[600MRG] 2200m Jigsaw Puzzle

[James Hollander]

    2200 m receptionsof  10 watt WH2XND during September have  delivered thousands  of decodes  atstations  all across the  US  and into British Columbia  and even Japan! What dothey mean, what’s the  big picture?  I  have tried to review the  decodes  at most of the receiving stations in timestampsequence and make comparisons.  Pleaselet me know at mrsocion at aol.com  what you may have learned instead  or  in addition to my general comments.  73, JimH  W5EST
     2200 m carriesthunderstorm static much  more effectively  and longer distances than  does 630 m.So my comments focus on propagation variations  on  days when most  of  the US was clear  of thunderstorms.
     During about 90minutes before  local sunrise, most stations most days  are observing  asignificant steadily rising SNR that reaches a strong peak. SNR then  steadilydeclines from  that peak  after sunrise for  a few minutes to  an hour depending  on how close  the  receiving station  is to XND’s Arizona QTH.  WG2XXM in Oklahoma and W7IUV in Washingtonstate have had  at least  all morning  and/or all afternoon, continual full-sunlightreception with SNRs in  the -20s dB.  In the  case  of XND-XXM, suchpropagation may be  more the  rule than the  exception.
   Around sunset the XNDSNR  at most stations rose steadily for a bout  an hour after the  first decode andthen plateaued or gradually rose just a  few more dB for several more hours. However,many stations saw two  or three dips  in SNR each about  an hour long so  that  theSNR steadily decreased to  a  minimum and then steadily increased back to  the  nighttime plateau. While the timing  of these dips seems random, they  are  about 6dBdeep  and their fall/rise behavior  is plain.   
   Some stations  east of XND or  east of theMississippi saw  a  deep two hour XND SNR trough  from 08z-10z that included receptiongaps. Like  an “SNR tsunami” XND SNR declinedto undecodable levels that before sunrise could recover and  then rise to  single digits before rapidlyfading  out afterwards.   Stations in  the Pacific Northwest rarely  had thistype  of reception.  I look forward to your impressions. GL.