7-4
2-4-2.
Recording Chroma Level Check
(MA-315 Board)
Purpose:
Check the chroma signal level after passing through the Y/C sepa-
rating circuit.
If shifted, the image is roughened and another color may appear
on the edges.
Mode
E-E
Signal
Color bar
Measurement point
Pin
!¢
of IC201
Measurement equipment
Oscilloscope
Specified value
500 ± 80 mVp-p
Confirmation Method:
1) Confirm that the record chroma level is 500 ± 80 mVp-p.
Fig. 7-2-5.
2-4-3.
Sync. AGC Check
(MA-315 Board)
Purpose:
Confirm that the video level is correct.
Mode
E-E
Signal
Color bar
Measurement point
Pin
#•
IC201
Measurement equipment
Oscilloscope
Specified value
2.10 ± 0.14 Vp-p
Note:
Video output terminal must be terminated at 75
Ω
.
Confirmation Method:
1) Confirm that the sync. AGC level is 2.10 ± 0.14 Vp-p.
2-4-4.
X’tal Oscillation Frequency Check
(MA-315)
Purpose:
Confirm that the fsc is correct.
Mode
PB
Signal
Alignment tape SP color bar
Measurement point
Pin
%ª
of IC201
Measurement equipment
Frequency counter, Oscillo-
scope
Specified value
4,433,619 ± 96 Hz
Note:
Connect the frequency counter through a probe of high input im-
pedance (about 10 M
Ω
) and low capacity (10 pF or less).
Confirmation Method:
1) Confirm that the frequency is 4,433,619 ± 96 Hz
2) Confirm that the amplitude is 500 ± 200 mVp-p.
Fig. 7-2-7.
500
±
200
4,433,619
±
96 Hz
mVp-p
500
±
80 mVp-p
2.10
±
0.14 Vp-p
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