If you mean a bw crt, the consensus on the crt gaming sub is that it's too expensive and there are a lot of undocumented secrets :( I've found some Chinese fac

If you mean a bw crt, the consensus on the crt gaming sub is that it's too expensive and there are a lot of undocumented secrets :( I've found some Chinese factory which claims they can do it, but they seem to be using new-old-stock tubes. I believe EU regulations regarding lead in consumer products prevent this too.