I used to pull tubes from every item in the house just to take them down to the Thrifty Drug Store and test them. I probably ruined more tubes than I realized - it drove my Dad nuts.
Drug store testers were "service tube testers" and only performed cathode emissions testing, which is really only good for telling you if a tube is good or bad, in a vague way. If you are going to collect more than a few NOS or used tubes then you are going to want to use a mutual conductance tester.
I won't get into which tester to select because I don't want to write a book and also there are guys on this forum who know a hell of a lot more about this than I do.
Drug store testers were "service tube testers" and only performed cathode emissions testing, which is really only good for telling you if a tube is good or bad, in a vague way. If you are going to collect more than a few NOS or used tubes then you are going to want to use a mutual conductance tester.
I won't get into which tester to select because I don't want to write a book and also there are guys on this forum who know a hell of a lot more about this than I do.