On Sun, 16 Oct 2005 18:28:36 GMT, Ed
wrote:
I plan on replacing this dipole with 450 ohm ladder line feed doublet

Hi Ed,

The answers to your questions are found in the quote above.

If those bands on the old antenna were already resonant, and they
matched, then you didn't need 450 Ohm ladder line.

If you are going to use 450 Ohm ladder line on a generic doublet, it
stands to reason you won't be resonant much anywhere (or you don't
count on it) and you anticipate tuning and use this line for low loss.

The only thing left to be said is about the lobe structure at any
particular frequency. Long, long antennas at high frequency develop
sharp lobes and nulls. That being said, it is more a matter of where
you are pointed and where you want to be heard. The solution to that
is to use a fan tail design for the higher bands' sake.

Using a doublet, ladder line, and a tuner is classic - it works fine.

73's
Richard Clark, KB7QHC