Sony DCR-TRV738E Service Manual page 123

3-5. AUDIO SYSTEM ADJUSTMENTS
Note1: Before performing the adjustments, check the data of page: 0,
address: 10 is "00". If not, set data: 00 to this address.
Note2: NTSC model: DCR-TRV740/TRV840
PAL model: DCR-TRV738E/TRV740E
[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. 5-3-10.
[Adjustment Procedure]
1) Hi8/Standard8 AFM BPF f
2) Hi8/Standard8 AFM 1.5MHz deviation adjustment
3) Hi8/Standard8 AFM 1.7MHz deviation adjustment
4) Digital8 playback level check
5) Overall level characteristics check
6) Overall distortion check
7) Overall noise level check
8) Overall separation check
Recording (Camera mode)
600 Ω
Audio oscillator
Attenuator
600 Ω: 270 Ω (1-249-410-11) + 330 Ω (1-249-411-11)
Playback
Main unit
Left (White)
AUDIO/
Right
VIDEO
(Red)
47k Ω (1-249-437-11)
Fig. 5-3-10.
adjustment
0
Main unit
MIC
Left
Right
TV monitor
Video (Yellow)
Audio level meter
47k Ω
or Distortion meter
47k Ω
DCR-TRV738E/TRV740/TRV740E/TRV840
1. Hi8/Standard8 AFM BPF f
(VC-278 board)
Sets the BPF passing frequency of IC5701 so that the AFM signal
can separate from the playback RF signal properly. If deviated. the
mono/stereo mode will be differentiated incorrectly, and noises and
distortions will increase during high volume playback.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note: The data of page: 0, address: 10 must be "00".
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Set the Hi-Fi SOUND switch (menu display) to "2".
3) Select page: C, address: 4E, change the data and minimize the
distortion rate.
4) Press the PAUSE button.
5) Set the Hi-Fi SOUND switch (menu display) to "1".
6) Select page: C, address: 4E, change the data and minimize the
distortion rate.
7) Press the PAUSE button.
8) Repeat steps 2) to 7) and set the data of address: 4E so that the
distortions rates when the Hi-Fi SOUND switch is set to "2"
and set to "1" respectively are almost the same and minimum.
9) Press the PAUSE button.
10) Select page: 0, address: 01, and set data: 00.
11) Set the Hi-Fi SOUND switch to "STEREO".
5-57
Adjustment
0
Playback
Hi8/Standard8 alignment tape:
For BPF adjustment
(WR5-11NS (NTSC), WR5-11CS (PAL))
AUDIO/VIDEO jack left or right
Distortion meter
C
4E
The Main and Sub channel distortion
rate should be almost the same (within
± 1%) and minimum.