Tektronix 114 User manual

INSTRUCTION

MANUAL

Serial

Number

_____________

114

PULSE

GENERATOR

Tektronix,

Inc.

S.W.

,

Millikan

Way

•

P.

O.

Box

500

•

Beaverton,

Oregon

97005

•

Phone

644-0161

•

ables:

Tektronix

070-465

265

WARRANTY

All

Tektronix

instruments

are

warranted

against

defective

materials

and

workman



ship

for

one

yeor.

Tektronix

transformers,

manufactured

in

our

own

plant,

are

war



ranted

for

the

life

of

the

instrument.

Any

questions

with

respect

to

the

war



ranty

mentioned

above

should

be

taken

up

with

your

Tektronix

Field

Engineer.

Tektronix

repair

and

replacement-part

service

is

geared

directly

to

the

field,

there



fore

all

requests

for

repairs

and

replace



ment

parts

should

be

directed

to

the

Tek



tronix

Field

Office

or

Representative

in

your

area.

This

procedure

will

assure

you

the

fastest

possible

service.

Please

include

the

instrument

Type

and

Serial

number

with

all

requests

for

parts

or

service.

Specifications

and

price

change

priv



ileges

reserved.

opyright

,c

1965

by

Tektronix,

Inc.,

Beaverton,

Oregon.

Printed

in

the

United

States

of

America.

All

rights

reserved.

ontents

of

this

publication

may

not

be

reproduced

in

any

form

without

permis



sion

of

the

copyright

owner.

Type

114

Type

114

Type

114

Pulse

Genero or

-

7

r

CONTENTS

Warranty

Section

1

haracteristics

Section

2

Operating

Instructions

Section

3

ircuit

Description

Section

4

Maintenance

and

alibration

Section

5

Parts

List

and

Diagrams

A

list

of

abbreviations

and

symbols

used

in

this

manual

will

be

found

on

page

5-1.

hange

in



formation,

if

any,

is

located

at

the

rear

of

the

manual.

Type

114

SECTION

1

CHARACTERISTICS

In roduc ion

The

Type

114

Pulse

Generator

is

a

general

purpose

pulse

generator.

Transistorized

circuitry

is

used

throughout,

with

most

of

the

components

being

mounted

on

an

etched

circuit

board.

The

Type

114

Pulse

Generator

is

versatile.

The

repetition

rate,

width,

and

amplitude

of

the

output

pulse

are

individual



ly

selectable

by

range

and

by

variable

control

within

each

range.

Front-panel

connectors

are

provided

for

the

pulse

out



put,

trigger

output,

and

external

trigger

input.

A

single

front



panel

switch

selects

both

the

amplitude

range

and

polarity

of

the

output

pulse.

The

trigger

output

pulse

is

set

by

a

front



panel

switch

to

occur

on

the

desired

edge

(leading

or

trailing)

of

the

output

pulse.

In

cases

where

the

Type

114

is

set

for

a

pulse

width

longer

than

the

pulse

repetition

period,

a

built-

in

feature

automatically

counts

down

the

repetition

rate

to

permit

the

width

of

the

output

pulse

to

remain

at

the

value

selected

(such

operation

is

indicated

by

a

Width

>

Period

light).

In

addition,

two

Type

114's

can

be

connected

together

so

that

the

output

pulse

of

the

second

unit

is

delayed

by

the

pulse

width

(up

to

10

ms)

of

the

first

unit.

short

circuiting

the

OUTPUT

connector

will

not

damage

the

instrument.

WARNING

The

Type

114

should

never

be

connected

to

an

inductive

load,

or

any

load

that

will

produce

a

current

which

will

feed

back

into

the

instrument.

TABLE

1-1

Amplitude

Range

Pulse

on

Pulse

off

±1

to

3

V

≈

20

Ω

19

Ω

to

22

Ω

±3

to

10

V

28

Ω

to

48

Ω

30

Ω

to

95

Ω

Elec rical

Pulse

Period.

The

PERIOD

switch

and

associated

VARI



ABLE

control

provide

continuously

variable

pulse

periods

from

1

µ

sec

to

100

msec

(pulse

repetition

rates

from

one

mil



lion

pulses

per

second

to

10

pulses

per

second).

An

EXTER



NAL

TRIGGER

position

on

the

PERIOD

switch

permits

exter



nal

control

of

the

pulse

period.

With

the

VARIABLE

control

at

the

AL

end

of

its

range

and

the

WIDTH

>

PERIOD

light

unlit,

the

period

accuracy

is

within

±3%

of

the

indicated

value.

Jitter

is

typically

less

than

0.05%

of

pulse

period

+2

ms.

Pulse

Wid h.

The

WIDTH

switch

and

associated

VARI



ABLE

control

provide

continuously

variable

pulse

widths

from

l

00 n

sec

to

10

msec.

With

the

width

VARIABLE

control

at

the

AL

end

of

its

range,

the

width

accuracy

is

within

±3%

of

indicated

value.

Jitter

is

typically

less

than

0.05%

plus

½

nsec.

An

additional

SQUARE

WAVE

position

on

the

WIDTH

switch

disables

the

variable

width

feature

and

changes

the

output

to

a

square

wave

whose

repetition

rate

is

determined

by

the

PERIOD

controls.

Period

error

in

the

square

wave

mode

is

<

±5%.

Ou pu

Polari y

and

Ampli ude.

The

AMPLITUDE

switch

provides

for

either

polarity

output

with

two

amplitude

ranges

(1

V

to

3

V

and

3

V

to

10

V).

The

VARIABLE

control

permits

the

output

to

be

varied

within

the

voltage

ranges.

Aber



rations

(overshoot,

rolloff,

preshoot,

or

ringing)

amount

to

less

than

5%

at

maximum

amplitude.

Ou pu

Impedance.

The

output

impedance

of

the

Type

114

is

given

in

Table

1-1.

The

figures

given

are

typical

and

are

dependent

upon

the

setting

of

the

AMPLITUDE

—

VARI



ABLE

control.

Load

impedance

is

not

critical.

Temporarily

Ex ernal

Trigger

Inpu .

External

triggering

requires

a

positive

trigger

signal

of

2

to

20

volts

and

having

a

risetime

of

1

µ

sec

or

less.

Triggering

signals

up

to

2

Mc

may

be

used.

Trigger

Ou pu .

The

trigger

output

pulse

into

an

open

circuit

is

approximately

3

volts;

into

a

50

Ω

termination,

the

trigger

output

pulse

is

approximately

'/

2

volt.

A

front-panel

switch

allows

the

output

trigger

pulse

to

be

set

to

occur

at

the

leading

edge

or

the

trailing

edge

of

the

main

pulse.

Inpu

Power

Requiremen s.

≈

15

watts;

50

to

400

cps,

94.5

to

137.5

or

189

to

275

volts,

ac.

Warm-up

Time

at

+25°

±5° .

Five

minutes

for

rated

accuracies.

Environmen al

Opera ing

Temperature

Altitude

Non-Opera ing

Temperature

Altitude

Mechanical

Dimensions

onnectors

Accessories

0°

to

+50°

15,000

feet

maximum

—

40°

to

+65°

50,000

feet

maximum

Approximately

9"

X

6"

X

12

½"

overall

Front-panel

connectors

are

BN

type.

See

standard

accessory

lists

in

this

manual

for

accessories

supplied

with

each

instrument.

For

optional

accessories,

see

the

current

Tektronix,

Inc.

catalog.

1-1

Charac eris ics

—

Type

114

GLOSSARY

OF

TERMS

MPPS

Bistable

(multivibrator)

alibrate

A

circuit

that

has

two

stable

states

and

requires

two

input

pulses

to

complete

a

cycle.

To

check

or

correct

the

graduation

ac



curacy

of

quantitative

indicators.

AL

(calibrated)

position

An

index

position

to

which

an

otherwise

ungraduated

control

is

set

when

a

quanti



tative

measurement

must

be

made.

atching

or

clamping

diode

Establishes

the

+

or

—

extremity

of

a

volt



age

excursion.

ount-down

(of

pulses)

circuit

Delayed

pulse

Overshoot

PPS

Preshoot

Pulse

amplitude

Pulse

duration

A

circuit,

such

as

a

bistable,

whose

output

consists

of

pulses

fewer

in

number

(usu



ally

a

submultiple)

than

the

pulses

applied

to

the

input(s).

A

pulse

occurring

after

a

preselected

in



terval

following

an

event

used

as

a

time

reference

point.

Delayed

trigger

Duty

factor

(of

pulses)

Enabling

pulse

External

trig



ger

(pulse)

Falltime

Generally,

a

narrow,

delayed

pulse.

For

periodic

pulses,

the

duty

factor

(often

called

duty

cycle)

is

equal

to

the

duration

(width)

of

a

pulse

divided

by

the

pulse

period.

A

pulse

which

opens

a

normally

closed

electric

gate,

or

otherwise

permits

an

oper



ation

for

which

a

pulse

input

is

a

neces



sary

condition.

An

enabling

pulse

derived

from

a

source

external

to

the

circuit

or

equipment

where

a

particular

operation

requires

an

enabling

pulse

with

certain

characteristics

(time

de



layed,

duration,

etc.).

The

time

required

by

pulse

waveform

to

fall

from

90%

of

its

maximum

value

to

10%

of

its

maximum

value.

Not

neces



sarily

equal

to

risetime.

Jitter

KPPS

Pulse

period

Pulse

Repeti



tion

Frequency

Pulse

width

Quiescent

Ramp

voltage

Ringing

Risetime

Short-duration

instability

(of

a

signal);

ran



dom

small

departures

from

regularity.

Kilopulses

per

second.

Monostable

(multivibrator)

A

circuit

having

one

stable

and

one

semi



stable

state.

A

trigger

pulse

drives

the

circuit

into

the

semistable

state,

where

it

remains

for

a

predetermined

time

before

returning

to

the

stable

condition.

Sampling

system

Trigger

Megapulses

per

second.

When

changing

from

one

voltage

level

to

another,

a

momentary

excursion

greater

than

the

change

desired.

Pulses

per

second.

A

small

negative

excursion

immediately

preceding

a

positive-going

pulse,

or

vice

versa.

The

amplitude

of

a

pulse

is

any

term

indi



cating

the

magnitude

of

the

pulse.

The

time

interval

between

the

first

and

last

instants

at

which

the

pulse

voltage

(or

current)

reaches

some

specified

percentage

of

the

peak

voltage

(or

current)

of

the

pulse.

The

pulse

period

in

a

sequence

of

periodic

pulses

is

the

elapsed

time

between

any

given

point

on

one

of

the

pulse

waveforms

and

the

same

point

on

the

following

pulse.

The

number

of

periodic

pulses

that

occur

in

a

given

unit

of

time.

Also

expressed

as

pulse

repetition

rate.

See

pulse

duration.

At

rest

—

specifically,

the

condition

of

a

circuit

when

no

input

signal

is

being

ap



plied

and/or

no

change

is

taking

place.

A

voltage

waveform

that

rises

at

a

steady

rate.

For

example,

at

10

volts

per

second..

High-frequency

damped

oscillations

caused

by

shock

excitation

of

high-frequency

res



onances,

or,

a

damped

oscillation

in

the

output

signal

of

a

system

as

a

result

of

a

sudden

change

in

the

input

signal.

The

risetime

of

a

pulse

is

taken

as

the

time

required

for

the

leading

edge

of

the

pulse

to

increase

from

10%

of

its

maximum

value

to

90%

of

its

maximum

value.

A

method

that

takes

amplitude

samples

from

a

repetitive

input

signal

with

each

sample

at

a

progressively

later

time,

then

reconstructs

these

samples

into

a

replica

of

the

original

waveform

at

a

much

lower

frequency.

A

signal

that

starts

action

in

another

circuit.

1-2

SECTION

2

OPERATING

INSTRUCTIONS

Fron -Panel

Con rols,

Indica ors,

and

Connec ors

(See

Fig.

2-1.)

The

function

of

each

item

on

the

Type

114

front

panel

is

given

in

the

following

tabulation.

POWER

Switch

This

toggle

switch

completes

the

circuit

to

the

primary

of

the

power

transformer.

Indicator

The

white

lamp

to

the

right

of

the

POWER

switch

lights

when

the

Type

114

is

en



ergized.

PERIOD

Switch

This

switch

selects

the

basic

range

of

pulse

period.

When

the

switch

is

set

to

EXTERNAL

TRIGGER

—

INPUT,

the

Type

114

provides

width

and

amplitude

control

for

externally

generated

pulses

applied

to

the

INPUT

connector.

Note

that

“

100

mS"

does

no

indicate

a

switch

position,

but

is

instead

an

index

for

the

VARIABLE

control.

VARIABLE

This

control

has

a

range

of

10:1

or

more,

ontrol

and

provides

continuous

coverage

between

the

steps

of

the

PERIOD

switch.

EXTERNAL

BN

connector

to

which

the

external

trig-

TRIGGER-

ger

is

applied

when

externally

triggering.

INPUT

on



nector

WIDTH

Switch

This

switch

selects

the

basic

ranges

of

pulse

width.

Note

that

the

word

“

10

mS

”

does

no

indicate

a

switch

position,

but

is

instead

an

index

for

the

associated

VARI



ABLE

control.

When

the

WIDTH

switch

is

set

to

SQUARE

WAVE,

the

output

of

the

Type

114

is

a

square

wave

whose

period

is

selected

by

the

PERIOD

controls.

VARIABLE

This

control

provides

continuous

cover-

ontrol

age

between

the

steps

of

the

WIDTH

switch

and

has

a

range

of

10:1

or

greater.

WIDTH

>

With

the

flexibility

provided,

it

is

possible

PERIOD

In-

to

set

the

controls

so

that

the

width

of

the

dicator

light

pulse

selected

exceeds

the

period

selected.

When

this

occurs,

the

Type

114

counts

down

the

repetition

rate

and

lights

the

WIDTH

>

PERIOD

light.

The

pulse

width

remains

as

selected,

but

the

pulse

period

is

no

longer

that

selected

by

the

PERIOD

controls.

AMPLITUDE

Switch

Selects

the

two

basic

voltage

ranges

and

the

polarity

of

the

output

signal.

VARIABLE

Provides

for

varying

the

output

amplitude

ontrol

within

the

range

selected

by

the

AMPLI



TUDE

switch.

OUTPUT

Connec or

BN

connector

from

which

the

output

is

taken.

TRIGGER

Switch

This

switch

permits

the

operator

to

select

the

edge

of

the

output

pulse

at

which

the

trigger

pulse

occurs.

onnector

BN

connector

from

which

the

trigger

pulse

output

is

taken.

Firs

Time

Opera ion

The

following

procedures

are

designed

to

acquaint

the

operator

with

the

operation

of

the

Type

114.

1.

Set

the

three

VARIABLE

controls

extreme

counterclock



wise.

Set

the

PERIOD

switch

to

100 µ

S,

the

WIDTH

switch

to

SQUARE

WAVE,

and

the

AMPLITUDE

switch

to

the

"

+

1

TO

+3

V"

position.

2.

onnect

the

OUTPUT

connector

of

the

Type

114

to

the

vertical

input

of

an

oscilloscope

(Tektronix

Type

547/1

Al

or

equivalent)

by

means

of

a

50

ft

coaxial

cable.

Terminate

the

coaxial

cable

at

the

oscilloscope

end

with

a

50

ft

ter



mination

(Tektronix

Part

No.

011-049

or

equivalent).

Make

sure

the

input

voltage

switch

is

set

to

match

the

voltage

of

the

power

source

in

use

(115

or

230

V

ac).

See

Fig.

2-2.

At



tach

the

power

cord.

3.

Apply

power

to

the

Type

114

and

the

oscilloscope.

Set

the

oscilloscope

TIME/DIV

or

TIME/ M

switch

to

.1

mSE

and

obtain

a

stable

display.

4.

Set

the

WIDTH

switch

to

10

µ

S.

Turn

the

associated

VARIABLE

control

clockwise

and

note

the

increase

in

pulse

width.

When

the

control

is

turned

so

that

the

pulse

width

exceeds

100

/

j

.S,

the

WIDTH

>

PERIOD

lamp

lights.

5.

Operate

the

PERIOD,

WIDTH,

and

AMPLITUDE

switches

and

controls

throughout

their

ranges

and

check

the

results

with

the

oscilloscope.

Using

he

Type

114

as

a

Source

of

Delayed

Trigger

The

use

of

the

Type

114

as

a

source

of

delayed

trigger

may

be

demonstrated

as

follows:

1.

Apply

a

1

Kpps

signal

(such

as

the

output

of

the

oscillo



scope

calibrator)

through

a

BN

T

connector

and

appro



priate

coax

cables

to

the

external

trigger

input

connectors

of

2-1

Opera ing

Ins ruc ions

—

Type

114

Fig.

2-1.

Fron

panel

con rol*.

Fig.

2-2.

Type

114

rear

pon

e

l.

2-2

Opera ing

Ins ruc ions

—

Type

114

both

the

Type

114

and

the

oscilloscope

(see

Section

1

for

external

trigger

characteristics

required).

2.

Obtain

an

externally

triggered

sweep

on

the

oscillo



scope.

3.

onnect

a

coaxial

cable

between

the

TRIGGER

OUT



PUT

connector

of

the

Type

114

and

the

vertical

input

of

the

oscilloscope.

4.

Turn

the

Type

114

PERIOD

switch

to

EXTERNAL

TRIG



GER.

Set

the

WIDTH

switch

to

100

µ

S.

Turn

the

WIDTH

variable

control

to

AL.

Set

the

oscilloscope

VOLTS/ M

switch

to

1

volt.

Set

the

TIME/ M

switch

to

.1

mSE .

5.

Set

the

Type

114

TRIGGER

switch

to

TRAILING

EDGE.

A

narrow

trigger

pulse

approximately

3

volts

in

amplitude

should

be

visible

approximately

1

cm

from

the

start

of

the

oscilloscope

trace.

6.

Turn

the

WIDTH

—

VARIABLE

control

and

note

that

the

displayed

trigger

pulse

can

be

delayed

from

10 µ

sec

to

more

than

100

µ

sec

from

the

start

of

the

trace.

By

using

the

5

basic

ranges

of

the

WIDTH

switch

and

by

turning

the

as



sociated

VARIABLE

control,

it

is

possible

to

delay

the

trigger

pulse

over

a

range

from

approximately

150

nanoseconds

to

10

milliseconds.

Swi ching

he

Power

Transformer

Primary

Con



nec ions

A

switch

on

the

rear

of

the

Type

114

chassis

permits

switching

the

power

transformer

connections

for

operation

on

either

94.5-137.5

(115

V

ac

nominal)

or

189-275

volts

ac

(230

V

ac

nominal).

Be

sure

the

correct

fuse

is

installed.

2-3

NOTES

SECTION

3

CIRCUIT

DESCRIPTION

In roduc ion

This

section

contains

the

theory

of

operation

of

the

various

circuits

in

the

Type

114.

The

text

is

supplemented

by

two

block

diagrams

inserted

in

the

text

and

by

schematics

in

Section

5.

The

reader

should

follow

the

circuits

on

the

dia



grams

as

they

are

presented

in

the

text.

AUTION

There

is

no

fixed

chassis

ground

for

the

circuit

board

used

in

the

Type

114.

A

common

negative

point

is

used

instead.

This

permits

changing

the

polarity

of

the

output

by

grounding

the

appro



priate

side

of

the

power

supply.

For

this

reason,

always

connect

probe

grounds

to

the

main

chassis

rather

than

to

a

point

on

the

circuit

board.

Period

Genera or

The

Period

Generator

(see

Fig.

3-1)

supplies

the

trigger

pulse

which

activates

the

Width

Generator.

The

trigger

pulse

is

generated

internally,

or

is

derived

from

an

externally

gen



erated

triggering

signal,

depending

upon

the

setting

of

the

PERIOD

switch.

In ernal

Opera ion.

When

the

Type

114

is

operating

in

the

internally

triggered

modes,

the

operation

of

the

Period

Generator

is

as

follows:

Transistors

Q

1

15

and

Q125

in

conjunction

with

the

ap



propriate

R

timing

combination

form

a

free

running

oscil



lator.

At

the

start

of

a

cycle

of

operation,

Q

1

15

is

biased

off

and

Q125

is

biased

slightly

on.

The

charge

on

timing

ca



pacitor

1

15

has

been

removed

by

the

preceding

cycle

and

now

starts

charging

toward

a

common

point

voltage

at

an

R

rate.

As

the

timing

capacitor

charges,

the

voltage

across

it

reaches

a

point

where

it

turns

on

diode

D

1

14

and

transistor

Q

1

15.

At

this

instant

the

circuit

becomes

regenerative

with

Q

1

15

turning

Q125

on

hard,

which

in

turn

biases

Q

1

15

into

heavy

conduction.

The

heavy

conduction

of

Q

1

15

removes

the

charge

accumulated

on

timing

capacitor

1

15

and

ends

the

cycle.

At

the

instant

Q

1

25

is

turned

on

hard

by

Q

1

15,

the

steep

wave-front

is

coupled

through

R131

and

1

31

to

the

base

of

Q

1

34,

and

thence

to

pulse

transformer

T131.

The

pulse

out



put

of

T131

is

in

the

order

of

20

nanoseconds

in

width.

Ex ernal

Trigger

Opera ion.

When

the

Type

114

is

op



erating

in

the

externally

triggered

mode,

the

Pulse

Generator

functions

as

a

pulse

shaper.

Period

switch

SW120

discon



nects

the

base

of

Q

1

15

from

the

collector

of

Q

1

25

and

re



connects

it

to

the

external

trigger

input

circuit.

SW120

also

connects

the

base

of

Q

1

25

to

+25

volts

through

R121

and

disconnects

the

timing

capacitor

from

the

circuit.

Under

these

conditions

none

of

the

transistors

in

the

Period

Gen



erator

are

conducting.

A

positive

pulse

of

2

to

20

volts

in

amplitude

and

having

a

risetime

of

1

microsecond

or

less

is

required

at

the

EXTERNAL

TRIGGER

—

INPUT

connector

in

order

to

make

the

transistors

conduct

and

deliver

the

proper

pulse

to

the

Width

Generator.

When

a

pulse

having

the

proper

amplitude

and

risetime

is

applied

to

the

EXTERNAL

TRIGGER

—

INPUT

connector,

Q

1

15

is

biased

into

conduction

and

in

turn

biases

Q

1

25

and

Q134

into

conduction.

The

resulting

pulse

at

the

pri



mary

of

T131

has

a

risetime

of

about

10

nanoseconds.

Wid h

Genera or

The

Width

Generator

receives

the

trigger

pulses

from

T131

and

generates

pulses

of

the

desired

width.

The

out



put

of

the

width

generator

is

applied

to

the

Trigger

Out

ircuit

and

to

the

Output

Amplifier.

Except

when

operat



ing

in

the

square

wave

mode,

the

Width

Generator

operates

as

a

monostable

multivibrator;

in

the

square

wave

mode

the

Width

Generator

functions

as

a

bistable.

Normal

Opera ion.

In

normal

operation

transistors

Q205

and

Q215

form

a

bistable

network

whose

output

drives

ramp

transistor

Q224,

trigger

output

transistor

Q234,

and

the

output

amplifier.

Q205

is

the

normally

“

on"

tran



sistor.

The

arrival

of

a

negative

trigger

pulse

from

T131

cuts

off

Q205.

Q215

now

conducts

and

cuts

off

Q224,

permitting

the

voltage

at

the

collector

of

Q224

to

start

charging

ramp

capacitor

1

95.

When

the

selected

ramp

capacitor

reaches

the

desired

voltage,

D

1

93

is

forward

biased

and

transistor

Q

1

94

is

biased

into

conduction.

The

conduction

of

Q

1

94

increases

the

conduction

of

Q

1

84

and

thereby

biases

Q205

back

into

conduction.

The

conduction

of

Q205

ends

the

output

pulse.

Turning

on

Q205

turns

off

Q215

and

turns

on

Q224.

The

conduction

of

Q224

dis



charges

the

ramp

capacitor.

When

the

ramp

capacitor

is

discharged

down

to

about

0.3

volt,

Q174

turns

off

and

Q164

is

turned

on.

Transistors

Q

1

64

and

Q

1

74,

diodes

D

1

36

and

D

16

1,

and

pulse

trans



former

T131

function

as

a

pulse

steering

circuit.

With

Q

1

64

on,

the

pulse

from

the

Period

Generator

via

T131

triggers

the

width

monostable

circuit

on,

generating

an

output

pulse.

As

soon

as

the

ramp

capacitor

reaches

approximately

0.3

volt,

Q174

conducts

and

turns

Q164

off.

Turning

off

Q164

reverse

biases

D

1

61,

while

turning

on

Q

1

74

biases

D

1

36

near

zero.

If

the

Period

Generator

produces

a

pulse

while

these

conditions

exist,

that

is,

whenever

the

ramp

capacitor

has

a

charge

above

approximately

0.3

volt,

the

pulse

is

steered

to

the

WIDTH

>

PERIOD

light

circuit.

This

mono



stable

circuit

is

actuated

by

the

pulse

from

T131,

turning

off

Q145

and

turning

Q155

on,

lighting

the

WIDTH

>

PERIOD

light.

Turning

on

Q

1

55

causes

1

55

to

discharge

through

T131

and

R136.

When

155

is

discharged,

D141

and

Q

1

45

conduct

and

reset

the

circuit,

making

it

ready

for

another

pulse.

Square

Wave

Mode.

When

the

Type

114

is

operated

in

the

Square

Wave

Mode

(see

Fig.

3-2),

the

Width

Gen



erator

operates

as

a

bistable

and

requires

two

trigger

pulses

from

the

Period

Generator

for

each

cycle

of

operation.

onsequently,

the

R

network

in

the

Period

Generator

is

3-1

Circui

Descrip ion

—

Type

114

Fig.

3-1.

Type

114

block

configura ion

for

pulse

ou pu .

reduced

to

half

its

normal

value

so

that

the

Period

Gen



erator

can

deliver

twice

the

usual

number

of

output

pulses.

This

procedure

ensures

that

the

period

indicated

by

the

PERIOD

switch

remains

valid

for

square-wave

operation.

(When

external

triggering

is

used,

the

period

of

the

square

wave

is

twice

that

of

the

triggering

signal,

since

the

Width

Generator

is

functioning

as

a

bistable

and

requires

two

pulses

for

each

cycle

of

operation.)

In

the

Width

Generator,

the

ramp

circuit

is

disabled

by

D

1

96,

which

means

that

the

comparator

consisting

of

D

1

93,

Q

1

94,

and

Q

1

84

is

not

used.

Resetting

of

the

width

bistable

is

accomplished

by

applying

the

output

of

WIDTH

>

PERI



OD

light

driver

transistor

Q155

to

the

base

of

Q125.

At

the

instant

of

turn

on

when

operating

in

the

square



wave

mode,

D

1

77

reverse

biases

and

Q

1

74

is

biased

on.

Q

1

74

turns

off

Q

1

64

and

zero

biases

steering

diode

D

1

36.

Under

these

conditions,

the

first

pulse

from

the

Period

Gen



erator

forward

biases

D

1

36

and

turns

off

Q

1

45.

Turning

off

Q

1

45

turns

on

Q

1

55,

which

in

turn

cuts

off

Q215

and

makes

Q205

the

conducting

transistor

in

the

bistable.

Turning

off

Q215

also

biases

Q224

into

conduction

which

switches

the

steering

circuit

so

that

D

1

61

becomes

zero

biased.

The

second

pulse

from

the

Period

Generator

is

steered

to

Q205,

switching

the

bistable

and

the

steering

circuit.

Thus

the

output

of

the

bistable

is

a

symmetrical

square

wave.

Trigger

Ou pu

Circui

Trigger

output

transistor

Q234

normally

operates

in

satura



tion

due

to

the

current

through

R232.

Whenever

the

sig



nal

selected

by

the

TRIGGER

switch

goes

negative,

the

volt



age

change

is

coupled

through

231

to

the

base

of

Q234

and

momentarily

takes

it

out

of

saturation.

When

this

hap



pens,

the

collector

voltage

of

Q234

rises

sharply

until

it

reaches

≈

3

½

volts

and

forward

biases

catcher

diode

D236.

The

resulting

trigger

output

through

236

is

about

80

nanoseconds

wide

and

is

limited

to

≈

+3

volts

into

an

open

circuit,

or

to

10

ma

into

a

short

circuit.

The

TRIGGER

switch

permits

selecting

the

edge

of

the

output

waveform

at

which

the

trigger

occurs.

By

setting

the

switch

to

TRAILING

EDGE,

the

Type

114

may

be

used

as

a

delay

generator

with

the

WIDTH

controls

setting

the

amount

of

delay.

Ou pu

Amplifier

The

two-stage

output

amplifier

consists

of

driver

transistor

Q244

and

the

parallel-connected

output

transistors

Q254

and

Q264.

When

negative

output

pulses

are

desired,

the

output

transistors

are

connected

common

emitter

and

the

+25-volt

supply

is

connected

to

chassis

ground

displacing

the

circuit

board

common

ground

25

volts

negative.

When

positive

output

pulses

are

desired,

the

output

transistors

are

connected

as

an

emitter

follower

and

the

common

point

is

connected

to

chassis

ground.

Polarity

switching

of

the

out



put

is

accomplished

by

the

AMPLITUDE

switch.

3-2

Circui

Descrip ion

—

Type

114

Fig.

3-2.

Type

114

block

configuration

for

square-wave

output.

AUTION

Do

not

connect

test

probe

ground

clips

to

the

com



mon

point

of

the

circuit

board

while

the

AMPLI



TUDE

switch

is

in

either

of

the

negative

positions.

The

best

procedure

is

to

always

connect

the

test

probe

ground

clip

to

the

main

chassis

and

leave

the

AMPLITUDE

switch

in

the

positive

output

posi



tions.

The

VARIABLE

control

associated

with

the

AMPLITUDE

switch

provides

continuously

variable

voltage

amplitude

within

the

ranges

of

the

AMPLITUDE

switch.

Power

Supply

The

power

supply

consists

of

a

regulated

25-volt

supply

and

an

unregulated

35-volt

supply.

The

25-volt

supply

and

a

10-volt

supply

are

stacked

to

obtain

the

35-volt

supply.

A

rear-panel

switch

is

provided

to

change

transformer

pri



mary

connections

when

switching

from

115-

to

230-volt

operation.

®L

3-3

EXTERNAL

TRIGGER

INPUT

Width

>

Period

ircuit

Q

1

45,

Q

1

55

Period

Generator

Q

1

15,

Q125,

Q

1

34

Steering

ircuit

T131,

D136,

D161,

Q

1

64

Q

1

74

Q224

Output

Amplifier

Q244,

Q254,

Q264

Width

Bistable

Q2

0

5,

Q215

Trigger

Output

ircuit

Q234

OUTPUT

TRIGGER

OUTPUT

NOTES

SECTION

4

MAINTENANCE

AND

CALIBRATION

Preven ive

Main enance

Preventive

maintenance

consists

of

cleaning,

visual

inspec



tion,

lubrication,

and

if

needed,

recalibration.

Preventive

maintenance

is

generally

more

economical

than

corrective

maintenance

since

preventive

maintenance

can

usually

be

done

during

idle

periods

at

a

time

convenient

to

the

user.

The

preventive

maintenance

schedule

established

for

the

instrument

should

be

based

on

the

amount

of

use

and

the

environment

in

which

the

instrument

is

used.

Cleaning.

lean

the

instrument

often

enough

to

prevent

accumulation

of

dirt.

Dirt

on

the

components

acts

as

an

insulating

blanket

(preventing

efficient

heat

dissipation)

and

may

provide

conducting

paths.

lean

the

instrument

by

loosening

the

accumulated

dust

with

a

dry,

soft

paint

brush.

Remove

the

loosened

dust

by

vacuum

and/or

dry,

low

pressure

compressed

air

(high

velocity

air

can

damage

certain

components).

Hardened

dirt

and

grease

may

be

removed

with

a

cotton-tipped

swab

or

a

soft

cloth

dampened

with

water

and

a

mild

detergent

solution

(such

as

Kelite

or

Spray

White).

Abrasive

cleaners

should

not

be

used.

AUTION

Do

not

permit

water

to

get

inside

controls

or

shaft

bushings.

Lubrica ion.

The

life

of

potentiometers

and

rotary

switches

is

lengthened

if

these

devices

are

kept

properly

lubricated.

Use

a

cleaning

type

lubricant

(such

as

ramoline)

on

shaft

bushings

and

switch

contacts.

Lubricate

the

switch

detents

with

a

heavier

grease

(Beacon

grease

No.

325

or

equiva



lent).

Do

not

over-lubricate.

The

necessary

materials

and

instructions

for

proper

lubrication

of

Tektronix

instruments

are

contained

in

a

component

lubrication

kit

which

may

be

ordered

from

Tektronix.

Order

Tektronix

Part

No.

003-342.

Visual

Inspec ion.

After

cleaning,

the

instrument

should

be

carefully

inspected

for

such

defects

as

poor

connections,

damaged

parts,

and

improperly

seated

transistors.

The

rem



edy

for

most

visible

defects

is

obvious;

however,

if

heat



damaged

parts

are

discovered,

determine

the

cause

of

overheating

before

the

damaged

parts

are

replaced.

Other



wise,

the

damage

may

be

repeated.

Transis or

Checks.

Periodic

preventive

maintenance

checks

consisting

only

of

removing

the

transistors

from

the

instrument

and

testing

them

in

a

tester

are

not

recommend



ed.

The

circuits

within

the

instrument

provide

the

most

satisfactory

means

of

checking

transistor

performance.

Per



formance

of

the

circuits

is

thoroughly

checked

during

cali



bration

so

that

substandard

transistors

will

be

detected

at

this

time.

heck

suspect

transistors

by

substitution.

Be

sure

the

substituted

transistor

is

the

same

type

as

the

one

re



placed,

and

that

the

substitute

itself

is

good.

If

the

original

transistor

is

found

to

be

good,

return

it

to

the

same

socket

from

which

removed.

Recalibra ion.

Instrument

accuracy

is

ensured

if

the

cali



bration

of

the

Type

114

is

checked

after

every

500

hours

of

operation

(every

six

months

if

the

instrument

is

used

inter



mittently).

omplete

recalibration

instructions

are

contained

later

in

this

section.

The

calibration

procedure

is

helpful

in

isolating

major

troubles

in

the

instrument.

Moreover,

minor

troubles

not

apparent

during

regular

operation

may

be

revealed

and

corrected

during

recalibration.

Correc ive

Main enance

General

Troubleshoo ing.

If

the

instrument

is

not

op



erating,

attempt

to

isolate

the

trouble

by

a

quick

opera



tional

and

visual

check.

Make

sure

that

any

apparent

trouble

is

actually

due

to

a

malfunction

within

the

Type

114

and

not

due

to

improper

control

settings

or

a

fault

in

associated

equipment.

Operate

the

front-panel

controls

to

see

what

effect,

if

any,

they

have

on

the

trouble

symptoms.

The

normal

or

abnormal

operation

of

each

particular

control

helps

in

establishing

the

nature

of

the

trouble.

The

normal

function

of

each

control

is

listed

in

Section

2

of

this

manual.

If

the

trouble

cannot

be

located

by

means

of

front-panel

checks,

remove

the

instrument

from

its

case

and

check

volt



ages

and

waveforms

against

those

shown

on

the

schematics

in

Section

5,

starting

with

the

power

supply

connections.

Once

the

trouble

is

isolated

to

a

particular

circuit,

refer

to

the

circuit

description

in

Section

3

for

an

explanation

of

how

the

circuit

normally

operates.

AUTION

Be

careful

when

making

measurements

on

live

circuits.

The

small

size

and

high

density

of

com



ponents

used

in

this

instrument

result

in

close

spac



ing.

An

inadvertent

movement

of

the

test

probes,

or

the

use

of

oversized

probes,

may

short

between

circuits.

Helpful

Hin s:

1.

heck

the

voltage

between

chassis

ground

and

the

top

end

of

R244

(333

Ω

10

watt

resistor

mounted

at

the

top-right-rear

of

the

chassis).

With

normal

line

voltage,

the

voltage

at

the

top

of

R244

should

read

31

to

35

volts

if

the

AMPLITUDE

switch

is

set

to

+

;

6

to

10

volts

if

the

switch

is

set

to

—

.

2.

Set

the

AMPLITUDE

switch

to

+

and

turn

off

the

power.

Using

an

ohmmeter,

check

the

resistance

from

the

top

end

of

R244

to

chassis

ground.

If

there

is

no

charge

on

the

filter

capacitors,

the

resistance

reading

should

be

about

800

Ω

to

2

k.

If

it

is

not,

reverse

the

meter

leads

and

re



check.

4-1

Main enance

and

Calibra ion

—

Type

114

Fig.

4-1.

Equipmen

necessary

for

recalibra ing

he

Type

114.

4-2

Main enance

and

Calibra ion

—

Type

114

3.

If

the

voltage

and

resistance

measurements

taken

in

the

proceeding

steps

are

normal,

use

an

oscilloscope

to

check

the

waveforms

at

the

points

shown

on

the

schematics

in

Section

5.

hecking

the

waveforms

will

help

in

isolat



ing

the

trouble

to

a

particular

circuit.

Once

the

trouble

is

isolated

to

a

particular

circuit,

take

voltage

and

resistance

measurements

until

the

defective

component

is

identified.

Componen

Iden ifica ion.

The

circuit

number

of

each

electrical

part

is

shown

on

the

circuit

diagrams

in

Section

5.

Note

that

a

functional

group

of

circuits

(such

as

the

power

supply)

is

assigned

a

particular

series

of

numbers.

Switch

wafers

are

identified

by

counting

from

the

first

wafer

locat



ed

behind

the

detent

section

of

the

switch

towards

the

last

wafer.

The

letters

F

and

R

indicate

whether

the

front

or

rear

of

the

wafer

is

used

to

perform

the

particular

switch



ing

function.

For

example,

the

designation

2R

printed

by

a

switch

section

on

a

schematic

identifies

the

switch

section

as

being

on

the

rear

side

of

the

second

wafer

when

counting

back

from

the

detent

section.

Par s

Replacemen .

Most

of

the

electronic

components

in

the

Type

114

are

standard

items

available

locally.

The

remainder

of

the

electronic

components

and

most

of

the

mechanical

parts

are

manufactured

or

selected

by

Tek-

tronix

to

satisfy

particular

requirements,

or

are

manufac



tured

for

Tektronix

to

our

specifications.

However,

all

parts

are

obtainable

through

your

Tektronix

Field

Engineer

or

Field

Office.

Before

purchasing

or

ordering,

consult

the

Parts

List

(Section

5)

to

determine

the

value,

tolerance,

and

ratings

required.

See

“

Parts

Ordering

Information"

and

"Special

Notes

and

Symbols"

on

the

first

page

of

Sec



tion

5.

When

selecting

the

replacement

parts,

it

is

important

to

remember

that

the

physical

size

and

shape

of

a

com



ponent

may

affect

its

performance

in

the

circuit.

Parts

orientation

and

lead

dress

should

duplicate

those

of

the

original

part,

since

many

of

the

components

are

mounted

in

a

particular

way

to

reduce

or

control

stray

capacitance

and

inductance.

After

repair,

portions

of

the

instrument

may

require

recalibration.

Replacing

Componen s

on

E ched-Circui

Boards.

Use

ordinary

electronic

grade

60/40

solder

and

a

35-

to

40-

watt

pencil

soldering

iron

with

a

'/

8

"

wide

chisel

tip.

The

tip

of

the

iron

should

be

clean

and

properly

tinned

for

best

heat

transfer

in

a

short

time

to

a

soldered

connection.

A

higher

wattage

soldering

iron,

if

used

and

applied

for

too

long

a

time,

ruins

the

bond

between

the

etched

wiring

and

base

material

by

charring

the

glass

epoxy

laminate.

The

step-by-step

technique

is

as

follows:

1.

Remove

the

component

by

cutting

the

leads

near

the

body.

This

frees

the

leads

for

individual

unsoldering.

2.

Grip

the

lead

with

needle-nose

pliers.

Apply

the

tinned

tip

of

a

40-watt

pencil

soldering

iron

to

the

lead

between

the

pliers

and

the

board;

then

pull

gently.

3.

When

the

solder

first

begins

to

melt,

the

lead

will

come

out,

leaving

a

clean

hole.

If

the

hole

is

not

clean,

use

the

soldering

iron

and

a

toothpick

or

a

piece

of

enamel

wire

to

open

the

terminal

hole.

Do

not

attempt

to

drill

the

solder

out

since

the

"through-hole"

plating

might

be

de



stroyed.

4.

lean

the

leads

on

the

new

component

and

bend

them

to

the

correct

shape.

arefully

insert

the

leads

into

the

holes

from

which

the

defective

component

was

removed.

5.

Apply

the

iron

for

a

short

time

at

each

connection

on

the

side

of

the

board

opposite

the

component

to

properly

seat

the

component.

6.

Apply

the

iron

and

a

little

solder

to

the

connections

to

finish

the

solder

joint.

Calibra ion

and

Verifica ion

Recalibrate

the

Type

114

after

each

500

hours

of

opera



tion,

or

every

six

months

if

used

intermittently.

It

may

also

be

necessary

to

recalibrate

certain

sections

of

the

instru



ment

when

transistors

or

other

components

are

replaced.

Before

recalibrating

the

instrument,

clean

it

as

previously

described.

Do

not

preset

the

internal

adjustments

as

a

preliminary

to

recalibration.

Presetting

internal

adjustments

makes

it

necessary

to

completely

recalibrate

the

instrument.

The

following

portion

of

this

manual

presents

a

step-by-

step

calibration

and

verification

procedure.

The

title

of

each

numbered

step

begins

either

with

"Adjust"

or

" heck",

thereby

identifying

the

step

function

as

calibra



tion

or

verification.

The

steps

are

identified

in

this

manner

because

any

or

all

groups

of

numbered

" hecks"

can

be

skipped

without

disrupting

the

continuity

of

the

procedure.

However,

all

adjustments

must

be

completed

in

the

order

given

and

none

should

be

skipped.

Remember

that

proper

overall

operation

is

ensured

only

when

all

steps

in

the

pro



cedure

have

been

completed

and

all

adjustments

have

been

made

as

accurately

as

possible.

NOTE

The

performance

standards

described

in

this

sec



tion

of

the

manual

are

provided

strictly

as

guides

to

calibration

of

the

Type

114

and

should

not

be

construed

as

advertised

performance

specifica



tions.

However,

if

the

Type

114

performs

within

the

guide

tolerances

given

in

the

calibration

pro



cedure,

it

will

also

perform

as

listed

in

the

har



acteristics

section

of

this

manual.

Equipmen

Required.

(See

Fig.

4-1.)

1.

Oscilloscope,

Tektronix

Type

547/1

Al

or

equivalent.

2.

Time

mark

generator,

Tektronix

Type

180A

or

equiv



alent.

3.

Volt-Ohm-Milliammeter,

20,000

Ω

per

volt,

Simpson

Model

260

or

equivalent.

4.

Three

50

Ω

coax

cables

with

BN

connectors

(Tek



tronix

Part

No.

012-057).

5.

50

Ω

BN

termination

(Tektronix

Part

No.

011-049).

6.

Variable

line

voltage

source

such

as

a

variable

auto



transformer.

4-3

Main enance

and

Calibra ion

—

Type

114

Fig.

4-2.

Ini ial

con rol

se ings

for

calibra ion.

Preliminary

Procedure

(no

power

applied)

1.

heck

the

Type

114

front-p

a

nel

controls

for

smooth

mechanical

operation,

proper

indexing,

and

knob

spacing.

orrect

all

defects

found.

2.

Remove

the

Type

114

from

its

cabinet

and

check

for

loose

hardware.

3.

heck

to

see

that

the

proper

fuse

is

installed

(0.3a

slo-blo

for

115-volt

operation,

0.15a

slo-blo

for

230-

volt

operation).

4.

Set

the

Type

114

front-panel

controls

as

shown

in

Fig.

4

2.

a.

PERIOD

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

1

µS

VARIABLE

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

AL

b.

WIDTH

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

100 n

S

VARIABLE

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

AL

c.

AMPLITUDE

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

3

to

10

V,

+

polarity

VARIABLE

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

fully

clockwise

d.

POWER

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

off

e.

TRIGGER

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

LEADING

EDGE

5.

Using

the

VOM,

check

the

resistances

between

chassis

ground

and

the

points

indicated

in

Table

4-1

(see

Fig.

4-3).

TABLE

4-1

ircuit

heck

Points

Approximate

Resistance

T281

Primary

Terminals

1

thru

4

infinity

+

25-volt

supply

Outer

shell

of

298

1.5

K

+

35-volt

supply

298

+

terminal

2

K

Checks

and

Adjus men s

NOTE

ontrol

settings

and

test

conditions

for

each

step

are

the

same

as

for

the

preceding

step

unless

otherwise

noted.

1.

Adjus

+

25-vol

supply

9

a.

Set

all

controls

as

shown

in

Fig.

4-2

b.

Install

the

50

Ω

termination

(T

e

ktronix

Part

No

011-049)

on

the

Type

1A1

hannel

1

input.

onnect

a

50

Ω

coax

cable

between

the

Type

1

4

OUTPUT

connector

and

the

termination.

c.

onnect

the

Type

114

power

cord

to

a

variable

line

voltage

source

and

set

the

input

voltage

to

the

Type

114

at

115

volts.

d.

Turn

on

the

equipment

and

allow

a

5

minute

warm

up

before

proceeding

e.

Slowly

rotate

the

WIDTH

VARIABLE

control

clock



wise

until

the

WIDTH

>

PERIOD

light

is

lit.

Rotate

the

WIDTH

—

VARIABLE

control

counterclockwise

to

the

point

where

the

WIDTH

>

PERIOD

light

just

extinguishes.

f.

onnect

the

VOM

negative

lead

to

chassis

ground.

onnect

the

positive

lead

to

the

outside

shell

of

298

(see

Fig.

4-4).

g.

Adjust

R290

(-f-25

VOLTS)

until

the

meter

reads

-f-25

volts

±

0.5

volt.

4-4

Main enance

and

Calibra ion

—

Type

114

1

µ

sec

period

adjus

C115F

R125

PERIOD

CAL

T281

Primary

connec ions

WIDTH

CAL

R180

100

nsec

wid h

adjus

C195F

+25

-VOLT

SUPPLY

+35-

VOLT

SUPPLY

+25 V

OLTS

ADJUST

R290

Fig.

4-3,

Type

114

chassis,

bo om

view.

2.

Check

+35-vol

unregula ed

supply

a.

hange

the

VOM

positive

lead

to

the

positive

terminal

of

298.

b.

heck

that

the

meter

reads

4-33

volts

4

2

volts.

Fig.

4-4.

+

25

vol

supply

adjus men .

3.

Check

vol age

across

D209

a.

hange

the

VOM

positive

lead

to

the

junction

of

D208,

R2

0

9

and

D209.

b.

heck

that

the

meter

reads

+

3

volts

±½

volt

from

the

j

unction

to

chassis

ground.

4.

Check

+

25-vol

supply

regula ion

a.

hange

the

VOM

positive

lead

to

the

outside

shell

of

298.

hock

that

the

meter

reads

+2

5

volts

±

0.5

v.

b.

Using

the

variable

line

voltage

source,

vary

the

line

volt

age

from

94.5

to

137.5

volts.

c.

heck

that

the

VOM

reading

does

not

change

more

than

0.5

v

while

the

line

voltage

is

varied

over

the

range

specified.

d.

Return

the

variable

line

voltage

source

to

115

volts.

5.

Check

+

25-vol

supply

for

ripple

a.

Remove

the

VOM

leads.

Remove

the

50

Ω

termination

from

the

Type

1A1

input

but

leave

it

connected

to

the

coax

cable.

b.

onnect

a

1

X

probe

to

the

Type

1A1

hannel

1

input.

c.

Set

the

test

oscilloscope

for

line

triggering.

Using

the

1

X

probe,

check

that

the

ripple

on

the

outside

shell

of

298

does

not

exceed

10

millivolts.

heck

only

for

60-

or

120-

cycle

ripple;

disregard

the

various

transients

noted.

d.

Set

the

variable

line

voltage

for

94

.

5

volts

and

again

check

that

the

ripple

does

not

exceed

10

millivolts.

e.

Return

the

variable

line

voltage

source

to

115

volts

and

remove

the

1

X

probe

from

298

and

from

the

Type

1A1

hannel

1

input.

4-5

Main enance

and

Calibra ion

—

Type

114

Fig.

4-5,

Con rol

se ngs

for

PERIOD

CAL

adjus men

.

6.

Adjus

PERIOD

CAL

con rol

R125

a.

Set

the

Type

114

WIDTH

—

VARIABLE

control

to

AL

Turn

the

WIDTH

control

to

1

µ

S

and

the

PERIOD

control

to

100

µ (see

Fig

4-5).

b.

Reconnect

the

Type

114

OUTPUT

to

the

Type

1A1

hannel

1

input

through

the

50

Ω

coax

and

the

50

Ω

termination.

c.

onnect

a

50

Ω

coax

cable

from

the

Type

180A

MARK



ER

OUT

connector

to

the

Type

1A1

hannel

2

input.

Set

the

Type

180A

for

100

microsecond

markers.

d.

Set

the

Type

1

A1

hannel

2

VOLTS/ M

switch

to

2

Turn

the

MODE

switch

Io

H

2.

Pull

out

the

hannel

2

PULL

TO

INVERT

switch.

e.

Set

the

Type

547

HORIZONTAL

DISPLAY

switch

to

B

Set

the

TIME/ M

(B)

switch

to

.1

mSE .

Set

the

TRIGGER

ING-SOUR E

switch

to

INT-NORM,

the

SLOPE

switch

to

—

,

and

the

MODE

switch

to

TRIG.

Adjust

the

TRIGGERING

LEVEL

control

for

a

stable

display

of

the

100

microsecond

markers

from

the

Type

1

80A.

f.

h

a

nge

the

Type

1A1

MODE

switch

to

ALT

and

the

hannel

1

VOLTS/ M

switch

to

5.

Using

the

Type

1

A1

POSITION

controls,

position

the

display

so

that

the

peaks

of

the

pulses

from

the

Type

114

are

vertically

displaced

about

1

mm

below

the

peaks

of

the

inverted

pulses

from

the

Type

1

80A

on

the

other

trace.

g.

Adjust

the

PERIOD

AL

control

R125

(se

e

Fig.

4-6

)

so

that

the

corresponding

pulses

in

the

two

traces

are

aligned

horizontally

to

within

½

%

(

see

Fig.

4-7).

Fig

4-6

.

Loca ion

of

PERIOD

CAL

con rol

R125.

Fig.

4-7.

Cr

display

showing

correc

adjus men

of

PERIOD

CAL

con rol.

4-6

Tektronix 114 User manual

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