Register Account

Login Help

ARRL Propagation Bulletin ARLP038 (2009)

ARLP038 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 38  ARLP038
From Tad Cook, K7RA
Seattle, WA  September 18, 2009
To all radio amateurs 

ARLP038 Propagation de K7RA

The STEREO mission (Solar TErrestrial RElations Observatory) web
site shows a new display, in which the Sun is visible via an
animated image that rotates to show the whole Sun.  The small
portion on the Sun's far side--which is not yet visible to the
spacecraft--is shown as a dark area.

Currently (early Friday, September 18) the animation shows an
emerging bright spot, just beyond the direct view from Earth.

Check the animation at

The zero degree meridian represents the area closest to Earth,
appearing in the center of the solar disk as viewed from Earth.  The
two 90-degree meridians represent the eastern and western horizon,
and of course the 180 degree meridian is directly opposite Earth's

A full rotation of the Sun relative to Earth takes slightly less
than four weeks.  The bright spot appears around 120 degrees, or 30
degrees short of the eastern limb, and may represent a new sunspot
group.  This would be a wonderful event coinciding with the Autumnal
Equinox, the first day of Fall, which starts next Tuesday afternoon
(September 22) in North America.

Helioseismic readings also show an active region in that area, at 30
degrees south latitude.

Go to to see the
current position of the two craft relative to Earth.  Eventually
they will be 180 degrees relative to each other and 90 degrees
relative to Earth.

Thursday's prediction shows solar flux values at 70 beginning
tomorrow, September 19, and continuing through September 24, then
rising to 72 September 25-28.  We haven't reported a weekly solar
flux average above 70 in this bulletin since Propagation Forecast
Bulletin ARLP020 on May 19, and prior to that there were only four
more weeks above 70 in 2009.

These predictions are from NOAA and the US Air Force, which also
predicts a planetary A index of 8 for September 18, and only 5 from
September 19 to more than a month after.

Geophysical Institute Prague also predicts nothing but quiet
geomagnetic conditions for September 18-24.

Steve Jones, N6SJ of Woodside, California hopes to work FT5GA, the
Glorioso DXpedition.  Glorioso is northwest of Madagascar in the
Indian Ocean at approximately 11.5 degrees south latitude, and 47.33
degrees east longitude.

The expedition is expected to be on the air until October 5, and you
can look at to see who is
currently working them.

From California, this weekend Steve's best bet may be 20 meters from
2100-2330z, and possibly 1600-1700z with lower signals.  If we get
some sunspot activity next week, for the following weekend 20 meters
looks good 1430-1930z, and then 2100-0000z.  15 meters with no
sunspots looks bad for this weekend, but on the following weekend if
there is more solar activity 1900-2130z looks possible.  17 meters
looks very good that following weekend, (September 26) 1630-2300z.

For September 19, 40 meters is possible 0130-0300z, and the
following weekend 2330-0330z, again assuming some solar activity in
the days prior.

If you live in the Southeast United States, based on projections
from Atlanta, your chances look much better than from the West

On both weekends from Atlanta, 40 meters looks good 2230-0230z, and
20 meters on this weekend 1930-2300z, and lasting an hour later on
the next weekend.  15 meters looks promising, assuming some
sunspots, 1530-1900z on the next weekend.

From Ohio, 20 meters looks good both weekends 1900-2300z, and 40
meters 2200-0330z.

Bobby Raymer, N2BR of Cookeville, Tennessee says he enjoys working
distant stations despite lack of solar activity.  Running 100 watts
into a vertical dipole, he usually has better luck with CW than
phone.  On 17 meters on September 9 he worked OJ0B on CW on Market
Reef, and on September 11 using SSB he worked St. Helena Island.  He
said he works more stations outside the USA than stateside.

Dennis Reagin, W7KB of Vail, Arizona was running 10 watts SSB into a
portable vertical antenna on September 6 and enjoyed JA0JHA, getting
an S8 report, XE1REM who said he was 10 dB over S9, DL8OBQ/PJ2 in
Netherlands Antilles, who gave him an S6 report.  He notes he is
having fun and working distant stations with no sunspots, low power,
patience and persistence.

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, see the ARRL
Technical Information Service web page at,  For a detailed
explanation of the numbers used in this bulletin, see  An archive of past
propagation bulletins is at

Monthly propagation charts between four USA regions and twelve
overseas locations are at

Instructions for starting or ending email distribution of this
bulletin are at

Sunspot numbers for September 10 through 16 were 0, 0, 0, 0, 0, 0,
and 0 with a mean of 0.  10.7 cm flux was 69.3, 69.3, 69, 69.1, 69,
69.2, and 68.8 with a mean of 69.1.  Estimated planetary A indices
were 2, 4, 4, 6, 5, 5 and 6 with a mean of 4.6.  Estimated
mid-latitude A indices were 2, 2, 1, 4, 4, 4 and 5 with a mean of


Instragram     Facebook     Twitter     YouTube     LinkedIn