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

On Fri, 22 Jul 2011 11:35:09 -0700, Richard Clark
wrote:

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

Another solution I've tried is to put a choke on the line that I can
slide along its length (and later tape down). I then put a connecter
at the far (antenna) end of this line. I then put a bare/insulated
wire on a female connecter and mate the two. This preserves the line
from stripping and peeling back.

I cannot vouch how effective this is as a "Sleeve Dipole" in all the
standard characteristics. The Choke Z would have to be very, very
high to electrically snip the lower end to the right length to tune
it. Another choke a quarter wave away would be necessary. All
doable, certainly, but ad-hoc.

73's
Richard Clark, KB7QHC