Can you measure the segment current ? For a given current, the brightness should be similar for tubes in the same condition. If not, there is a problem with manufacturing consistency. As VFDs age, they produce less luminous output. Some will develop visible dark bands nearest the filament(s), due to greater electron bombardment.
Mitch - You did a great job hiding your board where it's "really hacked up". Picture looks like a mature product that's been pulled off the assembly line. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/d5c3d50a-0ae7-4b88-acc0-e960f0a1f7f6%40googlegroups.com.