Marantz 2215 - Introduction to Marantz 2215 Service Manual; Service Notes and Unit Breakdown; AM Tuner Operation and Alignment

INTRODUCTION
This
service
manual
was
prepared
for
use
by
Authorized
Warranty
Stations
and
contains
service
information
for
Marantz
Model
2215
Stereophonic
Receiver.
Servicing
information
and
voltage
data
included
in
this
manual
are
intended
for
use
by
the
knowledgeable
and
experienced
technician
only.
All
instruction
should
be
read
carefully.
No
attempt
should
be
made
to
proceed
without
a
good
understanding
of
the
operation
in
the
receiver.
The
parts
list
furnish
information
by
which
replacement
part
may
be
ordered
from
the
Marantz
Company.
A
simple
description
is
included
for
parts
which
can
be
usually
be
obtained
through local suppliers.
1. Service Notes
As
can
be
seen
form
the
circuit
diagram
the
chassis
of
Model
2215
consists
of
the
following
units.
Each
unit
mounted
on
a
printed
circuit
board
is
described
within
the
square
enclosed
by
a
bold
dotted
line
on
the
circuit
diagram.
1.
FM
Front
End
&
AM
Tuner
..
0...
ee
eee
mounted
on
P.C,
Board,
P100
2.
FMIF
Amplifier
and
Detector
Unit
........-....5555-
mounted
on
P.C.
Board,
P200
3.
Muting
Control
and
Meter
Amplifier
Unit
.............
mounted
on
P.C.
Board,
P300
4.
MPX
Stereo
Decoding
Amplifier
..........2...00000-
mounted
on
P.C.
Board,
P400
5.
Phono
Amplifier...
2...
ee
eee
mounted
on
P.C.
Board,
P900
6.
Tone
Amplifier
cso
cae
ao
Fs
eT
O
Ee
Ee
eS
mounted
on
P.C.
Board,
P500
7.
Tone
Control
Volume
Unit...
0...
2.0002
eee
ee
eee
mounted
on
P.C.
Board,
P650
8.
Power
Amplifier...
2.0...
ce
ee
es
mounted
on
P.C.
Board,
P700
©:
Power
Supp
de!
Grseanin
gw
aan
aie
eiere
i
ee
ware
ka
ea
mounted
on
P.C.
Board,
P800
10.
Loudness,
Muting,
High
and
low
Filter
Switch
Unit
.......
mounted
on
P.C.
Board,
P600
2.
AM
Tuner
All
components
except
Tuning
capacitor
and
ferrite
bar
antenna
are
mounted
on
a
printed
circuit
board
P
100.
The
AM
signals
induced
in
a
ferrite
bar
antenna
are
applided
to
the
base
of
Mixer
transistor
H102
through
a
capacitor
of
C109,
while
the
local
oscillator
voltage
is
injected
to
the
emitter
of
H102
through
the
capacitor
C157.
Both
AM
signals
and
oscillating
voltage
are
mixed
at
the
base-emitter
junction
and
converted
into
455
KHz
intermediate
frequency.
The
resulting
IF
signal
is
applied
to
the
first
IF
transformer
F101
consisting
of
one
ceramic
filter
and
two
tuned
circuits.
The
output
of
F101
is
led
to
the
transistor
H103
which
in
turn
apply
its
output
to
the
transistor
of
next
stage
H104.
The
fully
amplified
IF
output
is
then
applied
to
the
diode
H107
to
detect
audible
signal
through
the
detector
transformer
L102.
The
detected
audio
signal
is
filtered
and
amplified
and
the
final
audio
output
is
obtained
from
the
collector
of
H105
and
applied:
one
to
the
tape out
jacks
through
monitor
switch
on
the
front
panel
and
the
other
to
the
function
rotary
switch.
The
DC
component
of
the
detected
IF
signal
is
used
as
a
AGC
voltage
to
control
emitter
current
of
H103
and
H102
through
the
resistor
R112
and
R106
respectively.
A
part
of
IF
signal
output
is
also
applied
to
the
diode
H108
through
a
capacitor
C123
and
rectified
to
obtain
DC
current
for
energizing
the
AM
signal
strength
meter
MOO1.