Hi Pete,
Maybe...
I have 3pcs 8ft GND rods under my K9AY which I install each winter in my
(puny) 23x28ft backyard.
Going from one to three rods, water them regularly etc. showed me a constant
F/B on AM BC stations between 25 and 42dB ( no S-meter; but s/n differences on
an SDR Perseus)
Interesting though is the relatively high termination values I have to set in
on the K9AY control box; settings 2, 3 or 4 usually offer the best F/B. The
standard advised settings per band would offer 10 to 15 dB less F/B performance.
Knowing that such value alters both the depth and t.o. angle of the backside
lobe it is still interesting to see that it is relatively higher in value than
4 seasons ago when I only had 1 GND rod.
I also tried 4 and 8 radials once ( + a 4ft single GND rod) which did not
perform that well. YMMV.
I have tried this setup at several contest field-day locations on farm-soil
successfully, using a single copper GND-rod 5ft/ 1 inch dia.
**Answering your question; yes, GND can be too good, especially if you cannot
match the optimal termination.
73
Mark PA5MW
-----Original Message-----
From: Topband <topband-bounces@contesting.com> On Behalf Of N4ZR
Sent: Wednesday, October 23, 2019 3:36 AM
To: topband reflector <Topband@contesting.com>
Subject: Topband: Ground under a K9AY Loop
Thanks to everyone who responded to my earlier question about substituting
radials for a ground rod. We just had 3 days of rain - our first in 6 weeks,
so I don't think I have a ground rod driving problem any longer. I'll find out
tomorrow.
But all those suggestions raised an interesting question - is there any such
thing as too good a ground under a K9AY? For example, if I drive an 8-foot
ground rod and then run 4 radials from it, out under and past the elements of
the K9AY, might that be TOO much? It's really not that much extra effort, and
my last lawn mowing for this fall is Thursday.
--
73, Pete N4ZR
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