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ARRL Propagation Bulletin ARLP035 (2020)

ARLP035 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 35  ARLP035
From Tad Cook, K7RA
Seattle, WA  August 28, 2020
To all radio amateurs 

ARLP035 Propagation de K7RA

Our closest star seems to have quieted again.  We have now
experienced seven consecutive days with no sunspots at all.

Average daily sunspot number dropped from 5.4 to 1.9 this week, and
average daily solar flux declined from 71 to 70.4.  Geomagnetic
indicators increased marginally, with average daily planetary A
index going from 4.4 to 5.1, and average middle latitude A index
from 5 to 6.

Predicted solar flux is 70 on August 28 to September 3, 71 on
September 4, 72 on September 5 to 9, 71 on September 10 to 16, 70 on
September 17 to 27, 71 on September 28 to 30, 72 on October 1 to 6,
and 71 on October 7 to 11.

Predicted planetary A index is 8, 10, 12 and 8 on August 28 to 31, 5
on September 1 to 17, 8 on September 18 and 19, then 10, 15 and 10
on September 20 to 22, then 5, 10, 12 and 18 on September 23 to 26,
15 on September 27 and 28, 12 on September 29, and 5 on September 30
to October 11.

OK1HH is on his annual hiatus, so no geomagnetic prediction from him
this week.  Instead, we present a much more limited forecast from
Tomas Bayer of the Budkov Observatory.

"Geomagnetic activity forecast for the period August 28 to September
03, 2020

Quiet:  August 27, September 1 to 3
Unsettled:  August 27 to 31, September 1 and 2
Active:  Possibly on August 30 and 31
Minor storm:  0
xhMajor storm:  0
Severe storm:  0

Geomagnetic activity summary:  
Friday, August 28, we expect at most quiet conditions.  On the same
day, in the evening, more unsettled conditions are possible.

The most unsettled conditions are expected during the coming
weekend, August 29 and 30.  The unsettled stage can also peak by any
isolated active event.

From Monday, August 31, we expect waning of the unsettled conditions
to the quiet to unsettled level.  The first three days of September,
we expect quiet conditions to return."

Now, since sunspots are fading (I assure you this is temporary) we
have received another of the occasional reports from Cycle 19.

"I love reading your weekly prop report hoping to see the beginning
in the new cycle.  So far, not much news, so I reminisce about that
fantastic cycle 19.  Not many active hams have lived through the
cycle, but I did.  I would love for everyone to experience another
cycle 19 in the next 10 years.

I received my novice license in 1954 at the age of 16.  My station
was an S38 and a homemade 6V6 xmtr on 80 meters, crystal controlled.
Later I was given a 40 meter crystal and I enjoyed more distant
QSOs.  One night I was called by a very strange call and I learned
that I was talking to CM7JA in Camaguey, Cuba.  My first DX and I
was hooked.  I built a mighty Heathkit AT1 and moved to 15 meters in
my quest for DX.  Hawaii was my 1st DX on 15.  Novices were allowed
on 80, 40, and 15 at that time, crystal controlled only.

I received my General class license in 1955, built a Heathkit VFO.
Now I was set for DX.  In late 1954 the SSN was bouncing around 5,
good for 80 and 40.  In late 1955 the SSN was bouncing around 70 and
20, 15, and 10  were alive with signals from everywhere.  I was in
hog heaven!  I upgraded to an NC-98 receiver and a Globe scout
transmitter and in late 1956 the SSN was about 160, I thought DX
could not be better than this.
But it did!  I built a homemade 10 meter beam made from bamboo poles
wrapped in aluminum foil and could contact anyone I could hear.  By
the end of 1957 the SSN was 200 with excursions to 250.  All the
high bands (20, 15, and 10) were open all night long!  Ten watts and
a wet string could work the world.  It was fantastic!  Most of my
operation was on CW with an occasional QSO on AM if I heard a new

By 1958 school and girls competed with radio for my attention, but I
always found some time to operate.  SSN was still up around 160.
Soon it was graduation, job, marriage, and kids but I always found
time to flip the new and improved rig on.  I was also working on
getting those elusive QSL cards to improve my DXCC standing.

Now at 82 yo I am still working DX but mostly on FT8 and I am
looking forward to an exciting cycle 25.  I hope y'all can
experience what I did."

Thanks, Bill for the report from the middle of the 20th century!
Nice to hear of a Yagi built from bamboo poles wrapped in aluminum

I hope we see more sunspots soon, and one thing we have to look
forward to currently is improved propagation due to seasonal
effects.  We are just a few weeks away from the autumnal equinox.

A new video from WX6SWW, Dr. Tamitha Skov, the Space Weather Woman:

For more information concerning 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 August 20 to 26, 2020 were 13, 0, 0, 0, 0, 0,
and 0, with a mean of 1.9.  10.7 cm flux was 69.9, 70.9, 70, 70.6,
70.3, 70.6, and 70.4, with a mean of 70.4.  Estimated planetary A
indices were 3, 4, 8, 7, 3, 4, and 7, with a mean of 5.1.  Middle
latitude A index was 4, 5, 13, 7, 3, 3, and 7, with a mean of 6.


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