Tube testers for 6922, 12ax7, etc, etc,
Looking for some advise with tube testers for 6922 and 12ax7 tubes. I'd like to buy one but don't have a clue as to which kind to buy, I see many types on ebay for resonable prices. I hear they need to be calbrated every so often. The concerne I have is buying one off ebay and getting some one's flea market special! I guess I'd like a tester that test for shorts, gases, mutual conductance, etc, etc. I would like to spend around $200 for a simple to use tester. Can this be done or am I spinning my wheels here and need to spend way more? Do any of you know a source for testers? Thanks in advance.