|
|
|
|
01 December, 2007
ARLP050
Sunspots appeared over several days in the past week. November 24-27
had daily sunspot numbers of 15, 12 and 11. Otherwise, the Sun has been
blank. In the previous reporting period, November 15-21, there were only
two days with sunspots, and the daily sunspot numbers on both days were
13. The result is the average daily sunspot number from the previous reporting
period to the current (November 22-28) reporting period rose from 3.7
to 5.4.
There were no days with geomagnetic storms, and geomagnetic conditions
should be quiet over the near term. The next recurring solar wind stream
is expected December 17. Expect more weeks of no sunspots, with occasional
appearances for a few days at a time. The U.S. Air Force predicts a planetary
A index of 5 for the next ten days. For the week, Geophysical Institute
Prague predicts quiet
geomagnetic conditions for today, November 30, quiet to unsettled December
1, and back to quiet conditions for December 2-6.
This weekend is the ARRL 160 Meter Contest, which begins today at 2200z.
This is a CW only contest, and you can study the rules at, http://www.arrl.org/contests/rules/2007/160-meters.html.
Check out a resource for 160 meter propagation in the Northern Hemisphere
at, http://solar.spacew.com/www/
160pred.html. This is from the same folks who publish the Proplab-Pro
HF Radio Propagation Laboratory software. They say version 3.0 is radically
updated, and will be released this week, on Monday, December 3. Unlike
W6ELprop and some other propagation software, this one is not free, and
in
fact is likely the most expensive propagation software that hams will
run across. But it looks like a powerful program.
Another one that is quite powerful is ACE-HF, with info at,
http://acehf.com. ACE stands
for "Animated Communications
Effectiveness," and it was originally developed for the military
by a non-ham, who was able to obtain licensing for it upon retirement.
Tomas Hood, NW7US, who writes the monthly propagation column for CQ Magazine
has a page devoted to it on his personal web site at,
http://hfradio.org/ace-hf.
There were more reports of interesting 10 meter propagation. In the CQ
World Wide DX Contest on November 25, Doug Charette, W5GA of Wagoner,
Oklahoma reported that he worked V51AS in Namibia around 1700z. Doug uses
a very modest commercial multiband vertical antenna, and heard the African
station at S-5. He was surprised that he didn't hear many South American
stations on 10 meters in the
contest.
Also in the contest, Phil Finkle, K6EID of Marietta, Georgia worked 6W1RW
(Senegal) on 10 meters at 1409z on Saturday. On the same band on Sunday
around 1630z he worked V51AS, D4C (Cape Verde) and 3X5A (Guinea). Walt
Knodle, W7TTE of Bend, Oregon heard V51AS very clearly on Sunday morning
on 10 meters (he didn't say what time), but the opening only lasted about
three minutes. Around the same time he heard LW5EE in Argentina, which
also disappeared shortly.
Fabrizio Valdirosa, an Italian shortwave listener in Rome, reports he
also observed the 12 meter opening on November 21 reported in our extra
post-Thanksgiving Propagation Forecast Bulletin ARLP049. Fabrizio reported
that this was the first time he's heard Mozambique on 12 meters, and could
hear C91R working North American stations.
He wrote, "This opening happened just at the onset of some
geomagnetic activity, as I have seen other times. When the Kp index starts
to go up, we have good openings on the higher bands, usually from Europe
to Africa and South America."
If you would like to make a comment or have a tip for our readers, email
the author at, k7ra@arrl.net.
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/.
Sunspot numbers for November 22 through 28 were 0, 0, 15, 12, 11, 0 and
0 with a mean of 5.4. 10.7 cm flux was 69.7, 70, 71.3, 70.7, 71.5, 71.4,
and 71.2 with a mean of 70.8. Estimated planetary A indices were 13, 10,
12, 11, 8, 4 and 3 with a mean of 8.7. Estimated mid-latitude A indices
were 6, 8, 8, 8, 6, 5 and 3, with a mean of 6.3.
Source: The
American Radio Relay League
•
DX Spots popup
• All propagation
reports can be found at:
http://www.southgatearc.org/propagation
|
|
|
