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– 9 –

Mode

Tension Meter

Meter Reading

Forward

CQ-403A

more than 60 g

Reverse

CQ-403R

(more than 2.12 oz)

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

swab:

playback head

pinch roller

rubber belt

capstan

idler

2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the power supply

voltage (14.4 V) unless otherwise noted.

Mode

Torque Meter

Meter Reading

Forward

CQ-102C

25 – 55 g•cm

(0.35 – 0.76 oz•inch)

Forward

CQ-102C

1.5 – 4 g•cm

Back Tension

(0.02 – 0.06 oz•inch)

Reverse

CQ-102RC

25 – 55 g•cm

(0.35 – 0.76 oz•inch)

Reverse

CQ-102RC

1.5 – 4 g•cm

Back Tension

(0.02 – 0.06 oz•inch)

FF, REW

CQ-201B

50 – 150 g•cm

(0.69 – 2.08 oz•inch)

0 dB= 0.775 V

1. The adjustments should be performed in the order given in

this service manual.

2. The adjustments should be performed for both L-CH and

R-CH.

Procedure:
1. Put the set into the FWD PB mode.

2. Turn the screw and check the output peak value.  Adjust the

screw so that the peak value in channels L and R coincides
within 2 dB.

3. Check the phase in the FWD PB mode.

Type

 Signal

 Used for

P-4-A063

6.3 kHz, –10 dB

head azimuth adjustment

WS-48A

3 kHz, 0 dB

tape speed adjustment

level 

meter

test tape 
P-4-A063
(6.3 kHz, –10 dB)

set

speaker out terminal

4 

Ω

+
–

screw
position

L-CH
peak

within
2 dB

output
level

L-CH
peak

R-CH
peak

within
2 dB

angle

R-CH
peak

test tape 
P-4-A063
(6.3 kHz, –10 dB)

L-CH

R-CH

speaker out terminal

oscilloscope

V

H

+ +

–

–

Screen pattern

in phase

good

wrong

45 

°

90 

°

135 

°

180 

°

4 

Ω

4 

Ω

set

– 10 –

4. Repeat the above adjustment for the REV PB mode.
5. Check that output level difference between FWD PB mode

and REV PB mode is within 4 dB.

Adjustment Location: PB head

Procedure:
1. Put the set into the FWD PB mode.
2. Adjust adjustment resistor for inside capstan motor so that the

reading on the speed checker or frequency counter becomes in
specification.

Specification: Constant speed

Adjustment Location: See page 11.

See the adjustment location from on page 11 for the
adjustment.

Speed checker

Frequency counter

–2 to +3%

2,940 to 3,090 Hz

The tuner section has no adjustment.

FWD 

REV 











adjustment 
screws

+

–

speed checker

or

frequency counter

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

speaker out terminal

set

4 

Ω

– 11 –

Tape Speed Adjustment

CN901

– SET UPPER VIEW –

– 12 –

1

IC1 

1

 (XIN)

2 Vp-p

222 ns

Note on Schematic Diagram:
• All capacitors are in µF unless otherwise noted.  pF: µµF

50 WV or less are not indicated except for electrolytics
and tantalums.

• All resistors are in 

Ω

 and 

1

/

4

 

W or less unless otherwise

specified.

•

¢

: internal component.

•

2

: nonflammable resistor.

•

C

: panel designation.

•

U

: B+ Line.

• Power voltage is dc 14.4V and fed with regulated dc power

supply from ACC and BATT cords.

• Voltages and waveforms are dc with respect to ground

under no-signal (detuned) conditions.
no mark : FM
(

) :  AM

[

] : TAPE PLAYBACK

• Voltages are taken with a VOM (Input impedance 10 M

Ω

).

Voltage variations may be noted due to normal produc-
tion tolerances.

• Waveforms are taken with a oscilloscope.

Voltage variations may be noted due to normal produc-
tion tolerances.

• Circled numbers refer to waveforms.
• Signal path.

F

: FM

f

: AM

E

: TAPE PLAYBACK

• X

: parts extracted from the component side.

• Y

: parts extracted from the conductor side.

•

¢

: internal component.

• b

: Pattern from the side which enables seeing.