Focus Adjustment; Purity Adjustment - Sylvania SRT2227S Service Manual

17. Focus Adjustment

Purpose: Set the optimum Focus.
Symptom of Misadjustment: If Focus Adjustment is
incorrect, blurred images are shown on the display.
Test Point Adj. Point
--- Focus Control
Tape M. EQ.
Pattern
---
Generator
Note:Focus VR (FBT) - Main CBA FBT=Fly Back Trans-
former
1. Operate the unit more than 30 minutes
2. Face the unit to the East and Degauss the CRT
using Degaussing Coil.
3. Input the Monoscope Pattern.
4. Adjust the Focus Control on the FBT to obtain
clear picture.
Mode Input
Mono-
---
scope
Spec.
See below
5-7
The following 2 adjustments normally are not
attempted in the field. Only when replacing the
CRT then adjust as a preparation.

18. Purity Adjustment

Purpose: To obtain pure color.
Symptom of Misadjustment: If Color Purity Adjust-
ment is incorrect, large areas of color may not be
properly displayed.
Test Point Adj. Point
Deflection
--- Yoke Purity
Magnet
Tape M. EQ.
Pattern
---
Generator
GREEN
1. Set the unit facing east.
2. Operate the unit for over 30 minutes before adjust-
ing.
3. Fully degauss the unit using an external degauss-
ing coil.
4. Loosen the screw on the Deflection Yoke Clamper
and pull the Deflection Yoke back away from the
screen. (See Fig. 6)
5. Loosen the Ring Lock and adjust the Purity Mag-
nets so that a red field is obtained at the center of
the screen. Tighten Ring Lock. (See Fig. 5,6)
6. Slowly push the Deflection Yoke toward bell of
CRT and set it where a uniform red field is ob-
tained.
7. Tighten the clamp screw on the Deflection Yoke.
Mode Input
---
Color
Spec.
See below.
Figure
RED BLUE
Fig. 5
L6200EA
Red