Thanks Jr. Tech- Just wanted to check before blasting ahead.
It only took about ten minutes to swap out the tubes. The original 21AMP4 must be the one it was built with-a 1954 date code, and it was purchased in November of '55. I photographed the cathodes of the tubes, as there is something I have noticed in my collecting. It seems to be that the cathode/g1 of well used crts darken as they age. In the case of my old one, look how it has turned almost black from use, while the 21CBP4's (has a date code of '59) cathode/g1 is the same youthful silveryness of the rest of the tubes' elements.
As it is, nothing is hooked up to the new crt's focus pin #6. It looks fine without it. I removed all of the magnetic focusing hardware, and of course, the ion trap. It's nice finally having a bright, useful image on this set! Glad to have it back as a daily driver again!
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