Since the VF is 66% (or whatever the coax you use is) what
good (?)
effect would tophats have at the end of each section in an
effort
to make them resonant?

Just a thought.
Murray

Dave VanHorn wrote:

If you ever have the opportunity to disassemble an old Prodelin, or
Phelps-Dodge antenna, which is the commercial implementation of this
design,
you will find it very different from any of the ham construction
articles.
This design has many interdependent variables, and due to many
disappointments, the ham interest had waned by the time a real, correct
analysis was published.

As far as I know, the original disclosure of this design appeared in the
Proceedings of the IRE just after WW2, and is likely the closest to
correct.
But, for the life of me, I can't remember the inventor's name.

all that i've seen on the net just says that the vf affects the segment
lengths.
of course the radiating segments are significantly shorter than free space
half wavelengths, depending on velocity factor.

it seems the the ideal coax for this would have a very high vf, but i may be
missing something.

i can't see how it works so well, when the radiating elements are only 66pct
of what they should be.
Murray Kelly vk4aok