dancub:Most entry-level tube testers are old; the new units tend to be feature-rich and expensive. Cheaper, old tube testers generally have minimal features and capabilities, with emissions being the most common. Better is a transconductance tester, and good ones like my Hickok testers can test for shorts, leakage, gm, remaining life (estimated), gas, and other issues. I have a B&K from the 1930’s that is good for minimal tests on really old tube types, and a cheap Eico emissions tester that is a quick go-to for pass/fail tests.
If you only need to see if a tube is good or bad, a cheap old tester might be OK, but often it’s just best to use "tube substitution", a term all those familiar with working on tube gear will be familiar with. Having a known good replacement, even a marginally-good tube, can be very useful if you suspect a particular tube has gone bad.
If you only need to see if a tube is good or bad, a cheap old tester might be OK, but often it’s just best to use "tube substitution", a term all those familiar with working on tube gear will be familiar with. Having a known good replacement, even a marginally-good tube, can be very useful if you suspect a particular tube has gone bad.