Nobody should ever pull the bench setup from an SPE/SMTS without having a talk about it – again another case of people running things who shouldn’t be. Another case of something not quite Kosher going on. Apparently, they were sent to China and then apparently they weren’t as they turned up on storage shelves a year or two later.
I have a CNC that still runs DOS because there is no abstraction and latency when hitting the 16550 port. I still have old work on floppies and Zip disks although are backed up. I have no problem with floppy disks – I had an external USB one for less than $20. Originally, I had an 8753D with the inbuilt S parameter kit but one day it disappeared for a new R&S. There was one 8753E in the building – and I wanted it – but I could never get my hand on that wonderful bit of kit. In the old 8753 and a cherry box cal kit it worked correctly every time. But that introduces its own inaccuracies in the S-parameters so its ok if its not too far off but when you go up frequency it was useless.
So, I also used the trick to wind the delay out to get it back to open. There was significant delay and the correction file loaded I believe was probably a correction file for particular R&S cables or to the plane of the connectors without cable connected. None of the instruments were cal’ed even though they thought they were. Now – I don’t know what file was loaded but I went through the building doing Cals on all of them that seemed unused and they were all the same – I always switch back to smith chart at the end of a Cal with the cable on and it wasn’t cal’ed properly. The trouble was Autocal boxes, expensive as they are – need de-embedding which means you need the right correction file loaded into the machine. In order to work you chose the Autocal feature in its menu and basically it did the rest – flicking between open, load and short and thru. They started out with fully automatic calibrators – a really nice addition from the old 8753, and I could use a pen drive to get the S-parameters out / no more floppy drives. Anyway, back to the Rohde and Schwarz bit of kit.