Hello Cristian,
How are you measuring the frequency offset? Are you in sweep measurement mode and using markers? If so, what is your RBW?
Can you verify the frequency offset using tools such as the Utilities->Frequency Difference meter, or the carrier offset readout in Analog Demod measurement mode? In both measurements you will want to set the center frequency and reference level for your input CW.
I look forward to your response.
Regards,
Andrew
