I use here an AVO tubetester type V.C.M. 163 an AVO tubetester type MK4 and I have an AVO tubetester CT160

With this kind of tubetesters you cannot test:

stabilising and referencetubes and neontubes
rectifiers with cold cathode
cathode-raytubes and camera tubes
gasfilled tubes (thyratrons,indicators,counter etc)
photosensitive devices and resistor- & relaistubes
transmitting tubes from 250W and more and switchingtubes
microwave tubes and nuclear devices

Stabilising and referencetubes I can mainly test with a homebrew tester