7.5.4 Apply proper r-f age and i-f age bias voltages,
as well as the required bias in the chroma
section.
7.5.5 With PROBES switch in the DIRECT position,
turn on the ADJ PIX (39.75) and ADJ SND
(47.25) markers and center the sweep on the
oscilloscope using the CENTER FREQUENCY
control and using maximum sweep width.
7.5.6 Increase the 415 output until a response curve
of the proper amplitude is obtained.
7.5.7 Turn on the SOUND (41.25) marker and, using
the fine tuning control of the television re-
ceiver, locate the response curve so that the
sound marker falls in the sound notch of the
response curve.
(See Figure 4.16A and
B, repeated)
Increase scope gain and Model 415 output as
required for additional resolution as shown in
Figure 4.17. Restore scope and 415 levels.
SOUND
41.25-
(71.75)
CHROMA
42.17
(7D.83)
PIX
45.75
(67.25)
ADJ $ND
47.25
(65.75)
A. Fine Tuning Improperly Adjusted
7.5.8 When the above steps are performed the tilt
adjustments for the i-f response can be per-
formed.
7.5.9 With the SOUND (41.25) and the three CHRO-
MA (41.67, 42.17, 42.67) markers on, reduce
sweep width and center the chroma portion
of the response curve.
7.5.10 Place CHROMA switch to ON position.
7.5.l l Place PROBES switch in DEMOD position.
Perform the required signal level adjustments
as outlined in Par. 7.4.2.
7.5.12 Adjust 415 output as required to obtain speci-
fied peak-to-peak chroma response amplitude.
7.5.13 Perform the required tilt correction adjust-
ments.
PIX
---ADJ SND
SOUND
B. Fine Tuning Properly Adjusted Using Sound
Marker for Reference
Figure 4.16 (Repeated) Setting Fine Tuning Using Sound Notch of Response
Curve. (Channel 4 Marker Frequencies Shown)
A. Enlarged Response Curve Using
Vertical Marker Display
B. Enlarged Response Curve Using
Horizontal Marker Display
Figure 4.17 (Repeated) Increasing Sound Notch Resolution to Adjust Receiver Fine Tuning Control
57
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