Dual 1216 Manuel utilisateur

Table des matières

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Dual

Edition

January

1972

Technical

data

Power

supply

Power

supply

voltage

Drive

Power

consumption

Current

drain

Turntable

platter

Turntable

speeds

Pitch

control

variation

Dual

1216

Service

Manual

alternating,

50

or

60

cycle

changeable

by

changing

motor

pulley

110/117

and

220/240

V,

switchable

4

-pole

asynchronous

pole

motor

with

radialelastic

suspension

5

10

watts

64

ma

approx.

at

220V,

50

cycle

115

ma

approx.

at

117

V,

60

cycle

weighing

3.2

lbs.

or

4

lbs.,

dia

10

5/8

inch.

33

1/3,45

and

78

r.p.m.

adjustment

range

of

approx.

1

semitone

(6

%)

at

all

three

turntable

speeds

Speed

accuracy

deviation

<

0.12%

with

platter

4

lbs.

to

DIN

45

500

<

0.15%

with

platter

3.2

lbs.

Rumble

35

dB

below

signal

level

in

accordance

to

DIN

45

500

Weighted

rumble

55

dB

below

signal

levet

in

accordance

to

DIN

45

500

Tonearm

torsionally

rigid,

aluminium

tubular

tonearm

with

vertical

needle

bearings,

horizontal

2-layer

precision

ball

bearings

in

hardened

and

polished

races.

Maximum

tracking

error

0.18

0

/cm

Tonearm

bearing

frictions

(referred

to

stylus

tip)

vertical:

less

than

0.01

gram

horizontal:

less

than

0.04

gram

Cartridge

holder

removable,

suitable

for,acceptance

of

cartridges

having

1/2"

mounting

and

possessing

a

weight

of

1

- 8

grams.

Weight

aprox.

10.6

lbs.

with

platter

4

lbs.

aprox.

9.7

lbs.

with

platter

3.2

lbs.

Dimensions

and

mounting

cutouts

see

instal

lation

instructions

Dual

Gebrüder

Steidinger

•

7742

St.GeorgeniSchwarzwald

Download from www.dual.de

Not for commerical use

Fig.

1

Tonearm

hookup

schematic

right

channel

left

channel

,

channel

1

channel

2

1 1

r-

._

i

r

__

c

.

white

>

--.1

---21

L----1

F

---f.''l

..

.-r---.

I

1

----1 >.

1

red

L

----

1---<

-

I

r

>

'-----1

. .

L

----J.

I I

,J----I

L J L

-J

i%

I

I

-I

1

„

1

1

1--

______

__

--f

: 1

:'

'---

Tonearm

audio

lead

I

I

I

1

c

-----

rti

(1

1

a)

with

miniature

5-pin

plug

tonearm

junction

board

with

muting

switch

\

1

n

.L:

171

2

channel

1

red

lead

contact

plate

at

plug-in

head

plug-in

head

with

cartridge

green

mu-metal

housing

of

cartridge

phonograph

record

inner

side

of

groove

left

channel

7- •

channel

1

red

Q

2

tonearm

circuit

1

r

r

-

r

-1

channel

2

white

1

channel

2

white

lead

b)

with

phono

plug

red

yellow

c)

with

banana

plugs

channel

1

=

red

channel

2

=

yellow

common

=

black

ground

=

green

plug-in

head

spring

contacts

between

plug-in

cartridge

head

and

tonearm

white

blue

outer

side

of

groove

1

right

channel

2

Co

ntents

"bre

Technical

data

Tonearm

hookup

schematic

Motor

and

drive

Pitch

Control

Page

1

2

4

5

Turntable

does

not

run

when

unit

is

plugged

in

and

"starr

switch

operated

5

Turntable

does

not

come

up

to

speed

5

Rumble

in

reproduction

5

Correct

nominal

speed

obtained

only

at

extreme

settings

of

pitch

control

5

Tonearm

head

is

not

parallel

to

turntable

platter

5

Tonearm

and

tonearm

bearing

6

Antiskating

adjustment

7

Stylus

skips

7

Tonearm

sets

down

beside

tonearm

rest

7

Horizontal

pivot

friction

too

high

7

Tonearm

movements

8

Tonearm

lift

(Cue

control)

8

Tonearm

misses

edge

of

record

9

Tonearm

strikes

record

during

change

cycle

9

Tonearm

does

not

move

onto

record

when

drop

cycle

is

started

9

Tonearm

lowers

too

quick

ly

when

drop

cycle

is

started

9

Tonearm

returns

to

rest

immediately

after

being

placed

on

record

manually

9

Start

cycle

9

Manual

start

10

Stop

switching

10

Muting

switch

11

Record

drop

11

Shut-off

and

change

cycle

11

Shut-off

mechanism

12

Turntable

stops

after

automatic

setdown

of

the

tonearm

12

Last

record

keeps

repeating

12

Record

does

not

drop

when

unit

is

switched

to

"Start"

13

Record

drops

when

unit

is

switched

to

"stop"

13

Records

do

not

drop

13

Switch

latches

into

"stop"

position

when

tonearm

is

at

rest

14

Tonearm

moves

with

stylus

force

and

anti-skating

force

at

zero:

a)

outward,

b)

inward

14

During

change,

stop

and

start

operations,

noises

from

the

mechanism

can

be

heard

in

system

speaker

14

No

sound

14

Motor

will

not

shut

off

when

tonearm

is

on

arm

rest

14

Acoustic

feedback

14

Replacement

parts

and

exploded

view

15

-

20

Lubrication

21

Fig.

2

Motor

suspension

and

turntable

drive

102

9

8

113

110

114

105

130

143

108 168

120

Motor

and

drive

The

turntable

platter

and

change

mechanism

are

driven

by

a

vi-

bration-free

four-pole

motor

(168)

with

an

extremely

low

stray

magnetic

field.

Motor

speed

is

constant

for

line-voltage

variations

of

±

10%.

lt

is

dependent

on

(and

proportional

to)

line

frequency.

Two

interchan-

geable

motor

pulleys

(120)

are

available

for

adapting

the

changer

to

50

or

60

Hz

Operation:

Motor

pulley

for

50

Hz

Operation:

Part

no.

220

970

Motor

pulley

for

60

Hz

Operation:

part

no.

220

971

The

motor

pulley

is

secured

to

the

motor

shaft

by

a

setscrew.

When

a

pulley

is

replaced

or

exchanged,

it

must

be

set

at

the

co-

rect

height

(see

Fig.

5).

Fig.

3

Motor

field

connections

(lass

voltage

selector)

104

The

turntable

platter

is

driven

by

the

idler

wheel

(108)

which

is

automatically

disengaged

from

the

motor

pul

ley

when

the

unit

is

shut

off,

in

order

to

protect

its

driving

surface.

Turntable

speeds

of

33

1/3,45

and

78

rpm

are

selected

by

raising

or

lowering

the

idler

wheel

(108)

to

the

appropriate

step

on

the

motor

pulley.

When

the

selector

lever

(8)

is

moved,

the

selector

segment

(112)

rotates.

This

causes

the

lever

(105)

fitted

in

the

slot

of

the

selec-

tor

segment

to

move

in

a

vertical

direction.

\

rhe

idler

wheel

(108)

mounted

on

the

swinging

arm

(130)

is

lifted

off

the

motor

pulley

and

set

down

again

on

the

motor

pulley

step

for

the

adjacent

speed.

Fig.

4

Motor

field

connections

(with

voltage

selector)

1

2

0

—

220/240V

I

—J

4

Pitch

Control

For

turntable

speeds

33

1/3,45

and

78

rpm,

the

unit

incorporates

a

voltage-indenpendent

pitch

control,

wh

ich

permits

a

turntable

speed

variation

of

up

to

6%

(approximately

one

sem

itone).

When

the

pitch

control

knob

(9)

is

turned,

the

switch

segment

(112)

and

the

switch

lever

(105)

attached

to

it

are

moved

up

or

down.

This

vertical

displacement

changes

the

position

of

the

idler

wheel

on

whatever

step

of

the

motor

pulley

it

has

been

placed

on

(by

the

speed

selector),

and,

due

to

the

tapered

shape

of

the

pul-

ley,

effects

approximately

±

3

%

variation

in

speed.

Symptom

Causa

Fig.

5

Motor

pulley

Position

Remedy

Turntable

does

not

run

when

unit

is

plugged

in

and

start

switch

operated

Turntable

does

not

come

up

to

speed

Rumble

in

reproduction

Correct

nominal

speed

obtained

only

at

extreme

settings

of

pitch

control

Symptom

Tonearm

head

is

not

parallel

to

turn-

table

platter

Cause

Orientation

of

tonearm

head

on

tonearm

tube

has

altered

because

of

jolting

in

transport

(shipping)

•

a)

Current

path

to

motor

interrupted

b)

Idler

wheel

(108)

not

in

contact

with

platter

c)

Motor

pulley

loose

a)

Motor

pulley

is

not

correct

for

local

line

frequency

b)

Slippage

between

idler

wheel

(108)

and

motor

pulley

(120)

or

platter

c)

Excessive

friction

in

motor,

drive

wheel

or

platter

bearings

Worn

idler

wheel

Idler

wheel

does

not

contact

motor

pulley

correctly

Remedy

Remove

turntable

platter

with

the

help

of

a

screwdriver

inserted

through

the

hole

in

the

chassis

placed

there

for

the

purpose.

Loosen

screw

on

tonearm

head.

After

cor-

recting

the

tonearm

head,

tighten

screw.

(Fig.

6)

•

a)

Check

connection

at

switch

plate

and

voltage

selector

b)

Check

switch

lever

assembly

(105)

c)

Tighten

motor

pulley

a)

Change

motor

pulley

b)

Clean

friction

surfaces

of

idler

wheel,

motor

pulley

and

turntable

platter.

If

necessary,

replace

drive

wheel.

Once

the

drive

surface

of

the

platter

has

been

cleaned,

do

not

touch

it

with

your

fingers

c)

Clean

and

oil

bearings

Replace

idler

wheel

(108)

and

clean

platter

drive

surface

and

motor

pulley

with

greaseless

solvent.

Once

surface

are

cleaned

do

not

touch

them

with

your

fingers

Loosen

setscrew

(122)

and

by

means

of

setscrew

(119)

adjust

the

motor

pulley

on

the

motor

shaft

so

that

when

the

fine

speed

adjustment

knob

is

in

the

center

of

its

range,

the

idler

wheel

is

positioned

in

the

center

of

the

appropriate

motor

pulley

step.

(Fig.

6).

When

adjustment

is

completed,

tighten

setscrew

(122).

Fig.

6

Tonearm

and

tonearm

bearing

The

tonearm

of

the

Dual

1216

is

counterbalanced

and

pivots

vertically

and

horizontal

ly

on

precision

ball

bearings.

This

ap-

roach

gives

highly

favorable

tracking

characteristics.

The

tone

-

arm

head

is

removable.

To

aid

in

replacing

or

adjusting

the

tonearm

head,

a

hole

is

provided

in

the

turntable

base

to

faci-

litate

mounting

the

tonearm

head

without

first

removing

the

tonearm.

Before

setting

the

correct

stylus

force

for

the

car-

tridge

that

has

been

installed,

the

tonearm

should

be

balan-

ced

with

the

stylus-force

setting

at

zero.

Fig.

7

Tonearm

bearing

assembly

39

28

27

30

31

48

104

170

245

246

49

Fig.

8

Tonearm

bearing

assembly

(under

view)

45

39

37

43

237

232

246

249

192

233

204

250

231

40

45

43

46

47

lt

is

recommended

that

the

balancing

should

be

done

right

next

to

the

tonearm

rest.

The

counterweight

is

so

designed

that

is

can

balance

cartridges

with

weights

from

1

to

8

grams.

For

shock

absorption

.

(the

absorption

of

short,

rapid

jolts)

the

counter-

weight

is

elastically

mounted

on

the

tonearm

and

bracked

to

prevent

unintendet

rotation.

The

tonearm

head

is

designed

to

accept

all

car-

tridges

with

internationally

standard

1/2

inch

mounting

centers

and

with

a

weight

not

exeeding

1-8

grams.

Stylus

force

is

set

ny

turning

a

calibrated

spring

housing

(40),

thus

tensioning

or

slackening

the

spiral

spring

lt

contains.

The

scale

is

calibrated

over

a

range

of

0

to

5.5

grams,

allowing

an

exact

setting

of

stylus

within

that

range

in

0.5

gram

steps.

To

replace

the

tonearm

with

its

bearing

assembly,

the

following

proce-

dure

is

recommended:

1.

Secure

the

unit

in

the

repair

jig,

set

the

stylus

force

to

zero

and

lock

the

tonearm

in

place.

2.

Turn

the

unit

tipside

down

and

unsolder

the

tonearm

leads.

3.

Remove

main

lever

(204)

and

linking

lever

(192).

4.

Connect

the

springs

and

screw

on

the

shield.

5.

Unfasten

the

c-washer

and

remove skating

lever.

6.

After

loosening

the

c-washer

(254)

and

friction

washer

(253)

separate

shutoff

slide

(234)

four

segment

7.

Loosen

cylinder

screw

(245/247)

and

remove

segment.

8.

Hold

the

main

lever

bracket

and

unscrew

the

hex

nut

(

4

a

9.

Pull

out

the

ball

bearing

with

balls

(5

pieces)

10.

Set

the

unit

on

an

upright

position

and

take

out

the

tonearm

together

with

the

main

lever

bracket.

Screw

on

the

hex

nut

until

you

feel

a

swall

resistance.

After

screwing

lt

on

place,

there

must

be

a

noticeable

play.

After

scre-

wing

on

the

cylinder

screw,

test

the

tonearm

by

setting

lt

over

the

tonearm

rest.

The

tonearm

is

correctly

set

when

the

tonearm

can

be

lowered

onto

the

rest

without

binding.

When

reinstalling

the

protective

cover

(237),

be

sure

that

the

segment

(246)

can

move

without

hindrance

though

the

tonearm

leads.

To

remove

the

tonearm

from

its

bearing

frame,

unsolder

the

tonearm

leads,

then

set

the

stylus-force

adjustment

to

zero.

Unscrew

locknut

(28)

with

setscrew

(27)

and

bearing

screw

(45)

(iefthand

thread).

Carefully

lift

the

tonearm

free

from

the

bearing

frame.

6

gen.

Anti-skating

adjustment

The

tendency

of

a

tonearm

with

an

offset

(angled)

head

to

"skate"

inward

across

the

record

is

eliminated

in

the

Dual

1216

by

a

preci-

sion

anti-skating

mechanism.

Skating

force

depends

on

tonearm

geometry,

stylus

force

and

the

tip

radius

of

the

stylus.

The

inward

pull

on

the

tonearm

caused

by

the

skating

effect

gives

rise

not

only

to

an

undesireable

jum-

ping

of

the

tonearm

when

lt

is.set

down

on

the

record,

but

also

to

unequal

forces

on

the

two

opposite

groove

walls,

with

correspon-

ding

III

effects.

This

can

be

corrected

with

proper

anti-skating

adjustment.

By

turning

the

anit-skating

adjustment

knob

(50)

on

the

chassis,

an

asymmetrical

curved

washer

(249)

is

turned.

This

washer

has

two

different

curved

surfaces

corresponding,

respectively

‚to

the

red

and

bleck

scales

on

the

anti-skating

dial.

The

red

scale

is

for

conical

(spherical-tip)

styli;

the

bleck

for

elliptical

(bi

-radial)

sty-

li.

When

the

knob

is

turned,

the

curved

surfaces

push

the

anti-

skating

lever

(231)

away

from

its

rest

position

so

that

is

applies

a

suitable

counterforce

via

a

spring

(233).

Skating

compensation

is

set

at

the

factory

for

conical

styli

with

a

tip

radius

of

0.6

to

0.7

mil

(.0006

-

.0007

inch),

and

for

ellipti-

cal

styli

-

with

measurements

of

0.20

to

0.23

mil

by

0.79

to

0.87

mil.

The

hex

adjusting

nut

is

tightened

and

sealed.

Readjustments

should

be

attempted

only

with

the

help

of

the

Dual

Skate-0-meter

and

test

record

L

096.

This

work

is

best

done

by

an

authorized

Dual

service

agency.

Symptom

Fig.

9

Anti-skating

a)

Anti-skating

in

„0"

b)

Anti-skating

mechanism

in

„1.5"on

the

scale

for

conical

styli.

Tonearrn

on

rest

position

c)

See

„b",

tonearm

onty

over

turntable

Causa

Remecty

Radius

for

saniere

styli

Radius

•

r

elliptical

styli

Anti-skating

1

Skating

force

Anti-skating

mechanism

Stylus

skips

Tonearm

sets

down

beside

tonearm

rest

Horizontal

pivot

friction

too

high

a)

Tonearm

not

balanced

a)

Balance

tonearm

according

to

operating

instructions

b)

Stylus

force

too

low

b)

Set

stylus

force

to

cartridge

manufacturer's

recommen-

ded

value

c)

Stylus

worn

or

chipped

c)

Replace

stylus

d)

Excenssive

friction

in

d)

Check

tonearm

horizontal

pivot.

Should

have

barely

tonearm

bearing

noticeable

play.

Adjust

vertical

bearing

only

with

the

left

bearing

screw

(27)

and

the

horizontal

bearing

with

nut.

Horizontal

bearing

is

correctly

adjusted

when

the

tonearm,

with

anti-skating

0.5

p,swings

freely

from

center

to

rest

e)

Ball

(235)

missing

from

shut-off

e)

Replace

ball

(235)

raul

f)

Anti-skating

wrongly

adjusted

f)

Correct

antiskating

setting

Arm

segment

(246)

incörrectly

ad-

justed

Tonearm

is

set

too

high

on

tone

-

arm

lift.

Main

lever

jams

against

guide

pin

of

lift

screw

assembly

Correct

segment

positioning:

after

loosening

screws

(245/

247)

rotate

segment

(246).

Adjustment

is

correct

when

the

tonearm

descends

to

the

tonearm

rest

without

binding.

Stylus

should

be

no

farther

from

record

surface

than

1/4".

Adjust

by

turning

screw

(211).

Fig.

10

Tonearm

guide

mechanism

171

239

18

204

Tonearm

lift

(Cue

control)

The

tonearm

lift

permits

the

tonearm

to

be

set

down

on

the

record

safely

at

any

desired

point

except

the

shut-off

area

(near

the

record

label).

Pulling

the

tonearm

lift

towards

the

front

turns

the

drive

washer

(207).

This

moves

the

connecting

lever

(192),

main

lever

(204)

and

lift

screw

(229)

to

raise

the

tonearm.

After

the

tonearm

is

moved

(by

hand)

to

the

desired

spot

on

the

record,

the

tonearm

lift

handle

is

lightly

tapped

towards

the

rear

Fig.

11

Tonearm

lift

(tonearm

raised)

244

185

Tonearm

movements

A

guide

groove

located

on

the

underside

of

the

main

cam

(197)

controls

the

automatic

lift

and

set-down

of

183

the

tonearm

as

the

cam

rotates

trought

360

0

.

Tonearm

lift

and

lowering

are

controlled

by

the

main

lever

(204)

and

the

lift

screw

(229).

Horizontal

movements

are

con-

trolled

by

the

main

lever

(204)

and

the

segment

(246).

Setting

the

changer

for

playback

of

7",

10"

or

12"

discs

is

done

with

the

indexing

lever

(33).

Setdown

points

are

determined

by

the

eccentric

portion

of

the

arm

position-

ing

slide

(243)

and

the

indexing

lever

(242).

192

Horizontal

movement

of

the

tonearm

is

limited

by

the

arm

segment

striking

the

arm

positioning

slide

(243).

During

the

change

cycle,

the

main

lever

(204)

raises

the

234

arm

positioning

slide,

bringing

lt

within

reach

of

the

spring

stud.

On

completion

of

the

change

cycle

(set-

down

of

the

tonearm

on

the

record),

the

arm

position-

ing

slide

(243)

is

again

released

and

returns

to

its

nor-

mal

position.

lt

thus

moves

out

of

reach

of

the

spring

stud,

permitting

the

tonearm

to

move

horizontally

without

hindrance,

while

playing

the

record.

243

181

143

215

197

to

release

the

mechanism.

The

connecting

lever

(192)

and

the

leaf

spring

(186)

of

the

main

lever

are

freed,

allowing

the

tonearm

to

fall.

The

rate

of

fall

is

controlled

by

silicone

grease

on

the

drive

washer

(207).

The

height

of

the

stylus

above

the

record

can

be

varied

from

zero

to

about

1/4"

by

adjusting

setscrew

(211).

Turning

lt

to

the

right

increases

the

height,

turning

lt

to

the

left

decreases

the

height.

35

210

208

192

215

211

246

219

229

204

8

Symptom

Cause

Remedy

4rEI

Tonearm

misses

edge

of

record

a)

Set

-down

incorrectly

adjusted

b)

Record

not

standard

size

c)

Friction

surfaces

of

tonearm

clutch

dirty

Tonearm

strikes

record

during

Tonearm

height

incorrectly

set

change

cycle

Tonearm

does

not

move

onto

re-

cord

when

drop

cycle

is

started

Tonearm lowers

too

quickly

when

drop

cycle

is

started

Damping

too

great,

drive

washer

dirty

Too

I

ittle

damping

Tonearm

returns

to

rest

immediately

Shut-off

mechanism

has

shifted

after

being

placed

on

record

manually

out

of

position

during

shipping

Start

cycle

Moving

the

start

switch

(32)

moves

the

switch

lever

(181)

towards

the

main

cam

(197),

initiating

the

follo-

wing

sequence.

a)

The

set

screw

of

the

switch

lever

assembly

(181)

turns

the

switch

arm

(143)mounted

on

the

grooved

shaft

(185).

Via

a

tension

spring,

this

actuates

the

rocker

assembly

(105)

and

engages

the

idler

(108)

between

the

platter

(7)

and

the

motor

pulley

(120)

At

the

same

time,

the

power

switch

(141)

is

actu-

ated

by

the

switch

slide

(138)

through

the

switch

arm,

and

the

turntable

begins

to

rotate.

b)

The

switch

lever

(181)

is

brought

within

reach

of

the

cam

follower

lever

(236),

so

that

it

is

pushed

into

the

change

position

after

the

rotation

of

the

main

cam.

a)

Adjust

set-dwon

with

a

12"

record

so

that

stylus

touches

record

aproximately

1/16"

inside

edge

of

record.

Adjust-

ment

will

be

correct

for

other

sizes

b)

Use

standard

records

C)

Clean

clutch

surfaces

Adjust

arm

height

with

screw

(30).

Height

is

correct

when

stylus

tip

is

1/16"

to

1/8"

above

start

switch

(32)

when

arm

is

removed

from

rest

lowered

Loosen

nut

(205)

and

washer

(206)

and

coat

both

sides

evenly

with

silicone

grease.

Reassemble

and

wipe

off

excess

grease

Loosen

nut

(205)

and

washer

1206)

and

drive

washer

(207).

Clean

thoroughly.

Coat

both

sides

evenly

with

silicone

grease,

re-assemble

and

wipe

off

excess

Before

using

changer

after

moving,

run

lt

through

start

cycle

with

tonearm

locked

on

rest

Fig.

12

Start

position

215

197

176

182

192

208

210

244

143

191

185

183

181

147

146

242

Fig.

13

Stop

position

197

215

indlainimebo

:i

e

.

7

,7

1011

e,

,

,pi.s.,

.

.

\

4...--,

•

••:•••‚•

-----

-

-

,

G

.

N.Zie-

,

‚-•••,...

:

•;

N.,......

"

.

..

192

176

182

181

208

Fig.

14

Muting

switch

210

244

Cam

wheel

at

zero:

Contacts

of

muting

switch

opened

Cam

wheel

is

turning:

Contacts

of

muting

switch

closed

Moving

the

operating

switch

also

releases

the

start

lever

(183),

pulling

it

towards

the

main

cam

by

means

of

the

tension

spring

(182).

This

causes

coil

spring

to

bring

the

143

shut-off

lever

(222)

within

range

of

the

main

cam

dog.

Thus

the

shut-off

lever

drives

the

main

cam.

To

prevent

malfunctioning,

the

operating

switch

is

locked

during

the

start

cycle

(that

is,

while

the

main

cam

is

183

turning).

Just

before

the

main

cam

reaches

its

neutral

Position

(at

the

end

of

the

change

cycle),

the

start

lever

is

pushed

clear

of

the

main

cam

by

the

start

pin

of

the

main

cam.

This

restores

the

switch

lever

and

operating

switch

to

their

original

positions.

After

Instal

lation

and

also

after

moving

the

changer,

the

147

unit

should

be

started

with

the

tonearm

locked

on

the

rest.

This

will

automatically

re-adjust

the

shut-off

lever,

which

may

have

shifted

out

of

position.

191

185

146

242

Manual

start

When

the

tonearm

(16)

is

swung

inward

by

hand,

the

pawl

on

the

switch

arm

drops

into

a

support

on

the

base

plate,

holding

the

switch

arm

in

this

position

and

the

idler

wheel

(108)

in

contact

with

the

platter.The

slide

(138)1inked

with

the

switch

arm

actu-

ates

the

power

switch

and

sets

the

turntable

platter

rotating.

On

reaching

the

run-out

groove,

the

tonearm

automatically

re-

turns

to

its

rest

position

and

the

unit

shuts

itself

off.

(See

shut-

off

mechanism,

next

side).

However,

if

the

tonearm

is

lifted

off

the

record

manually

and

returned

to

the

rest,

the

tabs

of

the

arm

segment

(246)

release

the

pawl.

The

torsion

spring

(176)

then

returns

the

switch

arm

to

its

initial

position,

opening

the

power

switch

and

disengaging

the

idler

wheel.

Stop

switching

When

the

operating

lever

is

moved

to

"stop",

the

starting

lever

(183)

is

pushed

forward.

As

a

result

the

shut-off

linkage

comes

into

contact

with

the

main

cam.

The

svvinging

lever

(236)

remains

in

its

stop

position.

10

When

the

tonearm

is

on

its

rest

and

the

operating

lever

is

pushed

to

"stop",

the

operating

lever

must

not

(am.