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ARRL Propagation Bulletin ARLP031 (2009)

ARLP031 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 31  ARLP031
From Tad Cook, K7RA
Seattle, WA  July 31, 2009
To all radio amateurs 

ARLP031 Propagation de K7RA

No sunspot activity this week, and if no sunspot appears today, July
31, the average sunspot number for July will be 5.1, down from
June's average of 6.6.

The monthly average of the daily sunspot number, January through
July 2009, is 2.8, 2.5, 0.8, 1.3, 4, 6.6 and 5.1.

The three-month averages for October 2008 through June 2009 were
4.5, 4.4, 3.6, 2.2, 2, 1.5, 2, 4.2 and 5.2.  This takes into account
all the daily sunspot numbers for September 2008 through July 2009,
and those numbers are for the center months of each of those three
month moving average periods.

Last week's bulletin mentioned W5THT and his question about volcanic
ash spewing from Sarychev Peak, and whether this could affect
propagation if it were conductive.  A note from Kaz Siwiak, KE4PT of
Coral Springs, Florida pointed out, ''The ash need not be conductive,
it just needs to have dielectric parameters different from
air/vacuum, which it does.  Yes definitely airborne ash will reflect
radio waves.''  At you can see a photo of
his operating position, and click in the upper right corner of the
page for an image of his simple antenna system.  Beware of his
''Secret Ham Message''.  I clicked on it, and soon found myself trying
to solve the cipher instead of writing the bulletin.

Terry Rogers, WA4BVY of Chapel Hill, North Carolina says he is
really enjoying this solar cycle bottom.  He writes, ''A friend of
mine just got back into ham radio bewailing he picked a poor time
with no sunspots.  Not so.  I got into ham radio in 1958 right when
6 meters was open most days but I have never heard E skip every
other day and all the way to 6 meters multi-hop (I heard N5OMG
comment that night he got a JA7 on 6, and I heard him on 6).  I
don't even have a 6 meter antenna (80/40/20 inverted vees up 20'.
I'm retired in an apartment) but I use the wire I have with good
results out past 1500 miles.  10M E skip comes down just one state
away a lot of times.

I never was able to call CQ on 6 CW before and get several answers.
I worked the first PSK31 ever for me on 6 the other night.  Also, I
came in here yesterday at 5:30 PM EDT about and found the strongest
signal on 40 SSB which turned out to be EA7GAK, Javier, near the
Strait of Gibraltar.  Wow.  Broad daylight 40M DX.  40M is the new
20M.  The path was only half dark.  Not only that, but I come in
here in the evenings and talk SSB with Italy for 15 minutes or so
using 100 watts.  5 watts PSK31 to Italy is easy on 40 with low QRN.
So if this is how 160/80/40 F layer and 10/6 E layer are with no
sunspots, the sun can keep its ole sun spots.''

Terry sent a recording of Javier's booming 40 meter signal, and he
was indeed loud.  On the recording EA7GAK mentioned he is running a
kilowatt and a shortened 4-element monoband 40 meter Yagi one-half
wavelength up the tower, which no doubt helps.

Tomas Hood, NW7US, who writes the monthly Propagation column for CQ
Magazine, now offers a weekly podcast devoted to radio propagation.
Go to to listen.  He has produced two so
far, for July 18 and 25, so the next one should be on Saturday,
August 1.

World Radio magazine ceased publishing a hard copy of their monthly
journal, but they are still publishing by posting PDF documents on
the web.  Best of all, Carl Luetzelschwab, K9LA still writes his
monthly propagation column for them.

Go to and click on
Back Issues in the left column.  You can download the entire content
of all 2009 issues by right-clicking on the link below each month,
then saving to your drive.  Carl's column is always in the higher
numbered pages, so if you want to get to his column quickly, just
download the last section only.  Carl is very knowledgeable about
propagation, and his articles are always interesting and
informative.  Also check out Carl's website at to read more of his writing.

Seems that great sporadic-E propagation continues.  Mike Schaffer,
KA3JAW in Tampa, Florida was searching for television DX last
Saturday, July 25, when he received HIJB in the Dominican Republic
on channel 2 with fair video quality and moderate audio during the
1230z hour.  At 1330z he received TGV on channel 3 from Guatemala,
and at 1400z on channel 4 he received a station in Managua,
Nicaragua.  He notes that the previous weekend had poorer sporadic-E

Several days earlier, Wednesday, July 22 around 11:00 PM Central
Time (0400z Thursday) Trent Fleming, N4DTF of Germantown, Tennessee
(EM55) worked 14 stations in Northern Illinois, Minnesota and
Wisconsin on 6 meters.  The grid squares were EN52, EN53, EN25, EN34
and EN62, and all signals were at least S7.  First QSO was with
KK9H, then a pileup ensued, and the last worked was KN0V.  After
signing with KN0V, the band dropped out completely.

Trent runs 50 watts into a horizontal loop at 25 feet.

Dale Drake, AA1QD of Dover, New Hampshire (FN43mf) noted in last
week's bulletin the story about working JA7QVI on six meters, and
said they worked each other on 6 meter CW on July 8 at 2304z.  Dale
said it was quite a thrill, and noted that JA7QVI is running stacked
Yagis on six, eight over eight.  Dale says, ''Overall the 6M E skip
season here started out a bit slower and later than usual in May but
it really picked up in June and July.  I ended up working 12 new
countries for me on 6 so far this season.  Im now up to 86 worked in
my quest for 6M DXCC.

Victor Androsov, VA2WDQ worked quite a bit of sporadic-E on 2 meters
on Wednesday, July 29.  He uses a 7 element Yagi that he designed,
and it is on a 2 wavelength boom.  He wrote, ''That was the biggest
2m Es I've ever heard since I've licensed as VA2WDQ in 2003.  I
found 144 MHz opened to W0 at around 18 EST (22 UTC).  The first
station I've worked at 18:13 EST was N0IRS from EM29 coming with
strong and clear signal.  The last one QSO with WR0F (EM29) logged
at 19:48.  Anyway I heard other stations I've worked before until
20:00.  That was a great opening.  Sometimes MUF dropped down and
the 2m band got quiet.  But after 10-15 minutes W0, W9, W5 jumped up
from noise again''.

''That Es opening I worked 17 stations:  N0IRS, KC0CFB, WB0NQD, W9RM,
KM0T, K5OMC, and WR0F in these grid squares: EM25, EM26,
EM27,EM29,EM39, EM44, EM55, EN10, EN13, EN22, EN40, EN41, and EN52''.

Larry Lambert, N0LL of Smith Center, Kansas had his own adventure on
2 meters on the same evening.  He wrote, ''With all the sporadic E
this summer this happen last evening July 29th at 2343z.  K1WHS in
Maine was worked on 2m for state number 48 on 2m.  All states were
non EME and non digital.  My state number 47 was W1AIM in Vt. during
the 1998 Leonids meteor shower, so number 48 has been 11 years in
the coming.  I've been on 2m weak signal for 33 years.  W9GKA,
Kevin, says I am number 13 to do all contiguous 48 states on 2
meters.  One has to live in the Midwest to do it.  My 2m signal was
heard in Maine in July 17th 1980 and that is as close as it got till
last evening.  Long time to wait for another cloud to be in the
correct location as this was near the theoretical 1500 mile limit
for one hop of sporadic E on 2m.  Also worked 7 others in New
England.  Was quite a thrill''.

For this weekend, the planetary A index is predicted at 7, which is
slightly more active than it has been lately.  A solar wind from a
coronal hole would be the cause.  We are hoping for a return of a
recent sunspot group, but only a weak sunspot was spotted from
European observatories this morning.

Geophysical Institute Prague predicts unsettled conditions July 31,
quiet to unsettled August 1, quiet August 2-4, quiet to unsettled
August 5, and unsettled August 6.

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 23 through 29 were 0, 0, 0, 0, 0, 0, and 0
with a mean of 0.  10.7 cm flux was 67.8, 68.3, 69.1, 67.6, 68.4,
68.7, and 68.3 with a mean of 68.3.  Estimated planetary A indices
were 8, 6, 7, 3, 4, 4 and 2 with a mean of 4.9.  Estimated
mid-latitude A indices were 8, 5, 5, 1, 2, 3 and 2 with a mean of


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