I'm a touch surprised that no one has suggested that the 7805 might be oscillating in the MHz region...
I would 'scope the +5V rail making sure that all input filtering is off... 78xx regulators were notorious for singing if they coukd - hence the essential 100n input & output caps mounted right up against it.... Nick -- 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 post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/2ca98382-8307-475f-a1ff-0cf667f157d7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
