Cecil Moore wrote in message ...
Brian Kelly wrote:
. . . OK but 110 feet of feedline to an antenna at 40 feet is a whole
lot of feedline to deal with under normal installation condx. At least
around here in suburbia.
.. . . .

Cecil check me here if you will. I brought up a CAD program to sketch
your 80/75 dipole and ran into a puzzler as soon as I started to draw
it. Center fed 110' flattop, 110' balanced feedline. No problem. The
question arose when I tried to lay in the tuning caps. My
understanding is that the "input" sides of the two caps are connected
to each of the two wires at the "output" end of the feedline. Then the
"output" side of one cap goes to the shield of the coax and the output
side of the other cap goes to the center conductor of the coax. This
is not possible with a typical double-section variable BC-type cap
because one side of such caps is a common ("ground"). A pair of caps
mechanically coupled via an insulated shaft coupling but completely
isolated electrically from each other should work. Where's the
glitch??

w3rv