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Its all gone quiet. Let's stir it up again.
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March 7th 04, 06:58 PM
Richard Clark
Posts: n/a
On Sat, 6 Mar 2004 21:26:26 -0600 (CST),
(Richard Harrison) wrote:
As mud is wet soil, it has Q, but not just one Q value.
Hi Richard,
Well, as usual, Reggie asks more questions than he can field, and too
often those of the "first principles" has him gummed up in areas he so
loudly touts (how many threads does he spin on about the antenna as
transmission line only to have him turn it into a half wave inductor?)
As to the wet soil. a point well taken. If we learn anything from the
experience of the robots now traversing the Martian landscape (and
politely stepping around the issue of the european hulks littering it
nearby), measurements do indeed reveal our planet and its water
constitute a ball of mud in comparison.
Another shortfall of Reggie's mocking tones is when he demands numbers
when he tires of pontifications (I note no numbers from his holiness
of late). As such, we might rely on a book ( -gasp!- ) which serves
these purposes. I would further note that our two greatest
anti-intellectualists share a common trait confounding their heritage
- anglophobia (railing against popular British poets and writers to
clear their spleen it seems). I shan't be poetic with my recitation
however. ;-)
One of the finest books to serve as an RF reference is found with
"TV and Other Receiving Antennas,"
Arnold B. Bailey
It literally delivers its promise offered in its sub-title:
"Theory and Practice"
[do I hear teeth grinding over another American author?]
In regard to my question of the Q of mud, it answers with many, many
examples offered in both numbers and graphical form (Fig. 5-13 which
Richard can confirm and/or amplify).
Here we find the Q of dry soil (which in the comparison to Martian
samples is literally dripping with water) stands at
Q = 1 @ .5MHz
Q = 4 @ 1.5MHz
Q = 40 @ 20MHz
Q = 400 @ 200MHz
The Q of wet soil
Q = 0.1 @ .5MHz
Q = 1 @ 5MHz
Q = 4 @ 20MHz
Q = 40 @ 200MHz
Let's go further because Reggie's divertissimo has been drained of its
entertainment and we really should be getting into real and useful
information instead. The Q of water!
The Q of fresh water
Q = 1 @ .2MHz
Q = 10 @ 2MHz
Q = 100 @ 20MHz
The Q of ocean water
Q = 0.004 @ 1MHz
Q = 0.04 @ 10MHz
Q = 0.4 @ 100MHz
I would suggest many ponder these last two samples as they run
contrary to many myths offered here about conductivity and the
pleasures of an ocean front home and the rationale of DX. I will
leave that as a teaser....
73's
Richard Clark, KB7QHC
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