You can take a regular CRT and rewind the deflection coils on the yoke to work as a vector CRT display. Arcade Jason has a good video on how to do this.
Then you need a vector generator if you don't have an OG vector game. This one on Github is pretty good and can be connected to either an oscilloscope or vector monitor.
If you use the vstcm to drive your rewound crt, you still have a problem. The deflection coils are very low impedance (around an ohm I think), so you need an amplifier stable at very low impedances that can generate a voltage sufficient to get deflection across the full screen in x and y. I think Arcade Jason was working on one of these too but I don't think it is out yet. ElectronAsh was working on one as well but I don't think he finished it.
You can take a regular CRT and rewind the deflection coils on the yoke to work as a vector CRT display. Arcade Jason has a good video on how to do this.
https://www.youtube.com/watch?v=Ci9qiGVMF7s
Then you need a vector generator if you don't have an OG vector game. This one on Github is pretty good and can be connected to either an oscilloscope or vector monitor.
https://github.com/english1234/vstcm
If you use the vstcm to drive your rewound crt, you still have a problem. The deflection coils are very low impedance (around an ohm I think), so you need an amplifier stable at very low impedances that can generate a voltage sufficient to get deflection across the full screen in x and y. I think Arcade Jason was working on one of these too but I don't think it is out yet. ElectronAsh was working on one as well but I don't think he finished it.
https://www.youtube.com/watch?v=tybGveLtlkA
https://github.com/ElectronAsh/Vector-XY-Deflection-Board
Or you could follow iz8dwf's amazing series on how he built a black and white vector monitor.
https://www.youtube.com/playlist?list=PLbKEoUHtoVucsrySlogDz...