Nad C-442 Service Manual

NAD

C 422

STEREO

AM/FM TUNER

C 422

STEREO

AM/FM TUNER

SERVICE MANUAL

- 2 -

SERVICE SAFETY PRECAUTIONS

1. Safety check out

(Only U.S.A. model) Before returning the product to the customer, make leakage current or resistance measurements to determine that exposed parts are acceptably insulated from the supply circuit.

Parts marked with the symbol are critical with regard to the risk of fire and electric shock. Replace only with parts recommended by the manufacturer.

CONTENTS

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PAGE

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

REAR PANEL / FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

DISASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

ADJUSTMENT POINTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

INSTRUMENT SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

ALIGNMENT PROCEDURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12

SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14

IC BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-17

ELECTRICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-23

EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

EXPLODED VIEW PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-26

PACKING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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SPECIFICATIONS

AM TUNER SECTION

Input level is expressed as the reading in open-circuit of 75-ohm source impedance signal generator

Usable Sensitivity (999/1000kHz) ≤30dBµ S/N Ratio (5mV in) ≥38dB THD (5mV in) ≤3% IF Rejection (450kHz) ≥36dB Image Rejection (F+2xIF) ≥28dB Selectivity ≥17dB Output 130 +/-20mV Loop Sensitivity (20dB S/N)

999/1000 kHz ≤66 dB 603/600 kHz ≤66 dB 1404/1400 kHz ≤66 dB

Frequency response (100 - 2.3 kHz, 5mV) ±6 dB

FM TUNER SECTION

*C *AH

Input level is expressed as the reading in open-circuit of 75-ohm source impedance signal generator Usable Sensitivity (98 MHz) ≤13 dBµ ≤13 dBµ Signal / Noise Ratio Mono ≥72 dB ≥72 dB

(60 dBµ, IHF wtd) Stereo ≥66 dB ≥66 dB Frequency Response (20 Hz - 15 kHz, 60 dBµ) 0±1.0 dB 0±1.0 dB Channel Separation (60 dBµ) 30 Hz ≥33 dB ≥33 dB

1 kHz ≥42 dB ≥42 dB 10 kHz ≥32 dB ≥32 dB

Alternate Channel Sensitivity

(40 dBµ, ±400 kHz) ≥60 dB ≥45 dB Capture Ratio (40 dBµ) ≤3 dB ≤3 dB AM Suppression

(60 dBµ, 100% Mod.FM, 30% Mod AM) ≥65 dB ≥65 dB Image Rejection (119.4 MHz) ≥85 dB ≥85 dB I.F. Rejection (10.7 MHz) ≥78 dB ≥78 dB Pilot Suppression (60 dBµ) ≥60 dB ≥60 dB THD (60 dBµ, L=R 75 kHz for AH, 40 kHz Dev for C)

Mono ≤0.25% ≤0.25% Stereo ≤0.35% ≤0.35%

Auto-Search sensitivity On ≥24 dBµ ≥24 dBµ

Off ≤15 dBµ ≤15 dBµ

RDS Decode Sensitivity ≤26 dBµ ≤26 dBµ

PHYSICAL

SPECIFICATIONS

Dimensions (Width x Height x Depth) 435 x 80 x 285 mm Net weight 4 kg (8.8 lbs) Shipping weight 5.1 kg (11.22 lbs)

- 4 -

REAR PANEL / FRONT PANEL

REAR PANEL

FRONT PANEL

1. FM ANTENNA

2. AM ANTENNA

3. OUTPUT

4. IR IN

5. 12V TRIGGER IN

6. AC LINE CORD

1. POWER ON / OFF

2. POWER STATUS INDICATOR

3. BLEND

4. MEMORY

5. FM MUTE / MODE

6. AM / FM

7. DISPLAY

8. PRESET / TUNE

9. DISPLAY AREA

10. PRESET / TUNE CONTROL

PRESET

PROGRAM

FM MUTE

BLEND

TUNED

FM ST

RDS

ANTENNA

IMPORTANT NOTES

1. Show the software version

Press “PRESET/TUNE” and “TUNE UP” ( ).

2. Light UP all the icon on the VFL

Press “PRESET/TUNE” and “TUNE DOWN” ( ).

3. CPU Resets

Press “PRESET/TUNE” and “TUNE DOWN” ( ) and any one key.

4. AM Step 10K/9K Change

Add D206: 10KHz / Delete D206: 9KHz.

ANTENNA

GND

' 2003 NAD C 422

RDS Stereo Tuner C 422

BLEND

OUTPUT

FM MUTE

/ MODE

MEMORY AM / FM DISPLAY

DELETE

PRESET / TUNE

IR IN

+12V TRIGGER

PROGRAM

FM MUTE

BLEND

TUNED

FM ST

PRESET

ANTENNA

RDS

PRESET / TUNE

34567

- 5 -

DISASSEMBLY INSTRUCTIONS

1. Remove machine screws M 4.0 x 6.0 ( 1 to 4 ) from the side panels.

Remove tapping screw 3.0 x 8.5 5 from the back panel.

Refer to Figure No.1.

Figure No.1

2. Pull both sides of the TOP COVER slightly outwards 6 and tilt approx. 35˚ and then remove

in the direction as indicated by the arrow 7 . Refer to Figure No.2.

Figure No.2.

- 6 -

B L O C K DIA G R AM

MUT ING

AC INP U T

DIODE

MAT R IX

12V T R IG G E R

IR IN

MP XIN

P O WE R

S UP PLY

-V P

VF D

+10V

+5V C P U

U9 01

LA1837

AM/FM IF

F R ONT E ND

E NV 172D3G 1

T UNE

U9 02

16 14

LC 72723M

M218

R E MOT E

R DS DE C O DE R

S T/MO , MU TE , S ME TE R

data

OS C /IF

F M

OS C /IF

19 18

out

LC 7218

U9 03

ce data clk R DS -C LK R DS -S IG R DS -DATA

P L L

2345 15

75 76 74

LC 866448B

U2 01

C P U

22- 12V TR IG GE R IN

6 -IR IN

(#1 )=Po wer On

(#1 )

(#2 )=Pr otec t ( Flas h 2H z)

(#1 )+(#2 )=S tandby

(#2 )

S E N S OR

VF D

U2 02

24C 08

AM LO OP ANT F M A NT OUT P UT

K E Y MAT R IX

Trigger IN

E E P R OM

WIR ING DIA G R AM

K E Y B O AR D

LE D B O AR D

MAIN B O AR D

TR AN S F O R ME R

WH ITE B LUE Y EL LO W

P O WE R S UP P LY B O AR D

- 7 -

- 8 -

ADJUSTMENT POINTS DIAGRAM

OSC RF

- 9 -

SIGNAL

GENERATOR

ANTENNA

TERMINAL

OUTPUT

TERMINAL

DISTORTION

METER

DISTORTION

METER

VOLTMETER

OSCILLOSCOPE

VOLTMETER

OSCILLOSCOPE

VOLTMETER

OSCILLOSCOPE

OUTPUT

TERMINAL

OUTPUT

TERMINAL

ANTENNA

TERMINAL

ANTENNA

TERMINAL

ANTENNA

TERMINAL

AM LOOP ANTENNA

(Accessory)

AM LOOP

ANTENNA

60cm

DIGITAL

MILLIVOLT-

METER

VT_J911

SIGNAL

GENERATOR

SIGNAL

GENERATOR

SIGNAL

GENERATOR

RDS

GENERATOR

STEREO

GENERATOR

P901

OUTPUT

TERMINAL

MILLIVOLT-

METER

UNIT

INSTRUMENT SETUP

1. FM MEASUREMENT

Fig. 1

Fig. 2

2. RDS MEASUREMENT

Fig. 3

3. AM MEASUREMENT

Fig. 4

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