7JP4 Tube Grading

[old_tv_nut]

Originally Posted by Electronic M

RCA both made new CRTs, and rebuilt them. If both those operations were under the same roof, then it would not be out of the question to take an old cleaned faceplate walk it over to the NEW tube line phosphoring station and get it done.

This may have been possible if the faceplate was never fritted to a funnel, but I have strong doubts the two could be separated successfully once joined.

Edit: I see the same comment above. A secondary thought is that after the phosphor deposition was complete, and before joining the funnel, if there were significant flaws, the face assembly could be reprocessed, possibly discarding the shadow mask if that caused the problem (like missing holes). But it would take some kind of intrusive investigation of a factory to determine if this was done and the resulting tube was "Grade A" instead of "AA." This seems like a typical kind of legislative language mistake due to misunderstanding of technical issues.

[jr_tech]

Originally Posted by old_tv_nut

A secondary thought is that after the phosphor deposition was complete, and before joining the funnel, if there were significant flaws, the face assembly could be reprocessed, possibly discarding the shadow mask if that caused the problem (like missing holes). But it would take some kind of intrusive investigation of a factory to determine if this was done and the resulting tube was "Grade A" instead of "AA." This seems like a typical kind of legislative language mistake due to misunderstanding of technical issues.

Guess that it depends on what is meant by "new"

I would argue that the faceplate panel has never left the factory, never been turned on is *still* new. I would think that any phosphor deposition process would have "rework loops".... first pass yields should have been high, but I'm guessing *not* 100%... seems like tubes assembled with these panels would rightly be marked "AA", IMHO.

jr