Over the years I have seen a few comments with respect to signal peaking
around local midnight. If you search on "midnight signal peaking" in the
topband archives, you should come up with four results. The one from DJ8WL
back in Nov 96 appears to be the only relevant one that I found.
I don't know if this is somewhat consistent or just coincidental with the
variability of the ionosphere. Regardless, any physical explanation likely
involves D region chemistry.
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