Audio System Adjustments; Hi8/Standard 8 Mm Afm Bpf F; Adjustment (Vc-235 Board) - Sony DCR-TRV820 Service Manual

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. 5-3-18.
[Adjustment Procedure]

1) Hi8/standard 8 mm AFM BPF f

2) Hi8/standard 8 mm AFM 1.5 MHz deviation adjustment
3) Hi8/standard 8 mm AFM 1.7 MHz 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
In Recording
Pattern generator
Video output
(75 Ω)
Audio
600 Ω
oscillator
Attenuator
600 Ω (270 Ω (1-249-410-11) +330 Ω (1-249-411-11))
In Playback
Main unit
A/V jack
Audio (L)
Audio (R)
Video
Fig. 5-3-18
adjustment
0
Main unit
Video
A/V jack
Audio (L)
Audio (R)
Audio level meter or
distortion meter
47 k Ω
47 k Ω: 1-249-437-11
TV monitor
1. Hi8/standard 8 mm AFM BPF f
(VC-235 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
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: F, address: 7D, change the data and minimize the
distortion rate.
4) Press the PAUSE button of the adjustment remote commander.
5) Set the Hi-Fi sound switch (menu display) to "1".
6) Select page: F, address: 7D, change the data and minimize the
distortion rate.
7) Press the PAUSE button of the adjustment remote commander.
8) Repeat steps 2) to 7) and set the data of address: 7D 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 of the adjustment remote commander.
10) Select page: 0, address: 01, and set data: 00.
11) Set the Hi-Fi sound switch to "STEREO".
5-53
Adjustment
0
Playback
Hi8/standard 8 mm alignment tape:
For BPF adjustment
(WR5-11NS (NTSC))
(WR5-11CS (PAL))
Audio left or right terminal of A/V
jack
Distortion meter
F
7D
The Main and Sub channel distortion
rate should be almost the same
(within ± 1%) and minimum.