Testing a 10BP4

[prewtv]

I have several 10BP4s I tested on a SENCORE BIG MACK CRT tester.
You set FIL, CUT OFF RANGE, CUT OFF or tracking on a meter, and then check emision. Out of 3 only 1 sets correct on cut off, others almost make it, but all test good in the green and pass life test.
Not to make cut off, what does that mean?
Let all warm up 10 min.
Have no working chassis to try CRTs in yet.