John Fields wrote:

BTW, from another thread and just as an aside, I went over to my
friend's sign shop and checked some known-good neon sign transformers
using the same meters I used to check the ones I have here, and it
turns out my transformers are defective. :-(

Sorry to hear that. I was surprised that I couldn't simply Google
this. But the elusive neon sign transformer voltage current curve
remains uncaptured.