53 bayous,
That's a yes and no question. It can make a difference if the antenna isn't near a 50 ohm impedance match, but not after the antenna is tuned for resonance and impedance matching.
To start with, since the antenna and feed line are not of the same impedance value the combination can give some odd value of impedance, or the correct value of impedance even though the thing isn't really tuned. If the feed line is something close to an electrical half wave during the tuning process then the mismatch while still apparent, will be compensated for to some extent (like the feed line not being there at all, sort of a direct connection to the radio). Once the antenna is close to a good 50 ohm impedance match, the the length of the feed line doesn't really matter (as long as it's the same/close as the impedances of the antenna and radio).
So, there you go. If you are aware of the mismatchs during the tuning process and can compensate for that with out the electrical half wave of feed line, then it isn't necessary. But in general it does make things easier...
- 'Doc