SB PROP @ ARL $ARLP003   
   ARLP003 Propagation de K7RA   
      
   ZCZC AP03   
   QST de W1AW     
   Propagation Forecast Bulletin 3  ARLP003   
   From Tad Cook, K7RA   
   Seattle, WA  January 21, 2011   
   To all radio amateurs    
      
   SB PROP ARL ARLP003   
   ARLP003 Propagation de K7RA   
      
   Average daily sunspot numbers dropped from 50 on the reporting week   
   ending January 5, to 38 on January 6-12, and now 21.3 on January   
   13-19.  Average weekly solar flux over the same three periods   
   dropped from 89.5 to 83.8 to 80.4 over this past week.   
      
   The latest solar flux prediction shows a value of 82 for January   
   21-27 and 88 on January 28-30, followed by 87, 85, 85, 84 and 84 on   
   January 31 through February 4.  Geomagnetic predictions have the   
   planetary A index at 5 over the next couple of weeks, except for a   
   value of 7 on January 22 and February 2-4.   
      
   Geophysical Institute Prague expects quiet conditions on January 21,   
   quiet to unsettled January 22, and quiet January 23-27.   
      
   Carl Luetzelschwab, K9LA, has a propagation column in WorldRadio   
   Online for February 2011 titled "Using Antenna Height As An Aid to   
   Propagation."  Of course, the higher the better, right?  But Carl   
   calculates the propagation modes over a particular path at a   
   particular date and time, and shows how the antenna radiation   
   pattern at different elevations would affect the signal.   
      
   Download the latest issue at http://www.WorldRadiomagazine.com.   
      
   Carl used the propagation prediction program VOACAP, and this   
   program as well as W6ELprop and others use the monthly predicted   
   smoothed sunspot number.  The latest predicted smoothed numbers for   
   January, February and March 2011 are 39, 43 and 47.  They show it   
   increasing four points every month through July, then three points   
   from July to August, and two points per month after that, through   
   June of 2012, followed by one point per month increase through   
   October 2012, then one point every two months until a peak of 90 in   
   2013 during February through July.   
      
   You can download W6ELprop at http://www.qsl.net/w6elprop and see a   
   tutorial in PDF format by K9LA at   
   http://www.arrl.org/files/file/Technology/propagation/W6elprop.pdf.   
   K4LWS has another guide at   
   http://www.datasync.com/mdxa/w6elprop.html.   
      
   Information on VOACAP is at http://www.voacap.com, and there is a   
   fascinating online version at http://www.voacap.com/prediction.html   
   in which you can calculate MUF from any point to any other point.   
      
   At http://www.voacap.com/coverage.html you set the time, month and   
   year, and it generates a coverage map with your station at the   
   center.  Color coding on the map shows the percentage reliability.   
   For location, they have many prefixes selectable in a drop-down   
   menu, or 59 locations in the United States, and 16 across Canada.   
      
   As an alternative, you can enter a four or six character grid   
   square.  You can find six character grid squares by call sign online   
   at http://www.qrz.com after you create a free account and log in.   
   Then another drop down gives you a wide variety of antenna heights   
   for vertical, dipole, and 3, 5 and 8 element Yagi antennas as well   
   as a theoretical isotropic radiator.   
      
   Any of nine HF bands, 80 through 10 meters, are selectable in   
   another drop down.  The sunspot number used is the International   
   Sunspot Number, which is lower than the NOAA Boulder number reported   
   in this bulletin. For each month they use the predicted smoothed   
   sunspot number for that month.   
      
   This tool is fun to play with!  One cool trick is to open the page   
   in two web browsers, set up parameters (for example) to have   
   everything equal except the year, then use Alt-Tab (if you are using   
   Windows) to take you back and forth between the two maps, easily   
   seeing the differences.  Or you could do the same thing with a page   
   open in each of multiple tabs in a single browser.  I actually found   
   this easier than doing the Alt-Tab selection.   
      
   So for instance, I set up five tabs in my browser, one for each   
   month, January through May 2011, and used 10 watts on 10 meters into   
   a dipole at 10 meters high at 2100 UTC.  It is fun to click through   
   each tab and see how my 10 meter coverage would change over the end   
   of this winter and through spring.   
      
   Strangely, they have separate pages for the 11 meter band for each   
   type, point-to-point, and area coverage.  I suppose there are still   
   operators on the Citizens Band who might want this, and for the   
   extreme (and illegal) CBer, you can actually select up to 1500   
   watts, and an 8 element Yagi at 198 feet!  Doing this for March,   
   2013 sets up an impressive coverage map.  I can hear the howl of   
   heterodynes now.   
      
   Scott Bidstrup, TI3/W7RI sent in an article about creation of a   
   three dimensional model of the ionosphere that helps explain F layer   
   anomalies in equatorial regions after sunset.  Read it at online at   
   http://www.sciencedaily.com/releases/2011/01/110118113138.htm.   
      
   Patrick Dyer, WA5IYX of San Antonio, Texas (EL09ql) wrote last week:   
   "Several 6-meter ZL/VK-US events occurred since around Christmas,   
   mostly involving just K6QXY or N5JEH (NM). (Check the   
   lookback/search features on http://www.vhfdx.info/spots,   
   http://www.dxsummit.fi, http://dxworld.com/tvfmlog.html or   
   http://dxworld.com/50prop.html using the ZL/VK calls noted).  IA and   
   IL got into the Jan 10-11 event.   
      
   "The best guess, as this is near the Es peak in each hemisphere for   
   the Winter and Summer seasons, is Es-Es-F2F2-Es-Es (add another -Es   
   for the W0/W9 path).  F2F2 is the chordal hop over the geomagnetic   
   equator where the high ionization levels and effective tilts permit   
   very low angles of incidence (thus giving much higher MUFs than one   
   would expect from a "flat" layer). As most of the Es hops involved   
   are over water there is generally no evidence/warning of any   
   intermediate signals from along that path.   
      
   "The Jan 10-11 event, with its concentrated US hotspot footprint in   
   AZ, shows this very well as W0/W9 had Es linking them to/thru AZ.   
   Even during the Cycle 21-23 peak years 6m VK/ZL paths that far to   
   the US N.E. were rare vs. the numerous events to W6, south W7, W5,   
   and south W4."   
      
   Peter Laws, N5UWY of Norman, Oklahoma had a response to W1YO's   
   comment in last week's bulletin that "I have been through five solar   
   cycles and this one is not normal."   
      
   Peter writes: "With all due respect to W1YO, a sample size of five   
   is hardly enough to make a judgment about what is normal.  This   
   cycle may be different from the previous four or five, but we have   
   little evidence to determine if any of them is normal!"   
      
   "In all, we only have good data on the last 24 or so cycles and   
   less-accurate data for few more cycles before that."   
      
   "But our nearest star is about 4.5 BILLION years old.  That's over   
   400 MILLION solar cycles!"   
      
   True enough, but "normal" expresses what you are accustomed to, as   
   well as what expectations are. I think many of us wish that Cycle 19   
   was normal, as in, not unusual and that Cycle 24 was normal as well.   
      
   Speaking of what is normal and what is not, occasionally you can   
   read something in the press quoting someone who seems to be getting   
   it terribly wrong regarding solar activity. There was a "long range   
   weather forecaster" quoted this week in the Australian press who   
   says he uses sunspot activity to make his predictions.  He was   
   quoted as saying, "There is a huge amount of solar activity and   
   solar flares at the moment." Don't believe it? Read it at   
   http://snipurl.com/1w52z9.   
      
   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://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://mysite.ncnetwork.net/k9la/index.html.   
      
   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 January 13 through 19 were 14, 11, 11, 15, 36,   
   34, and 28, with a mean of 21.3. 10.7 cm flux was 79.5, 79.3, 80.2,   
   80.3, 81.8, 81 and 80.8 with a mean of 80.4. Estimated planetary A   
   indices were 6, 7, 5, 3, 4, 3 and 6 with a mean of 4.9. Estimated   
   mid-latitude A indices were 4, 6, 2, 3, 4, 3 and 5 with a mean of   
   3.9.   
   NNNN   
   /EX   
      
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   Gentlemens' agreements ratified by IARU regions 1 and 2 have   
   designated a global "center of activity" frequency  in  each   
   of  the  international  hf  bands.  THese are similar to the   
   concept for weak signal calling and other center of activity   
   frequencies.  Three of these have been ratified worldwide.   
      
   THese  center of activity frequencies are where stations can   
   go to render or obtain emergency assistance.   
      
   WHen casually operating or  contesting  on  hf  please  make   
   yourself  aware  of  these  frequencies,  and give them some   
   space. Remember that often stations with emergency needs are   
   not  those  utilizing  high  gain antennas and maximum legal   
   power.   
      
   TO find out more, visit 14300.net or IARU web resources.   
      
      
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