Topband: Effect of current max not at base of vertical.

[Richard Fry]

Guy Olinger wrote:

>EZNEC's "fresh water" selection shows a conductivity of .001 (very
>unconductive). So it's talking about Great Lakes fresh water away from
>urban polution.

The conductivity chart for the continental U.S. published by the FCC shows a
conductivity of 8 mS/m for the Great Lakes.

Below is a link showing the groundwave coverage contours of WATZ in Alpena,
MI, which is located on the shore of Lake Huron in a land area of Michigan
with a conductivity of 8 mS/m.  These contours are calculated with respect
to the conductivity of the propagation paths, and do not show that the
conductivity of Lake Huron is anything approaching as poor as 0.001.

http://www.radio-locator.com/cgi-bin/pat?call=WATZ&service=AM&status=L&hours=U

R. Fry