Aaand a TEAtime-story with a happy end:
I aquired an Anritsu Sitemaster 251B for the explicit purpose of lending it to my company (told somewhere here). But then the fun started.
Battery missing - check. Was known and is available.
It came with two leader cables: a super flexible, low PIM heavy duty SUCOFLEX and one that looks like RG400. I tried the Sucoflex - and couldn't measure anything. I would have gotten better results with a random piece of TV coax from a garbage heap, as it is completely dead. I recalibrated and retried, but it took me a day to discover that the supposedly better cable was the culprit.
Then came the Software issue: the measurements must be documented of course. I downloaded the latest SW and installed it on a W7 PC. Nogo. (+1day) I phoned support (+2days) and was somehow misunderstood as having a 251C. So I was send off to a full blown jackalope chase with the wrong SW, the wrong config and the wrong Baudrate.
Turns out that this SW never worked under W7 and never was able to handle the 251B. (contrary to the manual)
Got the old SW and found out (after another day) that it works under XP and W10, but nothing in between. And got send off again, with TWO different wrong solutions. For a moment I held the device and pondered the question if a sledgehammer or a shotgun would yield greater satisfaction.
Finally, I got behind the Baudrate BS and it works.