Service Adjustments - Zenith CM-150 Series Service Manual

PRELIMINARY SET-UP
1. Allow the receiver to warm up for 15 to 20 minutes.
2. Degauss the CRT.
3. Connect a crosshatch generator to the receiver and
"rough in" the static (center) convergence. Follow
the Convergence Procedure.
4. Adjust for best focus.
PURITY ADJUSTMENT
1. Purity tab positioning.
Set the 2 pole purity tabs together in the 3 or 9
o'clock positions and the 4 and 6 pole purity tabs
together in the 12 of 6 o'clock positions.
2. Move yoke to the maximum forward funnel position.
3. Now switch the crosshatch generator to a red field.
4. Pull the yoke toward the rear of the CRT neck cen-
tered or red raster is displayed.
5. If the red raster is not displayed as a pure red field,
adjust the 2 pole purity tabs until a pure field is ob-
tained.
6. Check for proper yoke tilt setting.
CM150/PV150

SERVICE ADJUSTMENTS

DIRECT VIEW
PURITY & CONVERGENCE SET-UP PROCEDURE
3-7
CONVERGENCE ADJUSTMENT
1. Release locking assembly.
2. Connect crosshatch generator to the receiver and ad-
just static (center) convergence as follows:
a. Adjust the 4 pole static control by moving the two
tabs separately to converge the red and blue lines
horizontally. Move the two tabs together around the
o
neck of the CRT (in a 45
ter position to converge the red and blue lines verti-
cally.
b. After the 4 pole control has been adjusted to super-
impose the red and blue lines on top of one another.
Use the 6 pole static adjustment to place the con-
verged red and blue lines over the green line. Move
the two tabs together around the neck of the CRT ( in
0
a 30 arc) from the top dead center position to move
the lines vertically. Adjusting the two tabs sepa-
rately will move converged beam to the left or right.
Using a cross hatch generator capable or producing
individual fields, adjust generator to produce a red
field. Use the purity tabs to center a red stripe.
arc) from the top dead cen-
GM CHASSIS