Sony GV-D1000E - Digital Video Cassette Recorder, Service Manual, Page: 98 / 134

5-24
GV-D1000/D1000E
3-6. AUDIO SYSTEM ADJUSTMENTS
[Connecting the measuring instruments for the audio]
Connect the audio system measuring instruments in addition to the
video system measuring instruments as shown in Fig. 5-3-11.
[Adjustment Procedure]
1) Playback level check
2) Overall level characteristics check
3) Overall distortion check
4) Overall noise level check
5) Overall separation check
1. Playback Level Check
Mode Playback
Signal Alignment tape:
For audio operation check
(XH5-3 (NTSC))
(XH5-3P (PAL))
Measurement Point AUDIO OUT jack LEFT or RIGHT
Measuring Instrument Audio level meter and frequency
counter
Specified Value 32 kHz mode: 1 kHz, +3.0 ± 2.0dBs
48 kHz mode: 1 kHz, +3.0 ± 2.0dBs
44.1 kHz mode:
The 7.35kHz signal level during EMP
OFF is +2.0 ± 2.0dBs.
The 7.35kHz signal level during EMP
ON is –6 ± 2 dB from the signal level
during EMP OFF.
Checking Method:
1) Check that the playback signal level is the specified value.
2. Overall Level Characteristics Check
Mode Recording and playback
Signal 400Hz, –7.5dBs signal: Audio
terminal left and right of AUDIO/
VIDEO INPUT jack
Measurement Point AUDIO OUT jack LEFT or RIGHT
Measuring Instrument Audio level meter
Specified Value –7.5 ± 3.0dBs
Checking Method:
1) Input the 400Hz, –7.5dBs signal in the audio terminal left and
right of AUDIO/VIDEO INPUT jack.
2) Record the signal.
3) Playback the recorded section.
4) Check that the 400Hz signal level is the specified value.
3. Overall Distortion Check
Mode Recording and playback
Signal 400Hz, –7.5dBs signal: Audio
terminal left and right of AUDIO/
VIDEO INPUT jack
Measurement Point AUDIO OUT jack LEFT or RIGHT
Measuring Instrument Audio distortion meter
Specified Value Below 0.4%
(200Hz to 6kHz BPF ON)
Checking Method:
1) Input the 400Hz, –7.5dBs signal in the audio terminal left and
right of AUDIO/VIDEO INPUT jack.
2) Record the signal.
3) Playback the recorded section.
4) Check that the distortion is the specified value.
Fig. 5-3-11.
VIDEO OUT
(75
Ω
)
Pattern generator
AUDIO/VIDEO
INPUT
Main Unit
Audio generator
Attenuator
600
Ω
600
Ω
: 270
Ω
(1-249-410-11) + 330
Ω
(1-249-411-11)
AUDIO
LEFT
(White)
AUDIO
RIGHT
(RED)
VIDEO
(Yellow)
Recording
L
R
AUDIO OUT
VIDEO OUT
Main unit
Monitor TV
47k
Ω
47k
Ω
47k
Ω
(1-249-437-11)
Audio level meter
or distortion meter
Playback