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ARRL Propagation Bulletin ARLP038 (2012)

ARLP038 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 38  ARLP038
From Tad Cook, K7RA
Seattle, WA  September 21, 2012
To all radio amateurs 

ARLP038 Propagation de K7RA

Average daily sunspot numbers dropped this week, from 83.1 in the
September 6-12 week, to 56 in the recent September 13-19 period.
Average daily solar flux declined from 118.9 to 101.4.

The latest forecast shows predicted solar flux at 115 on September
21-22, 120 on September 23-25, then 125 on September 26-27, 130 on
September 28, and 140 on September 29 to October 1. On October 2 it
drops to 135, 130 on October 3-5, 125 on October 6-7, 120 on October
8, and 115 on October 8-9.  Flux values then dip below 100 on
October 14-16, and peak again around 140 on October 25-28.

The predicted planetary A index is 12 on September 21-22, 10 on
September 23 and 5 on September 24-28, 10 again on September 29, 5
on September 30 through October 2, 10 on October 3, 8 on October
4-5, and 5 on October 6-11.

The Czech Propagation Interest Group geomagnetic forecast this week
comes to us from Petr Kolman, OK1MGW. They see quiet to unsettled
geomagnetic activity September 21-22, mostly quiet September 23,
quiet September 24-26, mostly quiet September 27, quiet to unsettled
September 28-29, quiet to active September 30 through October 1,
active to disturbed October 2, quiet to active October 3, quiet to
unsettled October 4-5, quiet October 6-8, and quiet to unsettled
October 9-11.

Carol Milazzo, KP4MD/W6 in Citrus Heights, California wrote in about
WSPR mode for weak signal work on 2 meters.  She says, "California 2
meter WSPR study group stations on 144.4905 MHz can be heard
throughout the state of California from Redding at the north end of
the central valley down to San Diego. Joe Taylor K1JT's WSPR mode
allows stations with modest power and antennas to participate in
weak signal VHF propagation experiments.  Some of our data is posted

Scott Avery, WA6LIE of Salinas, California writes: "I was very
disappointed in last week's ARRL VHF/UHF contest. We got skunked on
6 meters to local only, but worked all the locals on 2 meters on up.

"A few weeks ago I started experimenting with WSPR. Interesting to
see what your station hears, and who hears you. Anyway, most of my
WSPR work has been on 2 meters. Though WSPR is not too popular yet,
I have had some pretty amazing results. Running 20 watts to a 13
element horizontally polarized beam up 40', I usually select Norcal
or Socal to aim.

"Most of the stations are in the SF bay area, but a few new ones
popped up in LA and San Diego area.

"Beaming south, I still hear a few stations 100 miles plus to the
north. To the south N3IZN in Fallbrook is working me at 340 miles
away, and N6KOG at 387 miles several times a day (via tropo?). More
stations and experiments are needed. It would be nice to see more
WSPR stations up on VHF/UHF."

For more info on WSPR, visit and

Rich Zwirko, K1HTV wrote on September 14, about what happened in
September 6: "I got up early and called CQ on CW on 144.330 MHz. An
announce message was made of the DX Cluster. I logged into the
ON4KST.ORG 144/432 website and notified the guys of my
transmissions. A suggestion was made that I transmit on JT65A, which
I started to do on 144.325 MHz. Three EI stations and G4LOH
participated on the European end of the path. Eventually, when I had
to QRT at 1200Z, VE1SKY in NS and K1TEO in CT joined in the test.
But as far as I know, no Trans-Atlantic QSO was made. An additional
attempt may be made early UTC Saturday by stations in W1 and
VE1/9/VO. FYI, G4LOH was the holder of the IARU Region I 2 Meter
distance record 4041 km record for 4 years with a QSO with D44TD.
M0VRL added 75 miles to the record working D44TD in August of 2011.
Some day, with an assist from Hepburn maps, ON4KST chat rooms and DX
Cluster, two Hams will win the Brendan trophies for completing a 2
Meter QSO between Europe and the Americas (North or South)."

Rich included this article from the August 2002 issue of QST:

Dave Clemons, K1VUT of Middleboro, Massachusetts wrote: "In the ARRL
VHF Contest on 6 meters, on September 8, I worked both LU9EHJ and
PY1RO from EMA FN41. I believe these might have been a combination
of TEP and Es since it appears that the QSOs might not have been
equal distance from the equator on both ends.  (Or I could be
geographically challenged!  Either way it was very nice to get that
far south on 6 meters.)"

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 an explanation of the
numbers used in this bulletin, see An archive of past
propagation bulletins is at Find more good
information and tutorials on propagation at

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

Instructions for starting or ending email distribution of ARRL
bulletins are at

Sunspot numbers for September 13 through 19 were 44, 44, 53, 77, 51,
61, and 62, with a mean of 56. 10.7 cm flux was 99.1, 100.5, 97.5,
97.3, 101.5, 104.3, and 109.8, with a mean of 101.4. Estimated
planetary A indices were 6, 5, 6, 7, 6, 8, and 14, with a mean of
7.4. Estimated mid-latitude A indices were 6, 5, 5, 7, 6, 7, and 13,
with a mean of 7.


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