[qrp-canada] FW: ARLP018 Propagation de K7RA

[rattray]

...fyi...

72/73 - Bruce ve5rc/ve5qrp - QRP-C#1, QRP-L#886, A1 Operator
            QRP-Canada - http://www.qrp-canada.com 
 



-----Original Message-----
From: W1AW Mailing List [mailto:w1aw-list-request at listserv.arrl.org] 
Sent: Friday, April 27, 2007 7:22 AM
To: rattray at accesscomm.ca
Cc: W1AW List:
Subject: ARLP018 Propagation de K7RA


SB PROP @ ARL $ARLP018
ARLP018 Propagation de K7RA

ZCZC AP18
QST de W1AW  
Propagation Forecast Bulletin 18  ARLP018
>From Tad Cook, K7RA
Seattle, WA  April 27, 2007
To all radio amateurs 

SB PROP ARL ARLP018
ARLP018 Propagation de K7RA

In the past few days sunspots have reappeared after six days of nothing.  In
April so far we've seen 18 days with 0 spots.  But currently a large
sunspot, number 953 is rolling into view.  A solar wind stream is also
expected to hit earth, causing geomagnetic upset on Saturday, April 28.  The
Australian Space Forecast Centre predicts quiet to unsettled conditions on
April 27, active to minor storm on Saturday, April 28, and active conditions
on April 29.  The U.S. Air Force predicts planetary A index from April 27
through May 1 at 5, 25, 15, 10 and 8.  Similar predictions from Geophysical
Institute Prague give us quiet conditions for April 27, active on April 28,
unsettled to active April 29, unsettled April 30, quiet to unsettled on May
1, and back to quiet on May 2-3.

Lots of news this week on the solar minimum and predicted solar maximum.  On
April 25, a Solar Cycle 24 Prediction Panel, consisting of members from
NOAA, NASA and other agencies looked at all available predictions and
attempted to reach a consensus.  It looks like the minimum between cycles 23
and 24 may not occur for another year, until March 2008, a year later than
recently reported.  The accuracy is expected to be plus or minus six months.
The peak of cycle 24 is expected to occur in October 2011 if there is a
large solar cycle, and August 2012 for a small cycle.  You can see their
statement at, http://www.sec.noaa.gov/SolarCycle/SC24/Statement_01.html.

Many people sent links to articles about this.  Frank Donovan, W3LPL of
Glenwood, Maryland sent a couple of links, including one with a graphic
representation of a range of predictions at,
http://www.sec.noaa.gov/SolarCycle/SC24/ssn_predict.gif.  Also check
http://www.sec.noaa.gov/SolarCycle/SC24/ for other info, including
PowerPoint presentations.  If you don't have PowerPoint, you can find a free
PowerPoint viewer to download for Mac or Windows by searching for the two
words PowerPoint Viewer in Google, or any other search engine.

An AP story is at,
http://seattlepi.nwsource.com/national/313152_solar26.html, and on the web
at, http://www.space.com/scienceastronomy/060818_sun_cycle.html link.

We received a large volume of mail this week, and hope to get to more of it
in the next bulletin.  Among reports was some unusual 6 meter backscatter
propagation observed by Bill Van Alstyne, W5WVO of Rio Rancho, New Mexico on
April 21.

I'll let Bill describe it: "Greetings from New Mexico, DM65. Just finished a
very unusual opening off of a pre-season Es cloud in northern Mexico,
approximately 2315-0100z. Many central Mexican stations in XE1/XE2 with 59++
sigs, but the real news was the amazing strength of the backscatter signals
coming in from Arizona, New Mexico, Utah, Texas, and California, all peaking
with the beam pointed due south. Was able to work a couple of new close-in
grids in AZ, as well as many other grids I already had. Strongest
backscatter signals were from Bob, W7UT, in southwest Utah; Bud, N7CW, in
Prescott, AZ; and Tommy, W7RV, in Scottsdale, AZ. All were consistently
56/57 until the propagation began to weaken around 0030z."

Bill continues, "This is by far the strongest backscatter I've ever heard on
6M. As a rule, Es clouds (due to their very thin, flat
architecture) are very poor backscatter producers; the only previous
backscatter I've ever worked off of 6M Es was extremely weak. This
backscatter propagation was ragchew quality, and lasted virtually without
QSB for over an hour."

Also this week we saw some of the early 3-D images from the NASA STEREO
satellites.  To view in 3-D, you need those paper glasses with a red filter
covering the left eye, and cyan filter over the right eye.  You can see the
images at,
http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html.
They also have info on where to find the glasses.  I found mine for well
under a dollar at Science, Art and More, a shop that sells products for
science education in my neighborhood.

I must admit I was a little disappointed, but only a little.  At the
distance these solar images are taken, the depth effect of the sun shows it
as very close to a perfect sphere, in my estimation. Perhaps I was hoping
for detailed looks at the surface with exaggerated three-dimensional effects
that would enhance the perception of depth and detail.  But I have no doubt
that the images shown on that page are probably accurate, more so than what
I had imagined.

If you would like to make a comment or have a tip for our readers, email the
author at, k7ra at arrl.net.

For more information concerning radio propagation, see the ARRL Technical
Information Service at, http://www.arrl.org/tis/info/propagation.html. For a
detailed explanation of the numbers used in this bulletin see,
http://www.arrl.org/tis/info/k9la-prop.html. An archive of past propagation
bulletins is at, http://www.arrl.org/w1aw/prop/ . Monthly propagation charts
between four USA regions and twelve overseas locations are at,
http://www.arrl.org/qst/propcharts/.

Sunspot numbers for April 19 through 25 were 0, 0, 0, 0, 0, 0 and 14 with a
mean of 2. 10.7 cm flux was 68.3, 68.5 68.7, 68.9, 69.1, 73.2, and 76.5,
with a mean of 70.5. Estimated planetary A indices were 6, 3, 2, 10, 18, 4
and 5 with a mean of 6.9. Estimated mid-latitude A indices were 4, 2, 2, 8,
10, 5 and 4, with a mean of 5. NNNN /EX


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