Hello Tom:
Thanks for your input. Yes, the original question was about
precipitation static. I have never had much of a problem with
precipitation static. Only a lightning strike once about 6 years
ago. If I changed the topic of discussion I apologize. I keyed in on
the reference to noise in general. We don't get much snow in Dallas,
only ice.
Both of the verticals were at DC ground potential unlike yours. The
impedance measurements were taken to get a relative likeness between
the antennas due to the closeness to all the utility infrastructure
and house wiring in the near field of both antennas. My QTH is a
typical city lot for a low band antenna. You might as well toss out
all the text book standards when trying to take local noise
measurements in this environment with a vertical antenna that
listens well in all directions.
You are lucky you can see the interaction between your antenna
500'-600' from a tower at your location. There are not any towers
around here, only half a dozen power line poles with ground wires
running down to a earth ground. I would believe both antennas couple
to these structures in a like manner in the space they are located.
Not much choice for me in this environment. I would think enough
noise to create a receive problem is probably ground wave anyway.
I was talking about noise in general. I provided what I thought was
a comparison between two antennas in a similar environment. One
folded and one not. My antenna farm is very restricted for low band
operation. I would think noise is noise in the near field and 5 to 6
wave lengths on 40m would be about 800'. I bet that in my corrupted
environment the noise would be pretty much uniform for both antennas
at 75 feet apart from any or all directions. I don't believe you
would see much difference in the local noise between the two
antennas with only 75' separation on this lot for a single vertical
antenna. 73, Ed - N5NUG
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