Tektronix 555/22A, 555/21A Instruction Manual

INSTRUCTION

IVIANUAL

Serial

Number

__

___

_

Tektronix,

S.W. Millikan

070-403

Inc.

Way e P.

0.

Box

500

•

Beaverton,

Oregon

97005

•

Phone

644-0161 •

Cables:

Tektronix

464

ktronix

;;·;

§ll!lif'VJ~a

is

geared

all requestS for repairs

pad

should

ix

Field

Ofti

. This procedure

possible service.. Please inc

-illililrnrn•nt Type

p,'t_-.:,·

t:•ioJUtJSTs for

repair

parts

and

replacement-part

directly

or.

and

to

the

be

directed to

Representative

Witl

as.s

Serial number with

or service.

and

price

field., there-

and

replace-

the

in

_ure you

·

Tekyour

the

ii

T.

0.

33Al-1.3-152-ll

18 SeptEmber 1968

I

This

ITO

replaces

1.

PURPOSE~

authorizing

for

CONTRACTOR--ClMMERCIAL TITLE---

DATE--ADDITIONAL

2.

FILE

3.

SUPPL~ENTARY

commercial

NUMBER--- TJpe 555/2ll/22A

Instructions

Hot

dated.

IDENTIFICATION:

LOCATION.

publication

IDENTIFYING

ITO 33Al-1.3-152-ll, dated 1

This

technical

official

Tektronix

with

order

is

use a commercial

Parts

Breakdown

The

above

INFORMATION.

is

listed

The

information contained

supplemented

TECHNICAL

July'

issued

for

publication

..

- Oscilloscope

commercial

as

follows

ORDER 1968, and

the

purpo'e

identified

publication

in

for

official

the

cODRercialaanual.

of

identifying

as

follows'

is

filed

the

above

in

listed

use.

and

Marma1

Chaage

Reference Page

PUBLISHED This

NOTICE:

in

this

UNDER

technical

Reproduction

publication

...

Modification

1-1,

Table

AUTHORITY

order

issued

for

is

not

Insert,

1-1:

OF

THE

by

SAAMA

nonmilitary

Type

Delete

tor !actor

Delete Delete

the

'l';ype

0.005 the the

Type H plug-in.

SOCRETARY

(SANST)

use

permitted without

555,

Mod

101D,

risetime

lAl

to

of

plug-in

0.05

passband "de

riset:ime

OF

THE

cf

the

or 1123

AIR

information

specific

Copyright

11

14.5

over

v/c:ra.

to

FORCE

approval

1966

nsec" and add "16 nsec

the

calibrated

24

•c"

and add •de

nsec" and add

or

illustrations

of

the

issuing

defiection

"24

nsec"

11

to

23

ac."

tor

contained service.

AF,

Nunna &

Hhnler,

Inc

.. , C1nc1nnat1,

Ob1o4oo, 11-68

"LIBRARIAN: CHECK FOLD-OUT PAGE FILING SEQUENCE"

iv

SECTION J

CHARACTERISTICS

Type

555/21A/22A

The following Type

555

with

Type

characteristics

Oscilloscope

21 A and

GENERAL

The Type 555 Oscilloscope laboratory-type time measurements

Two

complete mit completely Either

of

sweep

of nels utilize to

select the

required

instrument providing

in

horizontal

independent

the

two

either

separate

for your

time-base

or

both

plug-in preamplifier units, allowing you

bandpass,

application.

PLUG-IN

TYPE

Wide-Band

High-Gain 0.05

TYPE

CA

Dual-

Trace

DC

TYPE

1A1

Wide-Band

Dual-Trace

TYPE

Gain

High-

DC

Differential

TYPE

low-level

AC

Differential

TYPE

Wide-Band

DC

Differential

TYPE

Wide-Band

High-Gain

TYPE

Fast-Rise 0.05 v

DC

TYPE

Fast-Rise

High-Gain 0.05 v

TYPE

Four

Trace

DC

•Data

on

special-purpose

the

of

risetime,

TYPE B 5

D

E

G

H

K

L 5

M

NOTE

are

for

the

Tektronix

(5/N's

Type

22A

7000

Time

and

Base

units.

INFORMATION

is a wide-range

de

and

vertical deflection systems peroperation

plug-in units

the

beams

accurate

to

30

Me frequency

of

the

. The

type

DEFLECTION

mv/cm

0.05

0.005

0.05

1

mv/cm

50

11-v/cm

0.05

0.005

mv/cm

0.02

vertical plug-Ins given

can

two

of input

Vertical .

v/cm

to

v/cm

Characteristics

CALIBRATED

to

0.05

to

to 20

to

0.05 v

20 v / em

to

50

to

v/cm

to

/em

to

to 2 v/cm

/em

to

vertical chan-

and

20

/em

10

20 v/ cm

20 v

10

above)

dual-beam

voltage

range.

two

beams.

control the

sensitivity

FACTOR

v/cm

mv/cm

20

v/cm

/em

v/cm

at

and

TABLE

the

end

Special circuit;

of

an

accurate,

tion of

one

.

05

microseconds to 50 seconds after

gering

pulse. This feature permits you to portion of the measurements the

delayed

oscilloscope screen.

Characteristics for both vertical channels of the oscillo-

scope

are

marily on the vertical plug -

See

Table

when using various plug-in units.

1-1

with

Specific

PASSBAND

2 cps to 12

de to 20

de to 24

de to

de

to 2

0.06 cps to 60

de to 20

de to 15

de to 30

3 cps

de

to

de to 20

of

me

23

me

to 33

me

to

24

me

30

me

this section.

incorporated

continuously-variable

of the sweeps. The

delayed

and

detailed

and

the

undelayed

VERTICAL

identical. The

1-1 for the vertical characteristics

Plug-In Units*

RISETIME

30 nsec

18 nsec

15 nsec

16 nsec

11

0.18

kc

6

11-sec

18 nsec

24 nsec

12 nsec 20 pf

15 nsec

12 nsec

18 nsec

in

the system provide selection

delay

sweep

may

application

sweep,

thereby

observation of the signal.

DEFLECTION

actual

in

units used with the Type 555.

nsec

11-sec

providing precise time

sweeps

are

SYSTEM

specifications

INPUT

CAPACITANCE

47

pf

20 pf

15 pf

47

pf

50 pf

47

pf

47

pf

20 pf

47

pf

in

be

expand

presented

the presenta -

delayed

of

from

of a trig-

a selected

Both

on the

depend

the system

pri-

®!

1-1

Characteristics-

Type

555/21A/22A

HORIZONTAL

Sweep

calibrated steps. control of sweep rates between the calibrated steps, tends slow sweep

%1

1

Rates

From

0.1 microsecond to 5 seconds

Accuracy of calibrated sweep rates

with magnifier off.

An

range

DEFLECTION

uncalibrated control provides variable

to

about

12 seconds per centimeter.

SYSTEM

per

centimeter

and

is

within 3% (typically

in

24

ex-

Magnifiers

Provide horizontal meter portion of the unmagnified crt display when the internal time

second 5% with magnifiers on.

base

Extend the fastest sweep rate of either beam to 0.

per

centimeter. Sweep rates

5X

magnification

generators provide the horizontal deflection.

of

the center 2-centi-

ore

accurate to within

02

micro-

External Horizontal Inputs

Rear-panel connectors permit application of external horizontal signals.

(3

db

approxi

down)

at

Deflection Foetor-Continuously variable from mately 0.2 volts per centimeter to approximately 20 volts per centimeter .

Passband-De

maximum gain.

Input Impedance - Approximately 1 megohm resistance

with

47

pf parallel capacitance with the

switch set

to approximately 350

at

EXT

. A

TTEN. X1.

kc

HORIZ. DISPlAY

Triggering

15/N

11000-upl

Internal- Signals producing a

of vertical deflection (

meters of deflection (+

External- Signals with minimum

(+

AC

to 30

me

(The

the

VERNIER overall signals larger than + 10.1 volts, but the lEVEl control

triggering level.)

15/N

7000-109991

Internal- Signals producing a minimum

of

vertical deflection, up

tion up to 30

External-Signals

up

to

10

(The volts, but the lEVEl control volts. The

Delayed

Sweep

ly

variable.

Incremental

1 0.00 positions of the single setting

Overall Accuracy- Within Time Jitter- less

Signal

and + DC)

.

triggering lEVEl control has

control has a

range

+ 10.1 volts. The instrument

will

not

me.

me,

or

instrument will trigger on signals

VERNIER

Requirements

+

AC

AC)

up to 30

up to 1

be

completely effective

with minimum

0.5 volts up

control

kc,

range

to

5 me,

to

is

operates

only) up to 1

30

effective

Sweep

Delay-0

.1 microsecond

Accuracy-Within

of

DElAYED

the TIME/CM switch.

3%

than 1 part

mm1mum

of

or

of

me.

to

0.2%, between TRIGGER

of

in

20,000.

of 0.2 centimeter

me.

0.6

range

of

1 centimeter

over a + 1-volt

50 seconds, continuous-

the indicated value.

kc,

0.5 volt

+ 1 volt, making the

0.2 volts peak-to-peak

over a range

peak

volt(+ AC

of + 10 volts

will

and

in

determining the

of

0.2 centimeters

greater

the

control, on

or

2 centi-

to

peak

only) up

and

trigger on

VERNIER

of

deflec-

than 10

of

+ 10

range

1.00

and

any

.)

Sweep

matic baseline,

matic baseline, single sweep, sweeps once for each 'A' delayed trigger, tr

igger.

repetition rates other sweep modes must be used.

Modes

Type

21 A in

Type 22A

Automatic baseline mode operates only on signals with

Time Base A compartment- Normal, auto-

and

single sweep.

in

Time Bose B compartment- Normal,

and

triggerable once for each 'A'

above

20

cps. Below

20

cps one of the

delayed

auto

Triggering Signal Sources

Upper beam or lower beam vertical amplifiers, external signals or power line signals; upper beam or lower beam plug-in units when using multi-trace vertical plug single-channel trigger pickoff.

Trigger Slope

Positive

and

Coupling

(+)

or negative (- ) slope, oc- or de-coupled.

in units with

1-2

CATHODE

RAY

TUBE

Type

T5550-2-1 (internal graticule). *

-

Phosphor

Type

P2

other types

normally supplied; types

available

on special

order

Accelerating Potential

1 0,000 volts.

Useable

6 by 10 centimeters. The 6-centimeter vertical dimension

consists of

common to both beams.

Trace

Traces

per 1 0 major horizontal divisions, when the traces

tered vertically

• Crt

SIN

Viewing

4 centimeters for

Alignment

are

type

is

's

7000-8999

parallel to

and

there

T5550-2

.

Area

each

is

no input signal.

(external

other

graticule)

(crt)

P1,

P7

and

P11

.

beam

with 2 centimeters

within 0.1 major division

for instruments with

optional;

are

cen-

@

Internal Unblanking

Intensity-type, de-

coupled.

External Intensity Modulation (Z-axis)

Coupling-Input

through

low external

will

rear-panel

Input Time Constant- Typically

Amplitude-Typ

Input

produce

signals ac-

connectors.

impedance

normal intensity modulation .

coupled

about

.

ically a 20-volt peak-to-peak signal

to crt control grids

10 milliseconds with

Characteristics-

Line

Fuses (located on the front panel

unit)

ore 7

amp

slow-blowing for the slow-blowing for the amp

slow-blowing for the

ing fo r the

DC

Supplies for 234-volt operation .

Line Frequency

50 cps to 60 cps.

Power Consumption

Maximum of

consumption.

about

1050

Type

555/21A/22A

of

the

AC

Heater$ Supplies for 117-volt AC

Heaters

watts

and 3 amp

including plug-in power

power

and 5 amp

operat

slow-blow-

supply

ion; 4

Multi

channels.

Trace Chopped Blanking

Crt circuit permits vertical plug-in units with multi-

blanking to tum off

the

display

while switching

between

Internal Graticule

Markings--6 divisions; 2-millimeter markings (minor divisions) on cal centerline zontal centerlines 2 centimeters from the the graticule.

Illumination-Variable

vertical

and

on

and

the

10

horizontal 1-centimeter (major)

upper

beam

edge

lighting.

AMPLITUDE CALl

and

BRA

lower

top

TOR

and

Output Waveform

Square-wave

Output

0.2 millivolts to 100 volts

signal

Voltage

at

approximately

peak-to-peak

1,000 cps.

in

18 steps.

Accuracy

Peak-to-peak

with

load

amplitude

impedance

above

within

1 kilohm.

3%

of

indi

cated

trace input

the

verti-

beam

hori-

bottom of

voltage

OTHER

Output Signals

Calibrotor- 1 kilocycle (approx .)

tudes from 0.2 millivolts to 100 volts .

Delayed approximately the

'

A'

of

'

A'

peak-to-peak, with a pulse duration

'A'

bose

'8' +Gate

peak-to-peak, with a pulse duration

sweep

'B' base

'A' Sawtooth- Time bose

150 volts

'B' Sawtooth-Time

150 volts

Trigger

5 volts

delay

period. Repetition rote of pulse

time

bose

+

Gate-Positive-going

sweep

and

generator.

generator

a repetition rote

- Positive-going signal

and

a repetition rote

.

in

ampl itude.

in

amplitude.

CHARACTERISTICS

Available

Pulse-Differentiated

in

amplitude

generator

.

bose

signal

'A'

'B'

square

, occurring

approximately

equal

to

app

equal

to

sweep

wave, at

positive-going pulses

is

the

to the duration of

that

of

roximately 25 volts

to the duration of

that

of the '

sawtooth waveform,

at

same

the '

the

25 volts

A'

ampli-

end

as

that

time

B' time

Ventilation

Separate the event of overheating, the self-resetting thermal relay interrupts instrument

forced filtered air systems for the two units.

power

.

of

In

INSTRUMENT POWER

Internal Power Supplies

Electronically

power line voltages from 105 volts to 125 volts when wired

for 117-volt

wired for 234-volt operation.

Line

Voltage

The line

cated

on

unit.

Changes

operation

indicated on

changes

Wiring and

fans

regulated

operation

voltage

a metal

can

on

design-center voltages the

are

all shown on

; from 210 volts to 250 volts when

for which

tag

on

the

be

made

Decoupling Network schematic

for the

power

circuits for

the

rear

in

the

transformers, s

the

diagram

stable

instrument is wired

panel

of

the

internal wiring to permit

of

117 or 234 volts,

.

operation

power

aturable

is

indi-

supply

diagram

reactor

on

as

Construction

Aluminum-alloy ·chassis dized front panels; blue vinyl-finished cabinets panels. Side

and

bottom panels

and

cabinets. Photo-etched ano-

separately

Dimension!!

Indi

cator

Unit- 13 inches wide; 20 inches high; 24 inches

ight without vert ical plug-in units: 68 pounds .

deep. Weight

Unit-13

inches wide; 10 inches high; 17

: 45 pounds.

Accessories

in

extension (013-013)

OX

BNC

to binding post

power

cable

Attenuation

(012-032)

adapt

ers (1 03-033)

.

deep. We

Power Supply inches

Standard

1- Time bose plug4- Attenuotor probes, 1 l- Inter-unit 2-

(01

0-127)

and

removable.

rear

1

/

1-3

2

Characteristics-

Type

555/21

A/22A

1-Test 1-Polarized 1-3-conductor 1-3 2-lnstruction

SPECIAL-PURPOSE

Type

The Type N Sampling Unit Oscilloscope permits fractional the input signal

of the signal

the input signal lent time nanosecond imately 600 factor with less

volt ond

Type

The Type 0 Plug-In Unit

amplifier

tion, differentiation, function linear amplification.

scope channels simultaneously, such

Input from 10 kilohms to 1 megohm, from 1 0 impedances amplitude pedance

Type

The test signal

ideally 107 ardization of a Tektronix plug -

is

240 tive able time

Type

The Type Q Plug-

oscilloscope such gages strain unit. The unit

'for green

groticule;

lead

(012-031}

light filter (378-545}*

power

cord

(161-01

to 2-wire

adapter manuals

(1

03-013}

(070-403}

VERTICAL

N

observation

nanosecond

base

dynamic

per

centimeter to

and

. Characteristics

risetime,

me;

range;

(1

are

is

10 millivolts

than

0·9 second} risetimes.

taken,

slightly farther

reconstructed on a relatively long

each

corresponding

2 millivolts of system noise; ± 120-milli-

equivalent

per

10

nanoseconds

0

capable

the

passband

can

impedances

picofarads

is

± 50 volts

is

approximately

of

When

of

be

used

as can

to 1 microfarad. Selection

from

an

is a dual

performing the

generation,

used with

each

channel

in

series to

double

be

selected

identical

and

30

ohms.

P

Type

P Plug-In Unit

of

known

compensated

Square-Wave

of

the main -unit vertical amplifier transient

step

functions

polarity

. Step function

between 0 and

is

approximately 4 nanoseconds.

generates

waveform,

Type K Unit driven with a Tektronix Type

Generator

in

per

. The Type P permits the

type

oscilloscope. Pulse repetition

second, with

amplitude

3 major

Q

In

Unit permits

as

and

gages

instruments

plastic

polarized

other

the Type 555 to

transducers. Excitation

and

transducers

provides

in

(378-514).

serial

filter

high

number

Green

is

for

gain,

± 5 milliamps,

0}

PLUG-IN

when

used

with the Type 555

of

repetitive signals with

sample

of

sweep

integration.

simulating the

graticule

are

ronge

filter

internal

on a different cycle

along

the

Type

to a

passband

centimeter

rates

per

centimeter.

channel

operations

and

the

Type 555 Oscillo-

is

de

to 25

perform

from 5 resistance

and 6 capacitance

range

of

a fast rise

either

positive

is

continuously

divisions. Pulse rise-

any

Textronix plug-in

be

operated

provided

low noise,

voltages

7000-8999, is for

graticule

UNITS

Samples

waveform,

N include: 0.6

input deflection

from 1

linear

me.

two

of

values.

and

step

output

by the plug-in

and

use

with

crt.

and

equiva-

of

approx-

nanosec-

operational

of

integra-

and

non-

The

two

operations

values, values,

feedback

Output

output im-

-function of

stand

response

rate

or

nega-

adjust

type

with strain

for the

extremely

light

filter

external

of

an

low drift. Frequency de

to 6 kc; sensitivity 10,000 microstrain tinuously

risetime

is

calibrated

variable

is

per

between

TypeR

The Type R Plug-In Unit

pulse

generator characteristics method. When scope,

delay

be

displayed factors meter. A directly nally

and scope 50 millivolts

between

range

to

derived

Pulse risetime

minimum

is

about

which

of

junction transistors

the

Type R is

time, risetime,

simultaneously. from 0.5 milliamp

pushbutton

the

input

waveforms.

of

the

displayed

12

nanoseconds.

to

10

steps

. Repetition

volts

the

TypeS

The

Type conductor junction Performance

dicted

tics. Since an

element can observing uring the resistance, components

The

steps

in

six

is 9 picofarads,

per

centimeter

Type

The

scope

of

operation: ferential input comparator. With age

em. Maximum resolution

As a passband do

not

volts/ em

As a differential input common-mode tion factor, 40,000 to 1. Maximum input signal

/7

volt

is

As a

three ± 10 volts,

S Plug-In Unit

diode

capacitance,

by

analyzing

be

used

the junction

Type

from 1 to 20 milliamps,

steps

parameters,

of a diode

it

is

essentially a means

while

passing

for

other

.

S offers

from 0

to

and

calibrated.

Z

Type

Z Plug-In Unit

voltage

range

nsec,

comparison

measurements.

(1}

as a conventional

preamplifier,

of

± 100 volts,

conventional

of

de

overscan

calibrated

to

the

to

25 v/ cm

signal level ± 1

and

offers a

or

-1

and

zero

sensitivity

13 me with

differential

voltage

response

approximately

is

switch

of

Type

and

the

characteristics

capacitance

calibrated

2 milliamps.

deflection

preamplifier,

screen. The deflection

in

volt f 5 nsec.

to + 100 volts.

of

the

in

10

steps

major

graticule

steps

.

is a combined

used

to

measure

used

storage

Calibrated

to

connects

the

oscilloscope

R Unit

risetime with

in 8 calibrated

the

in a particular

recovery

constant

applications

the

of

9 fixed,

preamplifier,

ranges: zero

is

Pulse

rate

is

designed

such

stored

and

for plotting current

forward

and

reverse

factors

extends

It

can

or

(3}

as a calibrated

of

50

mv

effective

the

Type

the

calibrated

00

common-mode

comparator,

Type

60

microseconds. Strain

from

division

by

in

the

time,

100 milliamps

a front-

less

the

amplitudes

is

120 pulses

to

as

charge

"turn-on"

as

of

or

inductance

currents

Diode

ore

the

be

used

preamplifier,

/ em

scale

Z Unit

the

Type

the

volts

rate

Q Plug-In Unit

10

microstrain

and

is

con-

power

supply

the

high-frequency

the

pulse-response

Type

555

and

falltime

vertical

panel

for

observing

than 5 nanoseconds

Type

555

steps

and

test

certain

junction

at

the

circuit

can

voltage

through well. For transistors,

in

currents

shunt

capacitance

0.05

and

accuracy

in

three

and

insertion volt-

range

is

Z Unit offers a

555 for

factors steps

Type Z

at

minimum deflec-

rejection

of

change

the

to ± 1 volt,

and

Oscillo-

may deflection per

centi-

terminal

exter-

Oscillo-

range

from

variable

per

second.

semi-

resistance

junction.

be

pre

characteris-

across

it, the unit

example,

or

meas-

of

circuit

five fixed

calibrated

0.5 volts

of

oscillo-

modes

(2}

as

a dif-

differential

is

± 2000

0.005% .

signals

that

ore

0.05

.

accepts

ratio

is

+ 1

Type Z has

zero

is

to

,

-

a

of

to

1-4

®

SECTION 2

GENERAL INFORMATION

The Type 555

is

adaptable

of

the potentialities

use familiar with the function ous controls. information the controls, the use of

the

sweep,

Oscilloscope

to a great

This

section

required

and

for

of

operation

Horizontal Sweep

The

two

plug-

in

'time deflection (sweeping) Either

beam

both

beams

The

Upper

are

used

beams.

In

most

used

in two positions base automatic the triggering circuit .

TION switch permit use sweep

The settings switches. the

trigger identical rates Uncalibrated

be

varied

switches,

per

centimeter when

Beam

to

applications,

the AUTO

units .

sweep

modes

sweep

of

the

In

sweep

ranging

continuously

and

can

select the time

provide

In

of

rates

turn, the

holdoff

from

VARIABLE

can

of

be

deflected

be

swept

and

Lower Beam HORIZ.

BASELINE

normal

addition,

of

the

Other

operation.

of

the

appropriate

sweep

period

characteristics. There

.1

p.seconds to 5

extend

the

Sweep Triggering

The oscilloscope

of

the

crt

screen while

of

tion random, of traced

the

drift across the screen .

appear cha

To

must In is

the

or

the

input signal,

out

woveshope

In

most cases

stationary racteristics produce a stationary

be

time-

the Type 555 Oscilloscope,

display

beam

from left to right

an

input

beam. If

at

voltage

the

some

rate

a different horizontal position

would either

it

is

desirable

on

of

the

wav

to

displayed

OPERATING

is

number

of

operation,

the

between

the

a versatile instrument which

of

the

and

of

input

base

the two

the

trace

of

two

. The

controls permit

the

switch

is

sweeps

not

eform

display, the

applications.

instrument, you should

operation

the

manual

including the functions

cables

and

of

the

delayed

units

produce

cathode-ray

by

simultaneously

repetition

waveform

either

base

units

to

SWEEP FUNCTION switches

or

NORMAL positions. These

triggered

AUTO

when

positions

the single

beams

TIME/CM

rate

sweep

formed

signal

be

for a repetitive

oscilloscope screen so

the

operation

BASELINE

no

signal

of

sweep

are

and

determines

two

time-base

are

seconds

the

steps

rate

is

in

the 5 SEC

by

the repetitive

across

produces

were

allowed

to

waveform

indistinguishable

con

be

start

rote

starting

by

To

of

each

provides

probes,

sweep

the

tube

time

base

by

the

DISPLAY

drive

the

provides

is

the

SWEEP FUNC-

and

determined

HORIZ.

the

24

calibrated

per

the

sweep

of

the

to

about

position.

the

oscilloscope

vertical

the

repetition

each

waveform

examined

of

each

of

the

input signal.

time

of

using the input sig-

make

become

of

the

tri

ggering

feature.

horizontal

same

switches

separate

of

the

applied

delayed

DISPLAY

duration

units

centimeter.

rates

TIME

12

seconds

to

occur

would

time

or

that

in

the

vari-

basic

beams

unit,

unit.

time

by

have

sweep

/ CM

sweep

deflec

would

detail. sweep

sweep

INSTRUCTIONS

nal

or

full

of

or

are

an

to

the

of

to

at

rate

be

and

to

the

another 2-1

Figure nal, the triggering signal, for a typical sine-wave superimposed on a holdoff waveform so the crt

retrace

again

before the trigger signal

sweep.

.

Fig. 2-1 .

sweep

operation.

The two units

air

can

by

fans

at

the

rear proper the fans

-

becomes

power

the this occurs , check units. A constant

ation

of

onc

e with the instructions given

of

this manual.

Transformer Conver

This instrument

indicated

Power Supply Unit.

60 cycles. The transfor me r

time-related

shows the time-relationship

to the left

of

the screen

Input

and

display

------------+---

' ' I

Triggering

1

I I

I

Horizontal

rvv1

Ladder

diagram

circulate freely

in

the

separate ur,

of

the units.

operation. Never

operating. If too

high, a thermal cuto ut w

until

the instrument. Keep the

on the

showing

INSTALLATION

of

the osci

about

Side

the inteonol

the temper

the

air

filt

temp

erature

sion

is

wired

tog

adjacent

Li

ne freq

signal to

and

Crt

llos

its

operate the oscilloscop e without

ature has

ers

lo

cc.

start

(trigger) the

between

the

horizontal

. The triggering signal

and

is

allowed

Signal

I

''--;,....

Holdoff

. I

Sweep

I I

Display

waveform

cope

should

them . Ventilation

that

draw

panels

should

temperature

ill

returned to normal.

and

the

is

important

air

filters

in the

operate

to the

u<=

ncy must

;1

be convented for

sweep

be

ready

to

___

Signal

1

rv

sequence

be

placed

air

in

through filters

be

open

and

clearance

for

accurate oper

clean

Maintenance

with the line

power

be

between

sweep

the input sig-

voltage

beam

con

to

sweep

start

a new

_

in

triggered

so

that

is

provided

in

place

for

in

either un!t disconnect

around the

in

accord

section

voltage

plug on the

50

and

operation

.

is

If

-

·

®

2-1

Operating

Instructions-

Type

555/21A/22A

on nominal line

ing connections on the saturable

on the Decoupling

Fuse

data

fuses

or

The Type 555 Oscilloscope letter-series the two vertical deflection systems,

Time-Base Units to

The use

change

to meet a wide ticular plug-in units to requirements plug-in units, flection factor

Plug-

in servicing supplied with the Type 555 allows operated the oscilloscope. For normal are

left

screws

located

The side

access

to

voltages

reactor

. Rewire

is

given

converting

SELECTION

and

1-series plug-in units

of

plug-in units

the vertical characteristics

range

of

your applications.

yo~

and

type

time-

and

calibration

with either time

in

the Type 555,

at

panels

of the oscilloscope must

the retaining screws (see

of 117 volts

two

transformers, the fans

according

Network

to

generate

must consider

number base

the

schematic

in

the

electrical Parts list for

another

OF

PLUG-IN UNITS

the horizontal

at

the vertical inputs permits you

of

application

be

used must

and

units

are

. The plug -

base

operation,

and

rear

of

line

is

designed

the

type

used primarily for

unit

are the time-

or

234 volts, by

to

the

diagrams

diagram

voltage

as the input

and

of

requirements. The

be

selected to satisfy the

In

selecting the vertical

bandpass

of

in

the

partially

held

Fig

. 2-2).

.

Types

the

inputs

extension

instrument

the Time Base Units

in

base

be

replacing

to use Tektronix

stages

21 A and

sweep

oscilloscope to

, risetime, de-

required

accessory

extended

place

by

compartments

removed

chang

and

the

shown

for

22A

voltages

par

.

ease

to

from

thumb-

to

gain

of

be

22A must

delayed

The Type 555

of

the

Operating

damage

not plies to instrument will plies

are

.

-

All the Type 555 scope oscilloscope (s complex section,

FUNCTIONS

AMPLITUDE CALIBRATOR Switch

.

CAL Connector

SCALE Control

DELA

YEO TRIGGER FROM 'A' TIME (1

-1 0

DELAYED

TRIG

. OUT

Connector

be used

sweep

feature

Oscilloscope

plug-

in

units installed

the instrument with a

the

oscilloscope,

go

out

of

regulation

not

regulating

FRONT

controls

and

functions

in

the discussions

.

AND

and

connectors

are

located

its plug-

ee

Fig. 2-3). Some

are

OF

Sets square-wave OUT 18 peak-to-peak.

OUT

ILLUM.

BASE

MULTIPLIER)

Provides 1 for checking systems probes. Amplitude controlled sw

Controls intensity lamps. Rotate clockwise ination; counterclockwise ination. The markings for measurements

Sets time

A pulse.

CM control.) livered and layed

Provides a from Time Base A for nal device .

setting

and control. (See Fig

for Time Base B

of

the

instrument.

should

or

but

operate

due

correctly unless

in

not

connected

plug-in

may

cause

to

insufficient

order

be

used

by

unit missing will

the

REAR-PANEL CONTROLS

required

on

units

treated

of

the

and

in

the

in

CONTROLS

Indicator Unit

the

amplitude

signal

connector

steps

from .2 millivolts

kc

square-wave

gain

and

for adjusting

itch.

sweep

by

lamps

accurate

.

duration

and

(Operates

Delayed

to

DELA

to

Time Base B Trigger circuit for de-

sweep

operation.

delayed

Delay

of

Time Base A TIME/CM switch

DELAYED

for front on

of

greater

various

AND

. Amplitude

AMPLITUDE

output

with Time Base A

YEO

TRIGGER (1-10

2-1

the

panels

the

rear

the controls which

detail

modes

CONNECTORS

of

the 1 kc

available

is

of

output

the

vertical deflection

compensation

of

output

graticule

to

edge-light

time

decrease

time

between

of

Delayed

trigger

TRIG. OUT

trigger

triggering

is

determined

0).

of

increase

to

use

the

without extensions.

power

loading.

power

operation

the

panel

later

of

at

adjustable

to

CALIBRATOR

illumination

the

and

triggering

pulse

output

MULTIPLIER)

all

sup

The

sup

oscillo-

of

the

have

in

this

operation.

(approx.) the

CAL

100

volts,

primarily

signal

illum-

graticule

voltage

Trigger

TIME

is de-

connector

pulse

an

exter-

by

-

of

in

of

is

of

/

Fig.

2-2

screws.

Base A plugin Type 22A

. Location

Normally,

the Time Base B

may

2-2

of

the

a Type

in

21

compartment,

compartment

be used

lime-base

A Time-Base Unit

for Time Base A; however, a Type

and

vertical plug-in locking

is

used

and

a Type 22A Time-Base Unit . Either a Type

in

the

21 A or

Time

a

INTENSITY Control

Upper Beam and Lower Beam

Adjusts

compensate caused ing crease crease

the

brightness

for

by

changing

rates

. Rotate control clockwise

brightness; counterclockwise

brightness.

of

changes

the

sweep

display

in

brightness

or

trigger

to

to de-

to

-

in-

Operating

Instructions-

Type

555/21A/22A

CAUTION: Excessive intensity nently

damage screen. Use the

beam

the

level

the

crt

spot

FOCUS Control

HORIZ. Switch

HORIZ. POSITION

Control

Beam-Position Neons

CRT Connector

(rear

CRT

Switch internal multi-trace

EXT. INPUT

EXT GAIN

Trigger INPUT Connector

DISPLAY

CATHODE

panel)

CATHODE Selects intensity

HORIZ. Permits

Connector

. HORIZ.

Control

Adjusts focus for mimimum The internal ASTIG. control for tive

beam

beam. See

adjustment

source

Selects age

from

external

either

an magnification (X. rate

and

ternal

horizontal

Controls

trace;

positions display controls of coupling

Indicate or

Small

direction the light during

sweep

will

vertically.

Permits intensity creases intensity. 1 0-volt signal appreciable connector external

externally CATHODE CATHODE position in

nal for Front-panel HORIZ. be

Controls produced Horizontal varia

em with HORIZ.

TEN. X1;

at

Time

Permits from

onto

both

the

beam

the

spot,

whether

arrows

screen

rate

be

unlit

application

intensity; positive-going

signal.

chopped

application

horizontal

in

one

ble

from

EXT

ATIEN .

Base A and

application

an

external

the

INTENSITY control

brightness

that

causes a halo

or

trace.

of

trace

also

the

Calibration

of

the of

horizontal

either

time-

horizontal

unmagnified

2)

X1

or

X1 0 attenuation

input signal.

horizontal

any

the

coarse

position, using a

between

electrical position

beside

of

the

beam

. Both

the

is

slow;

if

modulation.

intensity

grounded

applied

connector.

mode.

of

the

amount

by

externally

deflection

approximately

from 2

to

X10.

Time Base B

source

can

phosphors

turned

crt

spot

width

affects

ASTIG. control.

base

input. Also selects

(X1)

of

the

position portion

crt

screen and

the

two

on

or

off

the

lamps

from

horizontal

sweep

both

the

display

of

external

Negative-going

modulation.

except

modulation

chopped

signals

leave

except

of

external

deflection

DISPLAY

EXT.

A TIEN positions.

of

horizontal deflection

factor

DISPLAY

20

volts/

of

that

of

down

to form

or

trace

or

spot

the

focus

Procedure

deflection

unit

or

display

time-base

of

crt

of a magnified

. Single knob

fine

adjustment

"backlash"

controls.

of

the

crt

indicate

the

lamps

of

the

dot

vertical

is

signal for

change

when

signal from

switching through switch

when

voltage

of

switch must

applied

is

continuously

0.2 to 2

switch

em with switch

triggering

is

time-

permathe

crt

to

keep

below

around

. Adjust

diameter

respec-

of

the

for

volt-

from

the

or

SX

sweep

of

an

ex-

spot

the

trace

screen

the

center

may

if

the

lamps

centered

in-

decreases

produces

leave

applying

CRT

in

CRT

operating

sig-

crt

beam.

voltage

volts/

EXT. AT-

signal

of

or

.

Switch

.

Control SWEEP

Switch

.

Trigger SOURCE Switch

Trigger COUPLING Switch

Trigger SLOPE

Trigger Control

Trigger VERNIER

FUNCTION

TIME/CM Switch

VARIABLE Control

UNCALIBRATED Neon

LEVEL

the

to switch

Selects from

Selects input

nal

Selects falling form for

Selects causes Operates

Selects range small

Selects

basic

(The last Type operation.

Sets

using the

from

meter Varies

steps

sweep

meter Sweep VARIABLE BRATED ments.

lights in

input signal. Set

to

EXT.

the

source

one

of

six sources :

UPPER signal, Vertical Amplifier

UPPER BEAM off positions in

LINE cuit (50 to

EXT. trigger ternal

NORMAL; AUTO

SINGLE SWEEP; SWEEPS

TRIG.;

TRIGGERABLE DLY'D

BEAM

from

beam;

BEAM

PLUG-IN, from the

in

the

apply

units with

signal, from

trigger

either

triggering

or

external

either

(-)

portion

triggering

trigger

over

triggering

for fine

triggering

mode

of

modes:

BASELINE;

ONCE

TRIG

two

22A.)

See

sweep

rote

that

time-base

sweep

CALIBRATED

voltage.

.1

p.seconds

.

sweep

of

TIME

rote

to

with switch

rate

is

control.

positi

when

the

vertical plug-in unit. (These

60

the

.

on

trigger

to

use

external

of

the

triggering signal

or

LOWER

the

trigger

of

PLUG-IN

only to multi-trace plug-

trigger

pickoff);

the

cps);

signal

INPUT

oc-

signal

source.

rising (

circuit a ± 1 0-volt

adjustment

signals. sweep

positions

text

of

rate / CM switch, about

not

for making time measure-

VARIABLE

position.

regulated

applied

conector

or

de-coupling whether

+)

of

the

triggering

the

sweep

waveform

to

level

over

operation

FOR

EACH

ONCE

FOR

are

for specific

the

beam

unit for

Sweep

to 5 seconds

continuously

12

seconds

in

the 5 SEC

calibrated

leave

control in

SOURCE

trigger.

BEAM

pickoff

the

respective

or

LOWER

trigger

through ex-

.

from inter-

portion

(see Fig. 2-6).

level

start a sweep.

range.

a ± 1-volt

or

for use on

from five

"A'

EACH

only on the

mode

(or beams)

generation

rates

per

between

and

extends

per

position.

when using

Control

input

in

pick-

oc

of

or wove

that

DLY

range

centi-

CALI-

is

the

Cir-

the

-

'D

'A'

of

not

2-3

Operating

Instructions-

Type

555/21A/22A

2-4

Fig.

2-3.

Front-

and

rear-panel

controls

and

connectors.

®

PUSH

TO

RESET

Button triggerable condition. READY

STABILITY Adjustment

SAWTOOTH

Connector

+GATE

Connector

POWER Switch

Power Indicator lamp

Output

front panel of the Type 555 Oscilloscope sytsem. These are: an Amplitude Calibrator square wave; a Delayed Trigger pulse; a Sawtooth waveform from each time base. Typical wave-

forms trace vertical plug channel signal output for triggering oscilloscopes from only one single-channel signal to the triggering circuits through ternal wiring.

ing or driving external devices this application, the time-base unit running sweep.

Neon

ON

Signals

Several low-impedance signal outputs

+Gate

are

input signal.

Use

of

the

Calibrated

The

edge with 10 horizontal 2 millimeter subdivisions marked on the vertical centerline and

the two horizontal centerlines. The deflection factors of

the crt beams the marks provide a calibrated scale for making time voltage measurements.

To

protect the graticule shield and viewing plastic scratch shield. For viewing under bright ambient light conditions, use the light filter to provide better traceto-screen contrast. When using the light filter, however, be

careful not to set the beam intensity so high that

the crt phosphor.

crt (instrument

or

plastic light filter

filter

and

Resets Single Sweep lockout circuit to a

lights when Single Sweep lockout circuit is

in

triggerable condition; light

is

when sweep of the crt.

Sets input level of Sweep

stable

triggering.

Provides output voltage waveform, 150 volts peak-to-peak, capable devices. Time Base B sawtooth waveform includes layed mode.

Provides output of sweep gating waveform,

20 volts peak-to-peak. Time Base B waveform contains delay time when

ating

in

Power

Applies line power transformers. A time-delay relay allows the tube cathodes to warm up before de power

is

Indicates that the low-voltage circuit.

waveform from each time-base unit;

illustrated

+Gate

in

Fig.

-i

n units provide

In

the Type 555, these units

and

held off after single sweep

of

horiz.:>ntal

of driving

delay

delayed

Supply

applied

2-4.

Sawtooth waveforms for trigger-

or

triggering external

time when operating

mode.

Unit

to

low-voltage power

to circuits.

ac

line voltage

are

In

addition, some multi-

an

amplified single-

is

illustrated

is

usually set for a free-

goes

Gate

circuit for

deflection

is

applied to

available

apply

in

Fig.

+Gate

2-8.

Graticule

-lighted internal graticule and

6 vertical 1-centimeter divisions

are

calibrated to these graticule marks.

bonded

are

provided with the instrument.

for photographing the display, use the clear

plastic faceplate of the internal

S/N's

9000-up), always use a scratch

in

front

is

accurately marked

of

the crt. The shield

For

it

will

normal

in

oper

at

and

Thus

burn

out

de-

the

a

the

in-

In

and

Operating

Instructions-

Type

555/21A/22A

I I

7 Volts:.l

-

I I

t-

__.,.

Selected

I

voltage

amplitude

-

T

-

25

Volts

..1.

T

150

Volts

.i

Fig.

2-4.

Output

For instruments with external graticules (S/N's 7000-8999), the color of the graticule illumination may be changed from white to red, or vice versa, by rotating the graticule

180°.

Vertical Controls

The vertical plugfront-panel vertical positioning that beam. Refer plug-

in

units for operation of the vertical controls.

CONNECTING

Input signals on the crt screen two vertical plug-

Use

of

Coaxial

In

general, coaxial cables should signal source to the vertical input. The use of coaxial cables nearly eliminates pickup from stroy electromagnetic fields, and

also eliminates radiation from the connecting cables by grounding the outside conductors. use

an

and

unshielded input lead

if

its

frequency

r-1Del~y

t--

'-I

tije

Frequency - 1

/ v

v

v.

.....

d.

waveforms

in

unit for

to

the instruction manuals

TO

t~at

are

to be displayed

are

applied

in

units.

Cables

is

low.

.l

...

~

I

kc

-

.I

Sweep'4

~

-

I

tir

/

/ v

Sweep

rmi

I

available

at

each

and

THE

to the input connectors on the

if

the signal amplitude

When

an

r-

~

1--

1---1

v

.

...

It-!-

I

the

front

panel.

beam contains all the

deflection controls for

of

SIGNAL

as

vertical deflection

be

used to connect the

It

is

sometimes possible to

unshielded

DELAYED TRIGGER

AMPLITUDE

CALIBRATOR

+

GATE

r-

SAWTOOTH

the particular

SOURCE

is

lead

is

high

used,

2-5

Operating

Instructions-

Type

555/21A/22A

connect the chassis

signal sources impedances. Unterminated connections result tions within the waveforms. The input

nate

of the plug-in unit will provide sufficient termination for sig-

nal reflections . However, erably end

oscilloscope on the signal source must resistance 1 megohm which a negligible

capacitance

pacitance tive versely affect both the

tion

reduce

Use

attenuator

played permits observation of signals

limits amplitudes, however, must able

properly adjusted

manual with the vertical plug-in unit accompanying

by connecting the

and on the crt screen. The compensating

justed to provide minimum distortion

another

In

high-frequency work

the signal source,

different from

of the

When

connecting

loading

of

the signal source. Attenuator

capacitive

of

In

addition

waveform by

of

value

Before a

observing several cycles of

corner of the

lead

of

the signal source.

and

connecting

cables

coaxial

that

cable

may

an

at

the input

adequately

value

. However,

of the vertical plug-

of the input

at

high frequencies

and

Probes

to reducing the

probe

also

the

the oscilloscope

of the

probe

is with the plug-in unit. according

used,

to the

the

probe. In

probe

square-wave

between

and

also

input signal,

of

displayed

resistive

decreases

being used.

the oscilloscope chassis

it

is

usually necessary

cables

in

cause

distortion of the

cable

a termination

if

the source

of the connecting

need

the vertical plug-in unit

cable

attenuation

and

be

it

must

procedure

cable

will often serve to termi-

impedance

to

be

terminated.

the

loading

limits low-frequency

at

high frequencies, the input

in

and

becomes

loading

load

beyond

plug-

limited

Compensation

general,

to

signal (see

significant.

may

be

waveform

probes

to

on the signal source,

the

amplitude

factor

the normal

in

combination. Signal

to

the maximum allow-

be

compensated

given

and

this adjustment

one

of the vertical inputs

the

calibrator

capacitor

of

the Fig

and

to

their characteristic

placed

be

the distributed ca-

very small

of the

terminate

in

signal reflec-

displayed

at

the input

is

cable,

considered. The

sufficient

and

can

in

top

. 2-5).

consid-

the source

effect

of

is

usually

loading

Capaci-

to

the

opera

be

used

values

of

the

probe

. This

amplitude

to

operate

of the

probe

the instruction

the instructions

is

done

waveform

is

then ad-

and

leading

the

ad-

dis-

an

Internal Triggering

Either time-base unit Upper Amplifier, the

plug-

in source applied

base

unit. Selection

SOURCE switch.

It

is

of

the UPPER these

positions, a

from the

to

the Trigger circuit.

off or internally

is

same

.

triggering.

is

If

a multi-

is

used,

LOWER

triggered

If a Type to Units, ing base loscope cal

If a Type be Units, provide channel the IN nected.

Sources

can

be

Beam Vertical Amplifier,

unit, or can

usually most convenient

input signals by setting the SOURCE switch

BEAM

point

Upper

the

be

to the

external

or

selected

trace set

BEAM

to

the Trigger circuit. in each

555

be

used

the

wire

plug

and

unit)

should

will

plug-in

555

used

with

the

oscilloscope

internal

triggering

UPPER

BEAM

positions

Order

Beam plug-

power

used for triggering with the

trigger

of

the triggering signal

LOWER

sample

Vertical Amplifier circuit

plug-in unit with single-channel

the SOURCE switch

PLUG-IN

this manner,

time, relative

with

Serial

with

Type

between

the

ceramic

be

not

be

compatible

units with

with Type

connection

signal.

PLUG-IN

of

the

modification

triggered

line signal.

INPUT connector

to

BEAM. With of the vertical signal

to

apply

When

each

NOTE

Number

21

and

19

strip

removed. Otherwise

single-channel

Serial

Number

21A

and

will

need of

Without

and

SOURCE

kit

internally from the

the

lower

Beam Vertical

in

unit,

the

In

addition,

trigger

the switch

to

UPPER

the single-channel signal

a multi-

trace

to

the

7000

Type

on

the

(inside

with

below

Type

to

the

multi-trace

the

LOWER

switches

number

lower

trigger

on

is

made

internally from

is

and

trigger

BEAM

trace

is

triggered

channel used for

or

above

22

Time-Base

interconnect-

each

the

multi-trace

pickoff.

7000

22A

Time-

be

modified

modification,

BEAM

are

040-328.

an

external

the time-

with the

to

in

one

picked

applied

PLUG-IN

display

time-

oscil-

verti-

is

Base

single-

PLUG-.

discon-

Beam

signal

one

either

of

off

to

pick-

at

the

is

to

TRIGGERING

For most

gered

being of a suitable triggering signal controls.

applications

by some signal

observed

on the crt. This section discusses the selection

-

------

the oscilloscope

that

is

Incorrect

2-6

THE

SWEEP

sweep

must

be

trig-

time-related to the input signal

and

the

use of the triggering

._

.

~

r

Fig. 2-5.

\...

r !

Probe

Triggering from the the vertical input signal This

type

of satisfactory for triggering . Set the SOURCE switch for

stable

waveform.

\...

I...

,

(

Incorrect Correct

compensation

waveforms.

operation

triggering on the constant-

\.,

J,.

~

power

line

is

time-

is

used when the input signal

....

1-

is

- - -

-

sometimes useful when

to

the line frequency.

line-frequency

-

....

~

is

not

to

LINE

-

Operating .Instructions-

Type

555/21A/22A

External Triggering Sources

If

a triggering signal than those of the input signal, the external trigger introduced through a jumper lead, a coax connected

switch on the time-base unit

External triggering device under test. The triggering signal can any observed anywhere triggering controls. Phasethe signals

when the triggers

particularly useful with multi-trace plug-in units.

Triggering from

of

time-jitter measurements when

stable

to

the trigger

convenient point

can

be

than the displayed input signal.

is

required with characteristics other

it

can

be

applied

INPUT

connector. The signal may

INPUT

connector. Set the

to

EXT.

is

convenient for signal-tracing

in

the circuit, then signals can

in

the circuit without readjusting the

and

determined directly from the crt display

are

taken from a single source.

an

external source increases the accuracy

time-relationships between

the

trigger source

by means of

cable,

be

or

taken from

Triggering Controls

The trigger

from either the rising (

of

the tions it the desired display, although some waveforms can gered

on either slope. Generally, waveform will provide the most selection of the triggering slope will nature of the triggering signal. desired.

SLOPE

switch provides selection of triggering

+ slope)

triggering waveform (see

is

necessary

Sweep

on

to

trigger on the proper slope

triggen

+

slope

SLOPE

or

falling (-slope) portion

Fig. 2-6).

the

stable

and

In

many applica-

to

steepest portion of the

triggering, but final

depend

the type

f7

on both the

of

~+

a probe

SOURCE

in

This

is

more

provide be

trig-

display

I\ I\

be

is

The trigger gering signal AC

position

cations, since triggering

position of the waveform on the crt screen. The of the switch should ticular de level, signals.

a

The trigger the triggering waveform where triggering occurs (see

2-6).

These the display. The volt range,

To

trigger

rotate the

is

form triggering level can then Turning counterclockwise causes triggering tive point on the waveform, triggering are

approximately centered when the display triggered. The the trigger level when small

are

nals

The following procedure strument beam

operation

Connect the two main units of the instrument together with the inter-unit power line. With time-base

stalled following positions:

FOCUS

INTENSITY

HORIZ.

COUPliNG

is

ac

of

the

or

LEVEL

are

the last controls to

LEVEL

has

ten times the effect of the

the

LEVEL

presented on the crt screen. Fine adjustment of the

used.

control until a stable display of the wave-

at

a more positive point. Normally these controls

VERNIER

FIRST-

in

operation

is

illustrated.

cable

in

the lndicatqr Unit, set front-panel controls to the

DISPLAY

switch determines whether the trig-

or

de-coupled

COUPliNG

is

be

used

if

triggering

and

VERNIER

control, which

sweep, center the

be

control

TIME

to

and

connect the Power Supply Unit to the

Upper

Centered Counterclockwise TIME

to

the Trigger circuit. The

switch

is

then not affected

if

triggering

is

done on very low frequency

controls

be

operates

VERNIER

made

with the

and

turning clockwise causes

is

or

display the input signals. Dual-

convenient for adjusting

high-frequency triggering sig-

OPERA

is

and

liON

suggested for setting the

vertical plug-in units in-

Beam

BASE A Xl

used for most appli-

by

the vertical

DC

position

is

desired

at

a par-

set

the level on

control.

is

properly

-+-

Fig.

1

and

in-

set when triggering

over a

VERNIER

control

VERNIER at

a more nega -

0-

Fig.

LEVEL

!(5\

Waveforms with set

2-6

. Effects

LEVEL

in

the

Sweep

on

of

or

VERNIER

obtained

+ region

triggers

- slope

the

control

trigger

SLOPE,

LEVEL

!(5\

Waveforms

with

LEVEL

set in

the

LEVEL

and

VERNIER

or

VERNIER

obtained

- region

control

controls.

FOCUS INTENSITY HORIZ. DISPLAY

Time

TIME/CM

VARIABLE SWEEP

FUNCTION LEVEL SLOPE

COUPLING

Lower Beam

Centered Counterclockwise

TIME

BASE B Xl

Base A and

Set

input waveform;

with .5

CALIBRATED AUTO

Clockwise Set to

negative slope, AC

frequency triggering.

Time

to

display 2 or 3 cycles of the

mSEC.

BASELINE

+ for positive slope; - for

for most signals;

Base

B

if

unknown, start

as

desired.

DC

for low-

2-7

Operating

Time SOURCE

Time Base B SOURCE

lnstrudions-

Base A

Type

UPPER

LOWER

555/21A/22A

BEAM

Vertical Plug-In Units

Deflection Factor

Input Coupling

Connect input signals

both beams as described previously. If ing signal connector

Turn panel of the Power Supply Unit the units to warm up. A time-delay relay Unit delays the operation

45 seconds after the

allows the tubes sufficient time ating voltages

for

the de power

Using the beam-position neons free-running traces on the crt screen, then adjust the SITY

Rotate the the triggering signal · NIER Position the traces with the they start FOCUS controls for the sharpest possible focus.

Use

The HORIZ.

selection of five times magnification on that sweep. switch from the 2

em then (see

expanded,

appropriate

The sweep indicated by the TIME/CM switch. The true centimeter

the reading of the TIME/CM switch by 0.2, by five.

If sweep magnification the this section.

Use

The two beams The Upper Beam

Upper Beam display; the Lower Beam HORIZ. POSITION

is

desired, connect

and

set the

on the instrument with the POWER switch on the front

are

an

instant, the normal 45-second

is

restored.

control for a trace

LEVEL

control may

at

the left

of

SX

Magnification

beam,

using either time-base

To

magnify the display, move the HORIZ.

of the display with the switch

expanded

Fig.

delayed

of

to cover the entire 1 0

2-7). Any 2-cm portion of the original display, now

can

HORIZ

rate

of

the magnified

sweep magnification

Horiz. Position Controls

Set to produce 2 tion on crt screen.

AC

for most signals;

mining de levels.

to

the vertical input connectors

it

appropriate

power

applied.

controls to trigger

is

be

adjusted for the most stable triggering.

edge

DISPLAY

X1

position to the

be

positioned on the crt screen with the

. POSITION control.

of the magnified display

have HORIZ.

to the external trigger

and

of

the instrument for approximately

switch

to

If the

of

adequate

small or of high frequency, the

HORIZ.

of the graticule,

switch

of

sweep

greater

independent horizontal positioning.

POSITION control positions

or 3 em

an

SOURCE switch to

allow a few minutes for

in

is

turned on.

heat

before the

ac

power

delay

as

a guide, position the

intensity.

the

POSITION controls

either

of

the signal displayed

generator

X.2

position. The center

on

the

em

is

found by multiplying

than

5X

mode

described later

of

deflec-

DC

for deter-

external trigger-

INPUT

EXT

the Power Supply

This

delay

de

is

will occur before

two displays.

and

beam

X1

of

the crt screen

is

five times

sweep

or

is

oper-

interrupted

INTEN

adjust

provides

to

drive the

DISPLAY

position

time

by dividing

required, use

of

VER-

so

the

that

per

the

control positions the Lower Beam display. Clockwise rota-

tion

of

either control causes the to move rotation moves the PLAY POSITION control portion

coarse

backlash coupling position the control slightly to the desired final position. The fine adjustment control only

operates

For

.

POSITION control clockwise for the the then turn the control slightly counterclockwise for fine

justment

to

the right

switch

of

the

Each HORIZ. POSITION front-panel knob

and

fine adjustment

trace

in

example, to move the

trace

HORIZ.

the backlash

position

of

the

DISPLAY

on

the crt screen,

trace

is

set for

expanded

past

trace

5X

provides sufficient

display.

between horizontally, turn the HORIZ. POSITION

where

is

about 2 mm

position.

X.2

•

xo

-

If

HORIZ.

X.

2

Xo M •

Fig.

2-7. Operation

is

DISPLAY

Unmagnified

.,

......

of

the

SX

OPERATING

The Type 555 Oscilloscope provides many modes

operation,

applications. The normal triggered mode, is

started

input signal,

of

both time-base units

Sweep modes.

in

Triggered

Set

AUTO

display with the

previously. (AUTO is a sweep low-frequency automatic triggering

Tektronix oscilloscopes.) For triggering rates

making the instrument

by a signal

is

that

the most common

Sweep

the

SWEEP

BASELINE

FUNCTION switch

for normal triggered

LEVEL

and

BASELINE

mode with automatic baseline, rather

trace

of

the particular

to

the left. magnification

of

the positioning by means

the controls inside the unit. To

you

of

the

trace

-

1-

and

When

(X.2),

range

want

it,

then move

coarse

to

adjustment control.

the

right, turn the HORIZ.

coarse

past

the desired location,

- -

-

,

I--

swHp

magnification.

MODES

adaptable

in

is

time-related to the

sweep

is

the same

VERNIER

in

the Type

mode.

except

to

either NORMAL

operation

controls

21 A and

mode

counterclockwise

the HORIZ.

to view

operates

adjustment until

1-

-

1-1-1-

beam

the HORIZ.

DIS-

any

both

of

it

back

-

~:..

-

of

to

which the

for the

found

above

sweep

a variety

sweep

displayed

Operation

Delayed

. Trigger the

as

described Type 22A

than

in

many

20

cps,

a

ad-

of

or

the

2-8

Operating

Instructions-

Type

555/21A/22A

triggering LINE.. baselme rates

~UNCTION

mterm1ttent free-running

With

swe:p

rece1ved. After the

is

the

same

in

either

In

addition,

trace

below

AUTO

when

BASELINE

no triggers

20 cps, use NORMAL position

switch, since AUTO

baseline

the

SWEEP FUNCTION switch

is

held off until a

beam

trigger

has

are

swept for the next triggering pulse, then pulse

reaches

With

~ontrol

I~

the T1me-Base trigger pulse triggered to

be

triggered). However,

1

/20th

the Time-Base

pulse

is

Free

Run

To

free run the on the time-base plug-in unit the

LEVEL

wise.

In

the

sweep control, signals causing intermittent free run mended range. This will the

trigger free run the set the SOURCE switch triggers (e.g.

A free-running tioning the crt can

be

the

swit~h

set

for tngge_red

absence

of

Generator

is

received within 1

sweep

of

of a second,

Generator

received.

control

AUTO

BASELINE,

will free run

however

when

that

random

the control

the

also

amplitude

sweep

EXT.).

beam

used

to

establish a reference

selected

set

triggering level.

to

AUTO

BASELINE

operation,

tnggers.

When a trigger

stops free running. Then,

/20th

the

trace

will occur (if the

if

the

sweep,

no trigger pulse arrives within

auto

baseline circuit will

to

free run until

set

the SWEEP FUNCTION switch

to

either

fully clockwise

with no triggering signal

in

nearly

triggering will

is

set

at

operation

LEVEL

control

allow

is

less than 10 volts. If you desire

in

the

to

sweep

is

be

a signal

presence of a

some position receiving no input

convenient for locating

while no input signal

de measurements.

With a free-running tors

can

Sawtooth

initiate the input signal by using the

output test. The response the

sweep

repetition present a switch tion

stable

and

VARIABLE

rate. (This

waveform with the

To

display

beam

crt put +Gate mode To

display more than form, set base

unit for driving the crt

one

with the time-base unit

or

of

operation

the

HORIZ.

second time-base unit for

To

display both the from the external device, vertical INPUT

sweep,

one

waveform

may

rate

of

control

be

observed

other

time-base unit.)

to

trigger

will then

the

on

to

time-base

the

produce

cycle of the response

Sawtooth waveform.

with Time Base B

one

cycle

DISPLAY

switch

beam

triggered

output

waveform

apply

and

the response signal

NORMAL

or

AUTO provides a free-running applied.

BASELINE

in

this frequency

of

the

and

begins

the

sweep

For triggering

of

will

at

NORMAL the

proper

amplitu,de

retraced,

when the

and

the triggering

is

free running

is

received, the

the SWEEP

produce

if

of a second

a normal

swe:p

again

another

AUTO

BASELINE

or

fully counterclock-

any

position of the

occur

the

. Therefore

set

display

on stray noise

zero

triggering level,

at

either

to

free run

large

it

is

end

input signal,

and

is

voltage

of

applied. It

level for making

the

time-base

+Gate

or

drive a device

be

synchronized with

generator

crt. Set the TIME/CM

the desired repeti-

by monitoring the

waveform

that

is

generating

Fig

. 2-8 illustrates this

and

or

a portion of the

to

, drive the

the Lower Beam.

the

second

. Set the controls

operation.

and

to

the

the response

signal

other

the

output

BASE-

range

it

waits

trigger

another

is

ready

cause

trigger

and

turn

applied,

LEVEL

recom-

of when

posi-

also

genera-

under

and

will

output

the out-

wave-

time-

of

the

to

one

INPUT.

an

.

its

to

or

is

Fig.

2-8.

Using

th"

+GATE

or

drive

The

external

two

equipm

beams

ously. Similarly,

under

vice

two

the

Delayed

section of

test

beams

sweep

the

manual.

..

nt.

will then display

two

may

and

multi-trace plug-in units.

pulse

SAWTOOTH

sw

..

ep

is

usually

or more response signals from the de-

be

displayed

generation

Single Sweep

Single

sweep

mode

is graphing tive

To

tion, first

a portion

or

that

varies

display a triggered

set

up

FUNCTION switch

then move the switch to SINGLE SWEEP. Press

TO

RESET

button immediately, the button will light, indicating the time-base circuit be

triggered sweep be

held off until the and

Single

ex

cept

. Then, when o trigger arrives, the crt

once, the

released

READY

.

sweep

s wili not occur without a triggering signal

by turning the triggering level. signal, the SOURCE switch

the

LEVEL

sweep

pressed released

In

PUSH

when

control

circuit

and a sweep

.

addition

TO

RESET

the

instrument

is

to

its usual function

button may also

used primarily for viewing

of

an

input

waveform

in

amplitude

the

triggering controls with the

set

to

and

release it.

READY

or

single

sweep

NORMAL

lamp inside the

lamp will turn off,

PUSH

TO

RESET

LEVEL

To

produce

adjusted armed

of the

contrd through the normal

single

may

be set to

for line triggering. Then the single

as

the

PUSH

trace

be

is

operating

waveform

free

the

waveforms simultane-

together

is

discussed

to

running

.

through use of

later

that

is

not repeti -

shape.

of the crt presenta-

or

AUTO

BASELINE,

the

If

no trigger

PUSH

is

TO

is

beam

and

the

is

again

without

LINE

RESET

as

the button

sweep

position

button

sweeps

TO

occurs

in

single-sweep mode, the

used to cut off the

normally

in

one

of the trig-

trigger

in

or

photo

SWEEP

PUSH

received

RESET

ready

pressed

an

input

button

sweep

or

this

-

to will will

and

is

®

2-9

Operating

gered held in, the sweep cannot Normal operation

Instructions-

or

free-run modes. Whenever the button

is

Type

555/21A/22A

be

triggered

restored when the button

and

is

pressed

will

not free run.

is

released.

and

Delayed Sweep

The Delayed Trigger pulse which occurs during

of 'A' Time-Base

Generator This

Delayed Trigger from Time Base A can be used to hold

as

Generator

well

as

to

is

applied to the 'B' Time-Base

the

DELA

YEO

TRIG.

off the triggering or sweep of Time Base B for a certain selected period after the

The delay time

is

continuously variable from .05 p.sec to 50

seconds. When the Time Base B

is

in

the

SWEEPS

ONCE

Time

FOR

Base A sweep has started.

SWEEP

EACH

'A'

DLY'D the Time Base B sweep occurs immediately the delay period.

MODE

When

1:

SWEEPS

~~.·

----------------~~--------------------~~~~

~

I

'A' Trigger

pulse

the

ONCE

SWEEP

FOR

FUNCTION switch

EACH

each

sweep

OUT connector.

FUNCTION switch

TRIG

position,

at

the

end

is

'A'

DLY'D

TRIG

'A'

starts

of

in

Sweep

Dly'd

the

TRIGGERABLE tion, the Time Base B sweep delay

period,

and

ONCE

FOR

will sweep

EACH

is

triggerable

as

soon

'A'

as

DLY'D

at

the

a pulse

from the Time Base B Trigger circuit. These two modes

illustrated

Operation

magnification

Use of the is

a.

To nal device connect a connector to the device under test signal to the

runs

trigger

'B'

sweep

in

Fig

. 2-9.

given

in

Delayed

of the

delayed

the Applications section

Trigger

are

delayed

described

trigger

in

and

the following paragraphs.

sweep for making time measurements

of

this manual.

use the Delayed Trigger pulses for triggering

cable

from the

INPUT

of either vertical plug-in unit. Set the

DELA

and

connect the response

v-'1

delayed

YEO

TRIG

end

is

received

an

TRIG

posi-

of

the

are

sweep

exter-

. OUT

MODE 2:

'A' Trigger

Delay time

(Variable from

0.1 t<sec

f\.-JLJL.J\.:-_fL~~-

A

Sweep

presentahon

,,----------------------------------

:

'

B'

TRIGGERABLE

l

Kl

I

p~lse

t

:

lr<

I 0 1 t

1 • t<sec o sec

I

I I

I

: I

I I

1\

Sweep

presentation

ONCE

-------------~~------------------~

. Delay time

----------~~--------~~~:

.t\-JLJL.~L

A

Sweep

presentatoon

to

SO

secl

FOR

EACH

'A'

DLY'D

'A'

Dly'd

arms

'

B'

(Variable. from 1

so

1

'READY'

goes

J

LJLJL--~LL'L

-------------

-----------

I

'READY'

_______

light

may

go

on

i

I

I I

I

.J

Brightened portion l

of

waveform

__

1\. 1\.

TRIG

'A'

Sweep

runs

'

B'

trigger

L/'1

light

on

Sweep

is

triggered

I

Brightened portion

of

waveform

J

LILJL.JLJL.l

------------------------,

r

~::

v"'"l

.

'----

------,

.'U

'

/-------------------- -------------

1\.

'B'

Sweep

presentation

1\

~----------1\.

1\.

....

~

I

Fig.

2-9.

tensified portion

Comparison

2-10

of

tho

of

the

'A'

two

delayed-sweep

presentation

shows

modes.

the

part

of

In

each

case

the

'A'

the

Input

waveform

presentation

that

is

displayed

represents

in tho 'II'

tho

Input

to

presentation.

both

vertical systems Tho

in-

•

®I

H.

ORIZ. DISPlAY ?•splay one cycle JOg

source

switch for that

of

and

the

sweep mode will

The Delayed Trigger pulse

TRIG.

OU~

generator

sweep,

TRIGG~R

CM

IS

runnmg.

at

a time determined by the setting of the

1-10

swrtch

MULTIPLIER

and equals the desired (see

Fig.

2-1

0).

TIME

lASE A

TIME/CM

conn:ctor

the

at

One

1-10

delay

beam

to Time Bose A

waveform. Selection

depend

is

available

any

time the Time Bose A

output pulse

on the application.

at

will

of

the

occur for each

X1

the trigger-

DELAYED

sweep

DElAYED

dial. Set the Time Bose A TIME/

MULTIPLIER

time, from

DELAYED

1-1 0

dial so their product

0.1

p.5ec

to

135

TRIGGER

MULTIPliER

seconds

to

Operating

tion

of

the signal that follows the triggering point. There-

fore

~ith

normal !riggering

exomme any section

immediotelr

after

mode prov1des a means

by a

sel~cted

a~y

porhon

usmg the

trigg~r

by

T1me

Both

the magnified

amount following the triggering point, so that

~f

vanoble

Time Bose

Bose A can

lnstrudions-

it

is

of

the waveform that does not occur

a triggering point. The

of

delaying the start of

the waveform

Type

555/21A/22A

not possible to expand

delayed

each

can

be

expanded. Thus

Delayed Trigger from Time Bose A to

B,

any

portion

be examined

and

the unmagnified waveforms con then

of

a waveform displayed

in

detail with Time

and

sweep sweep

by

Bose

be displayed together on the crt screen. The maximum sweep

speed

of the beam driven by Time

creased,

o!

VIdes

and

the

apparent

delaying the Time Base B

up to 1

O,OOOX

Time Bose A display

magnification

apparent in

this manner.

Bose B is

sweep

. Delayed triggering pro-

not actually

is

merely the result

sweep magnification of the

in-

B.

the

Time

em

of displace-

delay

time

lase

wave

If

of

about

A

A.

it

the

(Ill

by

muhiplying

reading.

control determines the time of

Fig.

2-1

0.

sweep

rate

Since the

occurrence

X

Delay

time

is

by

the

1-10

of

the Delayed Pulse, it also positions the

calculated

1-10

MULTIPLIER

form on the crt screen when sweeping with Time Bose

Each whole number ment from the left

Time Bose A con

operated

in

free run mode, the repetition rote of the Delayed Trigger pulses will 'A' Time-Bose the TIME/CM switch.

8

p.5ec

to

50 seconds with the TIME/CM switch.)

If

Time Bose A

on

edge

be

the some

Generator

(This

is

operated

the dial represents 1

of

the screen.

either triggered

as

circuit

at

rote con

in

a triggered mode, on output

or

the repetition rote

that particular setting of

be

varied from

free run.

Delayed Trigger pulse will only occur after Time Bose A has been triggered time period. Time Bose A must complete trace before of the Delayed Pulse output when Time Bose A will

depend

and

the repetition rote

Time Base B con

cycle

of the waveform when Time Base A rote. However, the display produced by Time Bose B hove to DElAYED source

is

externally from Time Bose A

and

it

is

on both

the signal

has swept for the duration of the

its

sweep

again

triggeroble. Thus the repetition rote

the

frequency of the triggering signal

of

the Time-Bose Generator circuit.

be

used for displaying more than one

or

for viewing

an

expanded

is

set for a low repetition

delay

and

is

triggered

portion of

will

be

triggered

TRIGGER

and

1-10

will not

be

MUlTIPLIER

positionoble with the unless the triggering

derived from Time Bose A. (Trigger Time Base B

+GATE

if this positioning

re-

desired.)

b.

Delayed

Because triggering circuits

Iorge changes

gered directly from the input signal

Sweep

Magnification

are

in

the input signal, any crt display that

designed to

can

only display the

operate

is

on trigpor

Either crt beam

sweeping

it

can

be

with Time Bose

operated

B,

in

the

delayed

but usually the Upper Beam

used to display the unmagnified waveform

and

the

lower

Beam

is Bose B). beams

In

the following discussion

ore

operated

To magnify a portion

used for the magnified sweep

it

is

in

this manner.

of

the Upper Beam display:

assumed

1. Connect the some signal to both vertical nectors.

2.

Set the Time Bose B TIME/CM switch for a sweep rote

-

is

somewhat foster than that of Time Bose

3. Set the

0.50

DElAYED

and

9.50.

TRIGGER

1-10

4. Trigger the Upper Beam display with the usual manner.

5. Set the Ti SWEEPS

Position the INTENSITY displays of

me

Bose B

ONCE

lower

and

FOCUS controls

adequate

SWEEP

FOR

EACH

'A'

Beam display on the crt

of

intensity.

both beams for sharp

(Time

MUlTIPLIER

FUNCTION switch to DlY'D

Bose B triggering con-

trols hove no effect on the display.) The Upper Beam trace

should hove a brightened portion indicating the section

that

is

the 1-

magnified by the

10

MUlTIPLIER

dial

lower

Beam (see

and

note that the brightened por-

tion moves smoothly along the Upper Beam display.

any portion of the Upper Beam display (except the extreme ends) con be magnified on the

triggering

of

Time Bose B with the 1-10

dial readings indicate the number

lower

Beam by adjusting the

MULTIPLIER.

of

major groticule divisions

between the beginning of the Upper Beam display

intensified portion of the trace.

The

the set for 1 mSEC/

is

the magnification

degree

ner

is

equal to the ratio of the Upper Beam sweep rote to

lower

of

sweep

magnification presented

Beam sweep rote. For example,

em

and

is

1 00 times.

Time Bose B

is

set for

if

If some input other than the Upper Beam signal

played

by the

lower

Beam, the intensified portion indicate the time-relationship between the two sweeps, but the

lower

Beam presentation

of the Upper Beam display.

-

will

not

be

a magnified view

mode by

(Time

Base

that

the crt

INPUT

A.

between

Time

Bose A

TRIG

.

and

adjust the

Fig.

2-11

).

and

in

this man-

Time Bose A

10

fLSEC/

is

will

is

A)

(Time

con-

in

Turn

Thus

The

the

is

em,

dis-

still

®

2-11

Operating

Instructions-

Type

555/21

A/22A

/

Intensified

portion

'

fig

. 2-11. Thr.

ponded anc!

c. T

riggerable

W hen using a high

mod

e, time-jitter con sometimes be a

jitter

is

delay system. The TRIGGERABLE

DLY'D TRIG

gered

time, to eliminate time-jitter.

Set up the viously described, then set the Time Bose B T

ION TRIG. Set the Time Bose B the

input MULTIPLIER be

triggered

the

delay display the 1-10 MULTIPLIER

If

no completion be

held Bose B READY ready

to

the Time-Base

will

turn

Base

A sweep

depend

nal

as

If

separate sweep period

. Therefore the brightened display or

might

d.

Delayed +Gate

To

use a delayed

for

pulsing

for

ment Bos

e B +

for

free-run

FUNCTION

TRIG. This

form

for

row

nar

intensified

dis

played

by

portion the

lower

of

the

beam

upper

.

Magnification

magnification

due

to

jitt

er

in the signal,

mode

allows

by

any

small

delayed

switch

to

TRIGGERABLE

signal. Then turn the DELAYED TRIGGER 1-10

dial

and

at

any

interval. The

will

jump from one

triggering

of

the

off

be triggered. Then, when the

off

on the occurrence

well

might

may

not

delayed Gate

each sweep

puise car.

delay

untii a

lamp

Generator

. Thus the time between the start

and

as

on the settings

triggering

occur

appear

or

driving

or

operation

switch to

will

produce a single Time

the Time Bose B sweep to be

triggering

sweep presentation in the manner

triggering

notice

that

small

triggering

brightened

triggering

dial

is

turned.

signal

is

applied

period,

triggering

will

light

will

sweep

the start

at

any

at

+Gate

sweep

Sawtooth to the device.

of

be

of

the Time

of

signals any

time

place post the

all

.

and

Sawtooth

or

on external device, set up the instru -

operation,

and

set

SWEEPS

obta

ONCE

the

'A'

Time-

ined with Time

ratio

problem

and

port

ONCE

event

following

ONCE

FOR controls

the

magnif

point

portion

of

point

to

Time

the Lower Beam sweep

pulse

is

received. The Time

to

indicate

trigger and

the Time

the

ore

following

portion

delayed

the Time

Bose

Bose B triggering

delay

applie

d, the Time

of

delay

Sawtooth

then a

FOR

Bose B output

Bas

e Gene

~

1\'

beam

display

is

in the

delayed

. Port

of

is

due

FOR

SWEEP

EACH

ied sweep con occurring

the

to the next

Bose B at

that the sweep

signal appears,

the READY

-time controls .

the

pply

Set

Bose B SWEEP

EACH

Base

to

EACH 'A'

the

delay

FUNC-

'A'

DLY'D

to

trigger

after

Upper

Beam

lamp

of

the Time

B sweep

Base

delay

Upp

time position ,

Time

rator

time

er Beam

waveform

the Time

Bose

'A'

DLY'D

wov

. A very

B set for a

ex-

the the

trig

pre

on

the

will

will sig-

as

A

e-

sweep rote much foster than

amplitude

Monitor oscilloscope The repetition rote setting control; Time

e.

Uses

urements

from

of

the Time

the

Bose

Time

Measurements

of

the

ore

+Gate;

the Time Bose B

to

set

up

of

Bose

duty

factor

B TIME/

CM

delayed

given in the

that

of

Time

150 volts from Sawtooth).

output

waveform

the

repetition

the

output

A TIME/

is

determined

switch

mode

for

Applications

pulse

CM

and

making

rote

and

is

determined

switch

by

the setting

VARIABLE

accurate time meas-

section

External Horizontal Deflection

To deflect one ternally-derived through set the corresponding front-panel HORIZ. DISPLAY switch to one

control varies the deflection volts/em TEN

-

the switch

vides

-

comparing comparisons. The

about

signals

through intensity

the rear-panel

of

the

with

Xl

position,

Horizontal

low-frequency X-Y

350 kc, therefore

below

Time relationship

Intensity

The

two nectors on the lation

signals.

is

B

To

modulate CATHODE CRT

CATHODE switch

apply

a 10- to 50voltage going the front-panel INTENSITY control.

information shape to able the beams on the crt screen

is

signals decrease the beam intensity

voltages increase the intensity from the level set

Intensity

of

the

make time measuremen

from the

two

beams can be used to

Be

sure to

not in use.

Multi-Trace

Th

e Type 555 provides a multi-trace sync pulse from each

of

il s time-base units

verti cal

plug

of

the crt beams

voltage

EXT

. A TTEN positions. The

the HORIZ. DISPLAY switch

at

EXT

deflection

one function to another,

this frequency.

modulation

signal,

EXT

and

from

. A TTEN

with

operation

upper-limit

X-Y

of

the

horizontally

apply

HORIZ. INPUT connector

factor

about

Xl

0.

an external

of operation

X-Y

with

the external signal

EXT. HO.

from

2 to 20

voltage

of

the oscilloscope

or

the

display 10-

for

horizontal

must be

may

or

20-volt

Modulation

beams have separate

rear

panel

one

of

connector, check that the CHOPPED

modulation

to the displayed signal

waveform.

graticul

ground

the crt beams, unground the

is

in the

volt

signal to the connector. Positive-going

can be used to relate

Intensity time markers can be

ts

e marks . Identical signals

or

the

CRT

CATHODE

for

application

CRT

more precise than those

horizontally

to

correlate

CATHODE

of

CATHODE position

without

reference the

them in time.

connector when it

Operation

for

channel switching in multi -tra

-in units. The

use

of

multi-trace units

Bose A (25

with

another

duty

factor

and

of

about at

making phase

intensity modu -

and

by

VARIABLE

of

control.

this manual.

with

on ex-

RIZ.

GAIN

0.2 to 2

the

EXT.

volts/em

signal

passband

limited

be

provided

timing

pulses.

input

BLANKING

negative-

other

voltag

changing

added

obtain

applied

provid

volts

the

and

AT-

with

pro

for

to

con-

CRT

-

and

by

the

to

two

ce

es

.

-

is

e

-

2-12

®

simultaneous viewing traces resulting from played

trigger signal the or that

input signal, thus showing the time-relationships of played in

put, channel. If the time-relationships est,

on

one

multi-

waveforms.

each

trace

an

external

trace uni

in uni

is

SOURCE switch

BEAM

trace

For plug -

trigger

LOWER

the Triggering section for use of

For multi-

of

several input signals .

one

vertical input unit will

beam

and

at

the

same

sweep

rate

ts

with single-channel trigger pickoff, the

applied

will

internally

PLUG-IN,

t.

This permits triggering on only

(Be

sure

units without a single-channel tri

be

triggered

trigger

signal can

to

is

set

to

depending

to

read

on

of

the time-

UPPER

the

older

the the

be

base

BEAM

on the position of

compatibility NOTE

instruments.)

waveform from signals

used,

or

are

the triggers

All

of

be

.

unit when

PLUG-IN

one

the

gger

out that

of

inter-

the

dis-

Operating

can

be

derived

the

other

beam.

Provision switching transients Chopped a

sequence

the next, an

instant, then

CHOPPED

panel blank the crt

-

one

channel

desirable

the CHOPPED BLANKING-CRT CATHODE switch

CATHODE for normal

is

mode

of

so

that

BlANKING-CRT

of the Type 555

beam to

for

Chopped

Instructions-

from a time-

included

. During

rapid

another.

in

when

the signal the

while the multi-

the Type 555 for blanking the

operating

each

switching occurs from

signal

to

CHOPPED BLANKING. This will

Single-

mode

operation

in

one

in

the next channel. Set the

CATHODE switch on the

trace

channel

operation. Be

.

Type

555/21A/22A

single input

a multi-

channel

in

the

unit

triggering

trace

Chopped

one

is

applied

unit

in

the

mode,

channel

displayed

switching from

sure to return

is

usually

to

for

rear

CRT

to

2-13

NOTES

SECTION 3

APPLICATIONS

GENERAL

The displayed waveform on the oscilloscope crt screen normally a plot played horizontal deflection. The Type 555 Oscilloscope con for making accurate measurements for flection factors measurements

ships between input signals.

one

in

or

of

the vertical direction

more input signals by means

of

the two deflection systems. Comparison

can

also

VOLTAGE

Vertical deflection

to the

voltage

unit

at

the time of measurement. The amount of displacement

for

any

uotor (Volts/Cm) switch

ficient deflection for best resolution, set the vertical deflec-

tion factor so the display spans a

cule. Keep the

In

general, all voltage measurements way, though the techniques may vary for different types input signals. Voltage-difference measurements (including peak-to-peak) displayed waveform, be made from reference level. The instruction manuals accompanying most

vertical plugsible with the particular units. The basic methods of measure-

ment will

When measuring between points on

sure to measure consistently from either the

tom of the trace. This will avoid including the width

in

trace

at

the

given voltage

VARIABLE

can

be

any

point

in

units describe the voltage measurements pos-

also

be given briefly here.

the measurements.

INFORMATION

voltage

per unit time. Voltage

and

time

of

both voltage

be

made

of

phase

is

of

the calibrated de-

and

MEASUREMENTS

of

the

crt trace

INPUT

connector

can

be

on

the plug-in unit.

control

made

of

and

instantaneous measurements can

on

the display

is

directly proportional

of

the vertical plug-in

selected with the input aHen-

To

large

portion

in

the

CALl

BRA

are

made

the

ac

components

to

some established

any

crt display, be

top

represented

is

be

and

time-relation-

provide suf-

of

the grati-

TED

position.

in

the

same

of

or

the

of

dis-

used

time

any

bot

the

Voltage-DiHerence Measurements

The

ac terms of the peak-to-peak value difference between cases either input. to use oc-coupling to prevent the de component of the signal from deflecting the trace off the screen. quency input signals, de-coupling must measurements.

Always check the gain making voltage measurements. Set the input attenuotor to .05 calibrator signal.

To peak or between two points on the display, use the following procedure:

component

ac-or

In

certain applications, however,

volts/

em

and

make a voltage-difference measurement from peak-to-

of

any

two

de-coupling

of

check for 2

waveform may

or

points on the display.

can

be

the vertical plug-

em

of deflection with a

be

in

terms

of

used

at

it

may

be

For

be

very low fre-

used for accurate

in

measured

the vertical

a voltage-

In

many

necessary

unit before

.1

volt

as

of

in

1. With the deflection ploy.

is

Be

position.

2.

Multiply the divisions ical setting of the input ottenuat factor of any external ottenuators or attenuator probe. product a

peak

-to-peak measurement, this

J \ I

aid

of

in

centimeters between the two points on the dis-

sure the

is

the voltage difference between the two points. For

the groticule scale, measure the vertical

VARIABLE

control

of

vertica l deflection by the numer-

or

is

in

the

and

by the attenuation

the

ac

signal amplitude.

\

fJ

r\

v

1

2.1

an

deflection

of

J

'

Fig.

3-1. Voltage-difference

display.

Vertical

=

Voltage

Example: 2.1an

As

an tween two points on the display. at 1 volt/em, product of 2.1 volts, the voltage Assuming the signal

other external attenuator, multiply the 2.1 volts by 10 to

obtain

For sinusoidal waveforms, the

can

be

the use

deflection

.

X 1

example, Fig.

multiply

21

volts

as

converted to peak, rms,

of

standard conversion factors.

Instantaneous

To

measure the instantaneous

level

of chassis ground, use the for voltage-difference measurements. Before connecting the input signal, establi this, first set the timeset the vertical input coupling to reference voltage to the vertical input at should be selected on the basis of polarity the signal to be duce the signal, level. From this time Vertical Position control . Disconnect the reference voltage.

the input signal

one of the horizontal graticule lines. The graticule line

applied

it

measu,.....ent

X Deflection

volt/em X 10 = 21

3-1

shows

2.1

em

is

applied

the voltage

Voltage

and

some reference voltage such

same

general procedure

sh

a de reference level on the crt.

base

unit for a free-running trace,

. If a probe

should also be used to set up the reference

on

, make no further adjustmen

between

factor X Attenuation

volts.

2.1

em

If the input attenuator

by 1 volt/em to

at

through a

at

the source.

peak

or

of

the

INPUT

lOX

-to-peak measurement

overage

Measurements

(de)

voltage between the

DC.

Connect the desired de

and

position the trace

and

is

to

be

CALIBRATED

This

~

two

I

v

\

points

on

the

factor

deflection be-

probe, with no

values through

used to intro-

is

set

obtai

n a

connector.

as

described

To

do

and

amplitude of

ts

with the

as

3-1

Applications-

Type

555/21A/22A

I

renee

Refe

level

/

'

"

Fig.

3-2.

nal

Example: -1.7

established reference level trace. Fig measurement.

-34

reference level

ponent level

taneous

estimated by drawing on imaginary line through the ponent

the waveform

line (see Fig. 3-

Instantaneous

and

reference

Apply the signal

volts, being measured

This method may

of

the

of

level.

em X 2

. 3-2 shows.on

In

of

any

waveform

oc

component

voltage. In

the signal

and

3)

.

~

v

L

voltage

volts/em X 10

and

measure

example

the

example,

zero

volts (chassis ground) .

also

by

general,

so

that

the

line,

I I

-1.7

em

deflection

of

I-"'

~

measurement

and

the instantaneous

in a negative

be

used

estimating the

and

treating this level the

the

area

is

equal

/

....

between

= -

34

the

voltage

the selected point of the

of

on

instantaneous

to

measure the

overage

on the screen,

above

A

~

displayed

volts.

between

direction from a

overage

as

de

level con

and

1

olh

o

v

voltage

de

com-

voltage

an

instan-

oc

com-

between

below

sig-

the

be

the

calibrated VARIABLE

Either of the sweeps may

of

the HORIZ. The CM

In

1

to Time measurements with the later

To make a time measurement between two points on a waveform displayed by a single procedure

1. Using the groticule scale, measure the horizontal deflec-

tion

Be

sure the

position.

2. Multiply the divisions of horizontal deflection

numerical sett ing

is

unit time

3.

apparent time interval. If the HORIZ. actual

and

all measurements must

Time/Cm control

sweep

setting by 0.2.

addition, the Time Bose A 10,000 times

in

this section.

in

centimeters between the two points on the display.

that

between

If

the HORIZ.

time interval

DISPLAY

rote

is

.

VARIABLE

is

sweeping the beam. This product i.s

the points.

time

by

be

mode

with the

in

the CAliBRATED position.

be

magnified 5 times through use

switches for increased resolution.

then determined by multiplying the TIME/

sweep

may

be

and

measured

Time/

of

the TIME/CM switch

DISPLAY

0.2 (or divide by

is

equal

in

delayed

Cm

control

switch

DISPLAY

to

the

sweep

beam,

is

5)

apparent

magnified from

delayed

will

use

is

in

the CAliBRATED

of

set

at

X.2, multiply the

to

obtain

switch

time.

sweep

be

described

the

is

at

mode.

following

by

time-

bose

apparent

actual

X1,

the

Fig.

3-3. De-component

de

level

separates

The

calibrated

any

horizontal distance on the screen to represent a specific

of

interval displayed measured directly from convenient for measuring the input signal con with the TIME/CM switch on the time-bose unit.

Set the taining the two points tion

time. Thus the time

by

either

sweep

of

the groticule. The

measurement

waveform

TIME

sweep

rate

into

MEASUREMENTS

rates

beam

on

the

crt screen. The

so

that

of

interest

sweep

of

displayed

regions

of

the horizontal systems

lapse

between

the

oscilloscope screen con

the

part

is

spread

rates

signal.

equal

area.

any

sweep

of

the

wav

over a Iorge por-

must

be

Average

cause

two

events

be

rote most

selected

eform con -

accurately

5.3

em

HORIZ

DISPLAY

:

X

.2

Fig.

3-4

. Time

measurement

Sweep

rate X magnification

Example:

ment from the display. Assuming the TIME/CM switch to at 1 mSEC

izontal deflection

obtain

then multiplied by 0.2 to give 1.06 msec

interval. Basic Accuracy of the time measurement con checking the

5.3

Fig

. 3-4 illustrates on

and

the

apparent

If the two events

gering point on the waveform, separate

If this

magnify the waveform

the points sufficiently for

is

the

1

em X 1msec/cm X 0.2

example

the HORIZ.

of

5.3

em

time

sweep

accuracy

case,

of

use

of

interest

one

and

Sweep

rate: 1 msec/cm

from

display. Horizontal

Time.

1.

06

msec.

of

time interval measure-

DISPLAY

is

of

5.3 msec. The

the particular

of the

measure the time interval

switch

multiplied by 1 msec/cm to

is

3"/o

do

not closely follow a trig-

it

may not

delayed

apparent

as

at

all

be

sweep

accurate

at

the

be

measurement.

sweep

deflection

X.2,

the hor-

time

actual

sweep

improved by

rates.

rote.

possible to

modes to

X

be

is

time

as

3-2

Applications-

Type

555/21A/22A

described

actual time interval will

urement multiplied by the Time Base B

above,

directly from the

be

the horizontal deflection meas-

Dual-Beam Time Measurements

Time-comparison measurements can time-related events beams

are

advisable

beams. This reduces rate

Since

necessary to register

fore brator

AMPLITUDE

TIME/CM .5

Input Attenuator

Trigger the display on the positive

. two waveforms to .superimpose them

center

controls on the vertical line change the

beams

Remove the nectors played.

tween points on the two single

Accuracy racy of the particular

driven

to use the

tolerances.

the

applying

signal to both inputs

of

the graticule. Adjust the two HORIZ. POSITION

so

the rising portion

the

position

are

and

connect the

Now

beam.

of

displayed

at

the

same

the

two

beams

the

the input signals.

CALIBRATOR

at

the

of

thus registered.

time-interval measurements

either HORIZ. POSITION control

calibrator

the time measurements

sweep

by

same

overall error resulting from

are

two

left

signal from the two INPUT con-

two

beams

the two beams,

sweep

time-base unit for driving both

positioned independently

beams

with respect to time be-

To

do

and

set

.1

.05

at

the start

edge

of

time-related signals to

as

rate

used.

the

slope

described

delayed

rate.

this, connect the cali-

VOLTS

mSEC

volts/em

on

of

the

depends

sweep.

sweep

rate.

be

made

between

if

It

following controls:

and

each

other

each

trace

graticule. Do not

can

be

above

on the

both

is

generally

sweep

it

position the

at

begins

after

be

made

for a

accu

The

the

dis-

be-

play

at

the vertical centerline. Record

MULTIPLIER

6. Turn the 1-10 the brightened portion then center the point on the cord

7. Subtract the first the

by

the time interval

A variation of this method applied on the

is

then positioned with the 1-10 two points above

Precision mode separated of

the MULTIPLIER sweep of

the

accuracy

all

%

1 ticular and

If a number

different rates the various fractional correction factors. This will permit tion

-

measurements

dial (e.g. 5.14).

MULTIPLIER

at

the

the setting

setting of

to only

lower

. .

can

measurements

rate

1-10

error

sweep

Delay Stop adjustments

and

of

accurate

of

the 1-10

reading

the

Time Base A TIME/CM switch to obtain

between

one

Beam. The

and

the

of

time measurements

be

as

great

by 9

em

dial,

as

used

and

MULTIPLIER

is

within

3%

of

measurements

by

checking

rate

of

sweep

accurate

rates, check the calibration

the

DELA

sweep

time-interval determinations from the time

made

the

INPUT

and

beg

time interval

as 1 part

on

the

crt screen. However, the accuracy

depends

well

as

on the

the

accuracy

dial

is

at

all

the

used,

rates,

sweep

and

measurements

YEO

TRIGGER 1-10

and

with

the

sweep

the

setting

of

the 1-10

dial to position the start of

second point on t

lower

Beam display. Again re-

MULTIPLIER

from the second and multiply

two points.

is

obtained

the

waveform not mon itored

inning

of

the intens ified portion

MULTIPLIER

calculated

made

in

900 if the two points

on

the

linearity

accuracy

of

observations. linearity

within

0.5%.

rates; however, the over-

can

be

increased

rote

that

accuracy

sweep

MUL

table

by calibrating the Delay Start

at

make a

delay-time controls.

he

control.

with the signal

at

each

as

described

the

delayed

of

Calibrated

rate

are

of

the 1-10

the particular

to

less than

on the par-

.

to

be

made

of

the

TIPUER

percentage

rapid

display,

of the

sweep

dial

calcula-

are

at

or

Increased Accuracy Time Measurements

The

delayed

time measurements on

intensified portion of the display method,

dial.

To

display, use the following procedure:

1. Connect the signal source to both of

connectors.

2. Set up the instrument for described previously, with the Time Base B TION switch TRIG

position.

3. Trigger controls.

4. Adjust the Upper Beam intensity so

of

the

tion CM

switch

form to a small

5.

With

position the start

on the

interval to and

position the corresponding point

sweep

mode

may

be

the

Time Base A display using the

the

time interval

measure

in

the

displays with the Time Base A triggering

trace

is

to

reduce the

spot

the

DELA

Upper

of

Beam display,

be

measured. Then observe the magnified display

is

between

SWEEPS

easily visible. Set the Time Base B TIME/

the

read

two points on the Upper Beam

brightened

or

a small portion

YEO

TRIGGER

brightened

used to make

as

a time marker.

from

the

1-10

the

vertical INPUT

delayed

ONCE

at

sweep

SWEEP

FOR

EACH

the

brightened por-

portion of

of

the display.

1-10

MULTIPLIER

portion to the first point

the beginning

in

the

lower

MULTIPLIER

operation

of

accurate

In

this

FUNC-

'A'

Dl

Y'D

the

wave

dial,

the

time

Beam dis-

as

Frequency Measurements

Since

the

frequency

of

its

reciprocal quency one previously (see Fig. 3-5). Frequency ample,

be

cycle

2.1

can

if

p.sec,

be

as

determined

the

period

the

period

calculated

of

frequency

J\

.l.

"\

-

3-5.

Fig.

Example

Sweep

: f = 2_1 f.1sec

.\

I

~2·:f

I

'~

Frequency

'fl

rote: 1 p.sec/

measurement

1

em

of

any

repetitive signal

(time required for

directly from the time interval of

by

one

of

the

= 1

a recurrent waveform

equals 1 /2.1

\

1

I

'\

.\

I

J\

\

;I

em

using

the

relation:

=4.76X10'

cps=476kc

is

equal

one

cycle), the fre-

methods described

/Period.

is

measured

p.sec,

or

f\

.\.

.1

\

I

v

' I

f = -

.

to the

For ex-

4.76 me.

,.

1

~

1

T-

to

3-3

Applications-

An

alternate method display that obtained by dividing the per centimeter of screen by the sweep rate of the display

Fig. 3-6)

(see

ft

v

Type

555/21A/22A

of

determining frequency from the

is

usually easier

. Determine the frequency

1\

"

average

1\

I

1\

and

"

I I

\

\j

\

9.5

cycles

faster to calculate

number

1\ 1\

II

~

of

cycles displayed

as

follows:

1\

I I I

v

J

1\

~

u

tot'

Sweep

rote

: 2

p.sec/

ern

Fig.

3-6

. Frequency cycles per rate

Example:

9.5

waveform on the crt screen. switch

em

age

TIME/CM switch. The result form.

fr

equency

actual frequency

sweep rate of 2 p.sec/cm the number of cycles displayed exactly 9.5 over the 10 divided by 10 gives 0.95 cycles/em.

0.95 cycles/em divided by 2 p.sec/cm, which converts to

centimet~r

= Frequency.

ISame

cydes/10

J.Lsec/cm

2

1.

Set the TIME/CM switch to display several cycles of the

is

in

2. Count the exact number of the graticule.

3. Divide the number

number of cycles per centimeter.

4. Divide the

(If

the

will

As

an

example, using the same signal

measurement

of

display.

signal

as

cm

the

CALIBRATED

HORIZ. DISPLAY

Fig. 3-51 :

0.95

--

-

2

average

have to be multiplied by 0.2 to obtain the

.)

475

kc

made

from

ITotal cycles +

/

cydes

J.Lsec = 475

Be

sure the

position.

of

cycles displayed on the 1 0

of

cycles by 10 to obtain the aver-

cycles/em by the setting of the

is

the frequency of the wave-

switch

em

of the screen.

.

average

10

kc.

VARIABLE

is

at

X.2,

as

The

frequency then

or

0.475

cml +

the

before, w

The

cycles/p.sec,

number

Sweep

Time/Cm

apparent

ith

9.5 cycles

Dual-Beam Phase Measurements

is

of

a

is

For phase-angle measurements using either dual-beam or

multi-trace operation, it

the sweep

play.

TIME/CM

of the input waveform covers each display may gested because it produces a brates the sweep meters.

The relative amplitude phase measurement the horizontal centerline. However, it the phase difference adjusted to

measure phase mode:

1.

in

Dual-Beam Time Measurements.

2. vertical vertical

3. Set both and BEAM controls.

4.

controls so that 1 cycle of the reference waveform covers 8 em Fig. 3-7)

in

degrees of phase

For

instance,

and

VARIABLE

centimeter then corresponds to

is

calibrated

be

used for this calibration. The use

be

the same. Use the following procedure to

angle

Reg

ister the two beams horizontally

Connect the reference phase signal to the Upper Beam

INPUT,

INPUT

the

. Trigger the displays with the Time Base A triggering

Adjust the sweep rate with the TIME/CM

of

the graticule, to calibrate the sweep

.

Reference

Waveform

.~

........

and

.

HORIZ.

Time

Base A trigger

v

~

is

if

the sweep rate

Time/Cm

at

45"

at

1 quadrant

as

long

if

the display amplitudes have been

between two signals

the second signal to the

DISPLAY

1

8

.........

~

/

"'~'-

..

1.9

ern

often convenient to first calibrate

angle

per centimeter of dis-

is

adjusted with the

controls so

8 centimeters

/em.

Any convenient relationship

large

display

(9(t)

of

the signals does not affect the

as

each signal

is

switches to Time Base A

SOURCE

(Jft

~

360°

0

~

['+"

that

one cycle

of

the groticule,

45

degrees,

of

far every two centi-

often easier to read

in

as

described

switch to

/

,..

and

45"

/em

is

and

is

centered on

the dual-beam

lower

and

at

45"

.........

sug-

also cali-

above

Beam

UPPER

VARIABLE

/em

K

/

v

z2

ref

ere line

(see

the

Xl

nce

PHASE

One

complete cycle of a sinusoidal waveform , trigonometric waveform , Phase comparisons between two same frequency can be made with the Type 555 Oscilloscope. Phase angle measurements comparing input formers be used to display the phases simultaneously on the crt screen.

phase relations of sinewaves up to 300

at nectors through similar lengths of coaxial cable. Triggering of the two-trace displays must be from a single source.

and

filters. Dual-beam

X-

Y operation can also

To

retain exact phose relationships between the signals

their sources, they should be

MEASUREMENTS

is

..:onsidered to

or

and

output signals

or

appl

be

more waveforms of the

are

commonly used for

from

amplifiers, trans-

multi-trace

be

used for determining

kc

.

ied to the

or

360 degrees.

operat

ion can

INPUT

other

con-

3-4

Fig.

3-7. Pha

play

Example:

The

second

5. Position both waveforms

zontal graticule line. Adjust the trigger lEVEl control so

the reference waveform starts positive slightly below the

centerline.

6.

be made with the

se-diHerence

calibrated

For

at 4S" / cm.

1.9 cm X

signal

lags

phose angles up to 90", the measurement should

measurement

45

" / cm = 81 ".

the

reference

HORIZ. DISPLAY

waveform

to

from a linear

center on the middle hori-

switch set

by

81 •.

dual

at

beam

X.2 for

dis-

Applications-

Type

555/21A/22A

maximum accuracy. For

measurements must

at

X1.

set between corresponding points on the two phases.

7. Multiply the centimeters of horizontal displacement by

the calibrated angle X.2,

The

the

one

be

the reference waveform.

the left,

it lies

More precise measurements can phase angles, after setting up the display increasing the

TIME/CM switch. Do not ABLE to include this increase. For example, increased by a factor at

X1},

The

time interval between phases by using the brightened portion of display exactly drive both beams. Set the Time Base B TIME/CM switch for a very fast to

SWEEPS ened portion displays MULTIPLIER

Measure the horizontal distance

in

the

"leading"

to

control. The

the calibrated

delayed

sweep

degrees. With the

sweep

is

calibrated

waveform

to the left on the crt display, though this may not

it

leads the reference signal by the phase angle;

the right,

the

and

it

sweep

display

as

sweep

ONCE

of

the display can then

the horizontal displacement

dial.

phase

angles

be

made

with the

rate

(e.g.

45°/

HORIZ. at

9o

is

generally considered to

If

the second waveform lies to

lags the reference signal.

rate

by a factor of 2 or more with the

change

rate

in

degrees/em

of

10 (with the

rate

will then

mode

can also

as

a time marker. Set up the dual-beam

described

rate

FOR

and

EACH

above,

the

SWEEP

'A'

greater

HORIZ.

em)

to obtain the phase

DISPLAY

/em.

be

made

the position of the

if

the sweep

HORIZ. DISPLAY

be

4.5°

/em

be

used to measure the

using Time Base A to

FUNCTION switch

Dl

Y'D

TRIG.

be

read

than 90°,

DISPLAY

in

centimeters

switch set to

of very small

as

described, by

will then

.

The bright-

positioned on the

from the 1-10

switch

be

VARI-

change

rate

switch

X-Y Method

To

measure nals with frequencies up to 300 tion may

provides horizontal deflection other

signal provides vertical deflection . The between the two signals can then lissajous figure displayed.

1.

Connect

INPUT

connector,

HORIZ. INPUT

if

is

2.

Set the HORIZ.

A

TTEN

3. Position the trace on the crt screen deflection factors to produce approximately tion

in

each

X1

0 positions of the HORIZ.

tion

range

panel

EXT

deflection factor over a 1-to-1 0

the

phase angle between two sine-wave sig-

be

used.

In

this mode, one of the sine-wave signals

one

of the sine-wave signals to the vertical

and

the other signal to the rear-panel

connector of the

positions.

direction. The

of the external horizontal input,

. HORIZ. GAIN control adjusts the horizontal

DISPLAY

l

~

.I

[7

kc,

of

the crt

same

switch to one

EXT.

ATTEN

DISPLAY

range

......

~

v

~

the

X-Y

mode

of

opera

beam,

while the

X1

8

and

4

and

phase

of

adjust the

em

of deflec-

EXT.

and

the

ATTEN

the rear-

be

determined from the

beam.

switch set the attenua-

.

J

-

angle

EXT.

Multi-Trace Method

Phase measurements

are

quite similar

as

described tered unless the instrument beam

and

Triggering from usually EXT.

and

In

this case, the trigger signal The input signals and

indirectly

If

a multi-trace plug-in unit with single-channel triggering

is

used, this method should triggering. Apply the reference signal trigger pickoff. Set the trigger SOURCE to PLUG-IN tion of be

applied

display only from the reference signal.

above.

multi-trace mode.

be

provided by setting the trigger

applying

to

or

LOWER

the

multi-trace unit. The triggering signol

through wiring

made

with multi -trace plug-in units

to

those

made

The beams

one

source

an

external time-related triggering signal.

are

then

the triggering signal.

BEAM

with dual-beam operation,

will

is

compared

be

PLUG-IN, depending on the loca-

in

the Type 555 to trigger the crt

not need to

being

operated

will

be

actually the reference signal.

directly to each other

used rather than external

in

required.

SOURCE

to

the channel with

UPPER

be

regis-

both dual-

This

can

switch to

BEAM

will

then

fig.

3-8. Phase-difference

Phase

angle

l«pl

= B lin

2

Sine

4. Center the display

the two vertical distances A

Distance A

points where the

tance B is

cal direction.

5. Divide A by B to obtain the sine of the

between the two signals . The

from a trigonometric table, or from the sine scale on a

slide rule.

If

the display

sine waves

left). or 180° out the display

em

q>

=

4

em

is

the vertical measurement between the two

the maximum excursion of the display

are

is

a circle, the signals

A

= 0.

trace

appears

either

of

phase

measurement

display

5;

in

crosses the vertical centerline.

as a diagonal

in

phase

(tilted

from

an

X-Y

display.

above). Example:

cf>

= 30 °.

the viewing

and B as

angle

(tilted upper right to lower

upper

area

and

indicated

can then

are

90o

be

straight line, the two

left to lower right).

out of

in

phase

calculated

phase

Sine

measure Fig. 3-B

Dis

the verti-

angle

.

of

.

-

If

3-5

NOTES

Tektronix 555/22A, 555/21A Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual