Owen Duffy wrote in
:

steveeh131047 wrote in
:
The application is no secret - the first paragraph in my linked page
explains it.

Steve,

Another thought comes to mind, and that is a pair of rectangular
conductors, preformed to the parabolic like shape and screwed togeter with
insulated fixings.

You could achieve the Zo you seek with say 20mm wide flat with manageable
spacing... however it would be a water trap to some extent (just like LP
feeds using twin booms).

Owen