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INSTRUCTION

MANUAL

FOR

MODEL

467

CATHODE

RAY

TUBE

RESTORER/ANALYZER

DIVISION

OF

DYNASCAN

CORPORATION

1801

West

Belle

Plaine

Avenue

Chicago,

Illinois

60613

INSTRUCTION

MANUAL

S>K

PRECISION

INTRODUCTION

TABLE

OF

CONTENTS

ri

Page

.

INTRODUCTION

AND

SPECIAL

FEATURES.

3

SPECIFICATIONS

.

4

SAFETY

PRECAUTIONS

.

5

BRIEF

SUMMARY

OF

WHAT

THE

467

WILL

DO.

5

CONTROLS

AND

INDICATORS.

6

USING

THE

MODEL

467

..

9

Operation

.

9

Restoring

the

Picture

Tube

.

13

Cleaning,

Balancing

and

Rejuvenating.

14

HOW

THE

MODEL

467

WORKS

.

...

16

Emission

Test

..

16

Tracking

Test.

16

Leakage

Test.

16

life

Test.

20

Focus

Test

.

20

Shorts

Removal.

22

Cathode

Restoring

.

23

SERVICING

.

26

Field

Calibration.

26

SET-UP

CHARTS.

27

WARRANTY

INSTRUCTIONS..

.

28

WARRANTY.

28

THE

MODEL

467

USES

UNIQUE

TRIDYNAMIC®

APPROACH

The

Model

467

CRT

Restorer/Analyzer

has

been

designed

by

B

&

K-Precision

to

evaluate

most

television

picture

tubes,

computer

terminal

displays,

or

other

cathode

ray

tubes

with

a

high

degree

of

accuracy.

This

professional

quality

CRT

tester

utilizes

solid

state

digital

muliplexing

circuits

which

provide

new

testing

capabilities.

This

unique

TriDynamic®

approach

to

CRT

testing

makes

it

possible

to

test

all

types

of

CRT’s

—

even

Trinitrons

and

in-line

types

—

by

using

just

one

simple

test

procedure.

SPECIAL

FEATURES

Each

test

function

has

been

designed

to

provide

more

rapid

testing,

in

addition

to

reducing

human

error.

These

features

include;

1.

A

control

panel

which

guides

the

user

easily

through

the

correct

test

sequence.

2.

Three

precision

meters

that

display

emission

from

all

3

guns

simultaneously,

to

minimize

testing

time.

3.

Simultaneous

leakage

measurements

between

all

important

elements.

No

controls

to

adjust.

Even

cathode-to-cathode

leakage

can

be

detected.

4.

Heater

voltage,

G1

voltage,

and

line

voltage

are

precisely

and

simultaneously

indicated

on

the

three

meters.

5.

Continuously

variable

heater

voltage,

which

can

be

precisely

set

on

the

meter.

All

common

CRT

heater

voltages

are

premarked

on

the

meter

scale.

The

voltages

to

G1

and

G2

are

continuously

variable,

permitting

the

tube

to

be

checked

under

conditions

simulating

its

actual

use

in

the

receiver.

6.

New

color

tracking

feature

which

greatly

reduces

time

required

for

determining

proper

color

gun

tracking.

7.

A

new,

greatly

improved

rejuvenation

capability

is

provided

for

each

gun

independently.

The

entire

process

is

automatically

timed

and

operated

by

simply

depressing

the

RESTORE

button.

The

rejuvenate

feature

provides

maximum

cathode

restoration

while

at

the

same

time

minimizing

the

possibility

of

cathode

destruction.

8.

Simplified

automatic

life

test.

9.

Function

switching

between

rejuvenation

and

emission

test

permits

instant

evaluation

of

restoration

effectiveness.

10.

New,

improved,

more

versatile

adapter

set

is

included.

It

provides

capability

to

directly

test

more

CRT

types

with

fewer

adapters

than

any

other

currently

available

tester.

11.

Continuity

to

focus

electrodes

is

quickly

checked

by

the

simple

push

of

a

button.

12.

Short

indicator

lamp

shows

instantly

when

Gl-K

short

has

been

successfully

removed.

3

SPECIFICATIONS

TYPES

OF

CRT’S

TESTED:

Most

black

and

white

and

color

TV

picture

tubes,

video

monitors,

and

computer

terminal

CRT’s*

TESTS

PERFORMED:

Emission

Leakage

Tracking

(Color

Tubes)

Life

Focus

Continuity

RESTORING

FUNCTIONS:

Shorts

Removal

Gun

Cleaning

and

Balancing

Cathode

Rejuvenation

METERS:

(Three;

2W’;

D’Arsonval

movement*)

Meter

Indications:

Emission

(0-2mA)

Restoring

Current

(0-2

scale)

Heater

Voltage

(0-15V)

G1

Bias

Voltage

(30-100V)

Power

Line

Voltage

(100-130V)

TEST

VOLTAGES:

Heater:

0

-

7

@

2.0A

7-

14

@

600

mA

G1

Bias:

Neg.

30

to

Neg.

100

VDC

G2

Supply:

Normal,

0-350

VDC

High,

180-530

VDC

ACCESSORIES:

CRT

Socket

Adapters:

6

supplied;

optional

adapters

available

for

all

common

TV

picture

tubes.

Set-up

Chart:

Shows

adapter

number

and

test

voltages*

POWER

REQUIREMENTS:

117

VAC,

60

Hz,

40

Watts,

FUSES

(INTERNAL):

Heater

Supply

-

Type

3AG,

0.3A

Slo-Blo

High

Voltage

Supply

—

Type

3AG,

3/8A

Slo-Blo

CASE:

One-piece,

high-impact

polyethylene,

with

internal

cord

and

adapter

storage,

SIZE:

13W”

x

10”

x

5%”.

WEIGHT:

10

lbs.

4

SAFETY

PRECAUTIONS

1.

The

proper

power

line

supply

voltage

is

indicated

on

the

chassis

where

the

power

cord

enters

the

instrument.

Do

not

attempt

to

operate

this

instrument

from

a

power

source

other

than

specified.

2.

When

testing

any

CRT

that

is

installed

in

a

chassis,

first

disconnect

the

chassis

power

plug

from

the

AC

line

outlet

.

Do

not

apply

power

to

the

TV

chassis

at

any

time

during

the

test

of

a

CRT.

3.

Read

and

observe

the

“Test

Instrument

Safety”

recommendations

on

the

inside

front

cover

of

this

manual.

BRIEF

SUMMARY

OF

WHAT

THE

467

WILL

DO

The

Model

467

CRT

Restorer/Analyzer

will:

1.

Rapidly

test

a

cathode

ray

tube

for

satisfactory

emission.

2.

Restore

tubes

having

low

emission.

3.

Check

for

shorts

or

leakage

between

the

elements

in

the

tube,

and

also

indicate

between

which

elements

the

fault

exists.

4.

Check

relative

cathode

emission,

to

directly

and

rapidly

indicate

balance

(tracking)

between

the

guns

of

a

color

CRT.

5.

Check

the

life

expectancy

of

the

tube.

6.

Repair

the

most

common

shorts

in

cathode

ray

tubes:

those

between

cathode

and

Gl.

7.

Check

continuity

to

the

focus

electrode

of

the

gun(s).

5

CONTROLS

AND

INDICATORS

1.

Function

Switch:

2.

G2

Voltage

Range

Switch:

NORMAL

position

HIGH

position

3.

HTR

RANGE

Switch:

0

—

4

position

4

—

7

position

7

-

9

position

8-11

position

10-12

position

12

-

14

position

4.

SET

HEATER

Control:

5.

RED/B&W

meter:

6.

SET

G1

Control:

7.

GREEN

Meter:

8.

BLUE

Meter:

Selects

Main

Functions.

POWER

OFF

SET-UP

SET

CUTOFF

TEST

EMISSION

RESTORE

Selects

two

ranges

of

G2

supply

voltage.

0-

350

VDC

180-

530

VDC

Coarse

adjustment

of

heater

voltage.

0-4

VAC

@

2.0A

4-

7

VAC

@

2.0A

7-

9

VAC

@

0.6A

8-

1

1

VAC

@

0.6A

10-

12

VAC

@

0.6A

12-

14

VAC

@

0.6A

Fine

adjustment

of

heater

voltage

±2

VAC.

Reads

emission

of

red

gun

or

black

and

white

tube.

Reads

heater

volt¬

age

when

FUNCTION

SWITCH

(1)

is

in

SET-UP

position.

Adjusts

control

grid

bias

voltage

when

FUNCTION

SWITCH

(1)

is

in

SET-UP

position.

Reads

emission

of

green

gun.

Reads

value

of

Gl

bias

voltage

when

function

switch

is

in

SET-UP

position.

Reads

emission

of

blue

gun.

Reads

power

line

voltage

when

FUNC¬

TION

SWITCH

(1)

is

in

SET-UP

position.

6

9.

LEAKAGE

Lamps:

10.

G2

Control

-

RED

11.

G2

Control

-

GREEN

12.

G2

Control

—

BLUE

13.

TRACKING

Pushbutton:

TRACKING

Control:

14.

LIFE

Test

Pushbutton:

15.

FOCUS

Test

Pushbutton:

FOCUS

OK

Lamp:

16.

REMOVE

SHORTS

Pushbutton:

Gl-K

SHORTS

Lamp:

17.

REJUVENATE/CLEAN*BALANCE

Selector

Switch:

18.

19.

RESTORE

Pushbuttons:

20

.

21.

RESTORE

Ballast

Lamp:

22.

POWER

Lamp:

Indicates

leakage

from

cathodes

to

heater

or

Gl

and

between

cathodes

when

FUNCTION

SWITCH

(1)

is

in

SET-UP

position.

Adjusts

value

of

G2

voltage

to

SET

CUTOFF

condition

of

test.

Activates

tracking

adjustment

con¬

trol.

Simultaneously

varies

readings

of

the

three

emission

meters

(5,

7,

8,)

from

10%

to

90%.

Automatically

reduces

heater

volt¬

age

by

15%

from

the

value

set

on

meter

(5)

•

Activates

focus

electrode

continu¬

ity

test.

Indicates

continuity

from

CRT

base

pin

to

focus

electrode.

Discharges

capacitor

through

short

between

Gl

and

cathode.

Indicates

presence

of

short

circuit

between

Gl

and

cathode.

Selects

value

of

high

voltage

to

be

used

for

REJUVENATE

or

CLEAN^BALANCE

operation.

Applies

restoring

voltage

between

Gl

and

cathode,

and

simul¬

taneously

interrupts

heater

voltage.

Indicates

restoring

current

in

ballast

lamps.

Indicates

power

is

“on”.

7

USING

THE

MODEL

467

8

I

INTRODUCTION

\

The

following

procedure

describes

in

detail

the

use

of

the

467.

In

addition,

comments

and

notes

are

provided

regarding

the

significance

of

the

readings

to

aid

the

user

in

interpreting

the

measurements

obtained.

Because

of

the

unique

design

of

this

instrument,

all

tube

types

are

tested

in

the

same

manner

regardless

of

gun

structures.

After

the

user

has

become

thorpughly

familiar

with

the

instructions

and

the

instrument

itself,

he

will

need

only

to

refer

to

the

SET-UP

CHART

booklet.

HOW

TO

USE

THE

SET-UP

CHARTS

For

convenience,

color

and

black/white

CRT’s

are

grouped

separately.

In

each

group

the

tubes

are

listed

first

in

increasing

numerical

order

by

screen

size,

whether

in

inches

or

millimeters;

then

in

alphabetical

order,

by

the

letters

following

the

screen

size.

Foreign

tubes

having

alphabetical

prefixes

are

listed

at

the

end

of

the

listing

of

tube

types

having

numerical

prefix

identification.

OPERATION

(Refer

to

Control

Panel

Illustration)

A.

SET-UP:

1.

S

et

FUNCTION

Switch

(1)

to

the

OFF

position.

2.

Plug

the

Model

467

line

cord

into

a

convenient

power

outlet.

3.

Set

all

variable

controls

fully

counterclockwise.

4.

Locate

the

type

number

of

the

CRT

to

be

tested

in

the

SET-UP

CHART.

5.

Select

the

adapter

by

the

number

indicated

and

connect

it

to

the

adapter

cable.

6.

Place

the

G2

NORM/HIGH

(2)

in

the

NORM

position.

7.

Set

the

HTR

RANGE

Switch

(3)

to

the

range

which

includes

the

heater

voltage

shown

in

the

SET-UP

CHART.

8.

If

the

CRT

to

be

tested

is

mounted

in

the

TV

set,

make

sure

that

power

to

the

TV

set

is

removed,

preferably

by

unplugging

the

set.

A

shock

hazard

and

possibility

of

damage

to

the

467

exists

if

an

attempt

is

made

to

test

the

CRT

with

the

TV

set

operating.

9.

Connect

the

socket

adapter

to

the

base

of

the

CRT,

taking

care

to

align

keyway

properly.

10.

R

otate

the

function

switch

to

SET-UP

position.

9

11.

Carefully

adjust

the

SET

HTR

control

(4)

while

observing

the

HTR

•VOLTS

scale

of

the

RED/B&W

meter

(5)

for

the

heater

voltage

indicated

in

the

SET-UP

CHART.

For

convenience,

the

most

common

heater

voltages

are

precisely

marked.

12.

Adjust

the

SET

G1

control

(6)

while

observing

the

G1

VOLTS

scale

of

the

GREEN

meter

(7)

until

the

meter

indicates

the

value

of

G1

specified

in

the

SET-UP

CHART.

(50V

unless

indicated

by*.)

13.

The

LINE

VOLTS

scale

on

the

BLUE

meter

(8)

automatically

monitors

line

voltage

present

at

the

time

of

the

test

while

the

FUNCTION

switch

is

in

the

SET-UP

position.

This

may

be

helpful

in

diagnosing

some

symptoms

related

to

low

line

voltage.

For

example,

a

marginal

picture

tube

might

perform

very

poorly

with

low

line

voltage

because

of

the

reduced

heater

voltage.

B.

L

EAKAGE

TEST:

With

the

FUNCTION

switch

in

the

SET-UP

position,

observe

the

five

LEAKAGE

lamps

(9).

When

glowing,

these

lamps

automatically

indicate

leakages

between

cathodes,

or

from

any

cathode

to

the

heater

or

to

Gl.

For

example,

if

the

KB,

KR,

and

Gl

lamps

glow,

it

is

an

indication

of

leakage

between

the

blue

cathode,

the

red

cathode,

and

the

control

grid.

Only

those

elements

which

have

leakage

between

them,

in

the

order

of

2

megohms

or

less,

will

be

indicated

by

the

lamps

glowing.

NOTE

If

the

leakage

lamps

glow

very

faintly,

even

though

the

CRT

tests

normal

in

all

other

functions,

the

cause

may

be

dirt

or

other

contamination

between

the

tube

base

pins.

This

can

usually

be

ignored.

Heater-Cathode

Leakage:

Leakage

between

heater

and

cathode

cannot

be

repaired.

When

such

leakage

is

determined

to

be

the

cause

of

set

malfunction,

it

is

necessary

to

replace

the

picture

tube.

If

the

TV

heater

power

source

permits

the

use

of

an

isolating

transformer,

its

use

mfay

restore

normal

operation.

Cathode-to-Cathode

Leakage:

Excessive

leakage

between

cathodes

can

some¬

times

result

in

TV

set

malfunction.

Such

leakage

cannot

be

repaired.

Grid-to-Cathode

Leakage:

Excessive

leakage

or

a

short

between

the

control

grid

and

cathode

is

a

common

fault

in

picture

tubes.

Any

current

path

below

two

megohms

will

light

the

Gl-K

LEAKAGE

lamp

(16).

Shorts

and

leakage

paths

below

20k

ohms

will

also

light

the

Gl-K

SHORTS

lamp

when

the

function

switch

is

in

the

RESTORE

position.

If

only

leakage

is

indicated,

restore

the

tube

by

using

the

CLEAN»BALANCE

procedure;

if

a

Gl-K

short

exists,

use

the

REMOVE-SHORTS

procedure

(see

“RESTORING

THE

PICTURE

TUBE”).

10

C.

S

E

T

CUT-OFF:

1.

Rotate

the

FUNCTION

Switch

to

the

SET

CUT-OFF

position.

The

3

meters

should

read

zero

or

slightly

above

or

below

zero.

2.

Slowly

advance

each

of

the

three

G2

controls

(10),

(11),

and

(12)

clockwise

until

the

corresponding

meter

rises

one

small

division

of

the

meter

scale.

This

adjustment

sets

the

G2

voltage

at

the

value

for

spot

cut-off

of

each

color

gun.

If

a

tube

or

gun

cannot

be

brought

out

of

cut-off

by

advancing

the

G2

control

fully

clockwise,

place

the

G2

NORM/HIGH

switch

(2)

in

the

HIGH

position.

NOTE

For

black

and

white

tubes,

use

only

the

RED

G2

control.

Make

sure

the

others

are

turned

fully

counterclockwise.

D.

EMISSION

TEST:

Rotate

the

FUNCTION

Switch

to

the

TEST

position.

The

three

meters

will

indicate

the

cathode

emission

current

for

each

of

the

three

electron

guns.

In

some

instances,

the

meters

may

read

somewhat

beyond

the

full

scale

deflection.

This

indicates

that

the

tube

has

excellent

emission.

A

greater

than

full

scale

reading

will

not

in

any

way

damage

the

instrument.

In

some

cases,

the

current

may

rise

to

approximately

Vi

or

%

scale

and

then

slowly

decrease.

Evaluation

of

emission

should

be

made

when

the

readings

have

stabilized.

In

all

cases,

if

the

emission

readings

stay

well

within

the

green

(GOOD)

area,

the

emission

characteristics

of

the

tube

may

be

considered

acceptable.

If

emission

reads

in

the

red

(BAD)

area,

proceed

to

REJUVENATE

(see

“RESTORING

THE

PICTURE

TUBE”).

E.

TRACKING

TEST:

1.

With

the

FUNCTION

Switch

in

the

TEST

position,

depress

and

hold

the

TRACKING

pushbutton

(13),

2.

With

TRACKING

button

depressed,

rotate

the

TRACKING

knob

(13)

so

that

the

pointer

of

the

highest

reading

meter

coincides

with

the

SET

TRACKING

LINE

located

at

the

high

end

of

the

yellow

wedge

on

the

meter

scale.

3.

Observe

the

other

two

meters

and

note

if

the

readings

are

within

the

yellow

tracking

wedges

on

each

meter.

If

all

three

pointers

are

within

the

yellow

wedges,

the

tracking

ratio

of

the

CRT

is

acceptable.

If

the

tube

does

not

track,

proceed

to

CLEAN®BALANCE

(see

“RESTORING

THE

PICTURE

TUBE”).

4.

When

the

TRACKING

button

is

released,

the

three

meters

immediately

will

return

to

the

original

emission

readings

that

were

obtained

in

the

emission

test.

The

tracking

pushbutton

may

be

depressed

as

often

as

desired

without

affecting

the

calibration

of

the

emission

readings.

F.

LIFE

TEST:

1.

With

the

FUNCTION

Switch

in

the

TEST

position,

depress

and

hold

the

LIFE

pushbutton

(14)

and

allow

the

emission

readings

to

stabilize.

For

acceptable

long

term

CRT

performance,

the

readings

should

stay

in

the

green

(GOOD)

area.

The

less

the

emission

drops,

the

longer

the

life

expectance

of

the

tube.

2.

While

holding

down

the

LIFE

button,

depress

the

TRACKING

button

and

perform

the

TRACKING

test

of

Step

E.

For

acceptable

long-term

performance,

the

CRT

should

maintain

tracking

with

the

LIFE

test

button

held

down.

3.

Release

the

LIFE

and

TRACKING

buttons.

4.

If

life

expectancy

is

poor,

proceed

to

CLEAN«BALANCE.

NOTES

Other

clues

for

judging

life

expectancy

are

obtained

by

observing

the

“warm-up”

and

“cool-off’

behavior

of

the

cathode.

To

make

these

observations

in

the

TEST

position,

press

any

RESTORE

pushbutton

(18,

19,

20).

This

interrupts

the

heater

circuit

and

makes

it

possible

to

observe

the

rate

at

which

the

emission

rises

and

falls

as

the

cathode

heats

up

and

cools

down.

Since

the

emission

from

all

three

guns

of

a

color

CRT

is

displayed

simultaneously,

significant

differences

between

cathodes

are

easily

observable.

If,

for

instance,

during

warm-up,

one

gun

reaches

full

emission

much

slower

than

the

other

two,

it

is

an

indication

that

there

may

be

very

little

good

material

left

on

that

cathode

or

that

its

heater

has

been

dislodged

away

from

the

cathode

causing

lower

than

normal

cathode

temperature.

In

either

instance,

it

is

a

further

indication

that

short

life

may

be

expected

from

that

gun.

A

good

tube

will

reach

full

emission

levels

and

will

track

within

two

minutes.

Similarly,

the

“cool-off’

characteristic

can

provide

another

clue

for

judging

life

expectancy.

Observe

the

time

it

takes

for

emission

from

each

gun

to

fall

after

the

heater

voltage

is

interrupted.

If,

for

instance,

two

guns

maintain

full

emission

for

7

to

10

seconds,

and

the

third

gun

falls

rapidly

after

3

or

4

seconds,

short

life

can

be

expected

from

that

gun.

G.

FOCUS

ELECTRODE

CONTINUITY

TEST:

With

the

FUNCTION

Switch

in

the

TEST

position,

depress

the

FOCUS

pushbutton

(15).

Observe

the

FOCUS-OK

lamp

(15).

If

the

FOCUS-OK

lamp

glows

or

flickers,

the

focus

electrode

continuity

to

the

tube

base

pin

is

good.

12

i

i

I

NOTE

It

is

also

possible

to

check

for

an

open

interconnection

in

color

CRT

s,

with

individual

focus

electrodes

that

are

internally

connected

by

welded

straps.

To

do

this,

push

the

FOCUS

test

button

and

observe

the

3

emission

readings

on

the

meters.

If

all

3

meter

readings

drop

approximately

the

same

amount,

the

inter-electrode

continuity

is

good.

If

one

or

two

meter

readings

drop

slightly

whil^

the

other

drops

to

near

zero,

there

is

no

continuity

to

the

focus

electrode

of

the

low

reading

gun,

even

though

the

FOCUS-OK

lamp

glows.

If

the

tube

tests

bad

for

focus

continuity,

a

decision

to

replace

the

tube

should

be

based

on

actual

performance

in

the

TV

set.

If

the

focus

is

not

objectionable

to

the

customer,

the

CRT

need

not

be

replaced.

RESTORING

THE

PICTURE

TUBE

The

Model

467

employs

three

restoring

functions:

REMOVE

SHORTS,

CLEAN*BALANCE,

and

REJUVENATE.

All

three

are

available

in

the

RESTORE

position

of

the

function

switch.

LEAKAGE

AND

SHORTS:

Excessive

leakage

or

a

short

between

the

control

grid

and

cathode

will

show

up

in

the

LEAKAGE

test

that

is

automatically

performed

during

SET-UP.

A

low

resistance

short

(less

than

20k

ohms)

can

be

removed

by

the

REMOVE

SHORTS

procedure.

High

resistance

leakage

is

most

successfully

removed

by

the

CLEAN*BALANCE

procedure.

If

grid-to-cathode

leakage

was

indicated

in

the

LEAKAGE

test

during

SET-UP,

use

the

following

procedure.

A.

REMOVE

SHORTS:

1.

Set

the

FUNCTION

SWITCH

to

the

RESTORE

position.

2.

Observe

the

Gl-K

lamp

(16).

If

it

is

not

glowing,

a

high

resistance

leakage

is

indicated;

use

the

CLEAN»BALANCE

procedure.

3.

If

the

Gl-K

lamp

glows,

push

the

REMOVE

SHORTS

button

(16)

and

release.

If

the

short

has

been

successfully

removed,

the

lamp

will

not

glow.

4.

If

the

lamp

continues

to

glow,

repeat

Step

3

several

times.

Wait

5

to

10

seconds

between

operations.

If

the

short

has

not

been

successfully

removed,

reduce

the

heater

voltage

by

turning

the

HTR

RANGE

(3)

switch

to

the

lowest

range.

If

the

Gl-K

shorts

lamp

goes

out

as

the

cathode

cools,

it

indicates

that

the

short

may

be

due

to

mechanical

expansion

of

the

cathode.

Such

shorts

usually

cannot

be

removed.

5.

After

the

short

is

removed,

resume

the

testing

procedure.

13

NOTE

One

or

more

LEAKAGE

lamps

may

glow

temporarily

if

the

FUNCTION

switch

remains

in

RESTORE

position

for

longer

than

15

seconds.

Also,

if

returning

to

SET-UP

to

re-check

leakage,

wait

at

least

one

minute

to

get

a

true

leakage

indication.

CLEANING,

BALANCING

AND

REJUVENATING

Cleaning

and

balancing

is

a

low

energy

restoring

operation.

It

can

be

used

safely

on

all

tubes

to

eliminate

surface

contamination

causing

high

resistance

leakage

or

for

further

improving

the

emission

of

a

fairly

good

cathode

to

restore

tracking

or

increase

life

expectancy.

Rejuvenation

is

a

higher

energy

procedure

for

restoring

cathodes

when

the

emission

is

below

usable

levels.

High

level

rejuvenation

of

one

gun

can

occasionally

reduce

the

previous

emission

reading

of

another

gun,

particularly

if

that

gun

had

just

been

rejuvenated.

Therefore,

after

rejuvenation,

it

is

often

desirable

to

“touch-up”

by

cleaning

and

balancing

one

or

more

of

the

guns

in

order

to

achieve

good

tracking.

B.

CLEAN«BALANCE:

1.

Set

the

FUNCTION

Switch

to

the

RESTORE

position

and

the

REJU-

VENATE/CLEAN.BALANCE

Switch

(17)

to

CLEAN*BALANCE.

Wait

20

to

30

seconds.

Observe

the

CRT

heater

for

increased

brightness

from

the

higher

heater

voltage.

2.

Push

and

hold

the

RESTORE

button

(18),

(19),

or

(20)

for

the

gun

to

be

cleaned

or

balanced.

The

meter

should

rise

immediately

to

a

value

near

midscale.

After

several

seconds

or

more,

depending

upon

the

condition

of

the

cathode,

the

pointer

will

begin

to

fall.

It

usually

will

fall

smoothly

to

some

low

value.

3.

Release

the

RESTORE

button

when

the

pointer

reaches

0.2.

If

the

pointer

drops

erratically

and

then

“hangs

up”

at

a

reading

greater

than

0.2,

wait

several

seconds

and

then

release

the

RESTORE

button.

Also,

observe

the

Gl-K

SHORT

lamp.

If

it

is

glowing,

remove

the

short

before

proceeding

further.

4.

Return

the

FUNCTION

Switch

(1)

immediately

to

SET-UP

(if

LEAKAGE

was

being

removed),

or

to

TEST

(if

balancing

or

“touch

up”

was

being

done).

Resume

testing.

5.

If

the

CLEAN*BALANCE

procedure

was

not

successful

and

the

condition

of

the

CRT

is

still

unsatisfactory,

use

the

REJUVENATE

procedure.

C.

REJUVENATE:

1.

Set

the

FUNCTION

Switch

(1)

to

the

RESTORE

position.

Set

the

REJUVENATE/CLEAN«BALANCE

Switch

(17)

to

REJUVENATE.

Wait

20

to

30

seconds.

2.

Push

and

hold

the

RESTORE

BUTTON

(18),

(19),

or

(20)

for

the

gun

to

be

rejuvenated.

The

pointer

immediately

will

rise

to

about

3

A

scale

and

the

RESTORE

ballast

(current

limiting)

lamp

(21)

will

glow

brightly.

After

several

seconds,

the

pointer

will

begin

to

fall.

Often

the

pointer

will

fall

erratically

or

hesitate

near

midscale

and

then

rise

slightly

before

continuing

to

fall.

This

behavior

is

usually

accompanied

by

observable

sparking

and

Sputtering

action

between

the

grid

and

cathode.

3.

Release

the

RESTORE

button

when

the

pointer

reaches

0.4

or

just

as

it

crosses

into

the

red

area

of

the

meter.

If

the

emission

does

not

fall

to

0.4

after

several

seconds,

release

the

RESTORE

button

immediately.

Observe

the

Gl-K

SHORTS

lamp

(16)

to

see

if

a

short

was

created

by

the

rejuvenation

process.

If

a

short

exists,

use

the

REMOVE

SHORTS

procedure.

4.

Return

to

TEST.

Allow

time

for

readings

to

stabilize.

A

rapid

judgment

of

relative

improvement

can

now

be

made.

For

greater

accuracy,

repeat

SET-CUTOFF.

5.

Repeat

LIFE

and

TRACKING

tests.

If

slight

further

improvement

is

needed,

or

if

rejuvenation

caused

lower

emission

from

one

of

the

other

guns,

use

the

CLEAN*BALANCE

procedure.

6.

If

the

CLEAN»BALANCE

procedure

after

rejuvenation

does

not

give

the

necessary

improvement,

repeat

REJUVENATE.

Most

cathodes

will

achieve

90%

or

more

of

the

possible

improvement

in

a

single

operation.

Some

will

require

two

or

three

cycles

of

rejuvenation

for

maximum

improvement.

Further

rejuvenation

generally

causes

lower

emission

and

shorter

life.

The

fewer

rejuvenation

cycles

that

are

used

to

achieve

satisfactory

emission,

the

greater

will

be

the

life

expectancy.

NOTES

If

the

meter

pointer

does

not

rise

when

the

RESTORE

button

is

pushed,

it

indicates

that

successful

rejuvenation

is

probably

not

pos¬

sible.

If

the

reason

for

lack

of

emission

is

an

extremely

inactive

(con¬

taminated)

cathode,

it

is

sometimes

possible

to

start

the

rejuvena¬

tion

process

by

applying

even

higher

heater

voltage

than

normally

used

for

rejuvenation.

To

try

this,

go

back

to

SET-UP

and

increase

the

heater

voltage

approximately

25%

above

the

normal

setting

(8.0V

for

6.3V

tubes).

Then

return

to

RESTORE

and

attempt

rejuvenation.

Since

the

tube

is

not

useful

anyway,

the

risk

is

small.

The

greatest

danger

is

that

excessive

heater

voltage

will

expand

the

cathode

so

far

that

a

short

to

G1

will

be

created.

Also,

of

course,

the

heater

itself

could

be

burned

open

by

the

higher

voltage,

although

this

occurs

less

frequently

than

a

short.

If

all

three

guns

show

initial

low

emission

(BAD),

rejuvenation

of

one

gun

will

often

result

in

some

improvement

of

the

other

two

guns.

(This

is

caused

by

the

elevated

heater

voltage

which

is

a

mild

form

of

rejuvenation

in

itself.)

These

guns

should

also

be

reju¬

venated,

however,

even

though

the

emission

may

have

been

improved

enough

so

they

read

in

the

GOOD

region.

14

15

HOW

THE

MODEL

467

WORKS

EMISSION

TEST

The

multiplex

test

method

(Patent

Applied

For)

employed

in

the

DYNASCAN

Model

467

tests

the

three

guns

in

a

rapid-fire

sequence,

on

a

1/3

duty

cycle

time-share

basis

(Fig.

1).

Each

gun

is

pulsed

20

times

per

second

and

the

peak

current

of

each

gun

is

continuously

indicated

on

its

individual

meter.

The

current

indicated

is

“true”

beam

current

-

that

is,

only

the

current

passing

through

the

G1

aperture.

A

GOOD

emission

indication

on

the

meter,

therefore,

assures

that

(given

the

high

voltage),

the

gun

is

capable

of

producing

adequate

highlight

brightness

on

the

face

of

the

picture

tube.

The

G2

voltage

is

supplied

by

a

digitally

programmed

regulator

so

that

it

can

be

automatically

adjusted

to

the

G2

cutoff

value

of

each

gun,

during

the

gun’s

test

interval.

This

is

why

the

test

set-up

and

procedure

is

the

same

for

even

those

tubes

that

have

a

common

connection

to

all

three

G2

elements.

TRACKING

TEST

The

multiplex

system

greatly

simplifies

the

tracking

test

(Fig.

2).

The

1

Vi

to

1

limit

for

emission

between

the

highest

and

lowest

guns

is

checked

by

showing

this

ratio

on

the

meter

scale

as

a

yellow

wedge

extending

upward

from

the

GOOD-BAD

limit

line.

The

TRACKING

control

changes

all

three

meter

readings

by

the

same

percentage

so

that

if

all

three

pointers

can

be

placed

in

the

yellow

area,

you

know

the

guns

are

tracking.

Changing

the

three

meter

readings

by

exactly

the

same

percentage

is

accomplished

electronically

by

changing

the

duration

of

each

test

interval

exactly

the

same

amount.

Thus,

if

each

gun

is

on

for

only

1/6

instead

of

1/3

of

the

time,

each

meter

reads

50%

of

its

former

value.

LEAKAGE

TEST

The

multiplex

system

simplifies

the

leakage

test

(Fig.

3).

Like

the

limit

used

to

make

a

GOOD-BAD

judgement

of

emission,

a

leakage

limit

somewhat

higher

than

the

manufacturer’s

limit

for

a

new

tube

is

used

-

a

limit

at

which

you

might

expect

trouble

to

begin

showing

up

in

a

typical

TV

set.

Fortunately,

such

a

leakage

limit

is

just

high

enough

to

cause

a

neon

lamp

to

glow.

By

using

a

group

of

5

lamps

(one

for

each

cathode,

one

for

the

heater,

and

one

for

Gl),

and

multiplexing

the

test

circuit,

we

can

observe

leakage

between

any

two

cathodes

or

from

any

cathode

to

the

heater

or

Gl.

(Both

lamps

will

glow,

showing

which

two

elements

are

involved.)

This

test

is

made

automatically

with

the

function

switch

in

the

SET-UP

position

and

requires

no

operator

adjustment.

It

will

detect

almost

any

leakage

problems

that

do

occur,

including

those

troublesome

cathode-to-cathode

leaks.

Fig.

1.

Emission

test

circuit

(simplified).

C>

RED

CATHODE

I

t

I