I'm a bit confused by your description. Is this a folded dipole, 40
feet long, with an added resistor in the conductor which would normally
be unbroken, inserted directly opposite the feedpoint? Or is it
something else? Why not just a 40-foot-long center-fed doublet, with a
tuner at the transmitter end? What bands do you want to use your
antenna on? What do you want to accomplish with it? (DX, local,
intermediate range, ...)

Cheers,
Tom