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9

1. Clean the following parts with a denatured alcohol-moistened

swab :
record/playback heads

pinch rollers

erase head

rubber belts

capstan

idlers

2. Demagnetize the record/playback head with a head demagne-

tizer.

3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the

parts adjusted.

5. The adjustments should be performed with the rated power sup-

ply voltage unless otherwise noted.

Mode

Torque meter

FWD

Meter reading

FWD
back tension

REV

CQ-102C

CQ-102C

CQ-102RC

CQ-102RC

CQ-201B

CQ-403A

CQ-403R

28 to 71g • cm

(0.39 – 0.99 oz • inch)

1 to 7g • cm

(0.01 – 0.10 oz • inch)

1 to 7g • cm

(0.01 – 0.10 oz • inch)

28 to 71g • cm

(0.39 – 0.99 oz • inch)

1. Demagnetize the record/playback head with a head damagnetizer.

(Do not bring the head demagnetizer close to the erase head.)

2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the

parts adjusted.

4. The adjustments should be performed with the rated power sup-

ply voltage unless otherwise noted.

5. The adjustments should be performed in the order given in this

service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit adjust-
ment.)

6. The adjustments should be performed for both L-CH and R-ch.
7. Switches and controls should be set as follows unless otherwise

specified.

Tape

P-4-A100

WS-48B

P-4-L300

Signal

10 kHz, –10 dB

3 kHz, 0 dB

315 Hz, 0 dB

Used for

Azimuth Adjustment

Tape Speed Adjustment

Level Adjustment

Procedure :
1. Mode : Playback

REV
back tension

FF/REW

FWD tension

REV tension

100g or more

(3.53 oz or more)

100g or more

(3.53 oz or more)

56 to 122g • cm

(0.78 – 1.69 oz • inch)

+

–

set

MD OUT (JK301)

level meter

test tape
P-4-A100
(10kHz, –10dB)

10

2. Turn the adjustment screw and check output peaks. If the peaks

do not match for L-CH and R-CH, turn the adjustment screw so
that outputs match within 1 dB of peak.

4. After the adjustments, apply suitable locking compound to the

parts adjusted.

Procedure :
Mode : Playback

3. Mode : Playback

1. Insert the WS-48B into the deck, and playback.
2. Adjust the Control at the bottom hole of the motor (M901) so

that the frequency counter reading becomes 3000 ± 90 Hz.

Adjustment Location : MOTOR (M901)

oscilloscope

MD OUT (JK301)

set

MD OUT (JK301)

test tape
P-4-A100
(10kHz, –10dB)

L

R

Waveform of oscilloscope

good

wrong

in phase

45 

°

90 

°

135 

°

180 

°

L-CH
peak

R-CH
peak

screw
position

output
level

within
1dB

L-CH
peak

R-CH
peak

screw
position

within 1dB

+
–

MD OUT (JK301)

set

frequency counter

test tape
WS-48B
(3kHz, 0dB)

 REV side

FWD side

Adjustment screw

Remove the front panel(B)

claw

claw

level meter

MD OUT (JK301)

set

test tape
P-4-L300
(315Hz, 0dB)

Deck is VR703 (L-CH) and VR704 (R-CH)
so that adjustment within the following adjustment level.

Playback level: 301.5 to 338.3 mV (–8.2 to –7.2 dB) level dif-
ference between the channels: within ±0.5 dB

Adjustment Location : TAPE PREAMP board

W.RMS (JIS) less than 0.3%
(test tape: WS-48B)

Procedure :
Mode : Playback

Adjusting hole

11

2. Mode : Playback

2. Mode: Playback

Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the VR701 (L-
CH) and VR702 (R-CH) on the TAPE PREAMP board to repeat
steps 1 and 2.

Adjustment level : Playback output of 10kHz level diffrence

against 315Hz reference should be ±0.5 dB.

Adjustment Location : TAPE PREAMP board

Procedure :
1. Mode: Record

Confirm playback the signal recorded in step 1 become adjustment
level as follows.
If these levels do not adjustment level, adjustment the VR705 (L-
CH) and VR706 (R-CH) on the TAPE PREAMP board to repeat
steps 1 and 2.

Adjustment level :
Playback level : 47.2 to 53.0 mV (–24.3 to –23.3 dB)
Adjustment Location : TAPE PREAMP board

[TAPE PREAMP BOARD] (Component Side)

Procedure :
1. Mode : Record

level meter

MD OUT (JK301)

set

recorded
position

AF OSC

attenuator

600

Ω

set

MD IN (JK301)
1) 315Hz
2) 10kHz

blank tape
CS-123

50 mV (–23.8 dB)

}

AF OSC

attenuator

600

Ω

set

MD IN (JK301)
315Hz 50 mV (–23.8 dB)

blank tape
CS-123

level meter

MD OUT (JK301)

set

recorded
position

VR706

REC BIAS

R

VR705

REC BIAS

L

VR704

PB LEVEL

R

VR703

PB LEVEL

L

12

1. CD Block is basically constructed to operate without adjustment.

Therefore, check each item in order given.

2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M

Ω

 impedance.

4. Clean the object lens by an applicator with neutral detergent when

the signal level is low than specified value with the following
checks.

Procedure :
1. Connect the oscilloscope to test points TP (FE) and TP (VC).
2. Connect TP (FEI) and Ground, and TP (AGCCON) and Ground

of the BD board with lead wires.

3. Press the  

1/u  button to turn the set ON.

4. With the disc (YEDS-18) loaded, press the  

(  button and per-

form focus search. (Focus search will be performed in the same
way even while the disc table is pushed in and out.)

5. Check the symmetry and peak to peak level of the oscilloscope

waveform (S curve) at this time.

S-curve waveform

6. After check, remove the lead wire connected in step 2.

 • Try to measure several times to make sure than the ratio of

A : B or B : A is more than 10 : 7.

• Take sweep time as long as possible and light up the bright-

ness to obtain best waveform.

Procedure :
1. Connect oscilloscope to test point TP (RF) and TP (VC) on BD

board.

2. Connect TP (AGCCON) and Ground of the BD board with lead

wires.

3. Press the  

1/u  button to turn the set ON.

4. Put disc (YEDS-18) in and playback 5track.
5. Confirm that oscilloscope waveform is clear and check RF sig-

nal level is correct or not.

6. After check, remove the lead wire connected in step 2.

oscilloscope

BD board

TP (FE)
TP (VC)

+
–

symmetry

A

B

Within 4 

±

 1 Vp-p

oscilloscope

BD board

TP (RF)
TP (VC)

+
–

VOLT/DIV : 200mV
TIME/DIV : 500ns

level : 1.45 

±

 0.3 Vp-p

0V

Center of the waveform

B

Symmetry

A (DC voitage)

level : 1.3 

±

 0.6 Vp-p

oscilloscope

BD board

TP (TE)
TP (VC)

+
–

Clear RF signal waveform means that the shape “

◊

” can be

clearly distinguished at the center of the waveform.

RF signal waveform

Procedure:
1. Connect oscilloscope to test point TP (TE) and TP (VC) on BD

board.

2. Press the  

1/u  button to turn the unit ON.

3. Put disc (YEDS-18) in to play the number five track.
4. Press the  

(  button.

5. Check the level B of the oscilloscope's waveform and the A (DC

voltage) of the center of the Traverse waveform.
Confirm the following:

• A/B x 100 = less then ± 22 (%)
• B = 1.3 ± 0.6 Vp-p

1 track jump waveform

[ BD BOARD ] — SIDE B —

IC102

TP

(VC)

IC101

IC103

TP

(RF)

TP

(FE)

TP

(FEI)

TP

(AGCCON)

TP

(TE)