"itoldyouiamnotiamnotgeorge" wrote
in message ...
"Jim Hampton" wrote in news:wk4yc.5577$HL5.1283
@news02.roc.ny:
MUF has no bearing on sporadic e propogation. Sporadic e will appear
as
high as 144 MHz.
Best regards from Rochester, NY
Jim
Jim, you have been hanging with the Cbers too long the MUF does have a
bearing on sporadic e in fact it plays a major part, doesn't sound like
you know what it means by your reply.
"Phenomena related to Sporadic E"
Other closely related propagation modes are sometimes confused with
temperate-zone sporadic-E. Long duration meteor scatter is often
difficult to distinguish from true sporadic-E. When the MUF is just below
50MHz, for example, random meteors may elevate the MUF to a useful level
for a few tens of seconds at a time. At times, such scatter simply
evolves into solid sporadic-E propagation and may serve as an early
warning of E-skip conditions. During especially intense sporadic-E
sessions, back-scatter may be evident. Back-scatter signals are much
weaker than normal E-skip signals; they may exhibit multipath flutter (a
hollow, from-the-bottom-of-a-barrel sound) or have a slight echo. Back-
scatter signal paths are usually well off expected great-circle bearings,
but focus on known sporadic-E reflection centers. The expected
communication range via back-scatter is short (in the 300 to 1100km
range); thus, back-scatter may be useful for making contacts between the
normal tropo distance and the shortest E-skip distances. Back-scatter
contacts maybe especially useful in "filling n" grid-square multipliers
on 50MHz during contests, for example. Back-scatter has been observed on
144 MHz when the MUF was in that range.
This classical analysis works well in many practical applications, and
it has enabled many alert operators to anticipate 144 and 220MHz
sporadic-E. It may also be helpful to keep in mind that the sporadic-E
MUF often climbs very rapidly, but reaches 144MHz only one-tenth as often
as 50 MHz.
Correct, but I was thinking in the terms of what is published concerning
future 'estimated' MUF, in which case they are looking for F layer
reflection. Heck, if you consider the moon, 24 GHz has been successfully
used - but I wouldn't consider 24 GHz as the MUF. The original post was
stating that 11 meters (or 10) was dead. The consideration is that the
sunspot cycle is in such decline that, normally, F layer propagation won't
be available. My response was that sporadic e does exist - but not
everywhere at once. The bands do open, despite the MUF being far lower in
frequency. I get the feeling that you are simply trying to say I'm wrong; I
was simply speaking out against the generalities.
Best regards from Rochester, NY
Jim
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