CTC-17 Screen control issue

[old_coot88]

Originally Posted by ctc17

... Would 15ma really make that big of a deal?

Oh yes indeed. The 6JE6 is already being driven to the max with virtually no "headroom" for overcurrent. It may be happy at 210ma but 225ma can spell doom. If the flyback doesn't fry first, what usually happens is- a hot spot develops in the glass of the 6JE6 which softens and sucks in at that spot. The tube goes to air in an instant, shorts out and kicks the breaker. Hopefully someone has not replaced the breaker with one of higher rating. I've seen sets come in with 7 amp breakers in place of the original.

If the tube is running at 221ma, keep a close eye on it and watch for any cherry red areas developing on the plate. Above all, NEVER, ever leave a vintage color set running unattended (even one with no overcurrent issues).