ARRL

ARRL Propagation Bulletin ARLP047 (2009)

SB PROP @ ARL $ARLP047
ARLP047 Propagation de K7RA

ZCZC AP47
QST de W1AW  
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, k7ra@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 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