Westinghouse K840CK15 Restoration

[Electronic M]

One possible point of contribution to the grayscale issues is difference in phosphor efficiency of a 15G and a 21FB CRT. Phosphor efficiency changed substantially between the two.Circuits that were meant to balance colors on a 15G where colors were inefficient across the board, and the phosphor efficiency varried radically between the weak red and IIRC the strong blue probably are a ways off of optimum for later phosphors.