SB PROP @ ARL $ARLP021   
   ARLP021 Propagation de K7RA   
      
   ZCZC AP21   
   QST de W1AW     
   Propagation Forecast Bulletin 21  ARLP021   
   From Tad Cook, K7RA   
   Seattle, WA  May 25, 2012   
   To all radio amateurs    
      
   SB PROP ARL ARLP021   
   ARLP021 Propagation de K7RA   
      
   Average daily sunspot numbers declined seven points over the past   
   week to 110.3.  Average daily solar flux dropped 3.3 points to 131.   
       
   Unsettled geomagnetic conditions over the past few days most likely   
   resulted from an interplanetary shock wave originating from a solar   
   flare on May 20.  Predicted planetary A index is 8, 5, and 8 on May   
   25-27, then 5 on May 28 to June 4, then 8, 12, 15, 10 and 8 on June   
   5-9, then 5 on June 10-11, 8 on June 12-13, 5 on June 14-16, then 8,   
   15, 10 and 8 on June 17-20, and 5 on June 21-25.   
       
   Predicted solar flux is 115 on May 25, 110 on May 26 through June 1,   
   125 on June 2-3, 130 on June 4, 135 on June 5-9, 130 on June 10, 125   
   on June 11-12, and 120 on June 13-15.  Six new sunspot groups arose   
   since May 15, one each on May 15, 18, 20, 22, 23 and 24.  Until June   
   4, predicted solar flux values are below the average for the past   
   week, 127.7.   
       
   We are again receiving geomagnetic forecasts from the Czech   
   Republic, this from Frantisek K. Janda, OK1HH of Ondrejov, from the   
   Czech Propagation Interest Group.  He predicts quiet to unsettled   
   conditions on May 25-26, quiet on May 27-28, mostly quiet May 29,   
   quiet to active May 30, quiet May 31 to June 1, mostly quiet on June   
   2, quiet to unsettled June 3, quiet to active June 4, active on June   
   5, quiet to active June 6, active on June 7, quiet to active June 8,   
   quiet to unsettled June 9, quiet June 10-11, quiet to active June   
   12, mostly quiet June 13, and quiet to unsettled on June 14-15.   
   OK1HH says that on May 30-31 and again on June 5 there is a high   
   probability of changes in the solar wind, which may cause changes in   
   the magnetosphere and ionosphere.   
       
   Bill Lauterbach, WA8MEA of Hanover, Michigan had a question about   
   MUF (Maximum Usable Frequency) and LUF (Lowest Usable Frequency).   
   He says the LUF seems to have changed so that it is sometimes close   
   to the MUF in the current cycle.  He wonders if LUF should be lower   
   when MUF is higher.   
       
   We passed this on to Carl Luetzelschwab, K9LA.  Carl commented, "The   
   MUF is determined by the amount of ionization - most of the time   
   it's the amount of ionization in the F2 region that sets the MUF.   
   And you can't do anything to your station to change the MUF."   
       
   "The LUF is essentially determined by absorption in the D region.   
   You can lower the LUF on a given path by increasing transmit power   
   or increasing your antenna gain or somehow reducing your man-made   
   noise.  In essence your LUF is the frequency at which the received   
   signal is at your noise level."   
       
   "Since a higher MUF means more ionization, it seems to me that   
   generally there would be more absorption, too, which would increase   
   the LUF."   
       
   Thanks, Carl!   
       
   Another Carl, N5XE, Carl Hickman of Sulphur, Oklahoma wrote "On   
   Thursday evening (0330 UTC Friday, May 25, 2012), I called CQ on 15   
   meters.  TA2KN answered my call with a 599 plus signal.  He was so   
   strong, I was hearing an echo on his signal (both short and long   
   paths), which made copy somewhat tough.  Both paths were strong --   
   he was LOUD!  I had to use my attenuator to lessen the effects of   
   his long path signals."   
       
   "Less than 10 minutes later, I worked N5RB on the same band (short   
   skip for me).  After 33 plus years as a ham, I am still amazed at   
   propagation conditions that crop up from time to time.  It's always   
   fun to participate in rare openings on the bands."   
       
   Thanks, Carl.  TA2KN is at a scout camp in Turkey, where they have   
   quite a nice antenna system.  Carl worked them at what is probably   
   the best time of the day on 15 meters over that path at this time of   
   year.  I see that the short skip distance that Carl mentioned   
   between N5RB (Ecru, Mississippi) and N5XE in Oklahoma is 452 miles.   
   I calculated that by looking up their licensed addresses on a map,   
   then using the latitude and longitude for each station to calculate   
   distance on W6ELprop.  Carl heard the station in Turkey on both long   
   and short paths, and those distances are 6,194 miles and 18,680   
   miles.  This was calculated using the location for the scout camp   
   shown on http://aprs.fi/info/a/TA2KN, which is 41.07 degrees north   
   latitude, 29.117 degrees east longitude.   
       
   Don Kalinowski, NJ2E of Cary, North Carolina alerted us to the   
   National Air and Space Lecture Series, and one about the Solar   
   Dynamics Observatory.  See it at   
   http://airandspace.si.edu/events/eventDetail.cfm?eventID=2768 and   
   click on the View Archived Recording link to watch the 71 minute   
   video, titled "The Solar Dynamics Observatory:  The Sun Up Close and   
   Personal."   
       
   Jon Jones, N0JK of Lawrence, Kansas fills us in on 6 meter activity   
   with a station in Argentina.  He wrote, "Some interesting   
   propagation on 6 Meters the afternoon of May 19."   
       
   "K0HA EN10 NE reported working LU1DMA around 2010 UTC.  I went out   
   portable with a 2- element Yagi."   
       
   "Initially I heard no signals other than the WB0RMO/b EN10 on   
   groundwave."   
       
   "Then at 2105 UTC, LU8YD appeared on 50.110 on an otherwise dead   
   band.  Weak, then built up to a reasonable signal."   
       
   "Called him, and he replied.  Gave me a '5x5' and copied EM28 fine.   
   His grid is FF51 and logged at 2108 UTC.  I see Alex was spotted by   
   K2ZD and a W3."   
       
   "This was probably an 'Es link' to afternoon TEP.  There were single   
   hop Es before to Florida and afterwards to W3, W4 and W7."   
       
   "First LU on 6 Meters in solar cycle 24 for me."   
       
   Thank you, Jon.   
       
   Jeff Hartley, N8II of Shepherdstown, West Virginia wrote on May 19,   
   "I haven't been on the air much, but did manage to work the 7O6T   
   guys on 40 thru 15 meters, one QRP QSO near the end on 15 phone.   
   Signals were loud on 20 thru 15 most of the time in our evening.   
   The big operation stimulated quite a round of how to work a rare one   
   with big pile ups on the PVRC reflector.  Some DXers are obviously   
   masters of the art.  One tip I find very useful in spotting the   
   listening frequency on CW is to listen with a wide filter (over 2   
   kHz); it makes finding the DX station caller much easier.  Then try   
   to figure out which way they are tuning and follow along a bit   
   higher or lower depending on what direction they are tuning."   
       
   "I operated in the CQ M contest May 12th just about 2-1/2 hours and   
   found 20 meters to be very poor from 1200-1300Z, but 15 sounded good   
   with one of the loudest signals from UP0L.  On 20 in the evening   
   around 0200Z, there were loud signals from western Europe across to   
   Zone 18, but virtually all except EA's had heavy flutter, making   
   copying at high speeds difficult."   
       
   "It is Dayton weekend, so the bands should be abnormally quiet.  I   
   will try and make some noise."   
       
   This weekend is the CQ World Wide WPX Contest.  Conditions should be   
   fair, with unsettled but not terribly active geomagnetic conditions,   
   and low sunspot activity.   
       
   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 May 17 through 23 were 114, 118, 110, 124, 120,   
   95, and 91, with a mean of 110.3.  10.7 cm flux was 136.3, 132.2,   
   130.9, 130.8, 125.1, 121.3 and 117.2, with a mean of 127.7.   
   Estimated planetary A indices were 6, 8, 5, 13, 7, 16, and 18, with   
   a mean of 10.4.  Estimated mid-latitude A indices were 5, 8, 5, 12,   
   7, 15, and 13, with a mean of 9.3.   
   NNNN   
   /EX   
      
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   Providing   emergency   communications  assistance  to  your   
   neighbors and community isn't just a good thing to do,  it's   
   the first and foremost activity recognized in the U.s. rules   
   governing amateur radio in 47 CFR section 97.1. IF you enjoy   
   amateur  radio  remember  that  this  is  an  obligation you   
   tacitly agreed to when you acquired your license.   
      
      
      
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