Marantz ST500 User manual

SERVICE
MANUAL
Ay C4
LN

MARANTZ DESIGN AND SERVICE
Using superior design and selected high grade components, MARANTZ Company has created the ultimate in stereo sound.
Only original MARANTZ parts can insure that your MARANTZ product will continue to perform to the specifications for
which it is famous.
Parts for your MARANTZ stereo are generally available within 72 hours throughout the nation via a toll-free line to our
National Parts Depot in California. The sales professionals who take your call immediately refer to their own desk top com-
puter terminal and can quickly determine the availability and price information you require. If for some reason, your order
should exceed our available stock, we usually can instantly provide an alternate replacement part or current delivery infor-
mation. When the order is placed and confirmed, the computer simultaneously generates “hard copy” orders at the
distribution center. As hard copies come directly from the computer to the national parts depot, your requested stock is
assembled and prepared for shipment and placed on the first available carrier for delivery to you.
ORDERING PARTS
Phone orders will eliminate mail delays, and we encourage the use of this method. If you order by mail, use MARANTZ parts
order forms which are available from our National Parts Depot located at the following address:
SUPERSCOPE NATIONAL PARTS DEPARTMENT
20525 Nordhoff Street
Chatsworth, California 91311
Phone: [phone]
1-213-998-9333
The following information must be supplied to eliminate delays in processing your order:
. Complete address.
. Complete part numbers.
. Complete description of parts.
. Model number for which part is required (indicate MARANTZ).
. Account number (for account customers only).
OhWN =
Direct consumers will be provided with the current retail prive quotation on available parts in order to advise them of the cost
of the parts and shipping.
OVERSEAS PARTS ORDERING
Parts may also be ordered from the following overseas addresses:
CANADA AUSTRALIA JAPAN
Marantz Europe, S.A. Superscope (Australasia) Pty., Ltd. Marantz GmbH
3710 Nashua Drive 32 Cross Street (P.O. Box 604) 3622 Kamitsuruma
Mississauga Brookvale 2100 N.S.W. Sagamihara Shi
Ontario, Canada L4V1M5 Australia Kanagawa, Japan
EUROPE
Superscope Europe, S.A. Marantz France Marantz Audio U.K. Ltd. Superscope GmbH
Avenue Leopold Il, 2 Rue Louis Armand 9 London Road, 203 Max-Planck-Strasse 22
7120 Peronnes-Lez-Binche 92600 Asnieres Staines D-6072 Dreieich 1
Belgium Hauts-de-Seine Middlesex West Germany
France England
All of the above locations are fully equipped to take care of your total service needs. Because various countries have differing ?
configuration requirements, it is necessary that you contact the service facility in your particular country. In the event that
there is no service location listed for your country, please contact the nearest facility for the necessary assistance.
BRnem Been watz.
We sound better

TABLE OF CONTENTS
SECTION PAGE
De ANT RO DUC ON ies oie See A aw aac ae aan Sa aa a ard ae a OG AS Cw ea ae 1
2. PW. BOARDS scsi h cise ea hae g SRW ce he a See hs Seah OG ols Ge woe Wack eR ee 2
3. TEST EQUIPMENT REQUIRED FOR SERVICING ... 1... ccc ene re eens 2
4, TUNER ALIGNMENT PROCEDURES..... 1.2... cc cece cece cere e eee eee ete 2~5
5. VOLTAGE CONVERSION... 0... ccc cc eee eee ene eee eee eee eee e neta 6
6. FREQUENCY SYNTHESIZER RADIO TUNING SYSTEM ..... 0... . cece eee ee eee eens 7~17
7, DIAGRAM AND COMPONENT LOCATIONS .............. ccc cee ce cece nee eeeeeeeeenas 18 ~ 25
8. FUNCTIONAL BLOCK DIAGRAM ..... 1... 0. cc eee eee nee eeees 26
9, EXPLODED VIEW AND PARTS LIST... 1.2... ce cc ccc ete ee eee eee ee nees 27 ~ 32
1D ELECTRICAL PARTS LIST 63 ve sce eee ieee oie PREG eS i ca Ca hd VR VERE omer ea ae 33 ~ 37
11. TECHNICAL SPECIFICATIONS. ......... cece cee eee ete tenet eee nes 39, 40
12. SCHEMATIC DIAGRAM

MODEL ST500 AM/FM STEREOPHONIC TUNER
SFOS G00
1. INTRODUCTION
This
service
manual
was
prepared
for
use
by
Authorized
Warranty
Stations
and
contains
service
information
for
Marantz
Model
ST500
AM/FM
Stereophonic
Tuner.
Servicing
information
and
voltage
data
included
in
this
manual
are
intended
for
use
by
the
knowledgeable
and
experienced
technician
only.
All
instructions
should
be
read
carefully.
No
attempt
should
be
made
to
proceed
without
a
good
understanding
of
the
operations
in
the
tuner.
The
parts
list
furnishes
information
by
which
replacement
parts
may
be
ordered
from
the
Marantz
Company.
A
simple
description
is
included
for
parts
which
can
usually
be
obtained
through
local
suppliers.
NOTE ON SAFETY:
&
computer Sim tuner:
selector .
ee re Tartine SCaee
co
power
4
2. P.W. BOARDS
As can be seen from the circuit diagram, the chassis of
Model ST500 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 dia-
gram.
1. Tuner & Synthesizer . . . mounted on P.W. Board P100
2..Noise Amplifier....... mounted on P.W. Board PBOO
3. Display Ass’y........ mounted on P.W. Beard P900
4. DE-Emphasis Switch ... mounted on P.W. Board PCOO
5. Scan Step........... mounted on P.W. Board PC50
6. FUSC:) bcc eee eee mounted on P.W. Beard PPOO
7. Function Switch...... mounted on P.W. Beard PSOO
8. Mode Switch ........ mounted on P.W. Board PT00
9. Preset Switch........ mounted on P.W. Board PU0O
THE
PARTS
MARKED
WITH
A
ARE
IMPORTANT
PARTS
ON
THE
SAFETY.
PLEASE
USE
THE
PARTS
HAVING
THE
DESIGNATED PARTS NUMBERS WITHOUT FAIL.
FTZ REGULATION
Instruction for the use in the range other than specified in
FTZ codes.
Achtung fiir die Leute, die in dem Gebiet wohnen, wo die
FTZ-Bestimmungen vorherrschend sind.
Sollte des Geradt auch fiir Frequenzen auszerhab des in
den FTZ-Bestimmungen angegebenen Bereiches «mpfange-
bereit sein, bitten wir, den Bereich durch Nachzellen des
Kernes in der Oszillatorspule (in der Abbildung nit “FTZ”
gekennzeichnet) so zu korrigieren, dass er den Betimmun-
gen entspricht.

3.
TEST
EQUIPMENT
REQUIRED
FOR
SERVICING
This
table
lists
the
test
equipment
required
for
servicing
the
Model
ST500
Tuner.
Use
Signal source for AM alignment
[Trem |___ Manufacturer and Model No,
AM Signal Generator
Test
Loop
Use
with
AM
Signal
Generator
FM
Signal
Generator
Signal
source
for
FM
alignment
ane
St
e
ti
li
tand
MPX
Signal
Generator
Sound
Technology
Mode!
1000A
ereo
separation
alignment
and
trouble
shooting
Distortion
Analyzer
Distortion
measurements
Audio
Oscillator
‘|
Sound
Technology
Model
1700A
Sinewave
and
squarewave
signal
source
AC
VTVM
Voltage
measurements
(AC)
Tektronix Model T93 ;
Oscilloscope
isaac
pede
2
Waveform
analysis
and
trouble
shooting
Philips Model 3232
MPX Oscillator adjustment (VCO)
Trouble shooting
Frequency Counter
Circuit Tester
Fluke Model 8000 “‘Digital’’ Simpson
Model 313, Triplet Model 801
AC
Wattmeter
Simpson
Model
1379
Monitors
primary
power
to
tuner
Line
Voltmeter
Simpson
Model
1359
Monitors
potential
of
primary
power
to
tuner
. Superior Electronic Co., ‘ :
Variable
Autotransformer
Powerstat
Model
116B-10A
Adjusts
level
of
primary
power
to
tuner
DC
VTVM
Voltage
measurements
(DC)
4.
TUNER
ALIGNMENT
PROCEDURES
A
dummy
resistor
of
47
kohms
must
be
connected
across
the
tuner
output
terminals
before
alignment.
4.1
FM
Alignment
Procedures
(Selector
switch
in
the
“FM”
position,
mode/tuning
switch
in
the
Mono/Manual
Position.)
1. FM Local Oscillator Alignment
Indicator
Connection
Signal
Frequency
Set the Digital.
Readout Frequency to
Signal Source
Connection
Repeat steps 1 and 2
107.90 MHz C117 for 201V
DC voltmeter in
30V and 3V range
to J505
88.10 MHz L106 for 3.0)
3
|
;
|
F

2.
FM
RF
Alignment
Signal Source
Connection
Signal tndicator Set the Digital
Frequency Connection Readout Frequency
RF generator to
FM antenna
terminal through
matching network
(300 ohms, balanced)
Maintain RF level
below limit.
C101, C107, C110 for
106.10 MHz 106.10 MHz maximum output and
VTVM to Lor minimum distortion.
R channel output
(3102) L101, L102, L103 for
90.10 MHz 90.10 MHz maximum output and
minimum distortion.
Repeat steps 1 and 2.
RF generator to FM
antenna terminals
through matching
network (300 ohms,
balanced) Maintain
RF fevel below limit.
RF generator 1mV
output to FM
antenna terminals
through matching
network.
(300 ohm, balanced)
RF generator 1mV
output to FM
antenna terminals
through matching
network.
(300 ohms, balanced)
RF generator 1mV
output to FM
7 antenna terminals
through matching
network.
(300 ohms, balanced)
VTVM to LorR
98.10 MHz channel output 98.10 MHz
(J102)
L105 for maximum
output and minimum
distortion.
“0” center meter
or DG current
98.10 MHz meter in 100uA 98.10 MHz
range between
J201 and J202
L202 primary core so
that the meter indicates
its center or may read
“Q",
{F Band switch "“Wide’’.
202 secondary core
for minimum distortion.
IF Band switch “Narrow”.
L201 core for minimum
distortion.
Distortion meter
to L or R channel 98.10 MHz
output (J102)
98.10 MHz
RTO1 so that signal
strength Led may
light 5 points.
98.10 MHz 98.10 MHz
ee
RF generator to FM
antenna terminals
through matching
network (300 ohms,
balanced) with the RF
signal level of that
the sigral strength
LED may light 3 points
.at IF band switch
“Wide"’.
1F Band switch “Narrow”.
R215 so that signal
strength Led may
light 3 points.
98.10 MHz 98.10 MHz

4.2
Muting
Circuit
Alignment
~
(FM
stopping
level
of
scanning.
FM
stereo
indicator
threshold
level.)
Signal Source
Connection
Signal
Frequency
Indicator
Connection
Set the Digital
Readout Frequency
Adjust:
RF generator 12.5uV
output to FM antenna
terminal through
matching network
(300 ohm, balanced)
98.10 MHz
4.3
Multiplex
Alignment
Procedures
(Selector
switch
in
the
“FM”
position.
Mode/Tuning
switch
in
the
Stereo/Auto
position.)
Signal Source
Connection
Signal
Frequency
VTVM to RorLl
channel output
(J102)
98.10 MHz
Set the Digital
Readout Frequency
indicator
Connection
R229 for 12.5uV
threshold level
(setting to Auto
position of “Mode”
switch)
Adjust:
RF generator to
FM antenna terminals
through matching
network (300 ohms,
balanced) with 1mV
FM stereo simulator
RF level and 100%
modulation (Pilot 9%)
RF generator to
FM antenna terminals
through matching
network (300 ohms,
balanced) with 1mV
FM stereo simulator
RF level and Pilot
9% modulation.
4.4
AM
Alignment
Procedures
No modulation
Stereo left
(1,000 Hz)
Stereo right
(1,000 Hz)
Pilot only
Frequency counter
to (J301)
VTVM to right
channel output
(J102)
98.10 MHz
VTVM to left
channel output
terminal (J102)
Repeat steps 2 and 3.
VTVM to right
and left channel
output
(J102)
(Selector
switch
in
the
“AM”
position.
Mode/Tuning
switch
in
the
Mono/Manual!
position.)
1.
AM
Local
Oscillator
Alignment
(Scan
step
selector
switch
(SC51)
in
the
“10
kHz”
position.)
Signal Source
Connection
Signal
Frequency
Set the Digital
Readout Frequency
Indicator
Connection
DC voltmeter in 1,610 kHz |
30V and 3V range
to (J505)
530 kHz
Repeat steps 1 and 2.
R303 so that
Frequency may precisely
read 76 kHz
1F Band switch ’’Wide”
RSO5.
IF Band switch ‘‘Narrow”
RS04.
For same separation in
‘both channels,
R306 so that
minimum output
should be the sarne in
both channels.
CA10 for 23V
LAO2 for 2.0V

2.
AM
IF
Alignment
Signal Source
Connection
Signal
Frequency
Indicator
Connection
Set the Digital
Readout Frequency
Adjust:
Sweep generator to
(RAOS)
3.
AMRF
Alignment
4.
AM
Stopping
Level
of
Scanning
(Mode/Tuning
switch
in
the
“Stereo/Auto”
Position.)
Signal Source
Connection
450 kHz marker
Signal
Frequency
Oscilloscope to
(JAO5)
Indicator
Connection
Quiet point on band
Set the Digital —
Readout Frequency
LAO3 & LAO4 for
maximum and
symmetric response
Adjust:
Apply the signal to
the AM bar antenna
from the RF generator
using the test loop.
As per the Figure 1.
1,400 kHz
600 kHz
VTVM to Lor
R channel output
(J102)
1,400 kHz
600 kHz |
CAO2 for
maximum output
L051 for
maximum output
Apply the signal to
the AM bar antenna
from the RF generator
using the test loop.
As per the Figure 1.
(with 3mV/m)
Signal Source
Connection
Repeat
steps
1
and
2
as
necessary
to
obtain
maximum
sensitivity.
1,000 kHz
Signal
Frequency
Indicator
Connection
1,000 kHz
Set the Digital
L Readout Frequency
RSO6 so that signal
strength LED may
light 4 points.
Apply the signal to
the AM bar antenna
from the RF generator
using the test loop.
As per the Figure 1.
(with
600uV/m)
1,000 kHz
=
VTVM to L
or R channel
output (J102)
Test Loop
60cm
1,000 kHz
AM Bar Antenna
Figure 1. Application of AM Signal
RA18 for 600;V
threshold level

5. VOLTAGE CONVERSION
e EUROPEAN MODEL ONLY
To convert the unit to a different power source voltage,
change the position as illustrated in the drawing below. CAUTION:
DISCONNECT POWER SUPPLY CORD FROM AC
OUTLET BEFORE CONVERTING VOLTAGE. DO
NOT DISASSEMBLE THE VOLTAGE SELECTOR
ABSOLUTELY.
(T) (A) Versions (N) Version — (P) Version
Figure 2. Voltage Conversion Chart

>
6.
FREQUENCY
SYNTHESIZER
RADIO
TUNING
SYSTEM
[1]
Construction
of
Synthesizer
System
This
frequency
synthesizer
is
composed
of
a
microcomputer
(MN1400SJ),
PLL
LS!
(MN6142),
CMOS
RAM
(MN1203),
prescaler
(uPB551C),
low
pass
filter,
crystals
and
fluorescent
indicating
tubes,
as
shown
in
Figure
1.
PLL
MN 6142
PRESCALER
yPBSSIC
MICROCOMPUTER
MN 14008J
CMOS RAM
MN 1203
INDICATOR
KEY BOARD
Figure 1
[2]
Microcomputer
MN1400SJ
[2]-1.
Terminal
Connections
[2]-2.
Block
Diagram
TOP VIEW
INSTRUCTION PLA rE)
STACK
2 LEVEL
t
2
3
4
5
6
7
8
9
J
Im
eof
MN 1400 SJ
g
Figure 2
C: COINCIDENCE DETECTOR G: GATE L: LATCH S: SYNCHRONIZING CIRCUIT
Figure 3