If the "tophat" effectively isolates the section of tower or what have you
above it, then those folks matching towers with stacked beams are surely
loosing quite a bit of effective structure.
I have several 200-foot towers with lots of HF stacks. I asked that question
about a year ago when I was considering using them as verticals. Almost
unanimously, the replies were that it would not be an effective way to go. The
general consensus was that the first big antenna the tower saw, "would be the
end of the line" as far as loading went.
Alternative methods for using stacked towers were suggested at that time and
can be found in the archives.
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