On Wednesday, 11 February 2015 11:28:07 UTC, Dalibor wrote: > > Nick: Hi, I use TM because I was lucky to get few for reasonable price > from local bancrupted research company, together with all the accessories. > Diff pump are much cheaper, they need practically no maintenance (when used > right way), but they it takes much longer time to start it up and also the > cool down. TM is more flexible in this way and saves a lot of time, > especially during development. And TM pump also provides oil-free > operation, which is good, but essential matter in nixie tube making. >
Hi Dalibor - thanks for the feedback. I have no doubt that a TM is a lot faster & cleaner, but they do spin ever so fast and still need maintenance... Diff pumps with suitable low vapour-pressure oil, e.g. a polyphenyl ether, which is changed/maintained properly should be fine - no oil should get back to the glass if you get the sequencing right and the bombarding (or equivalent) should remove any potential organic matter - I can't see that more than a few molecules should ever get back to the tube... Modern multi-stage diffusion pumps with a cold-trap will reach 10x10-13 atm, which is far far below what we need - When nixies were commercially manufactured, did Burroughs/National etc. use TM or diffusion pumping? Cheers 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 [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/20d654ef-5a7e-4769-b84c-285fa968442b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
