Propagation
dxAce
SEATTLE, WA, Mar 17, 2006--The recent news regarding
projections for a huge solar Cycle 24 brings in more mail daily. All
of us want to see lots of exciting space weather over the next
decade, but not everyone is convinced. While I wouldn't count him
among dissenters, Jon Jones, N0JK, sent in this article from a year
ago (several readers mentioned this) that predicts a very small
Cycle 24 and also claims to use a successful prediction method.
Read it and weep (or not).
Several people wrote this week to say they were enjoying the quiet
conditions. Without many sunspots, the maximum usable frequency
(MUF) is low, but there is less noise and absorption.
Mike Schatzberg, W2AJI, writes:
"The low solar activity seems to have produced some exceptional
conditions on 20 meters within the last week. The band has been
most reliable all day long here in western NC . . . Propagation is marked by
very low
atmospheric noise. Weaker stations are easily pulled out, provided QRM
permitting. I am
working great numbers of QRP stations, worldwide. Although we all are hoping for
the beginning
of the new cycle and greatly improved propagation, I do well remember the QRM
that
accompanies great propagation. Things don't really seem nearly so poor as in the
bottom of
other cycles which I have experienced. Maybe it's much better equipment and
antenna systems
than in years gone by."
I suspect Mike's better antenna system may help. Check out the 5-element 20
meter Yagi.
Mike also writes:
"Early morning contacts include strong European propagation, which continues
well into the
later afternoon. Signal reports of well over S9 are common, from both sides.
Propagation into
India, and Southeast Asia is quite good in the early morning times also. Regular
contact is found
with Jakarta, Indonesia, also. Later afternoon, the long path opens to the South
Pacific, with
unbelievable VK propagation. Yesterday's contacts, including VK3OK, VK2ZF and
many others,
produced reports of from 20 to 25 DB over S9 in both directions. The band goes
longer, short
path to the Pacific about 2 to 3 hours after dark. KH7F has his usual S9 signal
here at my
location. South America remains strong for most of the evening."
Orrin Brand, K9KEJ, is using a ground-mounted vertical antenna on 20 meters with
no radials.
He writes:
"Late mornings in the Chicago area have been rather unusual of late. I'm able to
hear and work
Africa, Eastern Europe and VK land, all in a matter of minutes on 20 meters.
European signals
run anywhere from S7 to 10/9, while east and West African stations run a solid
S9. The VKs and
ZLs go anywhere from S5 to S8--all on the vertical."
Average daily sunspot numbers and solar flux values were down just slightly this
week when
compared to last, and the geomagnetic indexes were up just a bit. We only saw
one day with
zero sunspots, and there weren't any really stormy days with high geomagnetic K
and A indices.
The prediction for the next few days is a solar flux value of 75, and, in fact,
that continues in
Thursday's prediction from the US Air Force for the next 45 days. The USAF also
predicts
Sunday, March 19, will be a day of geomagnetic activity, with a planetary A
index projected to
reach 20. The five-day projection for planetary A index from March 17-21 is 8,
8, 20, 15 and 12.
This slightly higher activity is based on what was occurring in the area of the
sun that will be
facing us this weekend, looking back to February 19-22 when the planetary A
index was 6, 20,
17 and 12.
This projection for geomagnetic activity seems shared this week by Geophysical
Institute
Prague, which projects quiet conditions for March 17, 22 and 23, quiet to
unsettled for March
18, unsettled for March 20 and 21, and unsettled to active on March 19.
For more information concerning propagation and an explanation of the numbers
used in this
bulletin see the ARRL Technical Information Service Propagation page. An archive
of past
bulletins is on the ARRL Web site.
Sunspot numbers for March 9 through 15 were 12, 12, 0, 18, 14, 34 and 22, with a
mean of 16.
10.7 cm flux was 72.9, 72.2, 74, 73.2, 72.6, 73.6, and 74.2, with a mean of
73.2. Estimated
planetary A indices were 4, 12, 12, 6, 3, 4 and 7, with a mean of 6.9. Estimated
mid-latitude A
indices were 3, 9, 9, 3, 2, 2 and 6, with a mean of 4.9.
(K7RA, ARRL)
dxAce
Michigan
USA