8. CONVERGENCE MAGNET ASSEMBLY
POSITIONING
Convergence magnet assembly and rubber wedges need
mechanical positioning following the figure 2.
8-1. COLOR PURITY ADJUSTMENT
NOTE : Before attempting any purity adjustments, the
receiver should be operated for at least 15 minutes.
1) Demagnetize the picture tube using a degaussing coil.
2) Vary the CONTRAST and BRIGHTNESS controls to
maximum.
3) Adjust RED and BLUE Bias controls (RJ04 and RJ24) to
provide only a green raster. Adjust the GREEN BIAS
control (RJ13) if necessary.
4) Loosen the clamp screw holding the yoke, and slide the
yoke backward to provid vertical green belt (zone) in the
picture screen.
5) Remove the Rubber Wedges.
6) Rotate and spread the tabs of the purity magnet (see fig-
ure 2) around the neck of the picture tube until the green
belt is in the center of the screen. At the same time, cen-
ter the raster vertically.
7) Move the yoke slowly forward until a uniform green
screen is obtained. Tighten the clamp screw of the yoke
temporarily.
8) check the purity of the red and blue raster by adjusting
the BIAS controls.
9) Obtain a white raster, referring "CRT GRAT SCALE
ADJUSTMENT" on the CRT board.
10) Proceed with convergence adjustment.
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