Marantz 2220B - FM Alignment Procedures; FM Signal Alignment; Stereo Separation Alignment; Muting Threshold Adjustment

6.
Note:
During
tracking
alignment
reduce
the
signal
generator
output
as
necessary
to
avoid
AGC
action.
co NI
12.
Repeat procedures 4 and 5 until no further adjustment is necessary.
FM ALIGNMENT PROCEDURE
Connect
a
FM
signal
generator
to
the
FM
antenna
terminals
and
an
oscilloscope
and
an
audio
distortion
analyzer
to
the tape
output
jack
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.
Rotate
the
tuning
knob
and
place
the
tuning
pointer
at
the
high
frequency
end
and
adjust
the
trimming
capacitor
C118
for
maximum
output,
Repeat steps 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.
Decrease
the
signal
generator
output
until
the
audio
output
level
decreases
with
the
decreasing
generator
ouput.
Adjust
the
trimming
capacitors
of
ANTENNA
and
RF
tuning
circuits
for
minimum
distortion.
Repeat steps 5 and 6 until no further adjustment is necessary.
Connect
a
DC
VTVM
with
1
V
range
selected
to
the
resistor
R237
(inside)
and
adjust
the
secondary
core
(black)
of
discriminator
transformer
L201
so
that
no
voltage
reading
is
obtained
on
the
VTVM
at
no
signal.
Next
set
the
FM
SG
to
98
MHz
and
increase
the
output
level
1
KuV,
then
tune
the
receiver
to
the
same
frequency
so
that
no
deflection
is
obtained
on
the
VTVM.
Adjust
primary
core
(pink)
of
L201
for
minimum
distortion.
. STEREO SEPARATION ALIGNMENT
.
Set
the
FM
SG
to
provide
1
KuV
at
98
MHz.
Tune
the
receiver
to
the
same
frequency_so
that
the
center
tuning
meter
pointer
indicates
its
center.
Then
turn
off
the
modulation
of
the
FM
SG,
connect
a
frequency
counter
to
test
point
R312
(point
C)
and
adjust
R
304
so
that
the
frequency
counter
may
a
precisely
read
19
KHz.
Modulate
the
FM
SG
with
stereo
composite
signal
consisting
of
only
L
or
R
channel
(of
course
a
pilot
signal
must
be
included).
Adjust
the
trimming
resistor
R
303
for
maximum
and
same
separation
in
both
channels.
»-MUTING THRESHOLD ADJUSTMENT
.
Set
the
FM
SG
output
to
provide
12.5uV(!IHF)
at
98
MHz
and
tune
receiver
to
the
same
frequency.
Adjust
the
trimming
resistor
R
253
for
the
threshold
level
of
12.5uV.
(During
this
adjustment
turn
the
MUTING
pushswitch
“‘on’’.)
POWER AMPLIFIER ADJUSTMENT
Connect
a
VTVM
between
J712(+)
and
J718(—)
and
adjust
the
trimming
resistor
R733
until
the
VTVM
reads
20
mV
DC.
And
next,
connect
a
VTVM
between
J723
and
J722
(GROUND)
and
adjust
the
trimming
resistor
R711
until
the
VTVM
reads
0
mV
DC.
Do
over
again.
For
the
other
channel,
connect
the
VTVM
between
J713(+)
and
J719(—)
and
adjust
the
R734
for
the
same
reading,
and
connect
the
VTVM
between
J724
and
J722
and
adjust
the
R712
for
the
same
reading.
Do
over
again.
.
13.
POWER SUPPLY ADJUSTMENT
Connect
a
VTVM
between
J812(+)
and
J811(—)
and
adjust
R808
until
the
VTVM
reads
35.0 V under no signal condition.