On Sun, 27 Jul 2008 23:04:02 +0100, Dave wrote:

As someone else said, this stuff can get very complex very quickly.

Hi Dave,

Your kick-off was already complex. A thick-wire can be monstrously
thick and not do much about the overall length at the principle
resonance:
http://home.comcast.net/~kb7qhc/ante.../Cage/cage.htm
It does have its advantages higher in frequency.

When we look at cage conicals, the flare angle of the conical shows
interesting relationships - not so much at resonance as for the
continuum of reactance and resistance. What I describe as optimal
bears upon an arbitrary 50 Ohm relationship, but others might mine
significance from the steeper skirts of the discone.
http://www.qsl.net/kb7qhc/antenna/Discone/discone.htm

73's
Richard Clark, KB7QHC