W1NEJ Anomaly - 25/26/2018

Another interesting anomalous WSPR spot came through on 14MHz overnight, this time from Eric, W1NEJ in Boca Raton, Florida.  Receiver in use was the SDRPlay RSP1a.

Eric was running what is, for WSPR, a high output of 10W (40dBm), apparently into a straightforward dipole hung between palm trees.  Eric's site is very near the Atlantic coast, so is obviously a good place for radio.

This is the series of spots from Eric.  Notice the strong, -6dB and -9dB signals at 01:40 and 01:50UT, respectively, and the rapid weakening of the signal to undetectability over the next 40-odd minutes.  Notice also how W1NEJ is the only signal heard here in the 6-hour period between 23:12UT and 05:08UT:

This is how the spots look, plotted against time (blue vertical lines are midday and midnight UT)

Locally in Wales, the Norwegian line magnetometer plots again show the field was returning to quieter conditions between 01 and 02UT, after a fairly minor disturbance at high latitudes (essentially, the daily 'ripple' of the night-time auroral oval's passage):

Looking at the graphic of the planet at 01:40UT, it's again evident that the propagation path was likely to involve ionised patches in the F2 region to cover the 3663 nautical mile distance at this time of day.  Multiple hops off geomagnetically-induced E patches are also possible,but perhaps less likely.  Another option is some non-great circle path, assisted by the geomagnetic field. 

Terminator at 01:40UT, 25/12/2018.  Image: DX Atlas, with permission.

Also interesting to note that, after 01:28UT, I was the only station outside the US hearing W1NEJ.  I have seen this with other stations, as previously noted.