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ARRL Propagation Bulletin ARLP024 (2021)

ARLP024 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 24  ARLP024
From Tad Cook, K7RA
Seattle, WA  June 11, 2021
To all radio amateurs 

ARLP024 Propagation de K7RA

Sunspot activity has given us steady but modest increases over the
past three weeks, with average daily sunspot weekly averages rising
from 24.9 to 28 last week to 34.9 this week.

But oddly, average daily solar flux for the same three weeks was
77.8, then 77.8 again last week, and now 77.7 over the latest seven
day reporting period, remarkably unchanged week after week.

Average daily planetary A index went from 6.1 last week to 5.9 in
this week's report, and middle latitude A index was 6.3 and then

Predicted solar flux over the next month is 75 on June 11-20, 80 on
June 13-17, 75 then 80, 82 and 77 on June 21-23, 76 on June 24 to
July 5, then 74, 74 and 75 on July 6-8, 74 on July 9-14 and 75 on
June 16-17.

Predicted planetary A index is 5 on June 11-13, 8 on June 14-15,
then 20 and 18 on June 16-17, 5 on June 18-25, 7 on June 26, 5 on
June 27 through July 4, then 15, 10 and 8 on July 5-7, 5 on July
8-12, 20 and 8 on July 13-14, and 5 after mid-July.

Geomagnetic activity forecast for the period June 11 til July 7,
2021 from F.K. Janda, OK1HH who has compiled these reports weekly
beginning in January, 1978.

"Geomagnetic field will be:
quiet on: June 12-13, 18-20, 24, 27-28, July 1-2
quiet to unsettled on: June 11, 15, 17, 29-30, July 6
quiet to active on: June 11, 14, 17, 21, 25-26, July 3-4
unsettled to active: June 16, 22-23, July 5
active to disturbed: - none
"Solar wind will intensify on: June (11-13,) 17 (-18,) (22-24, 29,)
July (2,) 4-5.
"Parenthesis means lower probability of activity enhancement."

Checking the STEREO mission at every
day we see more activity in store over the Sun's eastern horizon.
You will recognize it as intense white splotches

Watching 6 meters on on Wednesday night at 10:50 PM
PDT (0550 UTC Thursday) I noticed an odd late night opening in
western North America. Showing many long distance FT8 contacts, some
had positive signal reports, above the noise. This is notable
because most reports on this web site show negative signal strengths
of -17 to -20 dB, but one stood out. It was a 609 mile +5 dB signal
report from K6VVP in San Francisco (CM87rs) to WA7DUH in Eastern
Washington state (DN06hg). Later I saw a 727 mile report from KA9UVY
(EM58mk in Illinois) to N3OUC (FN20fm in Pennsylvania) at 0632 UTC
but the signal report at only -10 dB. Both reports showed the
frequency as 50.314 MHz.

Of course, when FT8 signal reports are above 0, the same path should
be viable for other modes, such as CW and SSB.

Michael May, WA8VLC/7 in Salem, Oregon wrote:

"It's been 2 weeks since an update and aside from some FT8, SSB and
CW DX and stateside on 6 meters, including Trinidad and Hawaii on
50.313 and some Midwest and eastern US and Canada on 6 meter FT8,
SSB and CW mostly last week, still the most interesting and weird
things still occurred on 10 meters both ham and non ham activity.
"On May 31 on 29.62 MHz FM I found the KQ2H repeater in New York in
for several hours and I spent most of the day talking to several
hams all over the Eastern and Southeast US on this repeater which
never faded for the entire day.
"I actually took an hour break and went to 10 SSB and worked French
Guiana on 10 SSB and when I came back the 29.62 repeater was still
20 dB over S9, this was simply the best 10 meter activity I have
seen in years on FM.

"10 meter weirdness again non-ham stuff:

"Last nite on June 9th UTC time at 0330 to 0355, me and another
Salem ham, K6FIB, both heard on 3 different radios at 2 different
locations and different antennas several non-ham french speaking
stations coming thru my 10 meter remote base on 29.6 FM speaking to
another much weaker non-ham for 15 minutes.

"At this time I zeroed my 4 el 10 meter Yagi to a ~195 degree
heading which put them somewhere in the Eastern Pacific, but where?
"After some searching around on other 10 meter frequencies I heard
similar voices on 28.700 FM speaking a similar French dialect but
this time there were two of them readable and one that appeared to
be a base station who was much stronger and another one he was
chatting with that was much weaker but still readable.
"After listening to the 28.700 FM transmission for half an hour the
strong one identified saying 'Pape'ete radio' at 0355 UTC and
several minutes later they slowly faded out.
"This would put these transmissions in Pape'ete in French Polynesia
but most interesting is that again there were no FM hams on in that
region on 10 meters.

"In the past 30 years I have never heard a ham station from these
locations on FM so not surprising at all; however, there were South
Pacific hams in ZL on 28.074 FT8 and 10 meter CW at the same time.
"These stations, aside from French speaking, sounded like a standard
FM Land Mobile agency that one would hear on VHF. But I am now
discovering more of these weird non-ham signals between 26 and 39
MHz from non US locations."

[Great investigative work, Michael! Readers may recall in ARLP022
Michael reported hearing North Korean squid fishermen on 10-meter
FM. Quite the catch. -K7RA]
"My recent logs, times in UTC:
"2021-06-06    2011 KC7I/KH6       50.313    FT8  BL10
2021-06-06     1950 9Y4D           50.313    FT8  FK90gg                    
2021-06-03     0359 K7EME          50.155    SSB  DM42jh               
2021-06-03     0358 K7ZYP          50.155    SSB  DM41KX               
2021-06-03     0232 W7PMS          52.560    FM   DM34tn Prescott, AZ       
2021-06-01     0207 WB7PMP         50.145    SSB  EM95pu               
2021-06-01     0205 K9PPY          50.125    SSB  EN51xx               
2021-06-01     0128 WS9V           50.092    CW   EM59DL          
2021-06-01     0118 W3HKK          50.099    CW   EN80qe               
2021-06-01     0108 K9PPY          50.095    CW   EN51xx               
2021-06-01     0103 K9MRI          50.099    CW   EN70iu
               1708 WA8FGV         50.125    SSB  EN82ig               
               1705 K1EAR          50.125    SSB  DN84lc               
2021-05-31     0110 VE2XK          50.313    FT8  FN07pj               
2021-05-31     0100 VE4VT          50.313    FT8  EN19kt                    

"10 meters on the KQ2H FM repeater, 29.62 in NY state and French
Guiana on 10 SSB.

"2021-05-31    1952 KR1COP         29.620    FM   FN21tr
2021-05-31     1952 W2GGI          29.620    FM   EL96wk               
2021-05-31     1949 KD2VQR         29.620    FM   FN21ro               
2021-05-31     1945 KD2SBO         29.620    FM   FN21TO               
2021-05-31     1933 KK4ANE         29.620    FM   EL97RV               
2021-05-31     1932 AA2EC     10m  29.620    FM   FN32dg
2021-05-31     1915 FY5HB     10m  28.441    SSB  GJ34WH"

Jon Jones, N0JK reported from Kansas EM28 on Saturday, June 5:

"Saw the East Coast had a big Es opening to Europe all afternoon
June 4. Nil out here.

"May 30 and 31 good here. On May 31 had JA8JEP (QN03) in at -14 dB
2238z 50.323 MHz FT8.

"Today (June 5) XE2X spotted 9K2OD on 50.323 MHz FT8 at 1335z. That
is remarkable.

"2021-06-05 13:35 XE2X (EL06VC) 50.323.0 FT8 
9K2OD (LL49AI) 12,871 km Multihop Sp-E  FT8 -06 TNX LOUD"

Check for a video of the huge antenna array
built for the former Soviet over the horizon HF radar, the Russian
Woodpecker, a constant annoyance for HF operators a few decades ago.
Quite impressive, though!

The web site for the Apache Point Observatory in Sunspot, New
Mexico, is:

The latest video from Dr. Tamitha Skov, WX6SWW, can be found at:

If you would like to make a comment or have a tip for our readers,
please email the author at, .

For more information concerning shortwave radio propagation, see and the ARRL Technical Information
Service web page 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 June 3 through 9, 2021 were 28, 30, 30, 42, 53,
34, and 27, with a mean of 34.9. 10.7 cm flux was 75.5, 77.1, 74.4,
77.4, 80.8, 79.9, and 78.6, with a mean of 77.7. Estimated planetary
A indices were 6, 5, 4, 5, 12, 5, and 4, with a mean of 5.9. Middle
latitude A index was 8, 4, 4, 6, 15, 7, and 4, with a mean of 6.9.


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