Maybe this will help clarify it. . .

As Walt and Danny said, this is all about efficiency -- the fraction of
your applied power that gets used heating the ground. So the ground wave
and sky wave are reduced by the same fraction. Just look at those dB
values in the right hand column of Walt's summary, and they'll apply to
75 meter sky wave as well as to ground wave.

They won't be exact, of course, since they depend on both ground
characteristics (to quite a fair depth) and frequency. But they're as
good a set of working values as you'll find.

Roy Lewallen, W7EL

Dan Richardson k6mheatarrl wrote:
On Fri, 1 Jul 2005 17:12:44 -0400, "Fred W4JLE"
wrote:


Walt, while this would be wonderful information if I were broadcasting
during the day on 75 meters, how is it applicable to those of us who don't
care about groundwave?


I think you may have miss the point Fred... Its about antenna
efficiency.

Danny,
K6MHE