NAD 300 User manual

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CONTENTS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
SPECIFICATIONS
DISASSEMB LY I NSTRUCTI ONS 7
DIAL STRINGING DETAIL
ALIGNMENT AND CHECK POINTS
ALIGNMENTPROCEDURES ....9-
CHANGING POWER LINE VOLTAGES
TROUBLESHOOTI NG
TUNER FRONT-END
OO36TUNERBOARD ...2O
5027 PRE-AMPLIFIER BOARD ..,.. 21
6038 MAIN AMPLIFIER BOARD
7105 SWITCH BOARD
7110 DOLBY NR BOARD
7118 DOLBY FM CALIBRATION BOARD
BO25 POWER SUPPLY BOARD ...... 25
9025 TONE AMPLIFIEB BOARD .... 26
ELECTRICAL PARTS LIST 27 - 36
M ISCE LLAN EOUS PARTS LIST
PAGE
3- 6
7
I
12
13
18
19
22
23
24
25
37
38
39
BLOCK DIAGRAM
INTERNAL VIEW OF INTEGRATED CIRCUIT
SCHEMATIC DIAGRAM SEPARATE SHEET
2

1. SPECIFICATIONS
4.
5.
6.
A. FM SECTION
1. FM Tuning Range
*Adjustment for tuning prohibited below 87.5 MHz
in West Germany
2. Dial Calibration Accuracy 90 & 106 MHz
98 MHz
IHF Sensitivity at 90, 98 & 106 MHz
Noise and Distortion: -30 dB
lmage Rejection at 98 MHz
lF Rejection at 90 MHz
AM Rejection at 98 MHz
at 30% AM & 100% FM Simultaneous Modulation,
100 - 20,000 pV Antenna lnput
Limiter Sensitivity
at - 1 dB Below Maximum Audio
Total Harmonic Distortion at 98 MHz TAPE OUT
(at 400 Hz lOOo/o Modulation, 1,000 pV lnput)
Spurious Response at 98 MHz
Antenna lnput: 3 pV
OSC 2nd 206.7 MHz
1/2lF 103.35 MHz
10. lF Bandwidth,6 dB down Antenna lnput: 100pV
1 1 . lF Bandwidth, 50 dB down Antenna lnput: 100 pV
12. Signal-to-Noise Ratio 100% Mod., 1 mV lnput
13. Capture Ratio 1,000 prV, MONO lnput
14. Output Voltage
Stereo and Mono, 4OO H2,100% Mod. TAPE-2 OUT
15. Alternate Channel Selectivity (lH F)
Antenna lnput: 100 pV
16. Muting Threshold
B. FM MPX SECTION
1. Stereo Separation at 98 MHz
(Antenna lnput: 1,000 pV) 100 Hz
1 kHz
10 kHz
Hl-BLEND on, at 1 kHz
2. Total Harmonic Distortion
at 98 MHz Stereo, 1 mV Antenna lnput 1 kHz and/or
500 Hz 100% Mod., at REC OUT
3. Automatic Stereo Threshold
4. Residual 19 kHz & 38 kHz at 98 MHz, 1 mV lnput
5. Stereo Frequency Response 40 - 10,000 Hz
6. 19 kHz Pilot Signal Dev. to Activate
7.
9.
NOMINAL LIMIT
*87.7-108
r 150
t'100
1.8
83
90
t 200
x2OO
2.8
73
75
0.8
60
B-20
1.2
5-16
45
t1
7
1.6
o.25
250
600
70
1.2
1.0
75
10
o.4
10
50
0.6
80
80
200
800
65
2
35
40
28
13
30
33
22
1 313
UN IT
MHz
kHz
kHz
pV
dB
dB
dB
pV
o/
/o
dB
dB
kHz
kHz
dB
dB
dB
pV
dB
dB
dB
dB
o/
/o
sV
dB
dB
o/
/o
F.

LIMIT
NOMINAL
W/Channel
o/
/o
o/
/o
dB
dB
535-1,605
400
4-10
60
32
45
0.15
+0.5
-2.O
310.5
200130
2.2tO.5
200t30
200t30/30t5
t1.2
525-1,650
200
6
80
40
50
C. AM SECTION
1. AM Tuning Range
2. Sensitivity (lHF)
at 600, '1,000, 1,4OO kHz, 400 H2,30% Mod.
3. Bandwidth 6 dB down
at 1,000 kHz with Antenna lnput of 500 pVlm
4. lmage Rejection at 1,400 kHz
5. lF Rejection at 600 kHz
6. AGC Figure of Merit Form 0.2 V/m, at 1,000 kHz
7. Total Harmonic Distortion
at 1,000 kHz 5,000 pYlm Antenna lnPut,
4OO H2,30% Mod., at REC OUT
8. Dial Calibration Accuracy 600 kHz
1,000 kHz
1,400 kHz
9. Output Voltage
1 kHz 30% Mod. 5 mV/m lnput at TAPE 2 OUT
10. Signal-to-'Noise Ratio
400 Hz 30% Mod. 50 mV/m lnPut
D. AUDIO SECTION
1. Output Power
0.3% THD, 2O Hz - 20 kHz, B ohms Load,
Both Channels Driven
2. Harmonic Distortion
at 1 kHz,8 ohms Load, 65Watts OutPut
3. lntermodulation Distortion
at2Y Output,4 ohms Load
4. Frequency Response
AUX 1 W Output, 8 ohms Load
20 Hz - 2O kH,z
5. lnput Sensitivity
at 1 kHz, for 25.3 Volt Output, B ohms Load
PHONO
AUX
Mrc
TAPE IN
6. Tape Recording OutPut Level
Front Panel Phono Jack/Rear Panel DIN Jack
at PHONO lnput: i mV
7. Phono lnput Equalization
50 - 15,000 Hz
4

NOMINAL LIMIT UNIT
8. Harmonic Distortion of EO Amplifier Section
at 1 kHz, 50 mV lnput
9. Overload Capability of EO Amplifier Section
at 1 kHz, 0.1% HD
10. Tone Control
BASS at 100 Hz
TREBLE at 10 kHz
11. Gain Difference of Left and Right Channels
at AUX and PHONO
12. High-Filter at7 kHz
13. Subsonic Filter at 40 Hz
14. Channel Separation on AUX lnput.
Opposite Channel : Shorted
i00 Hz
1 kHz
10 kHz
15. Signal-to-Noise Ratio (lnput Shorted)
PHONO
AUX
TAPE IN
Volume Minimum
16. LOUDNESS Compensation (-30 dB)
100 Hz
10 kHz
17. Harmonic Distortion of Pre-Amplifier Section
20 Hz - 20 k{z,2 Volt Output 50 Kohms Load
18. lnput Sensitivity of Pre-Amplifier Section
at 1 kHz, for 25.3 Volts Output, 8 ohms Load
E. DOLBY NR SECTION
1 . Output vs lnput at R EC Position
at2k1z,0 dB=30 mV
lnput Level 0 dB
-20 dB
_;3 3B
2. Output vs lnput at PLAY Position
at 5 kHz, 0 dB=30 mV
lnput Level 0 dB
-20 dB
-30 dB
3. Frequency Response of DOLBY FM
lnput=3O mV 5 kHz
10 kHz
0.035
240
t10
t10
-5
-3
o.o2
1
70
80
70
63
85
85
90
+8
+5
0
-15.7
-21.5
-31.1
0
-26.7
-40.3
+3
+5
0.08
200
t1Ot2
!1O!2
1.5
t2
t2
+8t2
+5t2
0.1
1!O.2
t2
-15.7t2
-21.5t2
-31.1t2
t2
-26.7!2
-40.3x2
+31 1
+5r 1
50
60
50
58
75
75
85
mV
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
o/
/o
V
dB
dB
dB
dB
dB
dB
dB
dB
dB

LIMIT
NOMINAL
F. GENERAL
1. Power Requirements
22OVAC,50 Hz (12O,24O VAC,50 Hz)
2. Dimensions
508(W) x 400(D) x 145(H) mm
3. Weisht 22 Ks.

1)
2l
2. DISASSEMBLY INSTRUCTIONS
Removing the metal enclosure from chassis. (Refer to Figure A)
Remove seven screws from top of the enclosure and four screws from both sides of the en-
closure, then pull off the enclosure f rom the chassis.
Removing the Front Panel. (Refer to Figure A)
a) Pull off all the control knobs except for PLAY CAL and REC LEVEL.
b) Remove three nuts from SELECTOR, SPEAKERS and DOLBY NR controls.
c) Remove three screws from top of the Front Panel and remove Front Panel.
Note: Numbers shown in circles correspond to Miscellaneous
Parts List on Page 37.
Figure A
'-V)
PIJLLEY
DIAL DRUM
(2 TURNS)
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3. DIAL STRINGING DETAIL
. PULLEY
Note: Tuning capacitor should be fully closed position
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4.ALIGNMENT AND CHECK POINTS
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5. ALIGNMENT PROCEDURES
Do not attempt alignment unless the following equipment is available.
EOUIPMENT DESCRIPTION
1. AM Signal Generator 5. Stereo Modulator 9. Frequency Counter
2. Oscilloscope
3. AC Voltmeter 6. Audio Generator
7. Distortion meter
4. FM Signal Generator 8. DC Voltmeter
AM IF & RF ALIGNMENT
Output of signal generator should be no higher than necessary to obtain an output reading.
Set SELECTOR switch 51 to AM.
[--00 cm
Loop Antenna
I
I
I
STEP SIGNAL
GENERATOR
COUPLING
Refer Fig.
S.IGNAL
GENERATOR
F REOUENCY
455 kHz
(400 Hz Mod.)
RECE IVER
DIAL
SETTI NG INDICATOR
AC Voltmeter
to TAPE OUT
jack.
ADJUSTMENT REMARKS
1
Point of non-
i nterference.
(on/about
600 kHz)
T401 (RF Coil)
Both sections
CF4O1
Adjust for
maximum
reading.
2Same as Step 1600 kHz
(400 Hz Mod.) 600 kHz Same as step 11401 (OSC Coil)
L451(ANT Coil)
Adjust for
maximum
read i ng.
3Same as Step 11400 kHz
(400 Hz Mod.) 1400 kHz Same as step 1
TC107
(OSC Trimmer)
TC105
(ANT Trimmer)
TC106
(RF Trimmer)
Adjust for
maximum
reading.
Repeat steps
(2) and (3)
4 Same as Step 11000 kHz
(400 Hz Mod.) 1000 kHz Same as step 1V R4O2 Adjust for
150 mV
Audio
Output
5Same as Step 1
1000 kHz
(400 Hz Mod.)
SG output
level 28mV/m 1000 kHz SIGNAL Meter VR4O1
Adjust for
maximum
read i ng
on SIGNAL
meter
AM/FM IF
L401, T401,
cF401
TUNER
FRONT END
TC105, TC106
TC107
Fis.1 AM ALIGNMENT CONNECTION

FM RF AND IF ALIGNMENT
Signa|generatoroutputshouldbenohigherthannecessarytoobtainanoutputreading.
Set Selector switch to FM'
Signal Generator deviation: 75 kHz
REMARKS
SIGNAL
GENERATOR
COUPLI NG
SIGNAL
GENERATOR
FREOUENCY
RECEIVER
DIAL
SETTING tNDTCATOR i AOlUsrn/lerur
Connect to FM
Antenna Terminal
through FM
DummY Antenna
(300sl) Fig' 2
90 MHz
(400 Hz. Mod.)
Adjust for
maximum
reading on
AC
Voltmeter
Same as Step 1
AC Voltmeter
connected to
TAPE OUT
jack
Same as Step 1
1104
(FM OSC Coil)
L1 01
(FM ANT Coil)
L102, L103
(FM RF Coil)
(oolofi.Yil'"0'' i '06 MHz
TC104
(FM OSC
Trimmer)
TC101
(FM ANT
Trimmer)
TC102, TC103
(FM RF
Trimmer)
Adjust for
maximum
reading
Repeat steps 1 & 2 until no further improvement is possible'
T101 (FM IFT)
Same as Step 1
DC Voltmeter:
connect
between BASE
of TR305 and
Ground
T2O1 TOP
(DISCRIMI-
NATOR)
Adjust for
maximum
reading
90 MHz
(4OO Hz, Mod.)
Same as Step 1
Adjust for
0V on DC
Voltmeter
90 MHz
(400 Hz, Mod.)
Same as Step 1
Adjust for
minimum
distortion
r*o3o-1il'"a., oo uu'
Distortion
Meter
connected to
TAPE OUT
jack
T201 Bottom
Same as Step 1
Adjust for
maximum
read i ng
9BMHz I L
!4^00 Hz, Mod.) i n, ,r, I signrr Meter
SG output
level: 1 V
Same as Step 1
Same as Step 1
Adjust for
60 mV read-
ing on AC
Voltmeter
AC Voltmeter
connected to
PIN 2 (or 9) of I vnzgta(or b)
7110 DOLBY
NR BOARD
98 MHz
(400 Hz, Mod.)
Fig.2 FM DUMMY ANTENNA
FM Dummy Antenna to 300o
antenna terminal of Receiver. Zin = 5012 (75o)
10
125c} (112.50)