Hi Martin, Marcus,
I am using a N200 + WBX.
Gain set on the USRP is equal to 5 dB.
Changing the power of the input signal does not change anything. Moreover the output of the signal generator is sent (via a 2way power divider) to a spectrum analyzer and the input signal is ok.
I made some other test.
I always have the two replica also with a LO different from zero.
Anyway playing a bit with the LO value one of the two replica disappear probably because it goes outside the IF band.
In any case I can't understand why the replica is there (?).
Concerning IQ imbalance .... how can I measure and compensate ? Using the calibration utility ?
ciao
Luca