Midnight spot - from OA!

Happy New Year!

Operations returned to WSPR receive-only on 14MHZ yesterday afternoon.

An interesting pattern emerged under quiet geomagnetic conditions with late evening spots:

Image: Tromso Geophysical Laboratory

It's difficult to comment about the 9L station, because I think he's only been operating a short while and there is nobody else from the whole of Africa transmitting on a typical day.  So this may or may not be unusual.  It would be very nice if, somehow, we could have more WSPR stations across Africa.

The ZS spots as late as 21:18UT are certainly unusual - and the single spot from Lima, Peru (OA4/PA3GFE), at just under 10,000km, exceptionally so.  Only two other stations heard the OA4 signal and, fascinatingly, OE9GHV heard him at 10dB greater strength than I did.  At the time, Lima was in the early stages of the grey line.  I'm again wondering about the likely path.

All spots for OA4/PA3GFE (only ~1 hour of transmissions sent altogether)

Terminator at 23:54UT 31/12/2018.  Image: DX Atlas, with permission.

I am working on the idea that an omnidirectional signal from OA may travel to the north, where a reflection somewhere over North America then makes it across the Atlantic to Wales - a non-great circle path.  At my QTH, the twilit ionosphere at about F2 height (if it were visually detectable), is just setting on my western horizon.  This is a key advantage conferred by my elevated and highly mineralised ground - a radiation pattern for my delta loop that allows access to horizon-hugging angles. This path may be reasonable, because after the OA spot - and the setting of the twilit ionosphere - all spots from the west, from any location, cease.

Sadly, OA4/PA3GFE only seems to have transmitted during the 23rd hour UT, so our ability to reach conclusions is seriously diminished.