160M DXing and the quasi-static process.
With the ongoing discussion of 1/8 wave verticals and the practical
meaning of a 1db change in signal level, the following may be relevant.
First, however, let me warn everyone on the list that this post is
fairly long and contains no "hot" DX info, nor does it reveal any
hard-hitting technical secrets, so all you hardboiled,
"just-the-facts" cynics should hit the delete key now. But, things
are kind of slow on the reflector at the moment, so maybe reading
this won't waste too much of your valuable time. Some of you will
find what I have to say useful, if only as a source of encouragement.
I can never sit still. I am always looking for ways to improve both
my transmitted signal on topband and my receiving capability. Living
in a small town with a neglected power distribution system makes the
latter task especially difficult.
When it comes to improving my receiving capability, I've come to view
my quest as a quasi-static process. A what? In thermodynamics, the
term "quasi-static process" describes a change that happens
infinitely slowly, but other sciences have applied the term to
processes which occur in increments so small that virtually no
difference can be detected between individual, sequential, discrete
steps within the process.
Two non-scientific illustrations of this come to mind:
(1) On the day that a calf is born, the farm boy picks up the newborn
and walks around the barn, holding the calf. He does this every day.
However, at some point, he can no longer do it. The calf has become
too heavy, but each individual day's change in weight was not
noticeable. If you can lift 100 pounds, you will have no trouble with
102 pounds, etc.
(2) Second example: Biologists will tell you that if you toss a frog
into a pot of scalding water, he will, of course, jump out
immediately. But, if you place a frog in a pot of room-temperature
water and very gradually increase the heat, the frog will sit there
until the hot water kills him. Why? Because, from one moment to the
next, he could tell no difference in the temperature of the water. If
it's OK one minute, the next minute will be fine, too.
What does all this have to do with 160M DXing? Just this:
I am forever making small (sometimes tiny) improvements to my receive
antennas; improving a ground rod here, tweaking a termination
resistor there, installing a better common-mode choke on this feed
line, and on and on. Most of these improvements result in only a
slight increase in overall signal-to-noise ratio - usually less than
1db, perhaps only 0.5db. That is to say each improvement, taken by
itself, is un-noticeable.
So, it follows that as a 1db change in sound level lies right at the
lower threshold of what most listeners are able to perceive as a
change in volume, these small incremental changes (improvements) in
total receiving performance will result in noticeable, measurable,
and useful improvements only in the long term - as the end result of
a continuing, ongoing process of optimization. The effect is cumulative.
Over the past couple of years, I'd be willing to bet that I have made
over twenty such small improvements. If each one is worth only 0.5db,
by now I have improved my signal-to-noise ratio by at least 10db!
The point is that ANY progress is progress, and while only a
dedicated few ops will get up out of their Lay-Z Boys to work on
their Beverage installation for a meager 0.5db improvement, no one
would scoff at a 10db improvement. The work is a long-term
investment. Think of it as an IRA for topband success.
73,
Charles - K5ZK
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