"Please don't get your cart before my horse."
So somebody misunderstands your query and you react like that??
Your post specifically asked about RF grounds. You say the "why" is not
relevant, but it definitely is if you want anyone to have a clue what
the context is for the discussion ... particularly since this forum
deals with towers and antennas and not dummy loads.
Dave AB7E
On 9/9/2021 2:51 PM, Artek Manuals wrote:
Jim et all
One of my heroes of the late 20th century was Ed Demming a noted
statistician ( with a degree in EE of all things) who changed the way
the world (most notably the US and Japan in the 70's and 80's) looked
at and tried to use statistics to solve mass production quality
problems through design of experiments techniques. . One of Ed's
famous sayings was "If you cant say it with numbers..you don't
understand the problem".
So I will say it AGAIN. What I want to do is measure the ground
resistance of a multi ground rod system in VERY POOR soils in my case.
WHY I want to know this number or what I intend to use it for IS NOT
relevant to the discussion at this point. Please don't get your cart
before my horse.
No where in my original query did it indicate that this was for a
vertical antenna system ...but to clarify IT IS NOT. I followed N6LF's
work on measuring soil conductivity and did a lot of measurement to
conclude that my soil is very poor, in the range of .0015. But for the
record laying out radial fields in a jungle with a pure quartz floor
is not really practical and I went to elevated radials a long time ago.
I will happily spend the $10 if N0AX's book ...IF...it talks about
actual measurement techniques for deriving the resistance of a ground
system composed of several ground rods at any given frequency. Those
of you who recommended the book please verify for me that it talks
about actual measurement techniques WHY I want to know is not relevant
to the question.
What I want to do is to be able to describe the problem with numbers
using verifiable measurement techniques at different frequencies.
Maybe I am writing an article for next year's April issue of QST for
building a 50 ohm dummy load using an array ground rods outside my
shack window. Maybe I am just curious.
Dave
NR1DX
On 9/9/2021 2:41 PM, Jim Brown wrote:
On 9/9/2021 9:41 AM, Artek Manuals wrote:
I 've read a lot of articles over the years about ground systems and
how to build a good one. Most of them ignore actual soil conditions
and few talk about the differences between "DC/AC (Low
Freq)/Lightning" and RF ground vs frequency
N0AX's ARRL book on the topic is excellent. Also, these two links may
help. The first addresses grounding and bonding, the second about
radial/countepoise systems for verticals.
http://k9yc.com/GroundingAndAudio.pdf
http://k9yc.com/160MPacificon.pdf
Some important points. The ONLY reasons for an earth connection are
1) lightning safety, and 2) to make certain RX antennas work
(Beverages and some loops. An earth connection has NOTHING to do with
noise reduction, and it does NOT make TX antennas work better. That's
the function of radials/counterpoise.
73, Jim K9YC
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