CBS and RCA Color Status 1950-51

[miniman82]

This is before the all glass tube was envisaged, they are talking developmental tubes with metal shells like the C-73547 and C-73293.

http://www.earlytelevision.org/rca_developmental.html

It's not technically accurate to say they were built into a 'standard' 16AP4 shell either, it would be more descriptive to say that they were 'based' on a 16AP4 shell since a 16AP4 lacks the welded rim them color tubes had. This was necessary, due to stuffing the phosphor dot plate and shadow mask inside the front half of the tube. The color ones also had much larger and longer neck glass to accommodate the 3 gun structures, so the aft section of the tube was altered from it's B&W counterpart as well.

^That's a C-73547 in my avatar, before it went to air.