Hitachi VT-S390E Wartungsanleitung Seite 27

3. AUDIO CIRCUIT ADJUSTMENTS
3-1. Carrier Frequency Adjustment
| - Hi-Fi audio is not played back.
Test Equipment
- TP501 (when adjusting | - Non-signal recording
RT501L)
¢ TP502 (when adjusting
RT501R)
+ Frequency counter
> RT501R (R-CH)
° e
Adjustment Procedure
1) RT501L : The frequency counter reads
1400kHz+1kHz at TP501.
2) RT501R : The frequency counter reads
1800kHz+1kHz at TP502.
3-2. Audio Bias Level adjustment
Purpose
of adjustment
and fault occurring
if incomplete
- Bias too Low: Sound tends to be
Test Equipment/Jigs
|
| distorted.
+ VIVM
State of VCR Adjustment Point
1 (BIA
+ Non-signal recording + RT401
- Blank tape
Adjustment Procedure
RT401: The VIVM reads 3. lmVrms+0. lmVrms.
4. TIMER CIRCUIT ADJUSTMENT
4-1. Level Meter Adjustment
correctly. |
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5) Set the AUDIO LEVEL (REC Volume) controls to
minimum and check that the -40dB. segments of
the level meter do not light.
6) If the above cannot be confirmed, perform
readjustment and then check IC702 (EAROM).
Adjustment Procedure
1) Connect a VIVM to the AUDIO OUT-(L)
and (R)
|
|
jacks.
|
2) Connect a CR oscillator to the Front AUDIO IN
-() jack.
\
3) Adjust the audio output of the CR oscillator so!
the VIVM reads -4.3 to -5.3dBs.
(The frequency should be 1kHz.)
|
4) Press and hold the STOP button
(for more than |
1 second)
while simultaneously
holding both
TRACKING buttons (A/W)
of the remote control
|
depressed
and check
that the 0dB segments of
I
the level meter light.
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