In article .com,
Steven wrote:
More crossposting.

Tubes can be fickle things. How do you guarantee 50 yo stuff like that
in lots or 20?

You know, I almost never see any mention of a guarantee for tubes, except
occasionally on HF transmitter 'final' tubes.

That aside, it is _quite_ possible he has a tube tester. Maybe even a working
50-year old one. grin