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ARRL Propagation Bulletin ARLP023 (2009)

ARLP023 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 23  ARLP023
From Tad Cook, K7RA
Seattle, WA  June 5, 2009
To all radio amateurs 

ARLP023 Propagation de K7RA

It is so great to see some real Cycle 24 sunspot activity this week.
Instead of a phantom that pops into view one day and is gone the
next, we have sunspot 1019, which has persisted for five days, so
far.  Emerging on Sunday, May 31, the resulting daily sunspot
numbers through June 4 are 15, 23, 19, 17 and 17.  This is a Cycle
24 spot, and at high latitude too, which is an indication of a new
cycle spot.

Meanwhile, the low solar wind and quiet geomagnetic conditions
continue.  Currently spot 1019 is about to fade, although it is
still a few days away from crossing the eastern limb to the far
side.  NOAA and the US Air Force expect geomagnetic conditions to
continue to be quiet, and a planetary A index around five is
predicted until June 29.  Predicted solar flux values are 72 for
June 5-6, then 74 on June 7-13.

Geophysical Institute Prague predicts quiet geomagnetic conditions
June 5-8, quiet to unsettled June 9-10, and quiet again June 11.

Time now to look at our 3-month average daily sunspot numbers to
spot trends.  It looks like the numbers are up, slightly.

The three-month average of daily sunspot numbers for January through
April was 2.4, 2.3, 1.5 and 2.  The last number, centered on April,
is the sum of all daily sunspot numbers for March through May,
divided by the number of days.

Since 2007, the 3 month moving average has been:

Jan 07 22.7
Feb 07 18.5
Mar 07 11.2
Apr 07 12.2
May 07 15.8
Jun 07 18.7
Jul 07 15.4
Aug 07 10.2
Sep 07  5.4
Oct 07  3.0
Nov 07  6.9
Dec 07  8.1
Jan 08  8.5
Feb 08  8.4
Mar 08  8.4
Apr 08  8.9
May 08  5.0
Jun 08  3.7
Jul 08  2.0
Aug 08  1.1
Sep 08  2.5
Oct 08  4.5
Nov 08  4.4
Dec 08  3.7
Jan 09  2.3
Feb 09  2.1
Mar 09  1.5
Apr 09  2.0

The average daily sunspot number for just the month of May was 4,
which indicates a nice trend following the March and April 3-month

David Witkowski, W6DTW of San Jose, California was happy to see the
reports of night time 20 meter propagation from N6CAS, and notes
that on May 20 he worked LY1000A (Lithuania) at 0405z, ES1QD in
Estonia at 0612z on May 22, and OH5LF (Finland) at 0635z on May 23.
He worked them all using 100 watts and a vertical antenna.  He
wrote, "I told some friends here in San Jose that I'd worked Europe
barefoot at 11:00pm local time and a few of them gave me the 'Oh
yeah, sure you did' look.  Thanks for vindicating me."

David continued, "Regarding the question of "dead" versus
"unoccupied" bands; I wrote a blog article recently on this topic.
(See During Summer Es I used to listen
to 28.4 and/or tune from 28.3-28.5 to check for openings.  Recently
I made the discovery that listening on CB channel 38-LSB (27.385) is
a much better way to do a quick check for openings; I have monitored
stations from all over the western US burning up "38 lower" well
into late evening, while 10 meters sits idle.  Many times there is
propagation; we're just not using it."

Howard Estes, WB4GUD of Franklin, North Carolina also likes to check
Citizens Band activity for a 10-meter propagation indicator.  He
wrote, "I agree with W1ZI, the bands aren't dead, we're just lazy.
How often do you scan a band, don't hear anything, and go somewhere
else?  I've started checking the CB channels for activity.  If I can
hear the Big Frog Gigger in LA (that's lower Alabama), probably 10M
is open to somewhere."

Mark Lunday, WD4ELG of Hillsborough, North Carolina wrote about a
June 1 E-skip opening on 6 meters that still continued at 0400z on
June 2.  "I worked 12 stations on CW and SSB across the Midwest on
6.  Also, had some multi-hop on 10 meters using WSJT JT65A and heard
Oregon.  Second night in a row that I was hearing Es late at night
on 10 meters using WSJT weak-signal propagation."

Mark said he likes to use DX Sherlock, at

Bill Turner, W4WNT of Matthews, North Carolina has good luck lately
with PSK on 20 meters, even when there are no sunspots.  He is
running 25 watts into a G5RV at 25 feet, and on May 21 at 0345z he
worked Peter, ZL1PWD who reported working 12 stations that day.

Erik Jacobsen, KB9BNY of McHenry, Illinois sent a message titled,
"20-meter PSK31 has been on fire this week."  He wrote, "Tuesday,
with the sunspot number at 19 and the solar flux at 72, 20 meters
nicely opened up for world wide communication.  I participate in the
PSK reporter network (
Basically, when a reporting station receives the de callsign
callsign pattern, the location of the transmitting station is then
plotted on a map.  When I checked the map on Tuesday morning, I saw
a Pakistani station, two New Zealand stations and a Japanese station
plotted.  It just goes to show you how well 20 meters can perform
with a small amount of power (usually under 30 watts), a narrow-band
signal, and relatively modest solar conditions."

He continues, "I preserved the map for historical purposes at Tuesday's total monitoring take for a
24 hour period was 30 countries.  I occasionally blog my PSK
reporter observations at  My current
PSK reporter map can be viewed at"

Thanks, Erik! Great stuff.

Again this week we have a book recommendation.  Bill Scholz, KB1SGY
of Greenwich, Connecticut advises checking out "The Sun Kings; The
Unexpected Tragedy of Richard Carrington and the Tale of How Modern
Astronomy Began."

Bill writes that this is "an engaging book by Stuart Clark that
describes, in great detail, how the great astronomers of the 19th
century linked sun spots, solar flares, auroras and magnetic storms.
An excerpt from the flyleaf: 'In September of 1859, a cloud of
seething gas engulfed the Earth and a blood-red aurora erupted
across the planet.  Around the world, telegraph machines burst into
flames, while compasses reeled as if struck by a massive magnetic
fist.  No one knew what could have released such strange forces upon
the Earth - no one, that is, except the amateur English astronomer
Richard Carrington.'"

He continues, "It's a great read and I recommend it highly if you're
interested in the connection between these phenomena."

Last week's bulletin mentioned a consumer communications product out
of Japan that would require text messengers to learn Morse code.  We
asked if anyone could decode the Japanese in a graphic on a web page
talking about the product, and Brett Graham, VS6BG says it is just a
banner ad for a television show.  He thought the product might be
for real, but checked with JA3USA, who thought it was an April 1
joke.  But Brett says, "The idea does have something going for it."

In last week's bulletin we presented some confusing text regarding
scientific notation and numbers representing the area covered by
sunspots, at least it confused me.  I was worried about it, so I
checked with K9LA, who got me on the right track.  But K1SFA at ARRL
HQ was concerned when she got it from me, so she passed it on to a
ham who is an astronomer for a fact check.  Somehow it got changed
back to the way I had it in the first place, before getting input
from K9LA.  So at this point I can't correct it, although I believe
K9LA had it right.  More later.

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 May 28 through June 3 were 0, 0, 0, 15, 23, 19,
and 17 with a mean of 10.6.  10.7 cm flux was 67.7, 68.2, 68.5,
68.5, 72.5, 71.9, and 72.5 with a mean of 70.  Estimated planetary A
indices were 7, 5, 3, 3, 3, 2 and 4 with a mean of 3.9.  Estimated
mid-latitude A indices were 5, 4, 2, 3, 2, 2 and 4 with a mean of


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