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ARRL Propagation Bulletin ARLP032 (2009)

ARLP032 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 32  ARLP032
From Tad Cook, K7RA
Seattle, WA  August 7, 2009
To all radio amateurs 

ARLP032 Propagation de K7RA

We had some nice sunspot activity from July 3-10, and were hoping
for a return 27-28 days later, but it never happened.  Varying by
latitude, the sun rotates relative to earth about every 27.5 days.
If that same region was still active or activity renewed, then we
might have seen something between July 30 and August 7, which is
today.  Instead, the quiet continues.

Some rather odd numbers appeared on August 5.  Check out the eight
planetary K index readings on that date at and note that they
never varied.

Dean Lewis, W9WGV of Palatine, Illinois wrote this week asking about
the most likely path that his signal took on July 12.  Because of
local restrictions, he uses inside wire for an antenna, so he can't
tell for sure which direction a signal is coming from.  At 0620z in
the IARU HF World Championship he worked VK2AYD on 20 meter CW.  He
wondered if the path was most likely over the Pacific, or the
Atlantic Ocean and Africa?

I ran some numbers on W6ELprop (download from and used a location of 42.148 deg N
and 88.014 deg W for Dean, and according to the entry on,
VK2AYD is in grid square QF68in, which W6ELprop translates to 31.44
deg S, 152.71 deg E.  W6ELprop indicates that the short path is
9,069 miles with a beam heading from Illinois of 262 degrees.  Long
path is at 82 degrees from Dean, at 15,806 miles.

With a smoothed sunspot number of 3, it shows that they worked each
other at the optimum time for that band.  From 0400-0600z the
program predicts signals at 19, 21, 23, 24 and 25 db above .5
microvolt, on half hour intervals.  After that, signals drop out,
which is exactly what Dean experienced.

Any possible long path opening would be much weaker and also
earlier, according to the software.  It says 2300-0000z is most

Among six meter reports this week, Bill Turner, W4WNT says he was
mobile running 40 watts on the beach at Oak Island, North Carolina
(FM03) when he worked EA8CQS (IL18) in the Canary Islands on phone
on July 29.  Bill was using one of those popular and inexpensive
monoband whips on the back of his car.

Jon Jones, N0JK of Wichita, Kansas had a lot of 2 meter e-skip
excitement on July 29-30, but missed openings the following day.
One July 29 he worked (with UTC, call, grid square and state
abbreviation) 2242 W1AIM FN34 VT, 2245 K1WHS FN43 ME (heard off and
on for over an hour.) 2,300 km, 2252 W2RJO FN23 NY, 2332 KC2RDC FN14
NY, 2349 VE2DFO FN25 QC.  He sent a link showing the K1WHS station,
at  Jon was using a 7
element Yagi on a stepladder in his bedroom.  It was facing
northeast, but Jon didn't say if the antenna was pointed out the

George Ackinclose, W4GNE of Chesterfield, Virginia had an exciting
time with that same sporadic-e 2 meter opening on July 29 from
2200-0000z.  He was using a 12 element Yagi on a 20-foot boom, but
just 25 feet above ground.  George reports that he worked ''K0AWU in
EN37, Minnesota (approx 1,000 mi.), K0SIX in EN35, Minnesota, KA9CFD
in EN40, Illinois, WB0ULX in EN04 South Dakota (approx 1,200
miles.), K0KFC in EN35, Wisconsin, K0CJ in EN34, Minnesota and N0UK
in EN34, Minnesota''.

''I have only been in amateur radio since Dec. 2002 and that was the
most heart racing, adrenaline pumping action on ANY band that I have
been a part of... so far.  I'm certain that if I had a little better
antenna height I would have worked a lot more, I heard many others
just too far down in the noise for me to pick out''.  All these
contacts had good signals, S5-S9.

Roger Harrison, VK2ZRH sent an interesting email concerning a
3-month running mean of sunspot numbers he has been looking at.  You
can see his analysis and discussion at  Roger
wrote, ''During the late-1980s, I worked with Dr Leo McNamara to
produce a series of 9 articles titled ''Radio Communicators' Guide
to the Ionosphere'', published in Australian Electronics Monthly (I
was Editor/Publisher), Dr McNamara subsequently developed that into
a book - ''Radio Amateurs Guide to the Ionosphere'', published by
Kreiger.  More recently, from around 2002, I began re-acquainting
myself with the world of sporadic E research and sporadic E VHF

This weekend is the Worked All Europe DX CW Contest.  Conditions
should continue to be quiet, although currently on Friday morning
the interplanetary magnetic field is pointing south, leaving our
earth vulnerable to a solar wind stream.  Predicted planetary A
index for August 7-11 is 5, 5, 7, 5 and 5.

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 30 through August 5 were 0, 0, 0, 0, 0, 0,
and 0 with a mean of 0.  10.7 cm flux was 68, 68.7, 68.1, 68.1,
67.4, 65.8, and 66.2 with a mean of 67.5.  Estimated planetary A
indices were 3, 5, 4, 3, 10, 4 and 6 with a mean of 5.  Estimated
mid-latitude A indices were 2, 4, 3, 2, 7, 4 and 5 with a mean of


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