Tektronix 567 User manual

INSTRUCTION

MAN

UAL

Tektronix,

Inc.

Serial

Number

TYPE

567

READOUT

OSCILLOSCOPE

S.W.

Millikan

Way

@

P.

O.

Box

500

@

Beaverton,

Oregon

97005

®

Phone

644-0161

@

Cables:

Tektronix

070-0322-01

965

ype

and

Serial

nu

for

baeeen

i

SECTION

1

CHARACTERISTICS

General

Information

The

Tektronix

Type

567

Readout

Oscilloscope

is

the

power

supply

and

indicator

unit

for

a

complete

system

that

provides

digital

readout

of

signal

information.

The

two

smaller

plug-in

cells

accept

any

of

the

Tektronix

2

or

3

Series

plug-in

units.

The

large

plug-in

cell

accepts

the

Tektronix

6

Series

digital

units.

The

digital

units

are

com-

patible

with

some

(but

not

all)

of

the

2

or

3

Series

units.

See

your

Tektronix

Field

Engineer

for

details.

Without

the

digital

unit,

the

Type

567

will

operate

in

the

normal

oscillo-

scope

manner.

With

the

digital

unit,

the

system

can

readout

its

own

display

of

risetime,

amplitude

or

time

difference

for

either

conventional

voltage-time

displays

or

sampling

equiva-

lent-time

displays.

The

system

provides

“go,

no-go"

signals,

and

can

be

programmed

automatically

using

up

to

three

Tektronix

Type

262

Programmers.

ELECTRICAL

CHARACTERISTICS

Power

Supplies

Electronically

regulated

for

stable

operation

with

widely

varying

line

voltages

and

loads.

Line

voltage

requirements—105

to

125

volts,

or

210

to

250

volts,

rms,

50

to

60

cps,

single-phase

ac.

Power—Approximately

400

watts

when

using

the

Type

3876,

3177

and

6R1A

Plug-in

Units.

Fuse—4

Amp

Fast-Blow

for

117

volts,

2

Amp

Fast-Blow

for

234

volts.

Cathode-Ray

Tube

Type—T5032-2-1

(S/N

1999-up}

5610-31

(S/N

750-1998}

T5031-2

{S/N

101-749)

Phosphors—Standard

phosphors

as

listed

above,

others

available

as

listed

with

accessories

at

end

of

this

section.

Unblanking—Deflection

type,

de

coupled.

Accelerating

potential—Approximately

3.5

kv.

Usable

viewing

area—8

divisions

vertical

by

10

divisions

horizontal.

Deflection

plate

deflection

factors

(nominal

at

3.5

kv)

(S/N

1999-up

(S/N

101-1998}

19.5

volts/div

22.8

volts/div

Horizontal—18.4

volts/div

18.4

volts/div

Vertical—

Graticule

Internal

within

ert

(S/N

1999-up)

External

plastic

(S/N

101-1998}

®1

I{lumination—Variable

edge

lighting.

Markings—Marked

in 8

vertical

and

10

horizontal

1-centi-

meter

divisions

with

2-millimeter

markings

on

the

centerlines.

Amplitude

Calibrator

(S/N

2060-up).

A

square

wave

with

accurate

time

duration

and

amplitude;

intended

for

use

when

setting

the

vertical

and

horizontal

plug-in

units

front-panel

calibrate

controls.

Two

output

frequencies,

an

accurate

20

kc

and

an

approximate

1

kc.

The

1-kc

square

wave

is

valuable

when

adjusting

low-frequency

attenuator

probes.

Output

Voltage—Separate

BNC

connectors

produce

ground-referenced

0.5

and

5

volts

peak

to

peak

when

loaded

(one

or

both

at

the

same

time)

by

100k

or

greater.

Same

connectors

provide

50

and

500

mv

peak

to

peak

when

loaded

{one

at

a

time)

by 50

ohms.

Accuracy—Voltage

accurate

to

--2%

peak

to

peak

into

100k

or

greater

loads.

Voltage

accuracy

into

502

depends

on

load

resistor:

-—-2%

peak

to

peak

when

50

is

within

1%

at

one

output

connector

at

a

time.

Frequency

of

20-kc

square

wave

is

within

0.1%

when

the

l-ke

square

wave

is

within

+80%

and

—40%;

symmetry

not

specified

for

either

frequency.

+Pre

Trigger—A

short-duration,

ground-referenced,

posi-

tive

pulse

at

least

600

mv

peak

to

peak

into

100k

or

greater,

that

occurs

approximately

1%,

cycle

ahead

of

each

plus

rise

of

square-wave

signal.

Amplitude

is

reduced

by

502

load,

but

+Pre

Trigger

signal

is

intended

for

externally

triggering

the

time-base

units

of

sampling

systems

not

employing

an

internal

trigger

pickoff.

All

three

output

connectors

of

the

Amplitude

Calibrator

are

short-circuit

proof.

External

short

circuits

will

not

damage

the

calibrator

circuits.

(S/N

101-299).

Waveform—Square

waves

at

line

fre-

quency.

Output

Voltage—0.05,

0.5,

5

and

50

volts,

peak

to

peak

into

1

meg

or

greater

load,

one

at

a

time.

Accuracy—Peak-to-peak

amplitude

of

square

waves

within

3%

of

indicated

voltage.

(S/N

300-2059).

Above

characteristics

plus

100-mv

peak-to-peak

square

wave

available

from

0.5

jack

when

loaded

with

1%

509.

Ventilation

Forced,

filtered

air.

A

thermal

relay

interrupts

instrument

power

in

the

event

of

overheating.

Fan

remains

on

if

thermal

relay

opens

during

117-volt

operation.

Fan

turns

off.

if

thermal

relay

opens

during

234-volt

operation.

Temperature

of

the

thermal

relay

must

drop

about

15°

F

before

power

will

be

restored.

1-1

Characteristics—Type

567

MECHANICAL

CHARACTERISTICS

The

Type

567

is

constructed

with

aluminum-alloy

chassis

and

cabinet.

Cabinet

is

finished

with

a

durable

blue

vinyl

plastic.

The

unit

sits

on

short

anti-slide

neoprene

feet.

Cabinet

dimensions—Height

135/,”,

width

17”,

depth

23”.

Accessories

Information

on

accessories

for

use

with

this

instrument

is

included

at

the

rear

of

the

mechanical

parts

list.

®i

SECTION

2

OPERATING

INSTRUCTIONS

General

Information

The

Type

567

is

a

specially

designed

oscilloscope

for

producing

digital

display

of

information which

can

be

obtained

only

from

the

crt

on an

ordinary

oscilloscope.

The

digital

readout

system

can

be

made

to

display

either

voltage

or

time,

and

may

be

used

for

such

applications

as

measuring

the

peak-to-peck

amplitude

of

a

waveform,

or

its

risetime.

IF

dual-trace

plug-in

units

are

used

with

the

Type

567,

the

digital

readout

system

can

be

used

to

obtain

both

voltage

and

time

measurements

on

either

trace,

In

addition,

the

digital

readout

system

will

make

time

measurements

between

signals

displayed

on

one

trace

and

signals

displayed

on

the

other.

The

Type

567

and associated

units

are

relatively

easy

to

operate

once

the

basic

operating

procedures

are

understood.

It

is

the

purpose

of

this

section

ond

similar

sections

in

the

plug-in

unit

manuals

to

establish

the

proper

operating

tech

niques. This

manual

covers

instructions

for

the

Type

567

‘only.

For

operating

instructions

for

the

plug-in

units,

refer

to

the

applicable

instruction

manuals.

Preliminary

Instru

Before

operating

the

Type

567,

a

suitable

location

for

the

instrument

must

be

chosen. The

location

should

provide

a

stable

support

for

the

instrument.

Care

should

be

taken

that

adequate

air

circulation

is

permitted

through

the

instrument

by

keeping

it

away

from

walls,

or

from

other

equipment

which might

block

the

air

intake

through

the

filter

or

the

exhaust

passages

in

the

cabinet.

If

the

flow

of

air

over

the

components

in

the

unit

is

interrupted,

overheating

of

the

instrument

may

cause

a

thermal

relay

in

the

instrument

to

open,

shutting

down

the

instrument.

ns

The

Type

567

Oscilloscope

can

be

operated

from

110,

117,

or

124

volts,

or

220,

234,

or

248

volts.

The

only

changes

necessary

to

convert

from

one

operating

voltage

to

another

are

in

the

wiring

of

the

power

transformer

primary

and

the

fan

motor.

The

power

transformer

used

in

the

Type

567

Uses

two

separate

primary

windings

plus

two

6%

boost-buck

windings.

The

primary

windings

are

connected

in

parallel

for

117-volt

operation

and

in

series

for

234-volt

operation:

Proper

connections

for

each

line

voltage

are

shown

on

the

side

of

the

power

transformer

and

on the

Power

Supply

schematic.

A

small

metal

tag

near

the

power

receptable

at

the

rear

of

the

instrument

indicates

the

line

voltage

for

which

the

instrument

was

wired

at

the

factory.

If

wired

for

117

volts,

the

instrument

will

operate

properly

with

line

voltages

be-

tween

approximately

105

and

125

volts.

If

wired

for

234

volts,

the

instrument

will

operate

properly

from

approximately

210

to

250

volts.

Jo

change

the

power

transformer

connections

for

opera:

tidn

on

another

line

voltage,

change

the

location

of

the

bare

wire

straps

at

the

primary

terminals,

It

is

not

necessary

to

move

any

of

the

plastic

insulated

wires.

Place

the

new

straps

in

accordance

with

the

markings

on

the

tag

located

fon

the

power

transformer

side.

When

a

suitable

location

has

been

chosen,

set

the

POWER

ON

switch

to

the

off

position

and

connect

the

instrument

to

{an

appropriate

source

of

power.

Place

the

desired

vertical

plugin

unit

(for

example,

the

Type

3A2

or

3876)

in

the

left

plug-in

compartment

of

the

oscilloscope

(see

Fig.

2-1).

Place

the

horizontal

plug-in

unit

(for

example,

the

Type

382

or

3177)

in

the

center

compartment.

Finally,

place

the

desired

digital

unit

(for

example,

the

Type

éRI

or

6RIA)

in

the

right

compartment

of

the

oscilloscope.

Make

certain

all

units

are

properly

inserted

and

locked

in

place

before

turning

on

the

oscilloscope

power.

The

horizontal

and

vertical.

plug-in

units

are

locked

in

place

by

turning

the

front-panel

knurled

‘aluminum

locking

knobs

clockwise.

The

digital

unit

is

locked

in

place

by

removing

the

right

side

panel

and

tightening

the

two

fasteners

at

the

rear

of

the

compartment.

Fig.

2-1,

Type

567

plug-in

co

yartments

Checking

Plug-In

Ui

Each

vertical,

horizontal

and

digital

plug-in

unit

must

be

calibrated

within

the

particular

oscilloscope

in

which

it

is

to

be

operated.

Units

purchased

as

a

system

(oscilloscope

‘and

three

plug-ins)

are

calibrated

together

as

a

system

at

the

factory,

Units

purchased

separately,

or

calibrated

separately,

must

have

their

basic

gain

adjusiments

made

when

they

are

installed

Accuracy

Individual

oscilloscope

crt

deflection

factors

differ

within

normal

limits.

The

vertical

and

horizontal

units

have

front:

panel

Calib

controls

so

the

particular

amplifier

gain

can

be

set

to

that

needed

by the

crt.

Some

sampling

plug-in

units

have

internal

digital

gain

controls

that

must

be

correctly

adjusted.

See

the

individual

plug-in

unit

instruction

manval

calibration

procedure

for

details.

The

digital

unit

is

sensitive

to

the

oscilloscope

power-supply

voltages.

Digital

readout

accuracy

is

closely

power-supply

voltage

accuracy.

Since

it is

impossible

to

21

Operating

Instructions—Type

567

make

all

Type

567

Oscilloscope

power

supplies

to

have

exactly

the

same

voltage

accuracy,

the

digital

unit

must

be

calibrated

in

the

oscilloscope

in

which

it

is

used.

If

a

cali-

brated

digital

unit

(either

Type

6R1

or

6RIA)

is

placed

into

another

Type

567

Oscilloscope,

check

the

accuracy

of

the

start

and

stop

voltages

and

the

rate

of

rise

of

the

voltmeter

ramp

before

relying

on

either

time

or

voltage

readout.

See

the

digital

unit

instruction

manual

calibration

procedure

(Type

6RIA

steps

5

and

6;

Type

6R1

steps

15

and

17}

for

details.

Intensity

Control

The

INTENSITY

control

is

used

to

adjust

the

brightness

of

the

oscilloscope

display.

Begin

with

INTENSITY

control

counterclockwise,

because

some

plug-ins

permit

a_

bright

spot

during

warm

up.

After

turning

on

the

instrument

and

waiting

a

few

minutes

for

warm

up,

free

run the

oscilloscope

sweep

by

setting

the

TRIGGER

SENSITIVITY

or

LEVEL

control

fully

clockwise.

Adjust

the

INTENSITY

control

for

a

suitable

trace

intensity.

Do

not

leave

a

bright,

sharply

focused

spot

on

the

crt

screen

for

a

prolonged

period.

An

excessively

bright

sta-

tionary

spot

may

damage

the

crt

phosphor.

Focus

and

Astigmatism

Controls

The

FOCUS

and

ASTIGMATISM

controls

are

used

in

con-

junction

with

each

other

to

produce

a

well-focused

display

on

the

oscilloscope

screen.

Because

changes

in

the

setting

of

the

INTENSITY

control

may

affect

focus

slightly,

the

trace

should

be

focused

with

the

actual

waveform

displayed

and

with

the

desired

intensity

setting.

Refer

to

the

appropriate

plug-in

manuals

for

instructions

for

applying

a

signal

to

the

oscilloscope

and

obtaining

a

stable

display.

With

a

signal

displayed,

carefully

adjust

the

FOCUS

and

ASTIGMATISM

controls

alternately

for

best

possible

focus

over

the

entire

display.

There

is

an

intensity

level

above

which

a

good

focus

is

impossible

to

attain.

Scale

Illumination

Control

The

ert

graticule

is

edge-lighted

by

two

small

lamps

at

the

bottom.

The

lighting

can

be

adjusted

to

suit

the

ambient

light

conditions

by

means

of

the

SCALE

ILLUM

control.

Rotating

the

control

clockwise

increases

the

brightness

of

the

graticule

scale

markings.

The

graticule

is

marked

with

eight

1-centimeter

divisions

vertically

and

ten

1-centimeter

divisions

horizontally,

with

2-millimeter

markings

on

the

centerlines.

Changing

Plug-In

Units

Horizontal

and

vertical

plug-in

units

used

in

the

Type

567

may

be

changed

at

any

time.

However,

it

is

recommended

that

the

instrument

be

turned

off

while

a

change

is

made.

This

affords

maximum

protection

to

the

oscilloscope

and

other

plug-in

units

against

sudden

transients

and

load

changes.

Whenever

a

horizontal

or

vertical

plug-in

unit

is

changed,

it

is

important

that

you

check

both

the

gain

and

timing

of

the

oscilloscope.

This

will

ensure

accurate

measurements.

2-2

Se

LR

Ao

Amplitude

Calibrator

(SN

2060-up)

The

Amplitude

Calibrator

provides

a

choice

of

four

square-

wave

voltages

with

amplitude

tolerance

of

+2%.

0.5

and

5

volts

peak

to

peak

when

loaded

(one

or

both

at

the

same

time)

by

100k

or

greater,

and

50

and

500

mv

when

loaded

(one

at

a

time)

by

502

+1%.

Two

frequencies

are

avail-

able:

crystal-controlled

20-kc

{=:0.1%)

square

waves,

and

1-ke

(--20%)

square

waves.

The

two

frequencies

are

select-

able

by

a

front-panel

20

KC-==1

KC

toggle

switch.

The

volt-

age

accuracy

of

any

one

of

the

four

output

voltages

may

be

adjusted

to

within

—%%

by

special

calibration.

The

Amplitude

Calibrator

is

valuable

for

adjusting

the

front-panel

Calib

controls

of

both

vertical

and horizontal

real-time

or

sampling

plug-in

units.

The

20-ke

frequency

(and

the

ability

to

make

one

of

the

output

voltages

very

accurate}

permits

checking

the

system

operation

including

digital

unit

time

and

voltage

readout.

The

1-ke

frequency

is

valuable

for

compensating

low-frequency

attenuator

probes.

Front-panel

BNC

connectors

permit

convenient

50

cable

connection

of

calibrator

signals

to

the

plug-in

unit

input

terminals,

or

to

external

equipment.

If

the

vertical

plug-in

unit

has

a

high-impedance

input,

the

two

higher

square-wave

voltages

will

apply.

Addition

of

an

external

50Q

termina-

tion

(Tektronix

Part

No.

011-0049-00)

at

the

plug-in

input

connector

will

provide

the

two

lower

voltages.

If

the

plug-in

unit

has

an

internal

50

Q

termination,

do

not

add

the

external

termination

when

accurate

voltages

are

desired.

(Actually,

the

Amplitude

Calibrator

is

short-circuit

proof,

so

any

load

is

permissible,

but

accurate

voltages

are

obtainable

only

as

above.)

The

+Pre

Trigger

connector

delivers

a

positive

pulse

ap-

proximately

4

cycle

before

each

positive

step

of

both

the

20-kc

and

1-kc

square-wave

signals.

Sampling

plug-in

time-

base

units

can

effectively

use

the

+Pre

Trigger

signal

(at

20

kc)

for

external

triggering.

A

positive

step

will

then

appear

near

the

beginning

of

the

display,

produced

without

external

delay

cable

in

the

pretrigger

signal

path.

(S/N

300-2059)

The

Amplitude

Calibrator

provides

a

choice

of

four

square-

wave

signals

with

peak-to-peak

voltages

of

0.05,

0.5,

5

and

50 volts

--3%

when

loaded

by

1

megohm

or

greater.

In

addition,

a

signal

of

100

mv

peak

to

peak

+3%

into

a

502

(1%)

resistance

is

provided

from

the

0.5

jack.

This

voltage

is

valuable

for

checking

the

vertical

calibration

of

sampling

plug-in

units.

Frequency

of

the

square

wave

is

that

of

the

power

line.

(S/N

101-299)

The

Amplitude

Calibrator

provides

a

choice

of

four

square-

wave

signals

with

peak-to-peak

voltages

of

0.05,

0.5

5

and

50 voits

+3%

when

loaded

by

1

megohm

or

greater.

Fre-

quency

of

the

square

wave

is

that

of

the

power

line.

The

Amplitude

Calibrator

is

valuable

for

checking

real-time

plug-

in

unit

calibration

and

the

compensation

of

attenuator

probes.

It

is

also

valuable

as

a

time

reference

for

adjusting

the

horizontal

unit

calibration;

three

complete

cycles

at

60

cps

line

frequency

occur’

in

50

milliseconds

(2

cycles

at

50

cps

line

frequency

occur

in

40

milliseconds).

SHORT

N

0

S

wv

o

4

€

4

=

oc

2

Kj

wu

a

Zz

wi

wu

2

wy

/

PP

/

Qax

L

“

/

wn

~

ae

s/

-

g,

-

~

<q

a

z

°r

w

£

/

of

T

TT

T

TTT

T Lo

|

t‘)

25

50

75

LOAD

CURRENT

OF

ONE

PLUG-IN

UNIT

(Milliamperes)

Fig.

2-2.

—100-volt

supply

shunt.

Skeleton

Plug-In

Units

Skeleton

plug-in

units

for

the

vertical

and

horizontal

sec-

tions

are

available

for

all

of

the

Tektronix

Type

560

Series

oscilloscopes,

including

the

Type

5467.

None

are

available

for

the

large

plug-in

area

used

for

digital

readout.

These

skele-

ton units

permit

you

to

build

your

own

plug-in

circuitry

for

use

in

the

Type

567.

If

you

use

your

own

circuitry,

pro-

vision

may

be

made

for

operating

the

digital

readout

cir-

cuits,

although

this

is

not

necessary.

Order

the

skeleton

chassis

as

Modification

Kit

number

040-0245-00

from

your

local

Tektronix

Field

Office.

A

dummy

cover

is

available

for

the

digital

cell.

Order

by

Tektronix

Part

No.

016-0051

-00.

Power

Supply

Capabilities

The

total

de

power

available

for

vertical

and

horizontal

plug-in

use

is

85

watts

divided

between

four

regulated

sup-

plies.

The

remaining

power

available

must

be

reserved

for

the

digital

units.

Use

of

current

from

any

of

the

unregulated

de

supply

leads

is

not

recommended.

The

four

regulated

de

supplies

listed

in

Table

2-1

are

em-

ployed

by

the

X

and

Y

axis

amplifiers.

Since

the

Type

567

indicator

unit

employs

two

plug-in

units

to

operate

the

X

and

Y

axes

of

the

crt,

currents

listed

in

Table

2-1

are

normally

divided

between

them.

However,

a

single

plug-in

alone

can

be

used,

such

as

a

vertical

ampli-

fier,

with

moving-film

recording

used

instead

of

a

horizontal

sweep.

In

such

a

case,

it

will

be

necessary

to

elevate

the

crt

horizontal

deflection

plates

to

approximately

+180

to

On

Operating

Instructions—Type

567

TABLE

2-1

Type

567

Power

Supply

Current

Capabilities

For

X

and

Y

Plug-In

Units

Supply

Max.

Total

Connector

Current

Terminals

Reg.

—100

vdc

130

ma

23—

to

9

ground

Reg.

—12.2

vdc

1.5

amps

16—

to

5

ground

~

Reg.

+125

vde

_

150

ma

15+

to

9

ground

Reg

+300

vde

150

ma

10+

to

9

ground

5

amps

per

Unreg.

6.3

vac

plug-in

1-2

+210

volts

de

to

permit

proper

focus

and

astigmatism

control.

The

limit

of

the

amount

of

power

which

can

be

dissipated

in

one

plug-in

unit

is

based

primarily

upon

the

ambient

temperature

and

amount

of

ventilation

supplied.

Vacuum

tubes

should

not

be

operated

with

envelope

temperatures

above

150°

C

when

the

ambient temperature

is

at

25°

C,

or

above

175°

C

when

the

ambient

temperature

is

at

50°

C.

The

Type

567

indicator

unit

can

be

operated

in

ambient

temperatures

up

to

45°C.

Separate

terminals

are

provided

for

the

ground

return

of

the

—12.2-volt

regulated

heater

supply.

When

using

this

supply

in

your

own

plug-in

design,

it

is

best

to

run

two

leads

to

the

heater

terminals

so

that

the

ground

lead

can

be

connected

directly

to

terminal

5,

thus

eliminating

ground

currents.

SHO

°

N

of

~

BS)

~

S

Zz

¥

=2«

v4

=

i!

z

/

|

br

x/

|

=

ey

|

a

o/

|

oc

Oak

f

a

/

a

y

|

wi

4

ac

|

-

/

,

|

<

/

=

J

|

of

|

qT

T

qT

Li

LU

T L

qv

Lu

qT

0

25

50

75

LOAD

CURRENT

OF

ONE

PLUG-IN

UNIT

(Milliamperes)

Fig.

2-3.

+

125-volt

supply

shunt.

2-3

Operating

Instructions—Type

567

SHORT

2°

of

-)

Ry

S

2

€

z

=

2

w

z

Ww

= A

a

/

|

Pi

7

Oak

¥

4

:

wn

a

7

|

K

7

5

oy

|

>|

7

|

w

a

of

T

J

q L

1

v

1

T

J

T

25

50

75

LOAD

CURRENT

OF

ONE

PLUG-IN

UNIT

(Milliamperes)

Fig.

2-4.

+300-volt

supply

shunt.

above

150°

C

when

the

ambient

temperature

is

at

25°

C,

or

above

175°

C

when

the

ambient

temperature

is

at

50°

C.

The

Type

567

indicator

unit

can

be

operated

in

ambient

temperatures

up

to

45°C.

Separate

terminals

are

provided

for

the

ground

return

of

the

—12.2-volt

regulated

heater

supply.

When

using

this

supply

in

your

own

plug-in

design,

it

is

best

to

run

two

leads

to

the

heater

terminals

so

that

the

ground

lead can

be

connected

directly

to

terminal

5,

thus

eliminating

ground

currents.

TABLE

2-2

Recommended

Type

567

Regulated

Power-Supply

Shunt

Resistors?

Shunt

Resistor

Values

—100v

+125

v

+300

v

No

Shunt

|

0

to

25ma|

0

to

45ma|

0

to

40ma.

20009,

5w_

be-

tween

proper

ter

|

99

+9

45ma|25

to

60ma

35

to

67ma

minals

of

power

connector.

_

SHORT,

between

proper

terminals

of

pow-

|

40

to

65ma/50

to

75

ma

|65

to

75

ma

er

connector.

1Currents

listed

are

one-half

total

available,

based

on

two

plug-

in

units

being

used.

Suggested

Power-Supply

Shunt

Resistor

Values

To

make

efficient

special

use

of

the

Type

567

indicator

unit

power

supply,

the

load

currents

and

maximum

or

mini-

mum

load

values

must

be

known.

2-4

os

wie

|

TL

pote

Lx

94

*ce7es

T

{

+

+t

Yaa

ty

ry

rr

|

anne

(ie

>

wet

|

ima

+

;

oY

Y

"

seeped

j

a

i!

|

| | |

pei

i

|

na

Lp

tl

|

Pel

y

aon

Hel

|

l

Bonne

ws

bly bls

B6tes

MIL

dt

ly

|

ly

tel

1

td

wane

Cese

oo

33

tisst,

_—e

re

Po.

ay

ete

p

woe

V6274

a

|

Uh

ed

2

©

|

4{=>

46080

T

ho

I

i

24

ee

©

|

"2043

youre

meas

1

oe|

|

r4

Molen

[chee

aah

mn

deere

|

rh)

ADE

pegee

gnsze

7

ASor

| |

Gia

|

| I | |

t

FL

to6!

in

ee

iy

Le

Ju

2b

gt

Terminals

X,

Y¥,

and

Z

are

located

in

plug-in

units

X

=

+300-Volt

Shunt

Y

=

+125-Volt

Shunt

Z

=

—100-Volt

Shunt

Fig.

2-5.

Power-supply

shunt

resistor

connections.

The

nature

of

series-regulated

power

supplies

permits

ob-

taining

more

current

from

them

than

can

normally

be

handled

by

the

series

tube

alone

(providing

the

power

transformer

and

rectifiers

can

supply

more

current).

By

placing

a

shunt

resistor

of

appropriate

value

across

the

series

regulator

tube,

additional

current

can

be

made

available

for

the

load.

The

correct

value

shunt

resistor

must

be

chosen

to

permit

the

regulator

system

to

deliver

current

with

low

ripple,

and

the

Use

of

shunt-resistor

values

suggested

in

Table

2-2

will

lead

to

a

minimum

of

total

power

required,

and

give

lowest

plug-in

temperature.

It

is

the

simplest

method

that

will

not

overtax

supplies,

either

for

regulation

or

temperature.

How-

ever,

if

Table

2-2

does

not

meet

your

design

needs,

refer

to

the

curves

of

Figs. 2-2, 2-3,

or

2-4

to

aid

your

choice

of

individual

power-supply

shunt

resistors.

Always

plan

the

shunt

to

permit

lowest

plate

dissipation

in

the

series

regulator

tube

consistent

with

proper

regulation

and

ripple

values.

A

portion

of

the

power-supply

schematic

has

been

re-

produced

in

Fig.

2-5,

identifying

interconnecting

plug

termi-

nals

specified

in

Table

2-3.

J11

and

J21

are

the

horizontally-

mounted

interconnecting

plugs

at

the

rear

of

the

vertical

and

®)1

Operating

Instructions—Type

567

horizontal

plug-in

cells,

respectively.

Do

not

use

shunt

re-

sistors

in

the

digital

cell

at

J31.

TABLE

2-3

Plug-In

Interconnecting

Plug

Terminals

For

Regulated

Supply

Shunt

Resistors

In

X

and

Y

Amplifiers

Supply

Terminals

—100

22—9

return

+125

20—15

return

+300

6—10

return

NOTES

SECTION

3

CIRCUIT

DESCRIPTION

General

Information

The

Type

567

Oscilloscope

consists

of

three

major

parts:

the

low-voltage

power

supplies,

the

crt

circuits,

and

the

Amplitude

Calibrator.

The

oscilloscope

is

essentially

an

indi-

cater

and

power

supply

for

the

plug-in

units

used

with

the

instrument.

Vertical

and

horizontal

plug-in

units

drive

the

deflection

plates

of

the

crt

directly,

and

also

drive

the

digital

unit.

The

low-voltage

power

supplies

provide

outputs

of

—100,

—12.2,

+20,

+125,

and

+300

volts.

The

crt

circuits

contain

the

high-voltage

power

supply

and

crt.

The

high-voltage

supply

provides

regulated

3.3-kv

poten-

tial

to

the

crt

cathode.

The

Amplitude

Calibrator

generates

square

waves

with

calibrated

amplitudes

at

either

20

kc

or

1

ke.

The

calibrator

square

waves

are

used

as

a

convenient

signal

source

to

verify

the

calibration

of

the

vertical,

horizontal,

and

digital

plug-in

units.

Low-Voltage

Power

Supplies

Low-voltage

power

supplies

of

the

Type

567

supply

all

the

power

to

the

high-voltage

power

supply,

the

Amplitude

Calibrator,

and

the

three

plug-in

units.

Each

regulated

output

voltage

is

stable

over

the

line

voltage

range

of

105

to

125

volts

rms,

or

210

to

250

volts

rms,

centered

at

either

117

or

234

volts

50

to

60

cps.

The

supplies

will

remain

within

regulation

for

line-voltage

distortion

up

to

about

5%.

All

regulated

power

supplies

are

referenced

to

V609

of

the

—100-volt

supply;

the

output

voltage

of

the

—100-volt

supply

is

the

reference

voltage

for

all

other

regulated

supplies.

Vertical

and

horizontal

plug-in

units

use

power

from

all

but

the

+20-volt

supply.

The

+20-volt

supply

is

used

by

the

digital

unit

and

can

be

used

externally

through

the

digital

unit

(Type

6R1

or

6RIA

J34-G)

at

currents

up

to

500

ma.

Three

of

the

power

supplies

include

shunt

resistors

that

allow

more

current

to

be

drawn

than

can

be

handled

by

the

series

regulators

alone.

A

discussion

of

power-supply

loads

and

shunts

is

included

in

the

section

on

Operating

Instructions.

—100-Volt

Power

Supply

Line

voltage

is

applied

through

fuse

F601

and

the

ther-

mal

cutout

relay

TK601

to

the

primary

windings

of

T601.

This

energizes

the

secondary

windings

of

T601.

Terminals

19

and

20

of

T601

apply

power

to

a

full-wave

bridge

rectifier

consisting

of

D602A,

B,

C,

and

D.

The

unregulated

output

of

the

rectifier

circuit

is

applied

to

the

—100-volt

regulator

cir-

cuit

and

through

the

interconnecting

plugs

to

the

plug-in

units.

Voltage

regulator

tube

V609

maintains

the

grid

of

V616B

at

approximately

—85

volts.

The

voltage

at

the

grid

of

V616A

is

obtained

from

a

divider

between

ground

and

the

—100-volt

output

of

the

regulator.

V616

is

a

cathode-coupled

difference

amplifier

which

compares

the

voltage

at

the

grid

of

V616A

against

the

fixed

—85

volts

at

the

grid

of

V616B.

Potentiometer

R624

sets

the

output

of

the

power

supply

at

—100

volts.

If

the

output

voltage

tends

to

change

from

—100

volts,

a

sample

of

the

change

is

applied

through

the

divider

to

the

grid

of

V616A.

This

error

signal

is

amplified

and

inverted

by

V616A

and

applied

to

the

base

of

Q624.

Q624

amplifies

and

inverts

the

error

signal

and

applies

it

to

the

grid

of

series

regulator

V627A.

The

change

in

grid

voltage

of

V627A

changes

the

voltage

drop

across

the

tube

and

causes

the

output

voltage

to

return

to

normal.

Capacitor

C625

increases

the

ac

loop

gain

of

the

regulator

circuit.

Its

function

is

to

quickly

compensate

for

rapid

changes

in

the

output

voltage.

The

higher

ac

loop

gain

provided

by

C625

also

reduces

ripple

at

the

output

of

the

regulator.

C626

aids

in

reducing

the

ac

output

impedance

of

the

—100-

volt

supply.

+125-Volt

Power

Supply

A

full-wave

bridge

rectifier

circuit

from

terminals

33

and

34

of

T601

supplies

power

to

the

+125-volt

regulator

cir-

cuit

and

to

the

plug-in

units

through

the

interconnecting

plugs.

The

+125-volt

supply

compares

its

own

output

volt-

age

with

the

—100-volt

supply

through

the

resistive

voltage

divider

R674-R675.

The

divider

supplies

a

voltage

near

ground

to

the

grid

of

V664.

If

the

output

voltage

from

the

regulator

changes,

a

portion

of

this

change

is

applied

through

the

divider

to

the

grid

of

error

amplifier

V664.

The

error

signal

is

amplified

by

V664

and

applied

to

the

grids

of

series

regulator

V677.

The

change

in

voltage

at

the

grids

of

V677

changes

the

voltage

drop

across

V677

and

compen-

sates

for

the

change

in

output

voltage.

The

screen

supply

for

V664

is

obtained

primarily

from

the

output

of

the

regulator

circuit.

R665

applies

ripple

from

the

unregulated

bus

to

the

screen

as

a

signal

voltage.

The

ripple

is

amplified

and

helps

to

reduce

ripple

appearing

on

the

output.

Capacitor

C674

is

used

to

increase

the

ac

loop

gain

of

the

regulator

circuit.

This

allows

the

circuit

to

recover

rapidly

from

sudden

changes

in

output

voltage.

The

increased

ac

loop

gain

also

helps

to

reduce

the

ripple

at

the

output

of

the

regulator.

C676A

reduces

the

ac

impedance

of

the

+125-volt

supply.

Resistors

R671

and

R676

in

the

cathodes

of

the

series

regulator

V677

tend

to

balance

the

current

through

the

two

sections

of

the

tube.

On

all

Type

567s

S/N

300-up,

the

+125-volt

supply

is

adjustable

by

R667

and

R668,

The

—100-volt

supply

must

be

adjusted

to

the

correct

voltage

before

adjusting

R668

to

set

the

+125-volt

supply

to

the

correct

value.

3-1

Circuit

Description—Type

567

+300-Volt

Power

Supply

A

full-wave

bridge

rectifier

circuit

from

terminals

31

and

32

of

T1601

supplies

+165

unregulated

dc

volts

that

are

added

to

the

unregulated

+235

volts

(of

the

+125-volt

regu-

lated

supply)

to

provide

a

total

of

+400

volts

to

the

+300-

volt

regulator

and

to

the

ert

circuit. A

voltage

divider

between

the

regulator

output

and

—100

volts,

supplies

a

voltage

near

ground

to

the

grid

of

V684.

If

the

output

voltage

from

the

regulator

changes,

a

portion

of

this

change

is

applied

through

the

divider

and

C694

to

the

grid

of

error

amplifier

V684.

The

error

signal

is

amplified

and

inverted

and

applied

to

the

grid

of

series

regulator

V627B.

The

change

in

voltage

at

V627B

grid

changes

V627B

conduction

and

compensates

for

the

change

in

output

voltage.

The

screen

supply

for

V684

is

obtained

from

both

the

+400-volt

unregulated

lead

and

from

the

regulated

+300

volts.

R685

applies

ripple

voltage

from

the

unregulated

lead

as

a

signal

to

V684

screen

to

help

reduce

ripple

volt-

age

appearing

in

the

regulated

output.

Capacitor

C694

supplies

fast

changes

in

output

voltage

to

the

grid

of

error

amplifier

V684,

reducing

the

ac

output

impedance

of

the

regulator

circuit.

C676B

also

aids

to

reduce

the

ac

impedance

of

the

+300-volt

supply.

On

all

Type

567s

S/N

300-up,

the

+300-volt

power

supply

is

adjustable

by

R696

and

R698.

Both

the

—100-

and

+125-

volt

power

supplies

must

be

adjusted

before

calibrating

R698,

—12.2-Volt

Power

Supply

The

—12.2-volt

regulator

is

similar

to

the

—100-volt

regulator

except

that

it

uses

transistors

instead

of

tubes.

A

full-wave

rectifier

consisting

of

D632A

and

B

provides

unregulated

de

voltage

to

the

regulator.

A

divider

be-

tween

—100

volts

and

ground

is

used

to

provide

a

constant

—12

volts

for

the

base

of

Q634.

The

output

voltage

of

the

regulator,

appearing

at

the

emitter

of

Q634,

is

compared

to

the

voltage

at

the

base.

Because

of this

circuit

arrange-

ment,

the

voltage

at

the

base

of

@634

sets

the

output

volt-

age

of

the

supply.

Normally,

the

voltage

at

the

emitter

and

base

of

Q634

will

be

nearly

the

same.

If

the

voltage

at

the

emitter

changes

because

of

a

change

in

the

supply

output

voltage,

this

changes

the

current

through

the

transistor.

This

in

turn

produces

a

change

in

the

collector

voltage

of

@634

and

in

the

base

voltage

of

Q644.

The

change

at

the

base

of

Q644

is

amplified

at

the

collector

and

applied

to

the

base

of

the

series

regulator

transistor

Q647.

The

change

in

base

voltage

of

Q647

changes

the

voltage

drop

across

Q647

in

such

a

direction

as

to

compensate

for

the

change

in

output

voltage,

and

the

output

then

returns

to

normal.

As an

example,

if

the

output

of

the

supply

starts

to

go

more

negative,

this

causes

Q634

to

conduct

more

heavily.

This

produces

a

drop

in

the

voltage

at

the

collector

of

Q634

and

at

the

base

of

@644.

The

drop

in

voltage

at

the

base

of

Q644

also

causes

this

transistor

to

conduct

more

heavily,

causing

its

collector

voltage

to

change

in

the

positive

direc-

tion,

The

more

positive

voltage

at

the

base

of

Q647

in-

creases

the

voltage

drop

across

Q647,

thereby

decreasing

the

output

voltage

of

the

supply

to

normal.

3-2

Fuse

F647

is

used

to

protect

Q647

in

the

event

the

output

is

accidentally

overloaded.

Capacitor

C646

reduces

ripple

voltage

at

the

output

of

the

regulator

circuit.

On

all

Type

567s

S/N

300-up,

the

—12.2-volt

supply

is

adjustable

by

R630,

R631,

and

R632. Both

the

—100-

and

+125-volt

power

supplies

must

be

adjusted

before

calibrat-

ing

R631.

+20-Volt

Power

Supply

Full-wave

bridge

rectifier

D652A,

B,

C,

and

D

rectifies

voltage

from

terminals

11

and

12

of

1601

and

_

supplies

power

to

the

+20-volt

regulator

circuit.

A

voltage

divider

between

+125

volts

and

ground

sets

the

base

of

Q654

near

+20

volts.

The

output

voltage

of

the

supply,

appearing

at

the

emitter

of

Q654,

is

compared

to

the

voltage

at

the

base.

If

the

supply

voltage

changes,

the

bias

and

conduction

of

Q654

is

changed.

Supply

voltage

changes

are

then

ampli-

fied

and

inverted

and

applied

to

the

base

of

emitter-follower

@653.

@Q653

provides

current

gain

to

the

correcting

signal

and

drives

the

base

of

Q657

to

change

its

conduction

and

bring

the

output

voltage

back

to

normal.

C654

provides

a

low

ac

impedance

to

Qé654

base,

reducing

the

supply

ac

output

impedance.

C656

and

C657

also

aid

to

reduce

the

supply

ac

output

impedance.

Fuse

F657

protects

Q657

in

the

event

the

output

is

ac-

cidentally

overloaded.

On

all

Type

567s

S/N

300-up,

the

+20-valt

supply

is

adjustable

by

R650

and

R651.

R650

is

connected

between

the

—12.2-

and

the

output

of

the

+20-volt

supply.

Thus,

the

—12,2-

and

+125-volt

power

supplies

must

both

be

adjusted

to

the

correct

voltage

before

adjusting

R650

to

set

the

+20-

volt

supply

to

the

correct

value.

High-Voltage

Power

Supply

Unregulated

+400

volts

from

the

+300-volt

power

sup-

ply

is

applied

to

the

high-voltage

oscillator,

V800.

V800

and

its

associated

circuitry

is

a

modified

Hartley

oscillator.

C802

and

the

primary

winding

of

T801

form

the

tuned

circuit

in

the

plate

of

V800.

The

oscillator

operates

at

approximately

35

kc.

High-voltage

transformer

T801

provides

the

high

volt-

ages

and

heater

voltages

for

the

rectifiers.

One

secondary

winding

of

T801

and

rectifier

V822

form

a

half-wave

rectifier

circuit

which

supplies

approximately

—3.3

kv

to

the

cathode

of

the

crt.

A

separate

secondary

winding

of

T801

and

V832

supply

a

floating

negative

voltage

for

the

control

grid

of

the

crt.

A

voltage

divider

between

the

—3.3-kv

output

of

V822

and

+300

volts

supplies

voltage

to

the

focusing

grid

of

the

crt

and

also

applies

a

sample

of

the

power-supply

output

to

the

high-voltage

regulator

circuit,

Potentiometer

R841

sets

the

high

voltage.

If

the

output

voltage

changes

from

this

set

value,

a

portion

of

the

change

appears

at

the

grid

of

V814B

as

an

error

signal.

The

error

signal

is

amplified

by

V814B

and

V814A

and

applied

to

the

screen

grid

of

the

High

Voltage

Oscillator

V800.

The

change

in

screen

voltage

on

the

oscillator

causes

either

an

increase

or

a

decrease

in

the

amplitude

of

the

oscillations.

The

change

in

amplitude

of

the

oscillations

is

always

in

a

direction

to

compensate

for

the

error

in

the

output

voltage.

The

output

voltage

from

V832

is

not

regulated

directly,

but

is

regulated

indirectly

by

the

operation

of

the

V800

screen

grid

regulator

loop.

Capacitor

C842

greatly

increases

the

ac

loop gain

of

the

high-voltage

regulator

circuit,

This

permits

the

regulator

to

quickly

compensate

for

rapid

changes

in

the

output

voltage.

Crt

Circuits

Voltage

for

the

control

grid

of

the

crt

is

obtained

from

R834 and

R833

at

the

output

of

the

control

grid

power

supply.

By

varying

the

setting

of

the

INTENSITY

control

R834,

the

voltage

at

the

control

grid

relative

to

the

cathode

can

be

changed

to

provide

the

desired

display

brightness.

Begin-

ning

with

S/N

249,

neon

glow

tubes

B852-B853

were

added.

The

bulbs

ignite

only

when

the

INTENSITY

control

is

fully

counterclockwise.

Thus,

both

the

grid

and

cathode

of

the

crt

are

protected

from

arcing.

Voltage

for

the

focus

grid

of

the

crt

is

obtained

from

potentiometer

R845.

The

Astigmatism

element

receives

its

voltage

from

potentiometer

R864.

Varying

both

R845

and

R864

affects

the

crt

spot

size.

The

presence

and

intensity

of

the

crt

beam

is

controlled

by

signals

from

each

of

the

three

plug-in

units

used

with

the

Type

567.

The

oscilloscope

uses

deflection

unblanking

during

the

sweep

interval.

In

this

method

an

additional

pair

of

deflection

plates

in

the

crt

electron

gun

deflects

the

beam

off

the

screen

except

during

the

sweep.

When

the

horizontal

sweep

is

triggered,

the

unblanking

signal

is

applied

from

the

time-base

unit

through

terminal

13

of

J21

to

one

of

the

unblanking

deflection

plates.

The

unblanking

signal

then

moves

the

electron

beam

rapidly

on

screen

for

the

duration

of

the

sweep.

The

beam

is

then

deflected

off

screen

again

until

time

for

the

Chopped

mode

blanking

signals

from

a

multi-trace

vertical

plug-in

unit

are

applied through

terminal

24

of

J11

to

the

cathode

of

the

crt.

These

blanking

signals

are

used

to

blank

switching

transients

which

result

when

the

plug-in

unit

is

operated

in

the

chopped

mode.

Chopped

blanking

prevents

the

chopping

transients

from

being

displayed

on

the

crt

at

normal

intensity.

Intensity

brightening

of

the

crt

trace

by

either

the

digital

unit

or

a

two-sweep

time-base

unit

is

accomplished

by

cou-

pling

brightening

signals

to

the

reference

voltage

for

the

crt

grid-voltage

supply.

The

brightening

signal

from

the

digital

unit

changes

the

overall

grid

supply

voltage

through

terminal

15

of

J32.

The

brightening

signal

from

the

two-sweep

tim-

ing

unit

changes

the

overall

grid

supply

voltage

through

terminal

14

of

J21.

Two

diodes,

D836

and

D837,

provide

a

low-impedance

return

for

the

crt

grid

circuit,

reducing

intensity

modulation

caused

by

any

normal

power-supply

ripple.

Diode

D835

disconnects

+125

volts

applied

to

terminal

14

of

J21

by

some

plug-in

units.

Sharply

differentiated

blanking

pulses

from

the

vertical

sampling

unit

are

applied

to

the

crt

cathode

through

ter-

minal

24

of

J11

to

turn

off

the

crt

beam

between

sampling

dots.

Thus,

the

crt

beam

is

blanked

between

dots,

avoiding

possible

display

confusion.

A

beam

rotator

coil

around

the

crt

is

used

to

align

the

oscilloscope

trace

with

the

horizontal

graticule

markings.

Circuit

Description—Type

567

The

magnetic

field

set

up

by

the

coil

deflects

the

electron

beam

up

on

one

side

of

the

crt

and

down

on

the

other.

8y

varying

the

strength

and

direction

of

the

field

with

the

CRT

BEAM

ROTATOR

control,

the

trace

can

be

aligned

with

the

graticule

markings.

Amplitude

Calibrator

(S/N

2060-up)

The

Amplitude

Calibrator

is

a

two-frequency

signal

source

that

is

crystal

controlled

at

20kc

and

rc_time-constant

controlled

at

approximately

1kc.

An

astable

multivibrator

drives

both

a

divide-by-two

bistable

multivibrator

and

a

positive

slope

differentiator

circuit.

Square

waves

of

known

amplitude

at

the

front-panel

connectors

come

from

the

+2

circuit,

and

positive

pretrigger

pulses

come

from

the

dif-

ferentiator

circuit.

The

+2

circuit

clamps

off

the

differen-

tiator

every

other

astable

cycle.

Thus,

the

positive

pretrigger

pulse

is

generated

approximately

Y%,

cycle

before each

positive

portion

of

the

output

square

wave.

Selection

of

output

frequency

is

by

a

front-panel

20

KC-

=1KC

toggle

switch.

The

switch

is

open

for

20-kc

opera-

tion,

but

is

closed

for

1-kc

operation.

20-kc

operation

places

a

series-mode

40-kc

crystal

in

the

feedback

path.

1-kc

opera-

tion

places

a

0.0033

uf

capacitor

across

the

crystal,

making

feedback

capacitive

and

the

frequency

rc

controlled.

Astable

Oscillator.

Q900

and

Q914

form

a

common-

emitter

astable

multivibrator.

The

regenerative

feedback

circuit

consists

of

the

common

connection

of

the

two

transistor

emitters,

and

the

crystal

(Y905)

from

Q900

collector

to

Q914

base

for

20-kc

operation,

or

€904-D904

in

parallel

with

the

crystal

for

1-kc

operation.

D904

is

reverse

biased

(for

20-

kc

operation}

by

the

voltage

divider

R912-R914;

thus

C904

is

effectively

switched

out

of

the

circuit.

D904

is

forward

biased

when

SW915

connects

R915

in

parallel

with

R912,

con-

necting

C904

tn

parallel

with

Y905.

Both

circuit

conditions

are

shown

in

simplified

form

in

Fig.

3-1.

Fig.

3-la

shows

the

active

circuit

elements

for

20-kc

operation.

Note

the

parallel

resistance

value

with

equiva-

lent

voltage

source

for

R908

and

R909.

The

+21

volts

is

the

value

of

divider

voltage

when

no

current

is

drawn

through

either

R905

or

R906.

If

either

base

draws

current

through

its

20-k

resistor,

the

+21

volts

acts

as

if

it

has

a

16.6-k

source

resistance.

Fig.

3-1b

shows

the

active

circuit

elements

for

1-kc

operation.

D904

is

a

low

resistance

when

it

is

forward

biased

placing

C904

in

parallel

with

Y905.

Fig.

3-2

shows

four

astable

circuit

waveforms

during

1-kc

operation.

D904

and

C904

are

drawn

between

wave-

forms

for

study

purposes.

Note

that

D904

is

forward

biased

when

@900

collector

is

positive,

but

reverse

biased

when

@900

collector

is

near

ground;

C904

receives

a

charge

while

Q900

collector

is

positive,

but

loses

its

charge

when

Q900

collector

is

near

ground.

A

2-kc

operation

cycle

is

as

follows:

Assume

Q900

col-

lector

has

just

gone

positive.

D904

connects

C904

from

Q900

collector

to

Q914

base.

Q914

base

is

taken

about

12.6

volts

more

positive

(due

to

18-volt

charge)

cutting

Q914

off.

Q900

collector

low

resistance

connects

C904

between

+15

volts

and

+32.6

volts

at

the

junction

of

Q914

base

and

R905.

Q914

base

draws

no

current,

so

C904

begins

to

discharge

through

R905

and

Q900

collector.

Point

#1

of

Fig.

3-2

has

just

been

reached.

As

Q914

base

wave-

3-3

Circuit

Description—Type

567

+125

27

k

2R90I

+21¥

Q900

Qo14

3.8

ma

Y905

!

A\

40

ke

]

To

+

2

R904 ROI7

5.1

k

91k

=

18

¥

—

+18

~

—10¥

—+19¥

+21

v

=>

—Ov

+0.8y—

(a}

20

KC

CIRCUIT

+125

27k<R901

-O0Ov

+0.3v—

(b)

TKC

CIRCUIT

Fig.

3-1.

Simplified

Amplitude

Calibrator

astable

circuits.

form

drops

toward

+21

volts,

Q900

collector

voltage

is

pre-

vented

from

quite

reaching

+15.2

volts.

The

fast

drop

of

Q914

base

waveform

and

slow

rise

of

Q900

collector

wave-

form

are

due

to

C904

discharge.

As

the

base

of

Q914

reaches

+22.5

volts

(point

#2

of

Fig.

3-2}

Q914

begins

to

conduct,

adding

to

the

current

of

common

emitter

re-

sistor

R901.

Regenerative

action

follows

immediately

as

Q914

emitter

carries

Q900

emitter

toward

reverse

bias.

Q900

col-

3-4

lector

falls

as

its

emitter

is

taken

negative,

disconnecting

D904

from

C904.

C904

is

now

connected

at

one end

to

about

+1.42

volts

through

the

equivalent

resistance

of

17.2k

(parallel

resistance

value

of

R912

and

R915},

and

to

the

base

of

Q914

at

the

other

end.

The

charge

on

C904

limits

its

fall

at

D904

cathode

to

about

+8

volts

because

Q914

base

begins

to

draw

current

when

the

base

reaches

+15

volts.

The

parallel

resistance

of

R912-R915

and

the

base

current

of

Q914

recharge

C904.

As

the

current

through

R912-R915

decreases

(nearing

point

#3

of

Fig.

3-2)

the

cur-

rent

through

Q914

decreases

letting the

common

emitter

voltage

go

positive,

causing

Q900

to

again

conduct.

Q900

conduction

begins

and

its

collector

rises

about

2.5

volts

before

D904

again

connects

the

regenerative

feedback

circuit

so

the

astable

will

flip.

As

D904

conducts,

fast

regenerative

action

turns

Q914

off

and

Q900

on.

The

cycle

is

complete

and

C904

begins

to

discharge

to

repeat

the

process.

D904

—

oe

+14.6¥

Cathode

+8

+2¥

0904

cao4

—

——

32.6

ao14

+82.0¥

Base

+22.5v

+20v

+15v

—S————=—

a

—

+15.2¥

Q900

Collector

—>

+2.5¥

Ov

TN

_

+21¥

Qgo1l4

Collector

s

+0.3¥

4 A

&

#1

#2

#3

Fig.

3-2.

Astable

multivibrator

waveforms

during

1-kc

operation.

A

40-kc

operation

cycle

follows

the

same

sequence

of

events,

except

that

Y905

is

the

feedback

element

between

Q900

collector

and

Q914

base

and

D904

is

reverse

biased

all

the

time.

Y905

is

an

open

circuit

at

all

frequencies

other

than

its

series

resonant

frequency

of

40

kc.

The

waveform

at

the

base

of

Q914

in

Fig.

3-la

shows

the

crystal

sine

wave

nature

when

Q914

is

cut

off.

Base

current

of

Q914

flattens

off

the

waveform

bottom

as

Y905

provides

turn-on

base

cur-

rent

during

the

time

Q914

conducts.

Once

40-kc

oscillation

is

established,

the

crystal

assumes

a

mechanical

vibration

at

the

rate

of

oscillation.

At

the

time

the

operator

switches

from

20-kc

to

1-kc

operation

the

crystal

mechanical

vibration

is

seen

to

die

out

during

the

first

few

Q900

Collector

Q914

Base

Q914

Collector

Q955

Base

Q935

Base

D933

Cathode

Q925

Collector

Q935

Collector

Q955

Emitter

+

Pretrigger

D945

Cathode

Fig.

3-3.

Amplitude

Calibrator

time

diagram.

Operation

at

20

ke

(partial

graticule

shown).

moments

of

|-kc

operation.

Actually,

the

crystal

aids

in

coupling

energy

when

the

astable

is

operating

at

2kc

because

the

rapid

voltage

changes

at

each

switching

time

contain

high

frequencies.

The

crystal

then

“locks

in’

the

2-kc

oscillations

causing

the

1-kc

output

signal

to

be

very

stable.

The

actual

frequency

of

1-kc

output

cannot

be

speci-

fied

tightly

because

the

crystal’s

ability

to

lock-in

2-kc

oscillations

is

dependent

upon

transistor

beta

and

other

variables.

+2

Multivibrator.

@925

and

Q935

form

a

triggerable

bistable

multivibrator

that

divides

the

astable

output

fre-

quency

by

two.

It

drives

the

output

voltage

divider

and

controls

the

+Pre

Trigger

emitter-follower

Q955.

The

time

relationships

of

several

points

throughout

the

whole

Ampli-

tude

Calibrator

are

shown

in

Figs.

3-3

and

3-4.

Each

figure

is

made

up

of

three

multiple-exposure

photographs

made

by

externally

triggering

the

test

oscilloscope

to

guarantee

time

coincidence

of

each

waveform;

voltage

amplitudes

are

uncalibrated.

Assume

@Q925

is

conducting

and

is

saturated

so

its

cal-

lector

voltage

is

less

than

a

volt

positive.

Voltage

divider

Circuit

Description—Type

567

R925-R937

from

@925

collector

to

Q935

base

sets

Q935

base

at

about

—1.5

volts,

assuring

that

Q935

is

completely

cut

off.

D935

in

Q935

collector

circuit

permits

the

output

voltage

divider

to

disconnect

from

R934-R935.

D935

anode

voltage

is

about

+5.5

volts

and

its

cathode

and

Q935

collector

are

at

about

+20.2

volts.

Q935

collector

voltage

is

set

by

the

output

voltage

divider.

Thus,

D935

assures

that

the

output

voltage

divider

will

not

be

loaded

by

the

-+2

circuit

during

the

positive

portion

of

the

output

signal.

The

output

voltage

is

adjusted

by

R943,

and

is

completely

independent

of

the

+2

circuit.

Q925

conduction

draws

current

through

both

its

normal

collector

load

R924,

and

through

R952-D953-D954-R954_

to

bias

D951

and

Q955

to

cutoff.

When

D951

is

cut

off,

Q955

cannot

receive

positive

pulses

from

the

astable

circuit.

The

+2

multivibrator

switches

states

whenever

the

astable

output

goes

negative.

R922

holds

D923

cathode

slightly

negative

in

respect

to

its

anode,

but

not

conducting.

As

the

astable output

goes

negative,

C923

couples

a

turn-off

pulse

through

D923

to

the

base

of

Q925.

(D933

was

held

about

7

volts

reverse

biased

with

Q935

cut

off.)

As

Q925

starts

Q900

Collector

Qo14

Base

Q914

Collector

Q955

Base

Q935

Base

D933

Cathode

Q925

Collector

Q935

Collector

Q955

Emitter

+

Pretrigger

D945

Cathode

Fig.

3-4.

Amplitude

Calibrator

time

diagram.

Operation

at

1

kc

(partial

graticule

shown).

3-5

Circuit

Description—Type

567

to

turn

off,

its

collector

voltage

rises

positive,

C925

applies

turn-on

bias

to

Q935

base

and

the

+2

circuit

switches.

Regenerative

feedback

is

applied

to

Q925

base

by

Q935

collector

and

C935.

Q935

collector

now

rests

at

less

than

+0.2

volt,

close

enough

to

ground

that

D945

of

the

output

divider

carries

no

current.

Q935

collector

current

passes

through

both

its

normal

collector

load

R934

and

the

series

resistance

of

R940-R941-R943.

Q925

is

cut

off

and

its

collector

rests

at

+5

volts.

The

+2

circuit

will

change

states

the

astable

output

goes

negative

and

the

cycle

will

repeat.

+Pre

Trigger

circuit.

The

+Pre

Trigger

circuit

is

an

emitter-follower

and

differentiator

circuit

that

responses

to

positive

signals

from

the

astable

circuit

if

Q925

is

cut

off.

When

Q925

is

conducting,

D951

anode

is

held

at

about

+1.5

volts

preventing

any

positive

signal

from

being

applied

to

the

base

of

Q955.

Thus

it

is

that

a

+Pre

Trigger

pulse

is

formed

only

when

the

output

signal

is

at

ground

and

Q925

is

cut

off.

D954

allows

Q925

collector

to

rise

for

rapid

switching

of

the

+2

circuit,

C954

serves

as

a

low

impedance

so

any

stored

charge

in

D954

will

not

be

applied

to

Q955

base.

C954

also

releases

Q955

base

slowly

as

R954

charges

C954

so

Q925

positive

change

does

not

reach

Q955

base

as

a

signal.

D953

disconnects

C954

from

Q955

base

so

signals

can

couple

through

D951

and

turn

on

the

emitter-follower.

Q955

emitter

faithfully

follows

every

other

positive

astable

output

pulse.

C957

differentiates

Q955

emitter

signal

and

D959

couples

only

the

positive

pulse

to

the

output.

Any

negative

change

at

Q955

emitter,

from

either

the

astable

signal

drop

or

from

Q925

collector

pulling

down,

is

stopped

from

reaching

the

output

by

D959.

Amplitude

Calibrator

(S/N

101-299)

The

calibrator

consists

of

a

bistable

multivibrator,

V884A

and

V884B,

which

is

triggered

at

the

line

frequency

by

a

6.3-volt

ac

signal

applied

to

the

cathode

of

V884A.

The

signal

at

the

cathode

of

V884A

switches

the

multivibrator

between

its

two

states.

When

V884A

is

conducting,

the

low

voltage

at

its

plate

cuts

off

V884B.

Or,

when

V884B

is

conducting,

its

low

plate

voltage

lowers

the

grid

voltage

of

V884A

sufficiently

to

cut

V884A

off.

Thus,

both

tubes

do

not

conduct

at

the

same

time.

When

V884A

is

cut

off,

the

voltage

at

the

control

grid

and

cathode

of

V884B

is

determined

by

the

setting

of

the

CAL

AMPL

control, R871.

This

determines

the

maximum

voltage

level

reached

by

the

square-wave

output.

The

square

waves

start

at

ground

at

the

time

V884B

is

cut

off

and

reach

the

maximum

amplitude

established

by

R871

when

V884A

is

cut

off.

The

CAL

AMPL

control

is

adjusted

to

give

the

appropriate

output

square-wave

amplitudes

via

the

output

divider

R885

through

R889.

Amplitude

Calibrator

(S/N

300-2049)

R890

was

added

at

S/N

300

so

the

0.5

output

jack

will

provide

a

100-mv

peak-to-peak

signal

into

50

ohms.

No

other

alterations

were

made

and

the circuit

description

is

the

same

as

above.

SECTION

4

MAINTENANCE

Visual

Inspection

If

trouble

occurs

in

the

Type

567,

make

sure

the

associated

equipment

is

operating

and

the

controls

are

properly

set.

If

it

is

determined

that

the

trouble

is

definitely

in

the

Type

567,

a

visual

check

may

reveal

the

cause.

Defects

such

as

loose

or

broken

connections,

frayed

or

broken

cables,

dam-

aged

connectors,

and

burned

components

can

generally

be

detected

by

a

visual

inspection.

Except

for

heat-damaged

components

the

remedy

for

such

defects

is

obvious.

Over-

heating

of

components

is

usually

a

symptom

of

other,

less

apparent

troubles

in

the

circuit.

For

this

reason,

it

is

essen-

tial

to

determine

the

actual

cause

of

overheating

before

the

damaged

parts are

replaced;

otherwise,

the

damage

may

be

repeated.

Parts

Removal

and

Replacement

Whenever

a

part

is

replaced,

check

and

adjust

the

instru-

ment

calibration

as

necessary.

Most

parts

in

the

Type

567

can

be

replaced

without

detailed

instructions.

Some,

how-

ever,

are

best

removed

and

replaced

by

using

definite

pro-

cedures

contained

in

the

following

paragraphs.

(Parts

order-

ing

information

is

included

in

the

Parts

List

section

of

this

manual.}

CAUTION

Turn

ac

power

off

before

removing

tubes

or

transis-

tors

from

their

sockets.

Transistor

Replacement.

Transistors

should

not

be

re-

placed

unless

they

are

actually

defective.

Transistor

defects

usually

take

the

form

of

the

transistor

opening,

shorting,

or

developing

excessive

leakage.

To

check

a

transistor

for

these

and

other

defects,

use

a

transistor

curve

display

instru-

ment

such

as

a

Tektronix

Type

575.

However,

if

a

good

transistor

checker

is

not

readily

available,

a

defective

NPN

or

PNP

TRANSISTOR

Emitter-to-

Collector

Voltage

Emitter-to-Base

Voltage

Fig.

4-1.

In-circuit

voltage

checks

NPN

or

PNP

transistors.

transistor

can

be

found

by

signal-tracing,

by

making

in-

circuit

voltage

checks,

by

measuring

the

transistor

forward-

to-back

resistance

using

proper

ohmmeter

resistances,

or

by

using

the

substitution

method.

The

location

of

all

transis-

tors

is

silk-screened

on

the

chassis

each

socket.

To

check

transistors

using

a

voltmeter,

measure

the

emitter-

to-base

and

emitter-to-collector

voltages

and

determine

if

the

voltages

are

consistent

with

the

normal

resistances

and

currents

in

the

circuit

(see

Fig.

4-1).

To

check

a

transistor

using

an

ohmmeter,

know

your

ohm-

meter

ranges,

the

currents

they

deliver,

and

the

internal

battery

voltage(s).

!f

your

ohmmeter

does

not

have

suffi-

cient

resistance

in

series

with

its

internal

voltage

source,

ex-

cessive

current

will

flow

through

the

transistor

under

test.

Excessive

current

and/or

high

internal

ohmmeter

source

voltage

may

permanently

damage

the

transistor.

NOTE

As

a

general

rule,

use

the

RX

1k

range

where

the

current

is

usually

limited

to

less

than

2ma

and

the

internal

voltage

is

usually

14%

volts.

You

can

quickly

check

the

current

and

voltage

by

insert-

ing

a

multimeter

between

the

ohmmeter

leads

and

measuring

the

current

and

voltage

for

the

range

you

intend

to

use.

When

you

know

which

ohmmeter

ranges

will

not

harm

the

transistor,

then

use

those

ranges

to

measure

the

resistance

with

the

ohmmeter

connected

both

ways

as

given

in

Table

4-1,

TABLE

4-1

Transistor

Resistance

Checks

Ohmmeter

Connections!

Resistance

Readings

That

Can

Be

Expected

Using

the

R

X

1k

Range

Emitter-Collector

to

around

500

k}.

High

reading

one

way

(about

200

k

or

more}.

Low reading

the

other

way

(about

4002

to

2.5k).

High

reading

one

way

(about

500

k

or

more).

Low

reading

the

other

way

{about

4002

to

25k).

Emitter-Base

Base-Collector

lTest

prods

from

the

ohmmeter

are

first

connected

one

way

to

the

transistor

leads

and

then

the

test

prods

are

reversed

(connected

the

other

way).

Thus,

the

effects

of

the

polarity

reversal

of

the

voltage

applied

from

the

ohmmeter

to

the

transistor

can

be

observed.

'f

there

is

doubt

about

whether

the

transistor

is

good

or

not,

substitute

a

new

transistor,

but

first

be

certain

the

circuit

voltages

applied

to

the

transistor

are

correct

before

making

the

substitution.

When

checking

transistors

by

substitution,

be

sure

that

the

voltages

and

loads

on

the

transistor

are

normal

before

making

the

substitution.

If

a

transistor

is

substituted

without

first

checking

out

the

circuit,

the

new

transistor

may

im-

mediately

be

damaged

by

some

defect

in

the

circuit.

4-1

Maintenance—Type

567

Tube

Replacement.

Tester

checks

on

tubes

used

in

the

Type

567

are

not

recommended.

Tube

testers

sometimes

indicate

a

tube

to

be

defective

when

that

tube

is

operating

satisfactorily

in

a

circuit,

or

they

may

fail

to

indicate

tube

defects

which

affect

the

performance

of

the

circuits.

The

criterion

for

the

usability

of

a

tube

is

whether

or

not

it

works

properly

in

the

circuit.

If it

does

not,

it

should

be

replaced.

Unnecessary

replacement

is

not

only

expensive

but

may

also

require

needless

recalibration

of

the

instrument.

Lamp

Replacement.

The

graticule

illumination

lamps

are

bayonet

Type

44,

6-8

volt

bulbs.

Remove

the

four

bezel

nuts,

lift

away

the

bezel

and

graticule

eyebrow,

and

replace

the

lamps

in

the

normal

manner.

Air

Filter

The

Type

567

Oscilloscope

is

cooled

by

air

drawn

through

a

plastic

disposable

filter

located

at

the

rear

of

the

instru-

ment.

If

the

filter

becomes

excessively

dirty,

it

will

restrict

the

flow

of

air

and

may

cause

overheating.

High

internal

temperatures

will

not

only

reduce

the

lifetime

of

the

instru-

ment

components,

but

may

also

cause

the

thermal

cutout

to

open

at

inconvenient

times.

If

the

oscilloscope

is

wired

for

117

volts,

the

fan

motor

continues

to

run

when

the

thermal

cutout

opens

but

all

other

power

in

the

instrument

is

disconnected.

If

the

instrument

is

wired

for

234

volts,

all

power

in

the

instrument

including

the

fan

is

disconnected

when

the

cutout

opens.

Any

time

that

the

thermal

cutout

opens,

the

filter

should

be

checked

immediately.

When

the

interior

temperature

of

the

instrument

has

returned

to

the

safe

level,

the

thermal

cutout

will

close

to

reapply

power

to

the

instrument.

The

filter

should

be

visually

checked

every

few

weeks.

It

should

be

replaced

at

least

every

three

or

four

months,

and

more

often

if

required.

Fan

Motor

Fan

motor

bearings

have

been

lubricated

at

the

factory

and

should

not

require

further

lubrication

more

often

than

about

every

six

months.

One

or

two

drops

of

light

machine

oil

on

the

bearings

is

adequate.

Removal

of

Panels

The

side,

top,

and

bottom

panels

of

the

Type

567

can

be

removed

separately

for

maintenance

work.

All

panels

are

held

in

place

by

small

coin-slot

fasteners.

To

remove

the

panels,

use

a

screwdriver

or

coin

to

rotate

the

fastener

approximately

two

turns

counterclockwise.

Pull

the

upper

portion

of

the

side

panels

outward

from

the

top.

After

first

releasing

the

fasteners,

the

top

and

bottom

panels

can

be

lifted

off.

Panels

can

be

replaced

by

reversing

the

order

of

their

removal.

Cleaning

The

Type

567

should

be

cleaned

as

often

as

operating

conditions

require.

Accumulation

of

dirt

in

the

instrument

can

cause

overheating

and

component

breakdown.

Dirt

on

components

acts

as

an

insulating

blanket

and

prevents

effi-

cient

heat

dissipation.

It

also

provides

a

possible

electrical

conduction

path.

4-2

Loose

dust

accumulated

on

the

outside

of

the

Type

567

can

be

removed

with

a

cloth

or

small paint

brush.

The

paint

brush

is

particularly

useful

for

dislodging

dust

on

and

around

the

front-panel

controls.

Dirt

which

remains

can

be

removed

with

a

soft

cloth

dampened

in

a

mild

solution

of

water

and

detergent.

Abrasive

cleaners should

not

be

used.

The

high-voltage

circuits,

including

parts

located

under

the

high-voltage

shield,

should

receive

special

attention.

Ex-

cessive

dust

and

dirt

in

these

areas

may

cause

high-voltage

arcing

and

result

in

improper

instrument

operation.

CAUTION

Avoid

the use

of

chemical

cleaning

agents

which

might

damage

the

plastics

used

in

this

instrument.

Some

chemicals

to

avoid

are

benzene,

toluene,

zylene,

acetone,

or

similar

solvents.

To

clean

the

crt

protector

plate

and

the

face

of

the

crt,

first

remove

the

four

bezel

mounting

nuts.

Then,

remove

the

bezel

and

the

protector

plate.

Clean

all

surfaces

with

a

soft,

lint-free

cloth

dampened

with

mild

detergent

and

water.

Repeat

with

a

cloth

dampened

with

water

only.

Recalibration

To

assure

accurate

measurements

check

the

calibration

of

this

instrument

after

each

500

hours

of

operation

or

every

six

months

if

used

intermittently.

Complete

calibration

instructions

are

given

in

Section

5.

The

calibration

procedure

can

also

be

helpful

in

localizing

certain

troubles

in

the

instrument.

In

some

cases,

minor

troubles,

not

apparent

during

normal

use,

may

be

revealed

and/or

corrected

by

recalibration.

Resistor

Coding

The

Type

567

uses

a

number

of

very

stable

metal

film

resistors

identified

by

their

gray

background

color

and

color

coding.

If

the

resistor

has

three

significant

figures

with

a

multiplier,

the

resistor

will

be

EIA

color

coded.

If

it

has

four

significant

figures

with

a

multiplier,

the

value

will

be

printed

on

the

resistor.

For

example,

a

333-k

resistor

will

be

color

coded,

but

a

333.5-k

resistor

will

have

its

value

printed

on

the

resistor

body.

The

color-coding

sequence

is

shown

in

Fig.

4-2,

and Table

4-2.

e—

Ist

Sig.

Fig.

2nd

Sig.

Fig.

3rd

Sig.

Fig.

Multiplier

Tolerance

Date

Code

Fig.

4-2.

Standard

EIA

color

code

for

metal

film

resistors.

Tektronix 567 User manual

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