We have a small team that is building an open source DIY Curve Tracer. Not a Tek577 replacement per se, but it can do most measurements and is a lot better than anything else we found. We are close to the final stages and have a fully operating CT that I'm making measurements with.
If you're interested, have look on my blog. Eventually everything will be shared on Github and here too but we'll wait until we have finished the project.
https://www.paulvdiyblogs.net/2021/03/building-curve-tracer-version-3.htmlIf you have comments or inputs, leave them here to share because my Blog is limited in that respect.
Enjoy!
Paul