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Purity and Convergence Procedure
Adjustment is necessary only if the CRT or the
deflection yoke is replaced or if the setting was
disturbed. The complete procedure consists of:
1. Vertical Raster Shift Adjus tme nt. (Only for Models
with Purity/Convergence Assembly with 4 Pairs
of Rings).
2. Ini tial static convergence.
3. Se tting the purity.
4. Fina l static convergence.

When the CRT or the Yoke is Replaced

Place the yoke on the CRT neck (do not tighten
the clamp).

Place the vertical raster shift tabs at 3 o’clock (90

o

from

the purity and convergence tabs)

Turn the Receiver ON. Operate the Receiver for 60
minutes using the first Purity Check field (white screen)
to stabilize the CRT.
Fully degauss the Receiver by using an external
degaussing coil.
Slide the deflection yoke back and forth on the neck of
the CRT until it produces a near white, uniform raster.
Vertical Raster Shift Adjustment (Only for
Models with Purity/Convergence Assembly with 4
Pairs of Rings).
Apply a green pattern with a horizontal line, adjust the
Deflection Yoke so that has no tilt, then secure it.
Adjust center line of the pattern with the mechanical
center of the CRT, this center is determined by two
marks at the side edges of the screen. To adjust the
line, once the vertical raster shift tabs are p lace at 3
o’clock to reduce its magnetic field effect (see Fig. 9
and Fig. 10) open the tabs the same angle from th e
center, until the center line of the pattern becomes a
straight line, centered with the marks of the CRT. (see
Fig. 11)
G3 G4
Purity Rings Centered
Over G3/G4 Gap
R&B Convergence Rings
R&B&G Convergence Rings
Vertical Raster Shift Ring
Figure 9. Positioning of Purity/Convergence
Assembly (4 Pairs of Rings)
90o
Purity Rings
Vertical Raster
R&B Convergence Rings
R&B&G Convergence Rings
Figure 10. Positioning of Purity/Convergence
Assembly (4 Pairs of Rings)
Shift Rings
Vertical Raster Shift tabs
Open the
same angle
from center
Figure 11. Vertical Raster Shift Adjustment
(4 pairs of rings assembly)
Center Marks
from pattern
Center line
Mechanical