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Zenith Color Roundie Alignment with B&K 415
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01-06-2024, 05:12 PM
bhegges
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Join Date: Oct 2008
Location: Sioux Falls, SD
Posts: 140
Continuing along the next few steps went well.
Color Sync Alignment
Color switch on, color level set to the halfway point
Color Bar generator connected to antenna terminals set to Color Bar Pattern
Connect a .01uf capacitor from test point L to ground
Ground test point K
Adjust L34 for zero beat on screen and minimum movement of color bars through picture
(they were visible and a very slight adjustment removed these)
Next set VTVM to +50v DC range
Connect VTVM to test point V, adjust T20 top slug for maximum indication
(very little adjustment was needed)
Connect VTVM to test point V, adjust T20 bottom slug for minimum indication
(very little adjustment was needed here too)
Note T20 slugs should be on outside end of coil not towards the middle
Remove ground from Test Point K and .01uf capacitor from test point L
Color switch on, color level set to the halfway point
Color Bar generator connected to antenna terminals set to Gated Rainbow
Connect scope to test point R, adjust L29 Burst Amplifier Plate coil to match Figure 15A
(a small amount of adjustment was needed)
The second and forth bars should be equal in amplitude
Connect scope to test point S
If needed touch up T20 bottom slug quadrature coil to match 15B
(a small amount of adjustment was needed)
5th and 7th bars equal in amplitude
Note slug should require a very minimal amount of adjustment
Color Level Adjustment
Color Bar generator connected to antenna terminals set to Color Test Pattern
Connect scope to test point R and set color level to minimum
Adjust L18 for minimum color output at test point R
(a very small amount of adjustment was needed)
Essentially the picture should be black and white only
Range Check of Hue Control
Color Bar generator connected to antenna terminals set to Gated Rainbow
Connect scope to test point R and set hue control to maximum counter clockwise
First and third color bars should be equal in amplitude (second color bar maximum)
If not touch up L29 Burst Amplifier Plate coil for equal amplitude of first and third color bars
(a very small amount of adjustment was needed)
Connect scope to test point R and set hue control to maximum clockwise
4th and 5th color bars should be equal in amplitude
(they were)
Note if only the 3rd and 5th color bars can be made equal than this is acceptable
Connect scope to test point R
Set hue control for equal amplitude of 2nd and 4th (3rd color bar at maximum)
Now connect scope to test point T
Color pattern should appear as shown in figure 15C
(No pic but it matched)
Alignment Points
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