Tube tester...anyone own their own?

I use a Sencore's grid leakage test to find tubes that otherwise test fine for emissions including fine on Hickok testers. Let warm sufficiently for 15 minutes or so before test...i used to also have tubes that tested fine in my arc preamp, but were clearly not so...the sencore now catches those tubes.

If you need to have work done I would recommend Bud Allen without hesitation. You should do some research on former clients of Roger at Alltubetesters before sending him anything!

I have: Hickok 539C, Cardmatic, Heath TT-1, Maxi-Matcher (power tubes) and my favorite is my Triplett 3444. 

I have checked out a few tube testers, but so far none can test the KT150 tube....which needs a 600 volt+ test. Anyone have any recommendations?

I would back up that statement about checking on Roger at Alltubetesters. Let the Buyer beware... I currently own a Hickok / Western Electric KS15560 rebuilt by Paul Hart in Atlanta, he is an Electrical Engineer (retired) and does great work, he has a number of testers he can rebuild to sell (pkharthave@gmail.com). Also own a Hickok 752A (rebuilt by Paul) and Jackson 658. One thing about Paul is he can modify a tester, mine have been modified to run with a Variac which increases the accuracy on all tubes, especially high heater current tubes because there is no loss in the line adjustment pot. Mine can also can measure plate current. As daveyf above says, if you want to test at 600 volts you'll need a specialized, modern tester. Mucho $$$$. But the older Hickoks, if calibrated, do a fairly good job within their voltage limitations.

Agreed, I have heard that Paul is very good. This comes from several discerning peers as well as clients.