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ARRL Products:
DXCC, DXing resources and Call Sign listings(More)
DXing on the Edge -- The Thrill of 160 Meters
The ARRL DXCC List -- May 2009 Edition. DX Century Club (DXCC) rules and current entities listing. A "must have" for every DXer!
RSGB IOTA Directory -- Everything you need to know to enjoy collecting islands for the popular worldwide IOTA (Islands on the Air) award.
ARRL DX Century Club Program (DXCC) -- Award items, available from the DXCC Desk.
The DXCC Yearbook 2007 -- The DXing year-in-review: DXing activities, the Clinton B. DeSoto Cup and DXCC Challenge standings.
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The K7RA Solar Update
SEATTLE, WA, Dec 23, 2005--Average daily sunspot numbers dropped
about five points, and average solar flux was down about three points compared
to the previous week. Geomagnetic indexes also were down. Sunspot 838 currently
looks to be the most interesting as it is expanding rapidly and not quite in
the center of the visible solar disk--the area where it would have the most
effect on Earth. The predicted solar flux for the next few days is around 90--slightly
higher than it has been recently, but only by a few points. Sunspot 838 is
growing rapidly, but it probably will not emit any solar flares. Planetary A
index for December 23-26 is predicted at 7, 7, 10 and 7.
Alan Dujenski, KB7MBI, of Woodinville, Washington, found
an interesting PowerPoint presentation, "HF Radio Wave Propagation," by
ARRL South Carolina Section Technical Coordinator Marc Tarpley, N4UFP. Tarpley
has several
presentations on the South Carolina Section page.
More 10 meter propagation notes going back to the recent ARRL
10-Meter Contest. Don Strong, W7IUO, from Preston, Idaho, writes that he worked
VK, ZL and KH6 during the contest at around 1900 UTC (day not specified) and
worked W2 and W3 stations from 1800-1930 UTC. Being in Idaho, he was in hot
demand as a multiplier. I believe he did all of this using 40 and 80 meter
dipoles.
Red Haines, WO0W, in Minnesota sent in some links to
ionospheric maps created with ionosonde data on The Australian Space Weather Agency
Web site. He writes: "These maps are experimental and they map foF2 to the MHz,
not very high resolution. They display the locations of the ionosondes from the
data for the maps are derived."
The DXers Info Web
site has a link to data from individual ionosondes.
"Data is, of course, history by the time we can read it," Haines says. "In this
case, it is 40 minutes or more old. This site identifies the 'sondes from which
the above referenced maps are derived. While these sites are specific to North America, the links connect to similar products for the rest of the world."
He reminds us also that MUFs based on prediction
techniques are forecasts, while the actual ionosonde readings tell us what really
happened.
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 December 15 through 21 were 47, 47,
45, 45, 63, 53 and 45, with a mean of 49.3. 10.7 cm flux was 87, 85.8, 85.2,
85.6, 89.5, 87.8, and 86.5, with a mean of 86.8. Estimated planetary A indices
were 2, 5, 5, 3, 8, 16 and 8, with a mean of 6.7. Estimated mid-latitude A
indices were 2, 3, 2, 2, 6, 11 and 5, with a mean of 4.4.
Amateur solar observer Tad Cook, K7RA, Seattle, Washington, provides this weekly report on solar conditions and propagation. This report
also is available via W1AW every Friday, and an abbreviated version appears in The ARRL Letter. Readers may contact
the author via e-mail.
Page last modified: 11:25 AM, 23 Dec 2005 ET
Page author: awextra@arrl.org
Copyright © 2005, American Radio Relay League, Inc. All Rights Reserved.
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