One Thousand Kilometres

The overnight WSPR report is a little different this morning.

There were no anomalous DX WSPR spots at 14MHz, the last DX station heard being 5W from K6MCS (8130km), at the unusually late time of 22:44UT.  That spot may be explained by a limited patch of ionisation at mid-Atlantic longitudes, as the OVATION model suggests:

The field was fairly quiet, at Kp ~2, though the auroral oval disturbance around magnetic midnight was fairly pronounced.  The Z component underwent a northerly deviation at very high latitudes, but a small southerly deviation at sub-Arctic latitudes:

Image: Tromso Geophysical Laboratory

The peculiarity with this overnight period was the incredible consistency of the distance - just over 1000km - from which almost all WSPR stations were heard, as this plot, first with a logarithmic scale (broadly representative of global DX distances), and then a linear scale (with purple mean line) shows:

Clearly, the spread of distances is very narrow.  The mean is 1046km, the mode is 1087km, and the median also 1087km, with a maximum distance of 1349km, and a minimum of 329km.  As the log plot demonstrates, considering the global possibilities, signals were arriving only from one, short distance, which I guess is broadly a single hop distance.  I suspect this is also explained by the ionisation patches that occurred equatorward of the auroral oval.

I'm quite happy to have gathered all that data, as yesterday was quite windy, with sustained winds of 60km/h, and frequent gusts of 100km/h.  The cable tie that attached the pole to the windward rope stay on my delta had broken away just as I left for the day out.  With the wind load being very heavy on the pole, making it impossible to retract the fibreglass sections, there was nothing to do except use a stay not bearing any load and reposition it into wind.  That kept the antenna going until this morning, when a full repair was completed by 08:00!