lu6etj wrote:

No, no :) both wires are introduced in each driven element tubes, at
similar mode as a coaxial cable stripped of braid is introduced in a
gamma rod.

It's not obvious how you'd be able to effect an impedance match with
this method. To be able to match an arbitrary impedance, you need to be
able to adjust two things which are at least partially independent. For
example, a gamma rod length and series capacitance. With this scheme,
you've got the length of the wires inserted in the tubes. What else can
you adjust? Wire diameter will give you some variability, but not an
awful lot, and it isn't easy to vary.

Roy Lewallen, W7EL