A Set I Haven't Seen Discussed

[West]

I think once RCA had a 21-inch tube, it was all over for the 19VP22. RCA had been promising a 19-inch tube, which would use the same cumbersome construction methods as the 15GP22.

But when Norman Fyler and William Rowe of CBS-Hytron showed their greatly simplified Colortron, RCA had to bite the bullet and pay royalties to CBS.

So I think RCA decided to go straight to a 21-inch tube to keep other manufacturers from adopting the 19VP22. This is why, in my thinking, the CT-100 was quickly modified to take the 21-inch tube (the 21-CT-55) as an interim measure, just to get their tube out there, allowing more time to develop the simplified models with the CTC-4 chassis.