SB PROP @ ARL $ARLP039<br />ARLP039 Propagation de K7RA<br /><br />ZCZC AP39<br />QST de W1AW <br />Propagation Forecast Bulletin 39 ARLP039<br />From Tad Cook, K7RA<br />Seattle, WA September 24, 2004<br />To all radio amateurs <br /><br />SB PROP ARL ARLP039<br />ARLP039 Propagation de K7RA<br /><br />Fall is here--time for better HF conditions. But this week sunspot<br />and solar flux values are down. We went from a daily average sunspot<br />number of 77.6 for the week of September 9-15, to 52 during the week<br />of September 16-22. Average daily solar flux also dropped from 119.1<br />to 101.1 over the same two weeks. Solar flux is expected to remain<br />around 90 for September 24-28, and then rise to 100 by October 1.<br />Geomagnetic activity should remain low over the same period, with<br />planetary A indices in the single digits until October 4, when we<br />may see a rise in activity due to returning solar wind.<br /><br />More mail is coming in regarding 10-meters. At the peak of the<br />cycle, 10-meters sees plenty of activity, but now that conditions<br />are not as good on a daily basis, the band can be open but nobody<br />knows it unless they call CQ and someone answers, or they tune in<br />the beacon stations.<br /><br />Donald Anderson, WK6Q of Paradise California wrote about a 10-meter<br />opening last Friday and Saturday, September 17-18. Paradise is in<br />Northern California, north of Oroville and east of Chico. At 2355z<br />on Friday, he worked KB3KTR in Pennsylvania with a 5-7. Then a few<br />minutes later at 0005z he worked KB4TWJ in Georgia with 5-9 signals,<br />and the next day (local time) at 1950-1956z he worked LW1DDC in<br />Argentina with S9 signals followed by CE2WJP in Chile running only<br />five watts. Throughout the day he worked a number of stations around<br />the U.S. and in Latin America, followed by Japan. It was a great<br />opening.<br /><br />Listen to those beacons. If you don't hear activity on the band but<br />you hear beacons from some direction that sounds interesting, put<br />out a CQ. There might be others tuning 10-meters but changing bands<br />or turning off the radio if they don't hear anything. Bo Anderson,<br />OZ4B who is west of Copenhagen Denmark suggests this for 12 and<br />10-meters. He also knows the bands are open at times when nobody<br />seems to be on.<br /><br />If you would like to comment or have a tip, email the author at,<br />k7ra@arrl.net.<br /><br />For more information concerning propagation and an explanation of<br />the numbers used in this bulletin see the ARRL Technical Information<br />Service propagation page at,<br />http://www.arrl.org/tis/info/propagation.html.<br /><br />Sunspot numbers for September 16 through 22 were 80, 76, 50, 42, 59,<br />33 and 24 with a mean of 52. 10.7 cm flux was 108.3, 104.5, 102.7,<br />105.2, 100.5, 94.9 and 91.4, with a mean of 101.1. Estimated<br />planetary A indices were 17, 20, 16, 5, 13, 9 and 16, with a mean of<br />13.7. Estimated mid-latitude A indices were 14, 15, 16, 4, 8, 6 and<br />12, with a mean of 10.7.<br />NNNN<br />/EX