(No.YA328)1-27
4.7.8 PURITY AND CONVERGENCE
PURITY ADJUSTMENT
Note:
The final adjustment of CONVERGENCE must be done after
the FOCUS adjustment. (CONVERGENCE is changed by
FOCUS adjustment.)
When makes difference by FOCUS adjustment, should be
reconfirming PURITY adjustment.
(1) Demagnetize CRT with the demagnetizer.
(2) Loosen the retainer screw of the deflection yoke.
(3) Remove the wedges.
(4) Input a green raster signal from the signal generator, and
turn the screen to green raster.
(5) Move the deflection yoke backward.
(6) Bring the long lug of the purity magnets on the short lug and
position them horizontally. (Fig.2)
(7) Adjust the gap between two lugs so that the GREEN
RASTER will come into the centre of the screen. (Fig.3)
(8) Move the deflection yoke forward, and fix the position of the
deflection yoke so that the whole screen will become green.
(9) Insert the wedge to the top side of the deflection yoke so that
it will not move.
(10) Input a crosshatch signal.
(11) Verify that the screen is horizontal.
(12) Input red and blue raster signals, and make sure that purity
is properly adjusted.
Fig.1
Fig.2
Fig.3
• P/C MAGNETS
P : PURITY MAGNET
4 : 4 POLES (convergence magnets)
6 : 6 POLES (convergence magnets)
CRT
WEDGE
P
P / C
MAGNETS
4 6
DEFLECTION
YOKE
Long lug
Short lug
PURITY MAGNETS
Bring the long lug over the short lug
and position them horizontally.
(FRONT VIEW)
GREEN RASTER
CENTRE
