Tube tester...anyone own their own?

Al, thanks for your experience. What do you mean by essentially? I mean that you may not get a radical difference but you won’t get the same reading either.

I’ve been told by Roger Kennedy that the spec for a new (and there aren’t any new ones anymore), calibrated Hickock home type tester for Gm is +/- 15% That means that two testers both within spec can have a 30% difference measuring the same tube, worst case.

It’s also necessary to remember that most of these testers contain tubes inside the box with no ventilation, so how long the tester has been on affects the results. I’ve been told to never leave them on for more than an hour.

The Maxi-preamp 2 tester has an adapter for testing 6DJ8 family tubes but it still has the problem of the tube overloading the tester.

It depends on how serious you want to get.

If you’re really serious get the Amplitrex AT1000, about $3000

If you can live with less precision and control but want a modern computer type tester the Maxipreamp 2 is about $1,000. It will not test power tubes.

If you want a general idea if your tubes are good or bad and are reasonably matched get a home grade Hickock or TV-7DU for a few hundred $. You will not get repeatable results from these testers. Each time you test a tube you will get somewhat different results. These were basically designed to be good/bad testers for the TV repairman to bring to your home to replace tubes in your TV, console stereo or radio.

The lab grade Hickocks, 539C, 752A and others will give more accurate results and more control over the testing parameters, but will cost more than home grade and require quite a bit of learning to use them properly.

Also, the 6DJ8, 6922, 7308 family stresses out most home grade testers except the TV-7 family and you cannot get good results from most home grade testers.  The results just go off the charts.

I am not an expert and if any of the above is incorrect or incomplete, please correct me.