Topband: Extreme skewing

[Greg - ZL3IX]

I thought the group might be interested in the following.

For the past 15 years during southern half summer, I have held 160 m 
skeds at my sunset with my UK friends (and other W Eu). The success rate 
has varied from year to year, but when a QSO is achieved, the signals 
almost always pass over the Caribbean. Directional Rx antennas are used 
at both ends of the path, so the signal arrival azimuth can be 
determined fairly readily. The GC path is actually over southern South 
America, so the predominant path is skewed by around 45° at both ends.

For the past two evenings the skewing was extreme. John G3XHZ and John 
G3PQA both reported my signals arriving from the NW, and all G signals 
were also arriving from the NW at my end. This includes G3OLB, who is 
currently using an omni Rx antenna, so can't determine the arrival 
direction at his end. The skewing at my end was so extreme, that I 
thought we had suddenly switched to short path, which would also be 
possible in theory, but has never happened before. Normal short path to 
ZL from the UK is NE, however, so that is not the answer in this case. 
It appears that signals from the UK were passing over OX, northern VE 
and then being bent around to appear from W of N in ZL. The trajectory 
over the middle part of the path is pure conjecture, though.

In the 15 years in which I have been taking part in these skeds, I have 
never previously experienced this phenomenon.

73, Greg, ZL3IX