Topband: 160m Band opening phenomena

[Robert Parkes]

Band opening times.Roger G3YRO recent comments on band openings got me thinking about my experiences many years ago:
Sunrise and Sunset band path propagation enhancement has been well reported over many years to the point ITU  says it can be 6-10dBs.When operating from tropical latitudes I used to find propagation was sometimes better 2-3 hour before dawn rather than the conventional observation of enhancement that occurs at/near sunrise/sunset at higher latitudes.I mentioned on this in a post back in 1997 ( http://lists.contesting.com/archives//html/Topband/1999-11/msg00174.html ).
4X4NJ and A61AJ also commented that they had experienced much the same phenomena.
I often wondered if it was local midnight at the centre of the path, (MAM --Midnight At Midpath) -  my evidence is only circumstantial as it relied on me being awake, near a rig; and, if and when the path opened at all which only seemed to happen about 1 day in 5. ;-(
73sBobG3REP