Marantz 2240 - FM Alignment Procedure; Stereo Separation Alignment; Muting Circuit Alignment

a6 8: BP ats Be we 4
6.
Repeat the step 4 and 5 until no further adjustment is necessary.
Note: During tracking alignment reduce the signal generator output as necessary to avoid AGC
action.
11.3 AM Signal Strength Meter Alignment
Set an AM signal generator to 1000 KHz at 5 KuV, and adjust R178 so that the signal
strength meter may read 90% of the full scale.
12.
1.
2.
rs
FM ALIGNMENT PROCEDURE
Connect a FM signal generator to the FM ANTENNA terminals and a oscilloscope and an
audio distortion analyzer to the TAPE OUTPUT jacks on the rear panel.
Set the FM SG to 87 MHz and provide about 3 to 5uV. Place the tuning pointer at the low
frequency end by rotating the tuning knob and adjust the core of oscillator coi! L104 to
obtain maximum audio output.
Set the FM SG to 109 MHz and provide about 3 to 5uV output. Rotate the tuning knob and
place the tuning pointer at the high frequency end and adjust the trimming capacitor C106
for maximum output.
Repeat the step 2 and 3 until no further adjustment is necessary.
Set
the
FM
SG
to
90
MHz
and
tune
the
receiver
to
the
same
frequency.
Decrease
signal
generator
output
until
the
audio
output
level
decreases
with
the
decreasing
generator
output.
Adjust
the
antenna
coil
L101,
RF
coil
L102
and
L103
and
IF
transformer
L105
for
minimum
audio
distortion.
Set
the
FM
SG
to
106
MHz
and
tune
the
receiver
to
the
same
frequency.
Adjust
the
trimming
capacitor
C102,
C104
and
C105
for
minimum
distortion.
Repeat the step 5 and 6 until! no further adjustment is necessary.
Adjust
the
secondary
core
(upper)
of
discriminator
transformer
L201
so
that
the
center
tuning
meter
pointer
indicates
its
center
at
no
signal
applied.
Set
the
FM
SG
to
98
MHz
and
increase
its
output
level
1
KuV
and
tune
the
receiver
to
the
same
frequency
so
that
the
center
tuning
meter
pointer
indicates
its
center.
Adjust the primary core (lower) of L201 for minimum distortion.
Set the FM SG to 98 MHz at 100 KzV, and adjust R374 so that the signal strength meter
may read 90% of the full scale.
. STEREO SEPARATION ALIGNMENT
Set the FM SG to provide 1 KuV at 98 MHz. Tune the receiver to the same pee $0
that the center tuning meter pointer indicates its center.
Turn the FM SG modulation off (with the pilot signal turned off), connect a frequency
counter
to
test
point
J310,
and
adjust
R311
so
that
the
frequency
counter
may
precisely
read 19 KHz.
Modulate the FM SG with stereo composite signal consisting of only subchannel signal (of
course a pilot signal must be included).
Adjust the trimming resistor R301 for maximum and same separation in both channels.
.MUTING CIRCUIT ALIGNMENT
Connect a VTVM across the resistor R363 and adjust the resistor R363 until the meter read
0.75V DC at no signal.
Set
the
FM
SG
to
provide
1
KuV
at
98
MHz
and
tune
the
receiver
to
the
same
frequency
correctly.