Unknown Device?

[TVBeeGee]

What is this thing and what might it be used for? It's got calibrated knobs on each side and RGB color filters inside. Very strange.

https://www.ebay.com/itm/Vintage-RCA.../254580426011?

[MIPS]

It looks like a prism loupe for color adjustment.

[old_tv_nut]

It's hard to guess how this would be used for everyday repair/adjustment work. If it were a service instrument, it seems to me it would be marked as such, not with the Lancaster label.

It appears the red and blue pieces are rotatable and the green is fixed.

My wild guess: an instrument to measure center convergence of the tube without any static or dynamic convergence correction components installed, to see if it is within specifications. It would be used by TV manufacturers who bought tubes from RCA.

[old_tv_nut]

Images 7 and 8 show "QA LAB" melted into the plastic case with a soldering iron tip.

So, I think this was a 4X magnifier that had the filters and calibrated knobs added by RCA's quality assurance lab at Lancaster. Used by them internally, not by purchasers of their tubes.

[old_tv_nut]

Another clue is the transparent base, useful for a device originally intended for viewing prints, rather than CRTs.

I'd be curious to play with it, but not $100 curious.

[old_tv_nut]

[dewickt]

I used to use them every day in my CRT/Yoke lab, set the center of the CRT for perfect convergence then measure points on the face of the CRT for mis-convergence.
A way to match the yoke to the CRT and monitor quality during production.

[old_tv_nut]

Bingo!

Thanks!