ARRL Propagation Bulletin ARLP019 (2009)

ARLP019 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 19  ARLP019
From Tad Cook, K7RA
Seattle, WA  May 8, 2009
To all radio amateurs 

ARLP019 Propagation de K7RA

A cycle 23 spot appeared for two days, April 29-30, in an area that
soon rotated out of view.  Sunspot numbers were 15 and 12, but for
the last seven days we've seen no spots.  This may end soon, and we
get the advance word because of the STEREO mission, which is
gradually able to see more and more of the sun not visible from
earth.  See the current position of the two STEREO satellites at

On May 5-6 the STEREO B satellite was able to see an eruption from
an active region around the eastern edge of the sun, outside of our
view.  If sunspots emerge, they will be cycle 24 spots because of
their relatively high latitude.

Tuesday morning, May 5, Red Haines, WO0W (his call is easy to
confuse.  It is W-Oh-Zero-W) of La Crescent, Minnesota (SE part of
the state, across the Mississippi River from La Crosse, Wisconsin),
wrote that HF conditions had improved over the past few days.  He
noted that he was hearing more of the worldwide NCDXF beacons on
14.100 MHz than recently, and that x-ray flux had also increased.

Red mentioned that x-ray flux (an index of energy from the sun in
the x-ray portion of the spectrum) is a better real-time indicator
of the current state of the ionosphere than daily sunspot numbers or
solar flux.  ''X-ray energy is a primary cause of ionization, which
supports HF propagation'', he wrote.

At you can see the current and recent
x-ray flux.  Click on the graph for a better view.  He noted
significant recent bursts of energy during and after recent sunspot
activity on April 30 and May 1.  You can go to to
see this by clicking on the 20090501_xray.gif link.  Other
interesting dates are January 9-10 and February 10-13, also
accessible from that same page, which includes all of the plots for

The NOAA SWPC page at
has links for a number of useful monitors for x-rays and magnetic
indices, including a D-region absorption prediction for when
conditions get rough.

Red likes to monitor beacons for a real time indicator of
propagation, and he uses a tool called BeaconSee, which creates an
ongoing record of propagation on any HF band.  Download BeaconSee at

David Steels, VE3UZ of London, Ontario has a spreadsheet and graph
showing monthly averages of solar flux values during solar minimums.
He overlaid four solar minimums, lining up start dates for each
cycle, and believes that his curves match a start date of September,
2008 for cycle 24.

E-skip reports continue for 6 and 10 meters.

Last Saturday, May 2, Trent Fleming, KG4ZDM of Germantown, Tennessee
(EM55) worked UT1FG/MM in EL33 and NP4A in FK68 on 6 meters.  He
heard many other stations, but shut down early due to an approaching

Dan Van Orden, N7AQX of Emporia, Kansas had fun on 10 meter CW on
May 3-4.

Dan wrote, ''On 5-3-09, 1642 UTC, AJ4SF responded from Cameron, NC
with a 589 signal strength.  A few minutes later, I tried several
times to connect with KJ4RV.  His signals were down to at least 339
at the time.  Seems strange in that both stations are in the same
vicinity.  Of course antennas and location could have been the

''On 5-4-09, I heard several Low Power Beacon stations from
California.  These beacons are hardly ever heard here in Kansas.
They remained throughout the day.  The band seemed to have gone
west, since no beacons were heard from the Eastern USA.  That in
itself seems kinda strange.  Beacons from Colorado and New Mexico
were also heard, along with the California, Beacons.  Finally worked
K7DRA/5 in El Paso, TX on 10 meter CW and got a 569 signal report.
Looks like the band is changing after months of winter time

Bob Voss, N4CD of Plano, Texas sent in many comments about 10 meters
last weekend, which he said was when the 10-10 club held their CW
and digital contest.  The comments were from people he worked and
from an email reflector.  All reported strong activity on 10.

Vince Varnas, W7FA of Portland, Oregon reported a great 10 meter
opening on Tuesday, May 5.  He wrote, ''Had a pile up of JAs on me
for 1 1/2 hours from 2312-0040 UTC.  Worked 32 JAs before I had to
go to dinner.  Must have left about 5-6 on freq. still calling.
Sigs mostly S-9.  Probably multi-hop Es.  Could have been F2,

Chip Margelli, K7JA of Garden Grove (DM03), California wrote, ''Six
meters has been opening up, marginally, across the Pacific.  K6QXY
was the first to make it across to Man, JL8GFB on May 5th at 2330
UTC.  Three other W6/7 stations made it on that day''.

''Yesterday (May 7 UTC) I had a QSO with Man at 0018 UTC.  Signals
were 559 at the time, and Man peaked at about 579 later.  On the
same day (May 6th here on the West Coast), Johnny KE7V worked 20 JA
stations, and several other Pacific Northwest stations worked
several JAs each.  Here in SoCal, N6KK and N6HC also worked JL8GFB
on the afternoon of May 6th, this was Arnie N6HC's first JA QSO on

''Audio clips of these and other QSOs made by JL8GFB are on his
website at  I run 200 Watts into a
9-element OWA antenna at about 75 feet''.

Thanks, Chip.  OWA means Optimized Wideband Array.  Read more about
it at and

That's all for this week.  Many other emails and subjects left
unreported, but we had to stop somewhere, and this is it.

For more information concerning radio propagation, see the ARRL
Technical Information Service 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 April 30 through May 6 were 12, 0, 0, 0, 0, 0,
and 0 with a mean of 1.7.  10.7 cm flux was 69.4, 68.5, 68.3, 68.6,
68, 68, and 68.7 with a mean of 68.5.  Estimated planetary A indices
were 3, 5, 5, 5, 4, 2 and 6 with a mean of 4.3.  Estimated
mid-latitude A indices were 2, 2, 3, 2, 2, 2 and 6 with a mean of