Hi Doc & Co,
Do you ever consider to make a (simple) tube tester kit?
Maybe optimised just for popular tubes : UX4 300B, 2A3, 45; octal EL34, 6L6, 6V6 etc; Noval 12A.7 family, 5670, 6CG7, 6DJ8 family, etc
I have plenty tubes but can't test them. I know there are many vintage tester out there, but the complexity, need of calibration, lack of guide, etc put me off, its like the whole different can of worms. I'm sure many other would be on same boat as me.
Just a thought...