Clocking problem. I've been looking at the peculiar buffering on the clock signals (7417 open-collector buffer), and cant come up with a good reason why R11, R13, and R15 are present. I'd be especially concerned about unstable operation, as this circuit has positive feedback.
Are you using the exact parts,which seem to be 7400-series TTL, or did you use something similar, such as 74LS, 74LV, 74HC ? I suspect the circuit is very fussy about threshold values and output-drive-strength, so swapping devices that are functionally, but not parametrically equivalent, could cause problems. If you have a digital scope (you will need to capture the signal), best to start looking at clock-edges for odd behavior (ringing/glitches, incorrect amplitudes). -- 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 [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/263198f0-0f2d-48fc-977a-9d6f187ac346%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
