"Ed_G" wrote in
. 192.196:


Bunk. The only reason the shields would not radiate would be if they
carried equal but opposite currents. That is most unlikely in this
case.



If both shields, ( ungrounded ) are tied together, and the two

At both ends?

This is the first mention of shields tied together, I certainly didn't
read that into Bruce's "with the shield left open on each end
".

center conductors are acting as a 'balanced' feedline, how can
current flow on the outsides of the shields, if the interior currents
of the two center conductors are always 180 out of phase?

The analysis in this case is different, but if I understand your
scenario, the outer surface of the two coaxes which are tied together at
both ends but connected to nothing else still carries the common mode
current. that exists on the two open wire conductors just prior to
entering the coax assembly. No, you cannot guarantee that those currents
are equal and opposite, ie that there is no common mode current, and the
common mode current will flow entirely on the outside surface of the
outer conductors of the coax assembly when connected as you now propose.

Bruce hasn't explained what his configuration is supposed to do, so we
are still guessing about that one.

There is no answer to this problem, because the problem is ill defined.
You have just added a new element in tying the shields together. Other
questions exist like what other connections exist between tx feed line,
ATU, ant feed line, mast, roofing / rain gutters, any other conductors.

Somethimes knowing how to describe a problem is knowing the answer to the
problem... or conversely, not knowning the answer is the result of not
knowing how to describe the problem.

Owen