Tube testers

Used tube testing is a crap shoot. An old tube can measure perfect and be at the end of it’s life the next day.

Is this true?  I always operated under the assumption that tubes rarely die quickly and instead, they just slowly get duller and duller.  I realize a tester may not always be definitive on how much life is left on the tubes and that your ears really are the best measure. Although over several years you may become accustomed to the very slowly diminished SQ so the degradation of SQ may not be immediately apparent over time. 

My approach has been to replace my tubes after several thousand hours and see how the new tubes compare.  If there isn't much if any difference then I put the old ones back in and milk out the rest of the life.  But I always thought it might be handy to have a tester just to get an idea whether the tubes may have much life left.  Perhaps a tester for that purpose is worthless?

i still have my military/hickok tv10 - good tester, will last longer than its users for sure... straight read on gm (no need to consult the conversion formula like the tv7’s require) - very useful in matching small signal tubes

http://www.vacuumtubes.com/TV-10.html

op needs to understand that most testers of this ilk will not/do not properly test power tubes such as kt88's at their normally high operating levels in actual amplification circuits... 

Vinylvalet,

The tube tracer looks quite interesting, but it appears to be a pretty complex and tedious process (I suppose it is fun to some people).  The Amplitrex, if attached to a computer, will also trace the tube.  I lasso like the fact that it does not require calibration.

I admit that there is some fun in using something like the TV-7, but also some terror concerning mis-reading the table or incorrectly setting the dials which could mean damaging the tube and getting a bad reading.

Having 19 tubes in my system I can say having a tube tester does comes in handy.  I can't imagine having to replace one tube at a time when something is not sounding right to find the bad one. 

uTracer3 for $247 vs Amplitrex for $2760 (as of yesterday). I don't think it has anything to do with fun, simply budget. You pay a hefty premium for convenience.