21AXP22 Vs 21FJP22

[old_tv_nut]

Originally Posted by Rocket

Most interesting! So the A on the end has the Rare earths then huh? and I take it that is better?

For the reason that the red phosphors before rare-earth red were only about half as efficient as the blue and green, so pictures were dimmer and current ratios in the three electron guns were not equal. Rare-earth red phosphors allowed the currents to be much more nearly equal, with less highlight blooming (defocusing), so a better tradeoff of sharpness vs. brightness.

The unequal current needs were also partially compensated by specifying a cyan-blue white color ("9300K + 27 mpcd") which also contributed to the mismatch of colors from what was intended per NTSC specs, and unfortunately made variations in transmission more visible.

Edit: one of the secrets of Zenith sets that made the colors look different (and most would say better) was use of a less blue white point.