Topband: Monopole Elev Pattern w.r.t. Earth Conductivity

Richard Fry rfry at adams.net
Wed Oct 24 19:33:27 EDT 2012


>The tall vertical tower was definitely worse compared to shorter verticals,
>and had almost no short skip signal around Georgia. I had isolation chokes
>for lights and a base insulator, but that 300+ foot tower was so poor I
>never used it as a vertical.

Not sure what frequency this comment applies to.  But a 300-ft tower would
be about 197 degrees in physical height on 160m, and its elevation pattern
would be close to the pattern for the 195-degree monopole shown in the plots
linked below.

The short skip being sought might better have been provided by a shorter
monopole, but a longer monopole (up to 5/8WL) would provide better
groundwave fields and low-angle fields, even with the ~poor earth 
conductivities
in some parts of Georgia.

http://i62.photobucket.com/albums/h85/rfry-100/MWElPatComparison.jpg

R. Fry 



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