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ARRL Propagation Bulletin ARLP010 (2006)

ARLP010 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 10  ARLP010
From Tad Cook, K7RA
Seattle, WA  March 10, 2006
To all radio amateurs 

ARLP010 Propagation de K7RA

A big news story this week (big to us, anyway) generated more email
than I've ever received.  If you were one of the kind folks who sent
in an alert about a new prediction for sunspot cycle 24, I'm sorry
that I couldn't get back to everyone.

A new computer model of solar dynamics produced by scientists at the
National Center for Atmospheric Research predicts the next solar
cycle to begin a bit later than earlier believed, but to rise much
higher, perhaps 30-50% higher than the current solar cycle just
ending.  Their model claims to predict cycles 16-23 using earlier
data with 97% accuracy.  I would love to see some dissenting
scientific opinion, but of course in my heart I long for another
cycle 19 of the 1950s, one that I missed.  50% higher would just
about get us there!

You can read about the new prediction model at these sites:  
An article with a photo of Dr. Dikpati and members of her team is

Also check out this article from NASA, which claims that the solar
minimum is already here, or at least the beginning of it:

Regarding current propagation, solar activity is still low, with
many days of zero sunspots recently, and even more ahead.  The
vernal equinox is only a couple of weeks away.  This is a good time
for HF propagation, even with few sunspots, as the southern and
northern hemispheres are equally bathed in the sun's radiation.  
Friday, March 10 could have unsettled to active geomagnetic
conditions, with unsettled conditions on Saturday, quiet to
unsettled on Sunday, and quiet on Monday, March 13.

Bob Poortinga, K9SQL of Bloomington, Indiana wrote in about his
experience on 15 meters last week in the ARRL International DX SSB
Contest.  He ran 100 watts into a wire antenna (he didn't say if it
was a dipole, a rhombic, or a Sterba curtain, but let's assume it
was a simple antenna) and worked 44 countries.  Bob wrote:
''Highlights included 2 JAs (heard 2 others), Tonga, Ascension
Island, and 3 KH6s.  Also heard, but did not work, VK6NS and a ZL1
station.  Had lots of QSOs to South America, mostly Argentina and
Brazil.  The Pacific opening lasted about two hours, occurring about
2130-2330 UTC Sunday.  The 3 KH6s were worked within 15 minutes of
each other and did not hear again''.

Bob also likes the BeaconSee software for monitoring NCDXF/IARU
beacons.  Bob says ''I can't say enough about this program''.  Check
it out for yourself at

Mark Schreiner, NK8Q of Allentown, Pennsylvania wrote in about how
much fun he is having at the bottom of the cycle running QRP, and
how great the lower part of the HF spectrum is with so little solar
activity.  He writes, ''About 1-1/2 hours after local sunrise I heard
3D2NB on 40m on 3/3/06 and once I figured out the QSX I worked him
within a matter of a couple of calls.  I was amazed to hear a
station at such great distance so late after local sunrise!  I had
worked a Fiji Islands station who was barely copyable by me (so I
can't imagine how my signal was for him unless his antenna was
something special) early last summer at about 5 AM during the peak
of grayline, just before my local sunrise, but to work this station
so late after sunrise and with at least an S5 to S7 signal strength
at my end, I thought was absolutely amazing!

And finally, Warren Ziegler, K2ORS holds broadcaster Jean Shepard's
old call.  Warren experiments with longwave transmissions on 137.8
KHz.  Look at the cool stone tower where he operates his station:

Thanks again to the multitude of hams who wrote in about the story
on the next solar cycle, including AI2Q, KB9X, W9DGI, K5SWW, KA7OVQ,
W6AH, K0HZI, AD5FD, W8UI, KC5PJW, K7VV, N7NVP, K0AMZ, N0AX and many

If you would like to make a comment or have a tip for our readers,
email the author at,

For more information concerning radio propagation and an explanation
of the numbers used in this bulletin see the ARRL Technical
Information Service propagation page at,  An archive of past
propagation bulletins is found at,

Sunspot numbers for March 2 through March 8 were 0, 0, 13, 28, 27,
25 and 24 with a mean of 16.7. 10.7 cm flux was 76.1, 75.5, 75,
74.2, 73.6, 74.4, and 72.4, with a mean of 74.5.  Estimated
planetary A indices were 4, 4, 3, 2, 8, 12 and 4 with a mean of 5.3.
Estimated mid-latitude A indices were 4, 2, 1, 1, 8, 6 and 3, with a
mean of 3.6.


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