[R-390] TV-10 tube testing questions

[wli]

Frank:

Not unusual to see JAN tubes show a higher micromho's than commercial grade tubes. What you will find that JAN tubes are more uniform than the others. JAN tubes are said to have thicker supports and thus are less prone to vibration damage.

IMHO, tube testers are best for detecting dead heaters and internal shorts. The functional tests have variable value, depending on who you speak to. Perhaps the test functional test is to see its actual performance in a circuit where it is destined to be used. 

Recently, I went thru the drill of running my spares thru the R390A; rank ordering them in S+N/N as outlined in past posts. Took a while, but now I have a listing of all of my spares for the future.

W. Li
Mercer Island, WA