SB PROP @ ARL $ARLP035 ARLP035 Propagation de K7RA ZCZC AP35 QST de W1AW Propagation Forecast Bulletin 35 ARLP035 From Tad Cook, K7RA Seattle, WA August 28, 2009 To all radio amateurs SB PROP ARL ARLP035 ARLP035 Propagation de K7RA Last week's Propagation Forecast Bulletin ARLP034 reported that the sporadic-E season was probably over, but then we heard from Mark Bell, K3MSB of Airville, Pennsylvania (FM19ut). He reports that nine days ago on August 19 he worked KG4NL in Guantanamo Bay (FK29) on 6 meter CW at 2208z. KG4NL was weak in Pennsylvania with significant QSB, where Mark was running 100 watts into a five element Yagi at 20 feet. Bill Rinker, NE9Z in Moran, Wyoming wrote in to ask how the Solar Flux Index is measured. Bill is in the Teton National Forest, about 20 miles south of Yellowstone National Park. The solar flux readings are done at an observatory in Penticton, British Columbia, three times per day. The one we use for the official solar flux is the noon reading. The other readings are done in the morning and afternoon. You can see all of those readings for the past few years at http://tinyurl.com/ks8tvn. The ones to pay attention to are the readings at 2000z (which are shown in the table as 200000 in the second column) and the observed flux values are in the fifth column. The sixth column shows adjusted flux values, which are corrected for variations in the distance from Earth to Sun. The adjusted values may be useful for measuring what the Sun is doing, but the observed flux gives an indicator of the relative amount of 2.8 GHz energy that is reaching Earth. 10.7 cm is the approximate wavelength at 2.8 GHz. The page at http://www.spaceweather.ca/sx-eng.php has more detailed information about the solar flux under "Information about the Programme." Mark Lunday, WD4ELG of Hillsborough, North Carolina notes that as the Summer season slowly wanes, static on the lower frequencies is subsiding. Mark recently worked VQ9LA on 80 meters CW with 100 watts and a modest vertical. Jeff Lackey, K8CQ of St. Simons Island, Georgia has written to us before with his observations on the number of zero sunspot days between cycles. This time he sent a graphic showing how this minimum is similar to the one prior to Cycle 19 (the big one) and earlier cycles, rather than more recent cycles after 19. Currently we have had 48 continuous days of zero sunspots. Jeff said if this continues for the next couple of days, it will be the only cycle minimum since 1855 with two greater than 50 day runs of zero spots. Back then it was the transition to Cycle 10. It is happening right now, and it happened in 2008 also. He notes, "There is still DX to be worked. You just have to be very patient. I heard the V73NF station on 40m CW earlier this week (Aug 24) about 1100 UTC but they didn't seem to be coming back to anyone in NA. So I'm not sure they were hearing very well. They finally went QRT and left a lot of us exasperated. This morning the KH2/K7BV operation was quite strong but the QRM for me was too much to be heard. They worked several NA stations from 1230 to 1300 UTC but I never could crack the pile up. I've got both DXCC entities before in previous operations; so I wasn't totally bummed out." Jeff works all his DX with a flagpole antenna and by loading up his rain gutter. Geophysical Institute Prague predicts quiet to unsettled conditions August 28, quiet August 29-30, quiet to unsettled August 31, September 1 quiet, quiet to unsettled September 2, and active conditions on September 3. NOAA and the U.S. Air Force predict planetary A index for August 28 through September 6 at 5, 7, 10, 7, 5, 12, 7, 5, 8 and 6. 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 August 20 through 26 were 0, 0, 0, 0, 0, 0, and 0 with a mean of 0. 10.7 cm flux was 67.6, 66.4, 66.6, 67.3, 67.6, 67.1, and 67.3 with a mean of 67.1. Estimated planetary A indices were 11, 8, 5, 5, 3, 3 and 4 with a mean of 5.6. Estimated mid-latitude A indices were 8, 6, 3, 3, 1, 2 and 4 with a mean of 3.9. NNNN /EX