Register Account

Login Help

ARRL Propagation Bulletin ARLP029 (2008)

ARLP029 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 29  ARLP029
From Tad Cook, K7RA
Seattle, WA  July 11, 2008
To all radio amateurs 

ARLP029 Propagation de K7RA

Another week, and still no sunspots.  The three month moving average
for daily sunspot numbers that we began reporting toward the end of
cycle 23 seemed to suggest retrospectively that solar minimum
occurred last fall.  The daily average for the three month period
centered on last October was nearly 3, or 2.967 to split some hairs.
This is an average of the 91 daily sunspot numbers from September 1
through November 30.

Following that low, November was 6.85, and between December 2007
through April 2008 the 3-month average drifted from 8.14 to 8.89.
With remaining cycle 23 spots becoming increasingly rare, and barely
any cycle 24 spots, this suggested solar activity was stalling out.

Then at the end of June, a further decline, when the 3-month average
centered on May dropped to 5.04.

Randy Crews, W7TJ of Spokane, Washington has an interesting
observation regarding a possible double-minimum between cycles.  He
was looking at some charts of past sunspot cycles in W3ZZ's World
Above 50 MHz column on page 90-91 in the February 2008 issue of QST.
Randy wrote, ''I noted the average period from a cycle's peak
declining to its low is on average 7 years.  So, linking that to our
current cycle's progress, things get interesting:  If you count from
the 1st cycle 23 peak (April or July of 2000) we are at the 8 year
mark now and past due.  However, cycle 23 had a second peak
November/December of 2001.  We have not yet reached the 7 year mark
if you count from peak #2 and that would coincide perfectly with
Ken's article.  Interesting enough, the NOAA propagation charts
predict this fall as being the real pickup''.

When Randy mentions ''Ken's article'', he is referring to Dr. Kenneth
Tapping of the Dominion Radio Astrophysical Observatory in
Penticton, British Columbia, the source of our daily 10.7 cm solar
flux numbers.  Following a widely circulated false quote attributed
to Tapping, we made available his notes on the cycle minimum to
anyone who sends a blank email to  That offer
still stands, and to date over 1,100 copies have been dispatched to
readers who sent an email to that address.

Randy also mentions ''NOAA propagation charts'', but I suspect he
means tables of predicted smoothed sunspot numbers.  Those can be
found at and on
page 8 at

So what do zero sunspots mean for HF propagation in mid-July?  From
my home in Seattle, the path to Japan has a Maximum Usable Frequency
that varies from a low of 13.1 MHz at 1630z to a maximum of 16.8 MHz
at 0530z.  To Hawaii, the lowest MUF is 11.3 MHz at 1200z to highest
of 17.2 MHz at 0500z.  A further example is Texas to Brazil, with
MUF ranging from 6.4 MHz at 0900z to 20.8 MHz at 0200z.  That is all
a very narrow range.  With an average sunspot number of 100 for that
Texas to Brazil path, low of 18.2 MHz at 0900z to 29.7 MHz at 1730z
and 2100z, enough to support good 10 meter propagation.

Sporadic-e propagation on 10 and 6 meters generated more mail this

Jeff Hartley, N8II of Shepherdstown, West Virginia sent the
following report on July 4.

''Just a quick note to mention the 6M condx on June 27-28.  Around
2000Z on the 27th the Es opening began on 50 MHz here.

''I had very bad luck getting any Europeans to answer my CQ and my
Euro footprint was pretty small to northern F, PA, southern G, and
EI.  I worked a total of about 6 stations in the mentioned
countries.  There were a few weak signals persisting past 2200Z
(heard MM0AMW).

''Most all of the activity was on CW, long live CW!

''Saturday morning, June 28, I turned on the radio to find loud
Italians all over the 50.080-50.100 segment at 1320Z.  I worked
quite a few in the I-4 call areas.  There was a loud IZ1 who
couldn't hear 3/4 of the stations calling him and I heard a weak I7.

''I worked a total of about 15 stations over 45 minutes or so and
again there was surprisingly much more activity on CW than phone.
This time, I did get a few CQs answered.  Also heard were S57RR,
9A1CCY, and a 9A6, but the pile-ups were big and unruly on the first
2 guys.  K1HTV near DC missed the S5 due to two callers out of turn.
I would have persisted, and not let the ''breakers'' in if I were the

Joaquin Montoya, EA2CCG says on June 30 there was a nice 10 meter
opening to the Caribbean with Martinique booming in, and Ecuador
also.  July 2 had him working his first 6 meter sporadic E skip,
with a dozen European stations out to about 1500km.  They were all
from Poland, Denmark and Germany.

Russ Hunt, WQ3X on Kitner Hill in Upper Black Eddy, Pennsylvania
mentioned on July 6 that there were great 6 and 10 meter openings on
June 27-28.

He wrote:

''On 6-27 I worked the following stations on 10M SSB: 
2337 LA0EM 
2340 4O3A (59+) 
2343 EA1ALE 
2348 MW0JZE 
2350 MM0SJH (59+)

''Many of these stations said they had to go to bed but didn't want
to!  The band remained open the following morning and most of the

''On 6-28 I worked two stations on 10M CW: 
2152 EA7UU 
2156 IT9EJW (called me after I finished with EA7UU and we went up 1
for a short exchange)

''It was amazing and really lifted my spirits!!  I was running an
FT-1000MP with Collins 30S-1 amp at about 1KW output into a 5
element monobander (105-BA) at 50 feet.  My elevation here on
Kintner Hill is about 600 feet.''

Russ heard about the 6 meter reports on a spotting network.

Jon Jones, N0JK had a July 4 report from Kansas:

''I worked TO5E (St Barts) 6 meter DXpedition on July 4!!  I was
operating portable in the Flint Hills of eastern Kansas from a
hilltop with a 2 el Yagi and 100 watts.

''I first heard TO5E on 50.108 around 1350 UTC.  Weak residual almost
like scatter.  He gradually built up and I heard them work K0RU EM28
on CW.  Then I got through.  Some QSB and I worried TO5E would drop
out before finishing the QSO!  But got my 559 fine and they

''TO5E continued to build and at 1410 UTC was solid on SSB.  By 1425
UTC TO5E peaked well over S-9!  Oddly TO5E had few callers, CQ'd
many times.  I also worked KP4SQ and Julio, NP3CW at 1430 UTC.

''KP4SQ had a bigger pileup on him than TO5E did.  Go figure!

''I called Larry, N0LL and my wife N0HKT on my cell phone and let
them hear TO5E.

''This was the first decent Carib. Es opening I have caught this
year.  The opening acted more like F2 than Es in that I heard no
stateside signals at first.  Only the Carib.  DX.  Later the K4MHZ/b
FM25 appeared.

''TO5E has had some other good openings to the USA including July 1
when they worked all the way to VE7.''

Greg Andracke, W2BEE of Pine Plains, New York wrote:

''After about 52 years as a CW operator on the lower HF bands, the
mention yet again in your bulletin of the activity on 6 meters
prompted me to get the radio out of the closet and hook it to an HF
ground-mounted vertical to see what would happen on 6.

''With a match in the 2:1 range and about 100w out, I worked N5GW,
W5DNT and K5FA in short order on 7 July 08 from FN31ew at about
0045Z.  Enough fun to get me to eventually put a Yagi on this band!

Scott Avery, WA6LIE of Salinas, California seemed to be very excited
when he wrote to us on July 7.  Why?  More six meter propagation, of

Scott is in grid square CM96, and on July 7 he said 6 meters was
''HOT!'', from 2300-0500z.  He was working East Coast stations from
Pennsylvania to Florida, ''and everywhere in between''.

He worked many CN85-87 (Western Oregon and Washington), and had many
pileups from CN85 (Portland, Oregon).  For 6 hours, after swinging
the beam to the east, he worked many upper Midwest and New England
stations in EN and FN.

He didn't hear Japan, but he noticed Chip, K7JA working Japan around
0000z on 6 meters CW.

While writing the email, he said he was working K5HCT in Odessa,
Texas at 0535z.

At 0610z he wrote to say six meters was still open, and he was
having a long QSO with KJ6AP in Vancouver, Washington, but it was
time to go to bed.

WA6LIE has set up his station to be operated remotely by others.
Details are on

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 at  For a detailed
explanation of the numbers used in this bulletin, see  An archive of past
propagation bulletins is at  Monthly
propagation charts between four USA regions and twelve overseas
locations are at  Instructions
for starting or ending email distribution of this bulletin are at

Sunspot numbers for July 3 through 9 were 0, 0, 0, 0, 0, 0, and 0
with a mean of 0.  10.7 cm flux was 65.5, 65.4, 65.1, 66.1, 65.5,
65.5, and 66 with a mean of 65.6.  Estimated planetary A indices
were 4, 4, 7, 4, 3, 2 and 4 with a mean of 7.  Estimated
mid-latitude A indices were 3, 3, 7, 5, 2, 1 and 3 with a mean of


Instragram     Facebook     Twitter     YouTube     LinkedIn