I don't see the frequency per division scale, or at least it's not clear to me.
You'll need to adjust you sweep in the time domain to improve your resolution. And you'll want to set the maximum numbers of points, if it can be adjusted.
Take a look in vicinity of your carrier up to the digitizing rate. If you can see it in the time domain, any interfering signal with a specific frequency will show up quite readily in the frequency domain.
You're looking for any peaks besides the main carrier if it's something besides noise.
It wouldn't hurt to verify your signal source on the SA also. Make sure you have a single clean tone.