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ARRL Propagation Bulletin ARLP035 (2008)

ARLP035 Propagation de K7RA

QST de W1AW  
Propagation Forecast Bulletin 35  ARLP035
From Tad Cook, K7RA
Seattle, WA  August 22, 2008
To all radio amateurs 

ARLP035 Propagation de K7RA

Another week of quiet sun, but on Wednesday and Thursday, August
20-21, a new spot seems to be emerging.  There is no sign that it is
anything other than an old cycle 23 spot. reported
it with a sunspot number of 11 for August 21, but NOAA did not,
reporting zero instead for Thursday.  A late Thursday image at suggests a spot in the northern hemisphere
on the left side of the image.

About a year and a half ago in bulletin ARLP010 we speculated
whether solar cycle minimum had been reached.  The same issue
mentioned a personal quest by JQ2UOZ to work DXCC at the solar cycle
minimum running only one-half watt on 17 meters and higher using
dipole antennas.  In an email this week he said he has reached his
goal.  So far he has worked 138 countries, and you can see details
on his web site at

Tony Dixon, G4CJC produces a weekly report on the ten meter band,
including calls heard, at  Even at the bottom of
the cycle, there is still propagation on 10 meters, although it
tends to be sporadic-E skip, rather than F layer propagation we see
when there are more sunspots.

This week NASA released an article with details on upcoming solar
research initiatives, ranging from soon to 2015.  One that is
expected to launch in 2015 will place four satellites around the sun
and it will observe solar activity on the other side, facing away
from Earth.  See details 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 August 14 through 20 were 0, 0, 0, 0, 0, 0, and
0 with a mean of 0.  10.7 cm flux was 65.9, 65.3, 66.2, 66.5, 66.2,
67.3, and 65.9 with a mean of 66.2.  Estimated planetary A indices
were 5, 4, 5, 7, 23, 8 and 6 with a mean of 8.3.  Estimated
mid-latitude A indices were 4, 3, 4, 5, 15, 7 and 5 with a mean of


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