NAD C422, Service Manual

Page: 10 / 28

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ALIGNMENT PROCEDURES
FM/RDS SECTION
- FM mono: 1kHz, 75kHz devi., 60dB/µV
- FM stereo: 1kHz, 67.5kHz devi., 60dB/µV
Pilot signal 19kHz 7.5kHz devi.
OUTPUTS
- Connect the 47Kohm resistor unless otherwise noted.
Item
FM
IF/RF
Stereo
Distortion
Stereo
Separation
Mute
Level
Signal
output
Step
1
DC voltmeter L941
0±70mV
3
Distortion
analyzer
Distortion
analyzer
Oscilloscope
Oscilloscope
L942
R941
R956
Minimum
Minimum
2 AC voltmeter
IFT on the
front end
IFT on the
front end
Maximum
Maximum
separation
Distortion
Meter
Minimum
Connection
of instrument
Fig.1 –
–
Fig.2
Fig.2
Fig.1
Channel L
or R 1kHz
99.0MHz
1kHz 75kHz devi.
65dBf (60dB)
99.0MHz Ext.
mod. 65dBf
(60dB)
FM SG
output
Stereo mod-
ulator output Tuning
frequency
99.0MHz
99.0MHz
Channel L
or R 1kHz
99.0MHz Ext.
mod. 65dBf
(60dB)
99.0MHz Ext.
mod. 65dBf
(60dB)
RDS 2% MOD
99.0MHz 18dB
99.0MHz
99.0MHz
RDS – – – – Fig.3 99.0MHz
Output
indicator
Adjustment
point
Adjust
for
Remarks
FM MUTE/MODE
switch: ON/AUTO
Repeat the steps
1 to 3 until no fur-
ther adjustment is
necessary.
FM MUTE/MODE
switch: ON/AUTO
Don’t turn more
than ±180˚
Repeat stereo
distortion and
stereo separation
alignment until
THD at minimum
and separation at
maximum.
Decode
the RDS-
Program station
AM SECTION
AF Modulation: 400Hz, 30%
For AH Version
Step
1 –
2
3
530kHz
600kHz
990kHz
600kHz
400Hz 30% mod.
60dB/m
AM SG
output
Tuning
frequency
Output
indicator
Adjustment
point
600kHz
400Hz 30% mod.
60dB/m
AC
voltmeter
AC
voltmeter
Digital
DC
voltmeter
L972
OSC coil
on RF
block M971
RF coil
on RF
block M971
Adjust
for
1.35±0.2V
Maximum
Maximum
Step
1 –
2
3
522kHz
or
531kHz
603kHz
999kHz
600kHz
400Hz 30% mod.
60dB/m
AM SG
output
Tuning
frequency
Output
indicator
Adjustment
point
600kHz
400Hz 30% mod.
60dB/m
AC
voltmeter
AC
voltmeter
Digital
DC
voltmeter
L972
OSC coil
on RF
block M971
RF coil
on RF
block M971
Adjust
for
1.3±0.2V (522kHz)
1.35±0.2V (531kHz)
Maximum
Maximum
For C Version