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Propagation Forecast Bulletin 47 ARLP047
From Tad Cook,
K7RA
Seattle, WA November 20, 2009
To all radio amateurs
SB
PROP ARL ARLP047
ARLP047 Propagation de K7RA
Sunspot activity seems to
be increasing steadily of late. Daily sunspot numbers for November 5-19 were 15,
16, 11, 0, 14, 13, 11, 11, 0, 0, 11, 12, 0, 29 and 30.
Sunspot 1029 made
its trip around the Sun and has re-emerged as sunspot 1032, and a new sunspot
1033 has come over the eastern limb.
This steady appearance of sunspots has
raised the MUF over many paths, and 15 meters is beginning to open
regularly.
In the Southern Hemisphere, which gets more solar radiation
this time of year, you can see a pronounced effect on the foF2 reading in
the
afternoon (local time is UTC+6.5 hours) on the web site
http://www.swpc.noaa.gov/ftpdir/lists/iono_day/Cocos_Is_iono.txt.
This is
a measurement taken with an ionospheric sounder on Cocos-Keeling Islands in the
Indian Ocean, 12.5 degrees South
latitude and 96.8 degrees East longitude.
The instrument sweeps a radio signal across the HF spectrum, beamed straight up
to the
ionosphere overhead, and it measures the strength of the signal
bouncing back to determine optimum frequency. You can see during
mid-day foF2
is going above 10 MHz.
Of course, your results may vary. The effect was
pronounced from 0600-1400z on November 19, and not quite as enhanced on November
20,
0700-1000z. Unfortunately, these ionosonde records don't go back but a
day or two. You will see less effect this time of year in the
Northern
Hemisphere, as seen at a record of ionosonde data in Italy on the
http://www.swpc.noaa.gov/ftpdir/lists/iono_day/Rome_iono.txt
site. On
the http://www.swpc.noaa.gov/ftpdir/lists/iono_day/Chilton_iono.txt site see
similar data taken in the UK.
At
http://www.swpc.noaa.gov/ftpdir/lists/iono_day you can check a list of links for
68 different locations, but some of them seem
inactive. For instance, after
months of checking, I have never seen a bit of ionosonde data from Eglin Air
Force Base in Florida, in the
file "Eglin_iono.txt."
Another
interesting tool to see varying MUF around the world, updated every five
minutes, is at, http://www.spacew.com/www/realtime.php.
The contour lines
show the MUF over that particular area. During the day recently some areas over
Africa are going above 30 MHz.
This weekend is the ARRL SSB Sweepstakes
Contest, and conditions are expected to be good for this popular domestic
operating event. There
is a possibility of some disturbance from unsettled
geomagnetic conditions, possibly peaking on Saturday. Predicted planetary
A
index for November 20-24 is 10, 15, 10, 6 and 5. Possible mild disturbance
on Saturday would be from a wind stream from a coronal
hole that currently
faces Earth.
Predicted solar flux for the near term is 78 for November
20-21, 80 for November 22-26, and 70 on into early December.
Evan Rolek,
K9SQG of Beavercreek, Ohio has been noting stateside and short skip 40 meter
conditions this year. Back on April 20, he wrote
"Over the past month, 40
meters has been dismal for daytime net activities. In addition to storm-related
static, signals range from
"normal" to 20-30 dB below normal. Interestingly,
I'm experiencing one-way skip with certain stations, but not all. For example,
a
station that I share net control with on the Georgia 40 Meter Traders' Net
on Sunday morning is down something like 15-20 dB on my
S-meter. Still solid
copy but he is unable to copy me at all."
But recently Evan notes an
improvement. On November 16, he wrote observations "based upon some 40 meter
swap and technical net
participation. Recent weeks have shown an improvement
in signal strength and areas of coverage in the 1400-1500z and 2000-2100z
time
frames (morning and afternoon on North America's East Coast). Signals
are up 10-30 dB (yes, ten to thirty decibels) and the areas
of coverage have
improved. Close-in regions under 200 miles that were almost uncopyable for the
past several months now have signals
that are 10-35 dB over S9. Talking with
stations in Minnesota, Louisiana, New Hampshire, Florida, Mississippi, etc. are
becoming
more frequent. I hope this is the sign of improvements for a long
term basis."
Check out http://www.physorg.com/news177872248.html to read
an interesting article about a solar tsunami, and how STEREO gives
a
3-dimensional view to better judge the height of solar
disturbances.
Larry Godek, W0OGH of Gilbert, Arizona says conditions are
improving.
Larry writes, "First of all, I run only 100 watts here and all
antennas except for the 20 meter beam at 30 feet are dipoles. DX has
been
quite good of recent.
"For me to work anything on 20 meter SSB which is
normally KW Alley, is something that hasn't happened for years and years around
here.
However as I've worked ZB2EO, 6W/EI6DX, T30KI, ZS6JPY (40 meter SSB)
and TL0A which is not impressive to some but it sure gets
my
attention.
"Surprisingly the African contacts have been in the
morning hours, who I normally can't work, much less hear, until after 2100Z.
Just
too much RF blocking going on to the east of me.
"This morning on
the ZB2 station, I had called him a few minutes earlier but again the east coast
was doing all the talking. Shortly
thereafter I heard him calling CQ DX with
no answers. While signals were only about 5-5 both ways, it was a clear path
with no other
stations heard on the frequency. Quite a surprise.
"Last
night, November 13 (0346z) ZS6JPY was heard calling CQ on 40 SSB. No one
appeared to be returning his calls so I gave him a
shout. Again using 100
watts and a weird 40 meter dipole antenna configuration I was able to work
him.
"Kind of reminds me of the days back in the late 50s when you could
load up the bedspring and work the world. WOW! Things are
improving!
"Lots of DX on the 30 meter band from Europe as well as the
Caribbean region and Pacific. The CW bands have been much better.
I've even
been able to work DX on 17 meters with the 20 meter beam, greatly reduced power
of course, but never the less, propagation was
good enough for it to
happen."
Vic Woodling, WB4SLM of Centerville, Georgia (EM82dp)
experienced some interesting tropospheric propagation earlier this week.
Vic
wrote, "Tropo last night (14-15 Nov) early this morning across the
southeast to the southwest. Couple examples: worked our old friend
Pat WA5IYX
(San Antonio, Texas EL09ql) on 2 meter CW, 909 miles. Also made a "sweep" from 6
meters, 2 meters, 222, 432, 902, 1296,
and 2304 MHz with OM Bill W3XO/5
(Kerrville, Texas EM00kd), 925 miles. I 'think' but really can't remember if
this was my personal
best on 6 meter tropo, but should be. I know it was (my
best) on 2304 902 MHz. In chatting with Bill W3XO and Drew KO4MA (New
Port
Richey, Florida EL88pg) early this AM they said they had a 997 mile
contact on 222 MHz."
After this weekend, when we have the ARRL SSB
Sweepstakes Contest, the following weekend (November 28-29) is the CQ Worldwide
CW DX
Contest, followed by the ARRL 160 Meter Contest December 4-6, then the
ARRL 10 Meter Contest, December 12-13.
This weekend we should see some
propagation on 15 meters over the domestic paths for the contest. For instance,
Dallas to Seattle
should be good on 15 meters 1630-2130z, 10 meters possibly
1800-2000z. California to Ohio on 15 meters should work 1600-2130z,
and
possibly 1630-2030z. Dallas to Boston looks good for 15 meters 1600-1930z, and
Dallas to Vancouver looks good on 15 meters
1630-2130z. Atlanta to Edmonton,
Alberta also looks good for 15 meters 1630-2030z, with 10 meter possible
1730-1900z.
James French, W8ISS sent in a comment in response to the info
about backscatter in last week's bulletin.
He writes, "We had this exact
thing happen on ten meters Just before the November Sweepstakes started November
7th.
"Gave a call out asking if the frequency was in use, then started
calling CQ. With the newly installed tri-band beam pointed west, a
local
station about ten miles away answered back. He said we were weak so we swung the
beam East (his direction) and lost him totally.
Swung the beam back West
again and there he was. We were in Ann Arbor, MI and the other gent was in
Belleville, MI. Was using W8ISS
from the Red Cross station.
"I was
wondering if we had installed the beam backwards as we had just gotten it up on
the 65' tower about two weeks ago and was
getting ready for Sweepstakes that
weekend. Jay, WB8TKL, told me about how it was probably backscatter. I wouldn't
have thought it
possible that close, but there it had happened in front of
me."
Finally, Chris Kelly, K0PF tells a story about operating mobile
recently, and experiencing some of that old shortwave magic.
"My note
regards an interesting contact I had the other night.
"I was driving to
Colorado State University about 9 PM to pick up my son (K0PFJ) who had a late
exam, and I decided to switch on the
IC-706MK2G in the pickup and see if
there was anything happening in this lowest of sunspot days. I heard and worked
a station on
Vancouver Island, who was very kind and turned his 20 Meters
beam my way because he heard a mobile.
"He was working a lot of JAs who
were barely audible to me. I tuned around a bit and heard an interesting accent
and called, receiving a
5/7 report from ZL1BOS. I thought this was quite a
feat from a 100 watt mobile (he must have a good antenna and
receiver).
"A few minutes later and all the JAs had faded out and 20
seemed dead. I dropped to 40 meters, and promptly heard a ZS1, about 5/5.
By
the way, the antenna on the truck was a Hustler whip using a 20 meter resonator,
tuned with a SGC antenna coupler. Not even the
right resonator for
40.
"I have been a ham for almost 3 sunspot cycles, and while I am not
very active right now (obviously busy raising a family), I am still
amazed at
the propagation that opens up even at the bottom of the cycle. Hearing the
opposite side of the Earth via two paths on the
same night from a mobile
station. Wow!"
If you would like to make a comment or have a tip for our
readers, email the author at, [email protected].
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 November 12
through 18 were 11, 0, 0, 11, 12, 0, and 29 with a mean of 9. 10.7 cm flux was
73.2, 74.1, 74.8, 75.1,
76.2, 77.2, and 76.1 with a mean of 75.2. Estimated
planetary A indices were 1, 2, 5, 4, 1, 1 and 2 with a mean of 2.3.
Estimated
mid-latitude A indices were 0, 2, 3, 3, 0, 0 and 2 with a mean of
1.4.
NNNN
/EX