vovi: Even in this setup you could measure very low DUT distortions, but you have to count on the DUT having a very flat FR in the distortions band. If the DUT rotates the distortion generated by the DAC side, it will not be properly subtracted by the corresponding ADC distortion and the actual DUT distortion (the one we want to measure) will be vector-added to the residual fake distortion.
That's why splitting the distortions and thus generating a clean sine signal which behind the DUT will contain distortions introduced by the DUT only.
How long does your manual compensation hold valid and to what extent? IME a major portion is basically fixed and repeatable, only minor deviations throughout time, due to temperature I guess.
That's why splitting the distortions and thus generating a clean sine signal which behind the DUT will contain distortions introduced by the DUT only.
How long does your manual compensation hold valid and to what extent? IME a major portion is basically fixed and repeatable, only minor deviations throughout time, due to temperature I guess.