This past evening's anomaly at 14MHZ was my single spot reception of AA7FV at 01:56UT at -28dB, the only station outside the US, Latin America and the Pacific to do so, other than TF4AH - an often-seen situation with these unusual spots (TF4X only heard AA7FV at 04:40UT, just before the early greyline period, so is not of interest, likely being a long path signal.)
14MHz reception of AA7FV, 00UT-06UT |
Kp rose to 6 around 00UT, and remained at Kp = 4 for several hours thereafter. Once again, the single spot of AA7FV came as the magnetic midnight line was positioned midway between receiver and transmitter, the supposed great circle path making a tangent with the inner edge of the auroral oval. The Icelandic stations gave three spots between 01:10 and 01:56UT, but nothing after that.
AA7FV uses a large, bidirectional rhombic antenna with one beam aimed at Europe, and the beamwidth is very narrow. So we can be fairly certain that this very transient single spot had a very localised propagation mechanism.
Proppy 14MHz indicative (and not very accurate, given the unusual antenna in use) signal strength prediction at 02UT from AA7FV. |
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