[South Florida DX Association] ARLP038 Propagation de K7RA

[Bill Marx]

 SB PROP ARL ARLP038
> ARLP038 Propagation de K7RA
> 
> The Autumnal Equinox for the Northern Hemisphere will occur on
> September 23 this year (at 0402z). We've been moving from summertime
> propagation conditions to fall, which is generally a better time for
> HF propagation, except for the lack of sporadic-E skip.
> 
> On 20 meters, instead of intercontinental openings into the evening,
> we see improved conditions well before dark. For instance, comparing
> projected conditions for this weekend from the East Coast USA to
> Europe, with conditions in early July, 20 meters was marginal during
> the morning and mid-day, but became better late in the day.
> Conditions between Pennsylvania and Germany around July 5 show a
> projected jump in signal levels around 2200z, then excellent
> propagation until around 0700z.
> 
> But for mid-September 20 meters over the same path has rising
> signals from morning until early evening, with signals dropping
> after 2300z. 17 meters over the same path looks very good this
> weekend from 1230z until 2130z, but for early July the chances of a
> good path were much lower, except for a brief period around
> 0000-0030z.
> 
> Average daily sunspot numbers rose over the past week by 19 points
> to 44.3. Geomagnetic conditions were quiet every day. For the next
> week Geophysical Institute Prague predicts quiet conditions for
> today, September 15, then quiet to unsettled on the 16th, unsettled
> geomagnetic activity on the 17th and 18th, then quiet on September
> 19-21. The U.S. Air Force spaceweather operation predicts planetary
> A index (a measure of geomagnetic activity) for September 15-21 at
> 5, 10, 12, 15, 8, 5 and 5.
> 
> Steve Hammer, K6SGH of Santa Barbara, California wrote asking about
> a source for an archive of daily sunspot numbers that he might
> import into a spreadsheet. Al Woodhull, N1AW of Amherst,
> Massachusetts had a similar request. One handy source for this,
> which is easy to update using this bulletin, is the free Solar Data
> Plotting software from Scott Craig, WA4TTK. The program stores the
> daily sunspot number and solar flux going back to the late 1980s in
> a file called graph.dat.
> 
> Scott's program is at, http://www.craigcentral.com/sol.asp, and
> there is also a separate update to the data file with numbers up
> through the end of August. You can update the file
> semi-automatically by saving this weekly bulletin in a plain-text
> file, then using the software to read the file and suck up the data.
> To bring the current file up to date would only require a file made
> from this bulletin and another from last week's edition.
> 
> Al and Steve, mentioned in the previous paragraph, each have their
> own websites highlighting some of their interesting activities. See
> Steve's at, http://www.k6sgh.com/, and don't miss his Moxon Antenna
> site at, http://moxonantennaproject.com/. Al's website is,
> http://minix1.woodhull.com/asw/.
> 
> Gary Nixon, WA6HZT of Fair Oaks, California and Andy Gudas, N7TP of
> Amargosa Valley, Nevada both sent in references to an article
> claiming that thunderstorms actually affect the ionosphere and radio
> propagation (other than causing QRN, of course). Read it at,
> http://www.cnn.com/2006/TECH/space/09/13/space.storms.reut/index.html.
> 
> Dick Bingham, W7WKR of Stehekin, Washington sent in a quote
> concerning 160 meters from Wolf Ostwald, DF2PY. Wolf write, "This
> years West Coast window opened about 3 weeks earlier than in the
> last years. K7RL and W1YY/7 made it into EU today about 45 min and
> 25 min prior to local sunrise. Their sigs were fantastic for topband
> standards, even good enough for 'ragchewing.' I take this as a good
> omen for the new season and it repeatedly shows again the
> superiority of the CW mode to master difficult paths under any
> circumstance."
> 
> And finally, Bill Isakson, AC6QV of El Cerrito, California wrote
> this about 17 meters. He writes, "I thought, since you just now
> indicated a software result that not much should happen above 20
> meters, that I should tell you that 17 meter activity has been great
> recently. Earlier this week I had QSO with a station in San
> Francisco, Argentina from here in Berkeley near San Francisco,
> California, for example, on my way home from work around 5 PM, that
> is, mobile on a Hamstick."
> 
> Bill continues, "His S9 CW signals were mildly strong and clean in
> this electrically noisy environment, though mine at his end were
> weak (559 he said, but I had to make several repeats, so it was
> probably 539). I would give you his call sign, but my email is
> nowhere near my logbook. I can say he was a powerhouse station. The
> 17 meter band has generally been open most of the afternoons here
> and I have heard VK land as well. The radio I am using for mobile
> does not have any special filtering in use either, so CW and USB
> have been through the same set of wide filters."
> 
> 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/ .
> 
> Sunspot numbers for September 7 through 13 were 39, 49, 51, 50, 42,
> 41 and 38 with a mean of 44.3. 10.7 cm flux was 86.7, 87.2, 85.5,
> 87.3, 84.6, 84.1, and 82.9, with a mean of 85.5. Estimated planetary
> A indices were 8, 4, 2, 6, 8, 4 and 6 with a mean of 5.4. Estimated
> mid-latitude A indices were 5, 4, 1, 5, 7, 2 and 3, with a mean of
> 3.9.
> NNNN
> /EX
> 
>