Hi all. I have a 10BP4 with strong emissions down to 4 volts, no shorts but the cutoff is poor. How does a tube get this way, what is going on inside the tube that might create this condition, what kind of picture quality can I expect and is there anything that can be done to remedy it?
Thanks VKers!

The cutoff test measures the effect of the control grid. If you have poor cutoff, the contrast may be poor. I would just try the CRT in the set and see how it performs. The tester may be lying.

I had a tube with absolutely no cutoff in a RCA set and it actually worked ok and looked fine.