I have E5071C configured to measure the phase difference between two oscillators on channels A and B. The sources of the VNA channels are, of course, disabled, and the reference input is the same reference for the two oscillators.
The phase measurements for the two oscillators exhibit discontinuous phase jumps, but always in tandem, so that the difference measurement shows no discontinuities. Several measurements and configurations have confirmed that it is the behavior of the VNA, and not present in the source.
What is the explanation for this? The phenomenon is causing heartburn for the project manager.
Many thanks in advance,