have several pro grade tube testers.
I used to repair tvs for a profit making hoby. I have a Sencore mu-150 suitcase version a TV shop I got leftovers from gave me, a 1953 military i77b multi box testor that can test accurately almost any tube made if its in the manual, that did get updates. A 30's beautiful wood cased tester that can test all the old antique stuff current when it was new.
I also have two Beltron picture tube rejuvinaters that were very handy in making dead CRTs come back to life and show a good picture again. I have thousands of tubes too.
I started doing this in high school in the early 70's so having lots of spare used tubes helped me fix the sets I usually ended up with and I could sell a barely working one for 50 bucks, nice ones were 150.
I did tubes, hybrids, and solid state as that was what was common.
Oldest color set I fixed was a 61 Sylvania, my favorites were the Zeniths, they always looked good and were somewhat easy to find parts for, plus they held up forever.
It's not worth it now, nobody does board level repairs, and used sets don't sell anymore with all the throw away flat screens.
I hate to toss this stuff though even though most of it is useless now, nobody makes a old school crt based TV anymore.