Tube Measurements?

I agree with Elizabeth. I've had occasion to test a considerable number of 50, 60, and 70 year old NOS tubes, on a Hickok dynamic mutual conductance tester, and they have tested as I would expect a new tube to test.

Also, the prices some audiophiles are paying for certain tubes of that period would seem to provide added confirmation.

Regards,
-- Al

Ditto the above.I have several 30-40 year old tubes that test to new tolerances.

That is good to hear. I've been building a "stash" of NOS with the next 20 years in mind, and wanted to be sure that how they tested when I bought them would be essentially how they will "test" when I using some years down the road. Thanks for you input.