Hi. I'm using pna e8364c for measure the conversion loss of a mixer, using frequency offset. I make source and receiver power calibration, using frequency offset, evertithing ok, but when i want to save data, the pna shows a "inexpected error" message, and close the application. I repeted several times and it happens again, the pna shows an error message and close. Only once it showed more information, it said "unlocked signal" and another thing about swep ramp maybe. I'm using a psg e8257d as a local oscillator source for the mixer, with the cable connected to the 10 mhz reference(pna with the 10 mhz reference output, and psg with the 10 mhz reference input).