I notice that my Port B has flatten a little out after about 2.5Ghz and even more so after 5Ghz. This is seen when I do a verification after SOLT calibration against a known attenuator. This just started happening a few months ago spontaneously. I can also see this when comparing a thru using a high quality VNA cable measuring from Port1 to Port B and comparing to Port2 to PortA (See attached).
Im assuming that service menu #53 will pull this error out. I noticed that is specifies a 24" cable for this test, but all I have is a 38" Gore FD series VNA cable. I was hoping this would be ok?
Thanks for the help.
edit: I am seeing this response independent of different cables, connectors, etc.