DOWNLOAD Sony XR-1800 / XR-1803 / XR-1804 Service Manual ↓ Size: 2.41 MB | Pages: 34 in PDF or view online for FREE

– 9 –

A

1

Push an arrow 

A

 part.

2

Removal the cassette holder (x)
to direction of the arrow.

– 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

+
–

– 11 –

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 13.

See the adjustment location from on page 13 for the
adjustment.

Speed checker

Frequency counter

–2 to +3%

2,940 to 3,090 Hz

XR-1800 E model, a tuner section is no adjustment.

0 dB=1 µV

When the tuner unit is defective, replace it by a new one be-
cause its internal block is difficult to repair.

Adjust the tuner section in the sequence shown below.

1. FM Auto Scan/Stop Level Adjustment
2. FM Noise Focus Adjustment
3. FM Stereo Separation Adjustment
4. MW Auto Scan/Stop Level Adjustment

[TUNER]

 button: FM 1

FREQUENCY SELECT switch: FM50 k (XR-1804 only)

Procedure:
1. Tune the set to 98.0 MHz.
2. Connect the digital voltmeter to TP2 (SD) on MAIN board.
3. Adjust RV2 on TU100 so that the reading on the digital volt-

meter changes point from low to high.

Adjustment Location: See page 13.

FWD 

REV 











adjustment 
screws

+

–

speed checker

or

frequency counter

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

speaker out terminal

set

4 

Ω

FM RF signal 

generator

dummy

antenna

Carrier frequency : 98.0 MHz
Output level

: 28 dB (25.1 

µ

V)

Mode

: mono

Modulation

: 1 kHz, 22.5 kHz deviation (30%)

antenna
jack (CN900)

set

50 

Ω

50 

Ω

0.1pF

+
–

TP2 (SD)

MAIN board







digital 
voltmeter

– 12 –

[TUNER]

 button: MW

FREQUENCY SELECT switch: MW 9 k (XR-1804 only)

Procedure:
1. Tune the set to 999 kHz
2. Connect the digital voltmeter to TP2 (SD) on MAIN board.
3. Adjust RV1 on TU100 so that the reading on the digital volt-

meter changes point from low to high.

Adjustment Location:  See page 13.

[TUNER]

 button: FM1

FREQUENCY SELECT switch: FM 50 k

Procedure:
1. Tune the 98.0 MHz.
2. The then output level is supposing that (A) dB.
3. Adjust with the volume RV3 on TU100 so that the output level

is (A) –32 dB then signal generator input set to –20 dB.

Adjustment Location: See page 13.

[TUNER]

 button: FM1

FREQUENCY SELECT switch : FM 50 k (XR-1804 only)

L-CH Stereo separation: A-B
R-CH Stereo separation: C-D
The separations of both channels should be equal.

Specification: Separation more than 26 dB

Adjustment Location: See page 13.

FM Stereo

Level meter

Level meter

signal generator

connection

reading (dB)

output channel

L-CH

L-CH

A

B

R-CH

L-CH

Adjust RV4 on TU100

for minimum reading.

R-CH

R-CH

C

D

L-CH

R-CH

Adjust RV4 on TU100

for minimum reading.

FM RF signal

generator

Carrier frequency : 98.0 MHz
Output level

: 60 dB (1 mV)

Mode

: mono

Modulation

: 1 kHz, 75 kHz deviation (100%)

0.01 

µ

F

set

antenna jack (CN900)

+
–

speaker out terminal

level meter

4 

Ω

FM RF signal

generator

Carrier frequency : 98.0 MHz
Output level

: 76 dB (6.3 mV)

Mode

: stereo

Modulation

: main: 1 kHz, 33.75 kHz deviation (45%)
  sub: 1 kHz, 33.75 kHz deviation (45%)
  19 kHz pilot: 7.5 kHz deviation (10%)

0.01 

µ

F

set

antenna jack (CN900)

+
–

speaker out terminal

level meter

4 

Ω 

AM RF signal

generator

Carrier frequency : 999 kHz
30% amplitude
modulation by
1 kHz signal
Output level

: 33 dB (44.7 

µ

V)

(50 

Ω

)

set

AM dummy antenna

30 

Ω

15 pF

65 pF

antenna jack (CN900)

+
–

TP2 (SD)

MAIN board







digital 
voltmeter