Tektronix 7B10, 71310 Instruction Manual

'HBktfDnix

COMMITTED TO EXCELLENCE

PLEASE CHECK FOR

CHANGE INFORMATION

AT THE REAR

OF THIS MANUAL.

7B10

TIME

BASE

OPERATORS

INSTRUCTION

MANUAL

Tektronix, Inc.

P.O. Box

500

Beaverton,

Oregon 97077

Serial Number

070-2317-00

Prodlict Group 42

First Printing SEP 1978

Revised JUN 1985

Copyright

-

1978

Tektronix,

Inc. All

rights

reserved.

Contents of this

publication

may not

be reproduced

in any

form \without the \written

permission of Tektronix,

Inc.

Products of Tektronix,

Inc. and

its subsidiaries

are

covered

by

U.S.

and foreign

patents and/or

pending

patents.

TEKTRONIX,

TEK,

SCOPE-MOBILE,

and

are

registered

trademarks of

Tektronix, Inc.

TELEQUIPMENT

is

a

registered trademark

of Tektronix

U.K. Limited.

Printed in

U.S. A. Specification

and price

change privileges

are reserved.

INSTRUMENT

SERIAL NUMBERS

Each

instrument has

a

serial

number on

a panel insert,

tag,

or

stamped on the chassis. The

first number

or letter

designates the country of

manufacture.

The last five

digits

of the serial number are assigned

sequentially

and

are

unique

to

each instrument.

Those

manufactured

in the

United

States

have

six unique digits.

The country

of

manufacture is identified

as

follo\ws;

BOOOOOO

Tektronix, Inc.,

Beaverton, Oregon,

USA

100000 Tektronix Guernsey,

Ltd., Channel Islands

200000

Tektronix

United Kingdom,

Ltd., London

300000

Sony/Tektronix,

Japan

700000

Tektronix Holland,

NV, Heerenveen,

The Netherlands

7B10

Operators

TABLE

OF

CONTENTS

PAGE

LIST OF

ILLUSTRATIONS

j|

LIST

OF

TABLES

jj

OPERATORS

SAFETY

SUMMARY

ijj

SECTION

1 GENERAL

INFORMATION

INTRODUCTION

1_1

OPERATORS

MANUAL

M

INSTRUCTION

MANUAL

1-1

INSTALLATION

M

INSTRUMENT

PACKAGING

1-1

SPECIFICATION

1-2

STANDARD

ACCESSORIES

1-4

SECTION 2 OPERATING

INSTRUCTIONS

CONTROLS,

CONNECTORS

AND INDICATORS 2-1

OPERATORS

CHECKOUT

2-1

SETUP PROCEDURE

2-1

SWEEP

FUNCTIONS

2-1

TRIGGERING

FUNCTIONS

2-4

DETAILED

OPERATING

INFORMATION

2-4

TRIGGERING SWITCH

LOGIC

2-4

TRIGGERING

MODE

2-4

TRIGGERING COUPLING

2-5

TRIGGERING

SOURCE

2-5

TRIGGERING

SLOPE

2-7

TRIGGERING

LEVEL

2-7

HORIZONTAL

SWEEP RATES

2-7

TIME

MEASUREMENTS

2-7

SWEEP

MAGNIFICATION

2-8

VARIABLE

HOLD OFF

2-8

MAINFRAME

OPERATING

MODES

2-8

APPLICATIONS

2-8

TIME-INTERVAL

MEASUREMENTS

2-8

PERIOD

AND FREQUENCY

MEASUREMENTS

2-8

RISE-TIME

AND

FALL-TIME

MEASUREMENTS

2-9

PULSE

WIDTH

MEASUREMENTS

2-10

DELAYED-SWEEP

MEASUREMENTS

2-11

SECTION

3

INSTRUMENT

OPTIONS

CHANGE

INFORMATION

7B10

Operators

LIST

OF

ILLUSTRATIONS

FIGURE

NO.

page

Frontis-

piece

7B10

Features

iv

1-1

Location

of

release

latch

1-1

1-

2

7B10

dimensional

drawing

1-4

2-

1

Front-panel

controls,

connectors,

and

indicators

2-2

2-2

Effect

of

LEVEL

control

and

SLOPE

switch

on

crt

display

2-6

2-3

Area

of

graticule

used for

most

accurate

time

measurements

2-7

2-4

Operation

of

sweep

magnifier

2-8

2-5

Measuring

the

period

and

determing

the

frequency

of

a displayed

waveform

2-9

2-6

Measuring

the

rise time

and

fall

time

of

a

displayed

waveform

2-10

2-7

Measuring

the

pulse

width

of

a displayed

waveform

2-10

LIST

OF

TABLES

TABLE

NO-

PAGE

1-1

Electrical

Characteristics

1-2

1-2

Environmental

Characteristics

1-4

1-3

Physical

Characteristics

1-4

7B10

Operators

OPERATORS

SAFETY

SUMMARY

The

following

general safety

information

applies

to

all

operators

and

service

personnel.

Specific

warnings

and

cautions

will be found

throughout

the

manual

where

they

apply

and

should

be followed

in

each

instance.

WARNING

statements

identify

conditions

or

practices

which

could

result

in

personal

injury

or

loss of

life.

CAUTION

statements

identify

conditions

or

practices

which

could

result in

damage

to the

equipment

or

other

property.

WARNING

GROUND

THE

INSTRUMENT

To reduce

electrical-shock

hazard,

the

mainframe

(oscilloscope)

chassis

must

be properly

grounded.

Refer

to

the

mainframe

manual

for

grounding

information.

DO

NOT REMOVE

INSTRUMENT

COVERS

To

avoid

electric-shock

hazard,

operating

personnel

must

not

remove

the

protective

instrument

covers

Component

replacement

and

internal

adjustments

must

be

made

by

qualified

service

personnel

only.

DO

NOT

OPERATE

IN

EXPLOSIVE

ATMOSPHERE

To avoid

explosion,

do not

operate

this

instrument

in

an

explosive

atmosphere

unless

it

has

been

certified

for

such operation.

V

s

CAUTION

PREVENT

INSTRUMENT

DAMAGE

Plug-in

units should

not

be

installed

or

removed

without

first

turning

the

instrument

power

off, to

prevent

instrument

damage.

7B10 Operators

2416-1

7BIO

Features

The

7B10

Time-Base

unit provides

calibrated

sweep rates

from

.2

seconds to

2

nanoseconds

and triggering

to

1

gigahertz for 7100-,

77CX3-, 7800-, and

79CXD-series

oscilloscopes.

A

X10 Magnifier

increases each

sweep

rate

by a

factor of

10 and a

VARIABLE

TIME/DIV

control

provides

continuously

variable

sweep rates

between calibrated

steps.

Variable

hold off

and alpha-numeric

readout are

provided.

Also,

when

operating in the

AUTO TRIGGERING

MODE, a

bright baseline

trace

is displayed in

the absence

of

a

trigger

signal.

The

7B10 can be operated

as an independent time

base or as a delayed-sweep unit

with

a companion delaying

time-base

unit.

!V

Section

1

—7B10

Operators

GENERAL

INFORMATION

INTRODUCTION

OPERATORS

MANUAL

The

Operators

Manual

contains

information

necessary

to

effectively

operate

the

7B10

Time

Base

and is

divided

into

three

sections:

Section

1

provides

a basic

description

of the

7B10

with

instrument

specifications

and

accessories,

section

2 contains

operating

information

for

the

instrument,

Instrument

Option

information

is

located

in

section

3

of

the

manual.

INSTRUCTION

MANUAL

The

Instruction

Manual

provides

both

operating

and

servicing

information

for

the

7B10

Time

Base.

The

Instruction

Manual

is

divided

into

nine

sections.

Operating

information

is

covered in

the

first

two

sections;

servicing

information

for

use by

qualified

service

personnel

is

contained

in the

remaining

seven

sections

of

the

manual.

Schematic

diagrams

are

located

at the

rear

of the

manual

and

can be

unfolded

for

reference

while

reading

other

parts

of

the

manual.

The

reference

designators

and

symbols

used

on

the

schematics

are

defined

on the first

page of

the

Diagrams

and

Circuit

Board

Illustrations

section.

All

abbreviations

used

in

this

manual,

with

the

exception

of the

parts

list

and

schematic

diagrams,

comply

with

the

American

National

Institute

Y1.

1-1

972

publication.

The

parts

lists

are

computer

printouts

and

use

computer-supplied

abbreviations.

Instrument

Option

information

is

located

in

section

6 of

the

Instruction

Manual.

INSTALLATION

The

time-base

unit

is

designed

to

operate

in

the

horizontal plug-in

compartment

of

the

mainframe.

This

instrument

can

also

be

installed

in

a vertical

plug-in

compartment

to provide

a vertical

sweep

on

the

crt.

However,

when

used

in

this

manner,

there

are

no

internal

triggering

or

retrace

blanking

provisions,

and the

unit may

not meet

specifications.

To

install

the unit

in

a plug-in

compartment,

push

it in

until it

fits firmly

into

the

compartment.

The

front

panel

of

the unit

should

be

flush

with

the

front

panel

of the

mainframe.

Even

though

the

gain of

the

mainframe

is

standardized,

the sweep

calibration

of the

unit

should

be

checked

when

installed.

The

procedure

for

checking

the

unit is

given

under

Sweep

Functions

in

the

Operators

Checkout

procedure

in

section

2.

To remove

the unit,

pull

the

release

latch

(see Fig.

1 -1

)

to

disengage the

unit

from the

mainframe,

and

pull it

out of

the plug-in

compartment.

INSTRUMENT

PACKAGING

If this

instrument

is

to be

shipped

for

long

distances

by

commercial

means

of

transportation,

it

is

recommended

that

it

be

repackaged

in

the

original

manner

for

maximum

protection.

The

original

shipping

carton

can

be

saved

and

used

for

this

purpose. If

more

information

is

needed,

contact

your

local

Tektronix

Field

Office

or

representative.

Fig. 1-1.

Location

of

release

latch.

1-1

General

Information—

7B10

Operators

SPECIFICATION

This instrument will meet the

electrical

characteristics

listed

in

Table 1 -1,

following

complete

adjustment. The following

electrical characteristics

are valid

over

the

stated

environmental

range

for instruments

calibrated

at an ambient

temperature

of

+20°

to

+30°

C, and after

a

twenty-minute

warmup

unless otherwise

noted.

TABLE

1-1

Electrical

Characteristics

Characteristics

Performance Requirement

SWEEP

GENERATOR

Sweep Rates

Calibrated Range

0.2 s/div

to 2 ns/div in

25 steps, XI

0

Magnifier extends

fastest calibrated

sweep rate

to 0.2 ns/div.

Variable Range

Continuously

variable uncalibrated

sweep

rate

to at

least

2.5

times the calibrated

sweep rate setting.

Sweep Accuracy^ with

7104, 7900 and

7800 Series Mainframes

+15°

to

+35°

C

0.2 s/div to 10 ns/div

5

ns/div and 2

ns/div

Measured over center

8

displayed

divisions.

^

SWP

CAL

is adjusted

at

1 ms/div within

the

+20°

to

+30°

C range.

UNMAG

MAG

XI

0

2%

3%

3%

4%^

0°

to

+50°

C

Derate

+15°to+35°

C

accuracy by

additional

1%.

Excluded Portions

of Sweep

7104

7800, 7900

Series

None.

First

5 ns.

Sweep Length

At

least

10.2 div.

MAG Registration

0.5 div or

less from graticule

center when changing

from

MAG

XI

0 to

MAG XI.

Position Range

POSITION Controls fully cw

Start

of sweep

must be to

right of graticule center at

1 ms/div.

POSITION Controls fully ccw

End of

sweep must

be

left of graticule center at 1

ms/div.

’Some mainframes

limit fastest calibrated

sweep rate.

^200

ps/div

is measured over any

5 divisions withir.

the center

8 divisions.

1-2

REV MAY 1981

General

Information—

7B10

Operators

TABLE 1-1

(CONT.)

Electrical

Characteristics

Characteristic

Performance

Requirement

TRIGGERING

Trigger Sensitivity for

Repetitive

Signals

Triggering

Frequency

Minimum Triggering

Range®

Signal Required

Coupling

Internal

External

AC

30 Hz

to 250 MHz

0.5 div

50 mV

250

MHz

to 1

GHz

1 .5 div

150 mV

AC

LF REJ'’

50 kHz

to 250

MHz

0.5 div

50 mV

250 MHz

to 1 GHz

1

.5 div

150 mV

AC HF

REJ

30

Hz

to

30

kHz

0.5 div

50

mV

DC®

DC

to 250

MHz

0.5

div

50 mV

250 MHz

to 1 GHz

1.5 div

150

mV

Single Sweep

Same

as

for

Repetitive

Triggering,

Internal Trigger

Jitter

30

ps

or

less

at 1 GHz.

Operating in HF

SYNC MODE

AC,

AC LF REJ,

or DC

250

MHz

to 1

GHz-0.3

div.

Internal

75

mV

External.

External

Trigger Input

LEVEL RANGE

At

least

±3,5

V

(checked

on 1

kHz

sine

wave).

Maximum

Safe Input

1

-Megohm

Input

250

V

(dc plus

peak

ac).

50-0hm Input

1

Watt

average.

Input R and

C

1

-Megohm Input

1 MQ

within

5%,

20

pF

within

10%.

50-0hm

50 Q within

2%.

Trigger

Holdoff

Time

Minimum

Holdoff

Setting

0.2

s/div

to 50 ms/div

40

ms,

or less

20 ms/div

to

2

^(s/div

2 times

TIME/DIV

setting,

or less

1

yus/div

to 2 ns/div

2.0

IIS,

or less

Maximum

Holdoff

Setting

0.2 s/div

to 50 ms/div

400

ms, or

greater

20 ms/div

to

2

yus/div 20

times

TIME/DIV

setting,

or

greater

1

/fs/div

to

0.5

yus/div

20.0

IIS,

or

greater

0.2

yUs/div

to 2 ns/div

6.0

ns,

or

greater

=The triggering

frequency

ranges

given here

are

limited

to the

-3

dB

frequency

of the

oscilloscope

vertical

system

when

operating

in

the Internal

mode.

^Will

not trigger on sine

waves

at or

below

60 Hz

when

amplitudes

are

less

than 8

divisions

Internal

or

3 volts

External.

The triggering

frequency

range

for

DC COUPLING

applies

to

frequencies

above

30

Hz when

operating

in the

AUTO

TRIGGERING

MODE.

REV

MAY

1981

1-3

General

Information

—7B10

Operators

TABLE

1-2

Environmental

Characteristics

Refer

to the

Specification

section

of

the

associated

mainframe

manual.

TABLE

1-3

Physical

Characteristics

Characteristic

Information

Net

Weight

Approximately

2.6 pounds

(1.2 kilogram).

Dimensions

See

Figure

1-2,

dimensional

drawing.

STANDARD

ACCESSORIES

Operators Manual

Instruction

Manual

OVERALL

DIMENSIONS

(MEASURED

AT

MAXIMUM

POINTS)

NOTE:

TOP

FIGURES

IN

INCHES

LOWER

FIGURES

IN

CENTIMETERS

c 1985-5

Fig.

1-2.

7B10

dimensional

drawing.

1-4

Section

2—

7B10

Operators

OPERATING

INSTRUCTIONS

The

7B10 Time-Base

unit

operates

with

a Tektronix

7100,

7700,

7800,

or

7900-series

oscilloscope

mainframe

and

a 7A-

series amplifier

unit

to form

a

complete

oscilloscope

system.

This

section

describes

the

operation

of

the front-panel

controls and

connectors,

provides

detailed

operating

information,

an

operators

checkout

procedure,

and

basic

applications

for

this

instrument.

CONTROLS,

CONNECTORS,

AND

INDICATORS

All controls,

connectors,

and indicators

required

for

the

operation of the

time-base

unit

are

located

on the

front

panel. Figure 2-1

provides

a brief

description

of

all

front-

panel

controls,

connectors,

and

indicators.

More

detailed

information

is

given in

the

Detailed

Operating

Information.

OPERATORS

CHECKOUT

The following

procedures

are provided

for

checking

basic

instrument

functions.

Refer

to the

description

of the

controls,

connectors,

and

indicators

while

performing

this

procedure. If

performing

the

operators

checkout

procedure

reveals

a malfunction

or

possible

maladjustment,

first

check

the

operation

of

the

associated

plug-in

units, then

refer

to the

instruction

manual for

maintenance

and

adjustment

procedures.

SETUP

PROCEDURE

1.

Install

the

time-base

unit

being

checked

in

the

A

horizontal

compartment

of

the

mainframe.

2. Install

an

amplifier

plug-in

unit

in

a

vertical

compartment.

3. Set

the

time-base

unit

controls

as

follows:

SLOPE

(+)

mode

auto

COUPLING

AC

SOURCE

INT

POSITION

Midrange

TIME/DIV

1

ms

VARIABLE

(CAL IN)

Calibrated

(Pushed

in)

HOLD

OFF

min

(fully

counterclockwise)

mag

XI

(pushed

in)

EXT

TRIG IN

OUT

50

O

4. Turn

on the

mainframe

and

allow

at

least 20

minutes

warmup.

5. Set

the mainframe

vertical

and

horizontal

modes

to

display

the

plug-in

units

used and

adjust

the

intensity

and

focus for

a

well-defined

display.

See

the

oscilloscope

mainframe

and

amplifier

unit

instruction

manuals

for

detailed

operating

instructions.

SWEEP

FUNCTIONS

Normal

Sweep

Perform

the

following

procedure

to

obtain

a

normal

sweep

and

to demonstrate

the

function

of

the

related

controls:

1 . Perform

the

preceding

Setup

Procedure.

2.

Connect

a

0.4-volt,

1

-kilohertz

signal

from

the

mainframe

calibrator

to

the

amplifier

unit

input.

3.

Set the amplifier

unit deflection

factor

for

4

divisions

of

display.

4. Adjust

the LEVEL

control

for

a

stable

display,

5. Turn

the

POSITION

control

and

note

that

the

trace

moves

horizontally.

6.

Turn the

FINE

control

and

note

that

the

display

can

be

precisely

positioned

horizontally.

7.

Check the

display

for

one

complete

cycle

per

division.

If

necessary,

adjust the

front-panel

SWP

CAL

screwdriver

adjustment

for

one

complete

cycle

per

division

over

the

center

8

graticule

divisions.

Be sure

that

the

timing

of

the

mainframe

calibrator

signal

is

accurate

to within

0 25%

(+20°

to

+ 30°

C).

8.

Press to

release

the

VARIABLE

(CAL

IN)

control.

Turn

the VARIABLE

(CAL

IN)

control

fully

counterclockwise

and

note

that

the

displayed

sweep

rate

changes

to

at

least the

next

slower

TIME/DIV

switch

setting

(i.e.,

2

milliseconds/division).

Press

the

VARIABLE

(CAL IN)

knob

in

to the

calibrated

position.

Magnified

Sweep

Perform

the

following

procedure

to

obtain

a XI

0

magnified

display

and

to

demonstrate

the

function

of

the

related

controls:

1.

Obtain

a one

cycle

per

division

display

as

described

in

the

preceding

Normal

Sweep

procedure.

2.

Press

to release

the

MAG

button

(XI

0).

Note

that

the

unmagnified

display

within

the

center

division

of the

graticule

is

magnified

to

about

10

divisions.

3.

Press

the

MAG

button

(XI

).

2-1

Operating

Instructions—

7B10

Operators

©©©©©©©

©©©©

©©

©

©@

Operating Instructions—7B

10

Operators

TRIGGERING

LEVEL Control—

Selects a point

on the trigger

signal

where

triggering

occurs.

SLOPE

Switch Permits

sweep to be triggered

on negative

or

positive-going

portions

of the trigger signal.

READY

Indicator—

Illuminates

when sweep

circuit is

armed

(SINGLE

SWP Mode).

TRIG'D Indicator—

Illuminates

when the display

is

triggered.

MODE

Pushbuttons—

Selects the

operating mode

of the

triggering

circuit.

COUPLING

Pushbuttons—

Selects the

method of

coupling

the trigger

signal

to triggering

circuit.

SOURCE

Pushbuttons—Selects

source

of the trigger

signal.

SWEEP

POSITION Control

—Provides

horizontal

positioning.

FINE

Control—Provides

precise horizontal

positioning.

MAG

Pushbutton—Selects

magnified

X10 or

unmagnified

sweep.

HOLD OFF Control—

Permits hold

off period

to bo

varied

to improve

trigger

stability

on repetitive

complex

waveforms.

TIME/DIV

Selector—

Selects the

sweep

rate of

the sweep

generator.

VARIABLE

Control and

CAL Switch—

Selects

calibrated

or

uncalibrated

sweep

rates.

Uncalibrated

sweep

rates

can

be continuously

reduced

to at

least the

sweep rate

of

the next

slower

position.

SWP CAL

Adjustment—

Compensates for

basic

timing

changes

duo to

the

differences

in

sensitivity

of

mainframes.

EXTERNAL

TRIGGER

INPUT

EXT TRIG

Button—Selects

input

impedance.

EXT TRIG IN

Connector—

Connector

(BNC

type)

provides

input

for

external

trigger

signals.

2317-03

Fig. 2-1

(cont.). Front-panel

controls,

connectors,

and indicators.

Operating Instructions—

7B10

Operators

TRIGGERING

FUNCTIONS

Perform

the

following

procedure

to obtain

a

triggered

sweep

and

to

demonstrate

the

functions

of the

related

controls:

1.

Obtain

a display

as

described

in

the

preceding

Normal

Sweep

procedure.

2. Turn

the

LEVEL

control

fully

counterclockwise

to

obtain

a free-running

sweep.

3.

Slowly

turn

the

HOLD

OFF

control

clockwise

and

note

that

a stable

display

can

be

obtained

at several

positions

of the

HOLD

OFF

control.

Return

the

HOLD

OFF

control

to the

fully

counterclockwise

(MIN)

position.

NOTE

The

HOLD

OFF

control

varies

the

sweep

hold-

off

time

which

effectively

changes

the

repetition-rate

of the

horizontal

sweep

signal.

However,

Its

primary

function

is

to

obtain

a

stable display

of

complex

waveforms

which

are

otherwise

difficult

to

trigger.

4.

Press the

AC,

AC HF

REJ,

and

DC

COUPLING

buttons

for

both the

+

and

-

positions

of

the

SLOPE

switch

and

check

for

a stable

display

(LEVEL

control

may

be

adjusted,

if

necessary,

to

obtain

a

stable

display).

5. Apply

the

0.4-volt,

1

kilohertz

signal

from

the

mainframe

calibrator

to the

amplifier

unit

and

to the

EXT

TRIG

IN

connector,

6. Press

the EXT

SOURCE

button

and

set the

amplifier

unit

deflection

factor

for

a

4-division

display.

7.

Press the

AC, AC

HF REJ,

and DC

COUPLING

buttons

for both

the

+

and

-

positions

of

the

SLOPE

switch

and

check for

a

stable

display

(LEVEL

control

may

be

adjusted, if

necessary).

8.

Press the

AC

COUPLING,

INT

SOURCE,

and

NORM

MODE

buttons.

Adjust the

LEVEL

control

for

a

stable

display.

9.

Press the

AUTO

MODE

button

and

adjust the

LEVEL

control for

a free-running

display.

10.

Press the

NORM

MODE

button

and

check

for

no

display.

1

1 . Adjust

the LEVEL

control

for

a stable

display

and

press the

SINGLE

SWP

MODE

button.

12.

Note

that one

trace

occurs

when

the

SINGLE

SWP

button

is

pressed

again.

13.

Disconnect the

mainframe

calibrator

signal

from

the

amplifier unit

input

and

press

the

SINGLE

SWP

button.

Check

for no

display

and note

that

the READY

indicator

is

lit.

14.

Note that

one

trace

occurs

and

that

the

READY

indicator

extinguishes

when

the

mainframe

calibrator

signal is

reconnected

to the

amplifier

unit

input.

DETAILED

OPERATING

INFORMATION

TRIGGERING

SWITCH

LOGIC

The

MODE, COUPLING,

and

SOURCE

push

buttons

of the

TRIGGERING

switches

are arranged

in

a

sequence which

places the most-often

used

position

at the

top of

each

vertical

row of

push buttons.

With

this

arrangement,

a

stable display

can usually

be obtained

by pressing

the

top

push

buttons:

AUTO, AC, INT.

When

an

adequate

trigger

signal

is

applied and the

LEVEL

control

is

correctly

set,

the unit is

triggered

as indicated

by the

illuminated

TRIG'D

light. If

the TRIG'D

light

is not

on, the

LEVEL

control is either

at

a

setting

outside the

range

of

the

trigger signal

applied

to this unit

from

the vertical

unit,

the trigger

signal

amplitude

is

inadequate,

or its

frequency

is

below the lower

frequency

limit

of

the AC

COUPLING

switch position.

If the

desired

display

is

not

obtained with

these buttons

pushed

in,

other

selections

must

be made. Refer

to the following

discussions

or the

instruction

manuals for

the

associated

oscilloscope

mainframe

and vertical

unit(s)

for more

information.

TRIGGERING

MODE

The MODE

push-button

switches

select the

mode

in

which

the

sweep is triggered.

Auto

The

AUTO MODE provides

a

triggered

display

with

the

correct setting of

the LEVEL

control

whenever

an

adequate trigger

signal

is applied

(see Trigger

Level

discussions).

The TRIG'D

light

indicates

when

the

display

is triggered.

When the trigger

repetition

rate

is outside

the

frequency

range

selected

by

the

COUPLING

switch or

the

trigger

signal

is inadequate,

the sweep

free

runs

at the

rate

indicated

by the TIME/DIV

switch

(TRIG'D

indicator

off).

An adequate trigger

signal

ends the

free-running

condition and

a

triggered

display is

presented.

The

sweep

also free

runs

at the rate

indicated

by the

TIME/DIV

switch when

the LEVEL

control

is

at a setting

outside

the

amplitude range of

the

trigger signal.

This

type of

free-

running display

is useful

when it

is desired

to

measure

only the

peak-to-peak

amplitude

of

a

signal

without

observing

the

waveshape

(such

as

bandwidth

measurements),

HF

Sync

The HF

SYNC mode

provides

a triggered

display

with

the

correct setting

of the LEVEL

control

whenever

a high

frequency,

(100

MHz or higher)

low

amplitude

signal

is

applied. This

mode is useful when

the

incoming

signal

is

too small

to

produce

stable triggering

in the

AUTO

or

NORMAL

modes. The HF

SYNC

mode

increases

trigger

sensitivity and

provides

automatic

trigger

amplifier

centering

for optimum

triggering

under

these

conditions.

Operating

Instructions—

7B10

Operators

Normal

The NORM

MODE

provides

a

triggered

display

with

the

correct

settings of

the LEVEL

control

whenever

an

adequate trigger

signal

is

applied.

The

TRIG'D

light

indicates when

the

display

is

triggered.

The

normal

trigger

mode

must

be

used

to

produce

triggered

displays

with

trigger

repetition

rates

below

about

30

hertz.

When

the

TRIG'D

light

is off,

no

trace

is

displayed.

Single

Sweep

When

the signal

to be

displayed

is not

repetitive

or

varies

in

amplitude,

waveshape,

or

repetition

rate,

a

conventional

repetitive

type

display

may

produce

an

unstable

presentation.

Under

these

circumstances,

a

stable

display can

often

be obtained

by using

the

single-

sweep

feature of

this

unit. The

single-sweep

mode

is

also

useful

to photograph

non-repetitive

or

unstable

displays.

To

obtain

a single-sweep

display

of

a

repetitive

signal,

first

obtain the

best

possible

display in

the

NORM

MODE.

Then, without

changing

the

other

TRIGGERING

controls,

press the SINGLE

SWP RESET

button.

A

single

trace

is

presented

each time

this

button

is

pressed.

Further

sweeps

cannot

be

presented

until

the

SINGLE

SWP

RESET

button

is

pressed

again. If

the

displayed

signal

is

a

complex

waveform

composed

of varying

amplitude

pulses,

successive

single-sweep

displays

may

not

start

at

the

same point

on the

waveform.

To

avoid

confusion

due

to

the crt

persistence,

allow the

display

to

disappear

before

pressing

the

SINGLE

SWP

RESET

button

again.

At

fast

sweep

rates, it

may

be difficult

to view

the

single-

sweep

display.

The

apparent

trace

intensity

can

be

increased

by

reducing

the

ambient

light level

or by

using

a viewing

hood

as

recommended

in the

mainframe

instruction

manual.

When using

the

single-sweep

mode

to

photograph

waveforms,

the

graticule

may have

to be

photographed

separately

in the

normal

manner

to

prevent

over

exposing

the

film.

Be sure

the

camera

system

is

well

protected

against stray

light,

or

operate

the

system

in

a

darkened

room.

For

repetitive

waveforms,

press the

SINGLE

SWP RESET

button

only

once

for

each

waveform

unless

the signal

is

completely

symmetrical.

Otherwise,

multiple

waveforms

may

appear

on the

film.

For

random

signals, the

lens

can

be left

open until

the

signal

triggers

the unit.

Further

information

on

photographic

techniques

is given

in

the

appropriate

camera

instruction

manual.

TRIGGERING

COUPLING

The

TRIGGERING

COUPLING

push

buttons

select

the

method

in which

the

trigger

signal

is

connected

to

the

trigger

circuits.

Each

position

permits

selection

or

rejection

of

some

frequency

components

of

the

signal

which

triggers

the

sweep.

AC

AC

COUPLING

blocks

the

dc

component

of

the

trigger

signal.

Signals

with

low-frequency

components

below

about

30 hertz

are

attenuated.

In

general,

AC

COUPLING

can

be used

for most

applications.

However,

if

the

signal

contains

unwanted

frequency

components

or if

the

sweep

is

to be

triggered

at a low

repetition

rate

or

dc

level,

one of

the other

COUPLING

switch

positions

will

provide

a better

display.

AC LF

REJ

AC LF

REJ

COUPLING

rejects

dc,

and

attenuates

low-

frequency

trigger

signals

below

about

50

kilohertz.

Therefore,

the

sweep is

triggered

only

by the

higher-

frequency

components

of the

trigger

signal.

This

position

is

particularly

useful

for

providing

stable

triggering

if the

trigger

signal

contains

line-frequency

components.

Also,

the

AC LF

REJ

position

provides

the

best

alternate-mode

vertical

displays

at fast

sweep

rates

when

comparing

two

or more

unrelated

signals.

AC HF

REJ

AC HF

REJ

COUPLING

passes

all

low-frequency

signals

between

about

30 hertz

and

30

kilohertz.

Dc is

rejected

and

signals

outside

the

above

range

are

attenuated.

When

triggering

from

complex

waveforms,

this

position

is

useful

to provide

a

stable

display

of

the

low-frequency

components.

DC

DC

COUPLING

can

be

used

to

provide

stable

triggering

from

low-frequency

signals

which

would

be

attenuated

in

the

other

COUPLING

switch

positions.

DC

COUPLING

can

be

used to

trigger

the

sweep

when

the

trigger

signal

reaches

a dc

level

set

by the

LEVEL

control.

When

using

internal

triggering,

the

setting

of

the

vertical

unit

position

control

affects

the

triggering

point.

TRIGGERING

SOURCE

The

TRIGGERING

SOURCE

push

buttons

select

the

source

of

the

trigger

signal

which

is

connected

to

the

trigger

circuits.

Internal

The

INT

position

connects

the

trigger

signal

from

the

vertical

plug-in

unit.

Further

selection

of

the

internal

trigger

signal

may

be

provided

by

the

vertical

plug-in

unit

or

by the

mainframe;

see

the

instruction

manuals

for

these

instruments

for

more

information.

For

most

applications,

the

internal

source

can

be

used.

However,

some

applications

require

special

triggering

which

cannot

be

obtained

in

the INT

position.

In

such

cases,

the

LINE

or

EXT

positions

of

the

SOURCE

switches

must

be

used.

Line

The

LINE

position

connects

a

sample

of

the

power-line

voltage

from

the

mainframe

to the

trigger

circuit.

Line

triggering

is

useful

when

the

input

signal

is

time-related

(multiple

or

submultiple)

to

the line

frequency.

It

is

also

useful

for

providing

a

stable

display

of

a

line-frequency

component

in

a

complex

waveform.

Operating

Instructions—

7B

10

Operators

CRT

DISPLAY

OBTAINED

WITH

SLOPE

SWITCH

SET TO

POSITIVE

(+)

TMG'O

LEVEL

W

TRIG'O

LEVEL W

CRT DISPLAY

OBTAINED

WITH

SLOPE

SWITCH

SET

TO

NEGATIVE

(-)

TRIG'O

S(L©(Pll

LEVEL W

Cl qfin-nn

Fig,

2-2.

Effect

of

LEVEL

control

and

SLOPE switch

on crt display.

External

The EXT

position

connects the

signal

from the

EXT

TRIG

IN

connector

to

the

trigger

circuit.

The

external

signal

must

be time-related

to the

displayed

waveform

for

a

stable display.

An external

trigger

signal

can

be

used

to

provide

a

triggered

display

when

the

internal

signal

is

either

too low in

amplitude

for

correct

triggering

or

contains signal

components

on which

triggering

is

not

desired.

It is

also

useful when

signal

tracing

in

amplifiers,

phase-shift

networks,

wave-shaping

circuits,

etc. The signal from

a single

point in

the

circuit

can

be

connected

to the EXT

TRIG IN

connector

through

a probe

or cable. The

sweep

is then triggered

by the

same

signal

at all times

and allows

amplitude,

time

relationship,

or

waveshape

changes of

signals

at various

points in

the

circuit

to be examined

without

resetting

the

TRIGGERING

controls.

The IN

1 Mn/OUT

50

Q

pushbutton

provides

a

convenient

means of

selecting

external-trigger

input

impedance. Pushing

the button

in

sets the

amplifier

input

impedance

to 1 MQ and

the OUT

position

provides

50 Q

input impedance.

Operating

Instructions—

7B10

Operators

HORIZONTAL

SWEEP

RATES

The TIME/DIV

switch

provides

calibrated

sweep

rates

from .2

seconds/division

to 2

nanosecond/division

in

a

1-2-5

sequence. The

VARIABLE

TIME/DIV

control

must

be in the

calibrated

position

and the

MAG

switch

set to

XI

to obtain the

sweep

rate

indicated

by

the TIME/DIV

switch.

However,

the

mainframe

crt

readout

will

display

the

appropriate

sweep

rate.

The VARIABLE

TIME/DIV

control

includes

a

two-position

switch

to determine

if the

sweep

rate is

calibrated,

or

uncalibrated.

When the

VARIABLE

control is

pressed

in,

it

is

inoperative

and the

sweep

rate is

calibrated.

When

pressed and

released

outward,

the

VARIABLE

control

is

activated

for

uncalibrated

sweep

rates,

to at

least

the

sweep rate

of

the next

slower

position.

A calibrated

sweep rate

can

be

obtained

in any

position

of

the VARIABLE

control

by

pressing

in the

VARIABLE

control. This

feature is

particularly

useful

when

a

specific

uncalibrated

sweep rate

has

been

obtained

and

it is

desired

to switch

between

calibrated

and

uncalibrated

displays.

TRIGGERING

SLOPE

TIME

MEASUREMENTS

The

TRIGGERING

SLOPE

switch

(concentric

with

the

TRIGGERING

LEVEL

control)

determines

whether

the

trigger

circuit responds

on the

positive- or

negative-going

portion of the

trigger

signal.

When the

SLOPE

switch

is

in

the

(+)

(positive-going)

position,

display

starts

on

the

positive-going

portion of

the

waveform

(see Figure

2-2).

When

several cycles of

a signal

appear

on the

display

the

setting of the

SLOPE

switch

is often

unimportant.

However, if only

a certain

portion

of

a cycle

is

to be

displayed,

correct

setting

of the

SLOPE

switch

is

important

to provide

a display that

starts

on the

desired

slope

of the input

signal.

TRIGGERING

LEVEL

The TRIGGERING

LEVEL

control

determines

the

voltage

level on the

trigger

signal

at which

the

sweep

is

triggered.

When

the LEVEL

control is

set in

the

+

region,

the trigger

circuit

responds

at a more

positive

point

on

the trigger

signal.

When

the

LEVEL

control

is

set in

the

-

region,

the

trigger

circuit

responds

at

a more

negative

point on

the trigger

signal.

Figure

2-2

illustrates

this

effect

with

different

settings

of the

SLOPE

switch.

To

set

the

LEVEL

control,

first

select

the

TRIGGERING

MODE,

COUPLING,

SOURCE, and

SLOPE.

Then

set the

LEVEL

control

fully

counterclockwise

and

rotate

it

clockwise until

the

display

starts

at the

desired

point.

In

the

HF SYNC

mode,

the trigger

LEVEL

control

varies

the

sensitivity

of the

Trigger

Generator.

The

LEVEL

control is

set to

provide

a stable

display.

When

making

time

measurements

from

the

graticule,

the

area

between the

second

and

tenth

vertical

lines

of

the

graticule

provides

the

most linear

time

measurements

(see Fig. 2-3).

Position

the

start

of the

timing

area

to the

second

vertical line

and

adjust

the TIME/DIV

switch

so

the

end of the timing

area

falls

between

the

second

and

tenth

vertical

lines.

SECOND-VERTICAL

TENTH-VERTICAL

LINE

line

I

I

'

;

^

1

H

1

•

i

I

H

time

measurement

AREA

C

1752-06

Fig. 2-3.

Area

of graticule

used

for

most

accurate

time

measurements.

2-7

Operating

Instructions—

7B

10 Operators

SWEEP

MAGNIFICATION

The

sweep magnifier

can be

used

to expand

the

display

be

a factor of

10. The

center

division

of the

unmagnified

display is

the

portion

visible

on the

crt

in the

magnified

form

(see Fig. 2-4).

The

equivalent

length

of

the

magnified

sweep

is more

than

100

divisions;

any

10

division

portion

can

be viewed

by

adjusting

the

POSITION

and FINE

POSITION

controls

to

bring

the

desired

portion

into

the

viewing

area.

When

the

MAG

switch

is

set

to

XI

0

(OUT)

the

equivalent

magnified

sweep

rate

can be

determined

by dividing

the

TIME/DIV

setting

by

10;

the

equivalent

magnified

sweep

rate is

displayed

on

the

crt

readout.

VARIABLE

HOLD

OFF

The

HOLD

OFF

control

improves

triggering

stability

on

repetitive

complex

waveforms

by effectively

changing

the

repetition rate

of the

horizontal

sweep

signal.

The

HOLD

OFF

control

should

normally

be

set

to its

minimum

setting.

When

a stable

display

cannot

be

obtained

with

the

TRIGGERING

LEVEL

control, the

HOLD

OFF

control

can

be

carried for

an

improved

display.

If

a

stable

display

cannot

be obtained

at any

setting of

the

LEVEL

and

HOLD OFF

controls,

check

the

TRIGGERING

COUPLING

and

source

switch

settings.

1

1

ms

JISPLAY

LAY

—

F-\

-

-

\

\

u^ MACiNIF

ED C

\

\

'

r

\

““

i

t

/

\

\

MAG-X1

/

1 1

\

\

7

!

\

\

/

/

i

too

MS

\

\

i

/

/

T

V

\

/

/

\

i

/

—

/

/

4—

MAGNIF

MED

DISP

im

Ill

C

1960-16

Fig.

2-4.

Operation

of

sweep

magnifier.

MAINFRAME

OPERATING

MODES

The

time-base

unit

can

be

operated

either

as an

independent

time

base

in any

Tektronix

7100-,

7700-,

7800-,

or

7900-series

oscilloscope

mainframes,

or

as

a

delayed-sweep

unit in

those

mainframes

that

have

two

horizontal

compartments.

A

companion

delaying

time

base unit is

required

for

delayed-sweep

operation.

Refer

to

the

delaying

time-base

unit

instruction

manual

for

additional

information.

APPLICATIONS

The

following information

describes

procedures

and

techniques for making

basic time

measurements

with

the

time-base

unit installed

in

a

Tektronix

7100,

7700, 7600,

or 7900-series

oscilloscope.

These

procedures

provide

enough detail

to

enable

the

operator

to adapt

them

to

other

related time

measurements.

Contact

your

Tektronix

Field

Office or

representative

for

assistance in

making

measurements

that are

not described

in

this manual.

TIME-INTERVAL

MEASUREMENTS

Since time

is a function

of the

sweep rate

and

the

horizontal

distance

(in divisions)

that the

sweep

travels

across

the graticule

in a

calibrated-sweep

oscilloscope

system,

the time interval

between

any two

points

on

a

waveform

can be accurately

measured.

The

following

procedures

provide methods

to

measure some

of

the

more

common

time-related

definable

characteristics

of

a

waveform

such

as period,

frequency,

rise

time, fall

time,

and pulse

width.

The

procedure for

each of

these

measurements

is

essentially the

same,

except

for the

points

between which

the

measurements

are made.

The

time interval

between

any

two

selected

points

on a

displayed

waveform

can

be measured

with

basically

the

same

technique.

PERIOD

AND

FREQUENCY

MEASUREMENTS

Perform the following

procedure

to measure

the

period

and

determine the

frequency

of

a

displayed

waveform:

1. Install

the

time-base unit

in

a mainframe

horizontal

compartment

(either A

or

B horizontal

in

a four-

compartment

mainframe).

2. Connect

the signal

to be

measured

to the

vertical

unit

input.

3.

Set the

mainframe

horizontal-

and

vertical-mode

switches

to display

the time

base

and vertical

units.

(Check that

the time

base VARIABLE

(CAL IN)

control

is

pushed in

and the

HOLD OFF

control

is in

the

MIN

position.)

4.

Set the TRIGGERING

switches and

LEVEL

control

for

a

stable display

(see General

Operating

Information

for

selecting

proper triggering).

Operating

Instructions—

7B

10

Operators

Fig.

2-5.

Measuring

the period

and

determining

the

frequency

of a displayed

waveform.

5.

Set the vertical

deflection

factor

and

position

control

for

about

a 5-division

display,

vertically

centered

on

the

graticule.

6. Set the TIME/DIV

switch

and

POSITION

controls

for

a

complete

cycle

displayed

within

the

center

8

graticule

divisions

as

shown in

Figure

2-5.

7. Measure

the

horizontal

distance

in

divisions

over

1

complete cycle

of the

displayed

waveform.

Using the

formula:

1

Frequency

=

—

\

—

period

Substituting

values:

1

Frequency

=

—

=

1.43

kilohertz

0.7 ms

RISE-TIME

AND

FALL-TIME

MEASUREMENTS

Perform

the following

procedure

to

measure

the

rise

time

and fall time

of

a displayed

waveform:

1. Install the

time-base

unit

in

a

mainframe

horizontal

compartment

(either

A or

B

horizontal

in

a four-

compartment

mainframe).

2.

Connect the

signal

to be

measured

to the

vertical

unit

input.

3.

Set the mainframe

horizontal-

and

vertical-mode

switches

to display

the time

base and

the

vertical

unit.

(Check that

the time

base

VARIABLE

(CAL

IN)

control

is

pushed in and

the

HOLD

OFF

control

is

in

the

MIN

position.)

4. Set the

TRIGGERING

switches

and

LEVEL

control

for

a

stable display

(see

General

Operating

Information

for

selecting

proper triggering).

5.

Set the vertical

deflection

factor

and

position

controls

for

a

vertically-centered

display

with

an

exact

number

of

divisions of

amplitude.

8.

Multiply the

horizontal

distance

measured

in

Step

7

by

the TIME/DIV

switch

setting.

(Divide

the

answer

by

10 if

sweep

magnification

is

used.)

Example:

Assume

that

the

horizontal

distance

over

1

complete

cycle is

7 divisions,

and the

TIME/DIV

switch

setting

is .1

ms

(see Fig. 2-5).

Using

the formula:

Horizontal

TIME/DIV

Period

=

distance

x

setting

Magnification

Substituting

values:

Period

=

-

^

=

0.7 millisecond

1

9.

Determine

the

frequency

of

the

displayed

waveform

obtained

in

steps 1

through

8

by taking

the

reciprocal

of

the

period

of

1 cycle.

Example:

Assume

that

the

period

of

the

displayed

waveform

is 0.7

millisecond.

6.

Set the TIME/DIV

switch

and

POSITION

control

to

display

the

rising

or falling

portion

of the

waveform

within

the center

8

graticule

divisions

as shown

in

Figure

2-6

(see General

Operating

Information

in

this

section

for

discussion of

timing

measurement

accuracy).

7. Determine

rise

time or

fall

time

by

measuring

the

horizontal

distance

in

divisions

between

the

point

on

the

rising or

falling

portion

of

the

waveform

that

is

10% and

the point

that is

90%

of the

total

display

amplitude

(see

Fig. 2-6).

NOTE

The

left

edge

of the

oscilloscope

graticule

is

scribed

with

0, 10,

90,

and

100%

lines

for

convenience

when

measuring

rise

time

or fall

time.

To

use this

feature,

adjust

the

vertical

deflection

factor

and

position

controls

to

fit

the display

between

the

0

and

100%

graticule

lines.

Then

measure

the

horizontal

distance

between

the

points

where

the

waveform

crosses the

10%, and

90%,

graticule

lines.

8. Multiply

the

horizontal

distance

measured

in

step

7

by

the

TIME/DIV

switch

setting.

(Divide

the

answer

by 10

if

sweep

magnification

is

used.)

@

2-9

Operating

Instructions—

7B10

Operators

IOC

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K

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TIME

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:

A

1

i

1

1

1

1

1

y

^

;

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1

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;

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—

IOC

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MEASURE

1

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B

(101

rAL

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MCE F

ROM

FALL

TIME

:

:

]S

1

V

1

1

1

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i

1

1

1

1

1

;\

1

:

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—

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_

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po'

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1985-1

1A

PULSE WIDTH

MEASUREMENTS

Perform

the

following

procedure

to

measure

the pulse

width of

a displayed

waveform:

1.

Install the

time-base

unit in

a mainframe

horizontal

compartment (either

A or

B

horizontal

in

a four-

compartment

mainframe).

2.

Connect the

signal

to be measured

to

the

vertical

unit

input.

3.

Set the

mainframe

horizontal-

and

vertical-mode

switches

to display

the time

base

and

vertical

unit.

(Check

that the

time base

VARIABLE

(CAL IN)

control

is

pushed

in and

the HOLD

OFF

control

is in

the

MIN

position.)

4. Set the

TRIGGERING

switches

and

LEVEL

control

for

a

stable display

(see General

Operating

information

for

selecting

proper triggering).

5.

Set

the

vertical

deflection

factor

and

position

control

for

about

a

5-division

pulse

vertically

centered

on the

graticule.

6.

Set the TIME/DIV

switch

and

POSITION

control

for

1

complete

pulse

displayed

within

the

center

8

graticule

divisions

as shown in Figure

2-7.

7. Measure

the horizontal

distance

in

divisions

between

the

50%

amplitude points

of the

displayed

pulse

(see Fig.

2-7.).

8. Multiply the

horizontal

distance

measured

in

step 7

by

the TIME/DIV

switch

setting.

(Divide

the

answer

by 10 if

sweep magnification

is

used.)

Fig.

2-6.

Measuring

the rise

time and

fall

time

of

a displayed

waveform.

Example:

Assume

that the

horizontal

distance

between

the

50% amplitude

points

is

3 divisions,

and

the

TIME/DIV

switch setting

is

.1

fjs

(see Fig. 2-6).

Using the

formula:

Horizontal

distance

TIME/DIV

Rise

Time

=

(divisions)

x setting

Magnification

Substituting

values:

_

2.5

X

0.1

/is

Rise

Time

=

^

=

0.25 microsecond

PULSE

WIDTH

Fig.

2-7.

Measuring the pulse

width

of

a displayed

waveform.

Example: Assume

that

the horizontal

distance

between

the B amplitude

points is

3 divisions,

and the

TIME/DIV

switch

setting is .1

ms

(see

Fig, 2-7).

Using the formula:

Horizontal

TIME/DIV

Pulse Width

=

distance x setting

Magnification

Substituting values:

Pulse

Width

=

—

=

0.3

millisecond

Operating

Instructions—

7B

10 Operators

DELAYED-SWEEP

MEASUREMENTS

The

time-base unit

may be

used with

a delaying

time-

base unit in

a mainframe

with

two

horizontal

compartments

to make

delayedsweep

measurements.

See

the Tektronix

Products

Catalog

for

compatible

delaying time-base

plug-in

units. If

a compatible

delaying

time-base unit is

available,

refer

to the

instruction

manual for

that unit for

detailed

delayed-sweep

measurement

procedures.

1

Section

3—

7B10

Operators

INSTRUMENT

OPTIONS

No

options were

available

for

this

instrument

at

the

time

of

this

printing.

Information

on

any

subsequent

options

may

be

found

in

the

CHANGE

INFORMATION

section

in the

back

of

this manual.

MANUAL

CHANGE

INFORMATION

At

Tektronix,

we continually

strive to keep

up with latest

electronic

developments

by

adding

circuit

and

component improvements

to

our instruments

as

soon as they

are

developed

and tested.

Sometimes,

due to

printing

and shipping

requirements,

we

can’t get

these

changes

immediately into

printed

manuals. Hence,

your

manual may

contain

new

change

information

on following

pages.

A single

change

may affect several

sections.

Since

the change

information

sheets

are

carried

in the

manual until

all changes

are

permanently

entered,

some

duplication

may occur.

If no

such change

pages appear

following

this page,

your

manual

is correct

as printed.