Topband: MF Anti-Podal Propagation Enhancement

Tue Mar 30 00:06:06 EST 2004

Chuck Hutton Said:
I - and a lot of DX'ers who specialize in international MW DX - would disagree with this. There are many examples of incredible antipodal receptions, with recent examples being the 300 kw 1557 Taiwan station received with some regularity in Brazil.

Thomas Giella KN4LF Says:
I've been a medium frequency AM broadcast band DXer since 1965. True unskewed antipodal propagation enhancement can only occur at frequencies that can propagate in daylight. At any given moment many of the propagation paths that are involved in antipodal propagation enhancement at medium frequencies are shut down by daylight D layer absorption, period!

Most of the propagation enhancement that we may mistake for antipodal focusing is actually via the E Valley/F Layer ducting mechanism.

73 & GUD DX,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX

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