When I was a kid, every neighborhood had a place with a tube testing machine. Ours was at a neighborhood "candy" store. I remember going with my dad - he brought a bunch of tubes from our TV set, tested the tubes one by one, and any that read "bad" he replaced- replacement tubes were in an integrated cabinet that was part of the tube tester.
Seems to me, having a tube tester, rather than a money looser, could lead to tube sales.
Seems to me, having a tube tester, rather than a money looser, could lead to tube sales.