I want to thank each of those who responded. To answer one question, these
tubes are NOS JAN's made by Cetron from Nebraska. The seller has offered to
replace all four.
What I was looking for were experiences running the tubes up to the 2KV level.
I do have my gear on permanent Variacs to maintain voltage. I suspect this one
tube was defective to begin with. As the seller said, the matching was done at
low voltage so they would not have seen this tube take off. As I said I didn't
begin to see a problem until the 400 -600 volt level. Running the tubes with a
little color wouldn't bother me. By the way I've been licensed since 1956.
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