Topband: Modeling the proverbial "vertical on a beach"

[Tom W8JI]

For receiving, an absence of noise sources in the path is all the difference 
in the world. As an example of this look at what N7JW and K7CA did from the 
Utah desert area. Utah desert is like the anti-saltwater, and they are 
located much further from Europe than the east coast with a worse polar area 
path, yet they had outstanding results. Saltwater has the same advantage, as 
do freshwater bodies, of a lack of noise sources in what might be a desired 
direction.

For efficiency (which only affects transmitting), the advantage is primarily 
concentrated at low angles and primarily affects vertically polarized 
systems. The question then becomes one of wave angle and polarization.

Then there is distance as a factor, and path loss related to the magnetic 
poles, which are factors.

A good station has a combination of everything going for it, but there is no 
magic and there certainly isn't any 10 dB or more involved just from being 
near saltwater. A few dB here and there from multiple factors are what make 
the difference. Move 25% or 50% closer, get rid of noise sources in the 
path, increase vertical antenna performance at low angles a few dB, and get 
away from going past the magnetic poles and it is a winner. It isn't from 
magic, and it isn't all from the presence of saltwater, and it is not 10-20 
dB by any stretch of the imagination.

73 Tom