6-3
6-4 E
2-4.
A
UDIO SYSTEM ADJUSTMENTS
[Connection]
Fig. 6-2-4.
2-4-1.
Normal A
udio System Adjustment
•
Make adjustment in the SP mode, unless otherwise specified.
Use a normal
VHS cassette for an adjustment tape.
[Adjustment Sequence]
1.
A
CE Head Adjustment
2.
E-E Output Le
vel Chec
k
3.
Frequency Response Chec
k
1.
A
CE Head Adjustment
Ref
er to the ser
vice man
ual of
VHS MECHANICAL
ADJUSTMENT
VI
.
2.
E-E Output Le
vel Chec
k
Pur
pose:
Confirm that the output level against the reference input is within
the specification.
Mode
E-E
Signal
400 Hz, –7.5 dBs
Measurement point
Audio output terminal
Measurement equipment
Audio level meter
Specified value
–7.5 ± 2 dBs
Conf
irmation Method:
1)
Input a signal of 400 Hz, –7.5 dBs to
Audio Line Input.
2)
Confirm that the audio output level is –7.5 ± 2 dBs.
Audio
generator
Attenuator
600
Ω
47 k
Ω
VCR
Audio
level meter
AUDIO LINE OUT
AUDIO LINE IN
3.
Frequency Response Chec
k
Pur
pose:
Confirm that the frequency characteristic is within the specifica-
tion.
Mode
REC and PB (SP mode)
Signal
400 Hz, –17.5 dBs
7 kHz, –17.5 dBs
Measurement point
Audio output terminal
Measurement equipment
Audio level meter
Specified value
0 ± 3 dB
Note:
T
ape path adjustment must have been completed.
Conf
ir
mation Method:
1)
Supply a signal of 400 Hz, –17.5 dBs to
Audio Line Input.
2)
Connect the audio level meter to the
Audio Line Output.
3)
Adjust the attenuator so that the audio level meter will indi-
cate –17.5 dBs.
4)
Make recording in the SP mode.
5)
Set an audio line input signal to 7 kHz and make recording.
6)
Playback a recorded portion, and measure output levels at 400
Hz and 7 kHz.
7)
Confirm that the 7 kHz playback output level within a range
of the 400 Hz playback output level 0 ± 3 dB.
2-5.
P
A
R
TS ARRANGEMENT DIA
GRAM FOR ADJUSTMENTS
MA-370 BO
ARD
(CONDUCT
OR SIDE)
J562
VIDEO/AUDIO LINE
IN/OUT
CN270
RF SWP
41
Q605
Q607
+12V
+6V
SW5V
MTR12 V
BE
B
E
1
4
IC601
JS401
ADJ