4SAV's case the lay of the grass under
the wire is changing slightly over time and the impedance is
super-sensitive to the gap between the antenna and the ground (although
I think K4SAV said that his grass was all dead).
73, Mike W4EF..........
On 3/23/2020 10:18 PM, Dan Maguire via Topband wrote:
Grant wrote:
If you really want to know the parameters, see antennasbyn6lf.com as Rudy
describes techniques for ground RF properties measuring.
Turns out that very subject was being kicked around on a recent qrz.com thread:
https://forums.qrz.com/index.php?threads/indirect-measurement-of-ground-constants-with-a-dipole.696955/
Dan, AC6LA
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