Sony DNW-A22 Maintenance Manual page 204

6-3. DM-89 Board Replacement
10. PB Frequency Response Adjustment
Measuring equipment: Composite waveform monitor (terminated with 75 Z) -- for Y
Oscilloscope --------------------------------------------------- for C
(1) Set No.2 (C MUTE) of S1/TBC-23 (B-1) to ON.
(2) Enter A32 : DM VR 1 of the maintenance mode.
METAL Y adjustment [to step (8)]
(3) Observe the video output signal at the composite waveform monitor.
(4) Playback the multiburst signal portion (8:00 to 11:00) of the alignment tape CR5-1B or CR5-1B PS,
and adjust the level at specified frequency part by table below.
And check that levels at others are with specifications.
(DNW-A22: CR5-1B, DNW-A22P: CR5-1B PS)
n
As the Y output is overlapped the outputs of A and B channels on the composite waveform monitor,
adjust/check in each channel.
Adjustment points: A channel:
B channel:
Specifications (A and B channels): See the table below.
Frequency Specification for DNW-A22
0.5 MHz Reference: 100% {0 dB}
4.1 MHz Adjust : 94 (100 to 90)%
1 MHz Check : 100 (106 to 63)%
2 MHz Check : 100 (106 to 63)%
3 MHz Check : 100 (106 to 63)%
4.5 MHz Check : 80 (106 to 63)%
0.5 1
100%
DNW-A22
(5) Reset No.2 (C MUTE) of S1/TBC-23 (B-1) to OFF.
(6) Connect the video monitor to VIDEO OUTPUT COMPOSITE 1 connector.
(7) Playback the multiburst signal portion (8:00 to 11:00) of the alignment tape CR5-1B or CR5-1B PS,
and check that the playback picture on the video monitor has no flicker.
(DNW-A22: CR5-1B, DNW-A22P: CR5-1B PS)
(8) Reconnect the video monitor to VIDEO OUTPUT COMPOSITE 2 (SUPER) connector.
6-52
A32 : DM VR 1 : EQ1 METAL-Y-A
A32 : DM VR 1 : EQ1 METAL-Y-B
+0.5
{_0.5 dB}
_0.4
+0.5
{0 dB}
_4.0
+0.5
{0 dB}
_4.0
+0.5
{0 dB}
_4.0
+2.5
{_2.0 dB}
_2.0
2 3 4.1 4.5 [MHz]
Frequency Specification for DNW-A22P
2T BAR Reference: 100% {0 dB}
5 MHz Adjust : 91 (96 to 87)%
0.5 MHz Check : 100 (106 to 63)%
1 MHz Check : 100(106 to 63)%
2 MHz Check : 100 (106 to 63)%
4 MHz Check : 100 (106 to 63)%
5.5 MHz Check : 84 (106 to 63)%
2T BAR 0.5 1
100%
DNW-A22P
{_0.8 ± 0.4 dB}
+0.5
{0 dB}
_4.0
+0.5
{0 dB}
_4.0
+0.5
{0 dB}
_4.0
+0.5
{0 dB}
_4.0
+2.0
{_1.5 dB}
_2.5
2 4 5 5.5 [MHz]
DNW-A22/A22P