SB PROP @ ARL $ARLP003<br />ARLP003 Propagation de K7RA<br /><br />ZCZC AP03<br />QST de W1AW <br />Propagation Forecast Bulletin 3 ARLP003<br />>From Tad Cook, K7RA<br />Seattle, WA January 20, 2006<br />To all radio amateurs <br /><br />SB PROP ARL ARLP003<br />ARLP003 Propagation de K7RA<br /><br />As we cruise into the low part of solar cycle 23, the sun has been<br />very quiet, save for some coronal holes providing solar wind<br />streams. This week average daily sunspot numbers were up nearly ten<br />points compared to last. The geomagnetic field has been mostly<br />quiet, although a little more active than the previous week.<br /><br />Over the next week expect solar flux to stay around 90, with<br />geomagnetic conditions quiet, except for some unsettled to active<br />conditions around January 23-24. Geophysical Institute Prague<br />expects quiet conditions January 21, quiet to unsettled January 20<br />and 22, unsettled January 25 and 26, unsettled to active January 23,<br />and active conditions (higher A and K index) on January 24.<br /><br />Rich DiDonna, NN3W of Virginia writes that, "While conditions on the<br />high bands may stink, conditions on the low bands have been<br />spectacular. 40 meters is opening to Europe as early as 2100z from<br />the East Coast with reliable openings to the Middle East, and long<br />path to Southeast Asia. 80 and 160 have also been amazing. So, while<br />Old Sol may be in "nap" phase, one should not assume that there is a<br />lack of DX to work!"<br /><br />Jon Jones, N0JK of Kansas echoes Rich's comments about the lower<br />frequencies in a January 14 email. He writes, "160 meter propagation<br />to Europe from the Midwest and western USA is picking up. For a low<br />band propagation beacon I listen to the 1.2 megawatt AM station from<br />Kvitsoy, Norway on 1314 kHz. Its signal has been very strong the<br />last couple of evenings. Great 160M conditions were noted by W8CAR<br />and others the same time to Europe."<br /><br />Jon also noted an extensive 6 meter E layer opening on January 13-14<br />in which W1, W2, W3 and W4 stations were coming in.<br /><br />Charles Lewis, S9SS of Sao Tome and Principe (an African island in<br />the Atlantic Ocean about 150 miles west of Libreville, Gabon) was<br />one of the stations reported in a recent bulletin by K7HP in Arizona<br />as worked on 10 meters. Charles writes, "The reason Hank worked me<br />that night is that I also use propagation beacons. On 10 meters, I<br />primarily depend on the W3VD beacon in Laurel, MD. That evening, as<br />I often do, I had the receiver tuned to the W3VD beacon while I<br />worked at the computer across the room. About 2110z I heard the<br />beacon rise dramatically out of the noise. I checked and found the<br />band was becoming live with 10 meters stations. I fired up my amp<br />and called CQ. In a period of about 40 minutes I worked about 40<br />stations. I would have worked many more, but it took a while of rag<br />chewing before I was discovered by the crowd."<br /><br />He continues, "These late 10 meters openings are not very unusual<br />for me in the 2015 to 2130z time frame. They more often start around<br />2030 to 2040z. They might last a few minutes or they might last a<br />couple of hours. Until early last year, they were nearly nightly.<br />Now they are a lot more scarce. There have been many times that I<br />heard W3VD with a good signal and could raise no one or perhaps had<br />a long rag chew with someone followed by no takers afterward."<br /><br />Charles goes on to say, "I also had a very good opening on 12/11,<br />the second day of the ARRL 10 Meters Contest that began about 2010z.<br />I worked about 115 contacts coast to coast in NA over a period of<br />about 50 minutes until it died. In that case also, I was working at<br />the computer and heard W3VD pop out of the noise. The band usually<br />dies about as suddenly as it comes to life."<br /><br />He continues, "I am only about 20 miles north of the Equator. There<br />is only about a 20 minute variation in sunset time over the year.<br />The sun is usually down well before 1800z, so these openings are<br />long after my sunset".<br /><br />Charles says that on 20 through 12 meters he uses the IARU beacon<br />system, and on 12 meters he often hears 4U1UN in NYC coming in<br />strong, while no one else seems to be on the band. He says 20 meters<br />is his best band for working the USA, and is the best way to<br />communicate with friends near his vacation home in Western North<br />Carolina.<br /><br />Charles has an interesting challenge operating from his QTH, and<br />that is from a huge Voice of America transmitter site that seems to<br />hover over his station in a photo he sent. Check out a similar image<br />on the web at,
http://groups.msn.com/s9ss.<br /><br />A couple of weeks ago Carl Luetzelschwab, K9LA had some comments<br />about SSNe, or Effective Sunspot Numbers, and the T-Index. He<br />continues with more comments below, through the end of this<br />bulletin.<br /><br />Carl begins, "In the January 6 Bulletin, I said the T Index and SSNe<br />were similar methods that give a better picture of what the<br />ionosphere is doing "now." Both represent an effective sunspot<br />number based on real-time sounding of the F2 region critical<br />frequency. Let's look at the basic difference between SSNe and the T<br />Index.<br /><br />"SSNe is calculated from a worldwide set of ionosondes at<br />geomagnetic latitudes lower than 50 degrees. The SSNe plot also<br />shows the RMS % difference between the foF2 values used to derive<br />SSNe and foF2 calculated from the model using that SSNe as input.<br />This parameter typically runs about 20% or so - if it exceeds 30%<br />this indicates that the global ionosphere is departing more from the<br />model expectation than usual. And if it exceeds 50%, buyer beware!<br /><br />"The T Index is calculated from 14 ionosondes in the Australian<br />sector. The regional maps (Australasia, Europe, and North America)<br />show the difference between the predicted monthly T Index (which is<br />in tabular format at
www.ips.gov.au/HF_Systems/6/4/1) and the<br />current observed hourly conditions in the desired region.<br /><br />"Which one is best to use? That's a tough call, but I'd personally<br />give the edge to SSNe for global predictions as it is based on<br />worldwide data.<br /><br />"To reiterate from the January 6 Bulletin, neither gives us a daily<br />model of the ionosphere. But both do allow you to assess whether the<br />current conditions are generally equal to, better than, or worse<br />than the median value from your propagation prediction program when<br />using the heavily averaged smoothed sunspot number (or smoothed<br />solar flux).<br /><br />"Thanks to Jim Secan of Northwest Research Associates in Tucson for<br />information on SSNe and for forwarding the T Index information from<br />Garth Patterson at IPS."<br /><br />If you would like to make a comment or have a tip for our readers,<br />email the author at, k7ra@arrl.net.<br /><br />For more information concerning radio propagation and an explanation<br />of the numbers used in this bulletin see the ARRL Technical<br />Information Service propagation page at,<br />
http://www.arrl.org/tis/info/propagation.html. An archive of past<br />propagation bulletins is found at,
http://www.arrl.org/w1aw/prop/.<br /><br />Sunspot numbers for January 12 through 18 were 12, 0, 0, 32, 42, 36<br />and 50 with a mean of 24.6. 10.7 cm flux was 76.5, 76.5, 77.4, 80.9,<br />83.8, 82.5, and 85.6, with a mean of 80.5. Estimated planetary A<br />indices were 3, 2, 3, 4, 14, 8 and 5 with a mean of 5.6. Estimated<br />mid-latitude A indices were 2, 4, 2, 4, 8, 10 and 9, with a mean of<br />5.6.<br />NNNN<br />/EX
