2014-05-31

Fun with Sporadic-E (RU 6/14)

Map with 50 MHz QSOs-QSLs for the 2014 Es season (updated 2014-07-28)

The June 2014 issue of Radio User contains a Sporadic-E feature article by Keith Hamer and Garry Smith. It deals more with Es long distance TV reception than with 50 MHz amateur radio activity, but contains a few interesting ideas and observations:
  • It seems that there is a positive correlation between Es openings and low-pressure weather systems and thundery weather. While there is less chance for an Es opening during fair weather (anticyclonic conditions), which favors tropospheric propagation.
  • The authors believe that long distance Es propagation, usually attributed to multi-hop Es, is actually caused by signal paths close to the hotizon, which arrive to the Es layer at a very shallow angle.
  • When the opening extends to higher frequencies, propagation on the higher frequencies is better than on 50 MHz, which tends to be "turbulent".
The connection between stormy weather and Es was first discovered by hams in 1938. On June 5, 1938 a great opening on 56 MHz appeared over eastern USA , after heavy thunderstorms in many locations. The report is in QST, August 1938. A further analysis of the event by W1JFO was published in the next issue of QST, September 1938.

 

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