Topband: Inverted L by the sea

Herbert Schoenbohm
Wed, 02 Oct 2002 20:46:21 -0400


I had a similar problem when I worked for WIRA in Ft. Pierce, FL wherein 
a pier on the Inter Costal Waterway support their AM tower.  The base 
current would change significantly with the tidal fluctuation. An 
expanded copper mesh ground screen and some elevate radial anchored back 
to the sea wall did reduce the amount of fluctuation but never 
eliminated it.  After talking with some antenna people about the problem 
they came to the conclusion that as long as the salt water under the 
antenna provided a better ground system than the elevated one the whole 
thing would react like moving the plates on a variable capacitor.  You 
might want to try a true vertical without the inverted L configuration. 
 Even if the vertical is less than 90 degress it might not fluctuate as 
much as an inverted L does.

Good Luck,

Herb (ex-KV4FZ)