[Waverley ARS] Fwd: ARLP036 Propagation de K7RA

Sat Sep 5 00:02:48 UTC 2009

Hi Raffy

Is this service available only to ARRL members or can any interested 
WARS member sign up for themselves?

73 Simon

raffy at raffy.net wrote:
> Hi Members,
>
> Thought some members might be interested in this. If sufficient members
> respond, I will auto forward weekly.
> 73
> Raffy VK2RF
>
>
> ---------- Forwarded message ----------
> From: ARRL Web site <memberlist at www.arrl.org>
> Date: Sat, Sep 5, 2009 at 1:52 AM
> Subject: ARLP036 Propagation de K7RA
> To: arrl at raffy.net
>
>
> SB PROP @ ARL $ARLP036
> ARLP036 Propagation de K7RA
>
> ZCZC AP36
> QST de W1AW
> Propagation Forecast Bulletin 36  ARLP036
> >From Tad Cook, K7RA
> Seattle, WA  September 4, 2009
> To all radio amateurs
>
> SB PROP ARL ARLP036
> ARLP036 Propagation de K7RA
>
> This week we saw another one of those fast-disappearing sunspots.
> It lasted just two days, over the last day of August and the first
> of September.  No other sunspots were observed during the month of
> August.
>
> The monthly average of the daily sunspot number, January through
> August 2009, is 2.8, 2.5, 0.8, 1.3, 4, 6.6, 5.1 and 0.4.
>
> The three-month moving averages of daily sunspot numbers for October
> 2008 through July 2009 were 4.5, 4.4, 3.6, 2.2, 2, 1.5, 2, 4.2, 5.2
> and 4.  This takes into account all the daily sunspot numbers for
> September 2008 through August 2009, and those numbers are for the
> center months of each of those three month moving average periods.
>
> The latest figure, for July 2009, is an arithmetic average of all
> daily sunspot numbers for June through August.  The previous figure,
> for June, is an average of daily sunspot numbers for May through
> July.  In other words, sum all the daily sunspot numbers from May 1
> through July 31, which equals 478.  Divide by 92, which is the
> number of days in those three months, and it equals approximately
> 5.196, or 5.2 rounded off.
>
> For June and July we saw the moving average drop from 5.2 to 4, and
> if September has no sunspots after the one on September 1, then the
> three-month average centered on August will be 2.
>
> So what is coming up in the near term?  Continued low solar flux and
> possibly no sunspots.  Geophysical Institute Prague predicts quiet
> to unsettled conditions for September 4 and 8.
>
> We received many tips and comments this week about the lack of
> sunspots, and a link at,
> http://science.nasa.gov/headlines/y2009/03sep_sunspots.htm to an
> article titled, "Are Sunspots Disappearing?"
>
> It concerns the work of Livingston and Penn at the National Solar
> Observatory in Tucson, and their observation that magnetic fields
> from sunspots are declining.  It is important to note that most of
> their measurements are after the peak of Cycle 23, so this may be
> normal during the decline of a cycle, not just this one.  Also, when
> they say there may be no sunspots by 2015, this is an extrapolation.
> Since we do not know what has happened in previous cycles regarding
> this more accurate measurement of magnetic fields from sunspots, it
> may be unrealistic to assume that the trend will continue.
>
> NW7US interviewed Dr. Penn this week in his podcast, which you can
> download from http://tinyurl.com/NSWARPP-E04.  Very interesting
> interview with lots of details on his research.
>
> Regarding sunspots disappearing, check out the comments from K6SGH
> on his web page, http://www.k6sgh.com/index.html.
>
> An interesting comment came from Jim Williams, K5NN of Wichita,
> Kansas.  Jim wrote, "As an old retired Electrical Engineer and a ham
> dating back to 1952, I'm wondering what the explanation for
> consistent long skip might be. I have been involved in an informal
> net on 75 meter SSB for close to 50 of those years (2 uncles and
> others, lots of silent keys now) before going to work-about 7AM
> central time. We never used to have consistent problems with long
> skip, now most mornings short skip is 200 miles. As I have been
> active through several sunspot minimums, the extended periods of
> long skip around daylight was never such a problem. Lately it has
> taken a kilowatt to be just above the noise on a hundred mile path,
> the path normally has been good, even at 100 watt level. Is a good
> plausible explanation in existence for these conditions?"
>
> This brings to mind an August 2007 email from Jerry Reimer, KK5CA of
> Spring, Texas.  Jerry mentioned that short skip on low frequencies
> depends on NVIS (Near Vertical Incidence Skywave) propagation.  The
> propagation out to 100 miles depends on the high angle component of
> the antenna radiation bouncing or refracting off the ionosphere
> overhead.  Longer skip depends on lower angle radiation.  Jerry
> mentioned that for reliable short skip propagation, the frequency
> used should be only 50-80 percent of the fMUF.
>
> Recent fMUF values from ionosonde data may be found at
> http://www.swpc.noaa.gov/ftpmenu/lists/iono_day.html.  If I click on
> the Boulder (Colorado) data, I see that over the past day the fMUF
> above Colorado may not be high enough to support short skip on 75
> meters.
>
> Another source of real time info are the HAP (Hourly Area
> Predictions) charts at http://www.ips.gov.au/HF_Systems/6/6/1.
> Select a location from the drop down menu, and you see a map showing
> propagation for various frequencies from that location.
>
> Go to http://www.ngdc.noaa.gov/stp/IONO/ for more information about
> ionosondes.
>
> We got a report this week from Luke Steele, VK3HJ, in Benloch,
> Victoria, Australia.  He will soon see the Spring equinox down under
> (our Autumnal Equinox in the Northern Hemisphere is September 23,
> nearly three weeks from now), and note at the end of his comments
> that he echoes K5NN regarding 80 meters.
>
> "Just thought I'd drop a line and offer a DX perspective from my
> modest station in central Victoria, 50 miles NW of Melbourne."
>
> "My main antenna here is a 520 foot doublet at 60 feet, with open
> wire to the shack and a 1/4 wave vertical for 40m."
>
> "Conditions the past few months have been very quiet, with very
> little happening on 20m and up, although I have still been working
> DX on CW and PSK most evenings (0800-1400z). There are nearly always
> Russians to be seen on 20m PSK afternoons and evenings here."
>
> "40 and 30m provide continuing interest, particularly CW and PSK.
> Contacts to the Pacific Islands and S Asia and JA are available in
> the evenings when I get on the air. Some Indian Ocean contacts to be
> had, recently with VQ9JC and VQ9LA on Diego Garcia on 20 and 40m,
> and 4S7NE in Sri Lanka."
>
> "75m SSB looks average for this time of year with USA on most
> evenings. 40m CW to USA is mostly good, and SSB is light. I've also
> been hearing some North America on 160m CW most evenings, and have
> worked a couple. Top band OK out to Western Australia, Queensland
> and the western Pacific Islands (out to about 2500mi)."
>
> "Nothing much from Europe, Africa, South America and the Caribbean
> for some months."
>
> "Local club nets on 80m in the evenings have sometimes been
> difficult, over the past few months with close stations weak, those
> beyond about 500mi loud. There's also DX to be had in the mornings
> here, but I usually miss that, not being a 'morning person'!"
>
> "So, there is still DX to be had, but operating modes and methods
> need to change to suit."
>
> Thanks, Luke!
>
> Bob Karpinski, WB8B from Clinton Township, Michigan has been having
> fun running QRP on 17 meters.
>
> Bob wrote, "There was a very sporadic opening with very good signals
> from the far western edge of EU on 17m from 2300-0000z from
> Michigan. CT1JOP was worked on 17m CW with only 1 watt on 8/27/09
> 2330z! He lowered his power to 5w during the QSO and we had a 2-way
> QRP contact with 559 signals."
>
> Steve Ickes, WB3HUZ of Lightfoot, Virginia wrote: "Despite the lack
> of sunspots, I've been enjoying world wide DX on 40 meters daily. 80
> meters has been more active in the last few weeks with very strong
> signals (5-9+20) from many stations out of Europe. It can only get
> better as the static begins to subside with fall coming."
>
> 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 web page 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/.
>
> Instructions for starting or ending email distribution of this
> bulletin are at http://www.arrl.org/w1aw.html#email.
>
> Sunspot numbers for August 27 through September 2 were 0, 0, 0, 0,
> 12, 12, and 0 with a mean of 3.4.  10.7 cm flux was 67.7, 67.9, 68,
> 67.2, 68.3, 69.1, and 68.2 with a mean of 68.1.  Estimated planetary
> A indices were 5, 2, 2, 19, 5, 4 and 3 with a mean of 5.7.
> Estimated mid-latitude A indices were 4, 2, 2, 12, 5, 2 and 2 with a
> mean of 4.1.
> NNNN
> /EX
>
>
>
>
>   