SB PROP @ ARL $ARLP035 ARLP035 Propagation de K7RA ZCZC AP36 QST de W1AW Propagation Forecast Bulletin 35 ARLP035 From Tad Cook, K7RA Seattle, WA August 31, 2012 To all radio amateurs SB PROP ARL ARLP035 ARLP035 Propagation de K7RA Although solar activity is quite low, we did see an increase in sunspot numbers and solar flux over the past week. Average daily sunspot numbers were up nearly 20 points, or about 36 percent, to 74.1. Average daily solar flux increased nearly 13 points to 108.7. There was also quite a remarkable increase on Thursday, August 30, when the sunspot number jumped 23 points from Wednesday's value to 118, and solar flux was up nearly 10 points in one day to 127.8. Both of these numbers will figure into next week's averages, as our reporting period is Thursday through Wednesday. One new sunspot region appeared on each of the three days, August 23-25, then three new regions appeared August 27, then one each on August 28-29, and three more on August 30. The latest forecast has activity over the next week a bit lower than the forecast a few weeks ago, but somewhat higher sunspot numbers than the prediction in the August 30 ARRL Letter. Predicted solar flux is 130 on August 31 through September 7, 115 on September 8, 110 on September 9-10, 105 on September 11-12, 100 on September 13-16, 95 on September 17-22, then 115 on September 23, 120 on September 24-25 and reaching a peak of 125 on September 26-28. Predicted planetary A index is 10 and 8 on August 31 through September 1, 5 on September 2-7, 8 on September 8-9, 5 on September 10-14, 12 on September 15-16, 8 on September 17-18, 5 on September 19, 8 on September 20-21, 10 on September 22, and 8 on September 23-25, followed by 5 on September 26 through October 4 and 8 on October 5-6. OK1HH predicts quiet to unsettled geomagnetic conditions on August 31, mostly quiet September 1-2, quiet to unsettled again on September 3-5, quiet on September 6-8, quiet to unsettled September 9, quiet to active September 10-13, quiet September 14-15, mostly quiet September 16, quiet to active September 17-18, quiet September 19, mostly quiet September 20, quiet September 21-22, and quiet to active September 23. We received a note from Ray Bass, W7YKN of Sparks, Nevada about how the HF bands don't seem as good as they were during past solar cycles. Ray writes, "Only find ten open a little and twenty real good once in a while and not like years past, or is my receiver broken?" Although cycle 24 is predicted to peak between February and July 2013, solar activity this year has been substantially below what it was toward the end of last year. There isn't enough sunspot activity to sustain 10 meters, although fall should provide an advantageous seasonal variation for most paths. Currently sunspot activity is stronger than it was exactly a year ago. 55 days covers two complete solar rotations, and the 55 days from early July through August 29 had a daily sunspot number average of 87.2. On the same days last year the average was 20 points lower, 67.2. We received reports of recent sporadic-e and tropo propagation on VHF. Jon Jones, N0JK in Kansas wrote, "A surprisingly good series of sporadic E openings on 6 meters August 24-26. The evening of August 24 many double hop Es contacts were made from W3, W4 to California. Earlier Central America was in to Colorado, Michigan and the Gulf Coast. From Kansas - worked on 6 meters August 24, WA7JTM DM33, WB7BBI DM93 (short Es at 825 km, high MUF), K8OY EM88, WB3BEL FM18 and N4OX EM60. This opening was 28 days (one solar rotation) after the big 2 meter Es opening July 24. Perhaps a solar influence?" Jon also wrote in a later message: "Had a strong tropo opening Monday morning August 27 from NE Kansas to IL, MN, NE, and WI. I worked W9EWZ EN52, KA0PQW EN33 and KQ0J EN11 around 1330 UTC on 144 MHz. My station was a FT-897 50 W and a 7-element M2 Yagi portable." Jon sent a picture of a radio sitting on a sidewalk, hooked to a Yagi about 5-6 feet high mounted to a post in the ground. K1KT, Ken Tata of Warwick, Rhode Island wrote on August 24, "Tropo has been quite good along the East Coast the last three nights. Last night I went portable to Narragansett, RI to operate 2 meters. When I arrived there was an onshore breeze. Despite that, using an 11-element Yagi and 50 watts, best DX for the evening was FM17 and FM16. Also heard the Cape Hatteras beacon, about 480 miles away. Everything I heard was coastal. Except for the beacon, most signals were in the S5 to S7 range with about 12 dB of QSB. Signal levels improved up til 11PM local time when I packed up and went home." Ken wrote later and said these three nights were followed by another three nights of good tropo activity. Ken continued, "Since this wasn't a contest, activity was rather light, but even relatively 'small' stations did well and had fun! We need more activity on VHF/UHF! There are lots of IC-706s, FT-100s, IC-746s, and other rigs with 6 meter and 2 meter capability. Relatively high gain 2 meter antennas are not all that big. You can build a WA5VJB 'Cheap Yagi' for literally a few bucks. You can carry an assembled 11-element Yagi or 8-element Quagi for 432 on the back seat of your car. Portable operation can be considerably easier and setup faster than for HF." Ken mentioned the WA5VJB Cheap Yagi. For more information, see http://www.fredspinner.com/W0FMS/CheapYagi/vjbcy.html, http://www.wa5vjb.com/yagi-pdf/cheapyagi.pdf and http://www.k8gu.com/?p=438. 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 at http://arrl.org/propagation-of-rf-signals. For an explanation of the numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere. An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation. Find more good information and tutorials on propagation at http://myplace.frontier.com/~k9la/. Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation. Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins. Sunspot numbers for August 23 through 29 were 49, 69, 70, 78, 85, 73, and 95, with a mean of 74.1. 10.7 cm flux was 96.7, 104.2, 105.9, 113.2, 111.5, 111.2, and 118.3, with a mean of 108.7. Estimated planetary A indices were 10, 9, 10, 11, 7, 4, and 4, with a mean of 7.9. Estimated mid- latitude A indices were 11, 9, 10, 10, 7, 3, and 5 with a mean of 7.9. NNNN /EX