Read Sony CHC-TB10 / CHC-TB20 / HCD-TB20 Service Manual online
24
HCD-TB20
4.
After the adjustments, apply suitable locking compound to the
parts adjusted.
parts adjusted.
Adjustment Location: Record/Playback/Erase Head
Tape Speed Check
Note: Set the test mode using the following method and begin tape
speed adjustment.
Procedure:
With the power turned on, press the x button, ENTER button,
and CD 3 button simultaneously.
(The message “MD” is displayed while in the test mode.)
To exit the test mode, press the "/1 button.
With the power turned on, press the x button, ENTER button,
and CD 3 button simultaneously.
(The message “MD” is displayed while in the test mode.)
To exit the test mode, press the "/1 button.
1.
Insert the WS-48B into deck.
2.
Press the Y button of deck.
3.
Check the reading of frequency counter becomes 3000 ± 90 Hz.
Sample Value of Wow and flutter
W.RMS (JIS) less than 0.3%
(test tape: WS-48B)
(test tape: WS-48B)
3.
Mode: Playback
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
oscilloscope
set
Waveform of oscilloscope
in phase
45
°
90
°
135
°
180
°
good
wrong
Pin
6
(GND)
MAIN board
CN322
Pin
CN322
Pin
5
or TP42 (L-CH)
Pin
9
or TP46 (R-CH)
L
R
Record Bias Adjustment
Procedure:
INTRODUCTION
When set to the test mode performed in
When set to the test mode performed in
Tape Speed Adjustment
,
when the tape is rewound after recording, the “REC memory mode”
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to MD.
(After recording, turn the m/M knob without stopping will
return to the position where recording was started.)
which rewinds only the recorded portion and playback is set.
This “REC memory mode” is convenient for performing this
adjustment. During recording, the input signal FUNCTION will
automatically switch to MD.
(After recording, turn the m/M knob without stopping will
return to the position where recording was started.)
1.
Press FUNCTION button to select MD. (This step is not
necessary if the above test mode has already been set.)
necessary if the above test mode has already been set.)
2.
Insert a tape into deck, press the REC PAUSE/START button,
and then press the Y button to start recording.
and then press the Y button to start recording.
3.
Mode: Record
5.
Confirm playback the signal recorded in step 2 become
adjustment level as follows.
If these levels do not adjustment level, adjust the RV653 (L-CH)
and RV603 (R-CH) on the TC board to repeat steps 3 and 4.
adjustment level as follows.
If these levels do not adjustment level, adjust the RV653 (L-CH)
and RV603 (R-CH) on the TC board to repeat steps 3 and 4.
Adjustment level: The playback output of 10 kHz level difference
against 315 Hz reference should be 0 ± 0.5 dB.
[TC BOARD]
4.
Mode: Playback
recorded
position
position
level meter
set
MAIN board
CN322
Pin
CN322
Pin
5
or TP42 (L-CH)
Pin
9
or TP46 (R-ch)
AF OSC
MD IN
1) 315 Hz
2) 10 kHz
1) 315 Hz
2) 10 kHz
blank tape
CS-123
CS-123
set
attenuator
600
Ω
} 50 mV (–23.8 dB)
Adjustment Location:
[MAIN BOARD]
RV652
(L-CH)
RV602
(R-CH)
(R-CH)
RV653
(L-CH)
RV603
(R-CH)
(R-CH)
Record Level
Record Bias
CN322
TP42
TP46
1
11
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