ARRL

ARRL Propagation Bulletin ARLP054 (2007)

SB PROP @ ARL $ARLP054
ARLP054 Propagation de K7RA

ZCZC AP54
QST de W1AW  
Propagation Forecast Bulletin 54  ARLP054
From Tad Cook, K7RA
Seattle, WA  December 28, 2007
To all radio amateurs 

SB PROP ARL ARLP054
ARLP054 Propagation de K7RA

Last week this bulletin reported sunspot 978 rotating from view.
Now through a process called helioseismic holography, an image of
the Sun's far side shows the spot fading away.  978 was first
visible December 6, and squarely faced earth on December 12.
Perhaps January 2 or 3 we will again see 978 peeking around the
eastern limb, if it hasn't by then faded completely.

No sunspots at all this week, and average daily solar flux was down
over 12 points from the previous week.  Geomagnetic activity was
still low, and down slightly.  Over the next week the planetary A
index is predicted to be 5 on each day, a low number indicating a
stable and quiet geomagnetic field.  Solar flux is expected to stay
around 72 for Dec 28-30, rising to 73 on December 31, 75 for the
first few days of the new year, then up to 80 and 85 by January 4-5.
This indicates an expectation for the return of sunspot 978 or
possibly other sunspots around the same time.

Geophysical Institute Prague predicts quiet geomagnetic conditions
December 28-30, quiet to unsettled December 31, and quiet January
1-3.

Michael Mark, VE4MM was portable /6Y5 December 10-19 from Runaway
Bay, Jamaica when he went to visit a new home built by a friend from
Winnipeg.  Michael brought a 2-element beam, and occupied the top
floor with an ocean view.  He worked all the five bands from 10 to
20 meters, concentrating on 17 meters.  This was during the recent
robust sunspot activity, and it was a real treat experiencing HF
conditions from 18.46 degrees North Latitude, far different from his
home at 49.84 degrees.  He commented, "I made my own conditions on
10 and 12 meters just by calling CQ."  I think he means that when
first tuning the band, it sounded dead, but came to life once
VE4MM/6Y5 was heard.  All together he made almost 1400 contacts,
most of them on 17 meters.

We received more reports of 10 meter surprises, probably due to
sporadic-E, although it doesn't seem the season for it.  Hank
Pfizenmayer, K7HP of Phoenix, Arizona heard "horrible 40-meter noise
wiping out FJ/OH2AM," so he switched to 10 meters to see if he could
pinpoint the source with his beam.  This was well after dark, and
more than six hours after local sunset at 0632-0636z.  He heard
beacons from Kansas, Oklahoma and Missouri.  W0ERE/B in Southwest
Missouri was S9 from 5 watts into a vertical.

This weekend is the Stew Perry Topband DX Challenge, an annual 160
meter CW operating event.  The link,
http://www.jzap.com/k7rat/stew.html given in the ARRL Contest
Calendar doesn't seem to work early Friday morning, although it may
be back by the time you read this.  With no sunspots in sight, and
quiet geomagnetic conditions, a long Winter's night is a great time
for 160 meters.  Try http://www.arrl.org/contests/months/dec.html
for rules, or check out http://tinyurl.com/3dsltv and
http://www.radio-sport.net/stew07_preview.htm for more details.

Don't forget Straight Key Night on New Year's Eve.  This runs from
0000-2359z January 1, and is lots of fun, and a nice excuse to
activate some old and classic manual keys.  See,
http://www.arrl.org/contests/rules/2008/skn.html for details.

Next week in the first bulletin of the New Year we will review some
of the numbers, including average sunspot numbers for the whole of
2007.

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 December 20 through 26 were 0, 0, 0, 0, 0, 0 and
0 with a mean of 0.  10.7 cm flux was 72.6, 71, 71.5, 71.4, 71.4,
72, and 72.6 with a mean of 71.8.  Estimated planetary A indices
were 12, 11, 7, 6, 2, 2 and 2 with a mean of 6.  Estimated
mid-latitude A indices were 10, 9, 7, 4, 1, 2 and 1, with a mean of
4.9.
NNNN
/EX