Friends in Radio Land,
As I watch the postings on the Reflector, I see a growing interest
in Topband propagation but the interest seems misguided, toward
setting up many beacons instead of looking directly for the variables
which affect propagation. Let me offer a few ideas:
Most operators think in terms of global or large-scale variables
that work with HF propagation programs, such as 13-month averages of
sunspot numbers. Erroniously, they often use daily values but that is
a minor transgression. The point is that F-region ionization is the
single variable that is in question in the HF range.
That will not work in the MF range as there is no shortage of ionization
when it comes to propagation. So another variable, not ionization, has
to be found to make propagation predictions. Would you believe VARIABLES?
Down in the MF range, the problem is much more complicated; the neutral
atmosphere is involved. Being a gas, it is described by its temperature,
pressure, and kinetic energy (bulk motion).
Those variables are local and small-scale but can affect the distribution
of ionization by producing changes in propagation by transverse and
longitudinal tilts in ionospheric layers, through the close coupling of
ionization and neutrals by mechanical collisions. So those are the variables
that should be monitored and associated with propagation - good, bad or
indifferent. But they have to be derived from high-altitude observations,
as close to E-layer altitudes as possible. Sea-level observations are of
little value.
This means monitoring stations should be close to where radiosonde WX
data observations are taken daily at 0000 UTC and T, P and wind data
compared with signal strengths of a stable beacon transmitter.
So I would argue the number of beacons is not the point, it is the data
collected on relevant variables.
Any objections?
73,
Bob, NM7M
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