Hello Alan,
I recollect over long periods the best times at 136kHz were either just
after sunset, or
just before dawn<<<
Talking about "just after sunset, or just before dawn" is not very precise
as e.g. the time of the pre-dawn enhancement depends largely of the
season. Looking at e.g.
http://www.fourmilab.ch/cgi-bin/uncgi/Earth/action?opt=-p
it is apparent that for our latitude the dawn period is much longer now
than it is at the spring or autumn equinox when the grey line is marching
vertical from east to west.
At the moment the pre-dawn enhancement of reception of Canadian NDB's can
be about one hour and a half before actual sun-rise, whilst in winter it
can be about 15 minutes!
73,
Roelof Bakker, pa0rdt
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