My new CRT driver board is coming along rather nicely. Tonight I tested it out with a 5″ CRT. It uses a P7 radar phosphor so it looks bluish white with a sickly yellow persistence.
The pattern is a Lissajous figure (LISS-uh-joo). Take two waveform generators and connect one to the X input and the other to the Y input, and you get all sorts of interesting patterns. Since the CRT driver board is not available as a kit (not yet, anyway!) you can duplicate this with an oscilloscope and two function generators.
There’s some interesting math behind Lissajous figures, but I’m more interested in building 3KV power supplies.