"K7ITM" wrote in message
oups.com...
So Dave, have you built a NEC model of the antenna? Do you know that
the loading stub really has unequal currents on its two legs? Since
that current is fairly close to the element itself, is the net current
(the antenna current) on the stub in phase with or out of phase with
the element current? What about the efficiency reported by NEC--if you
use zero loss conductors versus the loss of the actual aluminum used in
the antenna?

no, i don't own nec, and don't know enough about it's methods or limitations
to trust just throwing together a model to play with on any free version i
could get. i have done enough modelling professionally with tools like
ansoft/maxwell (for quasi static e-fields), EMTP (for power line
transients), TFlash (for lightning transients on power lines), Simulink and
EASY5 (electro-mechanical control systems), and some other tools, that i
know that if you don't know your tool and it's limitations that any result
you generate is questionable. besides, i have enough other things to do
this summer putting up new antennas and using them... not enough time to
second guess every design out there, I made my choice and I'll take my
chances... but the 40m4LLDD i put up last year at 105' seemed to work well
over the winter, and much better than the 40-2cd it replaced.... (compared
over almost a year now against another 40-2cd that hasn't been moved)... so
now i'm replaceing the other 40-2cd with a second 40m4LLDD at 175'. if
nothing else it will look impressive, and thats worth 3db or more in the
operator's belief that they are loud.