Tuesday 27 October 2020

Very early arrival from VK3, and other anomalies.

Another fairly disturbed geomagnetic day brought enhancements for the 14MHz band, as evidenced by the 5W WSPR signal from VK3QN overnight (this large array is beaming long path Europe.)

Signals from VK3QN came in until 23:40UT, and then vanished until 01:30UT, where a very broad peak developed over the coming hours.  This is in marked contrast to the quiet conditions curve, which is very much sharper and later.


VK3QN's very broad, early reception at MW1CFN 2020 October 26-27

For comparison, three days' worth of VK3QN reception from two weeks ago, showing that the peak signal on 27/10/2020 was reached when it would, under quiet conditions, be only just beginning to appear.

As the screengrab from DXAtlas shows, 01:30UT is not a time when we would expect any signal by long path:

Situation as VK3QN appeared at 01:30UT (DXAtlas, with permission.)

Here's the indicative SNR forecast for a 130 degree-beaming VK3 antenna at 01UT (via Proppy), which doesn't take real-time geomagnetic conditions (or a 12-element array!) into account:


Another anomaly was the onset of receiving PT2HFC at 8729km from just before 01UT (I checked he was transmitting before this, which he was) when Brazil would, under quiet conditions, be entirely absent from my receptions from very late evening onwards:

Anomalous reception of PT2HFC at 14MHz

Meanwhile, TF3HZ, who would also not normally appear overnight, showed an interesting variation in signal, notably around 01UT, coincident with a fairly sudden restoration of the field - something that is found frequently in these analyses.  Long horizontal lines are periods of non-reception:

Reception of TF3HZ at 14MHz.


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