XR-1800, XR-1803, XR-1804 - Sony Car Audio Service Manual (repair manual). Page 10

– 10 –

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

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

level 

meter

test tape 
P-4-A063
(6.3 kHz, –10 dB)

set

speaker out terminal

4 

Ω

+
–