"Steve N." writes:

OOPS! Jon,
IF it is "end-fed" is isn't a "di-pole". It is just a half wave. I
guess it is technically a monopole.

Sort of, sort of. The feed point is actually in the middle of the half
wave. Traditionally, it's called coaxial sleeve antenna. Except
originally, the sleeve was outside the coax braid. In this variation,
due to LA1IC Rolf Brevig, the sleeve is the outside of the coax, and
the end of the sleeve is a choke. He's written about it in English in
CQ, 1999, Aug pg 22. The version in Norwegian is on the web at
http://www.la2t.org/teknikk/vertikal2m.html.

I found an article from Microwave Journal about a very similar
concept: http://www.ansoft.com/news/articles/04.05_MWJ.pdf. They use
different kinds of choke, since they're at much higher
frequencies. They report performance very similar to a dipole.

73 de LA4RT Jon