On Fri, 22 Jul 2011 09:51:18 -0700, Jeff Liebermann
wrote:

if I should include the 0.67
velocity factor of the coax dielectric covering the center conductor.
Is it 19.2" or 12.9" for the driven element?

Hi Jeff,

Ah! The sleeve dipole re-emerges.

The exposed wire isn't much different from any other insulated wire
antenna. Air dominates the dielectric constant to the now remote
braid and the plastic ever so slightly shifts things. EZNEC includes
modeling insulated wire.

More's the issue of the dielectric coefficient of the braid pulled
back over the outer jacket of your coax. Coupling issues to the
insulated braid there too shift dynamics - and probably dominates the
DC characteristic.

I usually cut long, and slowly snip the exposed wire until SWR
improves. Choking the line would stabilize this.

73's
Richard Clark, KB7QHC