Ward N0AX wrote:
... The electron gyrofrequency (I just *love* saying "gyrofrequency", don't you?) in the lower layers ... is much closer to 1.8 MHz and causes the wave coupling to change dramatically in ways that are not well understood. This changes with latitude and time of day (or night). ... etc
At least as important as understanding how 1.8 MHz skywaves interact with the ionosphere is understanding the space-wave fields that are actually _launched_ by a monopole at various elevation angles toward the ionosphere.
Those fields are not accurately described by NEC far-field elevation patterns, which show the fields/pattern at an ~infinite distance over a flat ground plane of ~infinite extent.
NEC calculations are accurate for those conditions, however those conditions do not exist in the real world.
R. Fry
_______________________________________________ Topband reflector - [email protected]
