Ir Audio Deviation Adjustment (Mi-27/28 Board) - Sony GV-A500 Service Manual

3. IR Audio Deviation Adjustment (MI-27/28 board)

Mode VTR recording
Signal Audio signal:
Video signal:
Measuring point AUDIO OUT L terminal and AUDIO
OUT R terminal of IR receiver jig
(Terminated at 47 kΩ)
Measuring instrument Audio level meter
Adjusting page F
Adjusting address 75
Specified value –7.5 ± 0.5 dBs
Connection of Equipment:
Connect the measuring devices as shown in the following figure,
and adjust.
Pattern generator
VIDEO OUT
Ω
(75 )
Audio oscillator
Attenuator
600
Adjusting method:
1) Set page: 0, address: 01, data: 01.
2) Connect the audio level meter to the AUDIO OUT L terminal
of the IR receiver jig.
3) Set page: 3, address: 09, data: 01 and press the PAUSE button
of the adjusting remote commander.
4) Change the data of page: F, address: 75, and set the audio signal
level to the specified value.
5) Press the PAUSE button of the adjusting remote commander.
6) Connect the audio level meter to the AUDIO OUT R terminal
of the IR receiver jig.
7) Check that the audio level is within the specified value. If
outside, repeat from step 2.
8) Set page: 3, address: 09, data: 00 and press the PAUSE button
of the adjusting remote commander.
9) Set page: 0, address: 01, data: 00.
400 Hz, –7.5 dBs: Left or right of
audio input/output terminal
Color bar signal: Video input/
output terminal
Ω
600
Ω Ω
(270 (1-249-410-11) + 330
Main unit
Video
L
Audio
R
Ω
(1-249-411-11))
Fig. 5-3-22.
5-35
IR receiver jig
AUDIO OUT
L R
Audio level meter
Ω
47k
Ω
47k (1-249-437-11)