ARRL

ARRL Propagation Bulletin ARLP048 (2005)

SB PROP @ ARL $ARLP048
ARLP048 Propagation de K7RA

ZCZC AP48
QST de W1AW  
Propagation Forecast Bulletin 48  ARLP048
From Tad Cook, K7RA
Seattle, WA  November 18, 2005
To all radio amateurs 

SB PROP ARL ARLP048
ARLP048 Propagation de K7RA

Just last week we saw no sunspots. Then on November 13 we saw
sunspot 822 peek around the eastern side of the visible solar disk.
By November 15 we could see that it is a big one. Today, November
18, the spot should be squarely facing earth. The daily sunspot
number rose from 26 on Monday, November 14, to 32, 58 and 62 on
November 17.

Daily solar flux is based on the 2.8 GHz energy received from the
sun at an observatory in Penticton, British Columbia, Canada at
local noon, which is 2000z. The observatory has a parabolic dish
antenna aimed at the sun, and they produce three readings per day at
1800, 2000 and 2200z, although the 2000z measurement is the only
number recorded as the official daily solar flux. This number is
related to the area and number of sunspots facing earth, but does
not track it precisely. But it is more objective than counting
sunspots and measuring their area, which is how the daily sunspot
number is derived, and it has the advantage of being able to take
readings on overcast days.

For the past two days, November 16 and 17, the three daily readings
were 93.2, 94, 96, 97.1, 100.5 and 103.2. The 94 and 100.5 readings
taken at local noon each day were the official solar flux numbers
for those days. You can see the trend is up. Currently as this is
written early Friday, November 18, the interplanetary magnetic field
is pointing south, which means the earth is vulnerable to any flares
from sunspot 822.

This weekend is ARRL SSB Sweepstakes Contest. Sunspot numbers and
solar flux are both expected to remain relatively high, with solar
flux remaining around 100 for the next week. Geomagnetic activity is
expected to remain low over the weekend, with the planetary A index
for November 18-21 at 5, 5, 7 and 12. Geophysical Institute Prague
predicts quiet conditions on November 24, quiet to unsettled
November 20, 22 and 23, and unsettled November 18, 19 and 21.

Tom Coates, N3IJ wrote to ask about getting the WWV geo-alert
messages via the internet. The alerts are transmitted at 18 minutes
after each hour, and you can also read the latest copy at
http://sec.noaa.gov/ftpdir/latest/wwv.txt. If you want it via
telephone, call 303-497-3235. The broadcasts are updated every three
hours, after 0000z, 0300z, 0600z, 0900z and so on.

Osten Magnusson, SM5DQC sent in the observation that the lower the
solar flux, the better 160 meters seems to be. On November 11 he
mentioned that "Around October 25 the 160 meter band was as good as
it can be, now it's down again as sunspots have increased. Maybe
it's not scientific, but this is my experience!"

We received several interesting and informative emails concerning 10
meters. 10 meters seems to be open over various paths quite often,
although with the solar activity lower many people are not showing
up and operating. Those that do operate sometimes observe
interesting propagation.

Joe Murray, K0VTY of Ithaca, Nebraska said he heard LU6GB working
NL7Z on 28.49 MHz at 2012z on November 6. When Joe worked LU6GB,
signals were S9 both ways for 30-40 minutes. Of course, it helps
that Joe runs a 7 element homebrew monoband Yagi that he built over
40 years ago. He had it az-el mounted in 1965 with stacked 11
element 2 meter Yagis for satellite work, back when only the 2 and
10 meter bands were used for OSCAR. On November 13 Joe wrote again
to say that from 1805-1820z that day he worked Brazil and Chile on
10 meters with solid signals.

Joe Living, W3GW/KH6 lives on Maui, and he listens to 10 meters
every Saturday. He hears many mainland U.S. stations that cannot
hear each other, and often copies beacon stations. On November 12 at
1900z he heard the K5AB beacon in Texas at S5. On September 5 he
worked George, KA9YCB in Southern Illinois. George was using a tiny
indoor magnetic loop antenna. On November 13 Joe worked K7LEK in
Nevada on 28.4 MHz, then KD6AXR in Fullerton, California broke in,
and of course he and K7LEK could not hear each other. Joe mentioned
that he would like to monitor 28.31 MHz every Saturday, SSB or CW,
for readers of this bulletin wishing to check the 10 meter path to
Maui.

Most interesting this week was an email from Martin McCormick,
WB5AGZ of Stillwater, Oklahoma. Martin was amazed on the morning of
November 14 at 0200 CST local time (0800z) to record the KQ2H
repeater system in New York on 29.62 MHz FM. The repeater faded out,
then began coming in again around 0530 local time with New York
drive time traffic, probably from its 2 meter link. By 0600 CST it
was full-quieting. He tuned around the rest of 10 meters and the 11
meter band, and heard no other activity, except the tail-end of an
FM signal briefly on 29.64 MHz. Note that all this activity was over
night, for most of the time dark at both ends of the path.

I contacted Alex Muzyka, KQ2H who said the 10 meter transmitter is
running 1300 watts, and the antenna is a vertical at 300 feet on a
tower in Wurtsboro, New York, about 1950 feet above mean sea level.

Carl Luetzelschwab, K9LA commented that this propagation could be
due to F2 region ionization from geomagnetic field activity. Martin
thought perhaps this was very early winter E-skip.

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 and an explanation
of the numbers used in this bulletin see the ARRL Technical
Information Service propagation page at,
http://www.arrl.org/tis/info/propagation.html. An archive of past
bulletins is found at, http://www.arrl.org/w1aw/prop/.

Sunspot numbers for November 10 through 16 were 0, 0, 11, 16, 26, 32
and 58 with a mean of 20.4. 10.7 cm flux was 77.9, 78.6, 83.1, 87.8,
92.4, 100, and 94, with a mean of 87.7. Estimated planetary A
indices were 2, 5, 10, 14, 10, 4 and 3 with a mean of 6.9. Estimated
mid-latitude A indices were 1, 3, 7, 12, 7, 5 and 1, with a mean of
5.1.
NNNN
/EX