Don Henschel
Forum Participant

Actually I wouldn’t worry much over that one Gary as that price isn’t overly expensive IMHO and as you will notice there isn’t much to them other than a mess of sockets. I have a pair of very good Griefkit (my late fathers name for Heathkit equipment he mostly gravitated to) tube testers and while in storage in my possession possibly from slightly high humidity while in a garage the rotory and other switches developed a mild oxidized film but contact cleaner solved this problem. If it has 4 pin and up with all the paperwork for settings it will be most useful. As for calibration one can test an assortment of brand new NOS tubes along with ones appearing to be performing very well in a working set for a comparison. Where I’m looking and are generally very expensive are the testers that can handle CT8 tubes which my early European sets have.