Panasonic Rs-790s User manual

PRDER

NO.

ARD-711034

MODEL

Hay

i

I

Hue

ool

hn

ut

He

a

mi

wi

SOLID

STATE

4-TRACK

STEREO

TAPE

RECORDER

move.

RS-790S

SPECIFICATIONS

Power

Source:

'

AC:

117

volts

60

cps

Frequency

Response:

_

40~18,000

cps

at

7-1/2

ips

Power

Consumption:

Approx.

50

W

40~10,000

cps

at

3-3/4

ips

Music

Power

Output:

BWx2

_—

on

eres

;

ose

“

Transistor:

288

346

(4)

2B

175A

(4)

oe

a

ae

pe

ee

peat

ee

Output

LINE”

1OKQ

GOdB

(2)

"

ape

P

iu

pu

‘

cr

"

Diode

&

Rectifier:

OA

70

(2)

FR-1M

(1)

25F

(1)

“EXT.

SP”

8Q

(2)

Recording

System:

AC

bias

50

Ke

“HEADPHONE”

8©

(1)

Erasure

System:

AC

erase

Program

Time:

12

hours

for

7”

150%

tape

at

Reel

Size:

7”

max.

;

1-7/8

ips

Track

System:

4

track

stereo

system

Recording

Level

Indicator:

VU

meter

‘ 1

‘nd

.

a”

af

=

2)

Tape

Speed:

3

speeds,

7-1/2,

3-3/4

and

Built-in

Speaker

:

7”

x5”

dynamic

speaker

(

1-7/8

ips

Dimensions:

16-11/16”

(W)

x

17-3/167

(H)

x

9”

(D)

Weight:

Approx.

38-1/4

tb

MATSUSHITA

ELECTRIC

CORP.

OF

AMERICA

Pan-Am

Tiv'g.,

200

Park

Ave.,

New

York,

N.Y.

10017

HAWAII/MATSUSHITA

ELECTRIC

OF

HAWAII

INC.,

205

Kalihi

St.

Honolulu,

Hawaii

96819

CANADA/MATSUSHITA

ELECTRIC

OF

CANADA

LTD.,

1054

Kipling

Ave.

North,

Rexdale,

Ont,

©@OOOGO9OO8

OHO

LOCATION

OF

PARTS

on

@®

®@

©

©®

Fig.

1

Speed

Selector

Switch

Reflector

for

Channe!

2

Speaker

Right

Reel

Tape

Counter

Function

Lever

Stereo/Monaural

Selector

Switch

Stereo

Headphone

Jack

Channel

2

Volume

Control

and

Power

ON/OFF

Switch

Channel

2

Tone

Control

and

Monitor

Switch:

'

VU

Meters

Channel

1

Tone

Control

and

Monitor

Switch

Channel

1

Volume

Control

”

Record

Buttons

ee

®

®28

@

8809

ene

at

Fig.

2

heer

oe

[ett

aie

|

[ss

z

®

QS

—

Pause

Lever

Direction

Push

Buttons

(Forward

and

Reverse)

Left

Reel

Reflector

for

Channel

1

Speaker

Channel

1

Microphone

Jack

Channel

2

Microphone

Jack

Chennel

1

Auxiliary

Jack

Channel

2

Auxiliary

Jack

Channel

1

Line

Output

Jack

Channel

2

Line

Output

Jack

Channel

1

External

Speaker

Jack

Channel

2

External

Speaker

Jack

Speaker

ON/OFF

Switch

Sensing

Pole

for

Automatic

Reverse

Left

Pressure

Roller

Left

Capstan

Record/Playback

Head

for

Reverse

Operation

Erase

Head

for

Reverse

Operation

Tape

Shifter

:

Erase

Head

for

Forward

Operation

Record/Playback

Head

for

Forward

Operation

Right

Capstan

Right

Pressuré

Roller

Automatic

Shut-off

Switch

Sensing

Pole

for

Automatic

Re-reverse

To

nee

SUSE

Ue

ce

BLOCK

DIAGRAM

OF

ELECTRICAL

CIRCUITS

RECORDING

CIRCUIT

“(F)

RECORD

\

~

¥y

aw

EQUALIZATION

|

HEAD

HW:

(RIO

y,

oxo

(113)

ERASE

\~

%

(F)

lhe

AK)

m3

HEAD

%

.

ajo

=

Q

SHS

OSCILLATOR

x

=

fy

x

0)

Xs

~"

1

t

\

XS

(RrO

NM

ee

se

Sian)

eu]

‘gt

EQUALIZATION

v

(t2)

Gri)

—

pe)

m

aD

>

wn

m

ae

RECTIFICATION

(M)

oS

“We

CONSTANT

VOLTAGE

Fig.

3

FORWARD

PLAYBACK

(Fr

HEAD

p

(R)

FORWARD

|

my

REVERSE

i

PLAYBACK

HEAD

PLAYBACK

HEAD

:

tp:

H

|

ik)

}

{

REWIND

PLAYBACK

HEAD

a

Fig.

4

ea

.

HOW

TO

REMOVE

(E)

_

3g

PANEL

foe

(G)

7

;

od

3

;

H

dq

j

'

4

1

(F)

(G)

(C)

|

ran

Fig.

5

;

1.

Remove

the

Head

Cover

(A).

5.

Remove

the

Speed

Selector

Knob

(E).

2.

Remove

the

Volume

Controls

and

Tone

Controls

(B)

6.

Remove

2

Setscrews

(F)

in

the

center.

ke

(4

Controls).

7.

Remove

6

Setscrews

(G)

of

the

Panel,

and

draw

out

3.

Remove

the

Function

Lever

Knob

(C).

the

Panel

Slowly.

4.

Remove

the

Pause

Lever

Knob

(D).

HOW

TO

REMOVE

BODY

CASE

Fig.

6

1.

First

remove

the

Panel.

4.

Remove

the

Body

Case

by

slowly

lifting

it.

2.

Remove

2

Setscrews

(H)

of

the

Mechanism

Chassis.

5.

Lead

Wire

of

the

Speaker

can

be

separated

if

the

3.

Turn

the

set

upside

down,

and

remove

4

Setscrews

Ccnnector

is

removed.

of

Rubber

Feet.

+

i

4

q

5

1

|

«

TAPE

TRANSPORT

OPERATIONS

~

GENERAL

OPERATING

INSTRUCTIONS

RS-790S

is

operated

with

a

3-Position

Lever.

When

this

Lever

is

set

to

PLAY,

the

unit

is

placed

into

the

playback

mode.

and

the

Tape

{Ss

forwarded

to

the

right

or

left

at

a

constant

speed.

When

the

Lever

is

set

to

PLAY

while

pressing

the

Record

Button,

the

unit

is

placed

into

the

recording

mode.

When

the

Lever

is

set

to

FAST

WIND,

the

Tape

is

forwarded

rapidly

to

the

right

or

left.

When

the

Lever

is

set

to

STOP

thereby

releasing

all

the

mechanisms,

the

Tape

stops

running

while

the

Motor keeps

on

rotating.

POWER

SUPPL

The

Channel

2

Volume

Control

Knob

is

used

for

switch-

ing

the

power

source

ON

and

OFF.

When

the

Tape

finishes

during

recording.

playback

or

fast

forwarding.

the

Tension

Arm

switches

off

the

power

source

as

the

Automatic

Shut-Off

Mechanism

functions.

THREADING

OF

TAPE

The

Tape

can

be

threaded

only

when

the

Operating

Lever

is

set

at

STOP.

When

it

is

set

to

other

position

than

STOP,

the

Shut-Off

Arm

rises

out

so

that

the

Tape

cannot

be

threaded.

PLAYBACK

Set

the

Operating

Lever

to

PLAY.

Select

the

direction

of

Tape

by

the

Direction

Buttons.

Tracks

1

and

3

are

played

back

in

the

normal

forward

mode,

while

Tracks

4

and

2

in

the

reversing

mode.

The

Sound

Reflectors

are

opened

so

that

the

best

results

will

be

obtained.

ae

RECORDING

Depress

the

Record

Button

(both

Buttons

in

the

case

of

a

Stereo)

of

the

Channel

of

which

you

desire

to

make

recording.

Set

the

Operating

Lever

to

PLAY.

Select

the

direction

of

Tape

by

the

Direction

Button.

Tracks

1

and

3

can

be

recorded

in

the

normal

forward

mode,

while

Tracks

4

and

2

in

the

reversing

mode.

FAST

FORWARD

When

the

Operating

Lever

is

set

to

FAST

WIND,

the

Tape

is

forwarded

fast

to

the

right

or

left.

Select

the

di-

rection

of

the

Tape

by

the

Direction

Button

before

turn-

ing

the

Operating

Lefer.

When

changing

the

direction

of

-

fast

forwarding,

the

Operating

Lever

should

be

set

to

STOP.

SELECTION

OF

TAPE

SPEED

Tape

speed

can

be

selected

only

while

the

motor

is

rotating

(only

while

the

power

is

supplied).

!f

the

Speed

Selector

Lever

is

moved

with

the

power

source

switched:

~~~"

7

OFF,

the

Belt

may

get

entangled

with

the

Motor

Pulley

when

the

power

source

is

switched

on.

AUTOMATIC

RECIPROCATION

If

you

attach

Sensing

Tape

(Metal

Sensing

Foil)

to

both

ends

of

the

Tape,

continuous

playback

is

available

be-

tween

them

until

the

Tape

stops.

In

the

case

of

re-

cording,

after

a

reciprocal

recording,

the

Tape

does

not

reverse

for

the

2nd

reciprocation,

but

is

taken

up

onto

the

Left

Reel

regardless

of

the

Sensing

Tape.

This

is

in

order

to

prevent

re-recording

on

the.

once

recorded

Tape.

Sent

TREO

TI

A

PLAYBACK

Idler.

Off

Lever

;

|

(Right

Capstan}

Right

Pressure

Roller

oe

re

Se

Brake

Off

Lever

aie

NeoD)

No

:

dM

Main

Cam

Plate

{———5

TY

ee

pa

Left

Pressure

‘Slide

Plate)

//Right

Pressure

Play

Lever

Roller

Lever

;

Roller

Lever

Left

Click

Plate

Right

Click

Plate

Left

Capstan}

|

=

.

i

Pressure

Roller

5

by

Fig.

7

|

‘(See

Figs.

7~9.

The

numerals

in

parentheses

correspond

moves

the

Idler

Operating

Belt

(5),

and

slant

the

Idler

4

to

Ref.

Nos.

inthe

figure.)

Lever

(7),

thereby

pressing

the

Right

Idler

against

the

Bes

;

When

the

Operating

Lever

is

set

to

PLAY,

the

following

Motor

Pulley

and

Right

Reel

Table

Friction

Pulley

(7).

At

~

|

actions

‘occur

simultaneously,

and

the

Tape

is

forward:

the

same

time,

the

motor

pulley

rotation

makes

the

Right

ed

to

the

right

or

left

at

a

constant

speed.

(The

direction

Reel

Table

(8)

turn

to

take

up

the

Tape

through

the

“|

of

the

Tape

is

selected

by

the

Direction

Button.)

Right

Idler

(6).

As

the

Operating

Lever

is

turned,

the

Main

Cam

Plate

The

motor

pulley

rotation

is

transmitted

to

the

Capstan

moves

(1),

and

the

Play

Lever

is

pushed

down

(2).

The

Belt

(4)

and

turn

the

Right

and

Left

Flywheel,

thereby

Play

Lever

Pushes

up

the

Slide

Plate

(3),

and

the

Right

forwarding

Tape

at

a

constant

speed

by

the

Right

and

Left

Paw

Plates

connected

with

it

pushes

the

Right

Left

Capstan

Shafts

(9).

At

this

time

the

R

P.M.

of

the

and

Left

Pressure

Roller

Levers

(4,

6).

The

Pressure

Capstan

Shaft

on

the

tape

takeup

side

is

a

little

more

Roller

Levers

press

the

Pressure

Rollers

to

the

Right

and

than

that

of

the

Capstan

on

the

reverse

side

due

to

Left

Capstan

Shafts,

respectively

(7).

The

pressure

of

reduction

of

the

actual

flywheel

diameter

by

the

belt

the

Pressure

Roller

against

the

Capstan

is

made

by

a

tension,

and

therefore

the

Tape

between

both

Capstans

Spring

(5),

and

is

uniform.

maintains

its

tension.

On

the

other

hand,

the

Brake-Off

Lever

moved

by

the

The

same

applies

to

the

reverse

forward.

The

Plunger

Main

Cam

releases

both

Reel

Table

Brakes

(11),

and

at

performs

selection

of

motor

polarity

and

change

of

the

same

time

moves

the

Idler-Off

Lever.

thereby

making

Heads,

and

the

Tape

is

forwarded

to

the

left

thr

ough

the

Idler

move

freely

(9,10).

During

the

normal

for-

same

actions

as

in

the

normal

forward.

ward,

the

motor

pulley

rotation

(counterclockwise)

(4)

1

i

1

j

i

j

,

1

i

|

{

}

{

|

4

a

t

i

|

i

|

Motor

Pulley

Left

Reel

Table};

Plunger

Lever

‘Left

Capstan

,

ot

(Left

Flywheel}

|

4

ia

“~

(EF

Brake

Arm

Head

Switch

Arm

Capstan

Belt

Idler

Operating

Belt

oe

Right

Idler

Right

Reel

Table

It

5

JN

Right

Capstan

Right

Flywheel

Idler

Lever

RECORDING

When

the

Record

Button

is

depressed,

the

Record/Play-

back

Selector

Switch

on

the

Printed

Base

Plate

is

placed

into

the

recording

mode.

When

the

Operating

Lever

is

turned

to

PLAY,

the

Tape

moves

through

the

same

actions

as

in

playback,

and

carries.on

recording.

AUER!

ASTOR

Se

Te

eee

Oe

OU

he

FAST

FORWARD

|

.

Idler

Lever

Slide

Plate

—

WLLL

LIZZ

|

When

the

Operating

Lever

is

set

to

FAST

WIND,

the

Main

Left

Idler

against

the

Reel

Table

and

Motor

Pulley.

(Since

Cam

Plate

moves

the

Play

Lever

to

bring

down

the

Slide

the

Idler

is

pushed

upward

as

mentioned

above,

it

is

:

Plate.

(See

(1)

and

(2)

of

Fig.

10)

The

Paw

at

the

slide

pressed

against

the

Reel

Table

instead

of

the

Friction

plate

end.

pulls

the

Fast

Forward

Lever,

thereby

pushing

Pulley.)

(See

Fig.

12)

Through

the

Idler,

the

motor

pulley

up

the

Idler

Lever.

(See

Fig.

11)

As

the

motor

rotates,

rotation

makes

either

the

Right

or

Left

Reel

Table

turn

the

Operating

Belt

works

to

press

either

the

Right

or

fast,

thereby

taking

up

the

Tape.

Fig.

12

INSTANT

STOP

(PAUSE

CONTROL)

(See

Fig.

13)

Tape

Shifter

Lever

Fig.

13

L

=

When

the

Pause

Lever

is

depressed

during

playback

or

recording,

the

following

actions

occur

simultaneously

and

the

Tape

stops.

When

the

Pause

Lever

is

turned

down,

the

Inst.

Lever

(3)

moves

the

Right

and

Left

Pressure

Roller

Levers,

thereby

separating

the

Pressure

Roller

from

the

Capstan.

At

the

same

time,

it

turns

down

the

Tape

Shifter

Lever,

thereby

separating

the

Head

Pad

from.

the

‘head,

and

the

Tape

from

the

head

surface.

Also.

the

Inst.

Lever

pulls

the

Brake

Rod,

thereby

putting

on

the

Reel

Table

Brakes.

The

Pause

Lever

is

locked

by

the

Spring.

Either

one

of

the

Pause

Lever

and

Operating

Lever

can

‘be

operated

first.

MECHANICAL

ADJUSTMENTS

PRESSURE

OF

PRESSURE

ROLLER

>

=e

-

Fig.

14

(Pressure

Roller

Lever

Spring

)

Slide

Plate

Assembly

Right

Capstan

(Left

Capstan

j

Left

Pressure

Roller)

(Right

Pressure

Roller

Fig.

15

Specified

Value:

1.4~1.9kg

The

difference

in

pressure

between

the

Right

and

Left

Pressure

Rollers

should

be

less

than

0.25

kg.

Measuring

Method:

.

Use

a

spring

scale

of

2

kg

full

scale.

During

the

playback,

pull

the.

spring

scale

on

the

line

ocamnaacucanseanscunes:

between

the

center

of

the

Capstan

and

that

of

the

Pressure

Roller

in

the

separating

direction,

and

take

the

reading

of

the

spring

scale

when

the

Tape

stops.

(See

Fig.

14)

Adjusting

Method:

eas

Make

the

adjustment

by

use

of

elongation

and

contrac-

tion

of

the

Pressure

Roller

Lever

Spring.

(See

Fig.

15)

Head

Pad

Spring

(Bend

)(

Head

Pad

Spring

(Bend

))

Increase}

Fig.

17

Specified

Value:

(Erase

Head)

mat

’

(Record/Playback

Head)

Measuring

Method:

Measure

the

force

of

separating

the

Pad

from

the

Head

above

the

center

of

the

Pad

Plate

by

use

of

a

tension

5~10g

10~15¢g

gauge.

(See

Fig.

16)

Adjusting

Method:

Make

the

adjustment

by

use

of

bending

of

the

Head

Pad

Spring.

(See

Fig.

17)

TAPE

TAKEUP

TENSION

DURING

PLAYBACK

Right

Reel

Spindle

In

Normal

Forward

Operation

,

Splicing

Tape

|

Fig.

18

Fig.

19

Specified

Value:

23~33¢

Adjusting

Method:

|

—

Measuring

Method:

|...

-

If

the

Friction

Spring

of

the

Reel

Table

is

slided

clockwise

:

4

stages),

the

takeyp

tension

increases.

Make

the

ad-

Make

a

loop

of

7”

Tape

End,

suspend

a

tension

gauge

(

}

r

from

it,

place

the

set

into

the

playback

mode,

and

read

justment

as

to

the

Right

and

Left Reel

Tables,

respec-

the

average

value

during

a

turn

according

as

the

Tape

is

oe

forward

and

reverse

forward

modes).

taken

up.

(See

Fig.

18)

eunncvansenscensvescsaceasnsnousnanaze

paonanausascscensananenenscauazannassaue:

sccemsunsmameemsentenameastestagasnessietetitiestneaeettettate

CT

ATT

TAKEUP

TENSION

DURING

FAST

FORWARD

dl

Adjusting

Method:

.

Make

sure

that

the

Reel

Table

Felt,

Slip

Ring,

etc.

show

no

such

abnormality

as

staining.

There

is

no

special

method

for

this

adjustment.

Specified

Value:

More

than

150g

}

Measuring

Method:

Same

as

that

of

takeup

tension

during

playback,

except-

ing

that

the

set

must

be

placed

in

the

fast

forward

mode.

oxennccoussnccavencsswermaouseraacuses

BACK

TENSION

DURING

PLAYBACK

Specified

Value:

12~25g

fy

Measuring

Method:

Put

the

7”

Tape

on

the

takeup

side,

pull

the

Tape

for

a

turn

in

the

tape

pulling

out

direction,

and

read

the

aver-

age

value.

(See

Fig.

20)

Adjusting

Method:

There

is

no

special

method

for

this

adjustment.

If

the

specified

value

is

not

satisfied,

check

if

there

is

no

stain

or

oil

is

not

out

on

the

Reel

Table

Shaft.

10

|

i

!

'

1

BRAKE

POWER

‘sonuaeasnanennsceuvensqueneettveuseusarasnauaanvowansvuneeesseuassassaveuudescuassaeansassbencovansevastnouscosvacsaruseseeeeseotssecrseusersssevererseces

Brake

Shoe

|

Weak

Power

Direction

Fig.

21

Specified

Value:

(Strong

Power

Direction)

—

ee

200~350g

(Weak

Power

Direction)

40~150

g

The

difference

in

brake

power

be-

tween

the

strong

power

direction

and

weak

power

direction

should

be

more

than

100

g.

(One

side

Strong

Power

Direction,

and

the

other

side

Weak

Power

Direction)

ADJUSTMENT

OF

PAUSE

BRAKE

Tape

Shifter

Lever

(2)

Fig.

23

1.

When

the

Pause

Lever

is

pulled

down

in

the

playback

mod:

The

Pad

Plate

should

move

away

from

the

Head

by

the

time

when

(or

at

the

same

time

that)

both

the

2

Pressure

Rollers

move

away

from

the

Capstan.

If

not,

make

the

adjustment

by

bending

the

(A)

part

of

the

Tape

Shifter

Lever

(1)

by

using

a

screwdriver.

(See

Fig.

23)

Left

Brake

Shoe

awe

Right

Reel

Table

Right

Brake

Shoe

Fig.

22

Measuring

Method;

Suspend

a

tension

gauge

from

the

end

of

the

7”

Reel

Tape

in

the

stop

mode,

pull

it

and

read

the

average

value

for

a

turn

of

the

Reel.

(See

Fig.

21)

Adjusting

Method:

Make

the

adjustment

by

use

of

elongation

and

contrac-

tion

of

the

Right

and

Left

Brake

Springs.

(See

Fig.

22)

Inst

Rod

Adjustment

Plate

Fig.

24

2.

The

Right

and

Left

Brakes

should

be

pressed

against

the

Right

and

Left

Reel

Tables,

respectively,

after

the

Pause

Lever

is

turned

low

and

the

Pressure

Roller

moves

away

from

the

Capstan.

This

timing

can

be

modulated

by

loosening

the

Screw

(B)

shown

in

Fig.

24

and

adjusting

the

Inst.

Rod

Adjusting

Plate.

After

the

adjustment,

the

Screw

(B)

must

be

locked

with

paint.

aocenaasensetnewsreseeocsosevsereanesvenunanseowansersencesatevnessesszessenesne(Gi—"""

HEAD

HEIGHT

2

|

EF)

Head

of

Tape

and

Head

are

as

shown

in

The

relative

positions

eight

can

be

adjusted

by

Screws

Fig.

25.

The

head

h

;

ANGLE

ADJUSTMENT

tO

Sepa

RS-790S

[rrtt"7>

“Vacuum.

Tube’

Playback

Voltmeter

Amplitier

Fig.

26

Testers:

Vacuum

Tube

Voltmeter,

Standard

Tape

for

7

place

the

tape

recorder

into

the

playback

mode.

‘Turn

Ke

(at

7-¥%

ips)

Angle

Adjustment

(or

Tape

on

either

of

the

Angle

Adjustment

Screws

((3)

or

(2)

in

which

recording

is

made

py

a

reliable

tape

re-

Fig.

27)

byal

/4

turn,

and

make

the

adjustment

so

that

corder)

the

reading

on

the

Vacuum

Tube

Voitmeter

connected

Connect

wires

as

shown

in

Fig.

26,

thread

the

Tape

and

to

the

Line

Out

becomes

maximum.

ERASE

HEAD

O@O@

Head

Angle

and

Head

Height

Adjusting

Screws

ed:

that

the

Slit

becomes

The.Angle

should

be

so

adjust

tape

(by

‘observing

with

j

After

adjusting

the

angle

and

h

back

Head,

adjust

the

position

o

perpendicular

to

the

running

ing

to

Fig.

25.

the

eyes).

12

eight

of

the

Record/Play-

f

the

Erase

Head

accord-

BIAS

OSCILLATOR

FREQUENCY

AMPLIFIER

ADJUSTMENTS

fe

Oscilloscope

Fig.

28

Take

the

measurement

in

the

recording

mode.

1.

Connect

the

10Q

Resistor

to

the

Erase

Head

in

series.

2.

Measure

voltage

at

both

ends

of

the

109

Resistor

a

while

comparing

it

with

that

of

the

Standard

Oscillator.

3.

For

comparison,

make

the

Lissajous’

wave

form

in

the

Oscilloscope

Braun

Tube.

4.

When

40~80

mA

current

is

applied

to

the

Erase

Head,

the

Standard

Frequency

shall

be

50

Kc

+

5

Kc

in

the

stereo

recording

mode.

When

CH.

1

is

in

the

recording

mode

and

CH.

2

in

the

playback

mode,

or

when

CH.

1

is

in

the

playback

mode

and

CH.

2

in

the

recording

mode,

it

shall

be

50

Kc

+

6

Kc.

aa

Fig.

29

|

Take

the

measurement

in

the

recording

mode.

1.

Connect

the

100Q

Resistor

to

the

Record

Head

in

}

series.

2.

Measure

voltage

at

both

ends

of

the

100Q

Resistor:

and

obtain

the

bias

current

value.

13

:

Measured

Voltage

Blas

CANT

EN

5p

cletanceJGi00)

3.

The

Standard

Bias

Current

Value

shall

be

0.5

mA

+

0.05

mA.

But

when

the

adjustment

of

bias

current

is

required,

it

shall

be

more

than

0.4

mA.

ERASING

CURRENT

3.

The

Standard

Erasing

Current

shall

be

60

mA+20

Take

the

measurement

in

the

recording

mode.

1.

Connect

the

10Q

Resistor

to

the

Erase

Head

in

series.

-

:

cs

.

4.

When

taking

the

measurement

with

CH.

2

in

the

re-

=

>.

Measure

voltage

at

both

ends

of

the

10Q

Resistor,

cording

mode

and

CH.1

in

the

playback

mode,

and

obtain

the

current

value.

remove

the

Dummy

Coil

on

the

earth

side,

connect

the

Resistor

between

the

Dummy

Coil

and

the

earth,

:

F

Measured

Voltage

|

Erasing

Current

=

~

Resistance

(10)

and

take

the

measurement.

}

sondeucnconsaosuecss!

resaneuen

as:

eansansens

eusnnoecntananraquserse

sscausee

nena

jeoucas

seems!

mocncenapensssemsnncsnaawaneaoeasansnsessnsee’

ona

cues

asognaerses.

eawecassonesnssoumasseonssens|

nusooenst

maannsyascamyasusssasecssuenseseaerEaensee

|

i

ae

‘ .

Fig.

31

1.

Place

the

set

into

the

stereo

recording

mode,

stop

the

bias

oscillation,

and

adjust

the

Attenuator

so

that

|

say

0

VU.

|

re

the

recording

current

becomes

0.03

mA.

i

|

2.

Adjust

VR9

and

VR1O

so

that

the

level

meter

points

3.

The

measuring

frequency

shall

be

1

Kc.

14

RESISTORS

Ref.

No.

Description

R1,2...

Carbon

Resistor

R3,

4...

Carbon

Resistor

R5,

6

...

--.

Carbon

Resistor

R7,

8,

15,

16,

47,48

...

....

Carbon

Resirtor

RY,

10,

98,99

Carbon

Resistor

R11,

12,

94

Carbon

Resistor

R13,14,

23,24

Carbon

Resistor

R17,18

...

Carbon

Resistor

R19,

20,

29,

30,

91...

Carbon

Resistor

R21,

22

Carbon

Resistor

R25,

26

...

....

Carbon

Resistor

R27,

28,

35,

36,

45,

46,105

....

Carbon

Resistor

R31,

32

Carbon

Resistor

R33,

34

Carbon

Resistor

R37,

38

Carbon

Resistor

R39,

40

Carbon

Resistor

R41,

42

Carbon

Resistor

R43,

44

Carbon

Resistor

R49,

50

Carbon

Resistor

R51,52

...

Carbon

Resistor

R53,

54,61,62

Carbon

Resistor

R55,

56,

59,60

Carbon

Resistor

R57,

58,

63,64

Carbon

Resistor

R65,

66,

83,

84

Wire-wound

Resistor.

ATTENTION:

Parts

which

are

not

listed

are

part

of

an

assembly

and

are

not

stocked

as

a

separate

item.

To

obtain

parts

not

listed,

order

the

entire

assembly.

100

KQ

3900

22KQ

5.6KQ

10KQ

150Q

2.2KQ

12KQ

2.7KQ

6.8KQ

270KQ

4.7KQ

1.8KQ

27KQ

1KQ

479

3.3kKQ

470

3300

330

2700

560

1.2KQ

0.470

1/4W

1/4

1/4W

1/4

W

1/4W

1/4.W

1/4.

1/4W

1/4.W

1/4

1/4W

1/4.W

1/4W

1/4.W

1/4W

1/4.W

1/2

W

Part

No.

ERD-14TK104

ERD-14TK391

ERD-14TK223

ERD-14VK562

ERD-14VK103

ERD-14VK151

ERD-14VK222

ERD-14VK123

ERD-14VK272

ERD-14VK682

ERD-14VK274

ERD-14VK472

ERD-14VK182

ERD-14VK273

ERD-14VK102

ERD-14VK470

ERD-14VK332

ERD-14VK473

ERD-14VK331

ERD-14VK330

ERD-14VK271

ERD-14VK560

ERD-14VK122

ERW-12ROR47

ae

|

Ref.

No.

R67

RES

ees

eu

di:

R69,

70, 71,

72

R73,

74

R77

R78...

R79,

80

R81,

82

R85...

R87,

88

R89,

90

R92,

93

R95

RIE...

R100,

101

R102...

R103

...

R104...

VARIABLE

RESISTORS

VR1

VR2

...

VR3,

4

VR5,

6,7,8

VRQ,

10

Description

Carbon

Resistor

15KQ

1/4W

Carbon

Resistor

1.5KQ

1/4W

Solid

Resistor

10Q

1W

Carbon

Resistor

120Q

1/4W

Carbon

Resistor

560Q

1/4W

Carbon

Resistor

560Q

1/4W

Carbon

Resistor

1.8KQ

1/4W

Solid

Resistor

*

1002

1/2W

Carbon

Resistor

6.8KQ

1/4W

Carbon

Resistor

470KQ

1/4W

Carbon

Resistor

100KQ

1/4W

Carbon

Resistor

100Q

1/4W

Wire-wound

Resistor

1.5Q

1/2Ww

Solid

Resistor

68

1W

Solid

Resistor

180Q

1W

Solid

Resistor

270Q

2W

Fuse

Resistor

0.1A

8Q

Carbon

Resistor

272

1/4W

Volume

Control

5KQ-A

Volume

Contro!

5KQ-A

Tone

Control

20KQ-A

Gain

Adjustment

20

KQ-B

Level

Meter

Adjustment

2KQ-B

Part

No.

ERD-14VK152

ERD-14TK152

ERC-1GM100

ERD-14TK121

ERD-14VK561

ERD-14TK561

ERD-14TK182

ERC-12GM221

ERD-14VK682

ERD-14VK474

ERD-14VK104

ERD-14VK101

ERW-12R1R5

ERC-1GM680

ERC-1GM1B1

ERC-2GM2

ERU-2PC8R¥j

ERD-14TK270

EVC-B05L30A53

EVC-B9AL30A53

EVC-BOGL30A24

EVL-S3AA00B24

EVL-TOAAQOB23

_

91

CAPACITORS

Ref.

No.

C1,

2,5,

6,

21

29,

25, 26,

29.

S004

oe

C3,

4,

19,

20

..

C7,8

...

C9,

10

Cll,

12

C13,

14

C15,

16

C17,

18

C23,

24

C27,

28

C31,

32

C33,

34

C35,

36

..

«

C37,

38,

39,

40

C41,

42

C43,.44

C45.

C47,

48

C49,

50

C51.

C52,

53

C54

C55

C56

C57...

C59,

60

C61,

62

C63

C64,65

...

C66,

67,

68

C69,

70

Description

Electrolytic

Capacitor

Electrolytic

Capacitor

Electrolytic

Capacitor

Mylar

Capacitor

Mylar

Capacitor

Mylar

Capacitor

Electrolytic

Capacitor

Electrolytic

Capacitor

Electrolytic

Capabitor

Mylar

Capacitor

Polystyrene

Capacitor

Electrolytic

Capacitor

Electrolytic

Capacitor

Mylar

Capacitor

Electrolytic

Capacitor

Mylar

Capacitor

Mylar

Capacitor

Mica

Capacitor

Mica

Capacitor

Polystyrene

Capacitor

Mylar

Capacitor

—

Electrolytic

Capacitor

Electrolytic

Capacitor

Motor

Capacitor

Electrolytic

Capacitor

Electrolytic

Capacitor

Electrolytic

Capacitor

.

Mylar

Capacitor

Mylar

Capacitor

Paper

Capacitor

Mylar

Capacitor

VARIABLE

GAPAGCITORS.

VC1,2,3,4

Trimmer

Capacitor

°

3pF

10zF

50eF

0.00154F

0.022"F

0.00224F

50¢F

304F

50uF

0.047

#F

270

PF

100#F

220

uF

0.0047

pF

1000#F

0.0068F

0.012pF

90

PF

120

PF

1500

PF

0.1pF

504F

3000zF

uF

1004F

0.54F

304F

O.1eF

0.01

4F

0.14F

0.01

4F

Part

No.

“ECE-A15V3

ECE-A6V10

ECE-A6V50

ECQ-M05152MZ

ECQ-M05223KZ

ECQ-M05222MZ

ECE-A1L5V50

ECE-A6V30

ECE-A6V50

ECQ-M05473MZ

ECQ-S127

1KZ

ECE-A6V100

ECE-A25V220Z

ECQ-M05472MZ

ECE-Ai5V1000

ECQ-M05682MZ

ECQ-MO5123MZ

QCM-1D900K5

QCM-1D121K5

ECQ-S1152JZ

ECQ-MO5104MZ

ECE-A25V50

ECE-M25R3000B

MP-3000V2#

ECE-B250H100

ECE-AL5VOR5M

ECE-A15V30

ECQM1104M

ECN-R4104M

QCV-2013-1

woe

TRANSISTORS

Ref.

No.

Description

Trl,

2,

7,8

Transistor

.

Tr3,

4,

5.6

Transistor

Tr9,10,

11.12

Transister

Tr13,

14

...

Transistor

DIODE

&

RECTIFIERS

D1,2...

Diode

|

D3

Silicon

Rectifier

D4

Selenuim

Rectifier

THERMISTORS

THI,

2,

3,

4

Thermistor

|

THS

Thermistor

COIL

Ll

.

Erase

Head

Dummy

Coil

TRANSFORMERS

Tly.2

<2

Input

Transformer

T3,4...

Recording

Transformer

T5

Oscillator

Transformer

T6

Power

Transformer

SWITCHES

y

$1.2...

Record/Playback

Selector

Switch

_

$3

Forward/Reverse

Head

Selector

Switch

$4

Speed

Selector

Switch

$5

Stereo/Monaural

Selector

Switch

$6

Stop

Switch

_

$9

Speaker

ON/OFF

Switch

S11.

Automatic

Shut-off

Switch

$12

Motor

Selector

Switch

$14

Plunger

Switch

$16

Recording

Automatic

Stop

Switch

S17

FF

and

Rewind

Prevten

Switch

Part

No.

2SB

346

2SB

175A

2SB

473

2SB

324

OA

70

FR-1M

25F

QVM-300A

QVM-800B

QLH-9007

QLA-0118-1

QLA-0337

QLB-0128

QLP-0406

Qss-1021

QSS-100$

ESD-113

oss1014

QSs-1043;

Qss-1035

QSM-0016

QSS-1045

QSM-0014

QSB-0154

QSB-122

i

H

;

i

S

|.

H

4}

Ref.

No.

$18

$19

$21

$22

Description

Reverse

Prevent

Switch

Gain

Adjustment

Switch

Reverse

Switch

Forward

Switch

ELECTRICAL

PARTS

OWON

ANB

WH

10-2

LE?

Gy

11-1

U2

sax

a

140

15

16

17

18

19

..

20.

oF:

22

23

25

26

27

28

10-1

24.

VU

Meter-Left

VU

Meter-Righh

Record/Playback

Head

Erase

Head

Relay

Speaker

7-P

MT

Molded

Socket

7-P

Plug

(M)

RCA

Jack

Muniature

Jack

(M3-B)

Nut

for

Muniature

Jack

Washer

for

Muniature

Jack

Headphone

Jack

Nut

for

Headphone

Jack

‘Pilot

Lamp

Sock

Pilot

Lamp

Pilot

Lamp

Cover

Pilot

Lamp

Cover

AC

Power

Cord

HEYCO

Bushing

Heat

Sink

Circuit

Board

Assembly

(main)

Circuit

Board

Assembly

(equalization)

Circuit

Board

Assembly

(head

selector)

Circuit

Board

Assembly

(gain

adjustment)

.

2-P

Lug

Board

Lug

Board

with

Wire

Lug

Board

with

Wire

4-P

Lug

Board

3-P

Lug

Board

2-P

Lug

Board

Part

No.

QSB-154

QSS-1043

QSB-0162

QSB-0157

QSL-0028

QSL-0029

WY-411W

WY-504X

QSK-0110

EAS-18D28SB

QUS-701

QUP-0921

QJA-902

QJA-104-1

QNQ-1006

QWQ-1046

QJA-0216

‘QWQ-1035

QUS-101-1

QVL-101

QTV-1025

QTV-1010

QFC-1016F

QTD-1129

QTH-1028

QET-1051

QEE-1077

QEE-1078

QJT-4001-1

QJT-3003-1

QJT-2003-1

Description

5-P

Lug

Board

|

»-

4-P

Lug

Board

Wire

Spring

Wire

Cramper-A

_

Wire

Cramper-D

Shield

Plate

.

Lug

Terminal

AC

Power

Middle

Terminal

Nut

for

Volume

Control

Washer

for

Volume

Control

Spring

Washer

for

Volume

Control

Recording

Lever

Angle

Recording

Lock

Plate

Recording

Lever-1_

Recording

Lever-2

Recording

Slide

Plate

Recording

Lock*Plate

Guide

Switch.

Off

Lever

Recording

Switch

Arm-1

Recording

Switch

Arm-2

Spring

Hanger

(1.6¢x8)

Recording

Lever

Shaft

Recording

Arm

Shaft

Ping

Fiber

Plate

Recording

Arm

Spring-1

Assembly

Recording

Arm

Spring-2

Assembly

Recording

Lever

Spring

Recording

Slide

Spring

Assembly

Cord

Holder

Leaf

Switch

Holding

Plate

Front

Angle

Left

Jack

Angle

Right

Jack

Angle

..

Circuit

Board

Angle-A

Circuit

Board

Angie-B

Part

No.

QJT-5002

QJT-4002

QTD-1121

QTD-1002

QTD-1005

QTS-1079

QJT-0015

QBK-1053-1

QNQ-1004

Qwa-1008

Qwa-2002

QMA-1206

QMF-1205

~

QML-1419

QML-1420

QML-1421

QMA-1205

QML-1422

QML-1423

QML-1424

QMA-1170

QNP-116

x8U3

QMS-1318

QMS-1319

QMN-1173

QBK-1081

axJ-006¢:

@xJ.0061}

QBT-1259}/

QXJ-0062

'

QTD-1155

QMA-1207

QTT-1422

QTT-1423

QTT-1424

QTT-1379

QTT-3480

sl

Ref.

No.

66

67°

68

69

70

71

72

73

74

75

76

eee

78

79

80

Bia

ae

83

84

Description

Circuit

Board

Angle-C

Circuit

Board

Angle-D

Trimmer

Angle

Circuit

Board

Retainer

Transformer

Angle

Heat

Sink

Cord

Retainer

Capacitor’

Angle

Capacitor

Band

Protection

Cover

Relay

Holding

Plate

Capacitor

Cover

Pilot

Lamp

Holding

Stand-Right

Pilot

Lamp

Holding

Stand-Left

Jack

Plate-Right

Jack

Plate-Left

Jack

Indication

Plate-Right

Jack

Indication

Plate-Left

_.

Angle

for

Cord

Bushing

MECHANICAL

PARTS

101

102

102-1

102-2

102-3

102-4

-

102-5

102-6

103

104

105

106

107

108

109

110

Motor

Base

Plate

Assembly

Speed

Selector

Shaft

Angle

Assembly

speed

Selector

Shaft

Angle

Boss

Speed

Selector

Lever

Stop

Ring

E5¢

Click

Spring

Thrust

Ball

Spring

Washer

SW3¢

Screw

af

M3¢x6

Motor

Pulley-1

Assembly

Small

Screw

Motor

Pulley-2

Small

Screw

Belt

Shifter

Stopper

Spring

Washer

SW3¢

|

QTT-1427—

Part

No.

-

QTT-1425

QTT-1426

—

QTT-1428

QTT-1429

QTH-1036

QTT-1430

QTT-1431

QTT-1434

QTS-1099

QBJ-1232°

QBK-1080

QTT-1432

QTT-1433

QGJ-1085

QGJ-1096°

QGS-2130

QGS-2131

QTT-1314

QXK-1096

QXE-0021

QMA-1187

QMN-1180

©

QML-1413

QNS-504T3

QBP-1092

QDK-1003

Qws-302U3

QHM-230

x

6U3

QxP-0184

QHP-840

x

6U3

QDP-1178

QHP-840

x

6U3_

QMA-1186

—

Qws-302U3

Ref.

No.

111

112

113

115°

116

117

118

119

120

121

122

123

124

126

127

129

130

131

132

133

134-1

135

136

137

139°

;

140:

141

142°

143

144

145

146

114...

125

128

-

BA

38

138°...

Description

‘Screw

+M3¢x4

-

Belt

Shifter

~

Belt

Shifter

Bushing

~

Spring

Washer

SW3¢

Screw

+M3¢x

12.

(4G-37-M3)

Spring'Washer

SW3¢

Nut

N3¢

Equalizer

Switch

Lever

Switch

Spring

Plate

Aluminium

Rivet

26x

3

“Equalizer

Switch

Spring

Fiber

Washer

(5.2

x

10x0.5)

Stop

Ring

E4¢

Spring

Wastier

SW4¢

Screw

+M4¢x6

-

Fiber

Washer

Motor

Capacitor

Motor

:

Record/Playback

Head

Erase

Head

Erase

Head

Spacer

R/P

Head

Spacer

-

R/P

Head

Pad

Plate-Right

Assembly

Pad

Felt

R/FeHead

Pad

Shaft

R/P

Head

Pad

Plate-2

R/P

Head

Pad

Spring

R/P

Head

Pad

Plate-Left

Assembly

Erase

Head

Pad

Plate-Right

Erase

Head

Pad

Shaft

R/P

Head

Pad

Spring

Erase

Head

Pad

Plate-Left

_

R/P

Head

Holding

Plate

Erase

Head

Holding

Plate

Lock

Washer

Screw

2¢x3

oe

ZWERRERR

REO

Part

No.

QHM-230

x

4U3

QMF-1192

QBJ-1206

*

QWS-302U3

QHM:230:°x

12U3

QMN-1178

QWS-302U3

QMN:3022U3

QML-1400

QBP-1124.

QHM:720

x

30B4

QBT-1249

|

QBK-7027

QNS-404T3

QWS-402U3.-

QHM-230

4U3

MP-300V2#

AKC:20BPL:

WY-411W.

.

WY-504X

.

QBJ-1216-

QBJ-1215

QAP-1016

QAP-1127

QAP-1111

-

QAP-1018

QAP-1

of

QAP-101

;

QAP-1018

QAP-1152

QKT-1225

QKT-1226

QWwG-202K3

QHN-120

x

3U3

+

IAS

+

Sos

an

e

U

te

fs

Description

Screw

+M3¢x6

Screw

+S3¢x8

Spring

Washer

SW2¢

Screw

—2¢x5

Head

Spring

Plate

Tape

Guide

Pole-C

Tape

Guide

Spring

Tape

Guide

Washer

Limiter

Nut

N2.6¢

Spring

Washer

SW2.6¢

Nut

N2.6¢

Tape

Retainer-Left

Screw

+M2.6¢x

12

Tape

Retainer-Right

Contact

Pole

Contact

Lug

Lock

Washer

2.6¢

Nut

N2.6¢

Screw

—PH2.6¢x

14

Spring

Washer

SW2.6¢

Automatic

Shut-Off

Switch

Holding

Plate

Lock

Washer

3¢

Screw

—PH3¢x5

Fiber

Washer

5.2x10x0.25

Stop

Ring

E4¢

Shut-Off

Switch

Balance

Weight

Lock

Washer

3¢

Screw

xM3¢x6

Panel

Angle-Left

Spring

Washer

SW3¢

Panel

Angle-Right

Head

Switch

Arm

Fiber

Washer

5.2x10x0.25

Stop

Ring

E4g

Part

No.

QHM-230

x6U3

QHS-230

x

8U3

QWS-202U3

~

QHN-120

x

5U3

QBP-1126

QAG-1126

QBC-1087

QWQ-1085

QAG-1107

QNN-2622C1

QWS-262U3

QNN-2622U3

QMA-1189

QHM-266

x

12C1

QMA-1188

QMP-1126

QJT-1003

QWG-262K3

QNN-2622U3

QHN-126

x

14U3

QWS-262U3

QSM-0016

QMF-1201

QWG-302K3

QHN-130

x

5U3

QBK-7085

QNS-404T3

QMN-1171

QMN-1181

QWG-302kK3

QHM-230

x

6U3

QMA-1209

QWS-302U3

QMA-1208

QML-1392

QBK-7085

QNS-404T3

Ref.

No.

184

185

186

187

188

189

189-1

189-2

189-3

190

191

192

193

193-1

193-2

193-3

193-4

193-5

193-6

193-7

193-8

"193-9

193-10

193-11

193-12

193-13

194

195

196

197

198

199

200

201

202

203

-

204

Description

Tape

Shifter

Lever-1

Fiber

Washer

4.2x9x

0.25

Stop

Ring

E3¢

,

Tape

Shifter

Lever-2

Tape

Shifter

Holding

Plate

Assembly

Tape

Shifter

Assembly

Tape

Shifter

Pad

Shifter

Rivet

2¢x3

-

Spring

Washer

SW3¢

Screw

+M3¢x

4

Tape

Shifter

Spring

Reel

Table

Assembly

Reel

Upper

Plate

Ree!

Table

Reel

Table

Felt-2

Reel

Table

Pulley-1

Reel

Table

Spring

Polyethylene

Slider

Pulley

Pressure

Spring

.

Fiber

Washer

6.2x11x0.5

‘Stop

Ring

E5¢

Reel

Table

Slip

Felt

Reel

Table

Felt-3

Reel

Table

Pulley-2

Frittion

Spring

Idler

Lever

Assembly

Fiber

Washer

6.2x11x0.5

’

Stop

Ring

E5¢

Idler

Lever

Spring

idler

Arm

Assembly

Fiber

Washer

4.2x9x0.25

Idler

Felt

idler

Washer

Fiber

Washer

4.2x6x0.25

Stop

Ring

E3¢

Part

No.

QML-1401

QBK-7007

QNS-304T3

QML-1402

QAS-1035

QAS-1036

QHM-720

x

30B4

QWS-302U3

QHM-230

x

4U3

QXP-0185

QMF-1159

QDR-1041

QBF-1118

QDP-1169

QMF-1178

QBJ-3042

QBC-1082-1

QBK-7056

“QNS-504T3

‘QBF-1117

QBF-1119

QDP-1170

QBP-1123

QXL-014¢

QBK-700

ox

cp

QBT-1244,

QXA-0066

QBK-7007

QBF-1121

QWa-1023

QBK-7075

QNS-304T3

Panasonic RS-790S User manual

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