Harlock, if I read your question correctly, you are asking if the antenna will need to be tuned as you move about in frequency from 50.0 to 50.3Mhz.
.
A simple half wave dipole on Six is sufficiently broadband'd to be essentially "flat" SWR-wise over that entire range. Cut and adjust your antenna for 50.15 and it will not need any further attention.
.
Most of your voice operation will be between ~50.125 and 50.200- a very narrow range,one not likely to expand until the F-skip returns (so don't hold your breathe

)
.
It sounds to me like you are quite new to Six. Its a fun band, but it take a bit of effort to get into it. Here, for what it is worth, are some of my insights on the band-
.
Set your radio on 50.125-and listen, listen , listen-- This is the US calling frequency. If anything is happening, it will show up there first. By Gentleman/Gentlewoman's (

) agreement, 50.110 is limited to non-US DX calling... Most people I know don't operate voice between 50.100 and 50.125- though there is no rule against it-- and CW is popular between 50.090 and 50.110.
.
But don't let this narrow range of .125 to .200 keep you from QSY'ing higher-- especially since you are running QRP... the neighborhood about "125" is Six metre "kilowatt alley"-- if the band is open, move up and find a open spot, and call CQ- others will find you no problem.
.
A low power transceiver with a dipole is starting out pretty handicap'd, but certainly workable. Mark your calendar for the June VHF contest- there, on that weekend- is where you'll find what your station is capable of. You will hear dozens and dozens of stations that are like May Flies- there for that brief period and then -gone--- not to be heard again until next year.
.
I hope you come to love the ban, Cowboy.... good luck to you!
.
.
.............................................CF