I'm working on a Solid State Calibration Vacuum Tube (SSCVT) right now, I have one design that works on my Roetest (
www.roehrentest.de) as well as on my VCM163 but I still haven't tested it on my AVO Mk IV since it is in storage and will take some time and effort to dig out plus it will need to be calibrated to show correct measurements. The VCM163 and the Mk IV measures a tube in different ways so I will have to make sure that it works on both. I have another design that works on the Roetest but I will see if I get it to work on the VCM163, still some bugs to kill, this design might work better on the Mk IV though.
I'll publish something here on the forum when I am finished testing it on my Mk IV but that might unfortunately take some more time since I am in the middle of changing jobs right now.