On Feb 26, 10:23 pm, Owen Duffy wrote:
That doesn't preclude
current flowing on the outside of the line which seems to be your issue.
I won't confuse you with examples of where the outside of the line is
intended to carry current and at the same time the VSWR is low, but it is
possible and sometimes desired.

Yep, SWR and feedline decoupling are pretty much totally unrelated.
It's possible to have a great match, and horrible decoupling from the
line.
And visa versa.. Or versa versa, or visa visa..

JS ruminated
I DID find that the coax wanted to couple into the antenna and become
part of it (the sleeve itself was NOT a sufficient de-coupling device.)

It's not a decoupling device at all really. It's the lower half of the
antenna. A sleeve
half wave needs additional sleeves for decoupling. There are quite a
few
commercial variations that can be looked at. Many were built as heavy
duty VHF public service type antennas. The extra decoupling sleeves
can
be applied to the usual ground planes also. For VHF, etc, I usually
prefer using
sleeves, cones, radials, etc vs the usual rf choke or beads.
MK