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ARRL Propagation Bulletin ARLP030 (2021)

ARLP030 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 30  ARLP030
From Tad Cook, K7RA
Seattle, WA  July 23, 2021
To all radio amateurs 

ARLP030 Propagation de K7RA

It is exciting to observe increasing sunspot activity.  Recently
solar cycle 25 produced new sunspots frequently, and I watch them
pop up every day on  New sunspots emerged on July
14, 16, 17, 19 and 20, and two new ones appeared on July 21.  When I
look at on July 22, our sun is peppered with
spots, reminding me of past solar cycles.

Average daily sunspot numbers more than doubled from 21.3 last week
to 48.9 during this reporting week, July 15 to 21.  Average daily
solar flux went from 72.9 to 81.3.

Geomagnetic numbers held steady, with both the middle latitude and
planetary A index averages at 6.4.

Predicted solar flux is 89 and 87 on July 23 to 24, 85 on July 25 to
30, 90 on July 31 through August 1, 85 on August 2, 75 on August 3
to 12, then 78, 80 and 80 on August 13 to 15, and 85 on August 16 to
21, and 90 on August 22 to 28.

Predicted planetary A index is 18, 16 and 8 on July 23 to 25, 5 on
July 26 and 27, 8 on July 28, 5 on July 29 through August 1, 8 on
August 2, 5 on August 3 to 9, then 12 and 10 on August 10 and 11, 5
on August 12 to 16, 8 on August 17 and 18, 5 on August 19 to 28, and
8 on August 29.

F. K. Janda, OK1HH sent his geomagnetic activity forecast for the
period July 23 til August 19, 2021, before he takes a week of

"Geomagnetic field will be
Quiet on: July 25, 30, August 7, 12 and 13
Quiet to unsettled on: July 24, 28 and 29, 31, August 9, 14
Quiet to active on: July 23, 26, August 1, 3 to 6, 11, 15 to 17, 19
Unsettled to active: July 27, August 2, 8, 10, 18
Active to disturbed: None predicted.
Parenthesis means lower probability of activity enhancement.

Next Thursday, I will not compile a forecast of the Earth's magnetic
field activity, because I will be walking on the highest mountains
of my country-the Krkonoue Mountains.  Without the conveniences of
civilization as computer or the Internet.  But I will have a good
friends, camera and binoculars with me."

Go to OH6BG on to see his interesting VOACAP links.

I've been having fun using remote SDR receivers at to hunt for 10 meter beacons during the
day.  This revealed much more sporadic-e propagation than I was
previously aware of.

On Thursday, using the AB9MQ receiver in Normal, Illinois via I copied beacons KE5JXC/B in Kaplan,
Louisiana on 28.2515 MHz, WD8INF/B in Lebanon, Ohio on 28.2525 MHz
and KC5SQD/B in Missouri City, Texas on 28.2508 MHz.

You will notice on the beacon
roster that the listings resolve to 100 Hz, instead of 1 KHz.  This
allows more of them to be packed together on the band.  The three
beacons mentioned here today were all copied with the receiver tuned
to the same frequency, and because they transmit on slightly
different frequencies make them easy to copy.

A correction, I mentioned my new CW beacon, K7RA/B on 28.2833 MHz in
last week's bulletin ARLP029.  The power output is actually 11
watts, not 5 watts, I was reminded by UY5DJ/AA7DJ who generously
built the beacon transmitter and controller.

N8II wrote:

"There was much intense sporadic-e, mostly within the USA and Canada
on July 13 to 15 with double hop to MT, UT, WA, OR, BC, CA, NV and

Several times the skip zone shortened to stations less than 300
miles away in NC, SC, KY, and OH.  I easily made over 100 QSOs. I
worked Steve, VE2CSI in Sept-Iles, Quebec, grid FO60 a couple of
times on ten meters and once on six meters, all SSB.

Things were fairly quiet until July 18 when Europe came through well
on 10M starting just after 1200 UTC working 9A2U, Croatia, and Vlada
YU4VLA Serbia, along with Italy, Bulgaria, Switzerland, Belgium,
Scotland, and several German stations until 1319 UTC.

Just after 0000 UTC on the 19th, 10M SSB came alive with stations
from Maine and the US 4th area.  I found TI5KMK in Costa Rica
probably via Es, and also Puerto Rico.  Suddenly on the 21st upstate
NY and New England stations with big signals appeared starting 2214
UTC.  French stations F6ARC and F4AIF were found around 2240 UTC.

Today the 22nd was one of the best openings of the year to western
EU on 10M.  I ran quite a few stations on 28430 KHz SSB after
calling EI2IP and EI3GD in Ireland starting 1941 UTC.  Signal levels
were very good and many stations were active.  The highlight was
being called by Swedish hams SE5S and Hawk, SM5AQD who was peaking
S9 running 1500W to a 3 stack of 8 elements each tri-band Yagis.
Soon after MM0TFU in Scotland called in with a signal a bit better
who I recall uses 400W to a 3 el Yagi.  This was the loudest Ian has
been this year after several 10M QSOs. Around 0040 UTC, I worked
WA2OOO on Long Island, NY less than 300 miles away with a strong
signal as well as VO1VXC, Newfoundland."

From Dr. Tamitha Skov, WX6SWW earlier in the week:

For more information concerning shortwave radio propagation, see and the ARRL Technical Information
Service at  For an
explanation of numbers used in this bulletin, see

An archive of past propagation bulletins is at  More good
information and tutorials on propagation are at

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

Sunspot numbers for July 15 through 21, 2021 were 22, 35, 53, 42,
45, 59, and 86, with a mean of 48.9.  10.7 cm flux was 73.5, 75,
77.4, 80.4, 82.6, 87, and 93.5, with a mean of 81.3.  Estimated
planetary A indices were 10, 4, 4, 4, 7, 10, and 6, with a mean of
6.4. Middle latitude A index was 12, 5, 4, 5, 4, 9, and 6, with a
mean of 6.4.


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