NAD 4300 User manual

NAD SERVICE
__MANUAL
-a
MONITOR
SERIES
4300
STEREO
TUNER

C
NAD
4300
SERVICE
MANUAL
NOTE:
This manual covers
all
versions.
A:
U.S.A.
Al:
Canada
B:
U.K.
Bi
:
Austraha
C:
EUROPE
and
others
Cl:
W-Germany
TABLE
OF
CONTENTS
PAGE
LOCATION
MAP
2
SPECIFICATION
3
INTERNAL
VIEW
4
SUGGESTED INSTRUMENTATiON
HOOKUP
5
FM
ALIGNMENTS
6-9
AM
ALIGNMENTS
101l
WIRiNG DiAGRAM
12-13
P.C.B. LAYOUT
DIAGRAM
14—15
SCHEMATIC
DIAGRAM
16-17
EXPLODED
VIEW
PARTS
LIST
18-19
EXPLODED
VIEW
20
ELECTRICAL
PARTS
LIST
21-23

AM
Tuner Section
Usable
sensitivity.
Selectivity.
Image
rejection.
Mono, —30
dB
THD
÷
N:
Mono, 50
dB
S/N:
Stereo, 50
dB
S/N:
Mono, 60
dB
S/N:
Stereo, 60
dB
S/N:
Alternate
channel:
Adjacent
channel:
Mono:
Stereo:
Mono:
Stereo:
All
versions
except
USA.
50
sec.
de-emphasis
0.83
tV
1.3V
14.5,uV
3.2
tV
48
IN
250
jI
V/meter.
55
dB.
at
±
9
kHz
45
dB.
USA
version
only.
75
isec.
0.8.zV
1.OpV
l3pV
2.5
1 iV
42
iN
43.5
x
8.7
x
29.3
cm.
17.1
x3.4x11.51n.
4.55 Kg./lOIb.
5.75
Kg.112
lb.
10 oz.
50/60
Hz
at
110, 120,
220
or
240
VAC.
24W.
REAR
PANEL
1.
AM
Rod
Antenna
5.
Output Jacks.
2. AM
Antenna
Terminals.
6.
AC
Convenience
Outlet
(not
in
U.K.
model).
3.
FM
Antenna
Input. 7. AC
Line
Cord.
4.
Output
Level Control.
0
C
3
1
2
SPECI
FICATIONS
FM
Tuner
Section
Input
sensitivity
(300
2)
Capture ratio at
25,
45
&
65
dBf.
AM
rejection.
Selectivity
Image
rejection.
R.
F.
intermodulation.
I. F.
rejection.
SCA
rejection.
Pilot
suppression
(19
+
38
kHz).
THD at
100
%
modulation,
S/N
ratio,
A-weighted, 65
dBf.
Frequency
response,
15-
15
kHz.
Stereo separation
(FM
NR
off),
FRONT
PANEL
1.
Power.
2.
Station
Pre-sets.
3. Memory
Enter.
4.
Tuning
Display.
5.
FM
Stereo
Indicator.
6.
IF
Narrow
Indicator.
4
5
7
6
7.
AM/FM.
8.
I F
Narrow.
9.
FM
NR
Oft.
10.
Mono.
11. Tuning.
<2.1
dB.
>70
dB.
76
dB.
8dB.
110
dB.
73
dB.
102
dB.
80
dB.
69
dB.
1
kHz
0.08
%
0.07
%
84
dB.
77
dB.
100
Hz
-6
kHz
0.15%
0.35%
<2.1
dB.
>70
rIB.
76
dB.
8
dB.
110
dB.
73
dB.
102
dB.
80dB.
72
dB.
1kHz
lOOHz-6kHz
0.07%
0.15%
0.05
%
0.35
%
85
dB.
78
dB.
±
0.5
dB.
50
dB.
35
dB.
250
jI
V/meter.
()
60dB.
at
±
10
kHz
45
dB.
±
0.5
dB.
1
kHz:
50dB.
3OHz-l5kHz:
35dB.
NAD
tuNiNG
Monrior
Senes
Stereo
Tuner 4300
r
I
Eruese
ILJ.
III
OMSTENE’.)
FM
NARFOW OFF
.o
;
LL°_-----
IFNA000W
Physical
Specifications
Dimensions (width
x height
x
depth)
Net
weight
Shipping
weight
Power
requirements
1
1
2
3
4
56
78
910 11
()
3

INTERNAL
VIEW
4

0
()
FM ALIGNMENT
NECESSARY INSTRUMENTATION
• FM Generator
(less than
0.05%
THD.)
• Stereo
Modulator
(less
than
;0.05%
THD.,
more than
50dB Sep.)
• Audio
Generator
(not
necessay
if FM Generator
has
built-in
sweep,
e.g.,
SOUND
TECHNOLOGY
ST 1000A
and
ST
iO2OA)
•
AC VTVM’s
(or
one with a
LeftRight
switch)
•
THD
Analyzer (resolution
less than
0.1%)
• Oscilloscope
(5mV
or
better sensitivity,
X input
capability)
•
Frequncy
Counter
• VOM or
DMM (high
impedance,
must
read in
mV)
•
75 ohm
Dummy Antenna
IMPORTANT
1)
Before alignments commence,
release
IF
NARROW
and
MONO
switches
(out),
Switch FM NR
off
(in).
2)
IF FM
Generator
is not
synthesizer-type,
be sure
to check
its
frequency with
FREQ
counter
when adjusting
detector
and
multiplex
decoder circuits.
A. SYNTHESIZER FREQUENCY
1. Connect
Frequency
Counter between
TP-104
and ground.
2.
Tune to 98MHz
(No
RE
input
needed).
3. Adjust
C-201
so that
the local
oscillator frequency shown
by the frequency
counter reads
108.700MHz.
TOLERANCE:
108.700MHz
+/—2KHz
B. FRONT-END
ALIGNMENTS
Alignment
of the
front-end should
only be necessary
after repair
to the front-end
or
crystal oscillator
circuits.
a)
TUNING
VOLTAGE
It
is essential
to check
tuning voltage
before aligning
the
rest
of
front-end.
1.
Connect
DMM between
TP-105
and ground.
2.
Tune to
88MHz, and
adjust
L-6
if
the voltage
is incorrect.
TOLERANCE:
3.6V
+/—0.5V.
3. Tune
to 108MHz
and
confirm
that the voltage
is within
the
following
specification.
SPECIFICATION:
21-25V.
b)
TRACKING
1. Connect
FM Generator
(150KHz
sweep,
100V
output)
to 75ohm
antenna
input
and Detector Probe
to Pin 1
of
IC
102 with ground
to the tunershield.
2. Set
tuner to 106MHz,
entor
into Preset
8, and tune
the generator
so that curve
appears
on Oscilloscope.
3.
Adjust
C-2, C-9,
C-li
and
C-14 for maximum
curve
height
on
the oscilloscope
while
reducing
RF input
to keep
entire
curve on
display.
4. Set
tuner
to 90MHz,
enter
into Preset 1,
and
tune the
generator
so that curve
appears
on the oscilloscope.
5.
Adjust
L-1, L-2,
L-3
and L-4
for maximum
curve height.
6. Repeat
above
steps 2, 3,
4 and
5
(use
Preset
1 and
8) till
both frequencies
are at
maximum
curve
height.
SUGGESTED INSTRUMENTATION
HOOKUP
ó
o
OSCILLOSCOPE FM GENERATOR
AUDIO OSC
1
0 0
I
USE
ONL’? IF FM GENERATOR
WITH
BUILT-IN
SWEEP
UNAvAILABLE
I
WITH
BUILT-IN
SWEEP
lE: ST 1000A
DISTORTION METER
I\1
DISTORTION
OUTPUT
SCHEMATIC
DIAGRAM
OF
DETECTOR
PROBE
Cl
02
330p
00
•o
4.
00
Diodes
should be
point-contact
FROM
OUT
germanium;
Some
commonly
TUNER
C>’
TO scoc
available
types
are: 0A80
0A8
1
AA1
19
1N60
1
N34
1N22
PICTORIAL
DIAGRAM
OF
DETECTOR
PROBE
Ri
CENTER
LEAD
TOPINI
Cl
02
jjEEEE
SCOPE
Keep
leads
as
shortas
possible,
to
minimize
stray
signal
pickup.
AT
FRONTEND
5
6

C.
IF
ADJUSTMENT
1.
Set
tuner
to 98MHz
approx.
(the
tuner
must
be tuned
to
an unoccupied frequency),
and
tune FM
Generator
to
display
a
curve
on
Oscilloscope.
2.
Adjust
L-5 and
L-101
for maximum and
symmetrical
output
curve
on
the oscilloscope display,
using as
little
input as
possible.
D.
DETECTOR
ALIGNMENT
1. Disconnect Detector Probe
from
tuner
and Oscilloscope,
and connect
tuner
output
to the oscilloscope and
Distortion
Analyzer.
2.
Connect
DMM
across
TP-101
(—)
and
TP-102
(+).
3.
Tune to
98MHz
and
feed
1
mV
from
FM
Generator
(Modulate
1
KHz
100%)
to
75ohm
antenna
input.
4.
Adjust
L-102
Secondary for lowest
THD.
SPECIFICATION:
less
than
0.12%
(in
MONO).
5.
Adjust
L-102
Primary
for
OV
reading
on
DMM.
TOLERANCE:
+1—
5OmV.
6.
Repeat
above
steps
4 &5
till no
further
improvements.
E.
SIGNAL
METER
LEVEL
1. Tune
to 98MHz
and
feed
5V from
FM
Generator
to
75ohm
antenna
input.
2.
Adjust
R-127
so
that
the
second
LED
of signal
strength
indicator
is
just lit
up.
oc
CC)
00
6.
Check
and confirm
that
separation
under
wide
IF
bandwidth
is
within
the
following
specification.
SPECIFICATION:
more
than
50dB.
7.
Switch
IF
NARROW button
(in),
and
modulate
Left
(or
Right)
channel
only. Adjust
R-403
for
minimum
output
on
Right
(or
Left)
channel
VTVM
and
oscilloscope.
If
the
leak
outputs
on
opposite channels are
different,
readjust
R-403
so
that readings
become
same
in
both
left
and
right
channels.
8.
Check
separation under
narrow
IF bandwidth
and confirm
it is within
the
following
specification.
SPECIFICATION:
more
than
40dB.
H.
FM NR
CIRCUIT
Confirm
that
FM NR
button
is at OFF
position
(in),
at first.
1. Tune to
98MHz
and
feed
1 mV
with
100%
modulation
into
75ohm
antenna
input
and
set
reference
for
S/N
measurement.
With
reference
set,
cancell
the stereo
modulation and
leave
pilot
tone
only.
2. Adjust
the
attenuator
of FM
Generator
so
that
S/N
ratio
reads
50dB.
3.
Switch
FM
NR on,
and
adjust
R-148
so
that S/N
is
improved
by
8dB.
4.
Switch
FM
NR off,
and
adjust
attenuator of FM
Generator so that
S/N ratio
reads
60dB.
5.
Switch
FM
NR
on,
and
confirm
that
S/N
is
improved
by
approx.
2dB.
F.
STEREO
SWITCHING THRESHOLD
1.
Modulate
FM Generator 1 KHz
100%
Left
only,
pIus
19KHz
pilot
8-10%.
2.
Increase
FM
Generator
level
upwards
from
0
and
adjust
R-126
so
that stereo
light
turns
on
and
audio
outputs,
as
watched
on
VTVM’s
and Oscilloscope,
switches
to one
channel
only
at
5V
input
level.
TOLERANCE: +3V.
Note
that,
when
turning
input
level
down,
the
unit
will
switch
into
mono
at a
lower
level,
typically
3.5pV.
G.
STEREO
DISTORTION AND SEPARATION (WIDE/NARROW
IF
BANDWIDTH)
1.
Tune
to
98MHz
and
feed
1 mV
from
FM
Generator
to
75ohm
antenna
input.
2.
Modulate
Left
(or Right)
channel
only,
and adjust
L-5
and
L-101
slightly,
so that
the
distortion
on
Left
(or Right)
channel
becomes
minimum.
3.
Check
distortion
at
stereo
operation under
wide
IF
band-width.
SPECIFICATION:
less
than
0.12%,
stereo
L+R.
less
than
0.08%,
stereo
L
only.
less
than
0.08%,
stereo
R
only.
less
than
0.08%,
stereo
L—R.
4.
Next,
switch
IF NARROW
button
(in)
and
check
distortion
under
stereo
signal
input.
SPECIFICATION:
less
than 0.8%,
stereo
L
only.
less
than 0
8%
stereo
R
only
less
than
0.8%,
stereo
L-R.
5.
Reset
IF
bandwidth
to
wide
position
again
and
modulate
Left
channel
only. Adjust
R-141
for
minimum
output
on
Right
channel
VTVM
and
oscilloscope.
Next,
modulate
Right
channel
only
and
adjust
R-141
for
minimum
output
on
Left
channel
VTVM
and
oscilloscope.
If
the leak
outputs
on opposite channels
are
different,
readjust
R-141
so
that readings
become
same
in both
channels.
O
C.
O
0
0)
0
7
8

e
C9
L3
L6
L2 Cli
L51
LiOl
I
R403
I
1C102
I
(UNDER THE’
L
IF
B/W
P.C.P
C201
0
TP1O5
.‘
e
I
R127
TP1O1
TP1O2
L102s
R148
LlO2
Rl26
Rl41
TP404
9

AM ALIGNMENTS
OSCILLATOR.
1
Connect
DMM
to
TP-103
and
ground.
2
Tune to
1710
kHz.
Enter
into preset
1.
Adjust C-158
for
reading
of
31
±
0.5
VDC.
3
Tune
to
520
kHz.
Enter
into
preset
2.
Adjust L-105
for
reading of
1.8
±
0.1
VDC.
4
Repeat
above
steps
2
and
3
until
within
tolerances.
ANTENNA,
IF
1
Swing
antenna away
from
chassis.
2
Connect DC
voltmeter
to
centertap,
R-210
and
ground.
3
Tune to station
of
moderate strength,
near
600
kHz.
Enter
into
Preset 3.
Adjust L-901
for
maximum
reading on
meter
(Use
non-interactive
tool,
such
as
plastic
or
wooden
stick).
4
Adjust L-106
and
L-107
for
maximum
reading on
meter.
5
Tune to
a
station
of moderate
strength
near
1400
kHz.
Enter
into
Preset 4.
Adjust C-153
for
maximum
reading on
meter.
6
Repeat
above steps
3 and
5
until
no
further
improvement
is seen.
9
kHz,
10
kHz WHISTLE
FILTERS
1
Tune
to
a
quiet
spot
(a
clear
frequency).
2
Connect audio
oscillator
to
base,
Q-1
12
(isolate
with
0.1
- 1.0
iiF
capacitor).
3
Connect
AC
VTVM
(or
Scope) to
R-220
and
ground.
4
Set
audio
oscillator
to
10
kHz
(±
50
Hz)
1
V.
Adjust FL-104
for
minimum
meter
reading.
5 Set
audio
oscillator
to
9
kHz
(±
50
Hz)
1
V.
Adjust FL-105
for
minimum meter
reading.
D
SIGNAL
METER
1
Tune
to
1,000
kHz
and
feed 2.5
mV
to
the
antenna
terminals.
2
Adjust R-210 so
that
the fifth
LED
of
signal
strength
meter lights
up.
0
A
B
C
L901
L107
C
C
0
L106
Q112
FL1O4
FL1O5
R220
C153
C158
TP1O3
R210
in
11

(0
WIRING
DIAGRAM
(A
& Al
Versions, 120V
AC
with AC
outlet)
4:
I
(4
AM BAR ANTENNA
ANTENNA ThRMINAI.
RECEPTACLE
IF
B/w
SELECTOR
P.C.B(000IA)
POWER
TRANSFORMER
Jios
POWER
CORD
ROTARY SENSOR P.C.B
{NOOA)
VOLTAGE
SELECTOR
(ZOO4AI
POWER
INDICATOR
P.C.R
(M1O8A)
LED
DISPLAY
P.C.B(0013A)
PRESET SELECTOR P.C.B (SOS5A)
POWER SWITCH
12 13

____—
.
I - --
-
•i*
WIRING
DIAGRAM
(B,
Bi,
C
& Cl Versions, 220/240V
AC
less AC
outlet)
AM BAR
ANTENNA
ANtENNA
TERP.ENAL
• •
,
S S
•
IF B/w
SELECTOR
P.C.B(0001A)
POWER
TRANSFORMER
“Os
ROTARY SENSOR
P.C.B
(NOO1A)
VO4TAGE SELECTOR
IZOO4A)
I
POWER iNDICATOR PC.B
(M1ORA)
LED DISPLAY
PC.B(DOISA)
POWER
CORD
PRESET SELECTOR
P.C.B
)S085A)
POWER
SWITCH