[CQ-Contest] Old dog, new trick

[Bill Turner]

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Been a ham quite a while, but learned something new this weekend.  I was
operating the Volta RTTY contest which started at 1200 UTC, and for the first
two hours, propagation was good.  At around 1400, it got very poor and stayed
that way for about two hours, then returned to near normal for a while.  At
about 1800 it got poor again and once again, stayed that way for a while, then
returned to normal.

All this while I was checking the solar flux, A and K-indexes and forecasts for
the next 24 hours but they showed little change.  What's going on here???

To make a long story short, take a look at:

http://dx.qsl.net/propagation/

and scroll down to the chart showing GOES X-ray flux (5 minute data).  Read the
time on the X-axis carefully and you'll see two C-class solar flares, right at
the times when the bands went out.

Now to some folks I suppose this is old hat, but I had not realized how much a
solar X-ray flare could wipe out propagation without affecting the SFI, A or K
indexes, something I will be watching more carefully in the future.  As it says
in the text which introduces the chart, "If the bands seem to go dead all of a
sudden, it is always a good idea to check this chart to see if a large 
flare has
occurred recently."

Ain't that the truth!!  :-)

73, Bill W7TI


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