Marantz 2110 - Fm Alignment Procedures; FM Frequency Range and Tracking Alignment; Muting Threshold Adjustment

5.
FM ALIGNMENT PROCEDURES
5.1 FM FREQUENCY RANGE AND TRACKING ALIGNMENT
1.
Connect an FM signal generator to the FM antenna
terminals and an oscilloscope and an audio distortion
analyzer to the OUTPUT jacks on the rear panel.
. Set the generator to 87.4 MHz and provide about 3 to
5 uv. Place the tuning pointer at the low frequency end
by rotating the tuning knob and adjust the pitch of
oscillator coil L105 to obtain maximum audio output.
. Set the generator to 109 MHz and provide about 3 to
5yuV. Rotate the tuning knob and place the tuning
pointer at the high frequency end and adjust the trim-
ming capacitor C121 for maximum output.
. Repeat steps 2 and 3 until! no further adjustment is
necessary.
. Set the generator to 90 MHz and tune the tuner to the
same frequency. Decrease signal generator output until
the audio output level decreases with the decreasing
generator output. Adjust the pitch of antenna coil L101
and RF coil L102 for maximum output.
.
Set
the
generator
to
106
MHz
and
tune
the
tuner
to
the
same frequency. Decrease the signal generator output
until the audio output level decreases with the decreas-
ing generator output. Adjust the trimming capacitors of
antenna and RF tuning circuits for maximum output.
. Repeat steps 5 and 6 until no further adjustment is
necessary.
For 110V Operation For 120V Operation
Figure 2. Vottage Conversion Chart
3
8.
Connect
the
center
tuning
meter
to
the
test
points
J136
and
J137.
Adjust
the
L201
so
that
the
tuning
meter
pointer
indicates
its
center.
Depress
the
SCOPE
DIS-
PLAY
TUNING
pushswitch.
Adjust
the
R227
until
the
tuning
bar
is
located
the
center
of
the
oscilloscope.
Set
the
FM
signal
generator
to
60dB
at
98
MHz
and
tune
the
tuner
to
the
same
frequency
in
the
vertical
trace
of
the
oscilloscope..
Adjust
the
L202
for
minimum
distor-
tion,
5.2 STEREO SEPARATION ALIGNMENT
1,
Set
the
FM
signal
generator
to
provide
1
kuV
at
98
MHz.
Tune
the
tuner
to
the
same
frequency
so
that
the
tuning
bar
is
located
the
center
of
the
oscilloscope.
Then
turn
off
the
modulation
of
the
generator,
connect
a
frequen-
cy
counter
to
test
point
J138
and
adjust
R304
so
that
the
frequency
counter
may
precisely
read
76
kHz.
.
Modulate
the
generator
with
stereo
composite
signal
consisting
of
only
L
or
R
channel
(of
course
a
pilot
sig-
nal
must
be
included).
.
Adjust
the
trimming
resistor
R336
for
maximum
and
same separation in both channels.
5.3 MUTING THRESHOLD ADJUSTMENT
Set
the
FM
signal
generator
output
to
provide
12.5
UV
(IHF)
at
98
MHz
and
tune
tuner
to
the
same
frequency.
Adjust
the
trimming
resistor
R212
for
the
threshold
level
of
12.5
uV.
(During
this
adjustment
turn
the
FM
MUTING
pushswitch
“‘on’’).
1,
For
220V
Operation
For
240V
Operation