Is not that wire considered 'magnet' wire? Meaning the insulation is incredibly thin (enamel) and not designed to be ran around in a building or other. (used in transformers and such)
Have you considered calculating the exact impedance of the 17ga wire you need, and just adding enough extra length to the 16ga wire to be the same, looping the excess somewhere? Does this wire really need to act as an antenna?
where properties like speed-of-light, VSWR, dB/mile (or fathom) and similar more esotheric properties can be selected. I have not tried it, but it seems to be an interesting site...