BK Precision 1476 Service manual

@L476

10 MHz,

Dua

l-T

TRIGGERED

race

Osci

SWEEP

I loscope

@"o#6FmN

WARNING

Normal
electrical shock
present.
stop
voltages
or

AC RMS
current under certain conditions. Your
practices
away
significantly reduce the risk factor

precautions:

1.

Don't

necessary.

2. Use
insulated work surface on which to
are

3.

Use
instrument
that could

4.

Always
equipment, where one side of the
This
transformer,

60 Hz in USA), depending upon which way
only
to test instruments or the equipment under

ground
oscilloscopes and most

ground.

use of test equipment exposes

because

electrical shock

An

human heartbeats.

most

more easily

can

should be considered dangerous

that will

from

expose high voltage needlessly. Remove

an insulated floor

not

the time-proven "one hand in the

includes most recent television sets and audio

does

prevent

your

heart in

Turn

or wet. Where insulated floor surface is

damp

probe.

provide a good ground

use an

the

present

this

lead of some

testing

causing l0 milliamps

Higher

produce

contact with

case

equipment

off

material

particularly

Be

isolation transformer to

chassis

of

such equipment may be

a

dangerous

test

instruments

other test instruments with 3-wire

often be

must

vollages

a lethal current. However,

normal work

exposed high voltage, and

of accidental contact

you

if

while making

or a large, insulated

place equipment; and

careful

return

AC

shock

you

to a certain
performed

of

current

pose

an even

and hazardous

habits should include all accepted

know and observe the

housings and

test

connections

pocket" technique while handling an

to avoid

path.

power

the

hazard if the

to a "hot"

contacting

power

is

line

connected directly

equipment. Without an isolation

floating

2-wire AC

test

may

chassis. The

amount of
where exposed voltage
pass

to

through the heart will

greater

voltage

since it

with a

floor

not

available, wear

transformerless

chassis

threat

as

as low

produce

can

that

will

high

voltage. You will

following

covers

in high voltage circuits.

to stand on, and an

mat

make certain

nearby

a

"hot

at line voltage

plug

power

is touched,

result from

power plugs

is inserted.

connecting

ground

danger

because

steer

such surfaces
heavy

to the

from

such

volts

35

only when

metal

but damage

lead

DC

a lethal

current

safety

gloves.

object

chassis"

chassis.

(120

VAC,

Not

the

of

most

is an earth

is

test instruments or any equipment with a 3-wire AC

5.

On
outlet. This
ground.

possible,

If

6.
its high voltage
unexpected

7.

Also
such as on-off switches, fuses,
turned off.

8. Never work
CPR

is

a safety feature to keep the housing

familiarize

points

remember that

alone.

(cardio-pulmonary

yourself

points.

in defective equipment.

AC

Someone

resuscitation)

with the equipment being

However, remember

present

line voltage

should be

is

power

transformers, etc.,

nearby to render aid

first aid is highly recommended.

power plug,

or other

that high

some

on

even

exposed

tested

and the location

voltage

power

input

when

if

necessary.

use only a 3-wire

elements at

may appear

circuit

the

equipment

earth

of

points

Training

at

is

in

INSTRUCTION

FOR

MANUAL

B

10

MHz,

DUAL."TRACE

K.PRECISION

&

MODEL

L476

TRIGGERED

OSCILLOSGOPE

SWEEP

@BMFffiN

6460 West

Chicago, Illinois

C.ortland

60635

Street

INTRODUCTION

FEATURES
SPECIFICATIONS

TABLE

.

OF

CONTENTS

Page

4

OPERATOR'S

OPERATING

Initial Starting Procedure
Single-Trace
Calibrated Voltage Measurement
Calibrated Time Measurement

External
Z-Axis

Dual-Trace

DUAL-TRACE

Introduction
FrequencyDividerWaveforms
Dvide-by-8CircuitWaveforms
DigitalCircuitTimeRelationships
GatedRingingCircuit

DelaylineTests...'....

StereoAmplifierServicing

VideoEquipmentServicing

SINGLETRACE APPLICATIONS

Introduction

Video Equipment

Sigral Tracing
Composite
Sync
VITS
Vectorscope

CONTROIS, INDICATORS

INSTRUCTIONS

Waveform

Horizontal

lnput

Waveform

APPLICATIONS

Video

Pulse

Analysis

(Vertical

Operation

.

and

lnterval Test Sigral)

Observation

Input

Observation

Servicing
Peak-to-Peak

Waveform Analysis

(X-Y

AND FACILITIES

Operation)

Voltage Readings

.

9

9
l0
ll
t2
t2
t2

.

.. . .. 14

....l4

....14

.......14

.....l4

........16

.......16

.......17

l8
l8
l9
l9
l9

2l
23

TELEVISION ALIGNMENT

Introduction
lmportance of Sweep Aligrrment

Sweep Aligrment Methods

Tuner Alignment

IF Alignment

Chroma Alignment

26

26
27
28
29
29

TABLE OF

CONTENTS

page

FMRECEIVERALIGNMENT..

PHASE

FREQUENCYMEASUREMENT

SQUARE

CIRCUIT

MEASUREMENT

WAVE
Introduction
Testinghocedure

AnalyzingtheWaveforms....

DESCRIPTION
General
VerticalPreamplifiers
Mode

logic
VerticalAmplifier
TriggerCircuit
SyncAmplilierandlnverter
AutoSweep
HorizontalAmplifier
ChoppingOscillator
I VoltCalSignal
PowerSuppty
BlockDagram

TESTING

OF AMPLIFIERS

...

....3I

....

...... 33

........34

....34

....38

.....38

.. .. . . 38

.......38

....38

...38

......40

.....4O

......4O

........40

.....4O

....50

3l

33

I',IAINTENANCE

WARRANTY

WARRANTY

OPTIONALACCESSORIES...

AND

CALIBRATION....

INSTRUCTIONS

........

........ 43

.....44

.....

40

43

The B & K-Precision
loscope
observing
Dual vertical
of
waveforms
simultaneous
permits
rate waveforrns.

is a laboratory-quality,

and measuring

inputs

waveforms.

two

are

chopped

viewing.

simultaneous

DUAL TRACE

FULLY

SOLID STATE

TRIGGERED

SWEEP

LARGE

SCREEN

CALIBRATED

VOLTAGE SCALES

CALIBRATED

SWEEP SPEED

WIDE BANDWIDTH

INTRODUCTION

Dual-Trace

Model

waveforms in electronic

provided

are

Low-frequency, low repetition rate

at a 200

Alternate sweep

viewing of high-speed, high repetition-

1476

professional

for

kHz rate to

instrument

simultaneous viewing

of

the two inputs

Oscil-

circuits.

provide

for

for

FEATURES

input waveforms can be

Two
viewed

taneously, as

Only

filament. All
transistors,

e ffect transistors) and

The 1476's

pres€ntations is beyond
son
oscilloscopes.
at rest
being
they

Fully
allows
waveforms
ing.

synchronized

trigger.

The 130 mm

diameter cathode
easy-to-read

8 x l0 cm
area.

Accurate measurement of the
stantaneous

ferent attenuator
Channel A and Channel B.

Accurate time

l8

DC to

nSEC rise time assure distortion-

free,

at

either

the cathode

with non-triggered

until

observed,

are

adjustable

the desired

Waveforms can

different ranges.

l0

high

high frequencies.

singly

desired.

ray tube uses

other

diodes, FET's

stability

sweeps

The

triggered by

to assure

always synchronized.

trigger

portign

to be used

to an

(approx.

ray tube

presentation

rectangular viewing

voltaees on I I

ranges for

measurements

MHz bandwidth

resolution

or

simul-

stages

of waveform

for trigger-

external sync

5.1 inches)

presentation

use

(field

IC's.

compari-

sweeP

remain

the

signal

that

threshold

of the

be

also

gives

on an

ln-

dif-

both

on

35

and

dual-trace

The
width, wide range of sweep speeds, and
provided,
of
electronic equipment, research and
laboratory instruction.

make this the ideal oscilloscope

applications,

EXPANDED

SCALE

a

HIGH

SENSITIVITY

VIDEO

SYNC

VECTORSCOPE

CALIBRATION

SOURCE

Z-AXIS

INPUT

feature,

including troubleshooting and

together

A five time rtragrification
the horizontal sweep allows close­up
the
magnification
mum

gSEC/cm.
Permits

impedance, l0: I

probes
measurements, thus assuring less
circuit

A

built-in sync separator circuit
included
television
VIDEO

are automatically selected at sweep

times of 0.5 SEC/cm to 0.

mSEC/cm for viewing

frames. Horizontal sync

automatically
times of 50
for viewing television lines.

The unit may be used as a vector-

scope to

exactly
vision manufacturers.

A

built-in calibrated I volt
t o -peak square wave
checking and
vertical
tional

Intensity modulation
cluded for time or frequency
kers.

brightness increases in
state, decreases in logic

with the l0

development, and

examination of
waveform. In

provides

sweep speed

the low-capacitance, high-

to be used for

loading.

specifically

signals.

SYNC,

selected at sweep

pSEC/cm

provide

as speciiied by color tele-

recalibration of the

amplifiers

equipment.

Compatible

MHz

high

sensitivrt)

for

a broad

portion

a

addition,

attenuation
virtually

for viewing

When

verticai

sync

I

to

a color display

without

capability

with

TTL logic;

logic high

low state.

band­range

repairing

(5X)

of
of

the 5X

a maxi-

of

0.2

all

is

using

pulses

television

pulses

are

pSEC/cm

peak-

permits

addi-

in-

mar-

1

WIDE

RANGE OF

SWEEP SPEEDS

Sweep speed
to 0.5 SEC/cm
speed
forms from DC

range of

necessary for

to l0

pSEC/cm

1

provides

viewing

MHz.

every

wave-

MECHANICAL

FEATURES

Carrying
molded fingergrip also doubles as tilt

stand. Locking detent each

allows adjustment of
Rear feet
face-up
wrap for
bezel over face of
dard oscilloscope camera for making

waveform

handle with comfortable

22-l/2"

support

position

and double as

power

storing

photographs.

viewing

oscilloscope in

CRT

angle.

Slotted

cord.

mounts stan-

cord

SPECIFICATIONS

VERTICAL AMPLIFIERS

Deflection

Calibration

Frequency

Risetime
Overshoot

Ringing

Input
Input Capacity
Max.

Operating

Chop Frequency
Channel Separation

Factor

Accuracy

Response

Resistance

Voltage

Input

Modes

0.01
calibrated

quence.
!
DC: DC to l0 MHz

AC:2Hz to l0
35 nanoseconds.
3%

display.
3% or less

display.

I megohm, t 57o.
22

300
p'p.

Channel
Channel B
Dual-trace automatically

at
slower; alternate trace
cally selected
times.

2OOkHz(t2Vo).

Better than 60 dB

(CH

A and CH

V/cm to

Variable

5%

on all ranges.

or less at I @ kHz

(t3

pF

(DC +

V

A only.

all sweep times of I mSicm

B)

V/cm in I I

20

ranges

at

pF).

only.

in l-2-5 se-

between

dB)

G3

(-3

MHz

100 kHz squarewave

AC

for

@ |

dB).

squarewave

peak)

or 600

chopped

automati-

all faster sweep

kHz.

ranges.

V

and

Video Sync

HORIZONTAL

B Input)

CH
Deflection
Frequency
Input Resistance I
Input Capacity

Maximum

Voltage

X-Y Operation With

Factor .01

Response

Input 300

Vertical and
circuit
composite
chronized and
LINE
sync switched automatically
SWEEP
FRAME 0.5 SEC/cm
mSEC/cm
LINE
(horizontal

AMPUFIER

DC

22

p-p.

CH B
becomes
the
input
tion
tal

horizontal

provided

(horiz.)

:

(Horizontal

V/cm to 20 V/cm.

to I MHz ( - 3 dB).

megohm

pF

V

SWEEP

CH

(horizontal).

control

position

so that any

video waveform can be

expanded

and

TIME/CM switch.

(vertical

50

sync

(t3

(DC

position,

the
B input

sync

pSEC/cm

pulses).

(nominal).

pF).

+

AC

TIMEICM

the CH A input

Y

input

becomes the horizon-

control.

sync s€parator

portion

syn-

viewing.

for

FRAME

to

lnput through

peak)

(vertical)

becomes

The CH B

(vert.)

to 0.1

pulses).

pSEC/cm

I

or 600

switch in

the

posi-

and

of

by

V

X

SWEEP CIRCUITS

Sweep System

Sweep Time

Sweep Time Accuracy

Magnification

Sweep

Horizontal Linearity

TRIGGERING

Source

Slope

Triggering

Range

(Common

to CH A and CH B)

Triggered and automatic. In
matic mode,
without

I
calibrated
quence.

+
Obtained by enlarging the

sweep
mum

gSEC/cm.

3% or

INT
sensitivity). MODE
sourceofinternaltrigger;
signal is the
the
the

source in the
Positive

ly

AUTO.
INT: 20 Hz

EXT:

input

sigral.

pSEC/cm

<q^

CH A and DUAL

CH B signal

variable

to 0.5

ranges,

Variable

5 times from

speed becomes

sweep

less

distortion.

and EXT

triggering

CH B mode.

and negative,

level

to l0 MHz
deflection
cathode ray
DC to l0

is obtained

sweep

SEC/cm in 18

in l-2-5

between ranges.

center.

(l

V

switch selects

the CH A

source in

modes,

is the triggering

continuous-

control;

as

tube).

MHz.

pull

(min.

measured

auto-

se-

above

Maxi-

0.2

p-p

and

for

I cm

on

CALIBRATION

INTENSITY MODULATION

Voltage

Input Resistance

POWER

Input

PROBES

Model
Attenuation
Input

Connector
Tip

REQUIREMENTS

No.

lmpedances

VOLTACE

I

frequency.

TTL logic-compatible,
increases
decreases

l0 kO

120
20
approved for oscilloscopes.)

Fig.

PR-31,

Combination

l0:l = l0 megohms,
Direct

BNC

Spring-loaded,

p-p

V

square

brightness;
brightness.

(nominal).

or 240 V AC,

(3-wire

watts.

51.

PR-35, PR-36,

=

I megohm,

(t

wave

high logic

low

tlo7o,

line

cord, CSA-

PR-37.

l0: I

and direct.

18

120

hook-on tip.

5%)

at

logic

5O/6O Hz,

pF.

pF.

line

-

-

See

Fig.

|. Front panel

controls

7
I

9

r0

12

and indicators.

OPERATOR'S

Cathode

l.

the
Scale. The

2.

marks
rneasurements.

Pilot Lamp.

3.

4.

SWEEP
selector. Selects calibrated sweep

(microsecond per

steps. In
internal sweep

provide

CAL

5.

peak-to-peak

cy.
attenuators.

< >

6.
position
dual
cation
when

7

TRIGGERING LEVEL Control. Sync level adjustment
determines
starts;

(+)

switch selects automatic

(PULL

generated
EXT TRIG Jack.

E.

signal.

SYNC

9.

following

SLOPE.
waveforms except television composite

(+)

(-)

VIDEO. In
television composite

10.

SOURCE
sweep.

INT Sweep is triggered by

Ray Tube

waveforms

for voltage

Lights

TIME/CM Switch.

the CH B

horizontal sweep.

|.-P Terminal. Provides

This is

POSITION

equals most

sweep; the vertical sync
selected
and horizontal sync
selected

(+)
(-)

EXT Sweep is triggered by an external signal applied

used

of traces

trace mode).

when

pushed

points

(-)

equals

AUTO).

even without an input signal.

Switch. Four-position

positions.

The SLOPE

Sweep is triggered
waveform.

Sweep
waveform.

lor

for sweep
Sweep is triggered on
Sweep is triggered

Switch. Selects

switch is in CH A or
Sweep is triggered by Channel

MODE

at the

(CRT).

viewed.

are

8 x

l0 cm

when oscilloscope is tumed on.

centimeter)

generator

wave input

square

for

Control. Rotatitin adiusts horizontal

(both

Push-pull

pulled

in.

on

most

positive point

When automatic

Input

is triggered on

VIDEO

the

sweep times

times

switch is in CH B

EXT TRIG

This is

graticule

(vertical)

position,

calibration

out

waveform

negative

positions

video signal are used to trigger the

pulses

and time

Horizontal

this switch disables

permits

and

signal at the

of the vertical amplifier

traces

switch

(PULL

triggering

terminals for external trigger

positive-going

on

negative-going slope of

positions,

(frame)

pulses

of

0.5 SEC/cm
(line)

pSEC/cm

of 50

positive-going

on negative-going

triggering source

CH A sigrral

DUAL

jack

8.

CONTROLS.

the

screen

provides

times of I

to

0.5 SEC/cm

when

selects 5X magrifi-

5X MAG): normal

slope

point

of triggering.

triggering,

lever switch

used

are

the sync

position.

position.

calibration

(horizontal)

sweep time

pSEC/cm

the CH B input to

calibrated

line frequen-

operated in the

where

of triggering

when pulled

a sweep

for

viewing all

video sigtals.

pulses

are automatically

to 0. I mSEC/cm,

are automatically

prSEC/cm.

to 1

sync

sync

when MODE

B

sigral

which

on

in

l8

the

I volt

sweep

and

Push-pull

out

is

with the

of

slope

of

pulse.
pulse.

for the

when

INDICATORS

Channel

ll.

ment
adjustment
CH

Channel B

12.

adjustment

13.

Channel
B. Jack
SWEEP

Ctrannel B DC-GNDAC Switch.

14.

DC Direct input of AC and DC

GND Opens sigral

AC

Channel B.

15.

Channel B.
from
horizontal sensitivity
switch

MODE

16.

basic

CH A Only

DUAL Dual-trace operation; both

CH B Only the input signal to Channel B is

17. Channel
Channel A.
from

18. Channel A DC-GNDAC

DC Direct input of AC and DC component of input

a

GND Opens sigrral

AC Blocks DC

19. Channel A
A.

l). Channel

adjustment for

21. Channel A POSITION
justment

FOCUS

22.

INTENSITY

23.

brightness

FOWER

24.

FACILITIES

AND

POSITION Control.

B

for Channel
position.

B

B INPUT

becomes external

TIME/CM switch 4 is

signal.

amplifier.
the
when

Blocks

to

.01

4 is in the CH B

Switch. Three-position lever switch;

operating modes of

played

Channel B input signals are
separate

played

A VOLTS/CM

to 20 volts

.01

sigral.

amplifier. This

the

when

A DC BAL

for

Control.

Switch. Turns

B trace. Becomes

when SWEEP

DC BAL Adjustment.
for

Channel B

Jack. Vertical input

path

provides a zero-signal

This

position

VOLTS/CM
Vertical

Vertical

position

INPUT Jack. Vertical inputjack ofChannel

of trace.

ofwhich can

performing

DC component

sensitivity

20 volts

position.

the

input signal

as a single

traces.

as a single trace.

sensitivity
per

path

provides

which

of

performing

component of input signal.

Adjustment. Vertical

Channel A trace.

Channel A trace.

Control.

Vertical

TIME/CM switch

Vertical

trace.

horizontal

in the CH B

component

grounds

and

DC measurements.

Switch.

per

when the

the

Switch.

cm.
Switch.

and

DC

Control.

Clockwise

unit on and

be used as a

of input

Vertical

is calibrated

This

cm.

oscilloscope.

to Channel A is dis-

trace.

Vertical

is

calibrated

grounds

a zero-sigral base line,

can be

measurements.

Vertical position

rotation increases

position

horizontal

jack

input to vertical

signal.

control

SWEEP

the Channel A and

displayed on two

input to vertical

used

off.

adjust-

position

in the

4 is

Balance

DC

of Channel

input when

position.

of input

line,

base

reference

attenuator

in I I steps

attenuator

in I I steps,

as a reference

DC balance

for

adjusts

TIME/CM

selects the

dis-

for

ad-

the

VARIABLE

25.

the extreme
is calibrated.

VARIABLE

CH B

26.

adiustment.
In-the extreme
attenrator

CH A VARIABLE

n.

adjustment.
In-the extreme
attenuator

Control.

Fine sweep

clockwise

Control.

Fine control

clockwise

is calibrated.

Control.

control

Fine

clockwise

is calibrated.

of

(CAL),

B

CH

B vertical

CH

position

(CAL) position,

A

CH

A

of CH

(CAL)

time adjustment.

the sweep

vertical

attenuator

In

time

sensitivity'

vertical

the

vertical

attenuator

vertical sensitivity-

position, the vertical

29.

Line Cord

AC
loscopes.

(See

Probe

30.

combination
for

use
designed
input impedance
capable

Vector Overlay

31.
for

of operation

vectorscope

(See

Fig. 3).

l0: l/Direct

with this

for use with

of

(Not

operation.

Fig. 2). CSA-approved

The B & K-Precision

probes

oscilloscope.

an oscilloscope

I megohm

up to 10

Shorvn).

have been

However,

having a nominal

shunted by

MHz, can be

Interchanges with

for oscil-

ModelPR-31

designed

probe

any

pF

35

and

used.

scale

INT MOD

28.

Jack. Intensity

modulation

DC BALANCE CONTROL

(One

on each

1.

side

PULL

)

APART

(Z'axis) input.

Fig.

2. Rear

CRT

ADJUSTMENT

COMBINATION
AND

CORD

and side

panel

facilities.

ROTATION

FEET

WRAP

2829

t-r,_tfj1-

--

2. ROTATE 180"

PUSH

3.

1O:1

ATTENUATION

BACK

TOGETHER

Fig.

3.

PROEE

hobe

P ROBE

COMPENSATION

(PR-31

)

probe

Adlust

square wave display while observing

from

signal

COMPENSATION ADJUSTMENT

ADJUSTMENT

compensation

cal J1 1V

details.

p-p

for

ACK.

(PR-35)

best

OPERATING

INSTRUCTIONS

INITIAL STARTING PROCEDURE

i Set PO\l ER switch 24 to OFF

l. Connect

3. Set
control
their ranges.

PUII

4.
position.

5. Set
DC-GND-AC

6. Set MODE
single-trace operation
trace operation.

7. Tum on oscilloscope
ON

8. Wait

warm
mode)

9. If
INTENSITY
observed.

10. Adjust FOCUS
for

I 1. Readjust

center the

12. Check for

and 20
CALIBRATION
ments

The oscilloscope

measurements.

power

cord 29 to a I

CH A

position.

no trace appears, increase

the

POSITION

I I

and<>POSITION

TRIGGERING

CH A DC-GND-AC

switch
switch 16

Pilot lamp 3 will light.

few

a

seconds for

up. A trace

should

thinnest,

position

traces.

as described in the MAINTENANCE

require

(two

appear on the face of

control 23

control 22and INTENSITY

sharpest trace.

controls 6,21 andl I if necessary,

proper

portion

checking

is now ready

LEVEL

14

or the DUAL

by turning

adjustment of

l7-volt,

control

control 6

control 7 to

switch 18

to the

GND

to the CH A position

the cathode ray

traces

if operating

(clockwise)

until the trace

of this

periodically.

only

position.

50160 Hz outlet.

21,

CH B

to the centers of

and CH B

positions.

position

POWER

DC

manual. These

for making

switch

tube

in the DUAL

the CRT.

the

BAL controls 12

POSITION

the AUTO

for

for dual-

to

24

(CRT)

to

setting of

is easilv

control23

to

AND

adjust-

waveform

the l0:l
capacitance
impedance
when

J.

SetCH
only the AC
most measurements
being measured
the
and the DC reference,
frequency
The GND
ground
readings.

4.

Connect
equipment
the
measured.

a. If

b. The

5.

Set CH A VOLTS/CM

gives
vertical deflection.
probably
concemed
speed,

desired
duces

jicient

position

in the DIRect
(low-capacity

possible,

A

DC

point

the
less AC
former to prevent

measurement
when

2 to

which presents

at least I

tigger signal

to decrease circuit loading.

DC-GND-AC

component

position

reference

ground

number

includes a large DC

for measuring

waveform

position

clip

under

in the

peak-to-peak

using the DIRect

be

test. Connect

circuit

equipment

powered

(two

6

cm

unsynchronized.

with

adjusting synchronization
of waveforms.

cm vertical

and I megohm with

is required only when

is required, such

WARNING

should not exceed

to synchronize

position.

position)

switch

and

(below

of

under test is a transformer-

item, use

dangerous electrical

to six large

The

l8 to

(this

the

is

must

be used if the

both the

any

and

Hz)

5

probe to

where the waveform

voltage at the

switch 17

display on the

a

chassis

the

an

position

The remaining

stable display

Any signal

deflection

l20pF shunt

The higher input

should

AC for measuring

normal

component). Use

AC component

time a very low

is

to be observed.

as for DC voltage

ground

tip of the

isolation

point

600 volts

of the

position

to

a

squares on the scale)

develops suf-

the

sweep.

be used

position

a zero-signal

shock.

probe.

screen will

and

showing

point

of the

probe

is

to be

trans-

of

that

steps are

sweep

pro-

that

for

to

the

Never

allow
remain
few

seconds.
burned. Reduce
motion

SINGI,E-TRACE

Either

single-trace

following

the

Perform

l.

with

the
connect the
The following

B & K-Precision Model PR-3
For

2.

all except low-amplitude

are set for

(below

forms
DIRect.

DIRect, or

to
input

impedance

a small spot of

stationary on the

The screen mav

by

Channel A or Channel

operation. For simplicity,

instructions.

the

MODE

See Fig. 3

intensity

causing it to

WAYEFORM

steps

switch

probe

instructions assume

l0: I attenuation. For low-amplitude

volt

0.5
vice

with

CAUTION

high brilliance

screen for

become

-or

sweep.

OBSERVATION

of

the "Initial Starting Procedure"

16 in

the

to the CH A

cable

i combination

peak-to-peak),

for

changing

versa.

only l8

The

probe

more
permanentlv

keep

ihe

spot

B

can be used for

Channel A

CH A position.

INPUT

the

waveforms,

set the

the probes

has

shunt

capacitance

a l0 megohm

pF

than a

is used in

jack

use of the

probes.

the

probe

from

to

iir

Then

19.

probes

wave-

for

l0:l

in

6.

Set SOURCE
provides
observed

waveforms

external

an

switch

cable should
to the external

Set SYNC switch 9 to the

for observing
to
all

the

the
negative-going

unknown, the

8.

Readjust TRIGGERING

synchronized

the

that will
in the

disappear
sweep,

amplitude waveforms.

should

the SLOPE

other

sweep is to

(-)

control may

such

switch l0 to

internal

is

should

types

position

produce

center

if there

sync

also used to

be viewed

sync

placed

be

be connected from

sync source.

television

(+)

or SLOPE

of waveforms. Use

be triggered

if the

wave.

SLOPE

display

be

a sweep,

portion

when

as

INT

the

that the waveform

so

trigger the

source is required,

without

pushed

is inadequate

using internal

in the EXT position

the EXT

VIDEO(+)

composite

by a

sweep is to

If the type

(+)

position

LEVEL control

which

of

measuring

If no sweep

video

(-) positions

the

positive-going

be triggered

may be used.

jitter.

in and rotated

its

As a

is usually

range.

signal

DC or

or

of waveform

can be obtained,

position.

sweep. Most

sync. When

the

SOURCE

and

jack

TRIG

(-)

positions

waveforms

for

observing

(+)

position_if

wave,

7 to obtain

starting

The trace

to trigger

extremely

point,

to

any

somewhere

This

being

or

or

by

is

point

will

the

low

a

8

a

a

pull

the

control

out

(PULL

AUTO) for

triggering.
Set SWEEP

9.
of waveforms. This

portion

a
progressively

is

This

because the

repetition rate

TIME/CM switch 4

control may be set for viewing

of a waveform,

dimmer as a smaller

sweep speed

does not change.

for

the desired

the

but

portion

increases

trace becomes

but the sweep

NOTE

When

using very

rates, the operator

fast

sweep speed

may

low repetition

at

wish to operate

intensity control toward maximum. Under

conditions, a

extreme left of the

retrace "pip"

This does

trace.

may appear at the

not in any way

affect the oscilloscope operation and may be

disregarded.

10. After

obtaining

9,

step

it is sometimes desirable to make a final

adjustment

(-)

The
waveform
(+)

direction

at

direction selects

the desired number of waveforms,

of

the TRIGGERING LEVEL

which

the most negative

selects

sweep triggering will occur

positive point

most

the

automatic

number

is

displayed.

with the

these

control 7.

point

and the

only

as in

on the

on the

waveform
control
desired

I l. For

outward

a close-up view of a portion

which

at

may

be adjusted to start the

portion

of the waveform.

on the<)POSITION
the sweep by a factor
displays only

portion

a
control clockwise,
center, turn the

on the

control to return the

non-magnified

CALIBRATED

Peak voltages, peak-to-peak

-

voltages
easily
Dual-Trace

of a specific portion

and

accurately

Triggered

Adjust

l.

controls

waveform to

2. Set

CH A

vertical

deflection

center

the

the

to

left

and to

control

condition.

VOLTAGE

Sweep

previously

as

be measured.

VOLTS/CM

limits of the vertical

sweep triggering

of the

will occur.

sweep on

waveform,

The

any

pull

control 6. This expands

(5X

of five

partion

magrification)

of

the

sweep. To view

and

of center, turn the<>POSITION

portion

view

counterclockwise.

sweep to

MEASLJR-EMENT (See

voltages,

of the

measured

complex

on the

to

the right of

Push

inward

the normal,

Fig. a)

DC voltages

waveform
Model

1476

and

Oscilloscope.

instructed

switch 17 for

possible

without exceeding

to

display the

the maximum

scale.

are

the

POSITI

ON CONTROL ADJUSTE
SO THAT
FORM
A HORIZONTAL

BOTTOM OF

ALIGNS

EXACTLY

REFERENCE

EXAMPLE:

VERTICAL

PROBE

PEAK-TO-PEAK

.} POSITION

TOP OF WAVEFORM

VERTICALSCALE MARKER
AND

WAVE-

DEF

VOLTAGE/CM

ATTENUATION

WAVEFORM

CONTROL ADJUSTED

EASE

WITH

LECTI ON

.O2Y x

D

LINE

4.2

READING

OF

4.2cm
.O2

.084V

0.84V

CROSSES

v

10

SO THAT

CENTER OF

FOR ACCURACY

qTo1"t

t

VOLTS/cm

SET

.o2v

PROBE

TO

10:1

ATTENUATION

l0

Fig.

4.

Typical

voltage measurement.

vertical

Read the amount

3.
the s;ale. The
rea.ltusted
:erJrng
::.r'
reierence
G\D
deflected
The
and

4. Calculate

ri desired.

CH A

with the

position,

when the switch

trace deflects upward

downward

the voltage

vertical deflection

setting

(see

l7

ro

of

CH A

the reference

shift

When measuring a DC voltage, adjust

POSITION

CH A DC-GND-AC

then note

for a negative voltage input.

(in

example

voltage reading displayed

l/l0th the actual

probe

is

set

displayed

when

voltage being measured

for l0: I attenuation.

probe

the

ment,

5. Calibration

accuracy
occasionally checked by
peak

square

jack

5. This calibrated
peak-to-peak.

volt
dicated, see the

wave

signal

If a

"MAINTENANCE AND

TION" section of the manual

deflection

POSITION control

point

for easier scale

control 2l

to

switch

the amount the

placed

is

for a

in the

positive

reading as follows:

VOLTS/CM control

by the

cm)

in Fig.4) Don't

on the

forget that the

oscilloscope is only

(in

a convenient

DC

voltage

Multiply the

from

cm)

2l may be

l8

in the

trace is

position.

input

when the

voltage is

measure-

is set

The actual

for

DIRect

of this oscilloscope may be

observing

available at

the I volt

the CAL lV

peak-to-

P-P

source should read exactly I

need for recalibration

is in-

CALIBRA-

for

complete

procedures.

MEASUREMENT

CALIBRATED

Pulse width,

waveform time

other
measured on
ments

from
possible.
visible at one time.
moving
the beginning and

TIME

waveform

this oscilloscope.

second

.5

At low sweep speeds,

However,

from left to right

ending

to spot.

Adjust

l.

controls

display of

2. Set the SWEEP
possible

display

as

the desired

TIME/CM control

of the

measured, usually one

3. If necessary, readjust
trol 7 for the most

Read the

4.
between the
control 6
measurement

amount of

points

may

be readjusted

points

easier reading.

5. Calculate the

time duration

(See

Fig. 5)

periods,

durations

down

across

points

previously described

circuit delays
easily and accurately

are
Calibrated
to 0.1

entire

the

the bright

tinp rneasure'

microsecond are

waveform is not

spot

the screen, which

the measurement easy

of

can

for

waveform.

4 for

the

waveform

segment

cycle.
the TRIGGERING

display.

stable

horizontal

of measurement.

to aligrr

LEVEL con-

deflection

ThecPOSITION

one of the

with a vertical scale marker

follows: Multiply

as

and all

seen

be

makes

stable

a

largest

to be

(in

cm)

for

the

<)

POSITION
THAT

FORM
REFERENCE LINE. EDGE
MAY NOT BE VISIBLE ON
FAST PULSES; IN
ALIGN
BEGINS.

POSITION

THATTRAILING EDGE

CROSSES HORIZONTAL
FOR ACCURACY

EXAMPLE:
HORIZONTAL

c.

CONTROL

LEADING EDGE OF WAVE-

ALIGNS

WHEREVER WAVEFORM

CONTROL

SWEEP

TIME

PEBIOD)

OF WAVEFORM

ADJUSTED

WITH l. r ERTICAL

THIS CASE

ADJUSTED

AND EASE

DEFLECTION

TIME/CM

DURATION

SO

VERY

OF WAVEFORM

SCALE

SO

MARKER

READING

OF

=

6.35cm

1 OpSEC

­=

63.SpSEC

HORIZONTAL

DEF LECTI ON

O.JJ

cm

f

ol-ol"t

SWEEP TIME/CM

'l0l,l

set to

SLOPE

tto start syveep

negativejoing

INT

sec

set to

edgel

Q
on

FREouENCY -

=:-

IIME

=

.0000635 sEc

15,750 Hz

Fig.

5.

Typical time

DISPLAYS
RECEIVER
HORIZONTAL

measurement.

SHOW TYPICAL TELEVISION

WAVEFORM AT GRID

OUTPUT TUBE

OF

ll

horizontal

deflection
switch 4 setting
when the
divided

5X magnification is used, the result must be

by 5 to obtain the actual time duration.

6. Time measurements
especially
started
waveform

true when measuring delays. The

by a

measured in a subsequent
measurement
and the

subsequent

(in

(see

example in Fig. 5).

often

sync sigral

of the

display

waveform.

cm) by the SWEEP TIME/CM

require external

from

one

circuit. This allows

between the

perform

To

urements using external sync, use the following
a. Set the
b. Connect a

source

c. Set the SYNC

position

d. Readjust

necessary for

e.

If measuring
start of the

7. Another excellent method for
with

dual-trace operation. The

SOURCE switch l0 to the EXT

from the EXT TRIG

cable

of sync sigral. Use a

switch

for

proper polarity

the

short shielded cable.

9 to the

SLOPE

for the

the TRIGGERING LEVEL

a stable

a delay,

sweep

waveform.

measure

to the

the

start of the waveform.

measuring

procedures
the "DUAL-TRACE APPLICATIONS"
manual,

EXTERNAL HORTZONTAL

For some measurements,

tion sigral is required.
measurement,
tion

and the X input
horizontal
phase

measurement,

where the Y

input may be a sinusoidal wave,

input must be 10 mV

voltage of

any
satisfactory operation. To

the following

use

This is also referred to

provides

or an external sweep

per

cm

mV or

100

use an external horizontal

procedure:

1. Set the SWEEP TIME/CM
the CH B

2. Use
Channel B

3. Adjust the
CH B VOLTS/CM

position.

the Channel A

probe

for

amount of horizontal

probe

the horizontal input.

control 15.

4. The CH B POSITION

horizontal

control

position

is disabled.

control, and the

input

control I I

INPUT

extemal

an

provides

horizontal

of

deflection or
greater

switch

for

the vertical

(X-y

OPERATTON)

horizontal

is sufficient for

4 fully

deflection with the

now serves

NOTE

Do NOT

X-Y operation.

to adjust

5. All

Z.NilS

.The

modulated
rygks 99

INT MOD
oscilloscope will govide
of the trace.

horizontal

sync

controls

INPUT

trace

(Z-aas

required.

(intensity

See Fig.

use

the

Use

displayed

input) where
A TTL

modulation)

6.

PULL

5X MAG

the

CH B VOLTS/CM

gain.

are disconnected

on the

screen

frequency-

compatible

allernate

sigrral

j

ack 24 on

brightness

control durine

and have

may

t2

Remember,

sync. This

sweep is

circuit and the

pulse

sync
such meas-

steps:

position.

jack

8 to the

(+)

(-)

or

sync signal.

control 7 if

from

time

the

time delays is

given

are

in

section of the

deflec-

as an X-Y

vertical

deflection.

such

deflec-

The

for

as

voltage. This

greater;

thus

input,

clockwise

to

input and the

the

as

POSITION

<>

controT

no effect.

be intensity

or

time-scall

applied

th-e-rear

and

at the

of

the

blanking

is

f

\

l

t

Fig.

6.

Oscilloscope

DUALTRACE
(Refer

to Fig.

In observing
and B,
frequency
the

other although
An example
mulliplier.
on Channel
of

this reference

In

this way,
synchronized,
with

the Channel

phase

or frequency
simultaneously,
both

waveforms

To display

tion,

use the following procedure:

Perform

l.

2.

Connect
and CH B IMUT

If

the recommended

3.

WAVEFORM

7)
simultaneous

it is necessary

or

that one

the basic frequencies

of this

The

A, for

is in

reference,

example,

frequency

when the

thq

display

A

display.

relationship

it will

in

sync for

two waveforms

the

steps of

oscilloscope probe

jacks

oscilloscope probes

should
peak-to-peak
forms
for

be used

except for

or

less. For

the DIRect position

changing the

probe
Whenever possible,
capacity l0: I

4. Set MODE
traces should

5.

Adjust

place

to
trace,

and

mark

on the

6.

Set both
and 14 to
most

measurements

being measured

position

switch 16

appear on

CH

A

and CH B POSITION

the

Channel

adjust

both

scale.

the

CH A

the

position.

AC

include

't

t

I

t

\

trace with Z-axis

OBSERVATION

waveforms

that

the waveforms

of the

waveforms

checking a frequency

or

"clock" frequency

and the

will

be displayed

waveform

on Channel

If two waveforms

to

be difficult if

any useful

simultaneously

the "Initial

19

and 13.

B

& K-Precision

are used,

the lower

should be

from

use the

to minimize

to the DUAL

the

screen

A

trace

traces to

and CH B

This is the

and must

a large

t

\

I

t

t

input.

on

be

be

synchronized

may

be different.

can be used

multiple

or

submultiple

on

display

each

of Channel

B will

other

also be in

are displayed

not impossible

observation.

for

Starting Procedure."

cables

to both

Model PR-31

10 :

waveforms

I attenuation

of

amplitude

used.

l0:l

to DIR

high

or vice

impedance,

circuit

loading.

position.

controls
above the
a convenient

DC-GND-AC

switches

position

be used

DC

if

component.

channels

related

divider

ChanneiB.

A

sync

having

no

tb lirck

observa-

the

CH A

0.5 volt
wave-

See Fig.

veisa.

low

Two

2l and

ll

Channel

reference

l8

for

used

points

the

A

in

to
or

is

3

B

gound

Connect
g:ound

-.i
*aveiorms

*aveform will

the

the equipment

of

probes

the

are to be measured. The sipal to which the

be synchronized

Channel A input

to

for

of the

clips

under

points

in the

intemal sync operation.

WARNING

the equipment under test is a transformer-

a. If

less AC unit. use an isolation transformer to

prevent

b. The

dangerous

peak-to-peak

measurement should not

probe

the

R

Set the VOLTS/CM controls

B to

and

deflection.

is

position

a

The displays on the screen will

unsynchronized. The

those outlined for single-trace operation, describe

to

procedure

the

electrical shock.

voltage at the

in the DIR

used

that

remaining steps,

for

obtaining

exceed

l5

gives

displays.

Set the SOURCE switch

9.
provides

internal sync so that

l0 to

the Channel A waveform
being observed is also used to
in dual-trace operation, a sync source

point

measurement

set the SOURCE switch to the EXT

case
position

to

8

the sync source.

the SYNC switch

Set

10.

positions
waveforms, or
positions

and connect a cable

for observing

for observing

for Channel A is required. In this

from the EXT TRIG

9 to the VIDEO(+) or

te.-vrsion composite video

to the SLOPE

other types

all

probes

to the

test.

Connect

circuit

must

be applied to

600

the tips

where the

point

volts.

chassis

of

position.

17 for

and

Channels A

2 to 3 cm vertical

probably

although similar

stable,

the

synchronized

position.

INT

trigger the sweep.

other

than the

(external)

(+)

or SLOPE

waveforms.

of

the

if

be

This

Often

jack

(-)

(-)

(+)

Use

the

positive-going

a
sweep

I l.

Adjust
stable, synchronized sweep.
control

produce

will
the

center

if there is inadequate signal

when measuring

as

no sweep can be obtained,

positions

if the sweep is

wave, or to the

is

triggered by a negative-going

to be

TRIGGERING LEVEL
may be

pushed

a sweep,

portion

in and

which is usually somewhere

of its range. The

extremely low amplitude signals. If

(-)

control 7

As a

rotated to

trace will disappear

to

trigger

pull

out the control

AUTO) for automatic triggering.

t2.

Set SWEEP
of waveforms. This

portion

a
progessively

13.

After obtaining the desired number of

TIME/CM

switch

control

of a waveform, but the trace becomes

dimnrer

a smaller

as

step 12, it is sometimes

for the

4

may be set

portion

desirable to make a final

adjustment of the TRIGGERING

(-)

The

point
will occur

positive point
triggering will occur. The
start the sweep

direction of rotation selects

on the sync waveform at

and

on

the

the sync

direction selects the most

waveform

(+)

control

on

any desired

which

may be

portion

waveform.

The obsewed waveforms of

14.

expanded

be

on the <>POSITION

rotated

be
left

desired.

right extremes of

and

Push

by a factor of 5 by

control

clockwise or counterclockwise

inward on the control to retum the

Channels A and B can

This control can then

6.
waveform

the

sweep to the normal, non-magrrified condition.
Calibrated voltage measurements,

15.

calibrated

urements and operation with Z-axis

to be triggered

position

if the

wave.

to obtain a

any

the

point,

point

sweep,

that

such

starting

(PULL

desired number

for

viewing

only

is displayed.

waveforms

LEVEL

the

most

sweep

which

at

as

control 7.

negative

triggering

sweep

adjusted

of the sync

pulling

outward

to

view the

displays as

time meas-

input are identical

by

the

in

in

to

""o

A. REFERENCE FREOUENCY

a",

B.

PULSES PER

.(1OOO

LEADING
VISIBLE

DIVIDE
LEADING

.BY .TWO

SECOND)

EDGES MAY NOT BE

AT FAST SWEEP

EDGE

OUTPUT

REFERENCE PULSE

OF

I l*ra

."t

l

DIVIDE

C.

TRAILING

.BY .TWO

EDGE

OF

OUTPUT SYNCHRONIZED

REFERENCE

CHANNEL A
WAVEFORM

filii,t?3Hfi

PULSE

TRAIN

RATES

SYNCHRONIZED

PULSE

Fig. 7. Waveforms

TO

TO

WAVEFORM

A

HEIGHT

in

divide-by-two

@

@

o
o

WAVEFORM

B

HEIGHT

circuit.

l mS/cm

SLOPE+

INT

WAVEFORM

B

WAVEFORM

A

l3

previously

those

to
Either the

Channel

controls can be

described

or Channel

A

used as

required

the horizontal sweep controls

amplitude or

either

done
the DUAL
reverting

positions

CH B

DUAL.TRACE

time

interval

using the

by

position of the

to

single-trace

the

of

dual display

operation,

MODE switch.

APPLICATIONS

INTRODUCTION

most obvious and

The
the dual-trace oscilloscope
viewing
or
voltage,
"Cause
circuit
tions of
detail

simultaneously

phase-related,

such as in

and Effect"

desigrer

or

the dual-trace

to familiarize the

or
digitd circuitry.

the

of this oscilloscope.

FREQUENCY

Fig. 7
divide-by-two
"clock"

outputs

the settings

waveforms. In addition

these
the TRIGGERING
A and Channel
required

waveform levels

7, the

waveform may be

B
In Fig. 7C
the case

DTVIDER

illustrates the

circuit.

pulse

train. Fig. B and

of the divide-by-two circuitry.

of specific

LEVEL control,

vertical

B

produce

to

suitable

the divide-by-two

where the output circuitry

going waveform. ln this case,

shifted

frequency

pulse

with respect

pulse

width.

by a

yet

is that it

waveforms that are

twc

that have

waveforms

repairman. Several

oscilloscope

further in the basic operation

user

WAVEFORMS

waveforms

Fig. A

oscilloscope

to these

position

displays. ln

of

2 cm

either that

output

to the leading

time interval

for single-trace

Bvertical

in conjunction

to obtain

measurements.

operation.

adjustment

with

required

the

can be

This

facilities such

MODE

switch

using the CH

the most useful

the

has

or

feature of

capability

A or

for

frequency-

a common synchronizing

Simultaneous

is an invaluable aid

viewing of

possible

to the

applica-

will be reviewed in

involved in a basic

indicates the

Fig. C indicate the

reference or

possible

Fig. 7 also indicates

controls for viewing

basic control settings,

well

as

controls

the

as

Channel

should be set as

the drawing of Fig.

are indicated.

The

Channel

indicated in Fig. TBor 7C.

waveform is shown

responds to a negative-

the output

waveform is

edge of the reference

corresponding

to the

by

for

as

In an application where

at or near its maximum

rise time effects of

propagation

time
circuit and
possible

must

time delay which may
frequency divider
loscope the input

the consecutive

delay which

be

compensated

circuit. By use of the dual-trace oscil-

and output waveforms can
imposed to determine
delay that

any circuit with

in
procedures given

occurs. Sigrificant

several consecutive stages. Using the

for
be alculated. A more
if the Tp

may

This
also may
waveform

portion

done by

be

be

at a

of

the

possible

faster

sweep

the

logic circuitry

frequency,

desigrr

can

be

the

produce

stages

sigrificant in a critical

for. Fig.

be introduced into a

the exact amount of

propagation

delay may occur

calibrated time measurement,

precise

measurement

waveform

pulling

to view the

is expanded

PULL

the

5X MAG

desired

speed.

DIGITAL CIRCI.IIT TIME REL,dTIONSHIPS

A dual-trace oscilloscope is a necessity
manufacturing
oscilloscope

between

and servicrng digital

permits

easy

two waveforms.

comparison of time relationships

In digital equipment it is
of

circuits
relationship to
frequency

often time-related

are

to be synchronized, or to have

each other.

dividers

previously

as

in many other
dynamic state, some of the
upon the
digital

circuit
waveform measurements
ing Fig. l0
each of these
individual

or mode of

input

and identifies

are appropriate. The

the normal waveforms to

shows

points

and

waveforms have limited value unles their timing

operation.

equipment.

common

Many

for

of the

described, but waveforms

combinations. In the

waveforms
several

change,

Fig.

9 shows a typical

of the

their timing relationships.

relationship to one or more of the other
known
comparison
would
No.
Channel B, although other
desired. Waveforms
be displayed on
8

to be correct. The dual-trace oscilloscope

to

be made. In

typical fastrion,

be displayed on Channel A and

8 and

No.

10,

would

be successively displayed on

timing

through No.

relationship

or

No.4

on

Channel A.

No. 1l

Channel B in

waveform

comparisons may

13

to

operating

is

accumulated

a built-in

8C indicates the

be super-

propagation

Tp can

can be obtained

horizontally.

control. It

portion

of

the

in designing,

A dual-trace

a large number

a

specific time

circuits are

depending

points

at which

accornpany-

be expected at

The

waveforms is

waveform

No. 3

this

allows

No. 4 thru

be

would probably

waveform

No.

rtftra{l trttu!(y

(

r.o,^G',oN

":,"

rut*

"

r@

rr^N

1

tuLsf 5

.". .' t6a, c,rc!,,

Fig.8. Waveforms in divide-by+ight circuit.

DIVIDEBY.EIGHT

Fig. 8 indicates
divide-byeigfit
identical

8A is supplied

Fig.
divide-by+ight

indicates the

B

Fig.

pulses

input

circuit. The

to those used in

output is applied

the output

and

CIRCUIT

waveform

to the Channel

ideal . time

WAVEFORMS

relationships

oscilloscope settings

basic

Fig. 7. The

to the Channel

relationship between

pulse.

reference

t4

.te

stcfro l

for a basic

frequency of

A input, and

are
the

B input.

the

ln the family

waveform No.

10,
for

viewing all of the waveforms;
pulse per
waveform
desirabie" With external
displayed
Waveforms No.
source because they do not

of the

start

waveforms

entire
there

are

portion

of the waveforms would
cases, it is
while the

of time-related

No.

8 or

frame,

For convenience,

No. 8 or No. l0 as the sync

sync,

without

readjustment of the

4 thru No. 7

contain

frame.

would not

It

as shown in Fig. i0 in all

many times when

recommended

sweep speed

that the

or 5X magnification

expand the waveform display.

GATED RINGING CIRCUIT

The circuit

demonstrate the

oscilloscope is

and waveforms of Fig. I I are shown to

type of

effective

circuit

both in desip and

waveforms

is an excellent

l0

there

shown in Fig.

sync source

is but one triggering

external

sync

source

may

any of the waveforms may

sync controls.

not be used as the

should

be

a closer

a triggering

necessary to

appropriate.

be

sync

pulse

view

In fact,

cases.

examination

In such

remain unchanged

be used to

in which the

dual-trace

troubleshooting

using

be
be

sync

at the

the

of a

3rtliJ3uons.
ije:.i::al

'*r\:'iorm
;:ieiorms
:eierence
srmal

!o those of Fig. 7.

and is applied

are sampled

waveform

be

can

D

COOE

SS

AO OR€

ATA

O

INPUT

(

5 - Erls)

The basic

oscilloscope control settings

Waveform A is

to

Channel

at Channel B

of

Channel

A. The

examined more closely

the reference

are

A input. All

and compared

frequency

other

the

to

burst

either by increasing

SECURITY

glr

I

SECURI?Y

Etf

2

the sweep
or bv

timei

time

puiline
'maeniiication"

oui on

desired to- center
oscilloscope

screen.

per

centimeter

the

This

the desired

mSEC

to

<>POSITION

control

'5-

can

waveform

peJ

centimeter

control

then be

to

rotated

information

obtain

on the

5

as

cooEo

tuicTtoi

oA

IXPUI

(t-6rrs)

IART

S
ItrPUT

LIiE ORIVEi

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TA

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PLEXER

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t-

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L_

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45678

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sE cuRl

3

alT

t3

DA'^ SELECI LIiE-O

(E)

Fig.

Typical digital circuit

9.

using several time-related waveforms.

l5

urre

{

orres:recrr'

$

oerestrtcrc'

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srlrcr

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DATA

SILECT

7

DATA

FIIE

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a

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13r

DELAY

used to
lines
can F used
and the
repetitive
the displays.
b9
addition
inheren_t

tion
waveform
loscope

Tput

display.
and
output terminations

-

found

oscilloscope

LINETESTS

The

dual-trace

determine

as well

the delay

as ultrasonic

to-trigger

delay

line

pulse

type

The interval

compared

-large

to determining

in

the delay

of the

delayed

display.

settings

and. output

Any

evaluated.

A common

as well

waveforrns

pulse

The

application

in color television.

settings

output

O'

-

l-

I

tl
tl

rl

SEClrnlrY

I

illa

Fig.

feature

or

synchronize

will

Family

10.

of the

times

of transmission

type

delay lines.

can

be observed

make

it

between

to

the delay

line
pulse

Fig.

12

stretching

results

time

delay

time,

can be

observed

demonstrates

as

the

basic

are

shown

and ripple

of moAfying

can be observed

of

the

receivers.

and

typical

I

I

rl
ll

I

----.1

aT I

F-

of

time-related waveforms from

oscilloscope

The

the

Channel

on

possible

to

iepetitive

io

be ini,estigated.

pulse

the

determinid

on

the

the

test

circuit.

on the

can

the

directly.

delay

line

Fie.

circuil

t:

connections

olll|o

atls,

$CURtry
OA'ABIT 2 OATA

can also

type

inpirt

S€CURtty

be
delay
pulsir

A diiplay

Channel

b.

A

synchronize

pulses

should

In

dfstortion

by examina-

Channel

typical

oscil-

Typical

oscillosiope

be observid

input

and

checks

is

shows the

to

----rl

3IT 3

ON€
TRANSMISSION

check

section.
compared
the

delay
determining
waveform
lrom

output

STEREO

B

is in
ampliliers
or
efficiently
identical.
side-by-side
progessively
amplifiers.
been
repair-methods
immediatelv.

!

COTPL€TT

FRATI

typical

the

"{" delay

The

input

for

composite

is

approximately

the-delay

revpals

an impedance

resulting

AMPLIFIER

Another

t-roubleshooting

are used

otherwise

used

sigral

comparison

When

located,

digital

circuit in

lin-e employed

waveform

delay

time,

video

signal for

characteristics

any distortion

mismatch

from

an open

SERVICING

convenient

stereo

and

the

abnormal,

to

localize

applied

to

sampling

the

defective

the

effects

are employed

Fig.

and the

using the

one

microsecond.

line.

use for

dual-channel

amplifiers.

output

the

dual-trace

the

the

inputs

of

both

identical

or

of whatever

can

be observed

9.

in the

video

output

line,

may

geatly

waveforh

sync

The

In

addition

the

be

introduied

attenuated

horizohtal

reference.

of the

that

or

a

oscilloscopes

If

identical

of

one is

weak,

oscilloscope

defective

rmits

signal

of

both

can

state. \t4th

amplifiers,

Ue

points

malfunctioning

troublesh6otiri'g

and anal--yzed

amplifier

are

pulse

indicated

output

channel

distorted

can

be
an

-maOe

6v

in

botir

stage has

and

of
to

a

l6

cllt0 lilGtrc

.10

0

il0

_lll]ffi__

0

-------ljilu

-10

+2

__J

0

-7

Fig.

CHANNEL

A

(INPUT

PULSE)

CHANNEL

B

(OUTPUT

PU

LSE)

Gllrc

lllfliftfi

lllllllllr+llilllilrr-liilli

|IXUUU

Gilto ttfou$ct

t,

ll$-------uxu{[-----]1lu

t, ltP(|fttD

Il il till_____J il fl ll t] ___,1 fl fl fl tl

UUUll|l

I l.

Gated

cllcltT

tfttfotl

__Jllllttft

IJJU]}U

ouTtul

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tuts]

(?ouillt

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ringing

circuit

3oH@

rnnltD)

and waveform.

o

o

o
o

o

o--@

o

/lnffiR_

UJ]JU{

uu

VIDEO EQUIPMENT

Many of the
performed
later
tions. One of
interval test
effectively
the

single-trace applications
and 21. the information
vertical
detail in Fig.
synchronized to.
the Field
onto
operation,
can be viewed
indicates

alternate VITS.

1. The video equipment from

2. T\e control
obtain

With

3.
connect

detector test

4.

Set
a. If the

b. If the sync

5.

Adjust
fields

6. Connect
detector

7.

Set the MODE

waveform

Channels

8. Set the

position.
sweep speed.
the right
displays.
app€ar
t-l.rere
displqr
complete
field
B display.

using single-trace operation.

in the applications

these

sigral), can be accomplished much more

using a dual-trace oscilloscope.

blanking interval

20. Also, because the oscilloscope
and

#l

each otheras

the signal information on each

the sscilloscope

tion is
mitting

to be
a color broadcast.

a 2-field vertical

the

oscilloscope

the Channel

the

SYNC switch

sync

video

position.

switch

VIDEO(-)

the

the SWEEP

are displayed

the
test

A and

SWEEP

This expands

hand

The waveform

as shown

provision

is no

to either

vertical frame,

display will

SERVICING

video

s€ction covering single-trace

procedures,

on the Field

pulse

the vertical blanking interval waveform,

Field

*2

shown in Fig. 72, With

separately without overlapping.

yiewed

settinp of Fig.

point.

signal

Channel

point.

displays

the VITS

must

display

and television

A

as follows:

and blanking

are

and blanking

switch

TIME/CM

on the

probe

B

switch

to the

should now

B.

TIME/CM

portion

in the

for

of the

appear

servicing

section and as shown in Fig.

is different. This is

waveforms

control setting for viewing

probe (set

positive,

position.

oscilloscope

the display

information

of the expand6d

information

drawing of

synchronizing

two

it

on the

procedures

are outlined

These

viewing the VITS

#l and Field 1t2

are

which

the

set to

be

14 are those

on Channel

pulses

control so that 2 vertical

(set

DUAL

control

fields which

cannot

a station trany

receiver

at l0:l) to the

pulses

of the

use

the VIDEO(+)

are negative,

screen.

to l0:l) to

position.Identical

be obtained

to

by

will

bn each

Fig.

the oscilloscope

predicted-which

be

Channd

(ve;tical

outlined in

As

shown in

sweep is

superimposed

dual-trace

blanking

Fig.

VITS

informa-

required

A.

operating,

observed

the video

the.lms/CM

increasing

appear

toward
waveform
trace'may

21.

Becatrse

comprise-

A

or Channel

can

opera-

video

be

20

pulse

14

the

to

I

use

on

the

a

5000
l&Sec

PPs

PULSE

Fig. 12.

WIDTH

Delay

ULTRA SONIC

DELAY

LINE

(

5,l Sec)

line measurement

OUTPUT

.

9. Pull

the
tional
counterclockwise
left
shown

Because

sweep

the

5X

until

in Fig.

speed

sigral

<>POS

of

displays

control outward

magnification.

the

direction

expanded

15.

NOTE

the

low repetition

combination,

will

be reduced.

Rotate

moving

VITS

the

to obtain

the

control

the

information

rate

brightness

traces

and

appears

the

high

level of

an

to the

addi­in

as

l7

a

:-

DELAY

lsS

(INPUT)

A

ci

(OUTPUT}

B

CH

@3

FIER.

HORIZONTAL

TO

NO

NOTE:
NECTION;PLACE

INSULATION
LEAD
IMITY OF
LIFIER

IN CLOSE

OR

TUBE.

AMPLI

ELECTRICAL

CLIP

PLATE CAP

OF

HORIZONTAL

PROX.

CON-

ON

AMP-

VI

DEO

AMPLI

the Channel

Once

10.
identified

as
information,
sigrr4l-tracing

probe

should

that the sync

insure
sync

is interrupted,

sigral
reverse because,
provision
two vertical

in the

fields

Fig. l5 shows

and Field#

#l

is displayed

tion

VITS information.

on the bottom

SINGLE.TRACE

INTRODUCTION

ln addition

are, of course,

outlined,

applications
oiiilloscope
oscilloscope,

there

where only' single-trace

required. After

ii

the

FI ER

Fig. 13.

Channel

A and

being

the Channel

trgubleshooting,

and

left at

be

as

oscilloscope

Field

either

B

probe

the video

sigral

waveform displays

the

not hterrupted.

is

previously explained,

to

which comprise

the dual-trace

presentation of the Field

trace.

APPLICATIONS

to the dual-trace

many service

gaining

will be able

user

to make the

BOTH

SET

iO:l ATTENUATION

OELAY L INE

*NOTE:

ATTENUATORS
SAME,
DEPENDI

Checking

displays

B

or Field

#l

have been

may be used

the Channel

and

detector

test

there is

identify either

a complete

The Field

applications

#1

previously

and laboratory

operation

experience

judgment

PROBES

FOR

SETTING

MAY

BUT

NG ON

"Y" delay

VITS

#2

for

A

point to

If the

may

no

of the

frame.

informa-

of the

with the

as

VERTICAL

OF

SHOULD

VARY WIDELY,

CIRCUIT

line

BE THE
TYPE.

in

color

whether a

to

the single-trace

using
The following

is adequate.

tion
alternate
described

VIDEO

A triggered sweep
servicing
also includes
make

features

These

r

r
o

television receivers'

job

can be

performed more

or the dual-trace

are applications

In several

the dual-trace

method

using

for the same application.

EQUIPMENT

SERVICING

oscilloscope

aligning

and

several

video servicing

video equipment.

features that were

easier and more

include:

SWEEP

vertical

viewing
speeds

Vector
Wide bandwidth

TIME/CM
sync at

sweep

frames and

appropriate

for viewing

overlay for color

for high

pulse presentation.

VIDEO

TO

OUTPUT

AMPLIFIER

method

which single-trace

in

will be

it

cases,

application

is

control

automatically

speeds

horizontal sync

lines.

demodulator

resolution

efficiently

operation.

of

by

opera'

found

that

an

has been

advantageous

in

This oscilloscope

incorporated

to

comprehensive.

selects

appropriate

for

at sweep

checks.

and

video

l8

VI

DEO

VERTICAL

SYNC

PU

LSE

VERTICAL
BLANKI

TELEVISION SET

NG

[@ t

0

$@.'

@

2mS/cm

o

eE

{D,

I

l

I

l

Fig.

SIGNALTRACING
VOLTAGE READINGS

television receivers
ment for
instrument. It
presence
may
the
path, a point
When

Oscilloscope

15.
VITS

information.

AND

general

For

be used to trace a

signal

this happens, the

troubleshooting and isolation

(or

that matter), the oscilloscope is an indispensable

provides

of normal

path.

signals.

As measurements

may

be

Fig.

14. Set-up for viewing fields I

presentation

PEAK.TO.PEAK

almost any

a visual display of absence

sigral

found where the

source

of fields I and 2 of

other

electronic

This method

by measuring

proceed

of trouble has

several

sigral disappears.

of troubles

(sigrral-tracing)

along the

been located.

equip-

points

sigral

in

or

in

and 2 of

mere
peak

performance
peak
accompanying
usually
pictures
peak-to-peak
readings
waveform pictures.
followed

until the

The

ments
MEASUREMENT

COMPOSITE

servicing is

signal, the blanking pedestals

and 17

composite video

pulses

can be observed

to
Knowledge of waveform
normal

waveforms help

problems.

television receiver

VITS

information.

.However,

presence

voltage measurement

voltage

procedures

are

Probably the most important

and vertical

determine whether

the

oscilloscope

or

absence of

cln often

measurements.

service data on the equipment
includes waveform
include the required

voltage.

on the

by additional

trouble

show

waveform,

The

oscilloscope

is isolated to as

for

given

earlier

paragraph.

VIDEO

the composite waveform

typical

sigrals

blanking

at various

the

technician

of the

located

be

Compare the

Any abnormal

readings

making

and the

known

peak-to-peak

in the

WAVEFORM

oscilloscope

synchronized with

pulses.

stages

circuits

makeup.

technician

should

to

shows much

sigral.

The schematic

pictures.
sweep time

with those

CALIBRATED

and the

causes

be in

provides

lt

signal. The cause of

by making

These waveform

and

peak-to-peak

shown on

readings

in the

small an area

are

locate

study

suspected circuits

voltage

ANALYSIS

waveform

consisting

sync

traces

when

horizontal

Composite

of

the television
performing
ihe

appeaiance

of various

and

such waveforms

good

operating

more than the

peak-to-

a

poor

peak-to-

such

diagam or

being

serviced

the normal

voltage

the

should be

possible.

as

measure-

VOLTAGE

video

in

of the

pulses.

correct

Fig.

observing

video

receiver

normally.

abnormal

video

sync

signals

of

many

in a

con-

l6

'a

l9

HORIZONTAL

PULSE

SYNC

HORIZONTAL

BLANKING

PULSE

pofl

@[@?op

CHA

1

0p

S/cm

VIDEO_

INT

Fig.

16. Set-up

VIOEO

DETECTOR

for viewing

horizontal

lines

of composite

3@[@fl

@

CI

o

videq

@

PI

CTU

TUBE

signal.

RE

VIDEO+ or

(See

text)

INT

-

20

Fig.

17. Set-up

VIOEO

OETECTOR

for viewing vertical

fields

of

composite

video

sigral.

'1

dition,

noting the waveform

various

at

points

amplifier.

To set up the oscilloscope

waveforms,

use the following

l. Tune the television set to a

2. Set the MODE switch to the CH A

3.

4.

5.

6.

the

Set

SWEEP TIME/CM
position for
mS/cm

Set
Set the

Pull

position

the

SyNC
SOURCE

the TRIGGEzuNG

observing

for

observing

switch

switch

for viewing conposite video

procedure:

local

channel.

position.

switch

to the

horizontal lines

vertical frames.

INT

position.

position.

to the

to the

VIDEO+

LEVEL control

sync,

7.

the

Set

8.

Connect a

CH A DC-GND-AC switch

probe
Connect the-gound clip
set chassis.

With the

connect the tip

cable

of

to the CH A INPUT

of the

probe

probe

the

set

to the

probe

for

the video

to

output of the television set.

9. Set
defleetion

the

CH A

possible

VOLTS/CM

without

switch

going

for the largest

off-scale.

10. If necessary, rotate the TRIGGERING
position

to

a

I l. If the

sync and blanking
signals are
VIDEO+

position;

negative, use

12. Push in the
position

to

a

Adjust the

13.

desired brightness and best

14. To

view

a specific

color burst,

for 5X

rigltt

magrification. Rotate

to select the desired

provides

that

pulses

positive,

set the SYNC srvitch

if the sync and blanking

the VIDEO-

TRIGGERING

provides

that

INTENSITY

and FOCUS controls for the

portion

pull

outward on

a synchronized display.

of the displayed video

position.

L:'YEL control and

well-synchronized

a

focus.

the waveform,

of

the

<>POSITION control

the

portion

same control

of the waveform to

be viewed.

15. Composite video

points

on the video circuits by
points

those
of the

as required to

scale, and by

setting

waveforms may be checked at other

moving the

and

changing

keep the

the VOLTS/CM

display

readjusting

the

LEVEL control to maintain stabilization. The

the observed waveform may

of
moving from one monitoring
fore,

it

may

be necessary to reverse the

be

point

SYNC.

in the video

l0

sS/cm

to the

or

for

automatic

position.

AC

2

1ack.

to the

television

l0:l attenuation,

detector

vertical

LEVEL

control

to the

pulses

are

rotate

display.

as the

such

left or

probe

tip

to

control

within the

limits

TRIGGERING

polarity

reversed when

to another; there-

polarity

of the

roRr

CIRCUIT

F€CI

OE

IORNL

CIRCUIT

Loss r
f Rt

X€Y

QUt

Rt sPoNst

trctsSlvt 8t(*i
fRtQUticY

i0N-

sPoNst

,

MST

!INTAR
SHIFT

LO5S C Lfr

FRT

XCY

QUT

RtsPorst

Fig.

zoNTAr

PULSE

)r

sroR

A

xlcli

,r\

Rt-

r'1

tl

It

18. Analysis

NORMAL

SYNC PULSE

SYNC

COMPRESS

PULSE

ION

CAUSED-BY

IMITING

L

rrwHITEI

Fig.

N

19.

SA T URAT IO

CAUSED B Y

LIMITING

OVERALL

FREQU€NCY

r lol/

of

Sync pulse

sync

RECEIVER

R€

SPONST

I

rtit
8LA((
SrRtATI0rS F0t-

LryIiG A sflRP
ch^r6t
TURI

c#ict
OIiG

PICTURI
sr{Att0
I

pulse

distortion.

waveforrns.

€FFECT

PICTURE

PtcluR(
Nmnt

L0ss 0f

TUET

vtRr

C

5U0l|c

f

Uet

IA

OT

lcat

qllt

li

Ii su-

URGT

ARTAS;

Ptc-

Oil

PIc-

PIc-

I L

PULSE

SYIIC

The

evaluated

be
horizontal

pulse

sync
bandpass

ANALYSIS

IF amplifier response of a television

to some extent by careful observation

pulse

sync

waveform

characteristics. Some
and their relation to
Fig.

18. Sync
positive
shown in

or

pulse

negative limiting in IF

Fig.

19.

receiver

waveform. The appearance

is affected by the IF

typical waveform

IF amplifier

waveform

response

are indicated

distortions

produced

overload conditions are

can

of the

of the

amplifier

symptoms

in

by

(VERTTCAL

11TS

Most

network

(the

signal

VITS)
troubleshooting
localize
and

trouble

shows when
ing procedures
scope

displays

The
interval.
white

line

of the VITS.

VITS
On the

above

TNTERVAL

television

that

and

servicing

to the

antenna,

realigrment

show how

is

transmitted

television

the

top

signals

can be

television

may

to

analyze

during

set, it

of the

TEST

STGNAL)

contain

a very

sets. This VITS

tuner,

lF or video

be required.

and interpret

the

can

be

picture,

a built-in

valuable

The follow-

vertical

seen

as a

when

the

test

tool

in

can

sections

oscillo-

blanking

brighi

vertiial

2l

linearity or height is adjusted to view the vertical blanking
interval
the blanking

(on

TV sets

circuit

with internal retrace blanking

must be disabled to see the

VITS).

circuits,

tire VITS appears at

just

and

before

the first line of

the bottom of the

video.

vertical

blanking

pulse

.

|

lTllltl

-,|-

Fig. 20.

''i'."'i',..'i'

ruLI I,EURIT

\

Typical VITS signal,

rlit.sQuet0

(tY

Et

/ilNory

fields I

tuL5t

lNTtRCnANCt0)

ruL

't

*r'r

I

I

30e

ll SLAi(lNG
Pt

and

,,o,

!IA!

0t

2.

Each
equal amplitude. By
of these frequencies
the television

the multi-burst frequencies is transmitted at

of

receiver,

observing

after

the

the comparative arnplitudes

the

signal is

processed

frequency response of the set is

through

checked.

up the oscilloscope

Set
Connect the

^

1.
the video detector
video section

If the

2.

CH A

of the

television set

circuit, bypass this

the MODE

3. Set

4. Set up

switch to CH A.

the oscilloscope
waveform analysis as
frames will

Reduce sweep

be

visible.

time
ms/cM) with the
expands the dispiay
VITS information will
expanded

Further expand the

6.

(pull
the
ion,

waveform

outward on the <>POSITION

<>POSITION

moving

the trace

follows

as

probe (set

other

or

to view the

at l0:1) to the

desired

test

VITS:

output

point

of

in the

television set.

has

ve{tical retrace blanking

a

during

circuit

previously

to

millisecond

.1

the measurement.

vertical

tbr

cornposite

described. Two vertical

per

centimeter

vicleo

(.1

swEEP TIME/CM switch. This

by increasing the

sweep

speed. The

appear to ihe right on the

display.

with

sweep

the 5X magrification

control). Rotate

control in a counterclockwise direct-

the

to

left, until the expanded

VITS appears.

WHITE

FIELO

J

wx,t€

U

8LAcx1

aoRrz

SYNC

Fig. 21. Vertical

another, but is
amplitude,
sion networks use the
checking of
can use them to evaluate television set
line of Field f I
followed
MHz, 3 MH43.6 MHz,
quence
ol Field
multi-burst
valuable

fl2
window pulse

progressively
have less value

screen.

followed

mation.

The

transmitted VITS may

and

network

by sine

of frequencies

(line

#2

portion

to the technician.

(lines

l8

and

Field

by line

*2

IZING

blanking

a

waveshape

(line

wave frequencies of

279) may contain an identical multi-burst. This

280), which may contain
and the staircase of

lighter

to the technician.

is interlaced with Field

#l

279

interval, shorving typical VITS

precision

precision

transmission equipment, but the technician

17) may begin with a "flag"
(3.58

is

called the

of

VITS is the

the

shading,

line l8 is followed

and

vary

sequence of specific frequency,

similar to

The

Fig. 20

signals for adjustment

MHz)

"multi-burst." The

portion

second

are valuable

As

from one

performance.

MHz,

0.5

4.2 MHz.

and

line of

the sine-squared

3.58
to the

seen on the television

#2 so that line

by line 280. The

channel to

21. The

and

white

of

1.5 MHz, 2

that can be

I

Field

#

MHz

network,

televi-

The first

video,

This se-

first line

and

bursts at

infor-

and

most

Field

pulse,

but

17

is

en-

NOTE

The brightness level of the
reduced because, although
only 60 Hz

speed is

(a

pSEC/cm

20

16,000

signal display

repetition rate

the

pSEC

period)

(.1

mSEC/cm magrified

times).
The waveform

7.

should

be

similar

to

22. For the oscilloscope display, each
pulse

starts a

(multi-burst)

279

Fig.22. Oscilloscope

single-trace

new

sweep. This causes line 17 and line

to

be superimposed, as are lines 18

presentation

of

operation.

will

the writing

that shown

vertical sync

VITS

information,

be

is

five

in Fig.

aa

280. The

and
reinforces

ideniical

multi-burst

the trace. However, lines

and

both sigrals are superimposed

other.

8.

presentation

The

is the limit

of observation

oscilloscope.

preceding paragraphs (Fig.22')

the

of

With

the Model I4'76

however, a single-field

This

With

the Model 1416

the

causes

Channel B information

oscilloscope.
position.

displayed on alternate sweeps, as
Field

preselecting

Field
multi-burst
valuable
because
VITS,

VITS. Because

#2
#1

Field

or

Field

#1

or

#2

Field

information

for

troubleshooting television

present

it

is

either

can be used for troubleshooting

on

both

tracing.

Now

to
muiti-burst
not

be equally
response
good

color television

the

multi-burst
attenuation
reference
for

reference).

u.a,lyze the waveform.

are transmitted

coupled through

curve. Fig.

23

shows

receiver, identifying

and

for

voltage

showing the

each.

Remember

(the

2.0 MHz modulation

at

sigrals are identical,

l8 and

280 are not

over each

possible

with a single-trace

oscilloscope,

presentation

VITS

oscilloscope,

are Field

there is no

#2

(Fig.

15)

in the VITS is

brovision

infoniration,

will appear. The

the most

receivers

Field

#l

and

and

the same

the

that

level,

the

receiver

but

due to its

desired response

each

allowable

-

fiequency

dB equals

6

amount

frequencies

All

shbuld

which

can

to

#l

either

Field

signal

of the

should

for

half

be used

be
be

and

for

and,

*2'

of
of

the

chance

response
video detector
the

on
shows the VITS
except
bursts on either

into the

below
channel

reasoning

If the
channels,

misadjusted,
traps
or faulty.

for
Iook for
bridges

a

.of

the

antenna

on

some

channels.

on

all

IF

amplifier

As

another

the

bench with

that

the burst

passband,

picture

ihe

carrying

is right,

poor

maybe

at the input

response

causing

channels, the trouble

stages.

example,

very

a

at the

video detector

at 2.0 MHz

side.

This suggests

chopping

carrier frequency.

VITS.

If the

and the

at 2 MHz

an FM

a bite

of the

If the VITS response

all channels,

the

trouble will

open peaking

across foil patterns,

system

causing "holes" or

If the VITS is

let

us assume

poor

picture.

to be about

low

is

an IF trap

frequencies

out

Switch

same thing

IF amplifier

trap

requires

is

not

at the

on only one

set

could similarly

at

ihe detector

be

in the

coils, off-va_lue

etc.

GRATICU

LE

abnormal

is

that we have

at

probablv

a set

Our oscilloscope

normal

tilted

compared

to

is detuned

about

2 MHz

to

is

another

seen, then

realignment.

seen

on other

tuner

input

channel,

-Other

be misadjusted

output

is

video

normal

amplifier.

resistors,

-solder

the

in

the

our

is

5

+

o

.D
!Jo

I
lrJ
vt

z
o

Soo

lrl
G

4t

To locaiize

video

detector. This

before

or after the

the

detector,
channels
tuner or

t7

(l

z

-j

I

l-36-MH,

MODULATION

I

4.2-MAz

MOOUL ATION

25

\l

IJ

t/

42

FREQUENCY-MHz

Fig.

23.

Color TV IF

trouble,

will localize

detector. If the

check the VITS

look okay

antenna-system

but

:J-

2

o-MH

l'oJ"o'

Ll.o-ux.

MODULATION

43

start

others

troubles.

a?

o

Ptcrune

CARRT€

I

t

o

5-MH:_

A

M

TION

ODUL

44

amplifier response

by

observing

on other

do

45

trouble

to a

multi-burst

channels.

you

not,

Don't

the VITS

point
is normal

probably

overlook

R

\

46 47

curve.

at the
either

If

some

have

the

cro

-

--

VECTO

OVE

Fig.24.

VECTORSCOPE

Performance
circuits in
the vectorscope
tional

equipment

B &

K-hecision

\

\

this.

First
scope

Attach

1.

must

overlay

2. Connect the
and tune in

3.

Adjust

Installation

OPERATION

testing

and

color television

operation

needed

color bar

the horizontal

generators

and

be equalized (see

vector

overlay to scope. Remove bezel,

and re-attach bezel

color bar

the

color bar

television

the

set's

of vector

receivers

of the oscillosiope.

is

a color

vertical

Fig.

generator

pattern.

hue

R

RLAY

overlay.

adjustment

is

simplified
bar

are

gain

25).

(see

Fig.

to the

and brilliance

--€o

of

the
The

generator.

ideally

suited for

of the

24).
television

controls

SC R EWs

color

by using

addil

The

oscillo-

insert

set

to

mid-range.

4.

at

Set SWEEP

5.

Connect

jacks.

the horizontal
driven element
cathode is the
cathode.
the

output

6. Adjust the
gain)
pattern
oscilloscope

TIME/CM control

probe

cables to the

Channel A is

input.

of the red

driven element,

(The

driven element

signal of the

CH A

VOLTS/CM

that

approximately

is now

to the CH

CH A and

the vertical input

Connect both

gun,

usually the

then

is the element

color amplifier is

(vertical gain)

and

controls to obtain

set up for

fills the

vector overlay.

vectorscope

position.

B

IMUT

CH B

and

Channel B

probe

tips to the

grid.

connect

If the

to the

to which

applied.)

(horizontal

CH B
a compressed

45"

The

operation.

is

23

R.Y

I /

WI

1

j

,v

(R-YI

'\l

-

450

t\

B-Y

.

90"

| 050

I

@

'@!

o

Irl@

A lo- @

vector

For

7.

probe to the driven
vector
television
displays
syslems

If
will appear
rotate'the

on the

is
with the

The

measurement

a color

in
iarize
produced
ihat

the

of

control

their

elliptical

presentation, merely

pattern is the same

set

obtained

with either

picture

the

vector overliy

rigfit side.

vector
vector display

TV set.

himself with

by

the color

petals
changes

ahplitude.

pattern

element

manufacturer.

for sets

grid

drive

NOTE

tube uses

on the

right
The color

overlay.

the functions

of

The serviceman

the effect

the

amplitude

but

controls.

color

not their

position^of

the

lastly, 105" sets

than 90"

Fig.

of the blue

using 105"

or

cathode

sidq

180" so

provides a very

control

sets.

Equalizing hor2ontal and vertical

25.
scope operation.

the horizontal

move

gun.

given

as

type

Fig. 26 shows

systems

cathode

of the screen.
bars

of

He

position.

the

drive.

the burst

drive,

the BURST

will then aligr

the demodulators

should

on the

should observe

vary the size

will

petals

will have a

The table below

The color

by

typical

and 9O"

Just

label

quick
famil'

pattern

The hue

but not

more

thg

ADJUST

REOUIRED

li3ts

pattem.

range of tlte color set's
posible
axis.
petal
CHROMA reference
oscillator
tors.

is
position.

on
are aligred
general

vector display
aligrment.
procedure
counting
between

A

gain

some

The vector display can be used

At

should be

A

slight touch-up

necessary to bring

the chroma bandpass

be aligred

If the

Vector-

for

common

to

rotate the

the center

is transformer-coupled

Do not attempt

set has adjustable

to locate

bars simply adjust

R-Y

troubles and

hue

petal

R-Y

of the

vertical.

by a

sweep

by

can

Follow the manufacturer's

BY.

and

If

oscillator.

of this

R-Y

the

to make any adjustments

amplifiers.

generator

just

vector display.

a

also be

the

used for demodulator

proper

their effect

to

control.
hue

it

transformer is all that

for the correct

It should be

about the vertical

control

is not, locate the

In most sets this

to the demodula-

petal

to a vertical

These amplifiers

and cannot

demodulators,

and instead of

coils

the

on

the

check

R-Y

the

the

alignment

angle

in

24

GRID

DRI

R-Y

VE

l*-.--

VECTOR

ID

GR

DRIVE

VECTOB

TROUBLE

Loss
Overloading
Color

weak

Lack

Demodulator

DISPLAYS

of color

amplif

of range

DISPLAY

sync

of

color

iers

unbalanceo

of hue

out

of alignment

FOR

FOR

GENERATOR

amplif

control

PICTURE

90"

B-Y

-r--

1 050

105. PICTURE

coLoR,

BAR

iers

or

TUBE

CATHODE

DRIVE

R-Y

TUBE

EFFECT

Petals
Petals
Flower pattern

R-Y

Angle

ON

pattern

of
are crushed

petal

cannot

vertical

between

petal

not
specification
General

Specif

PATTERN

will

rotate

or flattened

very

elliptical

be

made

to

petal

R-Y

to manufacturer's

(90"

ication

or

and B-y

105.
).

be

G REEN

EFFECT

Varying
Color

distortion

Color

distortion

Hue

control

fleshtones

U/rong

colors

ON

colors

won't

T.V.

PICTURE

adjust

Fig.26.

Vectorscope

operation

and

patterns.

25

,

TELEVISION ALIGNMENT

INTRODUCTION

Alignment of
circuits in
oscilloscope, such
of test
sweep,

equipment

IF sweep and RF sweep, marker

supplies and a

tuners, the

television receivers

as

this instrument. The additional

required are sweep

VTVM.

aligrrment displays a bandpass response

of the

oscilloscope

of the type always
books and in the television set manufacturer's
instructions

75 74 rl
l8 l9

rNZ

JA

rxz}

{75

Fig.27. TV

(typical

40

response curves

response'curves

7i 70
42 4) a4 45

CHANNEL

rxz wr0t

6

I

technique.

The ideal

instruments for television
oscilloscope and the B & K-hecision
tor. The B & K-Precision
all necessary
from
and
precision

For
television
ever,
use

of

ln this

emphasized. Proper

is
equipment reqtrired for
instruction manuals

sweep ranges, markers and DC

one instrument. The

calibrated accuracy of the

alignment.

complete

set,

the following

the

oscilloscope

aligrrment

follow

manual,

the manufacturer's

general

for

only

use ofthe sweep

alignment

for those

video IF

strip, and chroma

required

a

high-quality

pieces

The sweep

generators

generators,

generator

curve on the

for video

DC bias

method

screen

shown in theory

aliglrment

69 5A 67 55 65

47 48

46

4

are shown in F

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CH

tF

obtained by sweep-frequency

aligrrment are this

Sweep/Marker

Genera-

Sweep/Marker Generator provides

bias voltages,

simplified operating

procedure

instrument results

instructions of each

particular

instructions. How-

instructions

set-up

sweep-frequency

proper

the

use of the

should be

demonstrates

alignment.

oscilloscope

generator

provided

and

other

in the

instruments.

of

all

in

NOTE

For

a

comprehensive analysis of television

ment, we recommend the instruction

B&K Model

the
This "handbook
not

only the
but all the how and
aligrment

in
generators,
valuable
make

procedures,

aligrment easier
many illustrations
step approach
textbook. Copies

B & K-Precision

MPORTANCE

The most

of

the

receiver
sweeps
channel
processed
shaped by the

rapid way to determine the

tuner,

IF
provide

is to

through the

at a controlled, repetitive rate. As this

through the

gain
sections. Because the
tuned

circuits to
has
at

bandwidth

proper

the

certain

points

properties

Fig.

27 shows the sweep signal with
curves of the tuner, IF
circuits below it.
to
be obtained

These outlines

scale.

the outputs of the various

if

415 Sweep/Marker

of television alignment"

procedures

for using the

why answers about television

general.

this

Even

comprehensive manual

if

you

insights and tips

more

and

and easy-to-understand

qualify

it as the

are available from

distributor or the factorv.

OF SWEEP ALIGNMENT

and chroma

a

entire

tuned

and bandpass

portions

constant-amplitude signal which

bandwidth of

portions

properfies

signal is channeled

another

it is important that each

charhcteristics. If the

and the envelope observed,

up to that

point

amplifiers and

The

bandwidths

shown are approximately

are similar to

receiver were demodulated and the
oscilloscope.

Because

of the relative

response'is least critical.

Some reference
importance of
frequencies
area

are

is the most
this area will affect the amplitude
response

curve

Notice

that
constant-amplitude
spectrum.
information
circuits
This
Notice
chroma
plitude

Notice

are modified by

of the

is shown by reference to the

that the sigral information

frequency range

with respect to the

the chroma frequency range

frequencies
proper
on the

aiignment. Notice
slope of the IF

are identified

critical because improper

and shape of

and this

in turn affects

the chroma information is located

portion

the transmitted

of

that the relative amplitudes

passing

television receiver tuner

overall

at

(4.08

MHz)

level

signal

(3.08

MHz).
for this frequency-versus-amplitude
overall IF
between
chroma
tuned to
usually 4.08 MHz

27. TTus
characteristic
response

response curve,

the IF output

portion

of the receiver. The

the upper end of the

and

a Chroma

and the

provides

bandpass

chroma frequency range

a response

compensates for the amplitude-versus-frequency

of the

curve.

The

chroma

result

portion

of

cornbining

align-

manual for

Generator.

includes

instrument,

use other

sweep

provides

that will

professional.

The

step-by-

"how

to

align"

your

overall

given

condition
television

television

of the
a

signal is

of the

of

from

receiver,

one series of

it is

the various

section

sigral is demodulated

gain

the

and

can be determiJred.

basic response

chroma bandpass

the

curves that would

sections

curve observed

bandwidths,

of the TV

on an

the tuner

to show the

that

the

response

chroma

curve.

This

IF aligrment

the

color

picture

chroma
quality.

on a

television

of the

through

chroma

the tuned

and IF amplifiers.

IF

response

the

upper end

is reduced

at the

To

characteristic

takeoff

amplifier

chroma takeoff

cuwe.

of the

in am-

end

lower

compensate

of the

coil is used

of the

coil

as shown in Fig.

of the

the

overall IF

response of the

of

in

ii

ti

=
:

is

26

the

of

IF
produce

range
applied
indicated

specified
cedures.
takeoff coil
the bandpass

SWEEP

ing

frequency sigral

bias line

grounding
circuits

to the manufacturer's

receiver
is
problem
strip and
response and the chroma
likely that
response is

and the response

curve

(3.08

to the bandpass

Aligrment of the chroma

ALIGNMENT METHODS

The best method of checking aligrment

which stages require alignment

are then observed

The technician can then

require alignment.

satisfactory but the chroma

overall response

a flat

MlIz to 4.08

the overall

by

as a separate step

In other

performed

is

transformer.

at

must be

AGC line. The outputs

the

between the video

is

the output of the bandpass

the

IF

poor

on the

MHz). The resultant sigtal

amplifier which

chroma

procedures,

tuner antenna

the

clarnped

recommended response curve.

response are

requires touch-up,

slope

chroma

in

response curve.

takeoff coil is sometimes

in manufacturer's

adjustment

together with

by

on an oscilloscope and compared

decide which

For example, if the IF response

response is

detector output of the

affecting chroma

takeoff

the

chroma

has the response

the

is to inject

terminals.

application of bias

of the IF and chroma

amplifier.

poor

particularly

coil is

frequency

then

is

test

of the chroma

adjustment

determin-

and

an RF

sweep

The AGC

portions

not,

then it is most

of the

then

If the IF

if the

response.

to

pro-

of

or

the

IF

portion

RF

The
aligrment
thah
circuit,
attention.
between
pre-alignment procedure
some manufacturers.

mined, an alignment
ed. The aligrment

Some
terminals which can
quencies

done by selecting

One way of doing this
generator

picture

selected and this is
is the

sweep

the

for the aligrment of these

injected at the mixer

aligrment. The IF

then modulated with

before

receiver and the recovered

chroma circuit alignment.

problem

of

that

Once

suggest

VSM, or video

modulation is demodulated at

TV receiver

Other

the

which is located

This is

the tuner and

the deficient

sigrral combinations

in

the

for IF alignment. After this is complete,

carrier

this

frequency for the channel being used is

and applied

manufacturers

is detected

of the tuner

because

IF

section;

part

of the

is

portion

check

procedures

generate

receiver so that

the

right combination

is to first connect an

modulated

sweep

stages.

re'commend

grid (or

picture

a video

at the

passband

the

however, the

on the

the first

given

of that section

by

modulation

to the

base,

carrier

sweep volfage
sweep

seldom

is so

tuner,

tuned matching

IF stage. A separate

for the

the

of

vary

IF and

overall aligrment can be

frequarby

video

receiver

with manufacturers.

the tuner

at

video sweep fre-

of input sigtals.

a video sweep sigral

method). This video

the video detector

chroma

bandpass circuits

IF'sweep frequency

an

if transistorizpd) for IF

(VSM

detector of the TV

voltage

creates

greater

much

mixer output

may require

network

link

circuits

is deter-

perform-

can be

antenna

RF

sweep

the

(this

MHz)

@5.75

again). As

is ueed for the

an

by

of

is

ANTENNA

TERMINALS

SELECTOR

562

,'A";'

*\-/^5

ara-

SWEEP/MARKER

GENERATOR

SWEEP

RF

VOLTAGE

OUT

TELEVISION SET

Eig.28.

Typical

.O1V/cm

tuner alignment

A DJUST

HORIZONTAL

sl zE

s€t'up.

o-l

f-r-

e

@

27

Another
chroma
sweep modulation of the IF
used to
of IF

alignment and

of

the

final

overall

ln conjunction with IF
manufacturers
spot frequencies

point).

test
tuned

circuits in the IF before

In

particular

his
manual is
procedures
manufacturer's
apparently deficient receiver does not
response,
ponent
troubleshooting

TLINER ALIGNMENT

l, Connect the output

antenna terminals

sweep

2. Tune the TV

method

circuits

check the combined effect of the

chroma circuits is necessarv to obtain the desired

chroma response.

recommend

Other

all cases the manufacturer's method

receiver

preferred

are also reliable

procedure.

the technician must then

failure has

generator

is to first

dir.ectly.

into the

procedures.

set to the same channel.

The

chroma aligrment.

pre-tuning

procedures

IF

and the

for

alignment. SAMS

If

occurred and

(Refer

of the sweep

of the

to sweep one of the TV channels.

video-sweep

IF

then

is

pix

frequency

aligrment,

(usually

outline

sweep

manufacturer's

in most

and

complete

must

Fig.

to

television

align

aligred and

(45.75

chroma

Usually

practically

IF

traps by injecting

at a specified tuner

prealigrment

a

aligrment

is
PHOTOFACT

cases repeat the

realigrment

restore the required

consider that a

employ standard

28)
generator

set.

video

MHz) is

response

a touch-up

of all

procedures.

the best for

service

of an

com-

to the

Adjust

the

all

the

3. Connect the
directly to the tuner
Connect the Channel
DIRECT)

is normally the

where a demodulated
Set

4.

5. The

6. Select the marker

7.

the
sensitivity
to avoid
would distort the response
erroneous
screen.

oscillorope sweep and

exact

synchronization

proper

presentation

accomplished

setting the oscflloscope

(SWEEP

the horizontal
to the Channel B input

measure
T'lte

tuner response

oscilloscope.
the

response

adjustments for realignment.

ground

shield to minimize hum

the

to

tuner test

gid

of the mixer

sigral

CH A VOLTS/CM

and

operate the

overloading

picture

TIME/CM

the upper and

of alignment on

of the

for sinusoidal

to CH B

voltage

sweep

generator

See the manufacturer's

curve is now displayed

curve specifications and

clip of the oscilloscope

(Vertical)

A

point.

The tuner

tube

present.

is

control

generator

sweep

television receiver, which

the

curye and

the

generator

sweep
phase

and

respons€ curve. This

for external

terminal on the

lower response of

with

each

or sawtooth

position)
from the

horizontal input

and connecting

sweep

oscilloscope.

frequencies

instructions

pickup.

probe (set

test

or equivalent,

for

maximum

at low level
provide

oscilloscope

must be in

other for

is easily

sweep by

generator

required

the tuner.

on

necessary

the

probe

to

point

an

to

the

for

EP|MAF

SWE

GENERATOR

KER

AGC

BI

AS

.01V/cm

VIDEO

DETECTOR

@

0

@

0

o

ADJUST

HORIZONTAL

SIZ E

DIRECT

O­[:t>

o

@
@

28

Fig.29. Typical IF aligtment

set-up.

IF

ALIGNMENT

l.

Connect the
signal injection
generator

tuner

has

applied

2. Synchronize
generator
ALIGNMENT

3. Connect
probe

4.

Connect
video

5.

Set

viewing

at the

the

to

the television

the vertical probe

detector

the

CH

of

(Refer

output

to sweep the IF
been

antenna terminals.)

the oscilloscope

previously

as

procedure.

gound

output.

A VOLTS/CM

the response

Fig.

to

of the sweep generator

point

of the mixer.

properly

clip of the

set

chassis.

curye.

29)

frequency

aligrred,

sweep

described

oscilloscope

of the

gain

control for

Adjust

RF

oscilloscope

the

band.

sweep

with

the

in

the TIJNER

to the

sweep

(If

the

may

be

sweep

vertical

to

the

suitable

9€/"

3

o8

*lO"h-

-l

MHz

4

o8Mf'z

j-

8s%

I

+l5oh,-?c/o

6. Keep

7. Select

8. Follow

the
overloading. Follow
tions

check the

A sweep

the markers
Model

the response

sweep

on disabling

the marker

critical frequencies

and marker

simultaneously,

415,

is a big advantage.

the manufacturer's

generator

AGC.

curve and making

output level low

the manufacturer's recommenda-

generator

generator

such

instructions

f-

I

prevent

to

frequencies

of interest

capable of displaying

as the B & K-hecision

the alignment.

45.OO

MHz

required

(see

Fig.

for evaluating

to

30.)
all

Fig.

31 . Typical

ranges

to

sweep

frequencies.

used for

2. Apply
the
manufacturer's

3. Synchron4e
described

Use

4.
(Channel

curve

5.

Set
CH A

the

6. A re-sponse
should
of
bandpass

IF alignment.

the

celor

amplifiers

for

a demodulator

A) to

at the input

the

vertical

(VOLTS/CM)

screen.

be

seen. Select

interest.

specifications

VALLEY

r57"

Lr

chroma respons€

of response

approximately

Use

proper

instructions

the

tuner

curve

Refer

levels.

the

same IF

DC

bias to

(bandpass

oscilloscope

alignment.

probe

the

oscilloscope.

to

the demodtrlators.

gain

controls

for

similar to

the

to

the manufacturer's

and

MAX

roTo

MAx

4.50

MHZ

curve, showing

the 4l to

injection

the

color killer

amplifiers).

for the

sweep

for

Measure

a

marker

of

convenient

that

generator

atgnment

I

I

l

--l

tolerance

44MHz

level

that was

to enable

Refer

correct

the vertical

shown

bias

previously

as

the

response

the

oscilloscope

viewing

in Fig.

frequencies

instructions

procedure.

band

to

level.

input

size on

of

the

3l

for

Fig.30.

CHROMA

before
injection
injection
drastically.
f9.r

alignment.

Typical
ranges

starling

such

1. Ipave
connected

IF response

of response

ALIGNMENT

IF

alignment

this

of

video

specineA

Follow

direct

the

chroma

sweep

herein,

the

injection

sweep/marker

as for

curve,

levels.

(Refer

to Fig.

must

be

aligrment procedure.

is used

manufacturei's

IF

alignment.

rathei

the

response

of

video

generator

showing

32)

satisfactorily

than

the

curve

procedure

sweep

Set the

and

sweep

tolerance

completed

If

direct

IF

sweep

is

altered

explicitly

for

it ro-i

AGC

generator

NOTES

bias

29

SWEEP/MARKER

GENERATOR

il9

t-l-

Acl

ADJUS'

VERTIC

A
\y

o
a

Irlo
l=- ol

0

t==G-

fl@?

ADJUST

HORIZONTAL

SIZE

30

TELEVISION

Frg.32.

Typical

VIDEO

DETECTO

SET

chroma

FI RST

COLOR

alignment

AMP

DEMOOULATOR

sEcoNo

COLOR

(BANOPASS

set-up.

PRO€}E

AMP

AMP)

FM RECEIVER

Refer

Procedure:

l. Conriect a sweep

FM

receiver.

centered sweep.

2. Connect the
generator
scope and set the oscilloscope controls for external
horizontal sweep

Connect

3.
input of the

4. Adjust the oscilloscope vertical
controls

5. Set the marker
marker "pip"

6. AliCr the IF
specifications.

Move

7.
curve should be displayed,
should

to the Channel B input

the

for

probe

the

appear

generator

Sbt

the sweep

sweep

(SWEEP

vertical

FM

receiver.

display similar to that

generator

should be in the

amplifiers according to the manufactuter's

to the demodulator

exactly

ALIGNMENT

Fig.

to

33

to the

generator

voltage output

TIME/CM to CH B).

probe

hput

precisely

in the

to the demodulator

and horizontal

center

and the 10.7

center

mixer

input of the

for a lO.7

the

of

jack

of the oscillo-

shown in

to 10.7 MHz. The

of the

output.

MHz

(See

Fig.

Mllz

sweep

gain

Fig.33A.

bandpass.

The

"S"

"pip"

33B).

Adjust
faciurer's instructions
distances

increased and

10.7

Phase
scope. Typical
produce

distortion

shift
Dstortion due to non-linear

in the oscilloscope

A

tested. The
input of the oscilloscope,
circuit is
The

amount

can be

To make

procedure (Refer

Using

1.
sigral,
frequency

the demodulator

from center

MHz

measurements

a specific

sine wave

same sine wave

applied to the horizontal

of

calculated from the

an

apply a

decreased

frequency.

center

PHASE

applications

in

input is applied

phase

phase

to Fig.

audio sigral

to the audio

MEASUREMENT

may

phase

audio amplifiers or

waveform.

strift, and measurement

difference

resulting waveform.

measurements,

3a).

sine wave test

according

so the

as the

equal amounts

'made

be

are in

amplification

to the audio

input

and the

generator

network

applied

is

input of the oscilloscope.

between

sigral at the

being tested.

to the

marker

marker

with

circuits designed

other audio

is also

use

with

to the vertical

of the

the two

the

pure

a

output

manu-

moves

frequency

circuit being

equal

from the

an

oscillo-

to

phase

of

networks.

displayed

tested

signals

following

sinusoidal

desired test

is

\

I

@

VERTICAL

srzE

[

HORIZONTAL

stzE

MARKER

INPUT

SWEEP

GENERATOR

RF

OUT

SWEEP

VOLTAGE

.ca,$

DEMOOULATOR

Fig.33.

Typical

FM

receiver

aligrment

set-up.

3l

GENERATOR

o

AUDIO

SIGNAL

@

"@r

o

O

P^fl@fr

"lJ.

['.l9

lo- @l

l­I

la

-

rt,

1J

CH8

NO AMPLITUDE

.

T{O

PHASE

OISTORTION

SHIFT

Fig.

34.

AMPLITUDE

NO PHASE

Typical

OISTORTION

phase

SHIFT

AUDIO

BEING TESTED

measurement

VERTICAL

SIZE

LOAD

alignment

HORIZONTAL

SIZE

set-up.

NOTES

ISoO

oUT oF

AMPLITUOE

PHASE

Fig. 35. Typical

32

PHASE

OISTORTION
SHIFT

phase

AMPLITUDE

90" OUT

measurement

PHASE

oscilloscope

OISTORTION

SHIFT

PHASE

OF

displays.

2. Set

the signal

ating

level of the

circuit's output may

the

test circuit is overdriven,

the oscilloscope

reduced.

3.

Connect the
circuit.

4.

Set the

5.

Connect
the test
to
be reversed.)

Adjust

6.
viewing

7. Some
sjsrals
diagonal
properly

A

pattern.

Phase
elliptical
can be
Fig.36.

SWEEP TIME/CM

the

circuit.

the vertical

the

size.

typical

are

line.

adjusted,

phase

90'

shift

oscilloscope pattern.

calculated

generator

circuit

is clipped

Channel B

Channel

(The

and horizontal

Channel

in

of les

A and B

results

plrase,

If the

this line

shift

from

the oscilloscope

output for

being

be

observed on the

the

and the

probe

to the

control to

A INPUT

input

and output

oscilloscope

gain

are shown

the

oscilloscope

vertical

produces

(or

and horizontal

is

at a 45o

more)

The

the normal

tested.

sine wave

signal level

output

CH B.

probe

controls

Fig.

in

trace

angle.

a

circular

than

90o

amount

trace

If

oscilloscope.

to

test

for

35. If

produces

of

oper-

desired,

display on

must

of the test

the

input of

connections

inputs

a

suitable

the

is a

straight

eain

oscilloscope

phase

shift

ai

shown in

the

be

may

two

-are

an

If

UNKNOWN FREqUENCY

TO VERTICAL

STANOARD

TO

HOR IZONTAL

INPUT,

FREQUENCY

iNPUT

SEE NOTE((t

RAT

STANDARO

IO

UN KN

TO

2.1

OF

OI./

N

))

sEENorE

l:l

/2OSt

llz. I

NOTE:

Fig.

ANYONE
UPON PHASE

37.

Lissajous

ment.

OF

THESE FIGURES OEPENOING

RELATIONSHIP

waveforms

used for

frequency

measure-

FREQUENCY

Procedure:

l. Connect

C-H

B__INPUT jack
SWEEP­external

2.

Connect
unknown

3.

Adjust
convenient,

4.

thr
the

resulting

ratio

Fig.

36. Phase

the

sine wave

.TIMEICM
horizontal

the vertical

frequency.

the

Channel

easy-to-read

pattern,

between

the

H

-A

6
g

=

PHASE

shift calculation.

MEASUREMENT

of known
of the
control

input.

input

oscilloscope

to CH

probe

A

and B gain

display.

called

two

a

frequencies.

(CH

Ussajous pattern,

ANGLE

frequency

and

n.

ftris provides

A INpUT)

controls

S; Fig.

to the

set

to

for

shows

j7.

the

the

a

SQUARE

WAVE

INTRODUCTION

A

square wave generator
scope,
various
square.wave
of

ya_v9_ls
tubes

and

signal.
stray

response

reproduction

a_mplltler
limitations.-.Poorly
introduce
is

number

t-ry9

500
Irequency

ry_spond

2l

it' we
4gtng

oltterent
controlled
output
harmonics
sees
lnstruments

such

types

odd

harmonics

1.5

ryj9ct9d

kHz,

2.5 kHz,3.5

and

transistors

reproduce

Interelectrode

capacitances

are a few

can

unsatisfactory.

st harmonic.

distortion

As

st^ated-

of

odd

amplifier,

-3n

Hz

only,

we

to

The

need

realize

normal

_lrequencies.

signal

qual^ity

.

of

when

or

as this

of distortion

of a

into

a square

of

.a.

minimize

before,
harmonics.

but

can

input

for

square

that

use

with

of

the,square

amplifying

voices.

TESTING

instrument,

given

of

as

we

by
signals

some

to pass

present

frequency

that frequency.

a

circuir,

kHz,

also

are

non-linear,

wave

capacitances,

well

as
of
square-

designed

to

determine

a

limited

the

factors

wave

the

point

the

a

square
By

can

.evaluite

injecting

from

wave

audio

simultaneously

With

which

we

signal

*ave)_which

complex

OF AMPLIFIERS

and

a low-distortion

can be

in electronic

contains

If a

frequency

provided.

are

it is

which

distortion

or defective

injecting

a square

how
500H2

evaluation

amplifiers

a

square
can

of many

.

difficult

is

identical

junction

device

which

sigral.

caused by

where

their

wave

contains

a 500

airplifier

wave

the

up

becomes

a large

wave,

evaluate

frequenciis

ii what'the

waveforms

used

a large

500i2

componenis

and
prevent

A

amplifiirrs

amplifier

to the

will

oscillo_
to display
circuiti.

number

Sirice

vacuum

to amplify

to

the iirpui

capacitanies,

tiansformei

faithful

well-desigrred

performanci

a large

Hz

sine waie

response

of ihe

would

l5th

apparent

be

rbquired

number

we

have

ihe

input

amplifier

of

musical

A

square

of

these

can

at

sami

or

of

a

and

(the

33

The
extremely flat so that
distortion that
response.
DC as it
frequencies.
quency
low erd
of the bandpass;
of the square
end of

of

the amplifier bandpass

It

should
amplifier
espicially
ariplifieis).

-amplifier

of
overall-amplifier

deficiencies

some
wave sigral.

[he amplifier,

testing

specifications

judgment

better

TESTING

Connect

l.

the input

2. Connect
output

wave output of

square

may be observed

The oscilloscope

will

introduce

When

the

square

the amplifier

of

wave, distortion

be noted

should

important

fhe square

performance and

Whether a si-1,;

on

PROCEDURE

the

of

the CH

of the amplifier

the

checking

wave input should

however,

be made

in limited

quality.

not readily

it is

the

amplifier

perforrnance.

its

of

output

the

amplifier

B test

the

it does not

least distortion,

bandpass up

':ecause

that the

wave signal

The square

important

(Refer

of

signal

when evaluating amplifier

vertical input

ampliher response,

toward

of the harmonic content

will

occur

reached.

is

actual response

;.rsing

a sine

bandwidth

provides

will

apparent

or

wave

probe
being

square

that

known in order

be

Fig. 38)

to

the square

tested.

being

the oscilloscope

of

tested'

generator

contribute

sttould be set

especially

be

before

wave sigrral.

amplifiers

give

wave also

when using

the manufacturer's

wave

must

to any

at

the fre-

varied from

the upper

the upper

of

check

This is

(voice

quick

a

an,

wave is used

check-

estimate of

will

reveal

a sine

to make a

generator to

to the

be

to

low

the

end

for

an

DC

If

3.

the
sufficiently
component
AC-GNDDC switch.
used
frequencies

4. Adjust the
viewing height.

Adjust

5.
wave display

For

6.
use the 5X magrrification.

ANALYZING THE

The

half-cycle is created by

high frequency sine wave components.

and
true for the rapid
maximum amplitude
half-cycle
amplitude alone
produce
of one

square

Distortion

categories:

component

low to allow both the

to be

without affecting the results

(below

vertical

sweep time

the

on the

a ciose-up

short

point.

rounding of the square corners at

a

view

WAVEFOR-II{S

time which

rise

drop

Therefore, a theoretical

of the high frequency components should

wave

cycle

can

of the

viewed,

5 tlz).

to zero

be

use the DC

However,

gain

control

control

screen.

portion

of a

occurs

the

in-phase sum

the end of the half-cycle from

at

amplitude

(See

Fig. 39).

classified

circuit being

AC

the

except

for

for one

of

the

at the beginning of the

of all the medium

into three distinct

tested

AC

and

position

position

cycle

The

at the 180- or

all four

of the

may be

at very low

a convenient

of

square

wave,

square

same holds

reduction in

points

DC

I

l

is

I

t

SOUARE WAVE

GENEFATOR

@

o

p

o

pofr@i9i

CHB

ADJUST VERT

GAIN FOR

CONVENI ENT

VIEWING

HEIGHT

FI

AMPLI

BEING

CIRCUIT

TESTED

ER

OUTPUT

,ADJUST

SPEED

CYCLE DISPLAY

SWEEP

FOR 1

34

Fig.

Equipment set-up

38.

for square

wave testing of amplifiers.

Fig.39.

Fig.40.

Square wave response with high frequency

loss.

poor low

Response
and nlsn

enos.

curve

of amplifier

with

frequency

The first

t.

change
.otnil.^
an amplifier
Iilters created
will create
response curve.

The second

2.

change

waveshape

vacuum

as

extreme case,

clipper

3. The third
distortion
more components

In actual

wave component

frequency-selective

a
inductance
difference
phase

distortion

wave testing

distorted

the
amplitude

In a typical

accurately

circuit.
revealing
compensated
applied

This figure indicates satisfactory

4lA.
response
low frequency
applied

Fig.

41B.
the region
overcompensation

rise

the

at

As

wave

can

up

to the l5th or

ly 40

times the
rule of thumb, it is
require at least
the

complete spectrum.

Hz

100

about 4000

10,000

is

norhal

from

waveform.

circuit

peaks

is

in waveshape

to non-linear

tubes,

network.

is delay

produced

practice

(sinusoidal

or both.

phase

in

or delay distortion.

practical

of

square

phase

and

wide band

reveals

The response

poor

low-frequency

high-frequency

to

input of this

the

(approximately I kFIz

response.

to the input

This figure displays

of 1000

top of the leading

of thumb, it can

a rule

be used

square

[Iz, a 1000 Hz

to reveal response and

20th odd harmonic

fundamental

a two-frequency check

wave will

FIz. To

amplitude

In other

of

by

combination

or dips

non-linear

an iron core

a deliberate

by a shift

of a complex
a reduction

network

presence

The

angle

circuitry,

wave includes a combination

distortion clues.

many distortion characteristics

of an amplifier

of this same amplifier

to 4000llz but clearly

at the higher

seen

ln the case

analyze

square

refers to

distortion

words,

resonant

in an

distortion

produced

components

non-linear circuit such

phase distortion,

or

harmonic) is usually

between comPonents,

amplifier, a square

response . along

boost. A l0O

amplifier

fo

Next, a l0O0

good

l0 kHz region

edge of the square

be

of the

that rvide-band circuitry

encompass components

above

wave should be satisfactory.

and

a component

of

the introduciion

networks

of reactive

otherwise

by

transformer,

phase

in

waveform.

in amplitude of a square

which includes capacity,

ofthe C

Therefore, in square

we will usually

is indicated in

will

medium frequency

2 Wlz) but

frequency response

safely

or up to approximate-

square

to

illustrated by

4000 Hz and beyond

or selective

comPonents

flat frequency

and refers

application

elements such

or

between one

or L introduces a

wave check

with over'

Hz

squ,ue

appear

shows

Hz

squiue

appear as in

will

reveals the

by the sharp

wave.

said that a square

phase

relationships

wave. Using this

properly

the

of

to a

of the

in an

and

as

which is

caused by

creating

{ind that

the

of

Fig. 40'

wave

Fig.

as in

poor

wave

will

analyze

Fig. 40,

up to

a

in

a

or

of

in

a

Hz

roo

SOUARE

IAVE

Fie.41 .

-

Resultant
from amplifier

100

Hz and I kHz

in Fig.45.

square waves

Now,
shows a rise from
flattening
we

100 Hz

and

same

low-frequency

such as to only depress
the square wave,
obtained. However,
ponent,
element,
producing

the region between

from

out

expect that the higher frequency

can

square wave will be relatively normal in amplitude

phase

but that the lower frequency

square

If the

wave, will

combination of

as

already noted, is usually

causing, in turn,

the strong tilt of Fig.

poor

beyond

response

a curve

reduction

100 Hz

and 4000

low-frequency

1000

and 4000

components in

components in this

be strongly

of this amplifier. See

elements

the low

similar

phase

a

modified

in this amplifier were

frequency

Fig.

to

in amplitude to

caused

strift

of the component,

4lA. Fig.

Hz

Fig.40

in

response to a

Hz. Therefore,

by the

Fig.

components in

42

by a reactive

43 reveals

the

poor

41A.

would be

a

com-

35

a

Fxl

OUT-OF.PHASE

Fig.42.

Reduction of square
frequency

Fig.

43. Square wave
phase

component in a tuned

tilt resulting from

shift.

wave

fundamental

circuit.

3rd harmonic

Fig.

Tilt resulting

45.
trequency

gaphical
tilt is

phase-shifted
very
the square

by
direction.
frequency
opposite
polarity

seen to be

slight

Fig.

44

phase

a l0'

development

3rd harmonic.

shifts in

wave.

indicates the

shift of a
Fig.
component in

in

the two

of the

checked through

Fig.

45
been reduced
noted
characterized
the

square wave.

indicates low-frequency

in

that these

by

from phase

in a lagging

of a

caused

phase

tilt

low-frequency element

45

indicates a 10'

a lagging direction.

cases

phase

angle in

algebraic

addition

amplitude

examples

change in

shift of

fundamental

direction.

similarly
by the strong

are

in square wave

tilted

square

influence

It

also

becomes evident

quickly

shown

shape

phase

strift in

because of the

the two

of

cases as

components.

difference

components

and

shifted

of low-frequency

phase.

in

distortion

shape of the flat top

wave.

of the

that

up by

tilt in

produced

in a leading

a lowl

The

tilts

can be

which

have

It will

portion

The

are

in

be

are

of

36

FXI

Fig.

OUT

OF

,14.

Tilt resulting
frequency

PHASE

(LEAD)

phase

fro.m

in a leading

shift

of

direction.

fundamental

Fig.

low-frequency

46.
shift.

Fig.

4lB,

previously
overshoot produced
higher
overshoot
edge
explained
square wave,

the

components.

occurs
in the
greater
sum along the

frequencies.

makes

of the

itself

square wave.

by remembering

the sharp

summation

of a

If

an abnormal

at high frequencies,

square wave will

than

other components

leading edge.

component

discussed,

by rising

It

should
evident

This

that

rise ofthe

practically

the

be

loss

revealed

amplifier

again be

at

the top of

characteristic

in a normal
leading edge

inlinite

number

rise

in amplifier

high-frequency

phase

and

high-frequency

response

noted that

at th-e

this

the leading

relationship

well-shaped

is

created by

of harmonic

response

components

ii

amplified disproportionately

creating a higher

algebraic

Fig.

47.

Effect

of high-frequency

boost and

poor

damping.

Fig.

accompanied

sinusoidal
the square
high "Q"

sudden transition

indicates high-frequency boost in an amplifier

47

by a lightly damped

"shock"

transient. The
type of diminishing oscillation along the top of
wave

indicates

network in the amplifier circuit. In this

a transient oscillation in a relatively

in the square wave

potential

from

case,
a sharply

the

rising, relatively high-frequency voltage, to a level value of
low-frequency

voltage,

supplies

the energy for

oscillation in

Fig.

48.

Effect

of high-frequency boost

damping.

the resonant network.
reasonably heavily
oscillation may

Fig.

be

49

summarizes the

If this network

damped, then

produced

serves as a handy reference.

good

urd

the

in

a single

amp'lifier is

cycle transient

as indicated in Fig. 48.

preceding

explanations

and

A. Frequency distortion.

reduction ol
ponent).

Low lrequency

G. High lrequency loss

shiIt.

low lrequency com­phcse

No

phose

Fig.

(cmplitude

shilt.

shill. E.

phose

ond

B. Ipw

H. Domped

49. Summary of waveform

frequency boost

oted lundamentol).

Iow lrequency loss

shilt.

qscillollon

analysis for

(occentu-

phose

ond

square wave

testing

C. Hiqh lrequency

shiIt.

High

lrequency loss

quency

phose

Low lrequency phose
thickend

by hum-voltoge).

of amplifiers.

loss-No

shilt.

ond low

shilt

pbare

trc-

(trcco

37

CIRCUIT

DESCRIPTION

The
breakdown of the
by reference to the schematic diagram.

GENERAL

vertical
network. The outputs of
switched,
switching of the CH
mined
LOGIC. The main vertical amplifier
OUTPUT AMPLIFIER, which drives
plares

amplifier.
calibrated
CH

converter
to

VERTICAL

identical circuitry
both. CH

transistor
fier
side

Ql04
gain

provide gains

'control

vertically across the

MODE LOGIC

from

MODE LOGIC

controlled
the
LOW, turning
amplifier.
goes
amplifier.
ICl03 are
CHOPPED

ALTERNATE

amplifier

sweep circuits.

the

amplifier.

VERTICAL

the

block diagam,

oscilloscope.

Basically, the oscilloscope consists

preamplifiers,

desired, into

as

position

the

by

of the cRT.

Horizontal deflection is

Drive

to the horizontal

sweep speed

preamplifier

B

All

supply

provides

the CRT.

Channel

A will

vertical

The

Ql0l

with output

panel

drive the differential amplifier

is changed

VRl02

Transistor

Trigger

IClOl

mode

The

panel

front

low turning on

When DUAL is selected

is turned

When the SWEFP

CH B

trigger amplifier sigral is

The

selected

vertical output

when X-Y operation is selected.

voltages are

a

PREAMPLIFIERS

A and Channel

and circuit

described below.

be

preamplifier

which forms a balanced

sigrrals

DC BAL

in

of 5,2, and l.

provides

array

circuitry.

amplifier

delivers the signal

and

of operation

by ICl03 and

MODE switch,

on the

When CH B is selected

switched on

mode, and after

mode:

AMPLIFIER

sigral

Fig.

50, outlines

Circuit details are obtained

each having its own input Attenuator

the vertical

the main vertical

A and CH B

of the

circuits

fully regulated and a

regulated,

opposite

of

control. Emitter followers

the emitters of

a DC component

screen.

ICl0l is

Ql07

ICl04.

CH A

the CH

and off at

When

providing a trigger

on,

TIME/CM switch

from

stage consisting

preamplifiers

MODE

provided

amplifier

or by

2kV,

B

operation is

consists

polarity. VRl0l

front

The

turned on

and

Ql08

to the

(CH

A, CH B, and DUAL) is

When

the

Q

preamplifier

the

preamplifier_and

B

the

a 200 kHz rate for the

each sweep

DUAL,

in

applied

preamplifiers

the

the

circuit

of two identical

preamplifiers

amplifier.

switch

feeds the

vertical deflection

the

by the

is furnished by

the signal from the

accelerated

preamplifiers

of dual

differential ampli-

and

Ql05

Ql05

panel POSITION

to move the trace

or off by the

buffers the signal

trigger

CH A is selected

output of ICl03

output

Q

and Q outputs of

Q

the

is in CH

to the

of transistors

can be

is

MODE

and

VERTICAL

horizontal

DC-to-DC

potential

contain

the

same

FET

Q103

QI06.

and

Ql06

amplifier.

and

of

when in

A trigger

CH

sigtal

position,

B

horizontal

is

applied

Ql13

The

deter-

for

input
is the

and

Stage

to

by

goes

trigger

ICl03

trigger

to the

to
to

which amplifies

Q120,
drive the
DC

frequency

TRIGGER

MODE switch
enables trigger amplifier
trigger amplifier
output
on in all
CH B.

SYNC

preamplifiers)
is
inverted
selected
adds

SYNC SEPARATOR

routed to

and
developed
input
The output of
posite

switch
the horizontal sync
to

lpSEC,

horizontal

SWEEP CIRCUIT

and
gates
SWEEP CONTROL flip-flop
the clock waveform,
turning off

and resistors selected
form
ramp
is

of IC30l is held
pulses

ramp exceeds the level set by
IC 302
set input forces the
Q307,

vertical deflection

balance control,

compensation

CIRCUIT

The

is fed thru transistor

AMPLIFIER AND INVERTER

Source

then fed

DC

a

When VIDEO*

19.

Q3

signal.

video signal.

When

(.lms

pass

to the

The trigger signal

to

the

of

Transistors

MILLER

a

voltage. The

fed to the holdoff

As

until the sweep

places

terminating

source,

trigger

5105.

positions

switch

or

to differential amplifier

(SLOPE-)

by SYNC switch

COMPONENT

the

SYNC

Q320

across C332

Positive-going

Q320

FRAME

in the

.5

to

sweep circuit. In the

19 is turned off, removing C33l and allowing

Q3

pulses

sync

SCHMITT

IC303. The output

Q307

soon as

a low on the set

the signal

while

adjustments.

either
Selecting

Ql07

and

Ql27

SWEEP

of the

5303

EXTERNAL triggering.

sec),

to initiate

Q308

INTEGRATING circuit

the Q output of IC30l

selects

non-inverted

or

to the output of

-

is selected, the

or

SEPARATOR

is held at cutoff

corresponding

pulses

corresponds

positions

19 is on; this allows C33l to hlter out

Q3

pulses, permitting

pass

to

passes

TRIGGER

the Q output

and

by the

ramp

sweep

circuit

low by IC303 to exclude any

ramp is terminated.

output

Q

the

sweep.

to the levels
plates
VRIOI and

Q128.

switch

5304.

to the sweep circuit.

pulses

IC30l. On

the

Q309

IC302

the CRT.

of

TCll3 are high-

CH A or
and

thru emitter

VR309

input of IC30l.

of

CH B, is selected by

CH A or

either

and CH

Q108,

TIME/CM switch

either INTERNAL

LEVEL

circuit consisting

drive

to the

of the

LINE positions,

circuit

sweep.

and the

SWEEP

from the collector

and IC303.

IC30l high

trigger

The

Q3l3

Q313.

The trigger signal

IC305.

(SLOPE+)

control

IC305.

output

negative

by a

to an average

Q320

sync tips

SWEEP

vertical

only

consisting of

from IC303 clock the

the

negative

of IC30l

timing capacitors

TIME/CM

to

goes

When the sweep

(SWEEP

required to
VRl05

out

of the com-

follower

provide

low, the reset

A low on the

which turns on

is a

DUAL

B enables

amplifier

turned

is

except

(from

Either

of 1C305

value

TIME/CM
sync

the

signal

VR3l0

of

Q320

voltage

ofthe

of cutoff.

pulses

50irSEC to

Q303,

two

edge of

goes

low,

switch,

a linear

of

Q309

new clock

LENGTH),

is

is

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39

AUTO

SWEEP

Transistors
SWEEP
(AUTO)

C303
reset

determined
SWEEP TIME/CM

transistors

off

sipal.

circuit.

charges

of IC30l

and enabling the

Q304,

When

and no

and turns

and allows a

by the resistor

Q3O4

Q305,

the trigger level

sigral is

switch.

and

Q305

sweep to trigger on the

and

present

Q306

When

at
this

on,

sweep

and capacitor selected by

a trigger signal

discharge

form the AUTO

Q306

control is

the

trigger

places

C303,

a low on the

turning

to recirculate

pulled

out

amplifier,

a rate

at

present,

is

Q306

incoming

the

CHOPPING

Two NAND
20Okllz
positions
selected. IC3O4
during

VOLT

I

Transistors

wave.

OSCILLATOR

CHOPPING

of the

retrace

and

CAL SIGNAL

VR30l adjusts

gates

from

OSCILLATOR

swEEP TIME/CM

provides

when

and

Q30l

the amplitude of the CAL SIGNAL.

1C304

pulse

a

chopping.

Q302

and IC305

activared

switch when

for

blanking

provide

a

in the

Hz

60

form

CHOp

DUAL

the trace

is

square

a

HORIZONTAL

The
thru VR306
amplifier

VR305
horizontal

thru
and

Q3l7

plates
adjustment and VR304
adjustment.

is

When

IC303 and the

the horizontal

and

of

High voltage
tical amplifier
operating.

Line voltage
amplifier

POWER on-off
to

an ac
caution when
ting

exposed high

AMPLIFIER

sweep ramp

(timing

consisting of

a horizontal

position

in the

Q318

the

Up to

power

&
power

from

adj.) to the input of the

centering

control.

X-Y

mode,
CHB
amplifier. The

is applied to the horizontal

cRT. vR303

up to 2000 volts is

power

&

180

(120

volts dc is

or 240 VAC) is

supply

switch any time the oscilloscope

source, even if

the housing is removed

voltage

the

collector of

Q314,

Q315, Q317,

adjustment and VR3

transistor

signal is

is the magnification

applied

output of

is the

Q3l3

X5

is applied

Q309

horizontal

and

Q318.

is the

is

turned

to both

magnification

Q3l2
transistors
deflection

centering

off

MAINTENANCE

present

supply board when the oscilloscope is

board,

could result

on the CRT and ver-

present

on the sweep board.

present

power

turned off. Always observe

on the vertical

transformer,

is connected

from the unit.

in fatal electric

the

and

Contac-

shock.

POWER

operating

provided
output

DC-to-DC
output
voltage
fed
provide
operating

AND

cedure

CRT ROTATION ADJUSTMENT

SI.JPPLY

power

The

the oscilloscope.

Regulated

stages require

The

of T10l

dividers

to a

CALIBRATION

Internal

can be located

1. Loosen two

output

for

all logic

accelerating

converter

regulator

a

constant accelerating

conditions.

B & K.PRECISION

DYNASCAN CORPORATION

adjustments outlined

supply

the 180V.
voltage

is rectified

to the

circuit

SERVICE

2815 W. Irving

Chicago, Illinois

screws on rear

provides

voltages

consisting

CRT. A

by

of

amplifier

and

for the

of

and filtered

portion

consisting

DEPARTMENT

TEST EQUIPMENT

Park Road

reference

panel

all voltages

+10,

CRT is derived

Ql42

of

potential

60618

in the

to Fig.5l

with

necessary

and -8, and

circuits.

and T101.

and applied

of the high voltage

Q129

under

calibration

and 52.

adjustment

Amplifier

and

+5

from a

Ql30

var.ied

slots.

for

are

The

thru

is

to

pro-

HOUSING REMOVAL

l. Remove 6 screws; 2 on left side, 2 on

on top.

2.

Lift cover off

24O VAC

l. Remove housing from

2. Remove

3.

Rotate

4.

Replace 0.7A fine

5.

Replace housing.

The calibration

which

can be
equipment. Additional
compensation and horizontal
attempted
specified
information

40

test equipment.

scope.

OPERATION

scope.

plug

from Pl0l.

plug

I 80"

performed

without

for this oscilloscope

reinsert

and

with 0.3A

adjustments outlined

with

a minimum of

intemal adjustments

complete service

sweep linearity

Requests

on

fuse.

should be

right

side, and

Pl0l

.

are

here

specialized test

of frequency

should not be

information and

for

complete

addressed

2

those

service

to:

2. Grasp

3.

DC

BALANCE

l. Adjust

2. Adjust

3. Rotate

4.

VERTICAL

a square wave
accuracy is

cover and rotate

horizontal

Tighten two

cH

vertically

5VICM while
If the trace

performing

(side

movement
performing

The following

graticule

controls to obtain

B).

i

on

VOLTS/CM

the

panel

GAIN ADJUSTMENT

available.

to aligr horizontal

line.

screws.

ADJUSTMENT

a horizontal trace.

pOStfION

the CRT.

observing the trace.

moves vertically more than

STEP 3,

screwdriver adjustment)

of the trace

STEP 3.

adjustments

generator

control to

switch from lV/CM

adjust the CH A or CH B DC

does not exceed 5mm whiie

should be attempted

with l%

or belter

trace with

(CH

or

A

center

so that the vertical

the

trace

to 2V/CM to

while

5mm

BAL

only if

amplitude

VR1 06

@

FUSE:

-O.7A

120V

240V -O.3A

120V

F

TC113

@

il

'IO

VR

VRl04

@

1

VR105

@

TC',r03 TC101

@@@

TC109

@@@

I

VR4O1

TC107

VR103

?tt ,'h

TC102

rC108

VR108

@

VR109

VR107

@ HHE

@

,U,

Q^'^'"o

VR113

TC106

TC104TC105

@@@

TC112

TC1

@@@

10

/-r

\-i

TC1

1 1

P1

01

il

VR111

F

ROTATE
CHANGE

vR1O1

VB103
VR'I04
VR105
VR 106
VR 1O7
VR108
vR109
VR110
VR1'I1
VR113
VR4O1

VR4O2

240V

TO

PLUG

VOLTAGE

CHA

DC

BAL

CHA

GAIN ADJ

HIGH

FREQ

CENT

ADJ

ASTIG

_

1.9

KV ADJ

INTENSITY

18OV

+

X

GAIN
CHB
CHB
CHA DC
CHB DC

ADJ

ADJ

ADJ

DC

BAL

GAIN ADJ

BAL
BAL

(1)

ADJ

(2)
(2}

hocediue

1. Set

CH A

2.

Apply I kHz
CH A input

3.

4. Repeat

HORIZONTAL

l.

VRl03

Adjust

5cm

Set
rotation.

steps 2

deflection.

<>POSITION control

Fig.

5l'

calibration

CH B VOLTS/CM

and

square wave

connector. Set mode

for exactly

and 3 for CHB

POSITION ADJUSTMENT

switch

of 50mV

switch to

5 cm

of deflection

and

to

the mechanical

FRONT

PANEL

diagram,

to .OIV/CM.

peak-to-peak

adjust VRl13

CH

on CRT.

center

vertical

A.

into

for

of

amplifier

and

2. Set

3.

Adjust

horizontally

4.

Tum
amount
minimum

ASTIGMATISM

l. Rotate

2.

Adjust

small,

power

supply

SWEEP

TIME/CM

VR305

the <>POSITION

of

SWEEP

FOCUS

bright

so that

centered

deflection

of

4

cm.

ADJUSTMENT

TIME/CM

control

spot with

TOP

board.

switch to

on CRT.

control full

in both

INTENSITY

lmS/CM.

the

line on

directions

switch

and VRl06 (ASTIG.)

to EXT

CW

set

VIEW

at

the

scope

and CCW.

should

H. position.

midrange.

for

is

The

be a

a

4l

TC301

@

VR3O9

@

VR3O5

@

VR3O6

@

VR3O4

@

VR3O3

@

vR3'to

@

VR3O1
VR3O3
VR3O4 MAG
VR3O5
VR306
VR3O8
VR3O9
VR311
TC301

CAL

MAG

POS
TIME

X

CENT
WIDTH
TRIG
TIME

FOIL SIDE

ADJ

GAIN

CENT ADJ
ADJ

ADJ

ADJ

ADJ

ADJ

(lps-5Ops)

ADJ

VIEW

VR311

Fig.

52.

Calibration

diagram,

horizontal

amplifier

VR3O1

@

VR3O8

@

board.

42

WARRANTY

SERVICE

INSTRUCTIONS

MAINTENANCE

i.

2.

If
your

product,

a

parts
department,

enclosed

Illinois 60635

result of unauthorized
removed.

damages
damages,

state.

authorized
cannot

lrving

to the

Refer
adjustments

that may

If the above-mentioned

your

with

Enclose
or
agency

your

DYNASCAN

period of one

DYNASCAN

To obtain

a

ship PREPAID

(see

list of

distributor

local

and the

upon delivery to an

warranty registration

Exclusions:

DYNASCAN

resulting

so the above

warranty

This

your

I.or

to

obtained

be

Park Road, Chicago,

pack

unit,

letter describing

(UPS

enclosed

list

authorized B &

for the

CORPORATTON
component

year

from the

will, without charge, repair

accompanied by

warranty coverage,

within five

This warranty

convenienoe

make repairs or can refer

alterations

shall not be liable for any

from loss of

limitation

you

gives

locally,

section

be applicable.

procedures do

sicurely

it

(preferably in the original carton

problem and

the

preferred) to

with

unit).

K-Precision

name of

your

Service

K-Precision

B &

DYNASCAN

28 l5 West lrving

Chicago,

LIMITED

parts

date of

authorized B &

proof

(5

days)

does

specific rights and

wr) suggest

please

Illinois 60618,

ONE-YEAR

warrants to the original

will be

thereof,

purchase.

of the date

product

this

card to

use. Some states do

DYNASCAN, B &

from the

or exclusion may not apply

send

date of

not

apply

repairs.

or

you

you

the unit

properly packaged

your

of

not

B &

correct

include

the nearest B &

service agencies

nearest

service agency, or write

Deprtment

Product Group

CORPORATION

Park Road

Illinois

60618

WARRANTY

free from defects

or replace, at

K-PRECISION

purchase

of

must be

purchase.

in the event

It

void if

is

consequential

not

allow

you

may also

your

contact

to the nearest

to B &

B &

K-PRECISION

K-Precision

problem

the

instruction

you

are experiencing

or double-packed).

your

purchaser

its option,defective

service contractor

the form of a sales receipt.

in

registered by completing

K-PRECISION,

of

misuse

serial

the

damages, including

limitation

you.

to

have other rights

K-PRECISION distributor,

service contractor.

to avoid damage

and address.

name

K-Precision

has

in workmanship and materials

or abuse

number is altered'

Service Department,23l5

authorized

misplaced, contact

been

its

that

product
or the factory

P.O. Box 35080, Chicago,

of the

of incidental or

which

in shipment.

Deliver

for

to,

manual

service

to:

K-PRECISION

B &

or component

and mailing the

product

without

consequential

vary from state to

who

If warranty scrvice

service

or

defaced

limitation

may be

for

as a

or

West

43

OMIONAL

ACCESSORIES

following

The

able to

complement

B & K-PRECISION

your

Model

1476

MODEL LC-74 PROTECTIVE COVER

This rugged

venience and

pocket provides

handy

A

MODEL RM.I4 RACK MOI.JNTING

kit includes everything needed to

This
oscilloscope in a standard
hardware,

and complete instructions.

INSTRUMENT CONNECTING

following

The

purchased

be
oscilloscope

Model

grained

protection

leatherette cover

when transporting the oscilloscope.

stowage

for

KIT

19"

rack, including

CABLES

B & K-PRECISION cables, which

separately,

may be

useful for

directly to other equipment:

CC-41.

36'

RG/58U with a

each end.

Model

CC-42. 36' RG/58U

UHF connector

Model

CC-43.

banana

Model

plugs.

CC-44. 36" RG/58U connector

microphone

(PL-259).

36"

connector.

Model CC-45. 36'

type N

connector.

RG/58U with BNC connector

RG/58U

with

with

accessories

are avail-

Oscilloscope.

provides

probes.

mount the

panel,

connecting

BNC connector

BNC connector and

and coaxial

BNC connector and

con-

may

your

on

and

MODEL PR-37

The B &

designed

PR-37
tion. A
reference
The

52"

with

ed
sulating
tion capacitor
probing
nearby

The

BNC

fitting,

The

IC

DIP,

making it
The PR-37
different
for instant
nected.
vinyl

case.

K-PRECISION

for

use

is

a slim-body

three-position

position

coaxial

the PR-37

tip BNC

adjustment

dense

components.

BNC

adapter

ideal for interface

guides

tip

is available

colors are

identification

The PR-37

Model PR-37G

DELUXE

with wideband

that

cable is extremely

are

tip adapter, IC

solid-state

the

almost impossible

particularly

and

PROBE

probe

of

switch select

grounds

a spring-loaded

tool. The

circuitry with

tip converts

probe

with

contact

in

both

of the

channel

accessories

grey

is

Model

PR-37

oscilloscopes

precision

the tip

tip

grey

useful with

lightweight

l0:l

or direct

through

flexible.

and an insulated
insulating

the

test

to

come

Accessories

retractable

no danger

probe

points

into

any

short two

and red

a dual-trace

which

to

in

convenient zippered

PR-37R

and

probe

deluxe

to

I0O MHz.

construc-

modes,

a 9M

resistor.

includ-

tip

cover,

compensa-

tip is designed

of

shorting

tip

or output

pin

colors.

push-on

into a

pins

a

jacks.

of i standard

of

an IC.

probes

scope

is

orobe

is red.

is

The

or a

in-

for

of

con-

MODEL

tion envelope of

This

PR.32 RF

probe

permits

DEMODULATOR PROBE

display and analysis

RF signals to 250MHz

25OMHz). Input impedance

pF

4.5

by
stray

maximum. Internal

pickup.

RF

of the modula-

is 30kO

minimum, shunted

shielding protects

C6dB

against

@

ffi

F

West

6460

Chicago,

trlYNASCAN

COF|POF|ATION

Cortland
Illinois

Street

60635

480-262-9-00t