ARRL

Register Account

Login Help

ARRL Propagation Bulletin ARLP054 (2008)

SB PROP @ ARL $ARLP054
ARLP054 Propagation de K7RA

ZCZC AP54
QST de W1AW  
Propagation Forecast Bulletin 54  ARLP054
From Tad Cook, K7RA
Seattle, WA  December 26, 2008
To all radio amateurs 

SB PROP ARL ARLP054
ARLP054 Propagation de K7RA

Snow has fallen all week here in Seattle, and the Sun is still void
of spots.  We last saw sunspots on December 10-12.  Solar flux (a
measure of 2.8 GHz radio energy from our Sun) has been running
between 68-69 for weeks, except for December 10-12, when it was
70-71, coincident with the appearance of sunspots.  Now NOAA and the
US Air Force are predicting solar flux for today, December 26, at
70, and December 27 through January 5 at 71.  Perhaps this indicates
sunspot activity rotating into view.

On December 7, a possible sunspot group was detected on our Sun's
far side, and on December 23 another spot, this time in the southern
hemisphere on the far side of the Sun.

The same NOAA/USAF forecast shows more of the very quiet conditions
we've seen for some time now, with a planetary A index at 5.  Some
unsettled conditions are forecast for January 1-2, with the
planetary A index rising to 8, then 10, before settling back to 5
again.

Geophysical Institute Prague predicts quiet conditions continuing
December 26-30, quiet to unsettled December 31, and unsettled
January 1.

Duane Heise, AA6EE of Ramona, California is interested in
calculating sunrise/sunset times for his location.  A good resource
is the US Naval Observatory.  For details see,
http://aa.usno.navy.mil/data/docs/RS_OneDay.php.

If you need to convert a location from decimal notation to
degrees/minutes/seconds, it is easy.  For instance, suppose you have
latitude of 47.857 degrees.  Multiply .857 by 60 to get 51.42
minutes; multiply .42 by 60 to get 25.2 seconds.  Now you have 47
degrees, 51 minutes, 25 seconds.

Since we have rounded the seconds off to 25, we can go the other
direction to demonstrate the method for deriving the corresponding
decimal notation.  For example, (25/3600)+(51/60)+47 is
approximately 47.856944 degrees.

We've had more comments about the 10 meter contest of a couple of
weeks back.  Ken Wood, N5NX of The Colony, Texas uses a very simple
10 meter antenna and about 90 watts.  He wrote, "Sunday morning of
the 10m contest, there was a strong opening from Dallas, TX area to
the north. I easily worked MN, MI, OH, IN, and PA."

Dave Stucky, AB7Q of Bend, Oregon writes, "Here in Central Oregon,
the conditions were a pleasant surprise. Saturday morning started
with K7ES in Hillsboro (Portland) with a strong signal here in Bend
about 150 miles away. His signal was heard throughout most of the
openings on both days. After that some S.F. Bay Area stations were
heard and worked, then nothing but Colorado stations, most very
strong. The Es then swung south with nothing heard but AZ. Behind
the AZ stations were a few LU and PY, I worked LU1HF. Then briefly,
the east coast was there and I worked SC, GA and KS. This was all
between 8am and 12pm PST. The pattern was very similar on Sunday
morning with some Southern California stations there with Arizona.
Again toward the end of the opening LS1D was worked both CW and
phone. My assumption is that the Es to South America was multi-hop
in conjunction with equatorial Es. No real activity to speak of in
the evenings, though some occasional scattered voices were heard. I
was reading about Es on the computer while I was casually operating.
What an amazing propagation mode! All in all, in casual operation I
worked 60 stations in 10 states (OR, CA, AZ, WY, CO, UT, NM, KS, SC,
GA) along with LU and PJ2. I heard the CX station pile-up but did
not get through. I was using 75 watts to a tri-bander at 55 feet."

Jon Jones, N0JK of Wichita, Kansas ran 5 watts in the 10 meter
contest to the same 100 foot wire tacked to his house that he used
for the 160 meter contest.  He wrote, "I could work most stations
heard on Es and even a few on meteors if I timed my calls on
over-dense bursts. Nice Es opening Saturday evening to Florida.
Sunday all day Es starting at 1500 UTC to northeast, with K1ZZ CT
starting things off. Later Es to Atlantic seaboard and southeast
states. Best DX was PJ2T and LU1HF! They sounded like an Es to F2
type link. I had strong Es to LA and Florida the same time they were
in. I almost logged PY3MHZ, he heard me but faded as he gave his
exchange. Thanks also to XE2S and XE2/N7DD for Mexico. Very loud Es
to Colorado at the end of the contest. K0FX, K0MF, W0ETT, etc 599+
60! Ran off 11 Colorado Qs in 5 minutes. Like shooting ducks in a
barrel for a flea power station. Picked up KD0S SD and K0PK MN in
the last few minutes for new mults. Lotsa radio fun for 5 watts and
a 4 dollar wire antenna."

You can read soapbox comments for the 10 meter contest at,
http://www.arrl.org/contests/soapbox/index.html?con_id=164.

For regular weekly updates of 10 meter activity in Europe, check
Tony's 10 Meter report at,
http://www.southgatearc.org/bands/10metres/.

Bill Van Alstyne, W5WVO of Rio Rancho, New Mexico sent in a piece on
working meteor scatter on 6 meters with the WSJT digital mode, which
he has been doing since the beginning of 2008. Bill wrote, "While we
had a fairly decent Summer sporadic-E season in 2008, there were of
course those awful OTHER months of nothing, nothing, nothing -- or
so I had always thought. Actually, there is propagation on 6 meters
24 hours a day, 365 days a year, due to tiny meteoric particles
falling to earth and burning up. Because most of these meteors are
tiny and relatively low-velocity, the ionization trails they leave
only last for a few tenths of a second, not enough time to get any
kind of message across using SSB or CW. But with FSK441, Joe
Taylor's MS-optimized digital mode, a complete exchange can be
transmitted, propagated, and decoded in as little as 150 ms. Yes,
that's 0.15 seconds."

He continues, "Meteor showers, when they are good, can produce
ionization "burns" that last tens of seconds -- sometimes even for
minutes! But for reasons not entirely understood, the known meteor
showers that used to produce spectacular VHF propagation for a few
days at regular intervals throughout the year just aren't doing so
these days. More and more, therefore, MS communication takes place
using the new WSJT digital modes and "pings" -- ionization trails
that persists for a second or less and are probably made by meteors
about the size of a grain of sand -- or a spec of dust! This is
where MS becomes REAL weak-signal work, and very challenging."

Bill goes on to say, "So how have I done?  Pretty good! Since last
January 1st, I've worked 30 states plus Canada and Mexico,
comprising a total of 94 grid squares, on 6-meter MS using the WSJT
digital modes."

He continues, "The problem is that there are not nearly enough hams
who are set up to use WSJT. Whether this is from lack of interest or
just lack of information, I don't know -- but it's really TONS OF
FUN!"

He continues with, "The place to go to find out more about meteor
scatter propagation on 6 and 2 meters is,
http://www.pingjockey.net/cgi-bin/pingtalk.  This is where "ping
jockeys" hang out, make skeds with each other to try to complete MS
QSOs, and generally discuss this aspect of the hobby. There are
links here to documents that describe how the MS protocols work. The
other vital place to go on the web is Joe Taylor's page,
http://physics.princeton.edu/pulsar/K1JT/, where his WSJT software
can be downloaded for free."

Thanks, Bill!  Very interesting.

Don't forget Straight Key Night, beginning 0000z on January 1,
running for 24 hours.  For details, check,
http://www.arrl.org/contests/rules/2008/skn.html.

Finally, on the AA1TJ web page,
http://mjrainey.googlepages.com/dasderelicht, check out this simple
project for converting a standard compact florescent lamp to an 80
meter transmitter.

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 December 18 through 24 were 0, 0, 0, 0, 0, 0,
and 0 with a mean of 0.  10.7 cm flux was 68.4, 69.2, 69.1, 68,
67.7, 68.6, and 69.4 with a mean of 68.6.  Estimated planetary A
indices were 1, 3, 2, 2, 4, 9 and 5 with a mean of 3.7.  Estimated
mid-latitude A indices were 0, 2, 2, 1, 3, 8 and 5 with a mean of 3.
NNNN
/EX


EXPLORE ARRL

Instragram     Facebook     Twitter     YouTube     LinkedIn