Register Account

Login Help

ARRL Propagation Bulletin ARLP008 (2010)

ARLP008 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 8  ARLP008
From Tad Cook, K7RA
Seattle, WA  February 26, 2010
To all radio amateurs 

ARLP008 Propagation de K7RA

Two new sunspot groups -- 1050 and 1051 -- appeared on February 23
and 24.  We've now seen 38 continuous days with sunspots (including
today), and the last time there were no sunspots for two or more
days in a row was back on November 23 through December 8 when we saw
16 days with no sunspots.  If sunspots continue through Sunday (they
will!), February will be the first calendar month since January 2007
with sunspots every day.

Until the past few days, the NOAA/USAF forecast showed solar flux
dipping below 80 around now, which we have not seen since January 26
through February 5, eleven days when the average sunspot number was
16.2.  Note that the average sunspot number reported for the seven
days through Wednesday, February 24 was 23, the previous seven days
was 38.7 and 43.3 the week before that.

The latest forecast (Thursday's, by the time this bulletin is
written) at
shows solar flux at 82 for today, 80 over the weekend, 84 on March
1-4, 85 on March 5-6, and 90 on March 7-13.  But the February 22
forecast showed solar flux below 80 beginning yesterday, February 25
through March 2, going as low as 75 on March 1.

Solar flux is a rough proxy for sunspot numbers, and is measured
with a parabolic dish antenna and a 2.8 GHz receiver tracking the
Sun at the Dominion Radio Astrophysical Observatory near Penticton,
British Columbia -- about 168 miles (271 km) northeast of Seattle.
You can see their daily solar flux data at  They report the flux values three times
per day, but the noon reading at 2000z becomes the official 10.7 cm
solar flux reported for the day, and it is shown in the fluxobsflux
column.  When we see it later from NOAA at the value is rounded
off to the nearest whole number.  For some reason we find solar flux
predictions but no forecasts of sunspot numbers.

The latest NOAA/USAF forecast shows a small rise in geomagnetic
activity, with planetary A index for February 26 through March 5 of
5, 6, 7, 7, 7, 6, 5 and 5.

Geophysical Institute Prague predicts quiet conditions for February
26-27, February 28 through March 1 active, March 2 unsettled, and
March 3-4 quiet.

We had many reports on 10 and 12 meter propagation over the past ten
days.  Jon Jones, N0JK of Wichita, Kansas reported working TX4T
(Tahiti, or French Polynesia, same as FO prefix) on 28.49 MHz SSB
with 100 watts and a 20 foot high random length wire at 1932z on
February 15.  The DX station was way over S9.

Later he worked KH7Y on the east side of the Big Island of Hawaii,
and then Brazil and Argentina.  See for a
photo of the KH7Y tower and for a photo
of KH7Y in his shack with visitor K5SL.  Click on both photos to

Jon notes that is a good source for info on
the TX4T expedition.  In a later email he noted that 10 meters was
in great shape for the ARRL DX CW Contest, and he sent a sound clip
of another contact with TX4T on 28.012 MHz CW at 2210z on February
21.  The sound clip has TX4T blasting through.

Ken Bourke, N6UN operates a 10 meter beacon running 5 watts in San
Diego. He received his first reports in over a year from Idaho and
Louisiana this week, both reporting strong signals.  See

Another 10 meter report came from Charles Lewis, KY4P, who lives in
the mountains of Western North Carolina.  On February 21 during the
contest from 2019-2034z he worked four New Zealand stations on 10
meter CW.  They were all S9, and he got them on the first call.  The
only other DX station he could hear was an Argentine station.

Mike Meenan, ND6MM is south of San Francisco and writes, "I thought
I'd have to wait a couple of years to be working Europe and Africa
from here in 6-land with 100 watts and a vertical, but have been
doing so consistently for the past two weeks on 15 meters between
1500-1700 UTC. The higher bands have really come alive, and the
propagation has been pretty consistent, with some days better than
others. I've even logged a couple of new countries (for me)
including 7X4AN (Algeria) on CW and SV2CXI (Greece) on SSB. In the
afternoon, beginning about 2100, there have been nice openings to
the Pacific, which have yielded BX5AA (Taiwan) and 9M6BOB (Sabah,

"12 and 10 have also had solid, though more sporadic, openings to
the Caribbean and South America and later in the day, the Pacific. I
have been playing on Internet ham sites through the doldrums of
winter, but it's still a thrill to work 'em on good old-fashioned

Dick Le Massena, W6KH (W7WVE when I was a kid and he was terrorizing
the Pacific Northwest with his QRO hardware) in a recent online
discussion characterized 1200 watts as "QRP," and noted that last
Saturday night (February 20) the conditions on 40 meters from 9:45
to 10:30 PM local time were "the best I have experienced in 56

Brian Webb, KD6NRP was surprised recently when he loaded a
horizontal loop antenna that he uses on 40-6 meters on 160 meters.
He fed just one side of his open wire line with a tuner, and ran it
against a counterpoise ground.  He was pleased to work stations all
over North America with 100 watts.  At 1345z last Saturday (February
20) he heard TX4T on 1831 KHz with an S5 signal, but could not work

Brian also reminds us of the NWRA site showing effective sunspot
numbers at  These numbers
are generated by combining actual ionospheric data from ionosondes
with 10.7 cm solar flux, rather than by counting sunspots.  It is
nice to see those numbers climbing.

I ran into a discussion on something called the Reverse Beacon
Network, and was referred here:  It
uses the CW Skimmer technology to copy CW, and then puts the
callsign and frequency information from multiple locations on the
web.  There is also an article about this on page 22 of the March
issue of WorldRadio, which you can download free from  Also check page 30
of the same issue for the K9LA propagation column.

Dick Bingham, W7WKR, who lives in a very remote area of Washington
State sent in a link to something he wants to use for putting up
antennas next Field Day:  The video is
quite impressive, although it looks like a possible hazard at eye
level.  Dick wants to try this in place of a slingshot or archery to
sling a line over a high tree branch.

Jack Luoma, W6JAK of Gilroy, California read about ham iPhone apps
in last week's bulletin, and mentioned that the open source Android
OS for cellphones has amateur radio applications as well.

Jack writes, "I have a Motorola Droid (with Android 2.1 OS) which
has a neat little app called Tricorder which has options to display
corona, UV, magnetogram, and visible images of the Sun with current
sunspot number, flare, and RF flux data.  It also has the ability to
measure (locally) acceleration, magnetic flux, sound pressure, RF
(within wireless phone spectrum), and to display GPS satellite
coordinates.  The application interface emulates the Tricorder of
Star Trek fame, including sound effects."

"There are other ham related apps available for Android phones which
provide call sign lookup, propagation conditions, and amateur
satellite pass predictions.  The number of applications being
developed for the Android OS are increasing at a very fast rate."

Thanks, Jack, and I love the high geek-factor of open source OS
married to retro Star Trek technology!  Just be careful and don't
combine it with that transporter-thingy.  The bugs were never worked
out, and it might be possible to materialize inside a solid object,
which would be no fun at all.

Finally, I ran across this listing:
Click on the QSL in the upper right to enlarge it.  Note the blast
resistant suit he is wearing, while he stands next to a tactical
robot.  Now think about his vanity call sign.

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 February 18 through 24 were 17, 23, 19, 17, 14,
31, and 40 with a mean of 23. 10.7 cm flux was 85, 83.7, 83.8, 83.5,
83.7, 84.2, and 82.6 with a mean of 83.8. Estimated planetary A
indices were 4, 3, 1, 1, 4, 2 and 3 with a mean of 2.6. Estimated
mid-latitude A indices were 2, 3, 0, 3, 3, 2 and 2 with a mean of


Instragram     Facebook     Twitter     YouTube     LinkedIn