When I refer to a SR peak in my earlier post, I'm referring to an increase
in actual signal levels (with corresponding increase in S/N).
73. . . Dave, W0FLS
From: Nick Hall-Patch
Sent: Friday, January 12, 2018 11:23 AM
To: Petr Ourednik ; email@example.com
Subject: Re: Topband: Band Open - But No Sunrise Peak
Wasn't some of the apparent peaking of signals at sunrise due to
improved signal to noise levels as noise levels drop at sunrise?
20 years ago for many of us, noise levels did actually drop at
sunrise. For many DXers now, (man-made) noise levels stay the same
after sunrise, so, no apparent increase in signal strength (actually
increase in S/N ratio).
This is not to say that there was no "real" increase in signal
levels at sunrise 20 years ago, just that it was perhaps less
frequent than was thought at the time. If someone has recorded
signal strength levels from that period, I'd be happy to be proved wrong.
This morning, in western Canada, a medium-wave broadcaster,
HLAZ-1566kHz from South Korea was audible until after 1700UT, an
hour past local sunrise, with a reasonable sunrise
peak. Yesterday, there wasn't much of a sunrise peak, and local
noise conditions haven't changed that much over 24 hours.
Was any west coaster on 160m on those two mornings?
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