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ARRL Propagation Bulletin ARLP045 (2011)

ARLP045 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 45  ARLP045
From Tad Cook, K7RA
Seattle, WA  November 11, 2011
To all radio amateurs 

ARLP045 Propagation de K7RA

Another sunspot number record for Cycle 24 was shattered on
Wednesday, November 9 when the daily sunspot number reached 220.
This is the highest the daily sunspot number has been in over eight
years. The last time the sunspot number was higher than 220 was
November 1, 2003 when the number was 277. The next day (November 10)
the daily sunspot number dropped back to 164.

Two days prior to the sunspot number reaching 277 in 2003, the
sunspot number was 330, a much harder record to beat.

Average daily sunspot numbers this week rose over 53 points compared
to last week, to 153.4. Average daily solar flux rose nearly 39
points to 173.7.

The latest prediction from NOAA/USAF has solar flux at 180 on
November 11-12, 175 on November 13-14, 170 on November 15-17, and
160, 155, 145, 140, 135, 135 and 140 on November 18-24, and 145 on
November 25-28.

Planetary A index is predicted at 10, 20 and 15 on November 11-13,
then 5 on November 14-25, and 7 on November 26-27.

The A index of 20 predicted for November 12 seems to reflect a
warning from IPS Radio and Space Services (in Australia) at 2330 UTC
on November 9. It announced expected increased geomagnetic activity
November 10-12, with quiet conditions November 10, unsettled to
active with isolated minor storm levels on November 11, and quiet to
unsettled with isolated active levels on November 12.

Geophysical Institute Prague says look for quiet to unsettled
conditions November 11, unsettled to active November 12, quiet to
unsettled again on November 13, and quiet November 14-17.

Much attention has been focused over the past few days on sunspot
group 1339, which is now rotating through the region that has
maximum effect on Earth, right around the center of the visible
solar disk. National Geographic has an article about this at

If you like solar reports with dramatic music, check out a video on
1339 at, and note that
you can select a higher resolution and larger screen image. Pay no
attention to much of the material that appears after this video
about the Mayan calendar, mysterious invisible planets, UFOs,
end-of-the world asteroids, etc.

Sky and Telescope also features a piece on 1339 at
Check out the gallery of photos at

Sebastian Costa, W4AS of Cutler Bay (Miami area), Florida wrote
about an interesting experience this week with very low power.

He writes, "On Tuesday November 9, 2011 at 0121 UTC, I was listening
on 20 meters SSB. On my panoramic adapter, I saw a very strong
signal. It was Jerry, P40GH in Aruba.

"His signal was often 30-40 dB over S9 on my Elecraft K3 and Force
12 C-3SS tri-bander. I decided to give him a call barefoot, and
after a couple of tries, he came back to me, and we had a short QSO
as he was running quite a pileup.

"I kept the rig on his frequency, and a few minutes later he asked
if there were any QRP or mobile stations, I quickly brought the
power down to 5 watts and called him. He said I was still S9+, and
that he would listen as I dropped my power. With 2 watts output, he
said I was about S7. Down to 1 watt I was still S7.

"So I thought, well what happens with 500 milliwatts?  At that
'power' I received an S5 report. Finally, I went down to 100
milliwatts, and at that 'power' he said I could still be copied!

"It reminds me of years ago as a kid, I received a CB walkie-talkie
for Christmas one year, and with the 100 milliwatts it had, I was
excited to talk to my neighbor across the street. And now with the
great conditions we have, that same amount of power (albeit with a
much better antenna), can work well over 1,000 miles."

Scott Woelm, WX0V of Fridley, Minnesota writes, "When Bill, ND0B
asked me for a 17m CW sked request (via the K3UK Sked Page), on
10/25/11, I laughed. Bill is in ND, I am in MN. Fat chance. I was
wrong; Bill was solid! We had a nice aurora opening. Needing ND on
multiple bands via QRP, Bill got me 20m, 17m, 15m, 12m, and 10m.
This was from 0121z through 0207z. That was fun!"

Scott mentioned the K3UK sked page, which you can find at

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 November 3 through 9 were 161, 100, 135, 144,
154, 160, and 220, with a mean of 153.4. 10.7 cm flux was 160.4,
163.9, 171.9, 176.7, 182.1, 181, and 180.2, with a mean of 173.7.
Estimated planetary A indices were 3, 4, 4, 3, 4, 6, and 2, with a
mean of 3.7. Estimated mid-latitude A indices were 3, 3, 3, 3, 4, 6,
and 2 with a mean of 3.4.


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