B&K 470 CRT Tester

[radiotvnut]

That's been my experience, as well and I think the yellow area is designated for testing color CRT gun tracking; however, I consider any tube that test on the yellow portion of the scale when reading emission to be weak (still usable; but, could be better). In some cases, I've had tubes that read in the upper end of the "BAD" range give a watchable picture. Recently, I had a BPC 2003 19" Orion that had a soft; but, still watchable picture. The tube tested in the yellow section of the scale; so, I "cleaned and balanced" the tube and it looked much better after that. When I encounter a weak tube, I usually perform the "clean/balance" function first. Usually, that will be sufficient to bring the tube up. If it's not, I'll move up to the more powerful "rujuvenate" function. I'm of the belief to only use enough power necessary to get the job done. With that said, the rejuvenate function on this tester is still safer than the older "atomic blast" testers.