[Lowfer] Crystal Ball Thinking

[John Davis]

>Of course, Part 15 antennas are very legal on 136 kHz, and
>a guy could divide his time between the two bands, using one antenna. On
the
>other hand, the lure of bigger antennas may be irresistible.


At the risk of raising some sore points yet again, I think that
irresistibility has already been demonstrated on Part 15 in some cases.
What concerns me is that some 136kHz ops may just rationalize the 15m limit
away when they choose to work 1750m for a while.  I can't imagine that being
good for our credibility before the FCC, who (we should remember) cited
accomplishments of Part 15 LowFERs as justification for proposing an LF ham
band.  Let's hope the temptation will be resisted.

>Don't forget that the proposed 136 kHz rules don't allow for unattended
>beacons. I see the 1750 meter stuff as being excellent for propagation
>research, and hope that some of the gang will keep their beacons running.


I second that thought most wholeheartedly!  There is real merit in this
concept.  Micropower propagation is an area with potential for a lot of
fundamental research.

The questions raised in the weather-related thread elsewhere on the
reflector today are just one example.  It'd be great to have a real study*
that explores meteorological effects on transmission systems and on the
earth itself, with enough carefully documented data to be able to
distinguish groundwave propagation variations, hardware losses, and
near-field loss factors from each other, for a given set of weather
conditions.

(* A "real" study, that is, as opposed to a certain notorious paper of
several years ago which attempted to prove a link between atmospheric water
vapor and NDB received signal strength.  To buy the authors' conclusions,
one had to assume that the atmosphere was uniform in all directions from the
receiving site for distances of 300 miles or more, because the water vapor
was measured only at the receiving site.  There was no confirmation over the
duration of the tests that the applicable beacons' transmitter power
remained constant.   The signal strength data were "corrected" by a formula
that included a term representing the water vapor content of the local air.
Not surprisingly, without that "correction factor," the supposed correlation
was a lot less apparent!  Ultimately, the only thing the raw, undoctored
data really showed was that a wet base insulator on an antenna feeding a
high-input-impedance measuring instrument can introduce loss.  Big
surprise.)

But to the topic at hand...the enforced micropower conditions of 1750m make
it ideal for measurement of effects over distances that are large enough to
avoid near-field ambiguities, while eliminating uncertainties of skywave
propagation in the results.  Conversely, skywave DX remains an option for
those wanting to study the effects of space weather on much longer paths.

I suspect 2200m is where the latest-and-greatest-mode crowd and the
transcontinental activists will shift.  It's only natural that such efforts
would benefit from the freedom and power of ham regulations.  But:
old-fashioned, slow, low power beaconing on 1750m, with projects spanning
weeks or months...a straitjacket, or a vista of opportunities?  My money is
on the latter.

73,
John Davis