Tektronix 7B71 Instruction Manual

Tektronix, Inc.

P.O.

Box

500

Beaverton,

Oregon

97005

TEKTRONIX®

DELAYING

TIME

BASE

SN

B2050D0

AND

UP

INSTRUCTION MANUAL

Serial Number

'JtXiiD

~~

^

070

-

1580-00

373

WARRANTY

All

TEKTRONIX

instruments

are

warranted

against

defective

materials

and workmanship

for

one year.

Any

questions

with

respect

to the warranty

should

be taken

up

with

your

TEKTRONIX Field

Engineer

or representative.

All requests

for repair

and replacement

parts

should be

directed

to

the

TEKTRONIX

Field

Office

or

representative

in

your

area.

This will

assure you

the fastest

possible

service.

Please

include

the instrument

Type Number or Part

Number and

Serial

Number’

with all requests

for parte

or

service.

.j,

**

||

''

'''-s.’

Specifications

and price change

privileges

reserved.

Copyright

©

1973 by

Tektronix,

Inc., Beaverton,

Oregon.

Printed

in the

United

States of America.

All

rights

reserved.

Contents of

this

publication

may not

be reproduced

in any

form

without

permission

of

Tektronix,

Inc.

U.S.A. and

Foreign

TEKTRONIX

products

covered

by U.S.

and

foreign

patents

and/or

patents pending.

TEKTRONIX

is

a registered

trademark

of Tektronix,

Inc.

7B71 (SN

B205000and

Up)

TABLE

OF

CONTENTS

Page

SECTION

1

SPECIFICATIONS

Introduction

1-1

Electrical

Characteristics

1-1

Sweep Rate

1-1

Sweep Accuracy

1-1

Sweep Length

1-1

Sweep

Hold-Off Time

1-1

Variable

Time Delay

1-1

Delay

Time Range

1-1

Differential

Delay Time

Measurement Accuracy

1-1

Jitter 1-2

Trigger Sensitivity

1-2

Internal

Trigger Jitter

1-2

External

Trigger Input

1-2

Level Range

1-2

P-P

Auto Sensitivity

1-2

Environmental

Characteristics

Altitude

1-2

Physical

Characteristics

Finish

1-2

Dimensions

1-2

Weight

1-2

SECTION

2

OPERATING

INSTRUCTIONS

General

2-1

Installation

2-1

Front Panel

Controls

2-1

Test

Setup

Chart

2-4

General

Operating

Information

2-4

Sweep

Calibration

Check

2-4

Simplified

Operating

Instructions

2-6

Normal

Sweep

2-6

Magnified

Sweep

2-6

Delayed

Sweep

2-6

Pushbutton

Switch

Logic

2-6

Triggered

Light

2-7

Trigger

Mode

2-7

Trigger

Coupling

2-9

Trigger

Source

2-10

Trigger

Slope

2-10

Trigger

Level

2-10

Horizontal

Sweep Rate

2-12

Sweep Magnifier

2-12

Horizontal

Position

Control

2-13

7B71 (SN

B205000and Up)

TABLE

OF CONTENTS

(cont)

Page

SECTION

2

OPERATING

INSTRUCTIONS

(cont)

Applications

2-13

General

2-13

Measurement

Techniques 2-13

Time Duration

Measurements

2-14

Determining

Frequency

2-15

Risetime

Measurements

2-15

Delay

Sweep

Time

Measurements 2-16

Delayed

Sweep Magnification 2-17

Displaying

Complex Signals

Using Delayed

Sweep

2-18

Pulse Jitter

Measurements 2-18

SECTIONS

CIRCUIT

DESCRIPTION

Introduction

3-1

Block

Diagram

Description

3-1

Detailed

Circuit Description 3-1

Trigger Input 3-1

Input

Source

3-1

Trigger Amplifier

3-2

General

3-2

External Input

Amplifier 3-2

Input

Stage

3-2

Peak Detector 3-3

Slope

Comparator

3-3

Output

Stage

3-4

Trigger

Generator

3-4

Trigger Pulse

Generator

3-4

Sweep

Gate Stage

3-4

Triggered

Hold-Off Stage

3-4

Bright

Line Auto 3-5

Time-Base Generator 3-5

General 3-5

Normal

Trigger Mode

Operation

3-5

Single Sweep Operation 3-8

Alternate

Operation

3-8

Delayed

Sweep Operation

3-8

Delay Pickoff 3-9

Horizontal Preamp 3-9

Readout

Block

3-9

SECTION

4 MAINTENANCE

Preventive Maintenance 4-1

General

4-1

Cleaning

4-1

Visual Inspection

4-1

Transistor

and Integrated

Circuit Checks

4-1

Recalibration

4-1

7B71 (SIM

B205000 and

Up)

TABLE

OF

CONTENTS

(cont)

SECTION

4

MAINTENANCE

(cont)

Page

Troubleshooting

4-2

Troubleshooting

Aids

4-2

Troubleshooting

Equipment

4-2

Troubleshooting

Techniques

4-2

Corrective

Maintenance

4-6

General

4-6

Obtaining

Replacement

Parts

4-6

Soldering

Techniques

4-7

Component

Replacement

4-7

Instrument

Repackaging

4-10

SECTION

5

PERFORMANCE

CHECK/CALIBRATION

Introduction

5--|

Test

Equipment

Required

5-1

Short-Form

Procedure

and

Index

5-2

Performance

Check/Calibration

Procedure

5-4

General

5-4

Preliminary

Control

Settings

5-5

Check/Adjust

Steps (refer

to

Short-Form

Procedure

5-5

for

index

to steps)

SECTION

6

ELECTRICAL

PARTS

LIST

Abbreviations

and

Symbols

Parts

Ordering

Information

Index

of Electrical

Parts

List

SECTION

7

DIAGRAMS

SECTIONS

MECHANICAL

PARTS

LIST

CHANGE

INFORMATION

Abbreviations

and

symbols used

in

this

manual

are

based

on

or

taken

directly

from IEEE

Standard

260

"Standard

Symbols

for

Units",

MIL

STD-1

2B and

other

standards

of the

electronics

industry.

Change

information,

if any,

is

located

at

the rear

of

this

manual.

TRiGGERING

WOOE

COUPlfPiG SOURCE

P-PAOTO

AC

iNT

rmc'D

I

LEVEl/SLOPE

SiNGlE

FINE

POSITION

R^T

MAGNIFIER

READY-

VARJABiE (CAL

IN)

time/div

ORDLYTIME

B

DELAY

MODE

(A INTER

DURING 8}

II

INDEPENDENT

B

STARTS

AFTER DELAY

8

TRIGGERABLE

AFTER DELAY

DELAY

TIME

MULT

DELAYING

TIME

BASE

7B71

Fig.

1-1.

7B71 Delaying

Time

Base.

7B71 (SN

B205000and Up)

7B71 (SN B205000and

Up)

SECTION

1

7B71

SPECIFICATION

Change

information

,

if

any

,

affecting

this section

will

be

found

at the rear of

the

manual.

Introduction

The

7B71 Time Base

Unit is designed

specifically for

use

with Tektronix

7700-Series Oscilloscopes.

However,

it

is

compatible

with all

7000-Series

Oscilloscopes. The

7B71

provides

calibrated

sweeps from

5

seconds/division

to 0.02

microseconds/division

(2 nanoseconds/division

with

X10

MAGNIFIER).

Sweep rates

may

be varied continuously

(uncalibrated)

between

calibrated

steps. Sweep triggering

is

to 200

megahertz

or vertical

amplifier

bandwidth,

which-

ever is less.

The delaying

sweep feature

of

the

7B71, in

delayed

sweep

operation,

gives continuous

sweep

delay

from

0 to 10 times

the setting of

the TIME/DIV

OR DLY

TIME

selector.

The sweep

free-runs

providing

a bright

base-

line

in

the

absence of

adequate

triggering

signal

in P-P

AUTO

and

AUTO

triggering

modes.

The

Performance

Check

procedure

given

in

Section

5 of

this

manual

provides

a

convenient

method

of

checking

per-

formance

of

this

instrument.

The

following

electrical

characteristics

apply

at

an

ambient

temperature

of

0°C to

+50

C,

unless

otherwise

noted.

Warmup

time

for

given

accuracy

is 20

minutes.

TABLE

1-1

Electrical

Characteristics

Characteristic

Performance

Sweep

Rate

Calibrated

Range

5

seconds/division

to

0.02

micro-

seconds/division

in a

1-2-5

se-

quence.

X10

magnifier

extends

sweep

rate

to 2

nanoseconds/

division.

VARIABLE

Range

(uncalibrated)

Continuously

variable

between

cali-

brated

sweep

rates.

Extends

uncali-

brated

sweep

rate

to at least

12.5

seconds/division.

Sweep

Accuracy

Measured

in

7000 series

mainframe

Time

Interval +

15°Cto

+35°C

0°C to

+50°C

Over

Center

Unmag

Mag

Unmag

Mag

8

div

5 s/div

to

0.1

s/div

and

0.2

ys/div

to

0.02

ys/div

3%

3.5%

4%

5%

50

ms/div

to

0.5 ys/div

2%

2.5%

3%

4%

Over

any 2

div

interval

within

center

8 div

5% 7%

a

Characteristic

Performance

Excluded

Divisions

of

Magnified

Sweep

Start

of

Sweep;

12 ns

in

7900

series,

20 ns

in

7704A,

and

50 ns

in

other

7000

series

mainframes.

End

of Sweep;

beyond the

90th

division

Sweep

Length

10 divisions to

13

divisions.

Sweep

Hold-Off

Time

5 s/div

to

5

ys/div

1.5

times

the

TIME/DIVISION

set-

ting

or less.

2

ys/div

to

0.02 ys/div

3.5

microseconds

or

less.

Variable

Time

Delay

Delay

Time

Range

0 to

10

times DELAY

TIME/DIV

setting

from

5 s/div

to

1

ys/div.

Differential

Delay

Time

Measurement

Accuracy

(+15°Cto

+35°

C)

5

s/div

to 1 s/div

±(1.5% of

measurement

+0.3%

of

full

scale).

1-1

Specification-7871

(SN

B205000 and

Up)

TABLE

1-1

(cont)

Characteristic

Performance

0.5 s/div

to

1

/Js/div

±(1 % of

measurement

+0.3%

of full

scale).

Full

scale is

10

times the

DELAY

TIME/DIV

setting. Accu-

racy

applies

over the

center

8

major

DTM

divisions.

Jitter

1

part

or

less

in

50,000

of

10 times

the TIME/DIV

setting.

Trigger

Sensitivity

Triggering

Frequency

Range*

Minimum

Trig-

gering

Signal

Required

Coupling

INT

EXT

AC

30 Hz

to

20 MHz

0.3

div

75 mV

20

MHz

to

200 MHz

1.5

div

375

mV

AC LF

REJ2

30

kHz

to

20 MHz

0.3 div 75

mV

20

MHz

to

200

MHz

1

.5 div

375

mV

AC HF

REJ

30 Hz

to

50

kHz

0.3 div

75 mV

DC

DC

to

20 MHz

0.3

div

75

mV

i

20 MHz

to

200 MHz

1

.5

div

375 mV

Single

Sweep

Triggering

requirements

same

as

normal

sweep.

When

triggered,

sweep

generator

produces

one

sweep only.

Internal

Trigger

Jitter

1 nanosecond

hertz.

or less

at 1 50 mega-

External

Trigger Input

Maximum

Input

Voltage

500

volts

(DC

+

Peak

AC). 500

volts (P-P

AC) at 1

kilohertz

or

less.

On

Internal Triggering

Only;

the specified

upper

—3

dB

frequency

of

the

Vertical

System replaces

upper limit

frequencies

in

the

above table

when the

number in

the table is greater

than

the

—3

dB

frequency

of

the Vertical

System.

2

Will not trigger

on sine

waves of

3 divisions or

less internal or

1.5

volts

external below

120 Hz.

TABLE

1-1

(cont)

Characteristic

Performance

Input R and C 1

megohm within

2%,

20

picofarads

within

2

picofarads.

Level Range

(Excluding

P-P AUTO)

EXT

EXT+ 10

At

least

+1

.5 volts to—1.5

volts.

At least

+15

volts to

—15

volts.

P-P

AUTO

operation

Sensitivity

0.5 div

Internal,

125

millivolts

External 200

Hz

to

20

MHz. Upper

frequency

and amplitude

limits

same as

NORMAL

Trigger

Sensi-

tivity.

Low

Frequency

Response

Must

Trigger

on 50

hertz, 2 division

signal.

TABLE

1-2

Environmental Characteristics

This

instrument will meet the electrical

characteristics given

in Table

T1 over the

following

environmental limits.

Characteristic Performance

Altitude

Non-operating To

50,000 feet and

-55"

C.

TABLE

1-3

Physical

Characteristics

Finish

Front

panel is anodized

aluminum.

Dimensions

Fits single

plug-in

compartment of

7000-series

oscilloscope.

Weight

Approximately

2.88

pounds.

1-2

7B71

(SN B205000and

Up)

SECTION 2

OPERATING

INSTRUCTIONS

Change information,

if any, affecting this section will

be found at the rear

of the manual.

General

The 7B71 delaying sweep plug-in unit operates with

a

Tektronix 7000-series indicator oscilloscope and a 7A-series

vertical plug-in unit

to

form

a complete oscilloscope

system. To

use

the 7B71

effectively,

its operation

and

capabilities should be known. This section

describes the

operation of the front-panel

controls, gives first-time

and

general operating

information

and lists some basic applica-

tions

for

this instrument.

Installation

The

7B71 is

designed

to operate in the horizontal plug-in

compartments

of

Tektronix 7000-series oscilloscopes.

The

7B71

can also

be

installed

in a vertical plug-in compartment

to provide a sweep

that

runs vertically

on

the

CRT. How-

ever,

when used

in

this manner, there

is no retrace blanking

or

internal

triggering provision

and

the unit

may not meet

the specifications given in Section

1.

The

instructions

in

this manual are written for

use of the

7B71

in

a horizontal

plug-in compartment of

the oscilloscope.

When

the 7B71 is

used with

an oscilloscope

which has

two

horizontal

plug-in

compartments,

install this unit

in the

A (DELAYING TIME

BASE)

compartment.

Then,

if

a

delayed-sweep unit is

installed in

the B (right)

compart-

ment,

delayed-sweep

operation is available.

The

7B71 will

operate properly in the

B

compartment for all horizontal

modes of operation

except

delaying sweep.

To

install the

7B71 into a plug-in compartment,

push it

in until it fits firmly into

the indicator plug-in compart-

ment.

To

remove, pull the

release latch (see Fig. 2-1)

to

disengage the unit from

the indicator and pull it out of the

plug-in compartment.

Even though the horizontal

gain

of

the indicator

oscilloscope

is

standardized

to minimize

adjustment when

inserting plug-in units, the

sweep calibra-

tion of the

7B71 should be checked when

it is inserted into

the indicator

to

verify

measurement accuracy.

The

pro-

cedure for

checking the unit

is given under Sweep Calibra-

tion

Check

in this section.

FRONT-PANEL CONTROLS

General

All controls

required

for the operation of

the 7B71 are

located on the front panel of

the unit

(see Fig. 2-2).

To

Release

Latch

Fig.

2-1.

Location of

release

latch.

make

full

use of the

capabilities of

this instrument,

the

operator

should be familiar

with the

function

and use of

each of these

controls.

A

brief

description of

the front-

panel controls

and connector

is given

here. More detailed

information

is given

under General

Operating

Information.

Triggering

Controls

LEVEL/SLOPE

Selects

the amplitude

point

and

slope of

trigger

signal on

which the

sweep

is triggered. When

the indica-

tor line

on the

outer ring

is to the

left

of

center, the

sweep is triggered

on

the

positive-going

slope of the

trigger

signal,

as shown by the

positive-going

waveform.

To the

right

of center,

the sweep

is trig-

gered

on the

negative-going slope of

the

trigger

signal as shown

by the

negative-going

waveform.

TRIC'D

Light indicates

that the sweep is

triggered

and will produce a display

with

correct setting of the POSI-

TION control

and

the

controls on

the

associated vertical unit

and

indi-

cator

oscilloscope.

[A]

2-1

MODE COUPUNG

SOURCE

P PAUTO

AC INT

LEVEL/SLOPE

INOEPENDEN1

Operating

lnstructions-7B71

(SN

B205000

and

Up)

TRIC'D

0

TRIGGERING

TRIGGER

CONTROLS

AUTO

ACIFREJ tIN£

NORM

ACHFREJ EXT

SINGLE

SWP -I

DC EXT

^10

FINE

POSITION

. ARIAIU

f

CAL

IN

ime/divor

dly time

B DELAY MODE

lA INTER DURING I-

SWEEP

CONTROLS

B STARTS

1,.

AFTER

DEUY

/50

B TRIGGERABLE

AFTER

DEUY

DELAY

CONTROLS

DEUY

T ME MULT

TRIGGER

CONTROL

Fig. 2-2.

Front-Panel

controls

and

connectors.

MODE

Series

of

push-button

switches

to

select

the

trigger

mode.

Selected

mode

is

indicated

by

lighted

button.

P-P

AUTO:

Sweep

automatically

triggered

at point

selected

by the

LEVEL/SLOPE

control

when

the

trigger

signal

repetition

rate

is

above

about

200

hertz

and

within

the

frequency

range

selected

by the

COUPLING

switch.

Triggered

sweep

can be

obtained

throughout

the range

of

the

LEVEL/SLOPE

control.

When

the

trigger

repetition

rate

is

below

the

lower

frequency

limit

(or

above

upper limit for

AC

HF REJ)

or when

the trigger

signal

is

inadequate,

the

sweep

free

runs

at the

sweep

rate

selected

by

the TIME/DIV

switch

to

produce a reference

trace.

2-2

lA]

Operating

Instructions—

7B71

(SN

B205000

and Up)

AUTO:

Sweep

initiated

by

the

applied

trigger

signal

at

point

selected

by

the

LEVEL/SLOPE

control

when

the

trigger

signal

repetition

rate

is

above

about

30

hertz

and

within

the

frequency

range

selected

by

the

COU-

PLING

switch.

Triggered

sweep

can

be

obtained

only

over

the

amplitude

range

of

the

applied

trigger

signal.

When

the

LEVEL/

SLOPE

control

is

outside

the

amplitude

range,

the

trigger

repetition

rate

is

below

the

COUPLING

lower

frequency

limit

(or

above

upper

limit

for

AC HF

REJ)

or

the

trigger

signal

is

inadequate,

the

sweep

free

runs

at the

sweep

rate

selected

by

the

TIM

E/D

IV

switch

to

produce

a

reference

trace.

NORM:

Sweep

initiated

by

the

applied

trigger

signal

at

any

point

selected

by the

LEVEL/

SLOPE

control

over

the fre-

quency

range

selected

by the

COUPLING

switch.

Triggered

sweep

can

be

obtained

only

over

the

amplitude

range

of

the

applied

trigger

signal.

When

the

LEVEL/SLOPE

control

is

out-

side

the

amplitude

range,

the

trigger

repetition

rate

is

outside

the

frequency

range

selected

by

the

COUPLING

switch

or

the

trigger

signal

is

inadequate,

there

is no

trace.

RESET-READY:

Push-button

to

reset

the

Sweep Generator for

the

next

sweep in the

single-

sweep

mode. The

RESET-

READY

button

remains

lighted

to indicate

that the

unit is ready

to

be triggered. After

the unit is

triggered

and

a sweep is

com-

pleted,

the

RESET-READY

light

goes

out until

the

button is

pressed

again.

Series

of

push-button

switches

to

select

the

trigger

coupling.

Selected

coupling

is

indicated

by

lighted

button.

AC:

Rejects

DC

and

attenuates

AC

signals

below

about

30

hertz.

Accepts

signals

between

30 hertz

and

200

megahertz.

AC

LF

REJ:

Rejects

DC

and

attenuates

signals

below

about

30

kilohertz.

Accepts

signals

between

30

kilohertz

and

200

megahertz.

AC HF

REJ:

Accepts

signals

be-

tween

about

30 hertz

and

50

kilohertz.

Rejects

DC

and

atten-

uates

signals

outside

this

fre-

quency

range.

DC:

Accepts

all

trigger

signals from

DC

to

200 megahertz.

SINGLE

SWP:

Sweep initiated

by

SOURCE

the

applied

trigger signal

at any

point

selected

by the LEVEL/

SLOPE

control over

the

fre-

quency range

selected

by the

COUPLING

switch.

Triggered

sweep

can be obtained

only over

the

amplitude

range of

applied

trigger

signal.

After

the first

sweep

is

displayed,

further

sweeps

cannot

be presented

until

the

RESET-READY

push-

button

is pressed.

When the

LEVEL/SLOPE

control

is

out-

side

the

amplitude

range,

the

trigger

repetition

rate

is

outside

the

frequency

range

selected

by

the

COUPLING

switch, the trig-

ger

signal

is inadequate

or when

the

RESET-READY

light

is off,

there

is no trace.

Series

of

push-button

switches

to

select

the

trigger

source.

Selected

source

is indicated

by

lighted

button.

I NT:

Trigger

signal

obtained

inter-

nally

from

a

vertical

unit.

LINE:

Trigger

signal

obtained

internally

from

a sample of

the

line

voltage

applied

to this

instrument.

EXT:

Trigger

signal

obtained

from

an

external

signal

applied

to the

EXT

TRIG IN

connector.

EXT

^

10: Trigger

signal

obtained

from

an external

signal

applied

to the EXT

TRIG IN

connector

as in the

EXT

position.

In this

2-3

Operating

lnstructions-7B71

(SIM

B205000

and

Up)

EXT

TRIG IN

Sweep

Controls

POSITION

FINE

TIME/DIV

OR

DLY

TIME

VARIABLE

MAGNIFIER

position

the

external

signal

is

SWP

CAL

attenuated

10

times

before

it is

applied

to the

trigger circuit.

Screwdriver

adjustment

to

set

amplitude

of

the

output

sawtooth.

Input

connector

for

external

trigger

signal.

Controls

horizontal

position

of

display.

Provides

more

precise

control

of

horizontal

positions.

Selects

the

basic sweep

rate of

the

output

sawtooth

and

selects

basic

delay time

(to be

multiplied

by the

DELAY

TIME

MULT

dial setting).

The

VARIABLE

control

must be in

calibrated

position

and

MAGNI-

FIED

switch

set

to XI for

indicated

sweep

rate.

Two-position

switch

actuated

by

the VARIABLE

knob to select

cali-

brated

or uncalibrated

sweep rates.

At the in

position, the

VARIABLE

control

is inoperative

and the

sweep

rate

is calibrated.

When

pressed

and

released,

the knob

moves

out to

activate

the VARIABLE

control

for

uncalibrated

sweep

rates.

The

sweep

rate in

each TIME/DIV

switch

position

can be reduced

to

at least

the sweep

rate of

the next

adjacent

position,

to provide

con-

tinuously

variable sweep

rates from

2

nanoseconds/division

(X10-

MAGNIFIER

on) to about

12.5

seconds/division,

with

MAGNI-

FIER

at XI.

Series

of

push-button

switches

to

select

the

delay

logic

to

the

com-

panion

delayed-sweep

unit

(B).

Selected

delay

mode

is

indicated

by

a

lighted

button.

INDEPENDENT:

The

7B71

and

the

companion

delayed-sweep

unit

(B)

operate

independently

as

normal

time-base

units.

B STARTS AFTER

DELAY;

The

companion

delayed-sweep

unit

(B)

produces

a

sweep

immediate-

ly following

the delay

time

selected

by

the

TIME/DIV

OR

DLY

TIME

switch

and the

DELAY TIME

MULT

dial.

B

TRIGGERABLE

AFTER

DELAY:

The

companion

delayed-

sweep

unit

(B) produces

a

sweep

after

the

first

trigger

pulse is

received

following

the

delay

time

selected

by

the

TIME/DIV

OR

DLY

TIME

switch

and

the

DELAY

TIME MULT

DIAL.

LT Provides

variable

delay for

the

delay

pulse

to the

companion

delayed-sweep

unit

(B)

from

0 to

10 times

the

basic delay

time

selec-

ted

by

the

TIME/DIV

OR

DELAY

TIME

switch.

TEST

SETUP

CHART

Delay

Controls

B

DELAY

MODE

(A

INTEN

DURING

B)

DELAY

TIME

MU

Push-button

switches

to select

the

horizontal

magnification. The

Selected

magnification

is indicated

by

a lighted

button.

XI:

Magnified

sweep

at the basic

sweep rate

indicated

by TIME/

DIV switch.

General

Fig, 2-3

shows

the

front

panel of

the

7B71.

This chart

can

be

reproduced

and

used

as

a test-setup

record

for

special

measurements,

applications

or

procedures,

or

it may

be

used

as a

training

aid for

familiarization

with

this

instrument.

X10:

Magnified

sweep

at

a

sweep

rate

10 times

faster

than the

basic

sweep rate

indicated

by the

TIME/DIV

switch.

The

portion

of

the normal

sweep

within the

center division

of

the graticule

is

the

portion

shown in

magnified

form.

GENERAL

OPERATING

INFORMATION

Sweep

Calibration

Check

Whenever the

7B71 is inserted

into

a plug-in

compart-

ment other

than

the

one in

which

it was

calibrated,

the

sweep

calibration

should

be

checked

and

readjusted if

necessary.

Allow

five

minutes

warmup

before

performing

this

procedure.

2-4

Operating

lnstructions-7B71

(SN

B205000 and

Up)

7B71

TEST

SET-UP

CHART

NOTES:

Fig.

2-3.

7B71 Test

Setup Chart.

Operating

lnstructions-7B71

(SN

B205000 and Up)

NOTE

For

accurate

sweep

timing,

apply

a signal

of

known

frequency

or time

period

(time-mark

signal,

calibrator

square

wave,

60

hertz line

etc.)

to the

associated

vertical

amplifier

unit

and adjust

the

TIME/DIV

OR

DLY

TIME

switch

and

the

SWP

CAL

control

to

calibrate

the

signal

to the

oscilloscope

graticule.

Be

sure

that

the sweep

timing

signal is

accurate

within

0.

5.. The

following

sweep

calibration

procedure

uses

a Tektronix

Time-Mark

Generator.

1.

Connect

a 1 millisecond

time-mark

signal

from

the

Time-Mark

Generator

with

a 50-ohm BNC

coaxial

cable

and

50-ohm BNC

termination

to the

Input

of the

associated

vertical

unit.

2.

Set the

TIME/DIV

switch

to 1 ms

and

press the

top

TRIGGERING

and

B

DELAY

MODE

pushbuttons.

3. Set

the

Vertical

unit

to display

at least

two

divisions

of the

signal vertically.

4. Check

the CRT

display

for

one

complete

cycle

per

division.

5.

If

necessary,

adjust

the

SWP

CAL

adjustment

for

one

complete

cycle per

division.

Simplified

Operating

Instructions

The

following

information

is

provided

to

aid in

quickly

obtaining

the

correct

settings

for

the

7B71

to present

a

display.

The

operator

should

be

familiar

with

the

complete

function

and

operation

of

the

unit

as

described

in

this

section

before

using this

procedure.

Normal

Sweep.

The following

procedure

will

provide

a

stable display

for

most

normal-sweep

applications.

1. Select

the

TRIGGERING

MODE,

COUPLING

and

SOURCE

which fit

the

requirements

of

the signal

to be

displayed.

2. Turn the LEVEL/SLOPE control

to the desired slope.

3.

If

the green TRIG'D

light

is not on,

adjust the

LEVEL/SLOPE

control

throughout

the range of

the selec-

ted

slope until the TRIG'D

light

comes

on.

If

the light

does

not

come on at any setting

of

the LEVEL/SLOPE

control,

the trigger

signal is

inadequate

or the

COUPLING

and

SOURCE

switches

are set

incorrectly.

4.

Set the TIME/DIV

switch

and POSITION

control for

a display

which remains

on

the display

area horizontally

(VARIABLE

control should

be in

CAL

position for cali-

brated

sweep rates)

.

5.

If

the display

does

not

start

at

the

correct

point

on

the waveform,

readjust

the

LEVEL/SLOPE

control for

the

desired

triggering.

Magnified

Sweep.

A

magnified-sweep

display

can be

obtained

as follows after

a normal

-sweep display

is

obtained

as given

in steps

1-5

above.

1.

Adjust

the

POSITION

control

to

move the

area

to be

magnified

within the

center

division

of

the

CRT.

2.

If

necessary,

change

the

TIME/DIV

switch

setting

so

the

complete

area

to be

magnified

is

within the

center

divi-

sion.

3. Press the

X10-MAGNIFIER

push-button.

4. Use

the fine

range

of

the

POSITION

control

to

establish

precise

positioning

of

the

magnified

display.

Delayed

Sweep.

The

following

procedure

can be

used

to

obtain

a delayed-sweep

display

when the

7B71

is

used in

an

oscilloscope

that

has

dual

time

base

capabilities

and

when

used

with

a

companion

delayed-sweep

unit

(B).

Obtain

a

display

as given

in

steps

1-5

under

Normal

Sweep.

Then

proceed

as follows:

1.

Press

the B

STARTS

AFTER

DELAY

push-button.

2. Set the

indicator

oscilloscope

horizontal

mode

to dis-

play the

A time

base (7B71).

3. Set

the

time/division

switch

of

the

companion

delayed-sweep

unit

(B) so

the

intensified

zone

on the

dis-

play

is the

desired

length

(intensified

zone

will be

displayed

in

delayed

form).

If

the

intensified

zone

is

not

visible,

adjust

the

indicator

intensity

controls.

4.

Adjust

the

DELAY

TIME

MULT

dial

to position

the

intensified

zone

to

the

portion

of

the

display

to be

delayed.

5.

Set

the

indicator

oscilloscope

horizontal

mode

to dis-

play

the

B time

base

(delayed

sweep

unit).

6.

If

a delayed

sweep

with less

jitter

is desired,

press

the

7B71

B

TRIGGERABLE

AFTER

DELAY

push-button.

The triggering

controls

of the

companion

delayed-sweep

unit

(B) must

be set

to obtain

a

stable

display.

See

the

instruction

manual for

that

unit for

further

information.

Pushbutton

Switch

Logic

The

TRIGGERING

MODE,

COUPLING

and

SOURCE

switches

and

the

B

DELAY

MODE

switch

are

arranged

in

a

2-6

m

Operating lnstructions-7B71

(SN

B205000

and

Up)

sequence

which

places

the

most

often-used

position

at the

top of

each

series

of

pushbuttons.

With

this

arrangement,

a

stable

display

can

usually

be

obtained

by pressing

the top

push-buttons;

P-P

AUTO,

AC,

INT

and

INDEPENDENT.

When

an adequate

trigger

signal

is

applied,

the

unit

is trig-

gered

as indicated

by the

illuminated

TRIC'D

light

at

any

setting

of

the

LEVEL/SLOPE

control.

If

the

TRIC'D

light

is not

on,

either

the

trigger

signal

applied

to this

unit from

the

vertical

unit

is

inadequate

or it

is below

the lower

fre-

quency

limit of

the

AC

COUPLINC

switch

position.

If

the

desired

display

is not

obtained

with

the

pushbuttons

pushed

in,

other

selections

must

be

made.

Refer

to the

following

discussions

or the

instruction

manuals

for

the

associated

indicator

oscilloscope

and

vertical

unit for

more

information.

Triggered

Light

The

TRIC'D light

provides

a

convenient

indication

of

the

condition

of the

triggering

circuits.

If

the

TRICCERINC

controls

are correctly

set

and

an adequate

trigger

signal

is

applied, the

TRIC'D

light

is on.

Under

certain

conditions,

the

TRIC'D

light

may

be off,

indicating

that

the sweep

is

not

triggered.

The

cause

might

be

a

misadjusted

LEVEL/

SLOPE

control,

incorrectly

set

COUPLINC

or

SOURCE

switches,

low trigger

signal

amplitude,

or a trigger

signal

repetition

rate

outside

the

acceptable

frequency

range.

This

feature

can

be used

as a

general

indication

of

correct

trig-

gering.

It is

particularly

useful

when

setting

up the

trigger

circuits

when

a trigger

signal

is available

without

a display

on

the

CRT.

It also

indicates

that

this

unit is

correctly

triggered

when

operating

as a

delaying-sweep

unit

(A).

Trigger

Mode

The

pushbuttons

located

under

the

MODE

title

(see Fig.

2-4)

select the

mode

in which

the

sweep

is

triggered.

The

selected

mode

is indicated

by

a lighted

pushbutton.

P-P

AUTO.

When

the P-P

AUTO

pushbutton

is

pressed,

a triggered

display is

provided

at

any

setting

of the

LEVEL/

SLOPE

control

whenever

an

adequate

trigger

signal

is

applied.

The

range of

the

LEVEL/SLOPE

control

in this

mode

is

between

about

10%

and

90% of

the

peak-to-peak

amplitude

of the

applied

trigger

signal.

The

LEVEL/SLOPE

control

can

be set

so the

displayed

waveform

starts

at

any

point

within

this range

on either

slope.

In

the P-P

AUTO

mode,

the

trigger

circuit

automatically

compensates

for

changes

in trigger

signal

amplitude

for

signals

above

the

minimum

amplitude

requirement.

Therefore,

if

the

LEVEL/SLOPE

control

is

set

so the

displayed

waveform

starts

at a certain

percentage-point

on

the leading

edge of

a

low-amplitude

signal,

it

triggers

at the

same

percentage-

point

on the

leading

edge

of

a

high-amplitude

signal

if

the

LEVEL/SLOPE

control

is

not

changed.

This

operation

is

illustrated

in

Fig.

2-5.

When

the trigger

repetition

rate

is below

about

200

hertz

(or

outside

the

frequency

range

selected

by the

COUPLING

switch),

or

when the

trigger

signal

is

inadequate,

the

sweep

free

runs

at the

sweep

rate

indicated

by the

TIME/DIV

switch

to produce

a reference

trace

(TRIG'D

light

off).

When

an adequate

trigger

signal

is

again

applied,

the free-

running

condition

ends

and

a triggered

display

is

presented.

MODE

COUPLING SOURCE

pushbuttons

pushbuttons

pushbuttons

TRIG'D

H

LEVEL/SLOPE

FINE

POSITION

B

DELAY

MODE

(A INTEN

DURING

B)

H

independent

\

TRIGGERING

/

MODE COUPLING

SOURCE

PPAUTO

AC

INT

SINGLE

SWP

‘

READY-

OC EXIT

10

B

B

MAGNIFIER

XI fi

X10

CAL IN

TIME/DIV

OR

DLY

TIME

ms'

Fig.

2-4.

Exploded

view of front

panel showing

push-buttons

associated

with the

MODE,

COUPLING

and

SOURCE switches.

The P-P

AUTO

trigger

mode

is

particularly

useful

when

observing

a series

of

waveforms,

since

it is

not

necessary

to

reset

the

LEVEL/SLOPE

control

for

each

observation.

Also,

because of

the

ease

of

obtaining

a

triggered

display

in

this

mode,

the P-P

AUTO

trigger

mode

can be

used for

most

applications

and the

remaining

modes

used

only

for

special

applications

or

when

stable

triggering

is not

obtain-

able

in this

mode.

AUTO.

When

the

AUTO

push-button

is

illuminated,

a

triggered

display

is

presented

with

the

correct

setting

of

the

LEVEL/SLOPE

control

(see

Trigger

Level

discussion)

whenever

an

adequate

trigger

signal

is

applied.

The range

of

the

LEVEL/SLOPE

control

in this

mode

is ±8

vertical

divi-

sions.

The

TRIG'D

light

indicates

when

the

display

is

triggered.

When

the trigger

repetition

rate

is

below

about

30 hertz

(or

outside the

frequency

range

selected

by the

COUPLING

switch)

or when

the

trigger

signal

is

inadequate,

the sweep

free

runs at

the sweep

rate

indicated

by

the

TIME/DIV

switch

to

produce

a

reference

trace

(TRIG'D

light off).

When

an

adequate

trigger

signal

is again

applied,

the free-

running

condition

ends

and

a triggered

display

is

presented.

2-7

Operating

lnstructions-7B71

(SN B205000

and

Up)

Fig.

2-5.

LEVEL/SLOPE control

operation for

(P-P) AUTO mode

triggering.

(A) LEVEL/SLOPE control

so displayed

waveform starts

at

about

25%

point

of a two-division

waveform.

(B) displayed

waveform still triggered

at about

25%

of leading

edge, when signal

amplitude is

increased,

to produce

a

six-division

display

(LEVEL/SLOPE

control at same

setting for both waveforms).

When

the LEVEL/SLOPE control

is at a setting outside the

amplitude

range of the trigger signal,

the sweep also free

runs at the

sweep

rate

indicated

by the TIME/DIV

switch.

This

type

of free-running

display can be useful when

it

is

desired

to

measure only

the maximum peak-to-peak

ampli-

tude of a

signal without

observing the waveshape

(such as in

bandwidth measurements).

NORM. When the NORM

push-button is pressed,

a

triggered

display is

presented

with the correct

setting

of

the

LEVEL/SLOPE control whenever an

adequate trigger signal

is

applied. The range

of the

LEVEL/SLOPE control

in

this

mode is

±8 vertical divisions.

The TRIC'D light

indicates

when

the display is triggered.

The NORM

trigger mode

must be used to produce trig-

gered displays with

trigger repetition

rates below about 30

hertz.

When the LEVEL/SLOPE control

is at a setting out-

side the amplitude

range of the trigger

signal, when the

trigger

repetition

rate is

outside

the

frequency

range selec-

ted

by

the COUPLING switch or when the trigger signal is

inadequate, there

is

no trace

(TRIC'D light

off).

SINGLE

SWP.

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.

A

stable display

can

often

be obtain-

ed under

these circumstances

by using the single-sweep

feature of this unit. The SINGLE SWP

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

pushbutton. When ready

to view

the single-sweep display,

press the RESET-READY

push-

button.

A single trace

is presented each time the RESET-

READY

pushbutton is pressed

(as long as the repetitive

signal remains

connected to the system

and

TRIGGERING

controls are correctly set)

and further sweeps cannot

be

presented until the RESET-READY

pushbutton is pressed

again. If the displayed signal

is a complex waveform

com-

posed

of pulses of varying amplitude, successive single-

sweep displays may

not start

at

the same point of the wave-

form.

To avoid

confusion due

to the CRT persistence, allow

the

display to decay

before

pressing the

RESET-READY

pushbutton 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

using

a

viewing

hood as

recommended in

the indicator

instruction

manual.

Non-repetitive, random signals can be

displayed in

the

single-sweep mode by

first

obtaining

the best possible dis-

play in the

NORM MODE with

a signal

which

is about

the

same amplitude

and

frequency

as the random

signal. Then

without changing the other TRIGGERING controls, press

the SINGLE

SWP pushbutton. When ready for

the

random

signal, press

the RESET-READY pushbutton. The RESET-

READY

pushbutton remains

lighted to indicate that

the

unit

has been reset and

is ready

to produce a sweep. The

light

goes

out

after

the

random signal

triggers the

unit. To

prepare the

unit for

another

single-sweep

display, press

the

RESET-READY

pushbutton

again.

When

using

the single-sweep

mode

to photograph

wave-

forms,

the graticule

must

be

photographed

separately in

the

normal

manner

to prevent

over-exposing

the film.

Be sure

2-8

[A]

Operating Instructions—

7B71

(SN

B205000

and Up)

the camera

system is well protected

against stray light, or

operate the system in a darkened

room.

For

repetitive

waveforms, press the RESET-READY

pushbutton

only

once for

each

waveform

unless the signal

is

completely

symmetrical. Otherwise, multiple waveforms

may

appear

on

the

film. For random signals, the camera lens can be left

open until the random signal triggers the unit (RESET-

READY pushbutton lighted). Further information

on

photographic techniques

is given in the camera instruction

manual.

Trigger Coupling

The

pushbuttons located below the COUPLING title

(see

Fig. 2-4) select the method in which the trigger signal

is

connected to the

trigger

circuits. The selected coupling

is

indicated by a

lighted pushbutton. Each

position permits

selection or rejection

of

the frequency

components

of

the

trigger signal which trigger the

sweep. Fig. 2-6 graphically

illustrates

the band

of frequencies

covered

by each position

of

the COUPLING switch.

AC.

In the AC position of

the COUPLING

switch, the

DC component of the trigger signal

is blocked. Signals

with

low-frequency

components below

about 30 hertz are atten-

uated.

In general,

AC

COUPLING

can be used for

most

applications. However, if

the signal

contains unwanted

fre-

quency

components

or

if

the sweep

is to be triggered

at a

low

repetition

rate or

DC level,

one of the remaining

COUPLING switch

positions

will provide

a better display.

The triggering

point in the

AC position depends

upon

the average voltage

level of

the

trigger signal. If

the trigger

signal occurs

randomly,

the average

voltage

level will vary,

causing

the triggering

point

to vary also.

This shift of

the

triggering

point

may be enough

so it is

impossible

to main-

tain

a

stable

display.

In such

cases,

use DC

coupling.

AC LF REJ.

In the

AC LF

REJ

position, DC

is rejected

and

low-frequency

trigger signals

below

about

30 kilohertz

are

attenuated. 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

(with

dual-trace

vertical

or

slaved

triggering

operation for

dual-vertical

unit

operation).

AC

HF REJ.

The

AC HF REJ

position

passes all

low-

frequency

signals between

about

30 hertz

and 50 kilohertz.

DC is

rejected and

signals outside

the

above range are

atten-

uated.

When triggering from

complex

waveforms, this

posi-

tion is

useful for

providing

stable

display of the

low-

frequency

components.

200

MHz

kHz

10

MHz

100 MHz

CAL IN

TiME/DIV

OR DLY

TIME

SINGLE

SWP

RESET

B

READY-

MAGNIFIER

^

XI S

xio

TRIGGERING

MODE COUPUNfi SOURCE

P-PAUTO

AC

AUTO

10 kHz

100

DC

10

Hz 100

Hz

Fig.

2-6.

Frequency

range of

each

COUPLING

switch

position.

[A]

2-9

Operating

lnstructions-7B71

(SN

B205000

and

Up)

DC.

DC

COUPLING

can be

used

to provide

stable trig-

gering

with

low-frequency

signals

which

would

be atten-

uated

in the

other

modes,

or

with

low-repetition

rate

signals.

It

can also

be used

to trigger

the

sweep when

the

trigger signal

reaches

a DC

level

selected

by the

setting

of

the

LEVEL/SLOPE

control.

When

using internal

triggering,

the

setting of

the

vertical

unit

position

controls

affects

the

DC

triggering

point.

Trigger

Source

The

pushbuttons

located

below the

SOURCE title

(see

Fig.

2-4)

select

the

source of

the

trigger

signal

which is

connected

to the trigger

circuits.

The

selected

source

is indi-

cated

by a lighted

pushbutton.

INT.

In the INT

position

of

the

SOURCE

switch, the

trigger

signal is

derived from

the

associated

vertical

unit.

Further

selection of

the

internal

trigger

signal

may

be pro-

vided

by the associated

vertical

unit

or indicator

oscillo-

scope;

see the

instruction

manuals for

these

instruments for

information. For

most

applications,

the

INT-SOURCE

posi-

tion

can

be used.

However,

some

applications

require

special

triggering

which

cannot be

obtained

in the INT-

SOURCE

position.

In

such

cases

LINE- or

EXT-SOURCE

must

be

used.

LINE.

The LINE

position

of

the

SOURCE

switch

con-

nects

a sample of the

power-line

voltage,

to which

the indi-

cator

oscilloscope

is connected,

to the trigger

circuit.

Line

triggering

is useful

when

the

input

signal is

time-related

(multiple

or sub-multiple)

to the line

frequency.

It

is also

useful

for

providing

a stable

display

of

a line-frequency

component

in a complex

waveform.

EXT.

An external

signal

connected

to the

EXT

TRIG

IN connector

can

be used

to trigger

the

sweep in

the EXT-

SOURCE position.

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

too low

in amplitude

for

correct

triggering

or contains

signal

components

on which

it is not

desired

to trigger.

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 under

test

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.

EXT

^

10.

Operation

in the EXT

10

position

is the

same

as described for EXT

except

that the

external

signal is

attenuated

10 times.

Attenuation of

high-amplitude

exter-

nal

trigger

signals is

desirable

to

broaden

the

range of

the

LEVEL/SLOPE

control.

Trigger

Slope

The

LEVEL/SLOPE

control

determines

whether

the

trigger

circuit

responds

on

the

positive-going

or negative-

going

portion of

the trigger

signal.

When

the

indicator

line

on

the

outer ring

of the

LEVEL/SLOPE

control is

to the

left

of

center,

the

display

starts

on the

positive-going

por-

tion

of

the

waveform

(notice

positive-going

waveform

to

left

of

control.

To the right

of

center,

the display

starts

on

the

negative-going

portion

of

the

waveform

(notice

negative-going

waveform).

The

effect

of

the

LEVEL/

SLOPE

control

on

the

displayed

waveform

is

shown

in Fig.

2-7.

When

several

cycles of

a signal

appear

in

the

display,

the

selection

of

the

trigger

slope

is

often

unimportant.

However, if

only

a certain

portion

of

a cycle

is

to be

dis-

played,

correct

setting of

the

LEVEL/SLOPE

control is

important

to

provide

a display

which

starts

on the

desired

slope

of the

input

signal.

Trigger

Level

The

LEVEL/SLOPE

control

determines

the voltage level

on the trigger

signal

at which

the

display

is triggered,

as well

as selecting

the

trigger

slope.

The

center

knob of

the

LEVEL/SLOPE

control

provides

about

a

3:1

reduction in

relation

to

the outer

indicator

ring,

to allow

precise

level

selection.

This

control

can also

be

turned

throughout

the

complete

360°

rotation

to allow

continuous

triggering

over

the

selected

slope.

This is

particularly

useful

in the P-P

AUTO MODE.

When

the

LEVEL/SLOPE

control

is set

to

the

'

0

"

on

either the

positive-going

or

negative-going

wave-

form,

the sweep

is

triggered

near

the zero-volt

level of

the

trigger

signal.

As

the

LEVEL/SLOPE

control

is rotated

away from

the

“0”,

the

displayed

waveform

starts

at a

point

corresponding

to the

position of

the

indicator

line

on

the

associated

slope

waveform

(within

amplitude

range of

trigger

signal

except

in

P-P

AUTO

MODE

which

provides

triggered

display

throughout

entire

slope).

For

example if

the

LEVEL/SLOPE

control

is

turned

clockwise

from

the

“O"

on the

positive-going

slope,

the

displayed

waveform

starts

at

a more

positive

level. Fig.

2-7

illustrates

the

opera-

tion of

the

LEVEL/SLOPE

control

at different

levels

and

slopes

of

a displayed

waveform.

Before

setting

the

triggering

level,

select the

TRIG-

GERING

SLOPE,

MODE,

COUPLING

and SOURCE.

Then

adjust

the

LEVEL/SLOPE

control

so the

displayed

wave-

form

starts

at the desired

point.

The triggering

slope

can be

changed

at any

time

by rotating

the

LEVEL/SLOPE

con-

trol

to

the

corresponding

point

on

the other

slope

waveform.

2-10

Operating

lnstructions-7B71

(SN B205000 and

Up)

CRT displays

obtained with

LEVEL/SLOPE

control in

negative-slope

region

Fig.

2-7.

Effect of

LEVEL/SLOPE

control

on CRT

display

(AUTO

P-P

MODE).

2-n

Operating

Instructions—

7B71

(SIM

B205000

and Up)

Horizontal

Sweep

Rate

The TIME/DIV

switch

provides

26

calibrated

sweep

rates

ranging from

0.02

microsecond/division

to

five

seconds/division.

The

VARIABLE

TIME/DIV

control

must

be in

the

calibrated

position

and the

MAGNIFIER

at XI

for the

indicated

sweep

rate.

The

VARIABLE

TIME/DIV

control

incorporates

a two-position

switch

to determine

if

the

sweep

rate is

calibrated

or

uncalibrated.

When

the

VARIABLE

knob

is in the

inward

position,

the

VARI-

ABLE

TIME/DIV

control

is

inoperative

and

the

sweep rate

is

calibrated.

When

pressed

and

released,

the

VARIABLE

knob

moves

outward

to

activate

the

VARIABLE

TIME/

DIV

control for

uncalibrated

sweep

rates.

A

calibrated

sweep

rate

can

be obtained

at

any position

of

the

VARI-

ABLE

TIME/DIV

control

by

pressing

in the

VARIABLE

knob.

This feature

is

useful

when

a specific

uncalibrated

sweep rate

has

been obtained

and it is

desired

to

switch

between

this

uncalibrated

sweep

rate

and a

calibrated

sweep

rate.

Switching

from

uncalibrated

to calibrated

operation

or

vice

versa does

not affect

the

setting of

the

VARIABLE

TIME/DIV

control.

The

VARIABLE

TIME/DIV

control

allows

the sweep rate in

each

TIME/DIV

switch

position

to

be reduced

to

at

least

the sweep

rate of

the

next

adjacent

switch

position. This

provides

an overall

uncalibrated

vari-

able

sweep

rate range

from 20

nanoseconds/division

(from

2

nanoseconds/division with

MAGNIFIER

at X10)

to about

12.5

seconds/division.

When

making

time

measurements

from

the

graticule,

the

area

between

the

second-division

and

tenth-division

vertical

lines

of the

graticule

provides

the

most

linear

time

measure-

ment

(see

Fig.

2-8).

Therefore,

the

first

and last

division

of

the

display

area

should

not

be

used when

making

accurate

time

measurements.

Position

the

start

of the

timing

area

to

the

second-division

vertical

line

(second

line

from

the

left)

and

adjust

the

TIME/DIV

switch

so the

end

of the

timing

area

falls

between

the

second-division

and

tenth-division

vertical

lines.

Sweep Magnifier

The sweep magnifier

expands the

sweep ten times. The

center division of the

unmagnified

display is the

portion

visible

on

the

screen in

magnified form

(see

Fig.

2-9).

Equivalent

length of

the magnified

sweep

is more than

100

divisions;

any

10-division

portion

can be

viewed by

adjusting

the horizontal

POSITION

control

to

bring

the

desired

portion

onto the

viewing

area.

The dual-range

feature of

the horizontal

POSITION

control

is particularly

useful

when the

MAGNIFIER

is set

to X10

(see Horizontal

Position

Control

discussion

which

follows).

To use sweep

magnification,

first

move

the

portion of

the

display which

is

to be expanded

to the center

of

the

graticule.

Then press

the

X10-MAGNIFIER

pushbutton;

the XI

0 button lights

to indicate

that the

horizontal

sweep

rate

is magnified.

Whenever

the

X10-MAGNIFIER

push-

Fig.

2-8.

Area of

graticule

used for

accurate

time

measurements.

4 '00m\

1

aops

(B)

Magnified

Waveform

Fig. 2-9.

Operation

of

sweep magnifier.

2-12

0

Operating Instructions—7B71 (SIM

B205000

and

Up)

button is lighted,

the equivalent magnified sweep rate can

be determined by

dividing the TIME/DIV switch setting by

10. For example,

if

the

TIME/DIV switch is set

to

.05

ys,

the equivalent

magnified sweep rate is

5

nanoseconds/

division. The equivalent

magnified

sweep

rate

must be used

for all time measurements when the

X10-MAGNIFIER

button is lighted.

The equivalent magnified

sweep

rate is

calibrated when

the VARIABLE TIME/DIV control

is in

the calibrated position.

Rufus P.

Turner,

"Practical

Oscilloscope

Flandbook",

Volumes

1 and

2,

John F.

Rider Publisher

Inc., New

York,

1964.

Measurement Techniques

Sweep Rates.

To

establish

an arbitrary

horizontal

sweep

rate based upon

a

specific

reference

frequency,

proceed

as

follows;

Horizontal Position Control

The 7B71

provides both

fine

and coarse adjustment

of

positioning. The coarse adjustment

provides rapid

horizon-

tal positioning

of the trace. Fine positioning

is

provided for

more precise control

of trace

position.

APPLICATIONS

General

The following

information

describes the

procedures

and

techniques

for making

basic

measurements

with a

7700-

series Oscilloscope.

These applications

are not described

in

detail, since each

application

must be adapted

to the

requirements of the individual measurement.

This instru-

ment can

also

be used

for many

applications not described

in this manual. Contact your local Tektronix Field Office

or representative

for

assistance in making specific measure-

ments. Also,

the following

books describe oscilloscope

measurement

techniques which

can be adapted

for

use with

this instrument:

Harley

Carter,

"An Introduction

to

the

Cathode

Ray

Oscilloscope", Philips

Technical

Library, Cleaver-Hume

Press

Ltd.,

London,

1960,

J. Czech, "Oscillosocpe

Measuring

Technique",

Phil-

ips Technical

Library,

Springer-Verlag,

New

York,

1965,

Robert

G.

Middleton and L.

Donald Payne, "Using

the Oscilloscope in Industrial

Electronics”, Howard

W.

Sams & Co. Inc.,

The Bobbs-Merrill Company Inc.,

Indianapolis, 1961

.

1.

Connect the reference

signal

to the INPUT

connec-

tor. Set

the VOLTS/DIV switch

for four

or five

divisions of

vertical deflection.

2.

Set the TIME/DIV

switch

and

the VARIABLE

TIME/DIV

control so one cycle of

the

signal covers

an

exact

number of horizontal

divisions.

Do not change

the

VARIABLE

TIME/DIV

control after

obtaining

the desired

deflection.

This display

can be

used as

a

reference

for fre-

quency

comparison

measurements.

3.

To

establish

an arbitrary

sweep rate

so the repetition

rate of

an unknown

signal

can be

measured

accurately

at

any setting of

the TIME/DIV

switch,

the

repetition

rate of

the reference

signal

must be

known. If

it

is

not known,

it

can

be

measured before

the

VARIABLE

TIME/DIV

switch

is set

in step 2.

4.

Divide

the repetition rate of

the reference

signal

(seconds)

by

the

product of

the horizontal

deflection

established

in step

2

(divisions)

and the setting

of

the

TIME/DIV

switch. This is the

horizontal

conversion

factor:

Horizontal

Conversion

=

Factor

reference signal repetition

rate (seconds)

horizontal

deflection

(divisions)

TIME/DIV

switch

setting

5.

To measure

the

repetition

rate of

an unknown

signal,

disconnect

the reference

signal

and

connect the

unknown

signal

to the INPUT

connector.

Set

the TIME/DIV

switch

to a setting

that

provides sufficient

horizontal

deflection

to

make

an accurate

measurement.

Do

not

readjust the

VARI-

ABLE

TIME/DIV

control.

John

F. Rider and

Seymour

D, Uslan,

"Encyclopedia

of

Cathode-Ray

Oscilloscopes

and Their

Uses",

John

F.

Rider Publisher

Inc.,

New

York,

1959.

6.

Measure the

horizontal

deflection

in divisions

and

calculate the repetition

rate

of

the unknown

signal using

the

following

formula:

John F. Rider,

"Obtaining

and

Interpreting Test

Scope Traces”,

John F. Rider Publisher Inc., New York,

1959.

Repetition

Rate

TIME/DIV

switch

X

setting

horizontal

horizontal

conversion

x

deflection

factor

(divisions)

a

2-13

Operating

lnstructions-7B71

(SN

B205000

and

Up)

NOTE

If the

horizontal

magnifier

is used,

be sure

to

use the

magnified

sweep

rate in

place

of

the TIME/DIV

switch

setting.

Example.

Assume

a reference

signal

frequency

of

455

hertz

(repetition rate

2.19

milliseconds),

a TIME/DIV

switch

setting of

.2 ms,

and the

VARIABLE

TIME/DIV

control

adjusted

to provide

a

horizontal

deflection of

eight

divisions.

Substituting

these

values

in the

horizontal

conver-

sion factor

formula

(step

4):

6.

Adjust the vertical

POSITION

control

to

move

the

points

between

which the

time

measurement

is made

to the

center

horizontal

reference

line.

7.

Adjust the

horizontal

POSITION

control

to

position

the

time-measurement

points

within

the

center

eight

divi-

sions of

the graticule.

8. Measure

the horizontal

distance

between

the time

measurement

points. Be

sure

the

A VARIABLE

control is

set to

CAL.

Horizontal

Conversion

=

Factor

2.19

milliseconds

.2X8

=

1.37

9. Multiply

the distance

measured

in step

8

by the set-

ting of the TIME/DIV

switch.

If

sweep

magnification

is

used,

divide this answer

by 10.

Then, with

a

TIME/DIV

switch

setting

of

50

ys, the

repetition rate of

an unknown

signal

which

completes

one

cycle in

seven horizontal

divisions

can be

determined

by

using the repetition

rate

formula

(step

6):

Example.

Assume

that the

distance

between the

time

measurement points

is

five

divisions

(see

Fig.

2-10), and the

TIME/DIV

switch

is set

to

.1

ms with

the magnifier

at XI.

Using

the formula:

Repetition

Rate

50

ys

X 1.37 X

7

=

480

ys

Time

Duration

=

horizontal

distance

)(

(divisions)

TIME/DIV

setting

magnification

This answer can be converted

to frequency

by taking

the

Substituting

the

given

values:

reciprocal

of the repetition

rate (see

application on Deter-

mining Frequency Measurements).

5 X 0 1 ms

Time Duration

=

r

Time-Duration

Measurements

To measure time between

two points on

a

waveform,

use

the

following

procedure:

1 . Connect

the

signal to either

Vertical plug-in.

2. Set the MODE

switch

to display the

plug-in used.

3.

Set

the VOLTS/DIV

switch

to display about

four

divisions of

the waveform.

4.

Set the

A Triggering

controls

to obtain

a

stable

display.

5.

Set

the TIME/DIV

switch

to the fastest

sweep

rate

that

displays

less than

eight

divisions

between

the

time

measurement

points

(see Fig.

2-8).

(See

the

topic entitled

Horizontal

Sweep

Rate

in this

section

concerning

non-

linearity

of first

and last

divisions

of

a display.)

The

time

duration

is

0.5

milliseconds.

2-14

Operating

lnstructions-7B71

ISN B205000 and

Up)

Determining Frequency

The time

measurement technique

can also

be

used to

determine the

frequency of

a signal. The frequency of

a

periodically recurrent signal is the reciprocal of

the time

duration (period) of

one

complete

cycle.

Use the following procedure:

1.

Measure the time duration of

one complete

cycle

of

the waveform

as

described

in the previous

application.

2.

Take the reciprocal of

the time

duration

to determine

the

frequency.

Example.

The frequency

of

the signal

shown

in Fig.

2-10

which has

a

time

duration of

0.5 milliseconds

is;

1

1

Frequency

=

:

:

—

=

2 kilohertz

time duration

0.5

ms

Risetime

Measurements

Risetime

measurements

employ

basically

the

same

techniques

as

time-duration

measurements.

The

main differ-

ence

is the points

between

which the

measurement

is

made.

The following

procedure gives

the

basic

method

of

meas-

uring

risetime between

the 10%

and

90%

points

of the

waveform. Falltime

can be

measured

in the

same

manner

on

the

trailing edge of

the

waveform.

1 . Connect

the signal

to either

Vertical

plug-in.

2. Set

the MODE

switch

to

display the

plug-in

used.

3.

Set

the VOLTS/DIV

switch and the

VARIABLE

control

to

produce

a signal

an exact number of divisions

in

amplitude.

4. Center the

display

about the center horizontal

line

with

the vertical

POSITION

control.

5.

Set the

A

Triggering

controls

to obtain

a stable

display.

6.

Set

the TIME/DIV

switch

to the

fastest

sweep

rate

that

displays

less

than eight

divisions

between the

10% and

90% points

on the waveform.

7.

Determine

the

10% and

90% points

on the rising

por-

tion of

the

waveform.

The figures

given

in Table

2-1

are for

the

points

10%

up from

the start

of

the rising

portion

and

10%

from

the

top of

the rising

portion

(90%

point).

TABLE

2-1

Risetime

Measurements

Vertical

display

(divisions)

10%

and 90%

points

Divisions

vertically

between

10%

and

90% points

4

0.4

and

3.6 divisions

3.2

5

0.5

and 4.5

divisions

4,0

6

0.6 and

5.4

divisions

4.8

8.

Adjust

the

horizontal

POSITION

control

to move

the

10%

point of

the

waveform

to the

second

vertical

line of

the graticule.

For

example,

with

a

five-division

display

as

shown

in Fig.

2-11,

the

10%

point

is 0.5

division

up from

the

start of

the rising

portion.

Fig. 2-11.

Measuring risetime.

9.

Measure

the

horizontal

distance

between

the

10%

and

90%

points. Be

sure the

A

VARIABLE

control

is set

to

CAL.

10.

Multiply

the

distance

measured

in

step

9 by

the

setting

of

the

TIME/DIV

switch. If

sweep

magnification

is

used,

divide

this answer

by 10.

Example.

Assume

that

the

horizontal

distance

between

the

10%

and

90%

points

is four

divisions

(see Fig.

2-1

1 )

and

E

2-15

Operating

lnstructions-7B71

(SN

B205000 and

Up)

the TIME/DIV

switch

is set

to

1

ys

with

the MAG

switch

set

to X10.

Applying

the time

duration

formula

to risetime:

Time Duration

(Risetime)

horizontal

distance

^

(divisions)

TIME/DIV

setting

magnification

3. Set the

A TIME/DIV

to

a

sweep

rate which

displays

about six

divisions between

pulses. Adjust the

A Triggering

controls for

a stable

display.

4. Set

the

A

Time-Base

B DELAY

MODE selector

to B

STARTS AFTER

DELAY.

Substituting

the

given values;

Risetime

=

4 X

1

ys

10

5.

Set the

B Time/div

to a setting

1/100

of

the A TIME/

DIV

sweep rate.

This produces

an intensified

portion

about

0.1 division

in length.

The risetime

is 0.4

microsecond.

Delayed

Sweep Time

Measurements

The delayed

sweep

mode

can be used

to make accurate

time

measurements.

The following

measurement

determines

the time difference

between

two pulses

displayed on the

same trace.

This

application

may also

be used

to measure

time difference

from

two

different

sources (dual-trace)

or

to measure

time

duration of

a single

pulse. See Section

one

for

measurement

accuracy.

1. Connect

the signal

to

either

vertical plug-in. Set the

Indicator

Oscilloscope

vertical MODE selector

to display

the

plug-in being used.

Set the horizontal

MODE selector

to

CHOP or

ALT (see Oscilloscope

Manual discussion on hori-

zontal

mode switching)

to display both Time-Base sweeps.

2. Set the

VOLTS/DIV selector

to

produce

a

display

about three divisions in

amplitude (see

Fig. 2-12).

NOTE

Do not change

the 4

LEVEL control

setting or the

horizontal

POSITION

control setting

in the following

steps, as the

measurement

accuracy will

be affected.

6.

Turn the

DELAY-TIME

MULTIPLIER

dial

to move

the

intensified

portion of the

A sweep

to the

first

pulse.

7.

Adjust

the DELAY -TIME

MULTIPLIER

dial

to move

the

pulse

(or rising

portion) of

the B sweep

to the center

vertical

line. Note

the setting of

the

DELAY-TIME

MULTI-

PLIER

dial.

8.

Turn

the DELAY-TIME

MULTIPLIER

dial

clockwise

until

the second

pulse

is positioned

to

this

same point (if

several

pulses are

displayed,

observe the intensified

portion

of

the

A sweep

to locate

the correct

pulse).

Again note

the

dial

setting.

9.

Subtract

the

first

dial setting from the second and

multiply

by

the delay time shown

by

the

A

TIME/DIV

selector. This

is

the time

interval between the pulses.

Example:

Assume the

first

dial setting is 2.23 and the

second

dial setting is 7.73 with the TIME/DIV set to

5

ys

(see Fig. 2-13).

Using the formula;

Time Difference

(delayed sweep)

second dial

setting

first dial

setting

delay time

(A

TIME/DIV

setting)

Substituting

the given values:

Fig.

2-12.

Measuring time difference

using

delayed

sweep. Time Difference

=

(7.73

-

2.23)

X

5

ys.

Operating

Instructions—

7B71 (SN

B205000 and Up)

Fig. 2-13.

Using

delayed sweep for

sweep

magnification.

The

time

difference

is

27.5

microseconds.

5.

Position

the start of the intensified

portion with

the

DELAY

-TIME MULTIPLIER

dial to the part of the

display

to be magnified.

6.

Set

the B TIME/DIV

to

a

setting

which intensifies

the

full

portion

to be

magnified. The

start

of

the

intensified

trace

remains

as positioned

above.

7.

Time

measurements

can be made from

the display

in

the

conventional

manner. Sweep

rate is

determined

by the

setting

of the

B TIME/DIV

selector.

Example:

The apparent

magnification of the

display

shown in Fig.

2-13

with

an A TIME/DIV

setting of

.1 ms

and a

B TIME/DIV setting

of

1

l_ls

is:

Apparent

Magnification

_

A TIME/DIV

setting

(Delayed

Sweep)

B

TIME/DIV

setting

Delayed

Sweep Magnification

The delayed

sweep feature

of the

7B71

can

be

used

to

provide

higher apparent

magnification

than is

provided

by

the MAG

switch. The

sweep rate of

the DELAYED

SWEEP

(B sweep) is

not actually

increased; the

apparent

magnifica-

tion is the

result of delaying

the

B sweep an

amount of

time

selected

by the A TIME/DIV

switch and

the DELAY-TIME

MULTIPLIER

dial before

the display

is

presented

at the

sweep rate

selected

by the

B TIME/DIV

switch.

The fol-

lowing

method

uses the

B STARTS AFTER

DELAY

posi-

tion to allow

the

delayed

portion

to be positioned

with

the

DELAY-TIME

MULTIPLIER

dial. If

there

is too

much

jitter in

the delayed

display,

use the Triggered

Delayed

Sweep

Magnification

procedure.

1.

Connect

the

signal

to either vertical

plug-in.

Set the

Indicator

Oscilloscope

vertical

MODE

selector

to display

the plug-in

used

and the

horizontal

MODE

to CFIOP

or

ALT

to display

both Time-Base

sweeps.

2.

Set

the

VOLTS/DIV

selector to

produce

a display

about three

divisions

in

amplitude.

3. Set

the A

Time-Base

B DELAY

MODE

selector

to B

STARTS AFTER

DELAY.

Adjust

the

A Triggering

controls

for

a stable

display.

4. Set the A

TIME/DIV to a

sweep

rate which

displays

the

complete

waveform.

Substituting

the

given

values:

Apparent

Magnification

The

apparent

magnification

is 100

times.

Triggered

Delayed

Sweep

Magnification.

The

delayed

sweep

magnification

method

just

described

may

produce

too

much

jitter

at high

apparent

magnification

ranges.

The

B

TRIGGERABLE

AFTER

DELAY

position of

the

B

DELAY

MODE

selector

provides

a more

stable

display,

since

the delayed

display

is triggered

at the

same

point

each

time.

1. Set

up the

display

as

given in

steps

1 through

6

above.

2.

Set

the

B

DELAY

MODE

selector

to

B TRIGGER-

ABLE

AFTER

DELAY.

3.

Adjust

the

B LEVEL

control

so the

intensified

por-

tion

on the trace

is stable.

4.

Inability

to intensify

the desired

portion

indicates

that the

B Triggering

controls

are

incorrectly

set or

the

1 X

KJ-'’

1 X

10-*^

100

Operating

lnstructions-7B71

(SN B205000

and

Up)

signal

does

not meet the

triggering

requirements. If

the

condition

cannot

be remedied

with the

B Triggering

con-

trols

or

by increasing

the display

amplitude

(lower

VOLTS/

DIV

setting),

trigger the

B

sweep

externally.

5. Measurement

and

magnification

are as

described

above.

Displaying

Complex

Signals

Using Delayed

Sweep

Complex

signals often

consist of

a

number of

individual

events of

differing

amplitudes.

Since the

trigger circuits

are

sensitive

to changes in

signal

amplitude,

a stable

display

can

normally

be obtained

only

when the

sweep is

triggered

by

the

event(s)

having

the greatest

amplitude.

However,

this

may

not produce

the

desired

display of

a

lower-amplitude

portion

which follows

the triggering

event.

The

delayed

sweep

feature

provides

a

means of

delaying

the start of

the

B sweep

by a selected

amount following

the

event

which

triggers

the

A Sweep

Generator.

Then,

the part of

the wave-

form

which

contains

the information

of

interest

can be

displayed.

Use the

following

procedure:

1. Set

up the

display

as

given

in Delayed

Sweep Magni-

fication

Steps

1 through

6.

2.

Time

measurements

can be

made from the

display

in

the

conventional

manner.

Sweep rate is

determined

by the

setting of

the

B TIME/DIV

selector.

Example.

Fig.

2-14

shows

a complex

waveform

as

dis-

played

on the

CRT.

the circled

portion

of the

waveform

cannot

be viewed

in

any greater

detail

because

the sweep

is

triggered

by the larger

amplitude

pulses

at the

start

of

the

display

and

a

faster

sweep

rate

moves this

area

of

the

wave-

imnnnini^nTnni]!

TiiiTrrnmniiTmTmimw

mnimnn

imiirnfm

msmtsm

iWiilMftli

ismmam

HBIBII!

»

Fig.

2-14.

Displaying

a complex

signal using

delayed

sweep.

form

off

the

viewing area.

The

second

waveform

shows

the

area

of

interest

magnified

500 times

using

Delayed

Sweep.

The

DELAY-TIME

MULTIPLIER

dial has

been

adjusted

so

the delayed

sweep

starts

just

before

the

area of

interest.

Pulse

Jitter

Measurements

In

some

applications

it is

necessary

to

measure

the

amount

of

jitter

on the

leading

edge

of a

pulse

or jitter

between

pulses.

1

. Set

up the display

as in the

above procedure.

2. Set

the B DELAY

MODE

selector

to

B STARTS

AFTER

DELAY.

Slight

readjustment

of

the B Triggering

A

V

:

5

JfiS

oo s

f

•

-

1

h

1

__

1

;

4

^

-0.5

divisfc

>n

1

4

Fig. 2-15.

Measuring

pulse jitter.

LEVEL

control may be

necessary

to produce

as stable

a

display

as possible.

3.

Pulse

jitter is shown

by horizontal

movement

on the

pulse

(take into

account

inherent jitter

of Delayed

Sweep).

Measure

the amount of

horizontal

movement.

Be sure

both

VARIABLE

controls are

set

to CAL.

4.

Multiply

the distance

measured

in

step

3 by the

B

TIME/DIV

switch

setting

to obtain

pulse

jitter in

time.

Example.

Assume

that

the

horizontal

movement

is

0.5

divisions

(see Fig.

2-15), and the

B TIME/DIV

switch

setting

is

.5

ys.

Using

the

formula:

Pulse

Jitter

=

horizontal

jitter

X

(divisions)

B TIME/DIV

setting

Substituting

the given values:

Pulse

Jitter

=

0.5 X

0.5

ys

The

pulse

jitter

is 0.25

microseconds.

2-18

iS

7B71 (SN B205000and Up)

SECTION

3

CIRCUIT DESCRIPTION

Change

information

,

if any, affecting

this section

will

be

found

at the

rear of the manual.

Introduction

This

section

of

the manual contains

a description

of the

circuitry

used in the

7B71. Detailed block

diagrams

are

used to show the interconnections

between

the

stages in

each major

circuit and the relationship

of

the front-panel

controls to

the individual stages.

A complete

block diagram

is located

in the

Diagrams

Section at the rear of this

manual. This

diagram

shows the

overall

relationship between

all of the

circuits.

Complete

schematics of

each circuit are also

given

in the Diagrams

Section. Refer

to these diagrams

throughout

the following

circuit

description for electrical

values

and relationship.

BLOCK

DIAGRAM

General

The following discussion of

the block

diagram

at the

rear

of this manual is provided

to aid in

understanding

the over-

all concept of

the 7B71 before

the individual

circuits

are

discussed in detail.

Each block

represents

a major

circuit

within

this instrument.

The selection

of INTERNAL

or

EXTERNAL

triggering

is made

in the Trigger

Input circuit.

This

stage also sets

the

gain

and DC balance

of the

external trigger

input.

To in-

crease the

range of

the external

trigger

input,

a 10X atten-

uator

network

is incorporated

in the input of

the

external

trigger

amplifier.

The Trigger

Amplifier

circuit

provides

amplification

and

waveshaping of

the selected

input

trigger signal.

Level cen-

tering, slope

selection

and

coupling

controls are

contained

in this circuit.

The Peak

Detector

provides

the logic

necessary for

P-P

AUTO

mode operation.

The

peak sensing

circuits set

the

range of

the LEVEL

control to

allow triggering

over

most

of

the range of

the input

signal.

This

circuit contains level,

mode, coupling

and

source controls.

The Trigger

Generator circuits

produce

an output

pulse

which

initiates the

sweep signal

produced

by sweep

gener-

ator circuits.

The sweep

gate multivibrator

produces

a

Sweep

Gate

for

use by

the indicator

oscilloscope.

The

bright-line

auto feature

which provides

a free-running

trace

in the absence of

triggering

signals is

contained in this

stage.

The

TRIG'D light

is also connected

to

the bright-line auto

circuit to indicate

the presence

of a trigger

signal.

The

Sweep Generator

circuit

produces

a linear

sawtooth

output signal

when initiated

by the

trigger

generator. The

slope

of the

sawtooth

produced

by the sweep generator

is

controlled

by the TIME/DIV

switch setting.

The operating

mode of

the sweep

generator

is controlled

by

the TRIG-

GERING

MODE

switch. In

the P-P

AUTO

and

AUTO posi-

tions,

the absence

of

a trigger

signal

causes

the sweep

to

free run.

In

the NORM

position,

a horizontal

sweep

is

initi-

ated

only

when

triggered by

an adequate

trigger signal.

The

SINGLE

SWEEP

position

allows

only

one

sweep to be initi-

ated

after

the circuit

is reset

with

the

RESET

button or

by

the

remote reset

control.

The

Horizontal

Preamp

is

a

single-ended

to

push-pull

amplifier.

The output

of

the

sweep

generator

circuit

is

amplified

by this

circuit

to

produce

horizontal

deflection

for the

oscilloscope.

This circuit

contains

a

10

times

magni-

fier

to increase

the

sweep

rate

ten

times

in

any TIME/DIV

switch

setting.

Horizontal

positioning

is incorporated

in this

stage.

DETAILED

CIRCUIT

DESCRIPTION

General

The following

circuit

analysis

is written

around

the

detailed block

diagrams

which are

given for

each

major

cir-

cuit.

These detailed

block

diagrams

give

the

names of

the

individual

stages

within

the major

circuits

and

show how

they are

connected

together.

The block

diagrams

also

show

the

inputs

and

outputs

for each

major

circuit

and

the rela-

tionship

of the front

panel

controls to

the

individual

stages.

The

names

assigned

to

the

individual

stages

on

the detailed

block

diagrams

are

used

throughout

the following

discus-

sion.

TRIGGER

INPUT

Input

Source

The

internal

trigger signal

from

the

vertical deflection

system

is coupled

directly through

this stage

to the

trigger

Circuit

Description-7871

{SN

B205000

and Up)

amplifier.

The external trigger

signal

can be AC or

DC

coupled

to the external

input amplifier.

See

Fig.

3-1

for

a

simplified

block

diagram of the

Trigger Input

Stage.

External Input

Amplifier

The

external signal

is converted from

single-ended

to

push-pull

by paraphrase

amplifier

Q20A

and Q20B. The

gain of

this amplifier

is set by R25

for

a push-pull gain of

0.2.

R37 is used to

DC balance the

output and

is adjusted

for

a

voltage

null between

the

push-pull output

lines. A

divide-by-10

attenuator

network

in the

input to this ampli-

fier

can be selected

by the front

panel

EXT

-i-

10

push-

button

to extend

the triggering level

range

of the unit.

TRIGGER

AMPLIFIER

General

The

Trigger Amplifier circuit

provides

slope and level

selection of

the trigger signal

applied to the

Trigger

Gener-

ator.

The P-P AUTO

feature is also

incorporated

in this

circuit.

Other controls

provided in

this circuit

are AC LF

REJ,

DC,

AC HF REJ

and LINE

TRIGGERING

SOURCE.

Fig.

3-2

shows a

detailed block

diagram

of

the Trigger

Amplifier

circuit.

A schematic

of

this

circuit is shown

on

diagrams

2

and 3 at the

rear of

the

manual.

Input

Stage

The

trigger

signal

(internal

or

external

as selected

by the

SOURCE

switch)

is

applied

push-pull

to the

bases of

0107

3-2

Circuit

Description—

7B71

(SISI

B205000

and Up)

!

1

i

!

1

1

i

1

1

!

V.

S.

/

^ •

AC

LF

REJ

DC

LEVEL/SLOPE

Fig.

3-2.

Simplified block

diagram of

the trigger amplifier.

and Q108. Impedance

compensating

networks R100, Cl

00,

LlOOand R101

at

the base of Q107

and R104,C104,

L104

and R103 at the base of

Q108 provide a

50

ohm

input for

the trigger

signal.

Q126 with voltage

divider network R126,

R127,

R128 provides a DC reference

level for

Q1 16.

Q120,

R119,

R120, R121, R122

and the output

of the

peak

detector

circuit provides

a

variable

voltage

source for

Q1 10.

R121

is adjustable to DC balance

this

stage with

the

LEVEL control

set

to the 9:00

o'clock

position of

rotation

(centered

on

the

positive

slope).

Q110-R111 and

Q1

16-R1

17

provide the current

source for Q107

and Q108

respectively.

The AC HF REJ

control, located

in the output

of

the

cascode Input

Stage, engages Cl

38 through relay K138

to

provide attenuation of

signals above

50 kHz.

Peak

Detector

The triggering

level, with

the MODE

switch set

to

P-P

AUTO is controlled

by

the

Peak

Detector

stage. The

signal

from the

trigger amplifier

input

stage is applied

to the Peak

Detector

peak sensing

network.

The output

of the Peak

Detector

sets the voltage

applied

to the

LEVEL control

(R146A)

so that

the range of

the LEVEL

control corre-

sponds to the

peak-to-peak

amplitude

(or less) of the

input

signal.

The

positive portion

of the input

signal is

inverted

by

the trigger input

stage and

applied

through

CR210 to the

peak sensing network.

C210

charges to

the peak value

of

the input

signal. The

signal is amplified

by Q220-Q224

and

applied to the

gate

of

source

follower

Q248.

Current

through Q248

decreases and

the

voltage

at the

wiper of

R251

becomes more

negative.

This

negative-going

signal

is

inverted

by operational

amplifier

U260,

and applied

to

the

top of

LEVEL

control R146A.

The negative

portion of

the input

signal is applied

in-

phase to the

Peak

Detector. The

operation of the

peak

sensing network is the same as that

described for the

peak

positive sensing

network.

The output

at the source of

Q255

is applied to the bottom of

LEVEL control

R146A,

as a

negative-going voltage which

represents

the

peak negative

value

of the

signal

input.

At the end of the positive

input

signal the voltage

at the

source of Q248

rises at

a

rate

determined

by

C248 and

R241. The feedback

from the

source of

Q248 aids

in hold-

ing the charge

on C210. For

signals

with

a

repetition

rate of

about 200 hertz

or greater,

the

peak sensing

network will

remain charged

to the

peak level of

the input

signal.

MODE, COUPLING and SOURCE

controls are included

in the output stage

of

the

Peak Detector.

Slope

Comparator

The Slope Comparator is the electronic

equivalent of a

double-pole double-throw switch.

With the SLOPE

switch

set for positive slope triggering,

01

58-01

59

are

on and

Q161-Q168-Q169

are off. For

negative slope triggering,

Q161-Q168-Q169

are on and Q158-Q159

are

off.

R155

adjusts the

negative

P-P

AUTO

triggering when

the LEVEL/

SLOPE

control is

set to the negative

slope.

a

3-3

Circuit

Description-7B71

{SN

B205000

and Up)

Output

Stage

The

output of the

slope

comparator

is applied

through

the

Output Stage

to the

trigger

generator

circuit.

Diodes

CR181

and CR182

limit

the push-pull

output

of the

trigger

amplifier

to about

one volt

peak-to-peak.

TRIGGER

GENERATOR

Trigger

Pulse

Generator

The Trigger

Pulse

Generator

(see

Fig.

3-3) shapes the

output of

the Trigger

Amplifier

to

provide

a trigger

pulse

with a fast leading

edge.

Tunnel diode

VR304

is quiescently

in its low-voltage

state. The

signal

from

the

Trigger

Ampli-

fier switches

it to

its high-voltage

state,

causing

a negative-

going

fast rise

pulse

at the

base of

0317

and

a positive-

going pulse

at the

base of

0309.

The

output

of the

Trigger

Pulse

Generator

at the collector

of

0317

is

a

positive-going

fast

rise

pulse which

is

applied

to

the

Sweep

Gate Stage.

The

output

at the

collector

of

0309

is

a

negative-going

pulse

which is

applied

to

the

bright-line

Auto

circuit.

VR304

reverts

back to its

low-voltage

state

when the

signal

from

the

Trigger Amplifier

decreases

sufficiently.

VR304

runs at

the repetition

rate of

the

input

signal.

Sweep Gate Stage

The Sweep Gate Stage produces

a negative-going step

to

start the

Sweep

Generator and a positive

gate for use in

the

oscilloscope.

The positive-going

pulse from

the

Trigger Pulse Gener-

ator

enables

CR319, opening

an additional

current

path for

VR358,

the

sweep gate tunnel

diode.

VR358 switches

to its

high-voltage

state, applying

a positive

signal to

the base of

Q360 (part of

the bistable

sweep

gate multivibrator).

The

collector

voltage

of Q360

decreases,

producing the

negative-

going

step used

to enable the

the Sweep

Generator.

When

Q360 turns

on, emitter-coupled

Q368 is

turned off

to pro-

duce

the positive

edge of the

sweep

gate output.

The sweep

gate

multivibrator remains

in

this state

(Q360 on and Q368

off)

until

it

is

reset

by the sweep

reset

multivibrator (part

of

the

Sweep Generator)

at the

end of the

sweep.

At the

end of the

sweep, the

negative-going

lockout

gate

from

the sweep reset

multivibrator

is

applied

to the base of

Q326 turning

it off.

Emitter-coupled

Q328 is

turned on,

taking

current from

the

sweep

gate tunnel

diode,

VR358,

and

reverting it

to its low-voltage

state.

This switches

the

sweep

gate multivibrator

back

to its

quiescent

state

(Q360

off

and Q368 on).

The circuit

remains

in

this condition

(VR358

in its low-voltage

state) until

the lockout

gate

re-

turns

to its high level

at the

end of holdoff

time.

Triggered Holdoff Stage

The Triggered Holdoff

Stage

rearms

the

sweep

gate TD,

VR358,

at

the end of holdoff

time. During

holdoff

time

VR322

is in its

high-voltage

state, biasing Q326 off.

At

the

end of holdoff time the lockout gate from the sweep reset

multivibrator returns to its high level.

This switches

VR322

3-4

Circuit

Description-7B71

(SN

B205000

and Up)

to its

low-voltage

state, turning

Q326

on.

Q328,

which is

emitter-coupled

to

Q326,

is turned

off

to rearm

the

sweep

gate TD, VR358.

At high

frequencies,

double triggering

could occur

due

to the finite

risetime

of the

lockout

gate

as it returns

to its

high level.

To reduce

the

incidence

of

double

triggering

of

the

circuit,

the trigger

pulse from

Q317

is

differentiated

by

C324-R324

and

superimposed

on

the

lockout

gate

at the

cathode

of

VR322.

Now

the sweep

is

rearmed

by

one

trigger

pulse

and triggered

by

the

following

trigger

pulse,

maintaining

the

proper

time

relationship

between

input

signal

and

the start

of the

sweep.

Bright

Line Auto

The

operation of the sweep

gate stage

in the P-P

AUTO

and AUTO MODE

is the same

as for

NORM MODE

just

described

when an adequate

trigger

signal is

present.

How-

ever, when

a

trigger signal

is

not present,

a free-runnning

trace

is produced

in the P-P

AUTO

and

AUTO

MODES.

With

no trigger signal

applied

to the

circuit,

0331, 0338

and

0339 are off. This

allows

C339

to charge

toward

the

positive 15

volt supply. As

the

top of

C339

becomes

more

positive, CR342

is turned

on,

making

the

base of

0346

move positive

to cutoff.

Emitter-coupled

0350

is turned

on

and the

additional

current

through

VR358

switches

the TD

to its high

voltage

state,

automatically

retriggering

the

sweep

each time

the lockout

gate

goes to

its high

level.

The

result

is that

the

sweep

generator

circuit

is

automatically

retriggered

at the

end of

each

holdoff

period

and

a free-

running

trace is

produced.

Since

the trace

free-runs

at the

sweep rate

of

the sweep

generator

circuit

(as selected

by the

TIME/DIV

switch),

a bright

reference

trace

is

produced

at

all sweep

rates.

The

sweep

TRIGGERED

lamp

will

not

be

lit,

indicating

an

untriggered

condition.

The

sweep TRIGGERED

lamp

is lit

each time

an ade-

quate

trigger signal

is applied

to the Pulse

Generator.

When

the

trigger

signal switches

VR304

to

its high-voltage

state,

Q309

is turned

off. This

turns

on

Q331,

Q338

and

Q339.

The top of

C339 becomes

less

positive,

turning off

CR342.

Q346

is turned

on and its

collector

goes

positive,

turning

on

Q348.

Q348

collector

current

lights

the

sweep

TRIG-

GERED

lamp.

When

Q346

turns on,

its

emitter voltage

decreases

and

emitter-coupled

Q350

is turned

off

to discon-

nect the

bright

line

auto circuit

from

the

sweep gate

stage.

When the

TRIGGERING

MODE

switch is in

the NORM

or

SINGLE

SWEEP

position,

the

anode of

CR355

is

clamped

to

ground.

This

reverse-biases

CR355

and discon-

nects

the

bright

line

auto

circuit

from the

sweep

gate

stage

but

allows

the

TRIG'D

light

to

function.

TIME-BASE

GENERATOR

General

The

Time-Base

Generator

circuit

(see

Fig.

3-4)

produces

a

sawtooth voltage

which is

changed

from

single-ended

to

push-pull

by the

Horizontal

Preamp

and

used

by the Indi-

cator

Oscilloscope

to provide

horizontal

sweep

deflection

on the CRT.

In

addition,

this circuit

produces

various

con-

trol signals

for

use by the

Indicator

Oscilloscope

as well

as

internal

signals for

use in the

Plug-in.

Normal

Trigger

Operation

Disconnect

Amplifier.

The

Disconnect

Amplifier,

0526,

is

quiescently

conducting

current

through

R523

and

the

Timing

Resistor,

R530.

The

negative-going

step from

the

Sweep Gate

Multivibrator

is

applied

to the

base of

the input

emitter-follower,

0404. 0404

couples

the

negative

step

to

the emitter

of Disconnect

Amplifier

0526,

turning

it

off.

The

timing

current

through

Timing

Resistor R530,

now

starts to charge Timing

Capacitor

C530,

enabling the

Sweep

Generator.

The

Disconnect

Amplifier

is

a low

leakage

transistor

to

improve

timing

at low

sweep

rates

and high

temperatures.

At

the end of

the sweep

0526

turns

on, discharging

the

Timing

Capacitor.

CR526

provides

isolation

between the

Disconnect

Amplifier

and

the

input

emitter-follower

during

holdoff

time.

Sawtooth

Sweep Generator.

The

basic sweep

generator

circuit is

a Miller Integrator

Circuit.’

The

current

flow

through

the Disconnect

Amplifier

is interrupted

by

the

signal from

the Sweep

Gate

Stage.

Timing

Capacitor

C530

now begins

to charge

through

Timing

Resistor

R530.

The

Timing

Resistor

and Timing

Capacitor

are

selected

by

the

TIME/DIV

switch

(a

front

panel

control)

to

provide

sweep

rates

as listed

on the front

panel.

As the

Timing

Capacitor

begins

to charge

toward

the

voltage

applied to

the Timing

Resistor,

the

gate of

Q532A,

which

is

tied to the

junction

of

R530-C530,

goes negative

by the same amount.

This decreases

the current through

Q532A, forcing

more

current

through

Q532B. This

increase

in

Q532B drain

current

flowing

through

R534

gives

a

negative-going

voltage

at the

base

of Q533.

This causes

the

collector

of

Q534

to pull up.

The

positive

side of

the

Timing

Capacitor, being

tied

to

the

collector

of

Q534,

is

also

pulled up.

This

action

results

in

a positive-going

voltage

being

applied

across

the Timing

Capacitor

maintaining

a

constant

charging

current

and

giving

a linear rate

of rise

to

the

sawtooth

output

signal. The

sawtooth

output

signal

continues

to rise

in this

manner

until

the

Sweep

Gate

Multivibrator

is

switched

to turn

on the

Disconnect

Amplifier.

’

Jacob

Millman

and Herbert

Taub,

"Pulse,

Digital

and

Switching

Waveforms",

McGraw-Hill,

New

York,

1965,

pp.

540-548.

3-5

Circuit Description—

7B71 (SN

B205000 and Up)

DELAY

MULTIVIBRATOR

Q482,

Q492

DELAY

COMPARATOR

0510,

0520

DELAY MODE

SELECTOR

S490

DELAY

DELAY GATE

GATE

E.F^^>

*-

TO OSCILLOSCOPE

0496

DELAY MODE CONTROL

SAWTOOTH

SAWTOOTH~

^

SWEEP

AMPLIFIER^^^

0546

TO

OSCILLOSCOPE

TO

OSCILLOSCOPE

SWEEP START

GATE

SAWTOOTH

DISCONNECT

SWEEP

AMPLIFIER

1>

GENERATOR

0526

L 0532

0533

S

ny

0534 0537

SAWTOOTH

^

TO

HORIZONTAL

PREAMP

SWEEP START

AMPLIFIER

0592

SWEEP STOP

COMPARATOR

0406,

0408

RESET

TO

SWEEP

GATE STAGE

SWEEP RESET

multivibrator'

0432,

0436

REMOTE

READY

LIGHT

SWEEP

HOLDOFF

MULTIVIBRATOR!

0554,

0564

0566

HOLDOFF

AMPLIFIER

AND CAPACITOR

0582, C580

HOLDOFF

—

TO

OSCILLOSCOPE

HOLDOFF

DISCONNECT

DIODE

CR571

SWEEP INHIBIT

DELAY MODE CONTROL

Fig.

3-4.

Sweep Generator

block diagram.

Circuit

Description—

7B71

(SN

B205000

and Up)

The sawtooth output from

the collector of

Q534 is con-

nected

to the Horizontal

Preamp, the

Delay Pickoff

circuit,

and through R539

to the Sweep

Start Amplifier,

Sweep

Stop Comparator, and through

amplifier Q546

to the Indi-

cator Oscilloscope. CR528-CR529

protects

against

gate-

source breakdown of

Q532A.

Sweep Start

Amplifier.

Delay start

adjustment R590

adjusts

the

base

voltage of

Q592A to set the

quiescent volt-

age

of

the sawtooth. The collector current of

Q592A, flow-

ing through R523, establishes

the correct starting

point of

the sawtooth output signal. L593-R593

prevent oscillations

at the faster

sweep

rates.

They are shorted

out at the slower

sweep

rates.

CR596 A & B prevent

base-emitter breakdown

of

Q592 A & B.

The

sawtooth

output signal

is applied through

R539

to

the base

of Q592B. The

positive-going signal causes Q592B

to

turn

on,

pulling down the

collector voltage of Q592B

and Q594. The negative-going

voltage at the collector

of

Q592B

is applied through

current-limiting diode

CR581,

to

the

base

of Q582

to

charge the holdoff

capacitor.

Sweep Stop Comparator.

The Sweep Stop

Comparator

is

used to terminate

the

sawtooth sweep when

the sweep

has

reached a pre-determined level. The circuit

components

are

chosen to set

the reference

level for sweep termination

at

approximately 10.5 volts

at the base of Q408.

The

positive-going sawtooth applied

to the base of Q408

in-

creases the current

through

R408-R409. The

base of

Q406,

which is tied to the

junction

of

R408-R409, rises

an

amount corresponding to the

sawtooth amplitude at the

base of Q408. This action

continues until the emitter

of

Q406 becomes positive

enough to forward bias

CR406.

When CR406 turns on, the

positive rise at the base of

Q436

switches the reset multivibrator.

The voltage at

the collec-

tor of

Q436 goes negative and this

negative-going

step

applied

to the sweep gate circuit

ends the sweep.

Holdoff Capacitor

and Amplifier.

Q582,

which is turned

on during

sweep time, charges

the holdoff

capacitor. When

the sweep

ends, Q582 turns off.

Now

the holdoff

capacitor

starts

to discharge toward

—50

volts

through R582,

and at

some

sweep speeds,

through R580.

When the

top of C580

discharges

negative

enough

to forward-bias

CR574 and

CR575,

holdoff

capacitor voltage

is applied

to the

base

of

Q554.

This drives Q554

to cutoff,

switching

the holdoff

multivibrator

to end holdoff

time.

Voltage limiting

diodes

CR580 and CR582

protect

the

base-emitter junction

of

Q582.

CR581 limits

the

"on" base current

of Q582.

VR576

and CR576 limit

the negative

voltage

on the hold-

off

capacitor,

C580.

The HF

STAB control, R

146B, through R583

varies the

discharge

rate of the holdoff

capacitor

to provide

a stable

display at fast

sweep rates. This

change in holdoff

allows

sweep

synchronization for

less display

jitter

at the faster

sweep

rates. The HF STAB

circuit

has little effect at

slow

sweep rates.

Sweep Holdoff Multivibrator, Q554-Q564

are con-

nected in

a

bistable Schmitt

Trigger configuration.

Quies-

cently Q554

is

off

and Q564 is

on. A positive pulse from

the

sweep reset multivibrator

switches the holdoff

multi-

vibrator

to its second stable

state, Q554

on and Q564 off.

The

sweep holdoff multivibrator

is

returned to its first

stable state

when the holdoff

capacitor has

charged negative

enough to drive Q554

to cutoff.

The fast

switching

action

of the sweep

holdoff

multivibrator

produces

sharp leading

and

trailing

edges for the

sweep holdoff

gate. The output

of

the

multivibrator,

coupled

through

emitter-follower

Q566,

goes to

the indicator

oscilloscope

and to the holdoff

discon-

nect diode.

During

sweep time the

voltage

on

the holdoff

capacitor

reverse-biases

CR575

and the

current

in

R573

switches

to

CR572,

turning

off

Q468.

VR573

determines

the time

when

the

current

switch

takes

place.

During

holdoff

time

the

holdoff

disconnect

diode,

CR571,

controls

the current

available

to

the reset

control

amplifier,

Q468.

The

positive-

going

edge

of the

holdoff

gate turns

CR571

on.

This

moves

the

emitter

of

Q468 positive,

turning

it

off.

At the

end of

holdoff

time,

the

negative-going

edge

of the

holdoff

gate

opens

CR571,

making

the

current

through

R468

available

to the

reset

control

amplifier.

Reset

Control Amplifier.

Q468 provides

current to

the

base

of Q436

to switch the

sweep reset

multivibrator

to its

reset

state.

The current through

R468 into

the emitter of

Q468 is

controlled

by

CR571

and

CR572

as stated

above,

or

by CR468

as explained

under

single-sweep

operation.

Sweep

Reset Multivibrator.

The sweep

reset multivi-

brator, Q432-Q436,

resets

the sweep

gate TD

at the end of

holdoff

time. In

the reset state,

Q432

is off and Q436

is

conducting.

The top of R438

is pulled

up to its high

level.

The

sweep is

terminated by

current from

Q406 moving

the

base of

Q436

positive

to cutoff.

This

switches the multivi-

brator to

its other stable

state, Q432

on

and Q436 off.

The

voltage

at the

top of R438

drops negative

to its low

level.

This

negative

step is applied

to the

sweep gate

stage to latch

the sweep

gate TD in its

low-voltage

state.

At

the end of holdoff

time Q468

is turned

on, driving

the

base of Q436 less

positive.

This turns

Q436 on

and the

multivibrator

switches

back to its

reset state.

The voltage

at

3-7

Circuit

Description-7B71

(SN

B205000

and

Up)

the top of

R438 is pulled

up to its

high level.

This

positive-

going step

is applied to the

Sweep

Gate Stage

to unlatch

the

Sweep Gate

TD and the

sweep circuits

are

ready for

the

next sweep

to start.

Single

Sweep

Operation

General. Operation

of the

Sweep

Generator

Circuit

in

the

SINGLE SWEEP

position

of the

TR

IGGER

I NG MODE

switch is similar

to

operation in

the

other

modes.

However,

after

one

sweep has

been

produced,

the

Sweep Reset

Multi-

vibrator

Stage

does not

reset. All

succeeding

trigger

pulses

are

locked

out until

the

RESET

button

is

pressed.

In

the

SINGLE

SWEEP

position

of

the

MODE

switch,

-15

volts

is removed

from

the

top of

R464.

CR466

is

opened

and

CR468

becomes

forward-biased,

opening

a

current

path

through

R468-CR468-R466.

Now,

at

the end

of

holdoff,

there

is no

current

through

0468

to pull

down

the

base

of 0436

and

the

Sweep

Reset

Multivibrator

does

not

reset.

The

circuit

remains

in

this

condition

until

reset

by

the

Single

Sweep

Reset

Amplifier

Stage.

Single

Sweep

Reset

Amplifier.

The

Single

Sweep

Reset

Amplifier

produces

a

negative

pulse

to

reset the

Sweep

Reset

Multivibrator

stage

so another

sweep

can be

produced

in the

SINGLE SWEEP

mode

of

operation.

Quiescently,

0454

is

conducting

hard

and 0456

is

held

cut off.

When

the RESET

button

is pressed,

CR451

is

turned

on.

This clamps

the

junction

of

CR451-CR453

at

-to.

6 volt.

CR453

and CR454

open

and

the

base of 0454

drops

to zero volts,

turning

it off.

This

turns 0456

on hard,

pulling

down

its collector

voltage.

This

negative-going

step

applied

to C457-CR459

produces

a negative

pulse

at the

base of

0436

which is

sufficient

to reset

the

sweep

reset

multivibrator.

This

enables the

sweep

gate

TD,

and the

next

trigger

pulse

will

produce

another

sweep

on

the display.

C456

provides

positive

feedback

with

a

long

time-constant

to keep

0454

off long

enough

to

prevent

switching

trans-

ients

from

producing

multiple

sweeps.

Lamp Driver.

In the SINGLE

SWEEP

MODE, the

base

of

0446 is connected

through

CR446, CR448

and CR449

to the collector

of 0436.

When 0436

is cut off,

during

holdoff

time and

until the RESET

button

is pressed, the

base of 0446

is biased to

cutoff. When

the RESET

button

is

pressed, 0436

is turned

on and its

collector

voltage rises.

This

positive-going voltage

allows 0446

to turn on

(C446

controls

turn-on time). 0446

collector

voltage drops

and

the

READY

lamp

turns on. The READY

lamp

remains

on

until

the end of the

sweep, when

0436 is

again turned

off.

Alternate

Operation

In

alternate

operation,

the indicator

oscilloscope

pro-

vides

a

sweep inhibit

current

to the

emitter

of

0410. 0410

provides

a

low

impedance

input

and a voltage

drive for the

inhibit

comparator,

0416 and

0424.

A sweep

inhibit

current

input

of 1

mA or greater

turns

0410

on. This raises

the

base

voltage of

0416,

turning

it on

and turning

0424

off.

The collector

current

of

0416

pulls

the

base of 0432

in

a

negative direction,

turning

0432

on

and 0436

off to

latch

the

sweep gate

TD as

described

previously.

Delayed

Sweep Operation

The

7B71 can be used in the

right

horizontal

(B) com-

partment of

the indicator

oscilloscope

as

a

delayed

sweep

time-base.

In this position the

delay

pickoff circuit

and the

B DELAY MODE switch

will be

inoperative.

In this

mode of operation

the

time-base in

the left

hori-

zontal

(A) compartment

provides

the

sweep

inhibit

current

to

the emitter of 0410.

The

sweep

inhibit

circuit

operates

as described

under

Alternate

Operation.

The

A time-base

also provides

a

delay

mode

control

voltage

to the anodes

of

CR462

in

the sweep

generator

and

CR357

in the

trigger

generator.

The delay mode

control

voltage

causes CR462

to

con-

duct, CR463 to turn off,

CR464

to

conduct and

CR466

to

turn

off. This

puts the B sweep

in

single sweep

mode

as

described

under Single

Sweep Operation.

During sweep

inhibit

time 0424

is

turned off.

This

turns

off

CR428, and

with CR463

off,

the

current from

R428

turns on

CR469,

C469 now

charges

to

about

-t-1.5

volts,

turning

on 0468.

This does

not

reset the

sweep,

which

is

locked

out

by the conduction

of

0416.

When

sweep inhibit ends,

0416

turns off,

making the

base of 0432

more positive. 0424

turns

on to

open CR469.

C469

hold

its charge long

enough

to allow 0468

to reset

the sweep at the

end

of

inhibit

time.

This action allows

only

one sweep

following

each time

the sweep

is inhibited.

The delay

mode control

voltage is also

connected to the

sweep

gate TD, VR358,

through

CR357 and R356.

With

the

A time-base

B

DELAY

MODE

in B TRIGGERABLE

AFTER

DELAY,

the control

voltage is about

-t-3

volts,

which does

not cause CR357 to

conduct and

the sweep will

wait for the first trigger

after the delay

interval

to

run.

With

the A time-base

B DELAY MODE

in

B

STARTS AFTER

DELAY

the control voltage

is about

-+-4.5

volts. This is

sufficient

to cause CR357

to conduct

and increase the

cur-

rent

through R356

to

the

sweep gate

TD, VR358. Now the

TD will

change to its high level

state

and start the sweep

as

soon

as it is enabled

by

the

sweep reset multivibrator

at the

end of

inhibit

current to

0410.

When

the

INDEPENDENT

mode

is selected by the A

Plug-in

DELAY MODE switch,

the sweep inhibit

is held at

3-8

a

Circuit Description—

7B71

(SN

B205000

and Up)

about the

0 mA

level.

The delay

mode

control voltage

is

clamped to ground.

The A

time-base

has no

control over

the B time-base

and each

operates

as an

independent

Time-

Base.

Delay Pickoff

Delay Comparator.

The Delay Comparator

stage allows

selection

of the amount of delay

from the

start of the

A

Sweep before

the B Sweep

Generator is turned

on.

This

stage allows

the start

of the

B Sweep

to be delayed

from

0

to 10

times

the Time-Base

A TIME/DIV

setting

after the

A

Sweep starts.

Then,

the

B Sweep

Generator

is

turned

on

and

operated

at

a sweep rate

determined

by

the B

TIME/

DIV

switch

setting.

Q520A and

Q520B operate

as a voltage

comparator.

The

FET

with the

most positive

gate controls

conduction.

Reference

voltage for

the

comparator is

supplied

by the

DELAY

TIME

MULTIPLIER,

R505,

a front-panel

control.

Delay

Stop R500 is

provided for

calibration

of the

Delay

Pickoff

circuit.

R501-C501

filter

out the

power supply

ripple

to provide

stability.

This

instrument

is calibrated

so

that the

major dial

markings

of the

DTM

correspond

to

a

major

division of

the A

Sweep

horizontal

display. For

example,

if

the

DELAY

TIME

MULTIPLIER

is

set

to

5.00,

the B

Sweep Generator

is

delayed

five

divisions of

the A

Sweep time before

it

can produce

a sweep.

Quiescently,

with

the DELAY

MODE

switch

set to a

delay

mode,

Q520A having

the

most

positive

gate is

con-

trolling

the Delay Pickoff

circuit.

The output

at

the emitter

of Q496

is at about

-t3.6

volts,

which inhibits

the

B sweep.

The sawtooth

output

signal

is applied

to

the gate of

Q520B.

When

the

sawtooth

voltage

rises

above the level

at

the gate

of

Q520A

(established

by the

DTM)

Q520B

takes over

con-

trol

of

the

comparator

current.

The

increased

current

through

Q520B makes

the

base of

Q510B less

positive.

Q510B

turns on

and the

current

through

R485 gives

a

positive-going

signal on

the

base of

Q492. Q482-Q492

is

a

fast

switching

circuit.

The

positive-going

signal

at the

base

of Q492

increases

current

through

R489

and the

emitter

of

Q482

moves

in

a positive

direction.

This decreases

the

con-

duction

of

Q482

and its

collector

voltage

rises. This

makes

the

base of

Q492

more

positive,

reinforcing

the

original

signal.

The result

of

this

regenerative

action

is very fast

switching

of this

circuit.

The

negative-going

step at the

collector of

Q492 is

applied

to the base

of Delay

Gate Emitter-Follower

Q496.

The

negative-going

step at

the emitter of

Q496 is

sent to

the Indicator

Oscilloscope

as the Delay

Gate. At the

end of

the sweep

the Delay Pickoff

circuit

reverts

to its quiescent

state to

produce

the positive-going

step at the

end of the

Delay

Gate. Q472

aids in

quickly

returning

the Delay

Switching

Amplifier

to its

quiescent

state.

Q472 is held

cut

off

by the

sweep start

gate during

sweep

time. At

the end

of

sweep time

Q472

turns

on, applying

a positive-going

signal

to

the base of Q482.

When the DELAY

MODE

switch

is in

INDEPENDENT

the base of

0492

is clamped

at

about 0 volts.

This turns

it

on hard

and the Delay

Gate output

is

held

to its

low-level.

Horizontal

Preamp

Operational

Amplifier,

U752,

provides

horizontal

posi-

tioning

control

current

to

0784,

one

side of

paraphase

amplifier 0784-0794.

Current

is determined

by settings of

horizontal POSITION

controls R774A

and

R774B.

A

positive-going

sawtooth

from

0534

drives the

base of

0794, the other

side of

the

paraphase

amplifier. This

produces

a push-pull

sawtooth

signal

at

terminals CF

and

CE

to

drive the

oscilloscope

main-frame.

X10 magnification

is

provided

when relay K780

is switched

on,

K780

shunts

0784-0794

emitter-to-emitter

resistance

with an

adjustable

resistance (R785)

which

allows

a calibrated

gain of 10.

Additional

RC

networks

in the

MAG

position

correct

for

thermal

time

constants.

Magnifier

Registration

control

R795

balances the

output

to eliminate

trace

shift when

switching

from

XI

to XI

0 magnification.

Readout

Block

The

Readout

Block

consists

of

switching

resistors

and

a

set of

contacts

operated

by

the

X10 MAG

switch. The

switching

resistors,

selected

by the

setting

of the

Readout

Switch

(part of

the TIME/DIV

switch),

are

used

to signal

the

Indicator

Oscilloscope

of the

setting

of the TIME/DIV

switch.

Refer

to

Schematic

Diagram

7,

Timing

Switch,

at

the

rear

of

the

manual to

find

the

resistors

associated

with

a

particular

setting

of

theTIME/DIV

switch.

The

number

1, 2,

or 5 is

selected

by resistors

R704-R705-R706.

The

number

of

zeros

is

selected

by

resistors

R71

1-R712-R713-R715.

The

TIME

subunit

(milli,

micro,

or

nano)

is

selected

by

resistors

R721-R722-R723-R724.

R728-R729

selects

the

symbol

S

(seconds).

R701-R702

select

the

symbol

>

(great-

er

than)

when

the

VAR

TIME/DIV

knob

is in

the

out

(uncal)

position.

R715

is

switched

out

by

the X10

MAG

to

increase

the

displayed

readout

by

a factor

of

10.

3-9

SECTION 4

MAINTENANCE

7B71 (SN B205000and Up)

Change

information,

if

any, affecting

this section

will be

found at the rear

of the

manual.

Introduction

This section of

the manual

contains

maintenance

infor-

mation

for use in

preventive maintenance,

corrective

main-

tenance and troubleshooting

of

the

7B71

.

PREVENTIVE

MAINTENANCE

General

Preventive

maintenance

consists

of cleaning,

visual

inspection,

lubrication,

etc. Preventive

maintenance

per-

formed

on a regular

basis may

prevent

instrument

break-

down

and

will

improve the

reliability

of

this

instrument.

The severity of

the

environment

to

which the

7B71

is

subjected

determines the

frequency

of

maintenance.

A

con-

venient time

to perform

preventive

maintenance

is pre-

ceding

recalibration of

the

instrument.

Cleaning

The

7B71

should be cleaned

as often as

operating

condi-

tions require.

Accumulation

of

dirt

in the

instrument

can

cause

overheating

and component

breakdown.

Dirt

on

com-

ponents

acts as an insulating

blanket

and prevents

efficient

heat

dissipation.

It may also

provide

an electrical

conduc-

tion

path.

The covers

of

the indicator

oscilloscope

minimize

the

amount of dust which

reaches the

interior of

the

7B71.

Operation of

the system

without the

indicator

oscilloscope

covers

in place necessitates

more frequent

cleaning.

When

the

7B71 is not in

use, it should

be stored

in

a

protected

location

such as a

dust-tight

cabinet.

\

^

CAUTION

<

<,

Avoid the use

of

chemical

cleaning

agents which

might

damage the plastics

used in this

instrument.

Avoid chemicals

which contain

benzene, toluene,

xylene, acetone or similar

solvents.

Exterior.

Loose

dust accumulated

on the outside

of the

7B71

can

be removed

with a soft

cloth or small

paint brush.

The paint brush

is particularly

useful for dislodging

dirt

on

and

around

the front-panel

controls.

Dirt which remains

can

be

removed with

a

soft

cloth dampened

in a mild

detergent

and

water

solution.

Abrasive cleaners

should not

be used.

Interior. Dust

in

the

interior of the

instrument

should

be removed

occasionally due

to its electrical

conductivity

under high-humidity conditions.

The

best way

to

clean

the

interior

is to blow

off

the

accumulated

dust with dry,

low-

velocity air. Remove

any dirt

which remains

with

a

soft

paint

brush or a cloth

dampened

with a mild detergent

and

water solution.

A cotton-tipped

applicator

is useful for

cleaning

in narrow spaces.

Visual

Inspection

The 7B71

should be

inspected

occasionally for

such

defects

as broken

connections,

broken

or damaged

circuit

boards, improperly

seated

transistors

or relay,

and

heat-

damaged

parts.

The corrective procedure

for

most

visible defects

is

obvious; however, particular

care

must

be taken if

heat-

damaged components are

found.

Overheating

usually indi-

cates other trouble

in the

instrument;

therefore,

it is

important that

the cause of

overheating

be corrected

to

prevent

a

recurrence of

the

damage.

Transistor

and

Integrated

Circuit

Checks

Periodic

checks of

the

transistors

and

integrated

circuits

in the 7B71

are not

recommended.

The

best check

of

transistor

and

integrated

circuit

performance

is actual

operation in

the instrument.

More

details are

given

under

Troubleshooting.

Recalibration

To ensure

accurate

measurements,

check

the

calibration

of this

instrument

after

each

1000

hours

of

operation

or

every

six

months

if

used

infrequently.

In addition,

replace-

ment of

components

may

necessitate

recalibration

of

the

affected

circuits.

Complete

calibration

instructions

are

given

in

Section

5.

The

Performance

Check/Calibration

Procedure

can also

be

helpful in

localizing

certain

troubles

in the

instrument.

In

some cases,

minor

troubles

may be

revealed

and/or

cor-

rected

by calibration.

4-1

Maintenance—

7B71

(SIM B205000

and Up)

TROUBLESHOOTING

Introduction

The following

information

is provided

to

facilitate

troubleshooting of

the 7B71. Information

contained

in

other sections of

this manual should

be used along

with the

following information

to aid in locating

the defective

com-

ponent. An understanding of

the circuit

operation

is very

helpful

in locating

troubles. See the

Circuit

Description

section for complete

information.

Troubleshooting

Aids

Diagrams.

Circuit diagrams are

given on foldout

pages in

the Diagram Section. The

component

number and

electrical

value of each

component in this

instrument are

shown

on

the diagrams.

Important

voltages

and waveforms

are also

shown on the diagrams.

Switch

Cam

Identification.

Switch

cam

numbers

shown

on the

diagrams

indicate

the

position

of

the

cam in

the

complete

switch assembly.

The

cams are

numbered

from

the

front, or

mounting

end of

the

switch,

toward

the

rear.

Resistor

Color-Code.

In

addition

to

the brown

composi-

tion resistors,

some

metal-film

resistors

and some

wire-

wound

resistors

are used

in

the

7B71

. The

resistance

values

of

wire-wound

resistors

are

printed

on

the

body of

the

component.

The resistance

values

of

composition

resistors

and metal-film

resistors

are

color

-coded

on the

components

(some

metal-film

resistors

may

have

the

value

printed

on

the

body) with EIA

color

code.

The

color

code

is read

starting

with

the

stripe nearest

the end of

the

resistor.

Composition

resistors

have four

stripes

which

consist of

two significant

figures,

a multiplier

and

a

tolerance

value

(see Fig. 4-1).

Metal-film

resistors

have

five

stripes

con-

sisting

of three

significant

figures,

a multiplier

and a toler-

ance value.

Capacitor

Marking.

The

capacitance

values of

common

disc

capacitors and

small

electrolytics

are

marked

in micro-

farads

on the

side of

the

component

body. The

white

ceramic

capacitors

used in

the

7B71

are color

coded

in

picofarads

using

a modified EIA

code (see Fig. 4-1).

Diode

Color

Code.

The

cathode

end of

each

glass-

encased

diode is

indicated

by a stripe,

a

series

of stripes or

a

dot. For

most

silicon or

germanium

diodes

with

a series of

stripes,

the

color code

also

indicates

the type

of diode

or

identifies the

Tektronix

Part

Number

using

the resistor

color code

system (e.g.,

a

diode

color-coded

blue- or

pink-

brown-gray-green

indicates

Tektronix

Part Number

152-0185-00).

The

cathode

and

anode

ends of

metal-

encased

diodes

can be identified

by the

diode

symbol

marked

on the

body.

Troubleshooting

Equipment

The

following

equipment

is

useful

for

troubleshooting

the7B71:

1.

Transistor

Tester

Description:

Tektronix

Type

576

Transistor-Curve

Tracer

or

equivalent.

Purpose:

To test

the

simiconductors

used in

this

instrument.

2.

Volt-ohmmeter

Description:

20,000

ohms/volt. 0-500

volts

DC.

Accurate

within

3%.

Test probes

must

be well

insulated.

Purpose:

To measure

voltages

and resistances.

3.

Test

Oscilloscope

Description:

DC to 200

MFIz

frequency

response,

5

millivolts

to 5 volts/division

deflection factor.

Use a

10X

probe.

Purpose:

To check

waveforms

in the

instrument.

4.

Plug-In

Extender

Description:

Rigid plug-in

extender,

Tektronix

Part

number 067-0589-00.

Purpose:

Permits

operation

of the

unit outside

the

plug-in

compartment

for

better

accessibility

during

troubleshooting.

Troubleshooting

Techniques

This

troubleshooting

procedure

is arranged in

an order

which

checks the simple

trouble

possibilities before

pro-

ceeding

with extensive

troubleshooting.

The first few

checks

ensure proper

connection,

operation

and calibration.

If

the trouble

is

not located

by these checks,

the remaining

steps aid

in locating the

defective

component.

When

the

defective

component

is located,

it should be

replaced fol-

lowing

the replacement

procedures

given

under Corrective

Maintenance.

1.

Check

Control

Settings.

Incorrect

control settings

can indicate

a

trouble

that

does not

exist.

If

there

is any

question

about the

correct

function

or operation of

any

control, see the

Operating

Instructions

section.

4-2

Maintenance-7B71

(SN

B205000 and Up)

2.

Check

Associated

Equipment.

Before

proceeding

with

troubleshooting

of the

7B71,

check

that the

equip-

ment

used with this

instrument

is

operating

correctly.

Check

that the signal

is properly

connected

and that

the

probe cable

is not defective.

The indicator

oscilloscope

and

vertical

plug-in

unit can

be checked for

proper

operation

by

substituting

another

time-base

unit

which

is known

to

be

operating properly

(perferably

another

7B71 or similar

unit). If

the trouble

persists after

substitution,

the

indicator

oscilloscope

and/or vertical

plug-in

unit

is defective.

3.

Check

Instrument

Calibration.

Check

the

calibration

of

this instrument,

or the

affected

circuit if

the

trouble

exists in

one circuit.

The

apparent

trouble

may only

be

a

result

of

misadjustment

and

may be

corrected

by calibra-

tion. Complete

calibration

instructions

are

given

in the

Calibration

section.

4.

Visual Check.

Visually

check

the

portion of

the

instrument in

which the

trouble

is located.

Many

troubles

can

be located

by visual

indications

such as

unsoldered

connections,

broken wires,

damaged

components,

etc.

5.

Isolate

Trouble to

a Circuit.

To isolate

a trouble

to a

circuit,

note the

trouble

symptom.

The

symptom

often

indicates

the circuit

in which

the

trouble

is

located.

For

example, if

normal

triggering

can

be

obtained

in

the I NT

mode

but cannot

be

obtained

in

the EXT

mode,

the

external

trigger

amplifier

or the

SOURCE

switch

is prob-

ably

at

fault.

When

trouble

symptoms

appear,

use the

front-

panel controls

and the

CRT

display

to try

to isolate

the

trouble

to one circuit.

When the

trouble

appears

in

more

than

one circuit,

check all

affected

circuits

by taking

volt-

age and

waveform

readings.

Fig.

4-2

provides

a guide

to aid in

locating

a defective

circuit.

This chart

does

not include

checks for

all

possible

defects;

use steps

6 and 7 for

further

troubleshooting.

Start

from

the top of

the chart

and

perform

the

given checks

on

the left

side of the

page

until a step

is found

which

is

not

correct.

Further

checks

and/or

the

circuit

in which

the

trouble is

probably located

are

listed

to the

right of

this

step.

After

the defective

circuit

has

been

located,

proceed

with

steps

6

and

7 to locate

the

defective

component(s).

Composition

Resistors:

Metal-Film

Resistors

Ceramic Capacitors:

©0

“"d

©

—

1st, 2nd

and 3rd significant

figures;

0

—multiplier;

—tolerance;

©

—temperature

coefficient.

Signifi-

Multiplier

j

Tolerance

Color

cant

Figures

Resis-

tors

Capaci-

tors

Resis-

tors

Capaci-

tors

Silver

...

1

0-2

...

±10%

—

Gold

...

lO-’-

±5%

—

Black

0

1

1

±20%

or

2pF*

Brown

I

10

10

±1% ±

1

%

or

0.1

pF*

Red

2

102

102

±2%

±2%

Orange

3

102

10“

±3%

±3%

Yellow

4

10^

10‘

±4%

+

100%

-0%

Green

5

10=

10“

±0.5%

±5%

or

0.5

pF’^

Blue

6

10“

10“

—

Violet

7

—

—

Gray

8

10-2

+80%

-20%

or

0.25

pF*

White

9

10-^

—

±10%

or

1

pF*

(none)

i

-

-

.

-

±20%

±10%

or

1

pF*

NOTE:

and/or

color

code for

capacitors

depends

upon

manufacturer

and

capacitor^jype^^

be

present

in some

cases.

Fig.

4-1

.

Color-code for resistors and ceramic

capacitors.

Maintenance—7B71 (SISl

B205000 and

Up)

Fig.

4-2.

Troubleshooting

chart for

the

7B71.

lAl

4-4

Maintenance—

7

B71

(SIM

B205000 and

Up)

For

a trouble

not

covered

by this

chart,

use

the

troubleshooting

methods

in

steps

6 and

7 of

the

troubleshooting

techniques.

Fig.

4-2.

T

roubleshooting

chart

for

the

7B71

.

Maintenance-7B71

(SN

B205000

and Up)

6.

Check

Voltages

and

Waveforms.

Often

the

defective

components

can

be located

by checking

for

the

correct

voltage

or

waveform

in the

circuit.

Typical

voltages

and

waveforms

are given

on the

diagrams.

^ CAUTION

<

Do

not

damp

probe

to pin

connectors

as this may

break or

damage

the

connectors.

NOTE

Voltages

and

waveforms

given

on the diagrams

are

not

absolute and

may

vary

slightly

between

instru-

ments.

To

obtain

operating

conditions

similar

to

those

used

to take

these

readings,

see the first

diagram

page.

7.

Check

Individual

Components.

The

following

pro-

cedures

describe

methods of

checking

individual

com-

ponents

in the

7B71

. Components

which

are

soldered

in

place

are

best checked

by

disconnecting

one end.

This

isolates

the

measurement

from

the

effects

of

surrounding

circuitry.

A.

RELAYS.

The 7B71

uses

two

types of

relays.

The

eight

pin DPDT

relay is

symmetrical

and may be

replaced

in

its socket

facing either

direction.

The five

pin

SPOT relay

will mate

with its

socket

in one

direction

only.

These

relays,

which are

plugged

into the

circuit

board,

may

be

removed

and checked.

Using

an

ohmmeter,

check for

a

DC

resistance of

600 ohms

across

the

coil. Each

relay

can

be

actuated

by applying

15 volts

across

the

coil. With the

relay

actuated,

check the

normally

open

contacts for

continuity.

When

returning

the relays

to the

circuit

board,

place

the

five

pin relay

in the five

pin

socket and

the eight

pin

relays

in

the

eight

pin

sockets.

B. TRANSISTORS

and INTEGRATED

Cl RCUITS. The

best check of transistor

and integrated

circuit opera-

tion is actual

performance

under operating

conditions. If

a

transistor or

integrated circuit

is

suspected of being

defective,

it

can best be checked

by substituting

a new

component or

one which

has been

checked

previously.

However,

be

sure that circuit

conditions are

not such that

a

replacement

transistor

might also

be damaged. If

substitute

transistors

are not available,

use

a dynamic tester

(such as

Tektronix

Type

576).

C.

DIODES. A diode

can be checked

for an open

or

for

a

short

circuit

by

measuring

the

resistance

between termi-

nals with an

ohmmeter set

to

the

R

X Ik scale. The diode

resistance

should be very high in

one direction

and very low

when the meter

leads are reversed.

Do not check tunnel

diodes or

back diodes with an ohmmeter.

>

CAUTION

^

Do not

use an ohmmeter

scale that

has

a high

internal

current.

High

currents

may

damage the

diode.

D. RESISTORS.

Resistors

can

be checked

with an

ohmmeter.

Check the

Electrical Parts

List for

the tolerance

of

the

resistors

used in this instrument.

E.

INDUCTORS.

Check

for

open

inductors

by

checking

continuity with

an

ohmmeter.

Shorted

or partially

shorted

inductors

can

usually

be found

by checking

the

waveform

response

when

high-frequency

signals

are passed

through

the

circuit. Partial

shorting

often

reduces

high-

frequency

response.

F.

CAPACITORS.

-A

leaky

or shorted

capacitor

can

best be

detected

by checking

the

resistance

with

an ohm-

meter

on the highest

scale.

Do not

exceed

the

voltage rating

of

the

capacitor.

The resistance

reading

should

be high after

initial

charge

of the

capacitor.

An

open

capacitor

can

best

be detected

with

a

capacitance

meter

or

by checking

whether

the

capacitor

passes

AC

signals.

8.

Repair

and Readjust

the Circuit.

If

any defective

parts

are

located, follow

the

replacement

procedures given

in this

section.

Be sure

to check

the

performance

of

any

circuit that has

been repaired

or that

has had any

electrical

components

replaced.

CORRECTIVE

MAINTENANCE

General

Corrective maintenance

consists of

component replace-

ment

and instrument repair.

Special

techniques

required

to

replace

components

in

this

instrument

are given here.

Obtaining

Replacement

Parts

Standard

Parts.

All electrical

and mechanical

part

replacements

for the 7B71

can

be

obtained through

your

local

Tektronix Field

Office

or

representative.

How-

ever,

many of

the standard

electronic

components

can be

obtained

locally

in less time

than

is

required

to order

them

from

Tektronix,

Inc. Before

purchasing

or ordering

replace-

ment

parts,

check

the parts

list for

value,

tolerance,

rating

and

description.

NOTE

When

selecting

replacement

parts, it

is important

to

remember

that the

physical

size and

shape of

a com-

ponent may affect

the

performance

in

the instru-

ment,

particularly

at high

frequencies.

AH

replace-

ment

parts should

be direct

replacements

unless it

is

known

that

a

different

component

will not

adversely

affect

instrument

performance.

4-6

REV.

B, MAR. 1975

Maintenance—

7B71 (SN

B205000 and Up)

Special

Parts.

In

addition

to the

standard

electronic

components,

some

special

parts are

used

in the

7B71

. These

parts

are

manufactured

or

selected

by

Tektronix,

Inc.

to

meet

specific

performance

requirements,

or

are

manu-

factured for

Tektronix

Inc. in

accordance

with

our

specifi-

cations.

These

special

parts

are

indicated

in the

parts

list

by

an asterisk

preceding

the

part

number.

Most

of

the

mechanical

parts

used in this

instrument

have

been

manu-

factured

by Tektronix,

Inc. Order

all

special

parts

directly

from

your local

Tektronix

Field

Office

or

representative.

Ordering

Parts.

When

ordering

replacement

parts

from

Tektronix,

Inc.,

include

the following

information:

1.

Instrument

Type.

2.

Instrument

Serial

Number.

3.

A description

of

the part

(if

electrical,

include

circuit

number).

4.

Tektronix

Part

Number.

Soldering

Techniques

Disconnect

the

instrument from

the

power source

be-

fore

soidering.

Circuit

Boards.

The

components

mounted

on the

circuit

boards

in the amplifier

can

be replaced

using

normal

circuit

board

soldering

techniques.

Keep

the

following

points in

mind

when

soldering

on the

circuit

boards.

1

.

Use a pencil-type

soldering

iron

with

a power

rating

from

1 5 to

50 watts.

2.

Apply

heat

from

the

soldering

iron

to

the

junction

between

the

component

and

the

circuit

board.

3.

Heat-shunt

the lead

of

the

component

by means

of

a

pair of

long-nosed

pliers.

4.

Avoid

excessive

heating

of

the

junction

with

the cir-

cuit

board,

as

this could

separate

the

circuit

board

wiring

from

the

laminate.

5.

Use electronic

grade

60-40

tin-lead

solder.

6.

Clip

off

any

excess lead

length

extending

beyond

the

circuit

board

and

clean off

any residual

flux

with

a flux-

removing

solvent.

Be careful

that

the

solvent

does

not

re-

move

any printing

from

the

circuit

board.

Metal

Terminals.

When

soldering

metal

terminals

(e.g.,

switch

terminals,

potentiometers,

etc.),

use

60-40

tin-lead

solder

and

a 15 to

50 watt

soldering

iron.

Observe

the

following

precautions

when

soldering

metal

terminals:

1. Apply

only

enough

heat

to

make

the solder

flow

freely.

2.

Apply

only enough

solder

to form

a solid

connection.

Excess

solder

may impair

the

function of

the part.

3. If

a wire extends

beyond

the solder

joint, clip off the

excess.

4. Clean

the

flux

from

the

solder joint

with

a

flux-

removing solvent.

Component

Replacement

WARNING^

Disconnect

the

equipment

from

the

power

source

before

replacing

components.

Relay

Replacement.

The relays

in

the

7B71 are

manu-

factured

by

Tektronix

Inc. If

a relay

fails,

a

replacement

may

be ordered

from

your

local

Tektronix

Field

Office

or

Representative.

The

five

pin

relay

sockets

on the

circuit

board

will

accept

only

the five

pin

SPOT

relay.

It

is

pos-

sible,

however,

to place

a five

pin

SPOT relay

in an

eight

pin

socket

intended

for

use

with

one of

the

eight

pin

relays.

This

would

not

damage

the

instrument

or

the relay,

but

would

cause a

malfunction

of

the

instrument.

The

eight

pin

DPDT

relays

may

be

placed

in

their

sockets

facing

either

direction,

as

these relays

are

symmetrical.

CAUTION

(

K

-/^ y-

jr-

The

relays

used

in this

instrument

can be

damaged

by

heat.

Do

not apply

a soldering

iron

to

the

relay

socket

until the

relay

has

been

removed

from

the

socket.

Transistor

and

Integrated

Circuit

Replacement.

Transis-

tors and

integrated

circuits

should

not

be

replaced

unless

actually

defective.

If

removed

from

their

sockets

during

routine

maintenance,

return

them

to

their

original

sockets.

Unnecessary

replacement

of

transistors

may effect

the cali-

bration

of

this

instrument.

When

transistors

and

integrated

4-7

IV!aintenance-7B71

(SN B205000 and

Up)

Fig. 4-3.

Electrode configuration

of

transistors and integrated

cir-

cuits

used in

this instrument.

circuits

are

replaced,

check

the

operation of

that part of

the

instrument

which

may

be affected.

Replacement

transistors

and

integrated

circuits

should

be

of

the

original

type or

a direct

replacement.

Remount

the

transistors

and

integrated

circuits

in the

same

manner

as

the original.

Fig.

4-3

shows

the lead

configurations of

the

transistors

and integrated

circuits

used

in this

instrument.

This view

is

as seen from the

bottom

of

the transistor

and

integrated

circuit.

When

replacing

transistors,

check the

manufacturer's

basing diagram

for

correct

basing.

Interconnecting

Pins and Pin

Socket

Replacement.

Two

types

of

mating connectors

are

used for these

interconnec-

ting

pins.

If

the mating

connector is

mounted on

a plug-on

circuit

board,

a

special

socket is

soldered

into the board. If

the

mating connector is

on the end of

a lead,

a

pin

connec-

tor is

used to mate with the

interconnecting

pin.

The

fol-

lowing

information

provides the

replacement

procedure for

the various types of

pins and

pin sockets.

" '

" ' ' '

''

CAUTION

^

'

V

When rennoving the

stub

of

a broken pin connector,

it

is

important not

to

disturb

the old ferrule which

is

swagged

into the

circuit

board.

Use the minimum

amount of heat necessary

to remove

the pin. The new

pins are

supplied with ferrules

intact.

Remove

the

ferrule from

the new pin before

inserting

the

pin into

the old ferrule

in the circuit

board.

The old ferrule

may

be reamed

out with

a .031 drill

If necessary.

A circuit

board pin replacement

kit including

neces-

sary tools, instructions

and

replacement

pins

is avail-

able from

Tektronix, Inc.

Order

Tektronix Part

No.

040-0542-00.

A. CIRCUIT

BOARD

PINS.

To

replace

a pin which

is

mounted

on a circuit

board,

first

disconnect

any

pin

con-

nectors.

Unsolder

the damaged

pin and

pull it

out of

the

circuit

board.

Press

the new

pin

into

the ferrule

in

the

circuit

board.

(Notice

that

the

ferrule

is not

centered

on the

pin;

be

sure

the

replacement

pin is

positioned

in

the

same

manner

as the

original.)

Solder

the

pin on

both sides

of

the

circuit

board. If

the

pin was

bent

at an

angle

to mate

with

a

connector,

bend the new

pin

to

match

the

associated

pins.

The

inside

radious of

this

bend

should

not

be less

than

0.025

inch.

B. CIRCUIT

BOARD

PIN

SOCKETS. The

pin sockets

on the circuit

boards are soldered

to the rear of the

board.

To replace

the sockets, first

unsolder the

socket (use

a

vacuum-type

desoldering

tool

to remove excess solder).

Straighten the

tabs on the

socket to remove it from

the

hole

in the circuit board. Place

the

new socket in the circuit

board hole

and press the tabs

down against the board.

Solder

the socket tabs

to

the

circuit board.

4-8

S

Maintenance-7B71

(SN

B205000 and

Up)

NOTE

The

spring tension

of

the

terminal

sockets

ensures

a

good

connection

between

the

circuit

board

and

the

pin.

This

spring

tension

can be

destroyed

by

using the

pin

sockets

as

a connecting

point for

spring-loaded

probe

tips, alligator

dips, etc.

C.

END-LEAD PIN

CONNECTORS.

The

pin

connec-

tors

used to connect

the wires

to the circuit

board

pins

are

clamped

to the ends of

the

associated

leads.

To replace

a

damaged pin

connector, first

remove

the

old pin

connector

from

the

end

of

the lead.

Clamp

the

new pin

connector

to

the end of

the lead.

Some of

the

pin

connectors

are

grouped

together and

mounted

in a

plastic holder.

These

connectors

are

removed

and

re-installed

as

a unit.

To

provide

correct

orientation of

this

multi-connector

when

it

is

replaced,

an arrow

is stamped

on

the

circuit board

and

a

matching

arrow

is moulded

into

the plastic

housing

of

the

multi-pin

connector.

Switch Replacement.

Two

types of

switches

are

used

in

the

7B71. The

pushbutton

switches

and the

cam-type

switch

should

be replaced

as

a unit if

damaged.

The fol-

lowing

special

maintenance

information

is provided

for

the

cam-type

and

pushbutton

type

switches.

"

"

"

"

^

^

CAUTION

<.

Repair of

the cam switch

should

only be

undertaken

by skilled

maintenance

personnel.

Switch

alignment

and contact

spacing

must be carefully

maintained for

proper

operation of

the

switch. A

cam-type switch

repair

kit including

the

necessary

tools, instructions

and replacement

contacts

is available

from

Tektronix,

Inc.

Order Tektronix

Part

No.

040-0541-00.

A. CAM-TYPE

SWITCH.

The

cam-type

switch

(TIME/

DIV) consists of

a

rotating

cam,

which is

turned

by the

front

panel knob,

and

a set of

contacts

mounted

on

an

adjacent circuit

board.

These

switch

contacts

are

actuated

by lobes

on the

cam. The

TIME/DIV

switch

can

be dis-

assembled for

inspection,

cleaning,

repair

or

replacement

as

follows:

1

.

Remove

the four

screws

which

hold

the

metal cover

over the switch.

The

switch is

now

open for

inspection

or

cleaning.

2.

To completely

remove

the

switch,

loosen

the

set

screw

on the

collar securing

the

VARIABLE

shaft

to the

VARIABLE

potentiometer

and pull

the shaft

completely

out the front of

the unit.

Loosen

the two

set screws

on the

TIME/DIV

knob

and remove

the

knob.

Remove the

plastic

bushing

from

the access

hole for

the

TIME/DIV

shaft.

3.

Remove the

sweep generator

board

by loosening

the

five

securing

screws and

carefully

lifting

out.

4.

Remove

the six screws

which

hold

the cam

switch

to

the

interface circuit

board and

remove

the

cam switch.

5.

To remove

the cam from

the front

support

block,

remove

the retaining

ring from

the

shaft

on the front

of

the

switch

and slide

the cam

out

of

the

support

block.

Do not

lose the

small detent roller.

6.

To replace defective

switch

contacts,

unsolder

the

damaged

contact

and clean

the solder

from

the

hole in

the

circuit

board.

Then position

the

new

contact

in the

hole so

it is

properly aligned

with

the

other switch

contacts

and

so

it will

properly

contact the

mating

area

on the

circuit

board

when it

is actuated.

Solder

the new

contact

into

place,

being sure

that the

spring

end of

the

contact has

adequate

clearance from

the circuit

board.

7.

To re-assemble the

switch,

reverse

the above

pro-

cedure.

B. PUSH-BUTTON

SWITCHES.

Use

the following

pro-

cedure

to replace the five

pushbutton

switches:

1.

Loosen

the set

screws

and

remove

the

POSITION,

LEVEL/SLOPE,

TIME/DIV

and

VARIABLE

knobs.

2.

Remove

the front

panel

to gain

access

to the

switch

mounting

screws.

3.

To

remove

the

B

DELAY

MODE

switch,

remove

the

two

Phillips

head

screws

and

disconnect

the

multi-pin

connector.

4.

To remove

the

MAGNIFIER

switch,

remove

the

Phillips head

screw

and

disconnect

the

multi-pin

connector.

5.

To remove

the

TRIGGERING

switches,

remove

the

two

Phillips

head

screws

from

each

of the

MODE,

COUPLING

and

SOURCE

switches.

Disconnect

the fol-

lowing

multi-pin

connectors:

DELAY

TIME

MULTIPLIER,

B DELAY

MODE,

SWP

CAL,

POSITION,

LEVEL/SLOPE,

TRIG

D

and

MAGNIFIER.

Disconnect

the

pin

connectors

from

the

SOURCE

and

COUPLING

switches.

Remove

the

four

screws

securing

the front

of

the

unit

to the

top and

bottom

and

remove

the front

of

the unit.

Remove

the

TRIGGERING

switches

(the

sweep

generator

board

may

have

to be removed

to take

out

the

TRIGGERING

MODE

switch).

4-9

Maintenance-7B71

(SN

B205000

and

Up)

Light Bulb

Replacement.

To

replace

the

light

bulbs

fol-

low

the

above

procedure

to remove

the

switches.

Remove

the

screw

and

cover from

the

back

of

the switch

to expose

the

light

bulb.

Unsolder the

two leads

and remove

the light

bulb.

Cut the

leads of

the

replacement

light

bulb

to the

same

length

as those of

the

old

bulb.

Place

insulating

sleeves

over the

leads

and

replace

the new

bulb in

the

exact

posi-

tion of

the old

bulb.

Reassemble

by

reversing

the

above

procedure.

Instrument

Repackaging

If

the

7B71

is

to be

shipped

for

long

distances

by com-

mercial

means

of

transportation,

it

is

recommended

that

the

instrument

be

repackaged

in

the original

manner

for

maximum

protection.

The

original

shipping

carton

can be

saved

and

used

for

this

purpose.

Repackaging

information

and/or

new shipping

cartons

can be

obtained

from

Tek-

tronix,

Inc. Contact

your

local

Tektronix

Field

Office

or

represetnative.

NOTE

The

plug-ins

should

not

be

shipped

installed

in an

os-

cilloscope.

The

oscilloscope

packaging

material Is

not

designed

to

protect

the

plug-ins.

4-10

R'

Magnifier

f

Maintenance-7B71

(Sl\l

B205000

and Up)

P740

R530C

R530A

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Fig.

4-6.

Interface

board

(left

side)

showing

location

of

components

and

connections.

[Al

4-13

^C1

Maintenance-7B71

(SN

B205000

and Up)

Fig.

4-8.

External

board

showing

location

of

components.

7B71

(SN B205000and Up)

SECTION 5

PERFORMANCE

CHECK/CALIBRATION

Change

information,

if any,

affecting

this section

will

be found

at the rear of

the manual.

Introduction

To

assure instrument

accuracy, check

the

calibration

of

the

7B71

every

1000 hours

or

every

six

months if

used

infrequently.

Before calibration,

thoroughly

clean and

inspect this

instrument

as outlined in

the

Maintenance

Section.

The

complete Performance

Check/Calibration

Procedure

can

be

used

to check

instrument

performance

without

removing side

covers or making

internal

adjustments

by

performing

all portions except

the ADJUST

part of

the

steps. Screwdriver

adjustments

which

are accessible

without

removing

the covers

are adjusted

as part

of the

performance

check procedure. A

note titled PERFORMANCE

CHECK

ONLY

gives

instructions which

are

applicable only

to the

performance

check

procedure.

Completion of each

step in the

complete

Performance

Check/Calibration

Procedure

insures

that this

instrument

meets

the

electrical

specifications

given in

Section

1. For

best overall instrument

performance,

when

performing

a

complete

calibration procedure,

make

each

adjustment

to

the

exact setting even if the CHECK

is within

the

allowable

tolerance.

A Short-Form

Procedure

is given

prior

to

the

complete

procedure. To

facilitate

instrument

calibration for

the

experienced calibrator,

the

Short-Form

Procedure

lists

the

calibration adjustment

necessary

for each

step

and the

applicable tolerances. This

procedure

also includes

the

step

number and

title

as

listed

in the

complete

Performance

Check/Calibration

Procedure

and

the

page number

on

which

each

step begins.

Therefore,

the

Short-Form

Pro-

cedure

can be used

as

an

index

to

locate

a step in the

complete procedure.

Another

feature

of the

Short-Form

Procedure

is the

spaces provided

to record

performance

data or

to

check

off

steps

as

they

are

completed.

This

procedure may

be reproduced

and used

as a permanent

record

of instrument

calibration.

NOTE

AH

waveforms

shown in

this

procedure

were

taken

with

a Tektronix

Oscilloscope

Camera

System.

Limits, tolerances

and waveforms

in

this procedure

are

given

as

calibration

guides and should

not

be

interpreted

as

instrument

specifications

except

as

stated

in Section 1.

A

partial

calibration is

often

desirable

after

replacing

a

component

or to touch up

an

adjustment

of

a portion

of

the

instrument

between

major

recalibrations.

For

partial

calibration,

set the

controls

as given

under

Preliminary

Control Setting

and start with

the

desired

check

or

checks.

If

any

controls

need

to be changed

from

the

preliminary

settings

for this

portion

of the

calibration

procedure,

they

are

listed under

the

heading

Partial

Procedure.

To

prevent

unnecessary

recalibration

of other

parts

of the

instrument,

readjust

only if

the

tolerance

given

in the CHECK

part

of

the

step

is not

met. If

readjustment

is

necessary,

also

check

the

calibration

of

any

steps

listed

in the

INTERACTION

part of the

step.

TEST

EQUIPMENT

REQUIRED

General

The

following

test

equipment

and

accessories,

or its

equivalent,

are

required

for

complete

calibration

of

the

7B71.

Specifications

given

are the

minimum

necessary

for

accurate

calibration.

Therefore,

some

of the

recommended

equipment

may have

specifications

which

exceed

those

given.

All

test

equipment

is

assumed

to

be

correctly

calibrated

and

operating

within

the

given

specifications.

If

equipment

is

substituted,

it

must

meet

or

exceed

the

specifications

of the

recommended

equipment.

Special

Tektronix

calibration

fixtures

are

used

in this

procedure

only

where

they

facilitate

calibration.

These

special

calibration

fixtures

are

available

from

Tektronix,

Inc.

Order

by part

number

through

your

local

Tektronix

Field

Office

or

representative.

1. Test

time-base

compatible

witl]

the

Tektronix

7700-series

oscilloscope.

7B70

used

in

these

checks.

iAj

5-1

Performance

Check/Calibration—

7B71 (SN B205000 and

Up)

2.

Vertical amplifier

(2

each)

for use

with Tektronix

7000-series oscilloscopes.

Bandwidth,

200

MHz

or greater;

deflection

factor,

5

volts

to

less

than

50 millivolts.

Tektronix

7A16A

used in these

checks

(a single 7A12

may

be

used instead

of the

two

7A16A

amplifiers).

3.

Oscilloscope.

Tektronix

7700 or

7900

series.

7704

used in these

checks except

step

19

(7904).

4.

Rigid

plug-in extender. Tektronix

Part Number

067-0589-00.

5.

Low-frequency sine-wave

generator.

Frequency

range, 20

hertz

to

greater than

50 kilohertz;

output

amplitude,

150

millivolts

to 5

volts. For

example. General

Radio Model

1310-A

Oscillator.

6.

Constant amplitude sine-wave

generator. Reference

frequency,

50

kilohertz; frequency

range, 10 megahertz

to

100 megahertz; output amplitude variable from

150 milli-

volts to 5

volts. Tektronix Type

1 91 recommended.

7.

Time-mark generator.

Marker

outputs, five

seconds

to

five nanoseconds;

marker

accuracy, within

0.1%.

Tektronix

2901

Time-Mark Generator recommended.

8.

Calibration

Fixture, Constant Amplitude

Signal

Gen-

erator.

Reference frequency, 3

megahertz;

frequency range,

65

megahertz

to

above 200

megahertz; output

amplitude,

0.5

to 5

volts peak to

peak

into 50

ohms;

amplitude

accuracy, output amplitude constant within 1% of 3

megahertz reference as output frequency changes. Tek-

tronix Part

Number

067-0532-01

.

9.

Standard

Amplitude

Calibrator.

Frequency,

1

kHz;

output amplitude, 0.5

mV

to 50 V peak

to

peak in

a

1-2-5

step

sequence; amplitude

accuracy, ±0.25%. Tektronix

calibration

fixture

067-0502-00

recommended.

10.

Differential voltmeter.

Accuracy, within

1%;

resolu-

tion, 50 microvolts. For example.

Fluke Model

825

A

Differential DC Voltmeter.

11.

10X probe. Tektronix Type P6053A recommended.

12.

Cable

(2

each).

Connectors, BNC;

impedance,

50

ohms;

length, 42 inches.

Tektronix

Part Number

012-0057-01.

13.

BNC T

connector. Tektronix Part Number

103-0030-00.

14.

50

ohm feedthrough

termination

(2

each). Tek-

tronix Part Number

01

1-0049-01

.

15.

Adapter.

GR

to

BNC

female. Tektronix

Part

Num-

ber

017-0063-00.

16.

IX

Probe

(2

each). Tektronix P6011

probe

recom-

mended.

Optional Equipment

1.

Plug-In

Extension (Flexible), Tektronix

Part Number

067-0616-00.

(When used with

the vertical plug-in, allows

easier

access

to

adjustments on left side of 7B71

.)

SHORT-FORM

PROCEDURE

7B71

Calibration Date

Calibrated By

—

1. Adjust Upper Positive Slope P-P AUTO

Page

5-5

Level (R251)

Requirement:

Stable triggering

on

a

0.5 division

50

kHz

signal with the

LEVEL/SLOPE

control set

to 1

1

:30.

Performance: Correct

;

Incorrect

2.

Adjust Lower Positive Slope P-P AUTO

Page

5-5

Level (R258)

Requirement: Stable triggering on

a

0.5

division

50

kHz

signal with the LEVEL/SLOPE

control set

to

6:30.

Performance:

Correct

;

Incorrect

3.

Adjust Negative Slope

P-P

AUTO Level

Page

5-5

(R155)

Requirement: Stable triggering on

a

0.5 division

50

kHz

signal with the

LEVEL/SLOPE

control set to

the

negative slope.

Performance: Correct

;

Incorrect

5-2

Performance

Check/Calibration—7B71 (SN

B205000

and

Up)

4.

Check AUTO

Triggering

Sensitivity

Page

5-5

Requirement: Stable triggering on

a

0.3 division

50

kHz

signal with

the

LEVEL/SLOPE

control set near 9:00 and

3:00.

Performance: Correct

;

Incorrect

5.

Check Normal

Triggering Sensitivity

Page

5-6

Requirement: Stable triggering

on

a

0.3 division

50

kHz

signal with the

LEVEL/SLOPE

control set near 9:00

and

3:00.

Performance:

Correct

Incorrect

6.

Adjust DC Level Center (R1

21

)

Page

5-6

Requirement: Stable triggering

on a 0.3 division 50 kHz

signal with

LEVEL/SLOPE

near

9:00 and COUPLING

set

to

DC.

Performance: Correct

;

Incorrect

7.

Check Single Sweep Mode

Page

5-6

Requirement: After each

sweep, further displays

are

locked out until the

RESET

button

is pressed.

Performance: Correct

;

Incorrect

8.

Adjust External Input Balance (R37)

Page

5-6

Requirement: Adjusted for

no potential

difference

between pins

F

and H

of

the

External Input

Amplifier.

Performance:

Balanced

;

Cannot

balance

9.

Adjust External Input Gain (R25)

Page

5-7

Requirement: With

a

one volt

signal applied

to

the

input

the

push-pull output of the External

Input Amplifier

is

0.2 volt.

Performance:

Adjusted:

;

Cannot

adjust.

10.

Check Trigger Bandwidth

Page

5-7

Requirement:

Trigger

bandwidth meets

the specifica-

tions given in Section 1 . Refer

to complete procedure.

Performance: Correct

;

Incorrect list

dis-

crepancies

11.

Check

Internal

Trigger

Jitter

Page

5-8

Requirement:

No more than one

nanosecond

of jitter

with

a 150

MHz

signal applied.

Performance:

Correct

;

Incorrect.

12.

Check

Line

Trigger

Source Page

5-9

Requirement; Stable triggering

of the

proper polarity

on

the

positive and negative

slope of the LEVEL/SLOPE

control.

Performance: Correct

;

Incorrect

13.

Check/Adjust

Sweep Calibration (SWP Page

5-9

CAL,

a front panel adjust)

Requirement: With

1

ms

markers applied

and

TIME/DIV

set

to

1 ms, check for

one marker

each division. The

second

and

tenth

markers must line up

exactly with

their respective

graticule lines.

Performance;

Correct

;

Incorrect

14.

Check/Adjust Magnified Sweep

Gain

Page

5-10

(R785)

Requirement: With TIME/DIV

at 1 ms,

MAGNIFIER

at

XI0and .1 ms markers

applied,

check for one marker

each

division.

Performance:

Correct

;

Incorrect

15.

Check/Adjust Magnifier

Registration

Page 5-10

(R795)

Requirement;

0.2 division

or less trace shift when

switching MAGNIFIER

from

X10

to XI

.

Performance; Correct

;

Incorrect

16.

Check

Variable Time/Div

Page 5-10

Requirement;

Continuously

variable

between

calibrated

settings of the TIME/DIV

switch.

Performance:

Correct

;

Incorrect

17.

Check/Adjust

5

qs

Timing

(C530J)

Page

5-11

Requirement: With

5

qs

markers

applied and TIME/DIV

set

to

5

qs,

check

for one marker each

division.

The

5-3

Performance

Check/Calibration-7B71

(SN

B205000

and

Up)

second

and tenth

markers

must line

up with

their

respective graticule

lines.

Performance;

Correct

;

Incorrect

18.

Check/Adjust

.2 JUS

Timing

(C530L)

Page

5-11

Requirement: With

.1 ps

markers applied

and

TIME/DIV

set

to

.2

jUs, check for

two markers each

division.

Performance:

Correct

;

Incorrect

19.

Adjust

Sweep

Start Linearity

(C537)

Page

5-12

Factory

Adjustment,

see note

on

page

5-12.

20.

Check

Sweep Timing

Accuracy Page

5-12

Requirement:

Accuracy

over

the

center eight

divisions

is

within

3%

from 5

seconds/division

to 1 second/division;

2% from 0.5

second/division

to 0.02

microsecond/

division.

Performance:

Correct

;

Incorrect

list dis-

crepancies

21.

Check

Magnified

Sweep Timing

Page5-13

Requirement:

Magnified

timing

accuracy

over the

center

eight

divisions is within

3.5% from

5 seconds/division

to

1 second/division;

2.5% from

.5

second/division

to

0.02

microsecond

/division.

Performance:

Correct

;

Incorrect

22.

Check/Adjust

Delay Start (R590)

and

Page

5-14

Delay

Stop

(R500)

Requirement;

With the DELAY TIME

MULTIPLIER

set

to 1

.00,

the intensified

portion of the

sweep starts

at

the

second marker; with the DELAY

TIME MULTIPLIER

set

to

9.00,

the intensified

portion of the

sweep starts

at

the

tenth marker.

Performance;

Correct

;

Incorrect

23.

Check Delay Time Multiplier

Accuracy Page

5-15

Requirement;

Accurate within one

minor dial division

at

each

major dial setting between

1.00 and

9.00.

Performance:

Correct

;

Incorrect

24.

Adjust

1

JUS

Sweep

Timing

to

Match

Page

5-15

Delay Time Multiplier

(C530J)

25.

Check Delay

Time Accuracy

Page

5-15

Requirement; Accuracy over the center

eight divisions is

within

1% and 1.5

minor

divisions

for

TIME/DIV

settings of

1

jus

to 0.5 s;

within 1.5% and 1.5 minor

divisions for

TIME/DIV

settings of 1

s to 5

s.

Performance: Correct

;

Incorrect

26.

Check Delay

Time Jitter

Page

5-16

Requirement: Jitter does not

exceed

1

part in 50,000

of

1 0

times the

TIME/D

IV setting.

Performance: Correct

;

Incorrect

27.

Check

Sweep Length Page

5-16

Requirement;

Sweep length

must be

between 10.5

and

13 divisions.

Performance;

Correct

;

Incorrect

28.

Check

Sweep Holdoff

Time

Page

5-17

Requirement;

Holdoff time

is

1.5 times the TIME/DIV

setting or

less for

5

s/Div

to 5jus/Div;

3.5

jus

or less for

2

jus/div

to 0.02

jus/Div.

Performance:

Correct

;

Incorrect

PERFORMANCE

CHECK/CALIBRATION

PROCEDURE

General

The

following procedure is arranged

so

the 7B71 can be

calibrated with the least

interaction of adjustments and

reconnection

of equipment.

The

control

settings continue

from

the preceding

step(s)

unless

noted otherwise.

The

following procedure uses the equipment listed

under

Test

Equipment Required.

If

other equipment

is sub-

stituted,

control settings or calibration setup may need

to

be altered

to

meet the requirements of the equipment used.

Detailed

operating instructions for the test equipment are

not given

in this procedure.

Refer

to

the instruction manual

for the test equipment if more

information is required.

[a

5-4

Performance

Check/Calibration—7B71 {SN B205000

and Up)

NOTE

This instrument shouid be caiibrated

at an

ambient

temperature of

+2ff C ±10°C

for

best

overall

accu-

racy.

If

the temperature is outside the given range, see

Section

1

for the applicable tolerances.

Preliminary Control Settings

7B71 (A Horizontal

Plug

in Compartment)

Installed through

Rigid

Plug

in Extender

LEVEL/SLOPE

Centered on Positive

Slope

(9;00)

TRIGGERING

MODE

P-P

AUTO

COUPLING AC

SOURCE INT

POSITION

MIDRANGE

MAGNIFIER

XI

B

DELAY MODE INDEPENDENT

TIME/DIV

20

/us

VARIABLE CAL IN

7B70 (Test Time Base in

B

Horizontal

Plug in Compartment)

Level/Slope

Triggering

Centered

on

Positive

Slope

(9:00)

Mode

P-P

Auto

Coupling

AC

Source

Int

Position Midrange

Magnifier XI

Display Mode

Time

Base

Time/Div

20

/us

Variable

Time/Div Cal In

7A16A

(Left Vertical

Compartment)

Position Midrange

Polarity

-t

Up

Bandwidth

Full

Volts/Div .5 V

Coupling AC

Oscilloscope

A Intensity CCW (see following

paragraph)

B

Intensity

CCW

Vertical

Mode Left

Horizontal Mode

A

A Trigger

Source

Vert

Mode

B

Trigger Source

Vert Mode

Turn

the Oscilloscope

power on

and advance the A

Intensity

until

a

free-running

trace is

observed. Center

the

trace

with the horizontal

and vertical

Position

controls.

Allow several minutes

warmup

before

proceeding with

calibration. In the following

steps,

whenever

the

B

Hori-

zontal

Mode is selected,

adjust the B

Intensity

to view the

trace. Whenever

theAHorizontal

Mode is

selected, adjust

the A

Intensity

to

view the

trace. When ALT

is selected

it

may be

necessary

to

adjust both

A and B

Intensity.

1. Adjust

Upper

Positive

Slope P-P AUTO

Level (R251)

a.

Apply 0.5 division of

50

kHz

sine wave from the

Type

191

sine-wave

generator to the 7A16A Input

con-

nector. Set the

LEVEL/SLOPE

control

to

11:30 (control

set

near the

top on

the

positive slope).

b.

ADJUST—

R251 for

a stable display. See

Fig. 5-1

for

location of adjustment.

2.

Adjust

Lower Positive

Slope

P-P

AUTO

Level

(R258)

a.

Reset the LEVEL/SLOPE

control

to 6:30 (near the

bottom on the positive slope).

b.

ADJUST—

R258

for

a stable display. RefertoFig.

5-1

for

location of adjustment.

3.

Adjust Negative Slope

P-P

AUTO Level

(R155)

a. Reset the

LEVEL/SLOPE

control

to 3:00 (centered

on the

negative slope).

b.

ADJUST—

R 155

for

a

stable display. Refer

to

Fig,

5-1

for location

of

adjustment.

Check for

stable triggering

over

the full

360°

range of the LEVEL/SLOPE

control.

4.

Check AUTO Triggering

Sensitivity

a.

Set the

TRIGGERING

MODE

to

AUTO.

Adjust the

Type

191

amplitude for

a 0.3 division CRT

display.

b.

CHECK—

For

stable triggering

with the

LEVEL/

SLOPE

control near 3:00 and

near 9:00. Check

for

a

free-running

sweep

at

all other

positions.

0

5-5

Performance

Check/Calibration-7B71

(SN

B205000and

Up)

Fig. 5-1.

Location

of

adjustments on Trigger

Board,

5.

Check

NORMAL

Triggering

Sensitivity

7.

Check SINGLE

SWEEP

MODE

a. Set the TRIGGERING

MODE

to

NORM.

b.

CHECK—

For

stable

triggering

near

9:00 and

near

3:00.

6.

Adjust

DC

Level

Center

(R121)

NOTE

The

7

A 16A

Position

control

must

be

set forzero

volts

DC

between

interface

pins

A20

and

B20 of

the

7B71

before

performing

this

step.

To

accomplish

this,

disconnect

the

top

BNC

connectors

on the

right

side

and

left

side of

the rigid

piug-in

extender

and measure

between

the center

conductors

of

the

female

BNC

jacks.

Then

reconnect the

BNC

connectors.

a. Adjust the

LEVEL/SLOPE

control

for

a stable

display

and change

the TRIGGERING

MODE

to

SINGLE

SWP.

b. CHECK-Remove

the

signal from

the

7A16.

Press the

RESET

button and

check

that the READY

light

is lit.

Reconnect

the

signal

to

the

7A16Aand

check

that the

sweep

runs one

time.

(Increase the

A

Intensity

as

necessary

to

view

the

display, when

step

7 is

completed,

return

the A

Intensity

to

the level

it

was set

at before

step

7.)

At the end

of the

sweep,

the

READY

light

should

go

out.

8. Adjust

External

Input

Balance

(R37)

a.

Set

the TRIGGERING

MODE

to

P-P

AUTO,

COUPLING

to

DC

and SOURCE

to

EXT.

a. Set the

LEVEL/SLOPE

control

near

9:00

for

a stable

display.

b. Connect

the differential

voltmeter

between

pins

F

and H

at

the

rear of the

External

Input

board. See

Fig.

5-2

for

location of pins.

b. ADJUST

-Change

the

TRIGGERING

COUPLING

to

DC

and

adjust

R121

(see Fig.

5-1)

for

a

stable

display.

Return

the TRIGGERING

COUPLING

to

AC.

c. ADJUST—

R37

(see

Fig.

5-1)

for

a

null

read! ng on the

voltmeter.

Use the most sensitive

voltmeter

scale for the

final

adjustment.

5-6

Performance

Check/Calibration—

7B71

(SN B205000 and Up)

Fig.

5-2.

Location of pins for Calibration

Steps 8

and

9.

9. Adjust External Input

Gain (R25)

7B71

TIME/DIV

10

ms

b. Connect

a 200

Hz

sine wave

from the

low-frequency

sine-wave

generator through

a

"T"

connector

and coaxial

cable

to

the 7A16A Input

and from the other

side of the

'T"

connector

through

a

coaxial

cable and

a 2X attenuator

to

the EXT TRIG IN

connector. Adjust

the sine-wave

generator for

a

0.5

division display on the CRT

(adjust the

A Intensity

as

necessary

to

view

the display).

c. CHECK—Using the

control settings

in Table 5-1,

check for stable

triggering and

a lit

TRIG'D

lamp

for each

condition

listed. Use the TIME/DIV

control

as

necessary

for optimum viewing

of display.

TABLE

5-1

NOTE

Step

9 requires two 7A 16A amplifiers or

a dual trace

amplifier

such as

the

7A

12.

a.

Change

the 7B71 TIME/DIV

to .2 ms.

b.

Apply

a

one volt

signal from the

standard

amplitude

calibrator

to

the EXT TRIG IN

connector.

c. Set the Oscilloscope Vertical

Mode

to

Add.

Set both

7A16A

Volts/Div controls

to 50

millivolts.

Set the

Polarity

switch of the 7A16A

in the right vertical

compartment

to

Invert.

Connect

a IX probe from the left vertical plug

in

to

pin

F

on

the External

Input

board

and

a

1 X probe from the

right

vertical plug in

to

pin H

on

the

External Input

board.

7B71

Sine-Wave

Generator

COUPLING

SOURCE

Frequency

Amplitude

AC INT

200

Hz

0.5 div

AC

HF

REJ

INT

200 Hz

0.5 div

DC

INT

200 Hz

0.5 div

AC LF

REJ INT

30 kHz

0.5 div

AC HF REJ

INT

50 kHz

0.5 div

AC EXT

200 Hz

125 mV

AC HF

REJ EXT

200 Hz

125 mV

DC EXT

200 Hz

125

mV

AC LF REJ

EXT

30 kHz

125

mV

AC HF REJ

EXT

50 kHz

125 mV

d. Change the "T"

connector from

the low-frequency

generatortothe Type

191 signal

generator output

con-

nector

(using

a

GR

to

BNC

adapter). Set the Type

191

frequency

to 20

MHz

and adjust

the amplitude for

125

millivolts.

d. ADJUST—

R25

(see Fig, 5-1)

for

a four division

display

on the CRT,

e. CHECK—

Using the

control

settings

in Table 5-2,

check

for

stable triggering

and

a

lit TRIG'D

lamp for

each

condition

listed.

Partial

Procedure

To

begin

a

partial

procedure with this

step, set the

controls

as

given under

Preliminary

Control Settings

except

as

follows:

TIME/DIV

10

ms

10. Check

Trigger

Bandwidth

a.

Set the

controls

as

given

under

Preliminary

Control

Settings

except

as

follows:

TABLE

5-2

7B71

Type 191

COUPLING

SOURCE

Frequency

Amplitude

AC

EXT

20 MHz

125 mV

DC

EXT

20

MHz

125 mV

AC LF REJ

EXT

20

MHz

125 mV

AC

INT

20

MHz

0.5 div

DC

INT

20

MHz

0.5 div

AC LF REJ

INT

20 MHz

0.5 div

5-7

Performance

Check/Calibration-7B71

(SIM

B

205000

and

Up)

f.

Change

the

"T"

connector from

the Type

191 signal

generator

to

the

067-0532-01

Calibration Fixture

output

connector.

Set the

Calibration Fixture

frequency

to

200 MHz

and adjust the

amplitude

for

a 1.5 division

display. Adjust TIME/D

IV

to

provide

several

cycles of

triggered display.

g.

CHECK-Using

the

control

settings

in

Table 5-3,

check

for stable

triggering

and

a

lit TRIC'D

lamp

for

each

condition

listed.

TABLE

5-3

7B71

Calibration

Fixture

COUPLING

SOURCE

Frequency

Amplitude

AC

INT

200

MHz

1 .5 div

DC

INT

200 MHz

1

.5

div

AC LF

REJ

INT

200

MHz

1

.5 div

AC

EXT

200 MHz

375

mV

DC

EXT

200 MHz

375 mV

AC LF

REJ EXT

200 MHz

375 mV

h.

Set the 7B71 COUPLING

to

AC

and SOURCE

to

I

NT.

Change

the "T"

connector

from

the

067-0532-01

calibration

fixture

to

the

low frequency

sine-wave

generator

output connector.

Adjust the

sine-wave

generator

for

a 0.3

division

30

Hz

display.

Change the

7B71 TIME/DIV

to

provide

several

cycles of

display.

Reset the TRIGGERING

MODE

to

NORM.

Slightly

adjust the

LEVEL/SLOPE

control

as necessary

for stable

triggering.

i. CHECK—

Using the

control

settings in

Table 5-4,

check

that the

sweep

can be

triggered

by

adjusting

the

LEVEL/SLOPE

control

and that

the TRIC'D

lamp

lights

for

each condition

listed.

TABLE

5-4

7B71

i

Sine-Wave

Generator

COUPLING

SOURCE

Frequency

Amplitude

AC

INT

30 Hz

0.3 div

AC

HF REJ INT

30 Hz

0.3

div

DC INT

30 Hz

0.3 div

AC LF REJ

INT

30 kHz

0.3 div

AC HF

REJ INT

50 kHz

0.3 div

AC EXT

30 Hz

75 mV

AC

HF REJ EXT

30 Hz

75 mV

DC

EXT

30 Hz

75 mV

AC

LF REJ EXT

30 kHz

75 mV

AC HF REJ

EXT

50

kHz

75 mV

j.

Change the 'T"

connector

from the

low-frequency

generator

to

the Type

191 signal

generator

output

con-

nector (using

a

GR

to

BNC

adapter). Set

the Type

191

frequency

to 20

MHz

and

adjust the

amplitude

for

75

millivolts.

k.

CHECK—

Using the control

settings

in Table 5-5,

check

for stable

triggering and

a lit

TRIC'D

lamp

for each

condition listed.

Adjust A Intensity

and LEVEL/SLOPE

for

optimum

viewing of the

triggered display.

TABLE

5-5

7B71

Type 191

COUPLING

SOURCE

Frequency

Amplitude

AC

EXT

20 MHz

75 mV

DC EXT

20

MHz

75 mV

AC

LF REJ

EXT

20 MHz

75 mV

AC INT

20

MHz

0.3 div

DC INT

20

MHz

0.3 div

AC

LF

REJ INT

20

MHz

0.3

div

I.

Change the

'T"

connector

from the

Type

191 signal

generator

to

the

067-0532-01

Calibration

Fixture

output

connector. Set the

Calibration Fixture

frequency

to

200

MHz

and

adjust

the

amplitude

for

a

1.5 division

display.

m. CHECK—

Using the control

settings in

Table

5-6,

adjust

LEVEL/SLOPE

control for

a

stable

triggered display

and check

for

a

lit TRIC'D

lamp for each

condition listed.

TABLE

5-6

7B71

Calibration

Fixture

COUPLING

SOURCE Frequency

Amplitude

AC INT

200 MHz

1.5 div

DC

INT

200

MHz

1 .5 div

AC LF REJ

INT 200 MHz

1.5 div

AC EXT

200 MHz

375 mV

DC EXT

200 MHz

375 mV

AC

LF

REJ EXT

200 MHz

375 mV

11.

Check

Internal

Trigger Jitter

a.

Set the 067-0532-01

Calibration

Fixture

to 150

MHz

and adjust

the amplitude

for

a

four

division

display.

5-8

Performance

Check/Calibration-7B71

(SN

B 205000 and Up)

b. Set the 7B71

TIME/DIV

to .02

microsecond,

MAG

IMIFIER

to X10,and SOURCE

to

INT.

c. CHECK—For

stable triggering

of the proper

polarity

with the

LEVEL/SLOPE

control set

to the positive

slope

and

to

the negative

slope.

c. CHECK-For

no

more

than

0.5 division

(1 nano

second)

of

jitter.

Disregard

any

slow

drift.

Partial Procedure

To

begin

a

partial

procedure with

this

step, set the

controls

as

given

under Preliminary

Control Settings

except

as follows:

12.

Check

Line

Trigger

Source

7A16A

a. Change the

control

settings

as follows

VOLTS/D

IV

TIME/DIV

TRIGGERING

MODE

COUPLING

SOURCE

MAGNIFIER

TIME/DIV

13. Check/Adjust

Sweep

Calibration

(SWP

|

CAL,

a front-panel

adjustment)

^

a. Set the 7B71 TIME/DIV

to 1 ms, SOURCE

to

INT

and TRIGGERING

MODE

to

P-P

AUTO,

7A16A

Volts/Div

Coupling

b.

Apply

1

ms

markers

from the

2901

time-mark

generator

to

the

7A16A Input

through

a

50 cable and

a

50

L2

termination.

b. Connect

a IX probe

from the

7A16A

input

to

interface

connector A4

(plug-in

connector

at rear

of

the

7B71).

See

Fig.

5-3.

c.

CFIECK—

CRT

display

for

one

1 ms marker

for

each

division

between

the

second

and

tenth

vertical

lines

(see

Fig. 5-4).

NOTE

Unless

otherwise

noted,

use

the

center

eight

hori

zontal

divisions

when

checking

or

adjusting

timing.

PERFORMANCE

CHECK

ONL

Y

Plug-m

Extender

Front-pane!

adjustment;

can be

adjusted

as

part

of

the

performance

check.

7B71

<•—

The

timing

accuracy

is

within

5% over

any

interval

within

the

center

eight

divisions.

Fig. 5-3,

Location

of

interface

connector

A4

5-9

Performance

Check/Calibration-7B71

(SN

B205000 and

Up)

Fig.

5-4.

CRT display showing

SWP CAL adjustment

correctly

set.

g.

INTERACTION:

Check

steps

14,

15, 16, 17,

18,

20,

and 21

.

14.

Check/Adjust

Magnified

Sweep

Gain

(R785)

a. Set the time-mark generator

for .1 ms

markers.

b.

Setthe7B71 MAGN

IFIER

to X10.

c. CHECK—CRT

display for

one .1 ms marker

for each

division between the second

and tenth

vertical lines.

d.

ADJUST—

R785,

Magnifier

Gain (left side

toward

rear), for one marker

each division. The

second

and tenth

markers must coincide

exactly with

their respective

grati-

cule

lines (use the horizontal POSITION

control

as

neces-

sary

to

line up the display).

e.

CHECK—

Timing

accuracy

is within

5% over any

two

division interval within the

center

eight divisions.

f. INTERACTION:

Check

steps

15 through

18

&

20,

21

.

15.

Check/Adjust

Magnifier

Registration

(R795)

b. Position the middle marker

to

the

center vertical line

(there

are three markers on the

total

magnified sweep) with

the horizontal POSITION

control.

See Fig. 5-5A.

Fig.

5-5.

CRT

display

showing correct

magnifier registration.

(A)

MAGNIFIER

set

to

X10 and

(B)

MAGNIFIER

set to XI.

c.

CHECK—

Set the MAGNIFIER

to XI and check that

the middle

marker remains

at the center vertical line.

See

Fig.

5-5B.

d.

ADJUST—

Mag

Regis, R795

(left

side, rear),

to

position the

middle marker

to

the

center vertical

line.

e.

Alternately

switch

the MAGNIFIER

between

XI and

X10

and

repeat

steps

b through

e until

no shift

occurs when

switching.

16.

Check

Variable

Time/Div

a.

Set the time-mark

generator for

5

ms

markers. Set the

7A16A

Volts/Div

to 1

V.

a.

Reset

the 7B71 TIME/DIV

to 2

ms

and MAGNIFIER

to XI. Set the

time-mark

generator

for

10 ms markers.

5-10

Performance

Check/Calibration-7B71

(SN

B205000 and

Up)

b. Press

and

release the

VARIABLE

TIME/DIV

knob

and turn

fully

counterclockwise.

c. CHECK—

CRT

display

for

a two-d

ivision

maximum

spacing

between

markers

(indicates

adequate range

for

continuously

variable

sweep

rate

between

the

calibrated

steps;

see

Fig,

5-6).

Return

the VARIABLE

TIME/DIV

to

the

CAL IN

position.

Fig. 5-6.

Typical

CRT

display

when

checking

VARIABLE

control

range.

d. ADJUST

-C530J

(left

side

toward

front)

for

one

marker

each

division.

The

second

and

tenth

markers

must

coincide

exactly

with their

respective

graticule

lines.

r

1

B

m
I

H

1

Fig. 5-7.

CRT

display

showing

correct

5

ps

timing.

18.

Check/Adjust

.2

jus Timing

(C530L)

a. Set

the

time-mark

generator

for

.1

jds

markers.

b.

Set the

7B71

TIME/DIV

to

.2

/is.

NOTE

For

the

following

steps,

the

7B71

must

be

installed

inside

the

oscilloscope

(not

on

the

extender).

The

7B70

Test

Time-Base

plug-in

may

be

removed

and

the

7B71

temporarily

installed

in

the

right

(B) horizontal

compartment.

If

the

7B71

is

placed

in

the

B

compartment,

set

the

Horizontal

Mode

to

B and

adjust

the

B Intensity

as

necessary

to view

the

trace.

If

the

optional

flexible

plug-in

extender

is available,

the

7A

16A may

be

connected

through

it.

This

will

provide

easier

access

to the

adjustments

on the left

side of

the

7B71

.

17.

Check/Adjust

5

p%

Timing

(C530J)

a.

Set

the

time-mark

generator

for

5

ps markers.

b. Reset

the 7B71

TIME/DIV

to

bps

and

adjust

the

LEVEL/SLOPE

for

a

stable

display.

c. CHECK—

CRT

display

for

one

marker

each

division

between

the

second

and

tenth

vertical

lines.

Check

that

sweep

timing

is within

0.16

division

(2%)

over

the

center

eight

divisions.

See Fig.

5-7.

c.

CHECK—

CRT

display

for

two

markers

each

division

over

the

center

eight

divisions.

Check

that

sweep

timing

is

within

0.16

division

(2%)

over

center

eight

divisions.

See

Fig.

5-8.

Fig. 5-8.

CRT

display

showing

correct

0.2 jus timing.

5-11

Performance Check/Calibration—

7B71

(SN

B205000

and

Up)

cl.

ADJUST—

C530L (left side

below C530J) for

two

markers each division.

The

markers

at

the second and tenth

vertical lines must coincide

exactly with their respective

graticule lines

(use the horizontal POSITION

control

as

necessary

to

line

up

the

display).

19.

Adjust

Sweep

Start Linearity

(C537)

Refer

to

the

following Note before

attempting

adjust-

ment of C537.

NOTE

C537

is

a

factory adjustment

and normally

should

not require readjustment unless:

Ij C537

is

replaced

because

of breakage

or other defect;

2)

associated

major components replaced;

3j

C537

has accidentally

been mis-adjusted. Gross

misadjustment of C537

can

result

in

waveform instability

and sweep foldover

near the

start

of the sweep.

C537 adjustment

is

effective only with higher performance

main-frames

such as

the 7900-series, and may

be adjusted

to

optimize the performance of the

plug-in and main-

frame

as

a package. This adjustment should

be made

with the 7B71 installed in the

highest performance

main-frame

it

will be used with.

C537 primarily

affects the first two screen diameters following

the

excluded first 12

ns

of sweep

at

the highest magnified

sweep speed.

a.

Install

the 7B71 in the right (B) horizontal compart-

ment (not

on the extender), and set the controls

as

specified

under Preliminary Control Settings except

as

follows:

7B70

(Removed

from

the oscilloscope)

Oscilloscope

Horizontal Mode

Vertical Mode

B

Intensity

B

Left

Adjust for Visible Display

7B71

TIME/DIV

POSITION

MAGNIFIER

.02 ps

Start of sweep near first

graticule line

X10

Markers

Time Mark Generator

5

ns

7A16A

Volts/Div Adjust for about

3

divi-

sions display amplitude

b.

ADJUST—

C537

(bottom left side forward of center)

for best

linearity of the 12 ns to 52

ns portion of

the

sweep

start. Position the first

(excluded) 12 ns portion of the

sweep off screen to

the left. Adjust C537

for

best

overall

linearity of

the next

40

ns portion of the sweep (three

cycles./five graticule

divisions).

20. Check Sweep

Timing Accuracy

a.

With the

7B71 MAGN

IF

lER

set

to

XI

,

and using the

control settings

given in Table

5-7, check

that sweep timing

accuracy over

the center eight

divisions of the

display

is

within the allowable

limits.

TABLE

5-7

7B71

TIME/DIV

2901

Markers

Markers/

i

Div

Allowable

Error

.02

ys

20 ns

1

±0.16

div

.05

ys

50

ns

1

.1

ys .1

ys

1

.2

ys .1

ys

2

.5

ys

.5

ys

1

1

ys

1

ys

1

2

ys

1

ys

2

5

ys

5

ys

1

10

ys 10

ys

1

20

ys 10

ys

2

50 ys

50 ys

1

.1 ms

.1 ms

1

.2 ms

.1 ms

2

.5 ms .5

ms

1

1 ms

1 ms

1

2

ms

1

ms

2

5 ms

5

ms

1

10 ms

10 ms

1

20 ms

10 ms

2

50

ms

50

ms

1

.1 s

.1 s

1

,2 s

.1 s

2

.5 s

.5 s

1

1 s

1 s

1

2s

1 s

2

+0.24

div

5 s

5 s

1

5-12 a

21.

Check

Magnified

Sweep

Timing

a,

CHECK-With

the

MAGNIFIER

set

to X10, use

the

control

settings

given

in Table

5-8

to check

timing

accuracy

over the

center

eight

divisions.

Adjust

the

Vertical

Position

and

Volts/Div

controls

as

necessary

to provide

a centered

two-division

amplitude

time-mark

display.

b. Reset the MAGNIFIER

to XI.

Performance

Check/Calibration-7B71

(SN

B205000 and

Up)

DELAY

TIMING

Return

the 7B71

to the

left (A)

horizontal

compartment

through

the rigid

extender.

Install

the

Test

Time-Base

in the

right (B)

horizontal

compartment.

Change

the

control

settings

as

follows;

Time

Mark

Generator

Markers

1

ms

Oscilloscope

Horizontal

Mode

A

A

Intensity

For

a viewable

display

TABLE

5-8

7B71

(on

rigid

extender)

7B71

TIME/DIV

2901

Markers

Markers/

Div

Allowable

Error

.02

Os

10

ns 1 cycle/5

div

0.13

div/5

div

.05

Os

5 ns

1

±0.2

div

.1

Os

10 ns

1

.2

Os

20

ns

1

.5

Os

50

ns

1

1

Os

.1

Os 1

2

os

.1

Os 2

5

Os .5

Os 1

10

Os

1

Os

1

20

os

1

Os

2

50

Os

5

os 1

.1 ms

10

os 1

,2

ms

10

Os

2

.5

ms

50

Os

1

1

ms

.1 ms

1

2 ms

.1

ms

2

5

ms

.5 ms

1

10

ms

1

ms

1

20

ms

1

ms

2

50 ms

5

ms

1

.1

s

10

ms

1

.2

s

10

ms

2

.5

s

50

ms

1

1 s

.1 s

1

±0.28

div

2s

.1 s

2

5 s

.5 s

1

LEVEL/SLOPE

TRIGGERING

MODE

COUPLING

SOURCE

MAGNIFIER

B DELAY

MODE

TIME/DIV

DELAY

TIME

MULTIPLIER

Centered

on positive

slope

P-P

AUTO

AC

INT

XI

B

STARTS

AFTER

DELAY

1

ms

1.00

Test

Time-Base

(7B70)

Level/Slope

Triggering

Mode

Coupling

Source

Magnifier

Display

Mode

Time/Div

Centered

on

positive

slope

Norm

AC

Int

XI

Time

Base

1

0

Ids

Volts/Div

7A16A

Adjust

for

about two

divi-

sions

of

display

amplitude

El

5-13

Performance

Check/Calibration-7B71

(SN B205000

and

Up)

22.

Check/

Adjust

Delay

Start

(R590)

and

Delay

Stop (R500)

e. Reset

the 7B71 DELAY

TIME

MULTIPLIER

to

9.00.

a.

With the 7B71 DELAY

TIME

MULTIPLIER

fully

counterclockwise,

check that

0.00

is aligned

with the

index.

f. CHECK—

The intensified

portion

of the

sweep starts

at

the

tenth marker. See

Fig.

5-9B.

b. Set the time-mark

generator

for

1

ms

markers.

Adjust

the LEVEL/SLOPE

for

a

display

triggered

on the

positive

slope. Set the DELAY TIME

MULTIPLIER

to 1.00.

c.

CHECK—

The intensified

portion

of the

sweep

starts

at

the

second marker.

See

Fig.

5-9A.

g.

ADJUST—

Delay Stop

R500

(left side

bottom, for-

ward of center)

so

the

intensified portion

starts

at

the tenth

marker.

h.

Change the

Oscilloscope

Horizontal

Mode

to Alt and

the 7B71 DELAY TIME

MULTIPLIER

to 1.00.

d.

ADJUST—

Delay Start

R590

(left side

forward of

center)

so

the intensified

portion of the

sweep starts

at the

second marker.

i. CHECK—

The delayed (B)

sweep

starts

at

the

first

marker. See lower

trace in

Fig. 5-10.

j.

ADJUST—

Delay start

(R590)

so

the

delayed

sweep

starts

at

the first marker.

i

y

!

1*5

Ik

A

TEN

PORI

3IFIED

|ON

9

I

Fig.

5-9.

Typical

CRT display showing

correct

adjustment

of

(A)

Delay

Start and

(B) Delay Stop.

k. Reset the

DELAY

TIME

MULTIPLIER

to 9.00.

l. CHECK—

The delayed

sweep starts

at the first

marker.

m. ADJUST—

Delay

Stop

(R500)

so

the

delayed sweep

begins

at the first marker.

NOTE

The

Delay Start

and Delay

Stop adjustments

interact.

Repeat

steps b through

m as necessary.

Fig. 5-10.

Typical

CRT display

when checking

delay

adjustments.

5-14

El

Performance

Check/Calibration—

7B71 |SN

B205000

and

Up)

23.

Check Delay Time Multiplier

Accuracy

a.

Set the 7B71

DELAY

TIME

MULT

near 8.00sothe

delayed sweep begins

at

the

ninth marker.

b. CHECK-The DELAY TIME

MULTIPLIER

deviation

from 8.00

is

within

one minor

division.

c.

Repeat this check

at each

major dial

setting of the

DELAY

TIME MULTIPLIER

between

1.00 and

9.00.

e. Change

the Horizontal

Mode

to

ALT

and B DELAY

MODE

to

B STARTS AFTER

DELAY.

f. Set the Vertical Position

control

to move

the A

Sweep trace

to

the portion

of the

graticule

above the

center

horizontal line.

g.

Set the Vertical

Trace

Separation

control

on the

oscilloscope

to position the

Delayed (B)

Sweep

trace in

the

lower

half of the graticule

area.

24.

Adjust

1

(US

Sweep Timing

to Match

Delay

Time Multiplier

(C530J)

a.

Remove

the 7B71 from

the

rigid extender

and

install

it in the left (A)

horizontal

compartment.

If

the

optional

flexible

extender

is available,

connect the

7A16A

through

it

to allow easier

access

to

C530J.

h. ADJUST—

The DELAY TIME

MULT

knob

slightly,

so

the

leading edge of the Delayed

Sweep

trace time

mark

intersects

the junction of

the center

vertical graticule

line

and

a

horizontal graticule line,

while

keeping the

intensified

zone

at

the second

time mark.

Note this

intersecting

point

for future

reference.

b. Change the following

control

settings:

i. Read

the DELAY

TIME

MULT

dial,

add 8.00

to this

figure

and record

it for reference

during

the

next

step.

Time Mark

Generator

Time

Markers

1

ns

j.

Rotate the DELAY

TIME

MULT

dial

to read the

number

recorded

in step i (the

intensified

zone of

the A

Sweep trace

should

be near the

tenth

time

mark).

7B71

TIME/DIV

^

ns

DELAY TIME

MULT

Near 1.00

7B70

Time/Div

,02

ns

7A16A

Volts/Div

Adjust for

about

two divi-

sions

display

amplitude

Oscilloscope

Horizontal

Mode

A

c. Set the 7B71 LEVEL/SLOPE

for

a

stable

display and

check the CRT

display

for one

marker/division

over the

center eight divisions.

d.

ADJUST—

C530J

(left side

toward front)

for one

marker

each division over the

center

eight divisions. The

markers

at

the second

and tenth

graticule lines

must

coincide

exactly.

k.

ADJUST—

C530J

so

the

leading

edge

of the

time

mark

in the

lower trace

intersects

the

same

vertical

and

horizontal

graticule

lines

as

it did

in step

23h

(the

intensified

zone of the A

sweep

trace

should

still

be

at

the

tenth

time

mark).

25.

Check Delay

Time

Accuracy

a. Set the 7B71

DELAY

TIME

MULTIPLIER

near

1.00.

b.

CHECK—

Using

the

settings given

in Table 5-9, check

the

delay time

accuracy

is within the

given

tolerance.

First

set

the

DELAY

TIME

MULTIPLIER

near 1.00.

Adjust the

DELAY

TIME

MULTIPLIER

until

the

beginning

of the

Delayed

(B)

Sweep

starts

at

the

second

marker

(second A

Sweep

time-marker

intensified,

and

the nearest

Delayed (B)

Sweep

marker

aligned

with the

first

graticule line);

note

the

dial

reading.

Second set the DELAY

TIME

MULTIPLIER

near

9.00 and

adjust until the

beginning of

the

delayed

sweep

starts

at the tenth

marker

(tenth

A Sweep

time-

marker

intensified,

and

nearest

Delayed (B)

Sweep

marker

at

the

first vertical

graticule

line);

note the

dial

reading.

Subtract the

first

reading from

the

second

reading. The

difference

must be eight

divisions +

or

—

the

allowable

error

given

in Table

5-9.

5-15

Performance

Check/Calibration-7B71

(SN

B205000 and

Up)

TABLE

5-9

7B71 Test

Time-Base

2901

Allowable

DELAY TIME

TIME/DIV

Markers

Error

1

ys

.1

ys

1

ys

2

ys

.1

ys

1

ys

5

ys

.5

ys

5

ys

10

ys

1

ys

10 ys

20

ys

1

ys

10

ys

50

ys

5

ys

50

ys

.1 ms

10 ys .1

ms

5.5

minor

dial

.2

ms

10

ys

.1

ms

divisions

.5 ms

50

ys

.5

ms

10

ms

1 ms

10

ms

20 ms

1 ms

10

ms

50

ms

5

ms

50 ms

.1

s 10

ms

.1 s

.2

s

10 ms

.1 s

.5 s

50 ms

.5

s

1 s

.1

s

1

s

7.5

minor dial

2 s

.1

s

1

s

divisions

5 s

.5

s

5s

26.

Check Delay

Time

Jitter

a.

Change

the

control

settings

as follows (it

may

be

necessary

to

use

a

viewing

hood

to see

the display

in this

step):

7A16A

Volts/Div

1 V

7B71

TIME/DIV

1

ms

DELAY

TIME

MULTIPLIER

10.00

Time/Div

Test

Time

Base

.2 JUS

b.

Set

the

time-mark

generator

for

1

ms

markers.

Rotate

the DELAY

TIME

MULTIPLIER

until

the eleventh

A

Sweep

time marker

is intensified,

then

rotate it slightly

to

position the

nearest B

Sweep

marker

to the center

of the

CRT.

c.

CHECK—

Jitter on

the leading

edge of the

pulse

does

not

exceed

1 division

(1

part in

50,000 of

10

times

the

TIME/DIV

setting). See Fig.

5-1

1 .

Disregard

any slow

drift.

27.

Check Sweep

Length

b.

Set the

time-mark

generator

for

1

ms

and

.1 ms

markers.

Reset

the B

DELAY

MODE

to INDEPENDENT,

Volts/Div

to 2

V

and the

Oscilloscope

Horizontal

Mode

to

A.

Adjust

the 7B71

LEVEL/SLOPE

for

a

stabi

e display.

c. Move the

eleventh

1 ms

marker

to

the

center

vertical

line

with

the horizontal

POSITION

control.

See Fig. 5-12.

d. CHECK-Sweep

length

must

be

between

10.5

and 13

divisions.

e.

Disconnect the

time-mark

generator.

1

V

:

1

eS

2001

s

1

',

. . .

7

Fig.

5-1

1 .

CRT display

showing delay

time jitter.

a. Change the 7B71

TRIGGERING

MODE

to

NORM.

Fig.

5-12.

CRT display when checking

sweep

length.

Performance

Check/Calibration-7B71

(SN

B205000 and

Up)

28.

Check

Sweep Holdoff

Time

7A16A

a.

Connect

a 10X probe

from

the 7A16

to

TP566

(left Volts/Div

Set for

about

two divi-

side

back, near R785)

on

the 7B71

Time

Base

board.

sions

display

amplitude

b. Change

the control

settings

as follows;

Oscilloscope

Horizontal

Mode

A Trigger

Source

B Trigger

Source

7B71

TRIGGERING

MODE

COUPLING

SOURCE

B DELAY

MODE

TIME/DIV

MAGNIFIER

7B70

Level

/Slope

Triggering

Mode

Coupling

Source

Display

Mode

Magnifier

Tirrie/Div

B

Right

Vert

Left

Vert

P-P

AUTO

AC

INT

INDEPENDENT

Per

Table

5-10

XI

Centered

on

Positive

Slope

Norm

AC

Int

Time

Base

XI

Per

Table

5-10

Fig.

5-13.

CRT display

when

checking

sweep holdoff

time.

c. CHECK—

The

holdoff

time

(see Fig.

5-13)

corres-

ponds

with

the values

given

in

Table

5-10.

TABLE

5-10

7B71

TIME/DIV

7B70

TIME/DIV

HOLDOFF

(Equal

or less than)

.02

MS

.5

MS

3.5

MS

.05

MS

.5

MS

3.5

MS

.1

MS

1

MS 3.5

MS

.2

MS

1

MS 3.5

MS

.5

MS

5

MS

3.5

MS

1 MS

5

MS

3.5

MS

2 MS

5 MS

3.5

MS

5 MS 1

0

MS

7.5

MS

10

MS

20

MS

1

5

MS

20

MS

50

MS

30

MS

50

MS .1 ms

75

MS

.1 ms

.2 ms

.1

5

ms

.2

ms

.5 ms

.3 ms

.5 ms

1 ms

.75

ms

1

ms

2 ms

1

.5

ms

2

ms

5 ms

3 ms

5

ms

1

0 ms

7.5

ms

10 ms

20 ms

1

5

ms

20 ms

50 ms

30 ms

50

ms

.1

s

75 ms

.1

s

.2

s

.15

s

.2

s

.2

s

.15

s

.5

s

.2

s

.15

s

1 s

.2

s

.15

s

2

s

.2

s

.15

s

5 s

.2

s

.15

s

This

completes

the

calibration

of

the 7B71

Delaying

Time

Base.

5-17

Section

6-7B71

(SN

B205000-up)

ELECTRICAL

PARTS

LIST

Replacement parts should

be ordered from

the Tektronix

Field

Office

or Representative

in your

area.

Changes to Tektronix products

give

you the benefit

of

improved

circuits and

components.

Please

include

the instrument

type number and serial

number with

each order

for

parts or service.

ABBREVIATIONS AND REFERENCE

DESIGNATORS

A

Assembly, separable

or

FI Filter

PTM paper or

plastic,

tubular

repairable

H

Heat dissipating

device

molded

AT Aftenuafor, fixed or

variable

(heat sink,

etc.)

R Resistor,

fixed

or

variable

B

Motor

HR

Heater

RT Thermistor

BT

Battery

J

Connector,

stationary

portion

S

Switch

C

Capacitor, fixed or

variable

K

Relay

T Transformer

Cer Ceramic

L

Inductor, fixed

or variable

TP Test point

CR

Diode, signal

or

rectifier LR

Inductor/resistor

combination

U

Assembly,

inseparable

or

CRT cathode-ray

tube

M

Meter

non-repairable

DL

Delay line

Q

Transistor

or

silicon-

V Electron

tube

DS Indicating

device (lamp)

controlled

rectifier

Var Variable

Elect.

Electrolytic

P

Connector,

movable portion

VR Voltage

regulator

(zener

diode.

EMC electrolytic,

metal

cased PMC Paper,

metal

cased

etc.

)

EMT electrolytic,

metal

tubular PT

paper,

tubular

WW

wire-wound

F Fuse

Y Crystal

Ckt.

No.

Tektronix

Part

No.

Serial/Model

Eff

No.

Disc

Description

CHASSIS

BULB

DS347

150-0048-01

Incandescent

#683, selected

CAPACITORS

C530A'

lOuF,

C530B

luF,

C530E

295-0165-00

O.luF,

Timing

capacitor

assembly

C530F

O.OluF,

C530H,

'

995pF,

CONNECTOR

J1 131-0955-00

Receptacle,

electrical,

BNC

RESISTORS

R146AI

2

311-0912-00

2.5K

ohm,

Var

R146BI

lOK

ohm,

Var

R505 311-0946-00

5 OK

ohm,

Var

R740 311-0486-00

500

ohm,

Var

R744A|

311-1162-00

lOK

ohm,

Var

R744B

1

lOK

ohm

,

Var

SWITCH

S146 311-0972-00

SLOPE

Individual

timing

capacitors

in the

assembly

must be

ordered

by

the

9-digit

part number,

letter

suffix

and

tolerance

printed

on

the

timing

capacitor

to

be

replaced.

The

letter

suffix and

tolerance

should

be

the

same

for

all

of

the

timing

capacitors

in

the

assembly.

EXAMPLE:

285-XXXX-XX

II

^Furnished

as a

unit with

S146.

REV.

B

NOV. 1974

6-1

Electrical

Parts

List—7B71

(SIM B

205000-up)

Ckt.

No.

Tektronix

Part

No.

Serial/Model

Eff

No.

Disc

Description

670-1144-00

EXTERNAL INPUT

Circuit Board

Assembly

CAPACITORS

Cl

281-0534-00

3.3pF, Cer, 200V, !0.25pF

C2

283-0068-00

O.OluF,

Cer, 500V,

+100%-0%

C3

283-0080-00

0.022UF, Cer, 25V,

+80%-20%

C5

281-0718-00

15.8pF, Cer, 500V,

1%

C6

283-0080-00

0.022UF, Cer,

25V,

+80%-20%

CIO

281-0632-00

35pF, Cer,

500V,

1%

C12 281-0653-00

3.3pF, Cer,

20V, !lpF

C13

281-0534-00

3.3pF,

Cer,

I0.25pF

G15

281-0610-00

2.2pF,

Cer, 200V, lO.lpF

C31

283-0156-00

lOOOpF,

Cer, 200V, 10%

C39

283-0156-00

lOOOpF,

Cer, 200V,

10%

C55

283-0080-00

0.022UF, Cer, 25V,

+80%-20%

C57

283-0080-00

0.022UF, Cer, 25V,

+80%-20%

DIODE

CR15

152-0246-00

Silicon, CD12676 or FD3375

RELAYS

K3

148-0035-00

Armature, spdt,

15V

DC

K6

148-0034-00

Armature, dpdt,

15V DC

TRANSISTORS

Q20A,B

151-1009-00

Silicon, FET, N channel junction, dual

Q30

151-0221-00

Silicon, PNP, 2N4258

Q37

151-0221-00

Silicon, PNP, 2N4258

RESISTORS

R1

315-0270-00

27

ohm, 0.25W,

5%

R2

315-0101-00

100 ohm, 0.25W,

5%

R5

323-0452-00

499K ohm, 0.50W,

1%

R7

321-0452-00

499K ohm, 0.125W, 1%

R8

321-0448-00

453K ohm, 0.125W,

1%

RIO

315-0390-00

39 ohm, 0.25W,

5%

Rll

321-0361-00

56. 2K ohm, 0.125W,

1%

R12

315-0270-00

27 ohm, 0.25W,

5%

R15

315-0100-00

10 ohm, 0.25W,

5%

R16

315-0270-00

27 ohm, 0.25W,

5%

R20

315-0101-00

100

ohm, 0.25W,

5%

R22

315-0392-00

3.9K ohm, 0.25W,

5%

R23

315-0391-00

390 ohm, 0.25W,

5%

R25

311-0634-00

500 ohm, Var

R26

315-0392-00

3.9K ohm, 0.25W,

5%

R27

315-0270-00

27 ohm, 0.25W, 5%

R28

315-0101-00

100 ohm, 0.25W,

5%

R31

315-0331-00

330 ohm,

0.25W, 5%

6-2

REV. C

NOV. 1974

Electrical

Parts

List-7B71

(SIM

B2D5000-up)

Ckt.

No.

Tektronix

Part

No.

Serial/Model

No.

Eff

Disc

Description

RESISTORS

(cont)

R33

321-0185-00

825 ohm,

0.125W, 1%

R34

315-0360-00

36K ohm,

0.25W, 5%

R36

321-0174-00

634 ohm,

0.125W, 1%

R37

311-0634-00

500

ohm

,

Var

R39

315-0331-00

330 ohm,

0.25W, 5%

DIODE, ZENER

VR25

152-0127-00

Zener,

1N755A,

0.4W,

7.5V, 5

670-1141-04

TRIGGER Circuit

Board

Assembly

CAPACITORS

C44

283-0080-00

0.022UP,

Cer 25V,

+80%-20%

C48

283-0000-00

O.OOluF,

Cer, 500V, 10%

ClOO

281-0544-00

5.6pF,

Cer,

500V, 10%

C104

281-0544-00

5.6pF,

Cer,

500V,

10%

C106

283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C108

283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C120

283-0080-00

XB230000

0.022UF, Cer,

25V,

+80%-20%

C129

290-0134-00

22uF, Elect.

,

15V,

20%

C136

283-0080-00

0.022UF, Cer,

25V,

+80%-20%

C138

283-0079-00

O.OluF,

Cer,

250V, 20%

C141

281-0593-00

3.9pF, Cer,

500V, 10%

C147

281-0593-00

3.9pF, Cer,

500V, 10%

C150

281-0629-00

33pF,

Cer, 600V, 5%

C152

281-0543-00

270pF,

Cer,

500V,

10%

C156

281-0629-00

33pF, Cer,

600V, 5%

C170

281-0534-00

3.3pF, Cer,

500V,

+0.25pF

C171

281-0534-00

3.3pF, Cer,

500V,

+0.25pF

C173

283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C176

281-0552-00

25pF,

Cer,

500V

C178

283-0002-00

O.OluF,

Cer,

500V

C179

283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C198

283-0059-00

luF, Cer,

25V,

+80%-20%

C199

283-0059-00

luF,

Cer,

25V,

+80%-20%

C200

281-0511-00

22pF,

Cer,

500V, 10%

C201

283-0059-00

luF,

Cer,

25V,

+80%-20%

C203

281-0511-00

22pF,

Cer,

500V, 10%

C204

283-0059-00

luF, Cer,

25V,

+80%-20%

C207

283-0080-00

0.022UF,

Cer, 25V,

+80%-20%

C209

290-0267-00

luF,

Elect.

,

35V

C210

281-0523-00

lOOpF,

Cer,

350V, 20%

C212

281-0523-00

lOOpF,

Cer, 350V, 20%

C248

283-0010-00

0.05uF,

Cer, 50V

C255

283-0010-00

0.05uF,

Cer, 50V

C268

283-0604-00

304pF, Mica,

300V, 2%

REV. C NOV.

1974

6-3

Electrical

Parts

List-7B71

(SN

B205000-up)

Ckt.

No.

Tektronix

Part

No.

Serial/Model

Eff

No.

Disc

Description

CAPACITORS

(cont)

C275 281-0523-00

lOOpF,

Cer,

350V,

20%

C282 283-0002-00

O.OluF,

Cer,

500V

C303 283-0159-00

18pF,

Cer,

50V, 5%

C312 283-0080-00

0.022UF,

Cer,

25V,

+80%-20%

C315 283-0156-00

O.OOluF,

Cer,

200V, 10%

C319

283-0080-00

0.022UF,

Cer,

25V,

+80%-20%

C320 281-0662-00

lOpF,

Cer,

500V, lO.SpF

C324 283-0175-00

lOpF,

Cer,

200V, 5%

C331 283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C332 283-0159-00

18pF,

Cer, 50V, 5%

C336 283-0080-00

0.022UF, Cer,

25V,

+80%-20%

C339 290-0305-01

3uF, Elect.,

150V,

10%

C363 283-0059-00

luF,

Cer,

25V,

+80%-20%

C403 290-0523-00

2.2uF, Elect.,

20V, 20%

C405

290-0523-00

2.2uF, Elect.,

20V, 20%

C406 290-0523-00

2.2UF, Elect.,

20V, 20%

C409 290-0523-00

2.2uF,

Elec.t,

20V,

20%

DIODES

CR148 152-0153-00

Silicon,

FD7003 or

CD5574

CR149 152-0153-00

Silicon, FD7003

or CD5574

CR181 152-0322-00

Silicon,

A1108

CR182 152-0322-00

Silicon,

A1108

CR205

*

152-0322-00

Silicon,

A1108

CR210 152-0322-00

Silicon,

A1108

CR212

152-0322-00

Silicon, A1108

CR319

152-0322-00

Silicon,

A1108

CR320

152-0185-00

Silicon,

similar to 1N4152

CR331 152-0075-00

Germanium, GD238

or ED48

CR342

152-0185-00

Silicon,

similar to 1N4152

CR355

152-0185-00

Silicon,

similar to 1N4152

CR357 152-0185-00

Silicon, sinular

to 1N4152

RELAYS

K44

148-0034-00

Armature, dpdt,

15V

DC

K48

148-0034-00

Armature, dpdt,

15V DC

K138

148-0034-00

Armature,

dpdt,

15V DC

INDUCTORS

LlOO

108-0577-00

30nH

L104

108-0577-00

30nH

L140

108-0581-00

lOOnH

L141

108-0369-00

0.12uH

L146 108-0581-00

lOOnH

L147 108-0369-00

0.12UH

L148 108-0578-00

45nH

L149 108-0578-00

45nH

6-4

REV. B NOV. 1974

Electrical

Parts

List-7871

(SN

B20500Q-up)

Tektronix

Serial/Model

No.

Ckt.

No.

Port

No. Eff

Disc

INDUCTORS

(cont)

L170

108-0579-00

L171

108-0579-00

L304

108-0580-00

L310

108-0317-00

L318

108-0370-00

TRANSISTORS

Q107

151-0220-00

Silicon, PNP,

2N4122

Q108

151-0220-00

Silicon, PNP,

2N4122

QUO

151-0220-00

Silicon, PNP,

2N4122

Q116

151-0220-00

Silicon, PNP,

2N4122

QUO

151-0224-00

Silicon,

NPN, 2N3692

Q126

151-0224-00

Silicon,

NPN, 2N3692

Q131

151-0220-00

Silicon, PNP,

2N4122

Q134

151-0220-00

Silicon, PNP,

2N4122

Q150

151-0259-00

Silicon, NPN,

selected from

2N3563

Q156

151-0259-00

Silicon,

NPN, selected

from 2N3563

Q158

151-0198-00

Silicon, NPN,

MPS918

Q159

151-0198-00

Silicon,

NPN,

MPS918

Q161

151-0188-00

Silicon, PNP,

2N3906

Q168

151-0198-00

Silicon,

NPN,

MPS918

Q169

151-0198-00

Silicon, NPN, MPS918

Q170

151-0198-00

Silicon,

NPN, MPS918

Q171

151-0198-00

Silicon,

NPN, MPS918

Q181

151-0223-00

Silicon, 2N4275

Q182

151-0223-00

Silicon, NPN, 2N4275

Q220

151-0221-00

Silicon, PNP,

2N4258

Q221

151-0221-00

Silicon, PNP,

2N4258

Q224

151-0190-01

Silicon, NPN,

2N3904 or

TE3904

Q235

151-0221-00

Silicon, PNP,

2N4258

Q236

151-0221-00

Silicon, PNP, 2N4258

Q238

151-0190-01

Silicon, NPN, 2N3904

or

TE3904

Q248

151-1006-00

Silicon,

FET,

U1491, N channel

junction

Q255

151-1006-00

Silicon,

FET,

U1491, N

channel junction

Q309

151-0271-00

Silicon, PNP, SAB4113

Q317

151-0271-00

Silicon, PNP,

SAB4113

Q326

151-0190-02

Silicon,

NPN, 2N3904

Q328

151-0190-02

Silicon, NPN,

2N3904

Q331

151-0221-00

BOlOlOO B229999

Silicon, PNP,

2N4258

Q331

151-0369-00

B230000

Silicon,

PNP,

SKA6664

Q338

151-0190-01

Silicon,

NPN, 2N3904

or TE3904

Q339

151-0220-00

Silicon,

PNP, 2N4122

Q346

151-0220-00

Q348

151-0192-00

Q350

151-0220-00

Q360

151-0223-00

Silicon, PNP,

2N4122

Silicon,

NPN, selected

from MPS6521

Silicon,

PNP, 2N4122

Silicon, NPN, 2N4275

Description

120nH
120nH

90nH
15uH

0.14uH

REV.

C

NOV.

1974

Electrical Parts List-7871 (SN

B205000-up)

Tektronix

Serial/Model

No.

No.

Part

No.

Eff

Disc

Description

TRANSISTORS

(cont)

Q368

151-0223-00

Silicon,

NPN,

2N4275

Q377 151-0223-00

Silicon,

NPN,

2N4275

RESISTORS

R40 322-0215-00

R42 322-0215-00

R47 321-0068-00

R49

321-0068-00

RlOO

315-0560-00

RlOl 321-0072-00

R103 321-0072-00

R104

315-0560-00

R106

315-0470-00

RIO 7

321-0046-00

R108

315-0470-00

RllO

315-0820-00

Rill

321-0193-00

R112

323-0161-00

R113

321-0047-00

R114

323-0161-00

R116 315-0820-00
R117

321-0193-00

R119 321-0288-00

R120 321-0291-00

R121 311-0732-00

R122 321-0282-00

R124 315-0102-00
R126 321-0288-00

R127 321-0293-00

R128

321-0285-00

R129 315-0102-00

R130 315-0152-00

R132

315-0122-00

R133 315-0122-00

R135 315-0361-00
R136 315-0102-00

R141 323-0151-00

R142

315-0511-00

R143

321-0115-00

R144 321-0115-00

R145 315-0511-00

R147 323-0151-00

R148 315-0223-00
R149 315-0223-00
R150

315-0560-00

1.69K

ohm,

0.25W, 1%

1.69K

ohm,

0.25W, 1%

49.9

ohm,

0.125W, 1%

49.9

ohm,

0.125W, 1%

56

ohm,

0.25W, 5%

54.9

ohm,

0.125W, 1%

54.9

ohm,

0.125W,

1%

56

ohm,

0.25W, 5%

47

ohm,

0.25W, 5%

29.4

ohm, 0. 125W, 1%

47

ohm,

0.25W,

5%

82

ohm,

0.25W, 5%

IK ohm,

0.125W, 1%

464

ohm, 0.50W, 1%

30.1 ohm,

0.125W, 1%

464

ohm,

0.50W,

1%

82

ohm,

0.25W,

5%

IK

ohm,

0.125W, 1%

9.76K ohm,

0.125W, 1%

10. 5K

ohm, 0.125W, 1%

IK ohm

,

Var

8.45K

ohm,

0.125W,

1%

IK

ohm,

0.25W, 5%

9.76K

ohm,

0.125W,

1%

llK

ohm, 0.125W, 1%

9.09K

ohm, 0.125W, 1%

IK

ohm,

0.25W,

5%

1.5K

ohm,

(nominal value),

1.2K

ohm,

0. 25W, 5%

1.2K ohm,

0. 25W, 5%

360 ohm,

0.25W, 5%

IK

ohm, 0. 25W, 5%

365 ohm,

0.50W,

1%

510

ohm,

0.25W,

5%

154

ohm,

0.125W,

1%

154 ohm, 0.125W, 1%

510

ohm,

0.25W,

5%

365 ohm,

0.50W,

1%

22K

ohm,

0.25W,

5%

22K ohm,

0.25W, 5%

56

ohm, 0.25W,

5%

6-6

selected

REV.

B

NOV. 1974

Electrical

Parts

List—7B71 (SN

B205000-up)

(t.

No.

Tektronix

Part

No.

Serial/Mode

Eff

3SISTORS

(cont)

R152

321-0045-00

R153

323-0153-00

R154

321-0045-00

R155 311-0633-00

R156 315-0560-00
R157

315-0510-00

R158

315-0562-00

R159

315-0122-00

R160

315-0392-00

R163

315-0392-00

R165

315-0432-00

R166

315-0112-00

R167

315-0562-00

R170 321-0096-00
R171

321-0096-00

R173

315-0201-00

R175 307-0115-00
R176

321-0201-00

R177

307-0115-00

R178 315-0100-00

R179 315-0201-00
R181 315-0113-00

R182

315-0332-00

R201 315-0512-00
R203

315-0512-00

R205 315-0104-00

R209 315-0512-00

R210 315-0221-00

R212 315-0221-00

R214

315-0155-00

R215

315-0472-00

R217

315-0124-00

R219 315-0153-00

R221 315-0162-00

R225 307-0112-00
R230 315-0155-00

R231 315-0472-00

R233 315-0124-00

R234

315-0153-00

R235 315-0162-00

R239 307-0112-00

R241 315-0106-00

R243 315-0474-00
R244 315-0623-00
R246 315-0106-00

I

No.

Disc

Description

28.7

ohm,

0.125W, 1%

383

ohm,

0.50W,

1%

28.7

ohm,

0.125W, 1%

5K

ohm,

Var

56

ohm,

0.25W,

5%

51

ohm,

0.25W, 5%

5.6K

ohm,

0.25W, 5%

1.2K ohm,

0.25W,

5%

3.9K ohm,

0.25W, 5%

3.9K ohm,

0.25W, 5%

4.3K

ohm,

0.25W, 5%

l.lK

ohm,

0.25W, 5%

5.6K ohm,

0.25W, 5%

97.6

ohm,

0.125W, 1%

97.6

ohm,

0.125W, 1%

200

ohm,

0.25W, 5%

7.5

ohm, 0.

25W,

5%

1.21K ohm,

0.125W, 1%

7.5

ohm,

0.25W, 5%

10

ohm,

0.25W, 5%

200

ohm,

0.25W, 5%

llK

ohm,

0. 25W,

5%

3.3K ohm,

0.25W, 5%

5. IK

ohm,

0.25W, 5%

5. IK

ohm,

0. 25W,

5%

lOOK

ohm,

0.25W,

5%

5. IK ohm,

0.

25W,

5%

220

ohm,

0.25W, 5%

220

ohm,

0.25W,

5%

1.5M ohm,

0.25W, 5%

4.

7K ohm,

0.

25W, 5%

120K ohm,

0.25W, 5%

15K

ohm, 0.

25W,

5%

1. 6K

ohm,

0. 25W,

5%

4.3

ohm,

0.25W,

5%

1.5M ohm,

0.

25W, 5%

4.7K ohm,

0.25W, 5%

120K

ohm,

0.25W, 5%

15K

ohm.

0.

25W, 5%

1 . 6K

ohm

,

,

0

.25W

,

5%

4.3

ohm.

0.

25W, 5%

lOM

ohm.

0.

25W, 5%

470K ohm,

,

0

.25W

,

5%

62K ohm,

0.

25W, 5%

lOM

ohm.

0. 25W, 5%

REV.

B

NOV. 1974

6-7

Electrical

Parts

List-7B71

(SN

B205000-up)

Ckt.

No.

Tektronix

Part

No.

Serial/Model

No.

Eff

Disc

Description

RESISTORS

(cont)

R248

315-0510-00

R250

321-0240-00

R251

311-0884-00

R252

321-0222-00

R253

321-0260-00

R255

315-0510-00

R257

321-0240-00

R258

311-0884-00

R259

321-0222-00

R260

321-0260-00

R265

315-0102-00

R275

321-0289-00

R282

315-0102-00

R284

315-0123-00

R300

315-0620-00

R301

321-0158-00

R302

321-0135-00

R303

315-0430-00

R306

315-0620-00

R307

321-0177-00

R310

315-0471-00

R312

315-0100-00

R313

321-0201-00

R315

315-0200-00

R318

315-0151-00

R319

315-0752-00

R320

315-0751-00

R322

315-0391-00

R324

315-0301-00

R326

315-0200-00

R327

315-0242-00

R328

315-0152-00

R329

315-0200-00

R331

321-0161-00

R333

315-0102-00

R334

315-0183-00

R335

315-0202-00

R336

315-0102-00

R339

315-0471-00

R340

315-0102-00

R341

315-0303-00

R342

315-0102-00

R343

315-0154-00

R344

315-0223-00

R346

315-0302-00

51 ohm, 0.25W,

5%

3.09K ohm, 0.125W,

1%

100 ohm, Var

2K ohm, 0.125W,

1%

4.99K ohm, 0.125W,

1%

51 ohm, 0.25W,

5%

3.09K ohm, 0.125W,

1%

100 ohm, Var

2K ohm,

0.125W,

1%

4.99K ohm,

0.125W,

1%

IK ohm,

0. 25W,

5%

lOK ohm,

0.125W,

1%

IK ohm, 0.25W,

5%

12K ohm,

0.25W, 5%

62 ohm, 0.25W,

5%

432

ohm,

0.125W,

1%

249

ohm,

0.125W,

1%

43

ohm,

(nominal value)

,

selected

62

ohm, 0.25W,

5%

681

ohm,

0.125W,

1%

470

ohm,

0.25W,

5%

10 ohm,

0.25W,

5%

1.21K ohm,

0.125W,

1%

20 ohm,

0.25W,

5%

150 ohm,

0.25W,

5%

7.5K ohm,

0.25W,

5%

750 ohm,

0.25W,

5%

390 ohm,

0.25W,

5%

300

ohm, 0.25W,

5%

20 ohm,

0.25W,

5%

2.4K ohm,

0.25W, 5%

1. 5K ohm,

0. 25W,

5%

20 ohm,

0.25W,

5%

464 ohm,

0.125W,

1%

IK ohm,

0.

25W,

5%

18K ohm,

0.25W,

5%

2K ohm,

0.25W,

5%

IK

ohm, 0.25W,

5%

470 ohm,

0.25W,

5%

IK

ohm,

0.25W,

5%

30K ohm,

0.25W,

5%

IK ohm,

0.25W,

5%

150K ohm,

0.25W,

5%

22K ohm,

0.25W,

5%

3K

ohm,

0. 25W,

5%

6-8

REV.

C NOV.

1974

Electrical

Parts

List-7B71

(SN

B205000-up)

Ckt.

No.

Tektronix

Port

No.

Serial/Model

Eff

No.

Disc

Description

RESISTORS

(cont)

R353 321-0321-00

21. 5K

ohm,

0.125W, 1%

R354

321-0285-00

9.09K

ohm,

0.125W,

1%

R356

321-0177-00

681

ohm,

0.125W, 1%

R357

321-0239-00

3. OIK

ohm,

0.125W, 1%

R361

321-0126-00

200

ohm,

0.125W,

1%

R363

307-0111-00

3.6 ohm,

0.25W, 5%

R364 321-0144-00

309

ohm,

0.125W, 1%

R366

321-0122-00

182

ohm,

0.125W, 1%

R367

321-0030-00

20

ohm,

0.125W, 1%

R370

323-0192-00

976

ohm,

0.50W, 1%

R374

315-0101-00

100

ohm,

0.25W,

5%

R377

315-0391-00

390

ohm,

0.25W,

5%

R379

315-0182-00

1.8K ohm,

0.25W, 5%

R380

315-0100-00

10 ohm,

0.25W,

5%

R401

307-0106-00

4.7

ohm,

0.25W, 5%

R402

307-0106-00

4.7

ohm,

0.25W,

5%

R403

307-0106-00

4.7

ohm,

0.25W, 5%

INTEGRATED CIRCUITS

U260

156-0049-00

Operational

amplifier,

uA741C

U267

156-0049-00

Operational

amplifier,

uA74lC

DIODES, ZENER

VR304

152-0140-01

Tunnel,

10mA,

8pF

VR322

152-0125-00

Tunnel,

TD3A,

4.7mA,

Tek

Spec

VR358 152-0125-00

Tunnel,

TD3A,

4.7mA, Tek

Spec

670-1142-03

INTERFACE

Circuit Board

Assembly

CAPACITORS

C280

290-0267-00

C530P 281-0523-00

C530R

281-0536-00

C530S 283-0599-00

C584

290-0136-00

DIODES

CR44

152-0185-00

Silicon,

similar

to 1N4152

CR461

152-0185-00

Silicon,

similar

to 1N4152

CR531

152-0185-00

Silicon,

similar

to 1N4152

CR702

152-0075-00

Germani\am,

GD238

or ED48

CR703

152-0185-00

Silicon,

similar

to

1N4152

CR704

152-0185-00

Silicon,

similar

to

1N4152

CR705

152-0185-00

Silicon,

similar

to 1N4152

CR711

152-0185-00

Silicon,

similar

to 1N4152

CR712

152-0185-00

Silicon,

similar

to 1N4152

luF,

Elect.

,

35V

lOOpF,

Cer, 350V,

20%

lOOOpF,

Cer,

500V, 10%

98pF, Mica,

500V, 5%

2.2uF, Elect.,

20V, 20%

REV.

C

NOV. 1974

6-9

Electrical

Parts

List-7B71

(SN

B205000-up)

Ckt.

No.

DIODES

(cont)

CR721

CR722

SWITCHES

S530^

S5312

RESISTORS

R280

R347
R460

R461

R530A
R530B

R530C

R530D
R530F

R530H

R530J
R530K

R530L

R530M

R530N
R530P

R530R

R530S

R531
R584
R701

R702

R704
R705

R706
R711

R712

R713
R715

R721

R722
R723

R724

R727
R728
R729

R830

Tektronix

Part

No.

152-0185-00
152-0185-00

670-1142-03

315-0513-00

315-0200-00

315-0472-00

315-0752-00

323-0568-08

323-0557-08

323-0546-08

323-0546-08

323-0767-07

323-0450-07

323-0450-07

323-0774-07

323-0354-07
321-0267-00

323-0775-07

315-0330-00
315-0220-00

315-0390-00

311-0959-00

315-0101-00

315-0154-00

315-0133-00

315-0154-00

321-0344-00

315-0753-00

315-0753-00

315-0154-00

315-0753-00

315-0154-00

315-0753-00

315-0154-00

315-0154-00

321-0356-00

321-0335-00
321-0344-00
315-0154-00

315-0160-00

Serial/Model

No.

Eff

Disc

^See Mechanical

Parts

List for

replacement

parts.

Furnished

as a unit

with

S530.

Description

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Cam

TIME/DIV

CAL

IN

51k

ohm,

0.25W, 5%

20 ohm,

0.25W, 5%

4.7K

ohm,

0.25W, 5%

7.5K

ohm,

0.25W, 5%

8.06M ohm,

0.50W, 1%

6.19M

ohm,

0.50W, 1%

4.75

m ohm,

0.50W,

1%

4.75M

ohm,

0.50W, 1%

1.425M ohm,

0.50W, 0.1%

475K

ohm,

0.50W,

0.1%

475K ohm,

0.50W, 0.1%

118.

7K ohm, 0.50W, 0.1%

47.

5K ohm,

0.50W, 0.1%

5.9K ohm,

0.125W, 1%

71.25K ohm,

0.50W, 0.1%

33

ohm,

0.25W,

5%

22

ohm,

0.25W,

5%

39

ohm, 0.25W, 5%

lOK

ohm,

Var

100 ohm,

0.25W, 5%

150K ohm,

0.25W, 5%

13K ohm,

0.25W, 5%

150K

ohm,

0.25W,

5%

37. 4K

ohm,

0.125W,

1%

75K ohm,

0.25W, 5%

75K ohm,

0. 25W, 5%

150K

ohm, 0.25W, 5%

75K

ohm, 0.25W, 5%

150K

ohm,

0.25W, 5%

75K ohm,

0.25W, 5%

150K

ohm,

0.25W,

5%

150K ohm, 0.25W, 5%

49.

9K

ohm, 0.125W, 1%

30. IK

ohm,

0.125W,

1%

37.

4K ohm,

0.125W, 1%

150K ohm,

0.25W,

5%

16

ohm, 0.25W, 5%

6-10

REV B NOV. 1974

Ckt.

No.

Tektronix

Part

No.

Serial/Modei

No.

Eff

Disc

Electrical Parts

List-7B71

(SN

B205000-up)

Description

670-1143-02

TRIGGER

MODE

Circuit

Board

Assembly

BULBS

DS274

150-0048-01

Incandescent

#683, selected

DS446

150-0048-01

Incandescent

#683,

selected

RESISTORS

R264

321-0338-00

32.

4K

ohm,

0.125W, 1%

R273

321-0305-00

14.

7K

ohm,

0.125W, 1%

SWITCH

S273^

670-1143-02

Pushbutton,

KOBE

670-1146-02

COUPLING

Circuit

Board

Assembly

BULB

DS270

150-0048-01

Incandescent

#683,

selected

CAPACITOR

C270

283-0026-00

0.2uF,

Cer,

25V

RESISTOR

R271

321-0325-00

23.

7K

ohm,

0.125W, 1%

SWITCH

S270^ 670-1146-02

Pushbutton

,

COUPLING

670-1169-05

TIME

BASE

Circuit

Board

Assembly

CAPACITORS

C404 283-0080-00

0.022UF,

Cer,

25V, +80%-20%

C407

283-0080-00

0.022UF, Cer,

25V, +80%-20%

C421

283-0080-00

0.022UF,

Cer,

25V, +80%-20%

C431

283-0080-00

0.022UF,

Cer,

25V, +80%-20%

C434

281-0577-00

14pF, Cer,

500V,

5%

C441

283-0080-00

0.022UF,

Cer,

25V, +80%-20%

c446

290-0136-00

2.2uF, Elect.,

20V, 20%

C456 290-0136-00

2.2uF,

Elect.,

20V,

20%

C457 281-0524-00

150pF,

Cer,

500V,

20%

C466

283-0080-00

0.022UF,

Cer,

25V,

+80%-20%

C469

283-0000-00

O.OOluF,

Cer,

500V,

+100%-0%

C488

290-0136-00

2.2uF,

Elect.,

20V, 20%

C497 290-0136-00

2.2uF,

Elect.,

20V,

20%

C499 290-0136-00

2.2uF,

Elect.,

20V, 20%

C501

290-0134-00

22uF,

Elect.,

15V, 20%

C520

281-0603-00

39pF,

Cer,

500V, 5%

C524

281-0524-00

150pF,

Cer,

500V, 20%

^See

Mechanical

Parts

List

for

replacement

parts.

REV. B

NOV.

1974

6-11

Electrical

Parts

List-7B71 (SN

B205000-up)

Serial/Modei

No.

Eff

Disc

Description

lOOpF,

Cer, 350V,

20%

5.5-19pF, Var, Cer

82pF,

Cer,

lOOOV, 5%

2-8pF, Var, Cer

13pF, Cer, 500V,

2%

0.022UF, Cer, 25V,

+80%-20%

2.2uF, Elect., 20V,

20%

7-25pF, Var, Cer, 350V

2.2uF, Elect., 20V,

20%

C551

281-0523-00

lOOpF, Cer, 350V,

20%

C556

281-0552-00

25pF, Cer, 500V

C561

290-0136-00

2.2uF, Elect., 20V,

20%

C580A

283-0164-00

2.2uF, Cer, 25V,

20%

C580B

283-0191-00

0.022uF, Cer, 50V,

20%

C580D

283-0666-00

890pF, Mica, lOOV,

2%

C583

283-0080-00

0.022UF, Cer,

25V,

+80%-20%

C591

281-0523-00

lOOpF, Cer, 350V,

20%

C592

281-0546-00

330pF, Cer, 500V,

10%

C746

283-0191-00

0.022UF, Cer, 50V,

20%

C748

283-0191-00

0.022UF, Cer, 50V,

20%

C752

281-0562-00

39pF, Cer, 500V

C780

281-0508-00

12pF,

Cer, 500V,

20%

C787

281-0549-00

68pF, Cer, 500V,

10%

C788

290-0527-00

15uF, Elect.

,

20V,

20%

C789

283-0067-00

O.OOluF,

Cer, 200V,

10%

C799

290-0136-00 2.2uF, Elect.,

20V,

20%

C801

290-0420-00 0.68UF, Elect.,

75V,

20%

C803

290-0136-00 2.2uF, Elect., 20V,

20%

C805

290-0529-00 47uF, Elect.,

20V,

20%

C807

290-0136-00 2.2uF,

Elect., 20V,

20%

C809

283-0080-00 0.022UF, Cer, 25V,

+80%-20%

C813

290-0136-00 2.2uF,

Elect., 20V,

20%

C815

290-0136-00 2.2uF,

Elect., 20V,

20%

C817

290-0136-00 2.2uF,

Elect., 20V,

20%

C819

290-0136-00 2.2uF,

Elect., 20V,

20%

C821

290-0420-00 0.68UF,

Elect., 75V,

20%

DIODES

CR406

152-0185-00 Silicon,

similar to

1N4152

CR412

152-0185-00 Silicon,

similar to

1N4152

CR413

152-0185-00 Silicon,

similar to 1N4152

CR414

152-0185-00 Silicon, similar

to 1N4152

CR419

152-0185-00

Silicon,

similar to

1N4152

CR427

152-0185-00

Silicon,

similar to

1N4152

CR428

152-0185-00 Silicon,

similar to 1N4152

CR431

152-0185-00

Silicon,

similar to 1N4152

Tektronix

Ckt.

No. Part

No.

CAPACITORS (cent)

C527

281-0523-00

C530J

281-0093-00

C530K

283-0126-00

C530L

281-0091-00

C530M

281-0657-00

C532

283-0080-00

C536

290-0136-00

C537

281-0160-00

C545

290-0136-00

6-12

REV. B NOV.

1974

Electrical

Parts List-7B71

(SN

B205000-up)

Ckt.

No.

DIODES

(cont)

CR436

CR446

CR448

CR449

CR451

CR452

CR453

CR454
CR459

CR462
CR463

CR464

CR465

CR466

CR467

CR468

CR469

CR472

CR493

CR494

CR498

CR512

CR516

CR520

CR526

CR528

CR529

CR548

CR571

CR572

CR574

CR575
CR576

CR580
CR581

CR582

CR596

CR598

RELAY

K780

INDUCTOR

L520
L593

Tektronix

Port

No.

152-0185-00
152-0185-00
152-0185-00
152-0185-00
152-0185-00
152-0185-00
152-0185-00

152-0185-00

152-0185-00

152-0185-00
152-0185-00
152-0185-00

152-0185-00
152-0185-00

152-0185-00
152-0185-00
152-0185-00
152-0185-00

152-0185-00
152-0185-00
152-0185-00

152-0322-00

152-0322-00

152-0141-02

152-0185-00
152-0185-00

152-0246-00

152-0141-02

152-0185-00

152-0185-00

152-0185-00
152-0185-00
152-0185-00

152-0185-00
152-0185-00
152-0185-00
152-0307-00

152-0185-00

148-0034-00

276-0507-00
108-0440-00

Serial/Model

No.

Eff

Disc

XB220000

REV. B NOV.

1974

_

Description

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

A1108

Silicon,

A1108

Silicon,

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

CD126T6

or FD3375

Silicon,

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to 1N4152

Silicon,

similar

to

1N4152

Silicon,

similar

to

1N4152

Silicon,

MSD6100,

dual

Silicon,

similar

to

1N4152

Armature,

dpdt,

15V DC

Core,

ferramic

suppressor

8uH

6-13

Electrical

Parts

List-7871

(SN

B205000-up)

Ckt.

No.

TRANSISTORS

Q402

Q404
Q406

Q408

Q410

Q416
Q424

Q432

Q436

Q442
Q446
Q454

Q456
Q468

Q472

Q482
Q492
Q496

Q510A,B

Q520A,B

Q526

Q532A,B

Q533

Q534
Q537
Q546
Q554

Q564
Q566

Q582

Q592A,B

Q594

Q784

Q794

RESISTORS

R400

R402

R403

R404
R405

R406

R407

R408

R409
R410

Tektronix

Serial/Model

No.

Part

No.

Eff

Disc

151-0188-00
151-0188-00
151-0190-01
151-0190-01
151-0188-00

151-0190-01

151-0190-01
151-0188-00

151-0188-00

151-0188-00

151-0207-00

151-0190-01

151-0190-01

151-0190-01

151-0188-00
151-0190-01
151-0190-01
151-0190-01

151-0261-00

151-1036-00

151-0289-00

151-1036-00
151-0198-00
151-0325-00

151-0190-01
151-0220-00
151-0190-01

151-0190-01

151-0190-01

151-0188-00

151-0232-00
151-0333-00

151-0325-00

151-0325-00

315-0101-00
315-0751-00
315-0101-00

315-0151-00

315-0332-00

315-0103-00

315-0151-00
321-0174-00
321-0246-00

315-0101-00

Description

Silicon,

PNP,

2N3906

Silicon,

PNP,

2N3906

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

PNP,

2N3906

Silicon

,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

PNP,

2N3906

Silicon,

PNP,

2N3906

Silicon,

PNP,

2N3906

Silicon,

NPN,

2N3415

Silicon

,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

PNP,

2N3906

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

PNP,

NS7406,

dual

Silicon,

FET

,

FD1551,

dual

Silicon,

PNP,

MM999

Silicon,

FET, FD1551,

dual

Silicon,

MPS918

Silicon,

PNP,

2N4258

Silicon

NPN, :

2N3904

or TE3904

Silicon,

PNP,

2N4122

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN,

2N3904

or TE3904

Silicon,

NPN, 2N3904

or TE3904

Silicon,

PNP,

2N3906

Silicon,

NPN,

2N2919, dual

Silicon,

NPN,

selected from

MPS918

Silicon,

PNP,

2N4258

Silicon,

PNP,

2N4258

100

ohm,

0.25W, 5%

750

ohm,

0.25W, 5%

100

ohm,

0.25W, 5%

150

ohm,

0.25W, 5%

3.3K

ohm, 0.25W, 5%

lOK

ohm,

0.25W, 5%

150

ohm,

0.25W,

5%

634

ohm,

0.125W, 1%

3.57K ohm,

0.125W,

1%

100

ohm,

0.25W, 5%

6-14 REV

C NOV. 1974

Electrical Parts List—7B71

(SN B205000-up)

Ckt.

No.

Tektronix

Port

No.

Serial/Model

No.

Eff

Disc

Description

7.5K

ohm,

0.125W, 1%

15K ohm,

0.25W, 5%

18. 7K

ohm,

0.125W, 1%

2K

ohm,

0.125W, 1%

220

ohm,

0.25W, 5%

430

ohm,

0.25W, 5%

l.lK

ohm,

0.25W,

5%

PESISTORS

(cont)

R411 321-0277-00

R412 315-0153-00

R416 321-0315-00

R418

321-0222-00

R419 315-0221-00

R421 315-0431-00

R422 315-0112-00
R423 315-0220-00

R424

315-0302-00

R426

315-0132-00

R427

315-0561-00

R428 321-0300-00

R431 315-0470-00

R432

321-0136-00

R433 321-0129-00
R434 321-0265-00

R435 321-0244-00
R436 321-0167-00

R438 301-0102-00

R441

301-0470-00

R444

315-0102-00

R448 321-0277-00
R449 315-0472-00

R451 315-0223-00

R452 315-0153-00

R454

315-0472-00

R455 315-0682-00

R456 315-0153-00

R458 315-0103-00
R459 315-0123-00

R462 315-0752-00

R464 321-0271-00
R465 321-0234-00
R466 321-0277-00

R468

321-0306-00

R469 321-0209-00

R471 321-0271-00

R472 321-0193-00

R474

321-0150-00

R475 321-0215-00

R477 321-0219-00

R482 321-0139-00

R484 321-0241-00
R485 321-0196-00
R488 315-0101-00

22

ohm,

0.25W,

5%

3K ohm,

0.25W, 5%

1.3K

ohm,

0.25W, 5%

560

ohm,

0.25W, 5%

13K ohm,

0.125W, 1%

47

ohm,

0.25W, 5%

255

ohm,

0.125W, 1%

215

ohm,

0.125W, 1%

5.62

k ohm,

0.125W, 1%

3.4K

ohm,

0.125W, 1%

536 ohm,

0.125W,

1%

IK

ohm,

0.50W, 5%

47

ohm,

0.50W, 5%

IK

ohm,

0.

25W,

5%

7.5k ohm,

0.125W, 1%

4.7K ohm,

0.25W, 5%

22K ohm,

0.25W, 5%

15K ohm,

0.25W, 5%

4.7K

ohm,

0.25W, 5%

6.8K

ohm,

0.25W, 5%

15K ohm,

0.

25W,

5%

lOK

ohm,

0.25W,

5%

12K

ohm,

0.25W, 5%

7.5K ohm,

0.25W, 5%

6.49K ohm,

0.125W, 1%

2.67K ohm,

0.125W, 1%

7.5k

ohm,

0.125W, 1%

15K

ohm,

0.125W, 1%

1.47K ohm,

0.125W,

1%

6.49K ohm,

0.125W,

1%

IK

ohm,

0.125W, 1%

357

ohm,

0.125W, 1%

1.69K ohm,

0.125W, 1%

1.87K

ohm,

0.125W, 1%

274

ohm,

0.125W, 1%

3.16K ohm,

0.125W,

1%

1.07K

ohm,

0.125W, 1%

100

ohm,

0.25W,

5%

REV.

B NOV. 1974

6-15

Electrical

Parts

List-7871

(SN B205000-up)

Description

1.27K ohm, 0.125W, 1%

240

ohm, 0.25W, 5%

2K

ohm, 0.125W, 1%

1.27K ohm,

0.125W,

1%

1.5k ohm,

0.50W, 5%

330

ohm, 0.25W, 5%

47

ohm, 0.25W, 5%

330

ohm, 0.25W, 5%

lOK

ohm, Var

R501

321-0399-00

140K ohm,

0.125W,

1%

R503

321-0407-00

169K ohm,

0.125W,

1%

R511

321-0203-00

1.27K ohm, 0.125W, 1%

R515

322-0261-00

5.11k ohm,

0.25W,

1%

R517

321-0203-00

1.27K ohm, 0.125W, 1%

R520

315-0203-00

20K

ohm, 0.25W,

5%

R521

321-0299-00

12. 7K

ohm, 0.125W, 1%

R523

321-0264-00

5.49K ohm, 0.125W, 1%

R524

315-0222-00

2.2K ohm, 0.25W, 5%

R526

321-0269-00

6.19K ohm,

0.125W,

1%

R527

321-0193-00

IK ohm, 0.125W, 1%

R532

315-0122-00

1. 2K ohm,

0.

25W, 5%

R533

321-0219-00

1.87K ohm, 0.125W,

1%

R534

322-0281-00

8.25K ohm, 0.25W, 1%

R536

315-0220-00

22

ohm, 0.25W,

5%

R537

315-0681-00

680

ohm, 0.25W,

5%

R538

315-0330-00

33 ohm, 0.25W,

5%

R539

315-0101-00

100 ohm, 0.25W, 5%

R540

315-0622-00

6.2K

ohm, 0.25W,

5%

R541

315-0131-00

130 ohm, 0.25W,

5%

R542

321-0259-00

4.87K ohm, 0.125W, 1%

R543 Selected

R544

321-0231-00

2.49K ohm,

0.125W,

1%

R545

315-0470-00

47

ohm, 0.25W,

5%

R546

301-0102-00

IK ohm, 0.50W, 5%

R547

315-0183-00

18K ohm,

0.25W, 5%

R548

301-0561-00

560 ohm, 0.50W,

5%

R549

315-0472-00

4. 7K ohm, 0.

25W,

5%

R551

321-0211-00

1.54K ohm,

0.125W,

1%

R552

321-0231-00

2.49K

ohm, 0.125W,

1%

R554

321-0178-00

698

ohm,

0.125W, 1%

R556

321-0260-00

4.99K ohm, 0.125W,

1%

R557

321-0239-00

3. OIK ohm, 0.125W,

1%

R558

321-0193-00

IK ohm, 0.125W,

1%

R561

315-0820-00

82

ohm, 0.25W,

5%

R564

321-0207-00

1.4K ohm, 0.125W,

1%

RESISTORS

(cont)

R489
R493

R494

R495

R496

R497

R498

Tektronix

Port

No.

321-0203-00

315-0241-00

321-0222-00

321-0203-00

301-0152-00

315-0331-00
315-0470-00
315-0331-00
311-1268-00

6-16

REV. B

NOV. 1974

Electrical Parts

List-7B71 (SN

B205000-up)

Ckf.

No.

Tektronix

Part

No.

Serial/Model

No.

Eff

Disc

Description

RESISTORS

(cont)

R565

315-0911-00

R566

315-0101-00

R567

301-0162-00

R568 315-0470-00

R573

321-0295-00

R580C

323-0222-00

R581 315-0223-00

R582

323-0289-00

R583 315-0104-00

R590

311-1268-00

R591 321-0277-00

R592 321-0147-00

R593 315-0201-00

R594

322-0273-00

R595 315-0200-00
R596 322-0310-00

R599

322-0297-00

R745 315-0220-00

R746

321-0260-00

R747

315-0220-00

R748

315-0114-00

R755 321-0279-00

R767

321-0222-00

R775

321-0152-00

R776 321-0204-00
R777 321-0191-00

R778 315-0752-00

R780 315-0201-00

R781 323-0272-00

R782 321-0735-07

R783

315-0752-00

R784 321-0228-00
R785 311-1221-00
R786 321-0088-09

R787

315-0472-00

R788 315-0472-00

R789 315-0472-00
R790 315-0433-00

R791 323-0272-00
R794 321-0228-00
R795 311-1230-00
R796

321-0289-00

R797

321-0289-00

R798

315-0510-00

R799

315-0101-00

910

ohm,

0.25W,

5%

100

ohm,

0.25W, 5%

I.

6K ohm,

0.50W, 5%

47

ohm,

0.25W,

5%

II. 5K

ohm,

0.125W, 1%

2K ohm,

0.50W, 1%

22K

ohm,

0.25W, 5%

lOK

ohm,

0.50W, 1%

lOOK

ohm,

0.25W,

5%

lOK

ohm,

Var

7.5K

ohm,

0.125W, 1%

332

ohm,

0.125W,

1%

200

ohm,

0.25W, 5%

6.81K

ohm,

0.25W, 1%

20

ohm,

0.25W, 5%

16.

5K

ohm,

0.25W, 1%

12. IK

ohm,

0.25W, 1%

22

ohm,

0.25W, 5%

4.99K ohm,

0.125W, 1%

22

ohm,

0.25W, 5%

IlOK

ohm,

0.25W, 5%

7.87

k ohm,

0.125W, 1%

2K ohm,

0.125W, 1%

374

ohm,

0.125W, 1%

1.3K

ohm,

0.125W, 1%

953

ohm,

0.125W, 1%

7.5K

ohm,

0.25W,

5%

200

ohm,

0.25W, 5%

6.65K ohm,

0.50W, 1%

I.OOIK

ohm,

0.125W,

0.1%

7.5K ohm,

0.25W,

5%

2.32K

ohm,

0.125W, 1%

50

ohm,

Var

80.6

ohm,

0.125W, 1%

4.7K ohm,

0.25W,

5%

4.7K

ohm,

0.25W, 5%

4.

7K

ohm,

0.

25W, 5%

43K

ohm,

0.25W,

5%

6.65K

ohm,

0.50W, 1%

2.32K

ohm,

0.125W, 1%

20K

ohm,

Var

lOK

ohm,

0.125W, 1%

lOK

ohm,

0.125W, 1%

51

ohm,

0.25W, 5%

100

ohm,

0.25W, 5%

REV.

B NOV.

1974

6-17

Electrical

Parts

List-7B71

(SN

B205000-up)

Ckt.

No.

Tektronix

Part

No.

Serial/Model

Eff

No.

Disc

Description

RESISTORS

(cont)

R801

315-0510-00

51

ohm,

0.25W, 5%

R803

315-0470-00

47

ohm,

0.25W,

5%

R804 315-0623-00

62K ohm,

0.25W, 5%

R805

315-0470-00

47

ohm,

0.25W,

5%

R807

315-0101-00

100

ohm,

0.25W, 5%

R809

315-0101-00

100

ohm,

0.25W, 5%

R815 315-0470-00

47

ohm,

0.25W, 5%

R817

315-0910-00

91

ohm,

0.25W, 5%

R819

315-0101-00

100

ohm,

0.25W,

5%

R821

315-0510-00

51

ohm,

0.25W, 5%

INTEGRATED

CIRCUIT

U752

156-0049-00

Operational

amplifier,

UA741C

DIODES

,

ZENER

VR573 152-0279-00

Zener,

1N751A,

0.4W,

5.1V, 5%

VR576 152-0326-00

Zener,

1N755A, 0.4W,

7.5V,

5%

670-1103-02

B

DELAY

MODE Circuit

Board

Assembly

BULB

DS490

150-0048-01

Incandescent

#683,

selected

RESISTORS

R490A

315-0820-00

82 ohm,

0.25W, 5%

R490B 315-0201-00

200

ohm,

0.25W, 5%

SWITCH

S490l

670-1103-02

Pushbutton,

B DELAY

MODE

670-1145-02

SOURCE

Circuit Board

Assembly

BULB

DS280

150-0048-01

Incandescent

#683,

selected

SWITCH

S2801

670-1145-02

Pushbutton,

SOURCE

670-1107-02

MAGNIFIER

Circuit

Board Assembly

BULB

DS780 150-0048-01

Incandescent

#683,

selected

SWITCH

S780^

670-1107-02

Pushbutton,

MAGNIFIER

1

See Mechanical Parts List for

replacement parts.

6-18

jREV.

C

NOV.

1974

SECTION 7

DIAGRAMS AND

MECHANICAL

PARTS

ILLUSTRATIONS

Symbols and Reference

Designators

Electrical

components shown on the diagrams

are in the following units unless noted otherwise:

Capacitors

=

Values one

or greater are

in picofarads (pF).

Values less than one are in microfarads

(/uF).

Resistors

=

Ohms

{Q.)

Symbols

used on the diagrams are based on USA Standard Y32.

2-1967.

Logic

symbology is

based

on MiL-STD-806B in terms

of

positive logic. Logic symbols

depict

the

logic function performed

and may

differ from

the manufacturer's data.

The following special symbols are used on the diagrams:

o

External

Screwdriver adjustment.

External control or connector.

Clockwise control rotation in direction of arrow.

Refer

to

diagram

number indicated in diamond.

Connection soldered to circuit board.

Connection made

to

circuit board with

interconnecting pin.

Pi^Cl'dibcuit boarct

Blue

tint encloses components located

on circuit board.

The

following prefix letters

are

used as reference designators to identify components or assemblies on the diagrams.

A Assembly, separable or repairable (circuit board, etc.)

LR Inductor/resistor combination

AT Attenuator, fixed or variable

M Meter

B

Motor

Q

Transistor or silicon-controlled rectifier

BT

Battery

P

Connector,

movable portion

C

Capacitor, fixed or

variable

R

Resistor, fixed or variable

CR

Diode,

signal or rectifier

RT Thermistor

DL

Delay

line

S

Switch

DS Indicating device (lamp)

T T

ransformer

F Fuse

TP

Test

point

FL Filter

U

Assembly, inseparable or non-repairable (integrated

H Heat

dissipating device

(heat

sink,

heat radiator,

etc.)

circuit,

etc.)

HR

Heater

V Electron tube

J Connector, stationary portion

VR Voltage regulator (zener

diode, etc.)

K Relay

Y

Crystal

L Inductor, fixed

or variable

BLOCK

DIAGRAM

EXT TRIG,

IN

OR

E.XT

VOLTS iN

TRlOGtR

SIGNAL

DELAY

MOD6.

CONTROL

EXT SINGLE

SWEEP RESET

SWEEP

)NHlfc\T

373

7B71 PLUG'IM

IS

BLOCK

DIAGRAM

BLOCK

DIAGRAM

VOLTAGE

AND WAVEFORM TEST

CONDITIONS

Typical voltage

measurements

were obtained under

the

following

conditions unless

noted otherwise on

the individual

diagrams.

Oscilloscope

Vertical

Mode

Left

Horizontal Mode

A

A Intensity

Optimum

7B70 (A

Horiz

Plug-In)

Level/Slope

Centered on positive slope

Triggering

Mode

P-P

Auto

Coupling

AC

Source

Ext

Magnifier

XI

Time/Div

1 ms

Variable Time/Div

Cal In

Display Mode

Time

Base

Position

Centered

7A16A (Left Vertical Plug-In)

Polarity

-i-UP

Bandwidth

20 MHz

Volts/Div

1 V

Coupling

AC

Position

Centered

7B71 (B Horiz Plug-In)

LEVEL/SLOPE

Centered

on positive slope

TRIGGERING

MODE

P-P

AUTO

COUPLING

AC

SOURCE

EXT

MAGNIFIER

XI

TIME/DIV

1 ms

B DELAY MODE

INDEPENDENT

DELAY TIME

MULTIPLIER

0.00

POSITION

Centered

VARIABLE TIME/DIV

CAL IN

The following

control

settings and connections

were changed to obtain waveform

photographs.

7B70

Time/Div

As

shown on waveforms

7A16A

Volts/Div

As shown

on waveforms

Signal input:

A one volt, one

kilohertz sine-wave applied

to both the 7B70 and

7B71

EXT

TRIG IN connector.

All

voltages given

on the diagrams are

in

volts.

Voltages

taken using a Fairchild

Model 7050 non-loading

digital multimeter.

Waveforms shown

are actual

waveform photographs

taken with

a

Tektronix

Oscilloscope

Camera System and Projected

Graticule.

Voltages and

waveforms

on the diagrams {shown in blue)

are not

absolute and may vary

between instruments

because

of differing

component

tolerances, internal

calibration or front

panel control

settings.

COUPLINS

(.%270)

1

I

SOURCE

(S280)

Kt3S

<§>

RZ8Z

K48

<i>

K44

<S>

FRONT PANEL

SWITCHES

e>*2.0SOOO-UP

<l>

!VLB

73

7B71

PLUG-IN

0

FRONT

PANEL

SWITCHES

TIME-BASE

GENERATOR

-fsov

»

^

y~

(TPJ

+50V

*-

^

f

R80I

i

,

51

1

Vv\

•

C80I

{TP)
+ i.SV

HSV-..

>

tL (

-

5ov-»

—

^

(TP)

-50V

tL

C82I

I

R82I

_-j'

wv-

I,

X:!

xt-OAP-Zj

+

50V

(DCPL)

aSV <^>

-'5V

^

,

l.DCPJ*l)

-I5V

Ctp)

+

IBV

A

3a<

37<i—

3«,<

3S<

33<

32^

31

<

30^—

(TP>

-15V

>-

^Cl'

vH

-I5V

'

R40I

4.T

4

—VW-

CI»9B|

r

C-406

2

R4-02,

l_-

3

vvv—

-

C^09

Z.ZfJLF

<s>

(TP)

+

5V

r>>-

--f-^V

t

+

SV

'<!>

(DCPl*E)

(dIpL»'

3)#

-iSV

<l>

<$’<$>

“50V

/2\

I

"(DCPl-)^

p-avR.“T\A-u TR\G,CS^£.R

&OARC

29^

28<

27<

26<

25<

24<

23<

22<

(0CPL1»2)

iK

I6<

15^

:

I3<

I2<

(

n|

lof-

9

<r

3

<-

2

<-

I

<-

T

COL-UMKI

CURREMT<^

WORD

SCAM^

LINES

X/

+ AUX

TRIG

^

+TRIG II

(DCPLtfc^l)

<s>

^TO

K48B

lei

-1-

ISV

'<£>

StNOLE

SWLLP

MODE

<^<§>

FROM

R46I

•LIGHTS

COMMON

6<

^

S

<

4<

-+S1G

FROM

QT8A<^

EXT

-READY

INDICATOR

<g>

FROM

RAA]

”

A

SV

lights

+5V

<^ROW CURRENT

-

WORD

SCAN

LINES

-AUX

TRIG

TR.C

TO

-50V

•

-

ISV

ext

single

/\

SWP

RESET

<^>

TO CR

451

^

SI&

FROM

QT94<^

DELAY

GATEa-

FROM

R49S ^

SWEEP

IKJHIBIT^

TO Q4IO

SAWTOOTH

OUT

FROM

qS46

^UIKIE

TRIGGER

SIG^^

TO

R280

A

SWP

houd-off

out

FROM R56S

.SWEEP

GATE^

FROM Q377 ^

DELAY

COKIT ROL

FROM

S490

DELAY

MODE

CONTROL^

TO

CR

3Sf

B

>3S

->37

>36

>3S

>3A

—

>33

-^32

>31

>30

>29
>28

>27

>26

>2S

>24
>23
>22

—

>21

>20

-^19

>

18

<s>

FAR.T1AU

^^iTS.^3.FAC_L

^sOAva^O

TBTl

PLUL-\N

REV. C,

APR.

1975

de;coupl_injg

^

OUTPUT

CONJMEIC

SKI fctOSOOO

-

UP

O R

DECOUPLING

&

OUTPUT

CONNECTOR