Jvc Pc-70l User manual

JVC

SERVICE

MANUAL

Contents

Page

Safety

Precautions

..........

Jasbeqnntscechqeilnmbanasengaeinoeate

cs

2

Standard

Schematic

Diagram

of

PC-7O0LD

FGAtUleS

fiasco

ees

sins

tap

nccicy

nea

ee

3

(Amplifier

Circuit)

.......0...cccccccccceceeseeeeues

baliiemectinuic’

22

Specifications

:

3

P.C.

Board

Parts

and

Parts

List

(SEA

P.C.

Board)

.........

23

Name

of

Controls

and

Connection

Terminals

......

ite

dvedy

4

SEA

P.C.

Board

Parts

List

.......00...0c.ccccacsecseeceeueeeees

Attaching

and

Detaching

the

Speaker

...................0000

6

Tuner

P.C.

Board

Parts

.............ccccecccusescussceeueseeeenses

Location

of

Main

Parts

...

Tuner

P.C.

Board

Parts

List

Removal

of

Main

Parts

................0.ccccccecceeceeeseuseaeenes

Phono

P.C.

Board

Parts

....

Mechanism

Parts

............0ccccccsececcecenccecsueccaeeeneeeeees

Phono

P.C.

Board

Parts

List

How

to

Engage

Dial

Cord

...........0.0.ccccececcceeeeeeeeeeesees

Power/LED

P.C.

Board

Parts

...0........c0cccccccececeseeerneees

Main

Adjustment

.....................005

Power/LED

P.C.

Board

Parts

List

Mechanical

Adjustment

Power

Amp

P.C.

Board

Parts

List

.........

Cassette

Amplifier

Adjustment

............00..00cccce

evens

13

Enclosure

Assembly

and

Electrical

Parts

Tuner

Alignment

.........0.06...ccecceeneeceseneeereneneeeeeeeees

Enclosure

Assembly

and

Electrical

Parts

List

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

29

Wiring

Connections

.

Mechanical

Component

Parts

List

..........0...c..c0ceeeeee

Block

Diagram

Mechanical

Component

Parts

Integrated

Circuit

.........0....ccccecesccccaveeeeteeaeeeenes

sage

Exploded

View

and

Parts

List

for

Speaker

Standard

Schematic

Diagram

of

PC-7OL/LB

Speaker

System

Assembly

Parts

List

......0.....0....0605-

(Tuner

Circuit)

......cccccccceeccesceevecesecedsccaeeesecesieeeees

20

Packing

oi

icss.esccsccsbcssscusvsuene

Jin

tievactasSeectraulamiecrestess

se

37

Standard

Schematic

Diagram

of

PC-70LD

Packing

and

Packing

Parts

List

(Tuner

Circuit)

........00cc.ccccccccsecesecsccuuesseueusnes

insertion

ACCOSSOTIES

20.0...

c

cc

cecececceccueucecocuseeecsecaraeuens

Standard

Schematic

Diagram

of

PC-7OL/LB

(Amplifier

Circuit)

......0...0..00..cccccccuceecccneeusecusenesens

21

No.

1543

January

1984

PC-70

L/LB/LD/LS

2

Safety

Precautions

1.

The

design

of

this

product

contains

special

hardware.

5.

Leakage

current

check

Many

circuits

and

components

specially

for

safety

purposes.

For

continued

protection,

no

changes

should

be

made

to

the

original

design

unless

authorized

in

writing

by

the

manufacturer.

Replacement

parts

must

be

identical

to

those

used

in

the

original

circuits.

Service

should

be

per-

formed

by

qualified

personnel

only.

2.

Alterations

of

the

design

or

circuitry

of

the

product

should

not

be

made.

Any

design

alterations

or

additions

will

void

the

manufacturer’s

warranty

and

will

further

relieve

the

manufacturer

of

responsibility

for

personal

in-

jury

or

property

damage

resulting

therefrom.

3.

Many

electrical

and

mechanical

parts

in

the

product

have

special

safety-related

characteristics.

These

characteristics

are

often

not

evident

from

visual

inspec-

tion

nor

can

the

protection

afforded

by

them

necessarily

be

obtained

by

using

replacement

components

rated

for

higher

voltage,

wattage,

etc.

Replacement

parts

which

have

these

special

safety

characteristics

are

identified

in

the

parts

list

of

Service

manual.

Electrical

components

having

such

features

are

identified

by

(

A\

)

on

the

schematics

and

parts

list

in

Service

manual.

The

use

of

a

substitute

replacement

which

does

not

have

the

same

safety

characteristics

as

the

recommended

replacement

part

shown

in

the

parts

list

in

Service

manual

may

create

shock,

fire,

or

other

hazards.

4.

The

leads

in

the

products

are

routed

and

dressed

with

ties,

clamps,

tubings,

barriers

and/or

the

like

to

be

separated

from

live

parts,

high

temperature

part,

mov-

ing

parts

and/or

sharp

edges

for

the

prevention

of

elec-

tric

shock

and

fire

hazard.

When

service

is

required,

the

original

lead

routing

and

dress

should

be

observed,

and

they

should

be

confirmed

to

be

returned

to

normal,

after

re-assembling.

DC

motor

(Safety

for

electrical

shock

hazard)

After

re-assembling

the

product,

always

perform

an

isolation

check

on

the

exposed

metal

parts

of

the

Pro-

ducts

(antenna

terminals,

knobs,

metal

cabinet,

screw

heads,

earphone

jack,

control

shafts,

etc.)

to

be

sure

the

product

is

safe

to

operate

without

danger

of

electrical

shock.

Do

not

use

a

line

isolation

transformer

during

this

check.

e

Plug

the

AC

line

cord

directly

into

the

AC

outlet.

Us-

ing

a

‘‘Leakage

Current

Tester’’,

measure

the

leakage

current

from

each

exposed

metal

part

of

the

cabinet,

particularly

any

exposed

metal

part

having

a

return

path

to

the

chassis,

to

a

known

good

earth

ground

(water

pipe,

etc.).

Any

leakage

current

must

not

ex-

ceed

0.5

mA

AC

(r.m.s.).

e

Alternate

check

method

Plug

the

AC

line

cord

directly

into

the

AC

outlet.

Use

an

AC

voltmeter

having

1,000

ohms

per

volt

or

more

sensitivity

in

the

following

manner.

Connect

a

1500

2

10

W

resistor

paralleled

by

a

0.15

wF

AC-

type

capacitor

between

an

exposed

metal

part

and

a

known

good

earth

ground

(water

pipe,

etc.).

Measure

the

AC

voltage

across

the

resistor

with

the

AC

voltmeter.

Move

the

resistor

connection

to

each

exposed

metal

part,

particularly

any

exposed

metal

part

having

a

return

path

to

the

chassis,

and

measure

the

AC

voltage

across

the

resistor.

Now,

reverse

the

plug

in

the

AC

outlet

and

repeat

each

measurement.

Any

voltage

measured

must

not

exceed

0.75

V

AC

(r.m.s).

This

corresponds

to

0.5

mA

AC

(r.m.s).

AC

VOLTMETER

(Having

1000

ohms/volt,

or

more

sensitivity.)

ee

ot

4

0.15

pF

AC-TYPE

a

aor

cee

4

$a

hee

Place

this

probe

150092

10W

on

each

exposed

lo

metal

part.

Good

Earth

Ground

|

DC

Jack

AC

Jack

V.

Select

switch

Power

transformer

Fuse

(No.

1543)

Features

1.

Fashionable

mini

stereo

component

system

Fashionable

P-Compo

system

consisting

of

3

units

with

attachable/detachable

speakers.

2.

Total

output

of

10

W

(5

W+5

W)

max.

(3.2

ohms)

Music

power

of

12

W

(6

W+6

W)

(3.2

ohms)

“U-Turn’’

Auto-reverse

deck

for

recording/playback

with

soft-touch

machanism

PC-70

L/LB/LD/LS

Timer

start

mechanism

Two-position

tape

slect

switch

(METAL/NORMAL)}

5-LED

peak

indicators

5-elements

S.E.A.

Graphic

equalizer

PHONE/LINE

IN

jack

provided

for

the

connection

f

turntable

or

tape

deck.

3-way

power

supply

(AC,

batteries,

and

car

bat-

Metal

tape

compatibility

One-touch

recording

facility

Built-in

microphone

single

music

scan

facility

for

both

directions.

‘‘Under

license

of

Staar

S.A,

Brussels,

Belgium’’.

Specifications

Speakers

Frequency

ranges

Antennas

Track

system

Motors

Heads

Frequency

response

Wow

&

flutter

S/N

ratio

Rewind

time

Fast

forward

time

Power

output

S.E.A.

characteristics

:

10

cm

(4”)

(3.2

2)x

2

:FM

88—108

MHz

MW

540-1600

kHz

LW

150—350

kHz

SW

6—18

MHz

:

Telescopic

antenna

for

FM

&

SW

Ferrite

core

antenna

for

MW

&

LW

:

4-track

2-channel

stereo

:

Electronic

governor

DC

motor

for

capstan

&

reel

:

METAPERM

head

(for

recording/

playback)/2-Gap

Ferrite

head

(for

erasure)

combination

head

:

6O—

14,000

Hz

(with

metal

tape)

60—13,000

Hz

(with

normal

tape)

:

0.08%

(WRMS)

0.18%

(DIN

45500)

:

45

dB

:

Approx.

110

sec.

(C-60

cassette)

:

Approx.

110

sec.

(C-60

cassette)

:

Max.

10

W

(5

W

+

5

W)

Peak

music

power

of

12

W

(6

W

+

6

W)

S.E.A.

center

frequencies:

:

63

Hz/250

Hz/1kHz/4

kHz/16

kHz

S.E.A.

control

range:

+

12

dB

teries)

3.

Acoustic

suspension

speakers

¢

10-cm

full

range

speaker

x

2

¢

Speaker

connection

cords

with

mini-plug

Input

jacks

Output

jacks

Power

supply

Power

consumption

:

502(W)

x

149(H)

x

184(D)

mm

Dimensions

Weight

:

Mic

x

2

(0.78

(—62

dBV))

Matching

impedance:

200

2—2

kQ

2,

selectable

between

PHONO

(0.8

mV/47

kQ)

and

LINE

IN

(100

mV/47

kQ)

:

Speaker

x

2

(matching

impedance

3.2—8

Q)

Headphones

(matching

impedance

8—32

Q)

:DC

12

V

(8

“R14”

cells)

Car

battery

through

a

car

battery

adapter

AC

240/220/110

V,

50/60

Hz

16

Watt

(19-7/8”"

x

5-7/8”

x

7-1/4”)

including

knobs

:

Approx.

4.4

kg

(9.7

Ibs)

(without

batteries)

Approx.

4.9

kg

(10.8

Ibs)

(with

batteries)

Design

and

specifications

are

subject

to

change

without

notice

for

improvement.

(No.

1543)

3

PC-70

L/LB/LD/LS

|

Name

of

Controls

and

Connection

Terminals

=

Oe

Hh

oe

ey

.

Speakers

(Left,

Right)

2.

Indicators

OMAN

OaF

10.

11.

4

(No.

1543)

¢

DIRECTION

¢

POWER/BATT

e

LEVEL

¢

TUNE

¢

FM

STEREO

.

SOURCE

switch

(

—

)

PHONO/LINE

(

m

)

RADIO

.

TAPE

MONITOR

switch

.

EXT

MICROPHONE

jacks

.

FINE

TUNING

knob

for

SW

reception

.

Tape

COUNTER/reset

button

.

Dial

scale

.

MODE

switch

(

m

)

STEREO

(

=

)

MONO

BAND

switches

(FM/SW/MW/LW)

Built-in

microphone

(Monaural)

Fig.

1

12.

TUNING

knob

13.

VOLUME

controle

14.

Cassette

holder

15.

Cassette

operation

buttons

*

(Stop/Eject)

button

«<<

(Rewind)

button

©

(Record)

button

<«

PLAY

»

button

pe

(Fast

Forward)

button

ft!

Pause

button

16.

REVERSE

MODE

switch

>)

>

:

Continuous

play

:

Full

recording

or

playback

:

Single

recording

or

playback

17.

DIRECTION

switch

18.

TAPE

switch

19.

POWER

switch

20.

Headphones

jack

(PHONES)

(3.5

mm

dia.

stereo

miniplug)

21.

SEA

Graphic

Equalizer

controls

PC-70

L/LB/LD/LS

Ba

vod

ret

27

28

29

+30

31

32

33

34

Fig.

2-1

22.

Telescopic

antenna

for

FM

or

SW

reception

29.

VOLTAGE

SLECTOR

(240/220/110

V)

23.

Battery

compartment

cover

30.

AC

IN

jack

24.

GND

(ground)

terminal

31.12

V

DC

IN

jack

(

e-

)

25.

PHONO/LINE

IN

jacks

32.

BEAT

CUT

switch

26.

PHONO/LINE

IN

select

switch

33.

Speaker

cord

with

plug

(Left)

27.

Speaker

lock

lever

(Right)

34.

Speaker

lock

lever

(Left)

28.

Speaker

cord

with

plug

(Right)

PC-70LD/LS

only

Din

Jack

ae

2s

i

E

L

wae

a"

voUrice

sezcton

|

if

sf

(R)

~

ACN

IN320

(No.

1543)

5

PC-70

L/LB/LD/LS

Attaching

and

Detaching

the

Speaker

When

using

the

speaker

attached

to

the

receiver

When

using

the

speakers

attached

to

the

main

unit.

When

using

the

speakers

detached

from

the

main

unit.

1.

Hold

with

the

bottom

of

the

speaker

against

the

top

of

1.

Set

the

speaker

lock

lever

to

RELEASE.

the

main

unit

and

press

down

the

speaker

to

attach

it.

2.

Lift

the

speaker

to

detach from

the

main

unit.

Note:

Be

sure

to

set

the

speaker

lock

lever

to

e

A

better

stereo

effect

can

be

obtained

when

the

RELEASE.

speakers

are

placed

an

appropriate

distance

from

the

main

unit.

e

The

right

speaker

is

detached

in

the

same

way.

Speaker

slot

~=

RELEASE

Press

the

speaker

down

with

the

speaker

and

main

unit

aligned.

Speaker

cord

connections

As

illustrated,

connect

the

speaker

cord

plug

into

the

jack

and

fix

it

securely.

2.

Set

the

speaker

lock

lever

to

LOCK.

¢

The

right

speaker

is

attached

in

the

same

way.

6

(No.

1543)

PC-70

L/LB/LD/LS

Location

of

Main

Parts

Front

view

Tape

monitor

switch

Mode

switch

Source

switch

i i

a

Mic

jack

Fine

tuning

x

Band

selector

a

=

Ss

is

«

is

q

——

ies

=

Pointer

Counter

1

ee

Tuning

knob

Volume

Phones

jack

Mechanism

Ass’y

Power

switch

Tape

selector

Fig.

7

Rear

view

Ferrite

core

antenna

LED

P.C.

Board

Ass’y

Pointer

Tuner

P.C.

Board

Ass’y

<>

DC

motor

Phono.

P.C.

Board

Ass'y

PHONO/LINE

el)

Jack

BEAT

CUT

switch

DC

Jack

SEA

P.C.

Board

Ass‘y

Fuse

Power

transformer

AC

Jack

SP

Jack

Power

P.C.

Board

SP

Jack

V.

Select

switch

Ass'y

Fig.

8

(No.

1543)

7

PC-70

L/LB/LD/LS

Removal

of

Main

Parts

Fuse

replacement

1.

Remove

the

rear

panel

to

replace

the

fuse.

Rod

antenna

replacement

1.

Remove

the

screw

marked

‘‘ANT

SCREW”

and

replace

the

rod

antenna.

Removal

of

rear

panel

1.

Remove

the

eight

screws

(1)

~

GB)

from

the

bottom

and

rear

panels.

2.

Remove

the

antenna

and

battery

wires.

a

~

Soy?

7

:

i

’

As,

>

aa

ie

SNS

Sahn

RN

f

on

D-

Qoeprnae

va

x2

7

seSF3065N«5

&

Fig.

9

Removal

of

bottom

panel

1.

Remove

the

six

screws

(4)

~

6)

;

wy

(Remove

the

rear

panel

or

loosen

the

screws

@)

~

@)

before

this.)

ans

oe

‘

?

©

nS

Removal

of

top

panel

1.

Remove

the

bottom

panel.

2.

Pull

the

fine

tuning

knob

to

remove

it.

8

(No.

1543)

Removal

of

front

panel

1.

Remove

the

two

screws

@)

and

(8).

2.

Remove

the

lever

cap

and

volume

control

and

then

open

the

cassette

holder

to

remove

it.

Note:

When

reassembling,

set

the

reverse

mode

switch

to

[==]

or{c).

Removal

of

tuner

board

1.

Remove

the

two

screws

Q)

and

(0)

;

2.

Remove

the

connector

wires

4P

and

6P,

then

remove

the

connectors

from

CN101

of

the

amplifier

board.

Note:

When

reassembling

the

unit,

turn

the

dial

drums

and

variable

capacitors

fully

clockwise.

Removal

of

power

transformer

1.

Remove

the

screw

2.

Remove

the

solder

from

the

wires.

Removal

of

mechanism

Ass’y

1.

Remove

the

counter

belt.

2.

Remove

the

four

screws

Removal

of

phono

board

1.

Remove

the

two

screws

a3)

‘

2.

Remove

the

connector

wires

from

the

amplifier

board.

Removal

of

LED

board

1.

Remove

two

screws

a4

:

Removal

of

counter

1.

Pull

in

the

direction

of

the

arrow.

PC-70

L/LB/LD/LS

loner

AmpiSP

lager

Amptsk

ie

=

VS

(11)

0PsP30062%2

Ay

Fig.

13

Aa

oy

(1g)

S8SF3008

x2

SDST3006Z

x

2

13}

42)

SBSF30122Z

x4

oS

Fig.

14

(No.

1543)

9

PC-70

L/LB/LD/LS

Removal

of

chassis

base

1.

Remove

the

two

screws

(15)

:

Removal

of

SEA

board

1.

Remove

the

two

screws

and

(1

2.

Remove

the

connector

from

CN104

of

the

amplifier

board.

Mechanism

Parts

1.

Flywheel

and

belt

1)

Remove

two

screws

(B)

fastening

the

F.R.

bracket,

and

remove

the

main

belt.

2)

Pull

out

the

flywheel

with

the

reel

drive

belt.

2.

Reel

assembly

unit

Remove

4

screws

(A)

fastening

the

reel

ass’y

unit.

3.

Motor

1)

Remove

two

screws

fastening

the

motor

from

the

F.R.

bracket.

2)

Pull

out

the

motor

pulley

from

the

motor

shaft.

4.

Reel

feather

Pull

out

the

reel

feather

from

the

shaft.

10

(No.

1543)

4.

(15)

SBSF

30122

«2

Fig.

15

17)

sBsF

30122

46:

LPsP

30087

PC-70

L/LB/LD/LS

5.

Rec/PB

head

and

Erase

head

1)

Remove

two

screws

©

fastening

the

button

frame

ass’y.

2)

Remove

two

screws

(0)

fastening

the

head

ass’y

with

the

head

block.

Reel

feather

Fig.

18

Operating

principle

of

Mechanical-logic

Auto-reverse

Mechanism

is

the

same

as

those

of

the

service

manual

for

KD-V33

A/B/C/E/E(D)/J/U

(No.

4222B).

Please

refer

to

the

service

manual

of

KD-V33

A/B/C/E/E(D)/J/U

(No.

4222B).

How

to

Engage

Dial

Cord

1.

Turn

the

dial

drum

fully

clockwise

(to

the

highest

frequency).

2.

Use

Kevlar

cord

(695

mm

long

and

0.4

mm

in

diameter).

3.

Install

the

string

in

the

sequence

of

the

numbers.

Bonding

Pointer

Wind

on

the

tuning

shaft

two

turns.

Turn

the

dial

dram

fully

clock

wise

Fig.

19

(No.

1543)

11

PC-70

L/LB/LD/LS

Main

Adjustments

[1]

1.

Electrical

adjustment

1)

Electronic

voltmeter

2)

Audio

frequency

oscillator

(range:

50—

20

kHz

and

output

OdB

with

im-

pedance

600

Q)

3)

Attenuator

4)

Standard

tapes

for

REC/PB

Maxell

UD

—

TDK

SA

—

Chrome

tape

(TS-6)

JVC

ME

—

Metal

tape

(TS-7)

5)

Reference

tapes

for

playback

(JVC

Test

Tape)

VTT702

(for

head

azimuth

adj.)

Normal

tape

(TS-5)

\

or

equivalent

VTT712

(for

motor

speed,

wow

flutter

adj.)

(H]

1.

Adjustment

Mechanical

Adjustment

Procedure

of

Cassette

Mechanism

Equipment

and

Measuring

Instruments

used

for

Adjustment

VTT664

(for

reference

level

1

kHz)

VTT739

(for

playback

frequency

response)

VTT6447

(for

music

scanning)

VTT6448

(for

music

scanning)

6)

Resistors

600

©

(for

attenuator

matching)

2.

Mechanical

adjustment

1)

Torque

testing

cassette

gauge.

3.

Tuner

section

adjustment

SSG

(standard

signal

generator).

Sweep

signal

generator.

(Adjust

the

mechanism

or

confirm

that

it

is

in

normal

operating

condition

prior

to

the

adjustment

of

the

electrical

circuit.)

Item

Adjustment

Adjusting

|

Standard

Remarks

point

value

Adjusting

Connect

a

speed

meter

(an

electronic

|

Semi-fixed

|3000

Hz

If

the

speed

meter

functions

as

a

motor

speed

counter)

to

the

Speaker

out

terminals.

|

resistor

in

wow

and

flutter

meter,

also,

connect

Play

back

the

VTT712

test

tape.

the

DC

{the

deck

to

the

INPUT

terminals

of

Adjust

the

semi-fixed

resistor

in

the the

meter.

motor

until

the

reading

of

the

speed

meter

is

3000

Hz.

Checking

wow

|

Connect

a

wow

and

flutter

meter

to

0.08%

If

the

reading

becomes

moving

value

and

flutter

Seaker

out

terminals.

(WRMS)

even

if

conforming

to

the

standard,

a

Play

back

the

VTT712

test

tape.

0.18%

reclaim

may

be

raised.

Repairs

are

Check

to

see

if

the

reading

of

the

(DIN

necessary.

meter

is

within

0.08%

(WRMS).

45500)

Checking

play-

|

Employ

a

torque

testing

cassette

tape

40—70

If

the

standard

torque

is

not

obtained,

back

torque

CTG-N

for

the

checking,

or

remove

gr-cm

replace

the

take-up

disc

assembly.

the

cassette

cover

and

use

a

torque

gauge.

Checking

fast

|

Measure

the

torque

in

the

fast

forward

More

than

If

the

standard

torque

is

not

obtain-

forward

torque

|

mode

in

the

same

manner

as

in

the

80

gr-cm___|ed,

perform

the

following.

above.

1.

Clean

the

capstan

belt,

the

idler

circumference,

the

motor

pulley,

the

take-up

reel

disc

circumfer-

ence,

the

flywheel

circumference,

etc.

2.

Replace

the

belt

and

idler.

Checking

Measure

the

torque

in

the

rewind

More

than

|If

the

standard

torque

is

not

obtain-

rewind

torque

mode

in

the

same

manner

as

in

the

80

gr-cm__|ed,

clean

the

capstan

belt,

idler,

above.

motor

pulley,

flywheel

circumfer-

ence,

rewinding

idler

circumference,

left

reel

disc

circumference,

etc.

Adjusting

1)

Use

TMT702

or

equivalent

and

set

|

Head

Maximum

|

record/

the

output

to

maximum.

mount

playback

head

2)

Adjust(A)or(B)to

obtain

the

max-

|

azimuth

position

imum

value

in

both

forward

and

|

screws

@

®

reverse

modes.

Confirm

the

adjust-

|

and

Ahestad

ment

by

recording

and

reproducing

Forwano/

“|

reverse

a

14

kHz

signal

and

checking

the

Forward

Reverse

normal

level.

12

(No.

1543)

PC-70

L/LB/LD/LS

{IIl]

Cassette

Amplifier

Adjustment

Parts

Side

VR201

Rec/P.B.

Response

Adj

101

FS

Pattern

8

S

P.B,Output

Level

Adj.

L101

R151

R251

Bias

Frequency

Adj.

Fig.

20

Cassette

recorder

section

,

Tape

to

Fr

:

-

Item

bé-used

Adjustment

and

check

Adjustment

point

Tt

red

Playback

output

VTT664

Play

the

VTT644

and,

when

the

L

and

R

level

difference

is

|

R151

or

R251

level

(1

kHz)

more

than

2

dB,

perform

this

adjustment.

For

the

channel

with

lower

level,

shortcircuit

the

slit

pattern

with

R151

or

R251.

Playback

frequency

|

VTT739

When

playing

VTT739

and

assuming

1

kHz

level

at

O

dBs,

response

125

Hz

shall

be

+1

dB

+3

dB,

and

8

kHz

shall

be

+1

dB

+3

dB.

Bias

frequency

Connect

a

frequency

counter

to

TP101

(on

the

H

side

of

|

L101

adjustment

R101)

and

adjust

L101

to

obtain

68

kHz.

Recording

and

Apply

signals

—

20

dB

under

the

reference

input,

and

record

|

VR101

and

playback

frequency

and

reproduce

1

kHz,

100

Hz

and

8

kHz.

Then

adjust

VR101

|

VR201

response

and

VR201

so

that

100

Hzis

OdB

+3

dB,

and

8

kHzis

+1

dB

+3

dB.

In

this

adjustment,

the

L

and

R

difference

when

recording/

playing

1

kHz

signal

shall

be

within

3

dB.

Recording

and

Record

and

reproduce

1

kHz

reference

level

signal

and

|

playback

distortion

measure

the

distortion.

The

values

shall

be

within

3%.

|

(No.

1543)

13

PC-70

L/LB/LD/LS

[IV]

Tuner

Alignment

POWER

SOURCE

OF

THE

RECEIVER

BASIC

CONDITIONS

DC

12V

AC240/220/110

V,

50/60

Hz:

LOAD

RESISTANCE

OF

THE

RECEIVER

50

mW

(0.4

V)/3.2

0

MODULATION

OF

SSG

400

Hz.

30%

Item

1.

AM

IF

ALIGNMENT

1

Conditions

of

the

receiver.

)

Power

source:

(2)

Function

switch

position:

(3)

Band

select

switch:

(4)

Volume

control:

(5)

SEA

control:

(6)

Variable

capacitor:

1-2

Connection

of

Sweeper

and

the

receiver

(1)

Tuner

input:

(2)

Tuner

output:

1-3

Aligning

position:

1-4

Alignment

(Waveform):

2.

FM

IF

ALIGNMENT

2-1

Conditions

of

the

receiver

(1)

Power

source:

(2)

Function

switch

position:

(3)

Band

select

switch:

(4)

Volume

control:

(5)

SEA

control:

(6)

Variable

capacitor:

2-2

Connection

of

Sweeper

and

the

receiver

(1)

Tuner

input:

(2)

Tuner

output:

NOTE

Description

DC

7.7

V

{only

Tuner

P.C.

Board)

(When

the

power

is

supplied

directly

to

the

tuner

in

the

receiver,

the

voltage

should

be

adjusted

to

the

proper

level

which

shail

be

required

by

the

tuner.)

RADIO

MW

Minimum

gain

position

Center

position

Near

the

minimum

capacity

position

where

no

signal

come

in.

Positive

side

to

TP4

Positive

side

to

TP2

j

Negative

side

to

TP3

T3,

T4

Adjust

AM

I.F.T.

(above

mentioned

aligning

position)

so

that

maximum

and

symmetrical

wave

form

can

be

obtained.

In

this

case,

the

wavehead

should

be

appeared

at

the

center

marker

(450

kHz)

on

the

scope

of

Sweeper.

Same

as

mentioned

in

item

1-1

RADIO

FM

Minimum

gain

position

Center

position

Near

the

minimum

capacity

position

where

no

signal

come

in.

Positive

side

to

TP1

(C5

or

R5)

Positive

side

to

TP2

Negative

side

to

TP3

a)

Attach

a

capacitor

(30

pF)

and

resistor

(30

kQ)

in

series

to

the

positive

side

cable

which

shall

be

led

from

Sweeper

input.

b)

Attach

a

capacitor

(30

pF)

and

a

resistor

(100

kQ)

in

series

to

the

positive

side

cable

which

shall

be

led

from

Sweeper

output.

2-3

Aligning

position:

2-4

Alignment

(Waveform):

b)

Discriminate

Waveform:

a)

IF

Waveform:

T1

b)

Discriminate

Waveform:

T2

(’S’’

curve

waveform)

Adjust

the

discriminate

coil

(T2)

so

that

‘’S’’

curve

waveform

may

be

changed

to

IF

waveform

as

shown

in

following

figure.

After

above,

adjust

T1

so

that

max.

sensitivity

and

sym-

metrical

IF

waveform

can

be

obtained

on

the

scope

of

Sweeper.

Adjust

the

discriminate

T2

again

so

that

above

symmetrical

IF

waveform

may

be

changed

to

balanced

‘‘S’’

curve

waveform.

|

14

(No.

1543)

PC-70

L/LB/LD/LS

Item

Description

3.

AM

RF

ALIGNMENT

3-1

Conditions

of

the

receiver.

(1)

Power

source:

Same

as

mentioned

in

item

1-1.

(2)

Function

switch

position:

RADIO

(3)

Volume

control:

50

mW

(4)

SEA

control:

Center

position

(5)

Variable

capacitor:

Refer

the

following

list

shown

in

item

3-4.

3-2

Conditions

of

SSG.

(1)

Modulation:

Refer

the

basic

condition

(2)

Frequency:

Refer

the

following

list

shown

in

item

3-4.

(3)

Output

level

of

the

attenuator

in

SSG:

Approx.

50

mW

3-3

Power

output

measuring

position:

Speaker

terminals

3-4

Alignment:

PC-70

VV

meter

32a

|

£5

ak

7

ETD

VQPO0003-471

7

=

it

Band

Select

{Sort

of

Antenna

to

be

+

:

a

Aligning

Switch

Position

attached

to

SSG

Frequency

of

SSG

Variable

Capacitor

Position

145

kHz

Max.

capacity

L6

2

360

kHz

Min.

capacity

TC-6

3

LW

Loop

Antenna

Adjust

the

above

aligning

position

(L6

&

TC-6)

repeatedly

so

that

the

tuner

can

be

received

above

frequency

range

(band

width).

<a

160

kHz

to

be

received

160

kHz

L2

5

350

kHz

to

be

received

350

kHz

TC-2

6

Adjust

the

above

aligning

position

(L2

&

TC-2)

repeatedly

so

that

the

tuner

can

be

obtained

the

best

sensitivity.

7

520

kHz

Max.

capacity

L7

|

8

|

1,650

kHz

Min.

capacity

TC-7

9

MW

Loop

Antenna

Adjust

the

above

aligning

position

(L7

&

TC-7)

repeatedly

so

that

the

tuner

can

be

received

above

frequency

range

(band

width).

ara

|

10

620

kHz

to

be

received

620

kHz

L3

11

1,400

kHz

to

be

received

1,400

kHz

TC-3

12

Adjust

the

above

aligning

position

(L3

&

TC-3)

repeatedly

so

that

the

tuner

can

be

obtained

the

best

sensitivity.

13

5.8

MHz

Max.

capacit

L8

tes

pacity

14

18.6

MHz

|

Min.

capacity

TC-8

15

sw

Dummy

Adjust

the

above

aligning

position

(L8

&

TC-8)

repeatedly

so

that

Antenna

the

tuner

can

be

received

above

frequency

range

(band

width).

16

Note

6

MHz

to

be

received

6

MHz

L4

si

17

Positive

side

to

TP5

18.0

MHz

to

be

received

18.0

MHz

TC-4

Negative

side

to

Adjust

the

above

aligning

position

(L4

&

TC-4)

repeatedly

so

that

TP8

i

the

tuner

can

be

obtained

the

best

sensitivity.

18

4

——________i__

(No.

1543)

15

PC-70

L/LB/LD/LS

Item

Description

4.

FM

RF

ALIGNMENT

4-1

Conditions

of

the

receiver.

(1)

Power

source:

(2)

Function

switch

position:

(3)

Band

select

switch:

(4)

Volume

control:

(5)

SEA

control:

(6)

Variable

capacitor:

4-2

Condition

of

FM

SSG.

(1)

Modulation:

(2)

Frequency:

(3)

Output

level

of

the

attenuator

in

FM

SSG:

4-3

Alignment:

Same

as

mentioned

in

item

1-1.

RADIO

FM

50

mW

Center

position

Refer

the

following

list

shown

in

item

4-3.

Refer

the

basic

condition

Refer

the

following

list

shown

in

item

4-3.

The

level

shall

be

decided

by

the

load

resistance

of

the

receiver

mentioned

in

the

basic

conditions.

Dummy

eM

Antenna

LEE

Positive

side

to

TP5

Negative

side

to

TP8

FM

MPX

Alignment

A.

19

kHz

Alignment

(Regular

Method)

1.

Connect

a

frequency

counter

to

the

test

point

TP7

(earth

=

TP3).

2.

Supply

the

monaural

signal

(98

MHz,

60

dB)

across

the

antenna

terminal.

3.

Adjust

the variable

resistor

VR1

so

that

the

frequen-

cy

becomes

19

kHz

+

100

Hz.

Parts

Arrangement

for

Alignment

(MW

ANT)

i

(LW

ANT)

apie

aesee

DTA

Band

Select

|

Sort

of

Antenna

to

be

F

‘

ah

Aligning

Switch

Position

attached

to

SSG

Frequency

of

FM

SSG

|

verai

Capacitor

Position

87.5

MHz

|

Max.

capacity

|

L5

109.0

MHz

Min.

capacity

[|

Tes

Ajust

the

above

aligning

position

(L5

&

TC-5)

repeatedly

so

that

the

tuner

can

be

received

above

frequency

range

(band

width).

90

MHz

to

be

received

90

MHz

106

MHz

to

be

received

106

MHz

Adjust

the

above

aligning

position

(L1

&

TC-1)

repeatedly

so

that

the

tuner

can

be

obtained

the

best

sensitivity.

B.

19

kHz

Alignment

(Simplified

Method)

1.

Tune

to

an

FM

stereo

broadcast.

2.

Set

the

variable

resistor

VR1

to

the

minimum

position

of

the

range

in

where

the

Lch

and

Rch

selecting.

Note:

Attach

a

resistor

(100

kQ)

to

the

positive

side

cable

shall

be

led

from

counter

input.

Dummy

Antenna

16

(No.

1543)

=.

FP

=5

|

ts

Le

TC3

“Ee

ss{

{se}

}s3[|s2

|"

g

2

Be

Se

tw}

[mw

{sw]

[FM

Wy

ul

a

I

L2L3_

(FM

ANT)

(FM

IF

MONO

Le

cs

(LW

OSC)

Sw

14.

@D

@

[O]

(

[Q]

eswantr

Pr

16

@)

@rc7

fant

2]

TP-8

TC1(FM

ANT)

RS

R,+R,=802

"A"

=

TP-5

P-4

{

1

(swosc)

C5

Hgts

C=10

pF

E

—

TP-8

(AMIF)S

16

[Q]us

C8

(FM

OSC)

=

p

(osc)

7

(Sw

OSC)

it

TI

R,

:

Output

impedance

of

S.S.G.

(MW

OSC)

(FM

OSC)

(FM

IF)

19kH

=

VRI

‘

ie

“ey

(19

kHz)

Fig.

22

R33

(AM

1F)

(FM

DISC)

(FM/AM

IF)

Fig.

21

|

PC-70

L/LB/LD/LS

Wiring

Connections

1

2

3

4

5 6

Telescopic

Antenna

A

Ferrite

Core

Antenna

Solenoid

Os

|)////)///;

a

B

Direction

SW

C

Head

Mount

Ass’y

D

|

gree

oe.

7

®

Q-

i

ae

2

Color

code

are

shown

below

Orange

(No.

1543)

17

Block

Diagram

Tuner

Section

|

PC-70

L/LB/LD/LS

P.B.

System:

M.S.

1C351

LA2000L

1)

Telescope

Antenna

Pre

Amp

S.E.A.

Circuit

1¢101

1C

301

M5218L

ee

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(No.

1543)

18

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53,

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VIEW

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line

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the

signal

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line

shows

the

signal

at

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—+—

+Bcircuit

Fig.

28

10

JVC PC-70L User manual

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