Marantz 105-B Service Manual

SERVICE

MANUAL

..........

....

";;i//L

TABLE

OF CONTENTS

SECTION PAGE
Introduction
AM

Tuner.

FM

Tuner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

AM

Alignment Procedure

FM

Alignment Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test Equipment Required
Parts List
Technical Specifications

...............................................................

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.....................................................

for

Servicing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.........

.

....................................................

....................................................

LIST

OF

ILLUSTRATIONS

1

..

1

..

1
3

..

3

..

4

13 ~ 17

.18

FIGURE PAGE

1.

Dial Stringing

2.

Front

Panel

3. Main

4.

5. Main

6.

7. FM,

Chassis

Rear

Panel Adjustment and Component Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chassis

FM/

AM Tuner Assembly P100 Component Locations. . . . . . . . . . . . . . . . . . . . . . . . . .

AM,

8. Power Supply Assembly P400 Component Locations

9. Schematic Diagram

10. Exploded Mechanical Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..........................................................

Adjustments and Component Locations. . . . . . . . . . . . . . . . . . . . . . . . . . .

Component Locations (Top View)

Component Locations

(Bottom

................................

View)

.............................

Mono and Muting Switch Assembly P300 Component Locations. . . . . . . . .

..........................

...................................................

..

5

..

6
6

..

7
7

..

8

..

8

" 8

9, 10

11, 12

TABLE

1.

Test Equipment Required

for

Servicing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

4

I

NTRODUCTI

This

service man

i

nf

ormation

Servicing in

k

no

wledgeable and experienced technician only.

at

tempt shou ld be m

t uner.

The

part
Marantz Com
th

roug h local suppliers .

The Mod

sam

e circu

supply

1.

H113
H113
base-emitter junctio
is applied

t

detect audible signal through the
and the final audio
th

c
H
stre

circuit.

AM

Tuner
All com ponents ex ce
T

he

AM

thro ugh a capacitor

through a capacitor C172. Bo

The o

ra

nsist

or

rou

gh

The DC c

urr

ent

of

124 through a capac

ng

th meter M001.

ON

ual w

as

prepared f

for

Marantz

for

mation and volta

lists furnish

pa

ny. A simple descrip

el 1058

itr

y as used in the Model

signals induced in a

to th

e f irst I F transformer L 116 consisting

utp

ut

of L11 6

of

next stage

the

funct ion switch.

om

ponent

H 104 through the resistor R 185. A part

Mod

el

ade

to proc

infor

is a tu

ner version

pt

ferri te bar antenna

of

C171,

n and converted

is led

Hl05. The full y ampli f ied IF

out

pu t

is

obtained

of

the det ected I F

itor

C1BO

or use

l 05B Stereophonic Tuner.

ge

data included in this manual

eed

without

mation by which replacement part may

tion is

of

the Marantz

201

ferrite

to

bar antenna

whil

e t

th

int

o 45 5KHz intermediate frequency. The resulting I F signal

the transistor H 1

det

ector transf

from

and rectified to obtain

by

Authoriz

a good understanding

included for parts which can

5 is employed except

are

mounted on a printed

he

local o

AM signa

ormer

pin terminal J118 and applied:

signal

ed

Warranty Stations and contains service

are

All

instruction

's

Model 2015 Tuner/Amplifier

are

appli ed

sci

llat

or

ls

and oscillating voltage

of

one ceramic

04

which in

output

L 117. The detected audio signal

is

used

as

of

I F signal

DC

should

the

audio

to

the

voltage

filter

turn

is

then applied

a AGC voltage

output

current

intended

be

read

of

the operation in the

be

be

usually

Amplifier,

circuit

base

is

is

for

board

of

converter transistor

injected

and

two

apply its

to

to

to

also applied

energizing the

for

use

by

carefully. No

ordered

to

are

the diode H123

the

from

be

obtained

and

almostthe

and power

Pl00.

the

emitter

mixed

tuned circuits.
output

control

is

filtered

output

emitter

to

the diode

AM

at

to

jacks

signal

the

the

of

the

the

to

1.1 Suggestions
Che

ck

for broken A M bar anten n
slowly
me
preceding final I F transf
check
deflect, check the local
osci
me
local osci llato r
VTVM

2.

next

same tim
transisto

and observe the

ter gives a

for

llator

asu

rin g oscillating voltage

and compare the measur

FM

Tuner
All components
FM signals induce d by a FM

These signals are then applied to t he FET RF

transi stor mixer

The

mixer

e.

r, t

for

AM

Tuner

AM

deflection

audio signals wit h the

tuning cap

convert its in

The H103

he

acitor

volt

age

is

are mou

Hl02 through a hi

inj ect ion voltage

trouble

signal

at sever

ormer

osc

illa

is

about 2

use

normal, check all voltage dist

nted on a printed circ

an

put

sign

is

a local oscillator

shooting

a,

next

streng

th

al frequencies received, no failure may exist in the

L 117. N

tor

ed

tenna are l

is abo

ext

tuning

a RF VTVM, no

values

al

meter deflected.

circuit. No rm

or

with

gh Q tuned

into 10.71V1

ut

40mV.

try

to

tune station

meter whether

connect a oscilloscope

al

oscillating voltage at the

3 volts, varying

circuit

ribution

those given in the schematic diagram.

uit

board P100.

ed

to

FM antenna coil L 101.

amplifier

circuit.

Hz

intermediate frequency and amplifies

and its

output

by

rotating fly-wheel

it

deflects

If

the signal strength meter does

with

tester gives correct indication. Ifthe

which in

is

or

not.

to

the pin terminal J118 and

tuning

in

injected

capacitor position. When

the

AM

turn

applies its

into

tuning

If

the signal strength

stages

at least

hot

end

of

circuits by using a

the

output

base

it

of

to

at the
mixer

knob

not

the

DC

the

1

---

.........:.:.

The 10.7

stage

of

I F

to

obtain

limiting

H 1

05

FET

2.1
The

Mode1105B.

The DC vo Itage

base
threshold

When

emitter
ampl

When

and can
transistor
the

threshold
The
The

on

and

high

characteristics,

output

RF

amplifier

Muting

muting

of H11

level).

H110

collector

ifier

H1 08.

the

not

keep H111

muting

DC voltage
off.

MHz

front

amplifier

is

and

0 and

input
turn

level are

and one stage

selectivity, a pair

rectified

to

decrease the gain

Auto-Stereo

circuit

turns

threshold

consisting

obta

i ned

turns

on,

resistance

signal

on the

turn

muted

obtained

end

output

improved

by the

Switching

by

on

it,

the

to

is

lower

H110,

off,

out.

level can be varied

is

is

led

of

sub I F

of

symmetrical

capture

diode

of

rectifi

if the sub I F

muting

near zero

thus

then

also used

H 115, H

with

Circuits

all solid-state electrical

ng

switch

than

the

the

no

to

the

next

IF section .

amplifier.

ratio

and good

116

increased signal strength.

the

su

b I F

output

transistor

ohm

and

predetermined

H110

keeps its

emitter

to

current

by

adjusting

make

Two

diode

and

output

is

greater than

H111

allowing

is

the

the

Auto-Stereo

limiters

AM

its

switching has

signal

level, the

turn

supplied

The

pieces

DC

emitter

trimming

of

ceramic

are also

suppression. A

output

from

predetermined

is

turned

current

DC

off

state and

to

the

resistor R 153.

switching

IF section consists

filters

are also used

employed

part

is

fed back

been

incorporated

the H109

on,

thus

path

output

this

H108

transistor H112

for

of

I F

to

the gate

is

app I ied

level

decreasing

to

the

obtained

makes the switch

and signals

of

five

the

best

amplifier

of

in the

to

the

(muting

the

Final

IF

is

small

below

turn

2.2

MPX

Stereo

A Non-equaliz ed
network
decoder
channel signals decoded

QJ)

de-emphasis
postamplifier
ampl

®

terminals

(j])

transistor
automatically
or

25~V.

of

Ie

(left

ified

(right

channel) and

on

the

Hl12,

off

in accordance

2.3 Suggestion

2.3.1

Symptom:

First

turn
slowly
frequencies received, the
When
The
the
distribution
the
circuits,

and observe

no

reading
normal
tuning

circuit

using high sensitive oscilloscope.

Decoding

audio
C148
consists

channel), respectively. These signals are

in

Jl14

MPX

local

capaCitor

and R161

of

networks

input

the

switching

for

on

in

the

diagram. When

to

pin ® (right

postamplifiers

pin ® (left

and

Jl15,

IC

Hl14

which

with

Trouble

No

FM Reception

the

power

the

is

obtained

oscillator

position.

FM

Front

Circuit

signal

a stereo decoder and postampl

by

eliminate

turns
between

FM

tuner

voltage

from

to

input

termin

the

stereo decoder H

undesira ble residual

channel) and

to

the

channel), and are

hence,

is

whether

Shoo

switch

in

through

connected

on

or

off

the

stereophonic

the

ting

of

and

TU NIN

circuits

the

meter, check FM local
is

one

If

the

End and I F

TUN

I NG

the

FM

detect

or

al

pin

CD

11

4,

pin

(j)

required

through R163

acc

FM signal strength

FM

try

G meter.

preceding t he

or

local

meter

level·

fu nction

ording

T

uner

to

tune FM

two

volts

oscillator

amplifier

deflects

then

to

and

If

(rms)

unit

is

applied

on

the

ifier

appear
passed
switching

(left

(approximately

passed

switches

to

the

the

incoming

monaural

stations

the

TUNING

discriminator

oscillator

at

voltage

and

but

through

MPX decoder IC

for

the output.

at

pin

through

signals and are

channel), respectively.

through

to

the

collector

operations. The H112

is

more

. R

otate

circuit,

the

tuning

is

normal, next

compare

no sound is

the

phase

Hl14.

The

right

@

(right

channel) and

the

low-pass

then

10

dB)

are delivered

C169 and

"OUTPUT"

of

the

autostereo

FM

signal

strength,

or

less

than

the

fly-wheel

cir

meter

cuit

them

deflect

may

usi

ng

capacitor, depending on

check all voltage

wit

h those shown in

obtained,

filters

delivered

The

C168

terminal.

approximately

tuning

have no fai lure.

a RF

VTVM.

check

adjuster

The

MPX

and

left
pin

and

to

signals

to

pin

to

pin

Pin

switch

thereby

turns

on

knob

at several

audio

2

2.3.2

Symptom:

First check the
output
beacon
signal, usi,

3.

3.1

1. Connect a sweep generator

2.

3.2

1. Set

2.

3. Repeat the step 1 and 2

4. Set the generator

5.

6. Repeat the step 4 and 5
Note :

modulated

is

turned

ng

AM

Alignment

AM

I F

point

@.

Rotate

symmetrical response.

pointer

Set

adjust the oscillator

output.

core

Set the generator

trimming

each

AM

Frequency Range and

AM

signal generator

at the

the

signal generator

of

AM

During

action.

No

Stereo Separation

"MONO"

by

a stereo

on

or

not.

If

an

oscilloscope.

Procedure

Alignment

core

of

I F transformer L

to

low

end.) and adjust the

to

trimmer

until

to

600

ferrite

capacitors

rod antenna
to

1400

of

Antenna (CA-1)

until

tracking alignment reduce the signal generator

switch

KHz and

is

in normal

modulator

not

turned

to

the

Tracking

525

KHz.

1650 KHz. Place the

on

no

further

for

KHz and tune the receiver

no

further

to

on, check

test

Alignmen

Turn

oscillator

the

oscillator

tune

maximum

for

out

the rear FM antenna terminals, and check the stereo

for

point

adjustment

adjustment

®

116

and L

t

the

tuning

coil L 115

tuning

tuning

the receiver

output.

maximum

position. Connect a FM R F signal generator

19 KHz

or

J 1 07 and

117

is

necessary.

to

output.

is

necessary.

pilot

signal and 38 KHz switching

an

alignment scope

for

maximum

capacitor

for

pointer

capacitor (CA-2)

the

to

maximum

in

same

the

same

output

fully

closed (place the

the

frequency and adjust a slug

frequency and adjust the

as

to

the test

height and

audio

output.

high frequency end and

for

maximum

necessary

to

flat

avoid

top

tuning

audio

AGC

FM

4.

2.

3. Set the FM

4. Repeat the step 2 and 3

5.

6. Set the

Alignment

1.

Connect a FM signal generator
distortion
Set the
frequency end
obtain

place the

Maximum

Set the FM
generator
Adjust
distortion.

capacitor

7.

Repeat the step 5 and 6

8. Connect a DC
secondary core (upper)

obtained on the
Next

to

Adjust

maximum

FIVI

maximum

the antenna coil

FM

set the FM

the

same

primary

Procedure

analyzer

SG

to
by

audio

SG

to

tuning

output.

output

CF-l,

reading on

pointer

SG

SG

to
CF-2

VTVM

VTVM

frequency

core

to

the tape

87.5

MHz and provide

rotating

output.

108.5

MHz

until

to

90

until

the audio

106 MHz and tune the receiver

for

until

with

at

SG

to

98

so

(bottom)

the

to

the FM antenna terminals and a oscilloscope and

output

the

and provide

at the high frequency end and adjust the

no

MHz and tune the receiver

L101,

minimum

no

±0.5

of

discriminator

no signal.

MHz

that

no
of

VTVM

jacks on the rear panel.

about 3 to 5 J.lV.

tuning

further

output

RF coil

further

volt

and increase the

connected

knob

about 3 to 5 J.lV

adjustment

level decreases

L102

distortion.

adjustment

range selected

deflection

L 107

for

and adjust the core

and IF

transformer L 107

is

obtained on the

minimum

to

the J109.

is

necessary.

to

to

the

is

necessary.

to

output

distortion,

Place the

output.

the

same

with

the decreasing generator

transformer

same

frequency.

the test

level

point
so

to 1 KJ.lV,

VTVM.

an

audio

tuning

of

Rotate the tuning

trimming

frequency . Decrease signal

L105

pointer

oscillator coil L 103

capacitor C187

for

Adjust

at

knob

minimum

the

trimming

the

output.

audio

® (J'120) and adjust the

that

no voltage reading

then tune the receiver

and adjust the L 108

for

low

to

and

for

is

the

..

_--

........... .

4.1

STEREO

1. Set the FM
Tune the receiver
point

2. Modulate
course a

Adjust
composite
maximum

Separation
SG

to

provide 1 K/-lV at

to

® gives no reading) .

the

FM

pilot

signal must

the core

of

signal consisting

and equal separation in

Alignment

the

SG

with

L 110

98

MHz

.

same

frequency

stereo composite signal consisting

be

included).

for

maximum

of L or

both

perfectely

audio

R channel

channels.

output,

only,

(so

then,

and adjust the

that

the

modulate

VTVM

of

connected

subchanged signal

the

FM

trimming

resistor R 161

SG

to

with

the test

only

(of

a stereo

for

Muting

4.2

1.

Set the FM

frequency.
Adjust
turn

5. Test

Table 1 lists the test

AM

Test

FM Signal Generator

I

Stereo Mod u

udio

A

Circuit

SG

the

trimming

the

MUTING

Equipment

Item

Signal Generator Signal

Loop

lator

Oscillator

I

Osc

ill

oscope

VTVM
Circuit

Tester

Alignment

output

to

resistor R153

pushswitch

Required

equipment

provide

for

Manufacturer

Less

Less

Weston Model CVO­than
tion

High sensitivity

zontal and vertical

With

25

/-lV

(lHF)

for

the threshold level

"on").

Servicing

required

than 0.3%

than 0.3 %

is

AC, DC, R F range Voltage measurements

0.02%
required

for

and Model No.

distortion

distortion

residual distor-

at

98

MHz and tune the receiver

of

25

/-lV

(during this

servicing the Model 105 B Tuner.

Use

source

ment
Used

with

AM

Signal source
ment

Stereo separation alignment
and

l00P,

with

DC

amplifiers

less

hori-

trouble

Sinewave and squarewaves
nal source

Waveform analysis and
ble Shooting, and ASO
ment

Trouble

shooting

Shooting

to

the

same

adjustment

for

Signal generator

for

align-

AM

FM align-

sig-

Trou-

align-

4

Table

1.

Test Equipment

Required

for

Servicing