The Set: Pete Deksnis's Site about the CT-100
Restoring a Vintage Color Television Set
The above scan of the 1962 GE picture tube manual correctly shows the RCA 15GP22 and CBS 15HP22 as 45-degree deflection angle designs, which resulted in the great overall length of these tubes for so small a picture. The 19TP22 was a 60-degree design. Therefore, it is nearly two-inches shorter even though the screen is significantly larger. Note, also above, all three tubes use electrostatic convergence -- a practice quickly dropped, as it required extensive high-voltage circuitry to provide the modulated 10-kV convergence signal.
These were the last tubes to use a flange for the high-voltage connection. The metal-funnel of the 21AXP22 used a lip; finally, the all-glass 21CYP22 returned to the cavity connection used extensively on black and white picture tubes.
Typical Operating Conditions, see table below, lists the same 20-pin base and pinout for all three electrostatic convergence tubes. Twenty-pin bases were needed to provide high-voltage isolation for the convergence signal pin. Six of the actual pins -- 10, 11, and 12, then 14 to 16 -- were not installed on these tubes, thus keeping pin 13 well away from the others.
Non-electrostatic convergence designs used a 14-pin base.
I found it interesting that the newer RCA 21AXP22 (lip) and older CBS 19VP22 (flange) used the same base and had the same pinout. There is a picture of the 19VP22 elsewhere on this site; it is easily located with the search engine.