160m enthusiasts,
For newcomers to 160m, Paul N1BUG's 11Dec e-mail highlighted one of the
interesting phenomenon related to propagation on 160m. Paul noted that
on December10 "between approximately 2200-2300z, propagation to Europe
was enhanced with some of the strongest signals of the season so far".
Looking at the K-indices shows a very quiet period prior to 10Dec
followed by a jump in the K index early on 10Dec (to essentially 3 for
the rest of the day). This phenomenon (good propagation around the time
the K index takes a jump) has been noted by many (one article that
discussed this is in the Summer 2006 issue of The Low Band Monitor). We
don't have to understand the ionospheric physics behind why this happens
- all we need to do is pay attention to geomagnetic field activity
alerts and be on the band when the K index jumps up. Of course it may
not happen all the time - which is another reason 160m is so fascinating
(and frustrating).
Paul's other observation of his path to JA to the southeast between 2140
and 2150z also points out a long-standing axiom regarding the direction
of extremely long distance propagation on 160m: "southwest at sunrise"
and "southeast at sunset". If you have directional transmit and/or
receive antennas, it's worth paying attention to this. For more info on
this topic, visit http://users.vnet.net/btippett/w4zv.pdf.
Carl K9LA
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