Bk Precision 1405, 1403A User Manual

v

SMHz

OSCILLOSCOPE

f

{t

K'

IEST

INSTRUTUENT

SAFETY

WARNIilG

\,

Normal amount exposed through the should eertain

more easily

praetiees away

eantly

1, High

2.

3. If

use of test equipment of

high voltage

be eonsidered

eonditions.

thCt

from

reduee the

voltage up to 1r400 high voltage that

a

anode

and removing

Dontt

sary.

Diseharge

possible,

high voltage points

and servieing

danger from eleetrieal

present.

is

heart

produee

your

high

expose

in defeetive

will stop

dangerous and

Higher

iethal eurrent.

a

prevent

will

nealt

eap.

power.

Turn

high-voltage eapaeitors

familiarize

in

ease of aeeidental

faetor if

risk

preeautions

voltage

high

off

points.

eharge

-Discharge

voltage

equipment

However,

equipment.

An

human heartbeats.

most

voltage

eontaet

you

volts

when the

may be retained

needlessly.

yourself

of

shoek

eleetrieal

poses

know and

is

high voltage

while

beeause

shock

hazardous sinee

even

an

Your normal

exposed

with

eontaet

observe

present

is operating

unit

Remove

making

removing

after

equipment

the

with

remember

test equipment

testing

eausing

Voltage

greater

work

high voltage,

servieing

when

indefinitely,

eapaeitors

test eonneetions

high voltage

that

must often

10

as

it

with a the

housings and

produee

ean

threat

habits should

high

following

with

power.

being

exposes

be

milliamps

low as

and

this the

espeeially

a

tested

35

lethal

a

beeause

that

voltage.

safety

oseilloseope.

removed.

ease

grounded

eovers

high-voltage

in

and the

may appear

you

to a

performed

of eurrent

de or

volts

eument

voltage

sueh

inelude all

steer eurrent

will

You

will

preeautions:

Observe

Remember

CRT

the

at

test

when

only

loeation

unexpeeted

at

eertain

where

pass

to

ae rms

under

ean

aeeepted

signifi-

soeket

after

lead

neees-

eireuits.

of

all

its

4.

Use insulated are

5. Use the probe. provide

When using the oseilloseope, the

6. ehassis ground

hazard.

1.

When using a

portion.

8. When testing ae on some any off.

insulated floor

an

surfaee on whieh

work

damp

not

Be

and wire eonneetion or

time the equipment

or wet.

time-proven

partieularly

good ground

a

housing of

probe,

powered

power

input eireuits sueh as

rfone

return

toueh only

material or a

hand in the

eareful

the

is

eontinued

to

path.

oseillos-eope

float the oseilloseope;

equipment,

eonneeted

large,

plaee

to

poeketn

avoid

ground

at

the insulated

remember

the

to an

inside baek

on

insulated

equipment;

teehnique

eontaeting

of the

wire

portion.

outlet,

ae

ground.

that ae switeh,

eover

earth

on-off

floor

make

and

while

nearby

a

3-wire

Do

to do so

Never

line fuses,

even

mat to stand

eertain sueh

handling an

metal

ae

not attempt

may

voltage

power the equipment

if

objeet

power

pose

toueh

the exposed

is usually

transformer,

plug

a

and an

on,

surfaees

instrument

that eould

pla_ees defeat the

to

great

safety

present

turned

is

the

tip

ete.

v

SERVICE

MANUAL

for

B

MODEL

SMHz

fhis senrice manual is intended

only. To qnlified

I}

High voltage of ment is operating. whenever is

turned off. Observe all high is removed from result in fatal

avoid electric shoclg do not

to do so.

approximately 1,400

AC line voltage is

the

power

ae

the oseilloseope.

eleetrie shoek.

eord is eonneeted to a live

K-PRECISION

&

14O3A and

1 4O5

OSCILLOSCOPE

WARlrllNG

use by

for

voltage

Contaeting

qwlifi.ed

perform

volts de

present

safety

preeautions

electronfcs technfcians

senlicing

present

is

on the input

outlet,

exposed

urless

when

even when

high voltage eould

you

this instru-

power

eireuits

if the seope

housing

the

are

{lF

K'

tulA€

6470 W. Contland

Telephone

use this

-

address

for

teehnieal inquiries

luTERm,ATtotuAt coRP.

|

St. . Chicago,

2) 889-1 448

[31

and

lL

replaeement

60635

parts

orders

TABLE

TESTINSTRUMENTSAFETY

OF

o o o... o

CONTENTS

r.....

r o..

o..inside

front

v

Page

eover

INTRODUCTION

SPECIFICATIONS..

CONTROTS

CIRCUIT

ADJUSTMENTS ..

MAINTENANCEo

TROUBLESHOOIjNG... o....... r r.

PARTS IJST.

VOLTAGE

CIRCUITBOARD

SCHEMATIC DIAGRAM o... o r........

HISTORY

DESCRIPTION........... .......

CHART.... r o... r...

OF

.......

o........ o....

INDICATORS. r... r

AND

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MAP.

PRODUCTTON CHANGES...

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13

1?

20

24

.29

30

o.....

o...31

o ..32

ti

Y,

SERVICE

HINTTI

o..... r... r

...

BEFEBBN CE

Model 1403A

Instruetion Modell40SASehematie Model 1405

Model

Instruetion

1405Sehematie

Manual

Diagram &

Manual

Diagram & PartsList ...o...

' ' r r...

PI'BIICATIONS

o . . . . .

PartsList .

o... t.....

o..

o..........

r r..

. . . . . . . . . o . o

.

o o.......

o. o.... .

o o. o

33

o..

r.

480-17?-9-001

.

499-085-9-001

480-26?-9-001

499-164-9-001

v

INTRODUClTON

SCOPE

This

Model

through

It also

produetion

manual. the loose

The

tion, produetion

and repair of

DESCRTPIION

f

The B & K-Preeision Oseilloseopes general waveforms. round

whieh viewed also featues divisions

The vertieal to 5 M Input value uator

variable waveform vided

frIANUAL

OF

serviee manual 1403A

the

Produetion

printing

ttAddendumrt

"History

at the rear

purpose

CRT with a 12 x tZ overlays

on about 8 x 10

amplitude

Hz,

impedanee

for

offers 1:1, 10:1

gain

allow

to

from

end of

eovers Model

until

of this manual

ehanges

the instruments.

OF EQUTPMENT

are

These

a dB

ehannel has

and

sensitivity of 10

oseilloseopes.

eontrol

amplitude.

external

the start of

produetion.

the

ehanges

sheets.

of Produetion

of

the marrual,

whieh

eompaet,

instruments

oseilloseopes

the

CRT.

seale, refereneed

equals

is 1 Megohm,

eovers

1405

printing

Model 1403A

divisions.

and 100:1

offers fully

Terminals

B & K-Preeision

from

of this

whieh oeeur after

will be

Changes"

may

affeet servieing

single

for observing

division

Waveforms

The

0 dB.

bandwidth

a

A three-step

signals to be

produetion

start

the

eovered by

itemizes all

and

use a 3-ineh

gratieule gratieule

mV/division.

the standard

steps,

adjustable

are

also

of

serviee

see-

1405

traee,

ean be

to

six

of de

atten-

plus

a

pro-

applied

direetly to

the

CRT.

The horizontal

sweep,

to

span the 10

be synehronized

ean

observed

tivity of available, with peak.

X-Y

In

beeomes a variable

m aximum Bandwidth is up to 250 kHz.

provided

DIFFERENCES

1405

AND

Eleetrieally, the nearly identieal. hardware The Model 1405

Model ease eolor, the in

m

EXCLUSTON

1403.

in funetion

major ieations.

1403A

front

the

anual.

This

Although the Model 1403 has

differenees

the vertieal

ehannel uses

with four

(internal

1 division.

operation, the

sensitivity

for

and meehanieal

panel.

rrParts

serviee manual does not

ranges

Hz to

syne) with a

a sensitivity of 2

gain

intensity

BETWEEN

Model 1403A

However,

beeame a replaeement

in

19?9,

and many eosmetie differenees on

All differenees

Listn seetion of this

mODEL 1403

OF

to

Model 1403A, there

in eireuit design and speeif-

defleetion

and

100 kHz

to

the

External

X-axis

of 300 modulation, if desired.

parts featured

and

plates

reeurrent

variable

a

band. The

waveform being

trigger

syne

volts

horizontal

amplifier with mV A Z-axis

ITIODEI.S 1403A

and

almost

are different.

are itemized

eontrol

sweep

sensi-

is also

peak-to-

ehannel

per

division.

input is

1405

all external

for the

different

a

serviee

eover

Model

a similarity

are

several

of

type

are

rl7

SPECIFICATIONS

Y/

CATHODE BAY

C3L2P31B or 75AV831.

VERTICAL

Defleetion

10

mV/div

Frequeney

DC: AC: 2 Hz

Input

Impedanee:

1 MO

shunted by

Overshoot:

5% or less.

Attenuator:

t, 1-/L0,

Gain Control Range:

Continuously than 22

Rated Max,imum

300

V

TUBE

AMPIIFTER

Sensitivity:

better.

or

Response:

de to

1/100 multiplier

dB.

Input Voltage:

(de

+

ae

35

(-3

pF

max.

or 600

5 MHz

to 5 MHz

variable,

peak)

Og).

(-3

dB).

within

range

p-p.

V

t596.

greater

SWEEP CHARACITRISTICS

Sweep

Sweep Linearity:

Synehronization:

Signal Amplitude Required For Synehronization:

INTENSITY IIIODULAIION

Required

DIBECT DEFLECTION

Defl eetion

Input Impedanee:

Frequeney: 10 Hz in 4 ranges.

Within

Internal

Internal: More than 1 div defleetion

External:

10 V/div

2.2 MQ

100 kHz

to

5%.

or external,

on eathode ray

More

Signalz

Sensitivity:

or better.

shunted

by 25

eontinuously

negative

than 2 V

25

TERMINATS

pF

p-p.

V

or less.

variable

slope.

tube

sereen.

V

HORIZONTAL

Defleetion

300 mV/div

Frequeney

DC

to 250 kHz set with range.

Input

1 (SYNC

Attenuator

Continuously

Rated

100

maximum.

at

EXT.

Impedanee:

(120%)

M0

switeh

Maximum

p-p.

V

AfrTPLIFIER

Sensitivity:

or better.

Response3

with

GAIN

shunted by

to

set

(nXt

GAIN):

variable to zero.

Input

EXT. GAIN eontrol

DC to

eontrol

INT).

Voltage:

approx.

set at

30

40

pF

kHz

mid-

max

POWER

delivered for

DIUENSIONS,

Width: 7 Height: 6o

Depth: WEIGIIT ACCEf|SORIES SUPPLIED

Test Leads. Spare Instruetion

Sehematie

RBQIIIREMENTS

Ll?

/230

VAC, 50/60 Hz,

Fuse.

use on

OVERALL

Manual.

Diagram &

117

-L/2" (154

IL-27

8.36 lbs

/32n

VAC,

(1gO

mm),

(300

(3.8

Parts

16 watts

50/60 Hz).

mm).

kg).

List.

(Unit

^.

v

CONTROIS AND

INDICATORS

BOTTOM

@ @ @rnoruTpANELO)

@

PANEL

l8ffE

sreec,.eer6s1r.y

I

Z

axrS

rNPut

crr9

2t

v

otq

REAR

PANEL

i*tr?F

l-5'{-r

L,mn,,,J

;''6':

-

FRONT

PANEL

INDICATORS

1.

Neon

Pilot

operating.

2.

POWER

3.

EXT SYNC/HOR external syne or

signal.

adjaeent

4.

+

Jaek

Fig. 1. Model 1405

CONTROIS

Lamp.

Lights

Switetu Power

INPUT

external

Conneet

ground

Earth

signal eom mon to

terminal.

and ehassis

AND

when

seope

ON-OFF switeh.

Jaek

Input

horizontal

ground.

Controls And Indieators.

VERT

5.

INPUT signal adjaeent

is

AC-DC

vertieal input

vertieal

and, therefore, de

for

bloeked,

eomponent only.

the

input

is direetly allows both de and ae eomponents of signal

to eause vertieal defleetion.

Jaelc

Input

for vertieal Conneet signal eommon to the ground

Switetr. Seleetor

input

permitting

jaek.

switeh

eoupling. In AC

position,

is eapaeitively eoupled

eomponent of signal

observation of ae

position,

DC

In

eoupled and,

vertieal

therefore,

for

is

It

CONTROI,SI

7.

V Coarse vertieal switeh. signals applied before eonneetion providing

display position

applied to vertieal uated. amplifier signal vertieal amplifier input value.

adjustment

position, neeted from vertieal of amplifier is

traee at 0 input, and is de balanee adjustments.

Below

0.2

to 8 V

AND INDICATOBS

ATT Switeh. Vertieal

amplitude

Attenuates high

to VERT INPUT terminal

suitable level for

on

is most

1/10

In

is

level 1/100

V GAIN eontrol

VERT

volts referenee

Signal Voltage

To Be ileasrned (ranges

p-p

0.8 V p-p

sereen.

CRT

position,

attenuated to l/10

within eaeh

INPUT

grounded.

eorreet

overlap)

(0.3

(0.0?

to 3 Vrms)

Above2Vp-p(0.?Vrms)

8.

V GAIN Cmtrol Vertieal Fine

adjustment This eontrol maximum

ftlff

range of

sensitivity;

of

must

V

ATTenuator.

attenuator.

range

to vertieal

n1n

sensitive range;

amplifier is unatten-

input to vertieal

position

to 1/100 of input

range.

jaek

amplifier and input

for de

position

V

rms)

seleetor

amplitude amplifier,

waveform

(10

mV/div)

signal

of

attenuates

provides

In GND

is diseon-

provides

This

eoupled

for making

Ventieal

Attenuator

Pcition

1

LlLO

1/100

gain

control.

waveform amplitude.

be

fully eloekwise

10

e.g.

mV/div in

input

fine

for

GAIN

position

defleetion. In this ator eonneeted applied at horizontal

L2.

SWEEP VARI/EXT GAIN sweep signal switeh gain

horizontal with speeifieations).

CRT Gratieule-

13. aerylie resin and both eoarse and

waveform on CRT

a

-3, -6, tude from

These frequeney response m easurem

L4.

SYNC INT-BXT position,

of vertieal amplifier, waveform In EXT signal synehronized waveform signal m signal

eontrol)

is

disabled

frequeney adjustment

gain

is

set to EXT,

horizontal ehanneL Note that

of

position

dB seale on

-10, graduations

sweep

position,

applied

ust

being

within

seleets

and HOR

horizontal amplifier. Signal

to

HOR INPUT

(X-axis)

eontrol

frequeney

of

has

fine, to aid

gratieule,

the

-20

and

to 0

REF

Switeh.

is synehronized

being observed on CRT

sweep

to

have a time

observed.

range. EXT

eaeh

external

mode, sweep

defleetion.

When

this eontrol

response varies

this eontrol

Gratieule

engraved

sereen.

dB

and

dB is 6

are eonvenient

In whieh is also the is

EXT SYNC

horizontal

INPUT

jaek

Control

and external

SWEEP

is

in

m easuring

There is

indexed at 0,

REF. Ampli-

ents.

lNTernal syne

synehronized

display, this

relationship

gener-

jaek

is

produees

Fine

RANGE

adjusts

(refer

made of

markitrgs,

divisions.

to output

jaek.

to

also

for

sereen.

to

For

to

Y

v

9.

10.

11.

POSITION

t

eontrol Moves down

{> position left or

SWEBP RANGE frequeney

100-1k, represent that frequeney

Control Vertieal

entire

on CRT POSffiON

right

are

sereen.

Control Horizontal

eontrol Moves

on

CRT sereen.

Control Coarse

seleetor switeh. The

1k-10 k,

the possible

and 10 k-100 k

range

eontrol

of sweep frequeneies

with the

(SWEEP

position

waveform

entire waveform

up and

sweep

10-100,

positions

fine

sweep

VARI/EXT

BOTTOIII

15. DC

16. HOR

PANEL

BALANCE Control adjustm ent adjustment should

minimum vertieal V GAIN eloekwise V

ATT set

GAIN

fier ealibration adjustment.

CONTROII;

for

eontrol

to full to

GND).

Control

balanee

DC

vertieal amplifier.

ze?o

be set

movement

rotated

is

eountereloekwise

for

of

from

Horizontal

traee as

This

or

full

(with

ampli-

v

CONTROI^S

INDICATORS!

AND

v

REAR

L7.

18. POCUS Control

19.

20.

2L.

PANEL CONTROTS

INTENSITY ContrcL Adjusts brightness

of traee.

trace. Z

AXS

,

intensity modulation. an

ae

25 V

portion negative blanks

GND

ground. V DIB Terminal Direet

terminaL

Adjusts elarity of

Terminal Input

This

voltage

p-p

to blank

of

signal

portion

sereen.

Terminal Earth

pulse

or

the

inereases

reduees

An external

terminal for

jaek

requires of approximately sereen.

defleetion input

signal ean be

Positive

intensity, and

intensity or

and ehassis

routed

tion (eonneet

GND switeh division.

DIR-NOR

22.

vertieal deflection position,

eonneeted to for VERT

DIR and GND input

neeted to

23.

CBT AfrJ. Loosen and rotate tilt.

Power

24.

direetly

plates

terminal), and setting DIR-NOR

to DIR. Sensitivity

normal

INPUT

Ccd.

to

by

eonneetion

signal

Switeh.

output of

vertieal defleetion

eommon to the adjaeent

vertieal defleetion

oseilloseope operation

jaek.

Tlaee rotation

CRT to eorreet traee

vertieal

CRT

to this terminal

is 10 volts

Seleets

plates.

vertieal

In

input to

DIReet

terminals are eon-

deflee-

per

CRT

NORmal

In

amplifier

plates

using

position,

plates.

adjustment.

is

V

rI'

rt

EIRCIITT

DESCRIPNON

v

BLOCK DIAGBAM

Refer

the

The vertieal attenuator The AC-DC direet

eal attenuator) vertieal amplifier eoupled approximately

tivity of approximately

The

trol quired.

applied

CRT when When

output of

ed and minals is applied fleetion

The

sweep

zontal generator whieh queney RANGE switeh, and

provided INT-EXT switeh seleets sweep the

The sawtooth horizontal amplifier and applied zontal horizontal differential

mately 35 also be used to amplify applied at

the

varied

to Fig.

oseilloseope.

vertieal ehannel

VERT INPUT

switeh,

eoupling,

differential

vertieal attenuator and reduee the signal when

output of

The

to the

the NOR-DIR

NOR-DIR

the

the vertieal amplifier

a signal

plates.

horizontal ehannel eireuits

generator

amplifier. The

is a

produees

range

by the SWEEP VAR

generator from

EXT SYNC

defleetion

amplifier

dB. The

the HOR INPUT

EXT GAIN eontrol

by about

ANALYSXS

2, whieh is a

and vertieal

signal

whieh seleets Md through to the vertieal

is a highly stable,

amplifier with

61

vertieal defleetion

from the V DIR and

free

the sweep waveform.

input.

10 dB.

giving

dB,

the vertieal amplifier

switeh is set

direetly to the

for

a time

running sawtooth

is seleeted

fine frequeney eontrol

the

wave

plates

is a stable,

with a

horizontal

bloek diagram

eireuits

is

applied

the V ATT

a maximum

10 mV

vertieal

less output

switeh is

base and

reeurrent type

by the SWEEP

the syne signal

vertieal ehannel,

is

amplified

of the CRT.

gain

an external jaek.

allows

of

inelude

amplifier.

through

eapaeitive

amplifier.

a

per

gain

plates

set to NOR.

to

diseonneet-

is

GND

vertieal

inelude

oseillator

eontrol

to the

direet eoupled

of approxi-

amplifier

In this

gain.

the

the the

or

(verti-

The

direet-

gain

of

sensi-

division.

eon-

re-

is

of the

the

DIR,

ter-

de-

hori-

a

sweep

Its fre-

The

the

for

or

the

by

hori-

The

may signal mode,

be

to

is

The

ages

-15

V,

preamplifier

+170

thg horizontal voltage souree aeeeleration

Z-axis where

the CRT

of

YEBIICAL

Refer

vertieal

the matie

full eireuit Input Cireuit

The the seleets position,

a

input. In

is

Cl direetly

Vertieal

is

The

10

is expands

sensitivity

1

V/div. networks, attenuate fier eapaeitors ey eompensation

mateh

to danee

fourth

A IN PUT vertieal eonvenient

power

for

and

input

it

diagram

vertieal

AC-DC

or

bypassed

basie sensitivity

mV/division.

by

of 1

supply

all eireuits.

-6

V sourees

and sweep

V souree

final amplifier

provides

voltage

is applied

may be

beam.

CHANNEL

to Fig.

detaills.

bypasses eapaeitor

Cl

the

to the attenuator

Attenuator

the

steps of

This is aehieved

seleeted

the input

Xl

TC101

the

Megohm

step

path

preamplifier.

0-volt

used as

3

ehannel

in

input

eoupling

is eonneeted

DC eoupling

and

input

(direet),

Xl step.

of

and

provides

The

are used

generator eireuits.

is used

for

for a

eireuits

the

range

10

by S1a and

to

X10,

and

for the

is

switeh

grounds the

referenee.

in the

stages.

about the CRT to

intensity

CIRCI'NS

simplified

of the

rear

signal

switeh,

in series position,

input

switeh.

of the

vertieal

The

by offering

mV/div, 0.1

by

the vertieal

or

TC102

XL() and eonstant

A

maintained

S1

This establishes

operating

regulated

in the

vertieal

-1400 beam.

eontrol

the

modulation

diagram

to the

and

manual

first

is

53. Cl.

signal

vertieal

voltage

Slb'

X100. Trimmer

provide

X100

input

in all

opens the

input

volt-

+15

vertieal

high

The

volts

grid'

sehe-

routed Switeh In the AC

with

eapaeitor

is eoupled

ehannel

attenuator

three

V/div'

divider

whieh

preampli-

frequen-

steps' impesteps. VERT

of

V'

and

The

of

for

to

S3

the

and

the

a

;

v

CIRCTITT

DESCRIPTION

v

CRT

V.AMP

Ol01l,0111

SWEEP

NERAT

12.

EXT

EXT SrYrC

I]IPUT

HOR

01

13

H.

AMP

0114-Q116

+15V +170V

POWE R

SUPPLY

|}

Vertieal

The vertieal eoupled three

Q103,

sistor

stages,

a

amplifier

The first stage Q101-Q103,

impedanee. It on the 1 Megohm side of

for the entire vertieal amplifier

anee VR101 balanee. overload signal

fier in input

ground

stages.

a differential amplifier eonfiguration;

signal applied

souree of eommon

In

rt

the seeond

lifier,

Q104

Preamplifier

differential

an FET

buffer

stage

whieh

has negligible

Q102

(OC

establishes

BAL)

FET

Q101

proteetion

for

Q102

stage

and

Q105

2.

preamplifier

amplifier

input amplifier

Q104-Q105,

Fig.

is a

made up of

and a tran-

Bloek Diagram.

direet-

Q101-

Ql06-Ql09.

is an

presents

FET

a

input

very

amplifier,

high

shunting

input

effeet

input resistanee. The signal

internal de

the

bal-

board.

allows and

Q102 and

Q103

adjustment

provides

FET

Q103

and

sueeeeding

are souree

input voltage

of de

establishes

ampli-

eoupled

the

to

gate

Q102

FET

of

is eoupled

Q103.

the vertieal

are emitter-followers

to the

preamp-

to

Q102

and

impedanee

very

high impedanee amplifier.

Q106-Q109

vertieal

eontrolled

is whieh

Q10S

preamplifier.

limits the

and maintained baek output

RL22 and and

Ventieal

provided

voltage

and R123

Q109

Ql11.

Final Amplifien

vertieal

The

and

differential

frequeney

trimmed

by adjustment

Q103.

These

eonverters,

impedanee

form

signal

the panel

drive

by front

eurrent

Q109.

through

Stability

the

C132

by

developed

is

from emitter

to the

fed

final amplifier

amplifier

transistors

eonverting

of the

Vertieal

FETrs

for

third

the

stage

gain

potentiometer

the bases

to

fed

of

Q106-Q109

negative

of

use

R178.

and

aeross

euments

final amplifier'

stage

and

Q110

Ql11..

eompensation'network

TC103

to aehieve

as

aet

from

to a

the

low

transistor

the

of

(V

GAIN)

VRl

of

is

feed-

Signal

resistors

of

Q108 Q110

ineludes

high

A

may

be

the

CIRCIIIT

DESCRIPITON

MHz

5 tioning. VRz, and the CRT are

and NOR. At volts

vertieal defleetion eonneeted ground.

output

eireuits for internal syne.

HOruZONTAL CHANNBL CIBCITrIII

the

sehematie

for full Sweep Generator

reeurrent sweep sawtooth around

lator operates eonstant of eireuit of SWEEP tanee eomponent of the

to the 10-100 ing 100-1 k

eapaeitanee

10 k

eapaeitanee of 390

10 k-100 the SWEEP series resistor resistanee

RC time

fully highest.

the

turned

bandwidth. Front

is

aeeomplished by

eOS,

I

Q111.

Q111,

With

A sample of

Refer

horizontal

The

a eapaeitanee

eireuit

sweep

when

this

per

division.

NOR-DIR switeh

direetly

is available to

to

diagram

eireuit

sweep

transistors frequeney

Q113

RANGE switeh, 32,

position,

k

VARI/EXT GAIN eontrol, VR4,

eomponent

eonstant

eountereloekwise

The

eloekwise.

it shifts

as

The vertieal defleetion

fed from

NOR-DIR switeh

point,

to the V DIR terminal and

the

4 for

Fig.

ehannel

at

details.

generator

Q112

at whieh determined

is

the eomponents

(Ca,

position,

of 0.47

C4

of 0.047

C5 is seleeted,

is

seleeted. In

R141, are seleeted as the

is

time eonstant is redueed and

RC

frequeney

panel

the de

the

waveform

55 set to

plates

vertieal final amplifier

the

a simplified

eireuits and to

the rear of

eireuit eonsists of a

and

C4, C5, VR4 and

RC eireuit:

C3 is seleeted,

UF;

is

seleeted,

pF;

when set to

pF;

and, when set to the

the stray

of

the

greatest

and its resistanee

is inereased

vertieal

potentiom

bias of

eolleetors of

of

the CRT

horizontal

oseillator

Q113.

the sawtooth

by the

in

seleets the

when set

eapaeitanee

eaeh

eireuit.

RC

when VR4

posi-

eter

Q110

plates

Q110

is

SS

set

is about

DIR, the

are

ehannel

diagram

the

manual

the

built

oseil-

time

RC

the

emitter

R141).

eapaei-

when

provid-

to the

providing

1 k-

the

providing

ease, the

and

The

V.R4 is

as

of

to

10

of

set

of

its

is is

5 is a

Fig. sweep help illustrate operation

manner applied. portion

emitter), voltage With eapaeitor VR4 and mined by the RC deseribed. As the voltage at the emitter tively. tively, the threshold

threshold

Q113

sweep lished by the voltage divider VR4, develops a

whieh

Ql12, C108

for the sawtooth most

Q112 eolleetor,

of eharge is again

ramp begins. This eyele peated.

a

approximately limited

a

eapaeitor eharge eyele.

a

waveforms Q112,

inverted negative-going inverted of

oeeurs

sweep,

generator

First,

Q113

whieh deereases

The

eonduets and range

and R141. This eonduetion

is fed

cutting

and R135 determine

Ql12.

point.

is inverted

Q113

period.

Now let us eonsider

syne

superimposed

Ql13.

just

partial

eireuit with

let us eonsider

of operation

During the

of

the sweep

Q112

at

R141. The

The voltage eontinues

negative-going

of eonduetion

to

eut off, and the

The sawtooth

to the

signal is

and applied

to

it will bias

eonduets

the base

off, the seleeted

eut

eharges toward

time eonstant

of

eonduetion

eapaeitor

negative

baek through

it

off.

This is the very short

waveform

The negative

to a

and is direetly eoupled

eontrol

At the end

+2

most linear

applied.

in Fig. 5. Syne

edge

positive-going

a

If this superimposed

before

sehematie

of the

where

negative-going

waveform

and establishes

of

Q113,

rate of eharge

eapaeitor

of

the bias

ramp

of

quickly

to

pulse

The RC

returns to

positive

sweep

the

waveform

volts to

eireuit

on the

to the

of the

the end

Q113

diagram

waveforms

eireuit.

the

no

eutting

-15

Q113

to ramp

is reaehed.

ends

Q113

diseharges

the de

of R138,

at

C108

time eonstant

the eutoff

pulse

this

of

negative-going

eontinuously

-2

portion

operation

Refer

signals

sweep

base of

syne

edge at

of a

into

eonduetion

of the

to

running

free

signal

syne

(at

sweep

volts through

is deter-

previously

as eharges,

ramps

on

Q113,

when the

reaehed.

is

value

of

the eolleetor,

to the

interval when

positive-

its

the

at

pulse

to the base

eapaeitor

pulse,

ramps

volts, and

the sweep

of

again

are

reset

Q113.

input

signal

the

positive

free-running

is

ramp Ql13

de

a

it off.

range

the neganega-

until

the

estab-

Q113,

Q113

base of

of

period

base of

at the

dis-

Q113

re-

from

when

the

to

fed to

pulse,

base edge

and

is

A

is

b

a

Yt

Bk Precision 1405, 1403A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual