ARRL

ARRL Propagation Bulletin ARLP049 (2008)

SB PROP @ ARL $ARLP049
ARLP049 Propagation de K7RA

ZCZC AP49
QST de W1AW  
Propagation Forecast Bulletin 49  ARLP049
From Tad Cook, K7RA
Seattle, WA  November 26, 2008
To all radio amateurs 

SB PROP ARL ARLP049
ARLP049 Propagation de K7RA

This is an early bulletin for the Thanksgiving holiday, because ARRL
is closed on Friday, the regular day for release of this bulletin.
We plan another brief, regular propagation bulletin on Monday,
December 1, which will contain the propagation numbers in regular
format that normally appear at the end of the bulletin for November
20-26.  On Friday, December 5 the propagation bulletin will be back
on regular schedule at least into spring 2009.

We had our last glimpse of sunspot group 1008 as it was about to
slip over our sun's western horizon on November 18.  No sunspots
have emerged since then, but it seems a reasonable assumption that
we will see more cycle 24 spots, but we do not know when.  There is
a prediction from USAF/NOAA that shows solar flux rising to 70 on
December 8-9, and perhaps this is just tracking a possible
reappearance of the region that birthed sunspot group 1007, which we
saw in the sun's southern hemisphere from October 30 through
November 6.

Tonight high latitude regions may see some aurora, caused by another
solar wind stream from a coronal hole.  But that same USAF/NOAA
forecast mentioned earlier shows a planetary A index of just 12 for
today, dropping to 8 on Thursday, then 5 (a very quiet level) until
December 4-6, when they expect a planetary A index of 8, 15 and 10.
The planetary A index is calculated with data from a collection of
mid-latitude and higher magnetometers around the world, and 12 is a
drop from Tuesday's (November 25) planetary A index of 17, when
aurora was observed in Polar Regions.

Recently geomagnetic conditions have been very, very quiet, as
mentioned in the last bulletin.  At
http://www.swpc.noaa.gov/ftpdir/indices/DGD.txt note the abundance
of zeroes for both A and K index for two weeks through November 24,
with the exception of November 16.

Milan Cerny, OK3AA of the Czech Republic is QSL manager for Josef
Archman, ET3JA in Addis Ababa Ethiopia. Milan says that Josef is on
20 meters PSK sporadically from 0600-1600z.  With no sunspots,
stations in the Northeast United States and Southeast Canada should
have a good shot during the last couple of hours in that period on
20 meters.

Australian and New Zealand stations my find a workable path with
stronger signals into Australia starting around 1200z and New
Zealand an hour later.  Stations in and around India should see
excellent signals until 1200z.  Milan should see excellent
conditions over the whole 0600-1600z period, with strongest signals
at the beginning and end of that period.  Weakest signals should be
around 0800-1100z.

In the last bulletin ARLP048 we mentioned Jim Borowski's (K9TF of
West Allis, Wisconsin) request for information on propagation
prediction software for the Apple Macintosh.

David Olsen, VK4FOLO (not a typographical error) suggested DX
Toolbox (http://www.blackcatsystems.com/software/dxtoolbox.html)
from Black Cat Systems, which works with both Mac and PC.  If you
click on the screenshots link at the bottom of the page, you can see
some of the prediction screens, including the maps that show
propagation conditions in all directions from your location, varying
by the hour.  It isn't free software, but you can download a trial
version.

David also has his own web site devoted to his ham station at
http://www.djolsen.com/ham/vk4folo.html, and if you back up on that
URL to delete everything to the right of .com, you can see what else
David does in the Australian Outback.

Stew, N7NRA mentioned that recent Mac models with Intel processors
can run Windows in a separate partition, allowing the user to run
W6ELprop or other programs for the PC.

Joe Large, W6CQZ of Alameda, California in San Francisco's East Bay
also likes DX Toolbox, and points out that the Mac Ham Radio
Software site at http://www.machamradio.com/software/software.html
has references to amateur radio software for Mac users.

Look for more reader comments this coming Monday, December 1 in the
next bulletin concerning recent propagation and those 6 and 10 meter
antennas mentioned in the last bulletin.

Have a happy Thanksgiving.

For more information concerning radio propagation, see the ARRL
Technical Information Service at
http://www.arrl.org/tis/info/propagation.html.  For a detailed
explanation of the numbers used in this bulletin, see
http://www.arrl.org/tis/info/k9la-prop.html.  An archive of past
propagation bulletins is at http://www.arrl.org/w1aw/prop/.

Monthly propagation charts between four USA regions and twelve
overseas locations are at http://www.arrl.org/qst/propcharts/.

Instructions for starting or ending email distribution of this
bulletin are at http://www.arrl.org/w1aw.html#email.
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