BK Precision 177/V-95 User manual

@r77lv-ss

YACUUM

TUBE

VOLTMETER

DYNASCAN

COF|PORANCfN

TEST INSTRU MI]NT

WARNING

SAI.'ETY

Normal use of

shock

becausc testing must often be shock causing 10 hcartbeats. Higher voltages producc considered dangcrous conditions. Your normal contaot with accidental and observe the following safety

a lcthal current. However, voltage

contact

Don't

1.

2. Use

3. Use the

4. Always use

cxpose high voltage needlessly. Removc housings Turn off cquipmcnt while making tcst connections in liigh-voltagc high-voltagc capacitors

an

work

surfacc on which to

or wet. Where insulated floor surfaoc is not

probc.

good ground

a

wherc most recent chassis depending upon which way prescnt or

the cquipment undcr test may result from connecting instruments instrumcnts with 3-wire TR-l l0 Isolation Transfbrmer is suitablc for

tcst cquipmcnt cxposes

milliamps of ourrent to

cxposed high

with a high

insulated floor

timc-proven

particularly

Be

return

an

side

onc

tclevision

such

of

a dangcrous shock hazard if the chassis

to a

pose

an even

hazardous

and

isolation

of thc AC

cquipmcnt may be floating

"hot"

habits

work

voltage,

"one

carcful to avoid contacting a ncarby mctal

path.

and that will steer

voltage.

precautions:

removing

after

material or a

placc

hand in the

transformer to

power

scts

and audio cquipment. Without

the

chassis. The

power

you

performed

greatcr

since it can

should include

You will significantly

power.

large,

cquipment;

line is connected

2-wire

ground

plugs

is

ccrtain

to a

where exposed voltage

pass

through the heart will stop most human

thrcat because such voltage

as low as 35 volts DC

produce

all accepted current away

insulated floor mat to stand

and make certain such surfaces

available, wcar hcavy

pocket"

tcchniquc while handling

power

transformerless

line voltage

at

power

AC

is touchcd,

lead

of rnost oscilloscopcs

at earth

ground.

most applications.

amount

a

reducc thc risk factor if

and

directly to the chassis.

plug

is

but

Thc B & K-PRECISION Model

danger fiom

of

present.

is

or AC RMS should

lcthal

current under ccrtain

practices

from

covers

gloves.

"hot

isolation

an

(120

inserted. Not

damage

ground

the

that

your

only

circuits. Dischargc

on, and

objcct that could

chassis"

VAC,

to test

lcad

and

elcctrical electrical

An

can more easily

will

heart in

whcn

an

are not damp

an instrunrcnt

equipntcnt,

This

transformer, the

Hz in

60

only does

instrumcnts

to

most

be

prevcnt

casc of

you

know

ncccssary.

insulated

provide

includes

USA),

this

some

test

other tost

On test instruments

5. outlet. This is a safcty

ground.

possiblc,

6. If

high voltagc points

Also rcmember that AC line voltagc

7.

on-offswitchcs, fuses,

8. Ncvcr work

(cardio-pulmonary

larniliarize

in defcctivc cquipmcnt.

alone.

or any equipmcnt with

fcaturc to kccp tho housing

points.

yoursclf

Ilowcvcr,

powcr

Someonc should bc

rcsuscitation) first aid is highly

a 3-wire AC

or othcr cxposed elcmcnts

with

the cquipmcnt bcing tcstcd

rcmembcr

prcscnt

is

transformcrs, etc., even when

ncarby to rcndcr

high voltagc

that

on somc

rcoonrmendcd.

power

aid

power plug,

may appear

input circuit

equipment

the

if nccessary. Training

usc only

and thc

location

at

points

is turned off.

a 3-wirc

oarth

at

of its

uncxpcctcd

such as

on CPR

TABLE

OF

CONTENTS

KeyFeatures.........

Specifications

lmportant

Advantages

Accessories

D.C.

A.C.

Resistance

Reading

Using

Circuit

Maintenance

Warranty

Notes

of the

Voltage

Measurements

the

db

Descriptiou

Service

VTVM

Measurements

Mcasurements

Meter

Scale

Suggestions

Instructions

Page

I

3

R

o

t)

8 8

I 1t t2 t4

1.

Wide vision

6" x 4" meter

KEY

scale

FEATURES

for

efiortless

reading.

2. Anti-parallax

3. rnput

4.

5. Measures

6.

7. Measures

8. Measures

9.

10. Zero

11.

impedance important high

impedance

special

parameters

circuit

Measures

Calibrated DB

center

"Transit"

mirror

feature when

circuitry.

0-.5

volt D.c.

D.C.

voltage

A.C.

RMS voltage

peak-to-peak,

A.C.

resistances

scale.

on

meter

position

switch

permits

of 11 megohms

in

solid

up

scale, useful

maximum

measuring

range,

useful

state

up

1500

to

up to 1500

sine

1000

to

automatically

on

all D.c.

oscillator

for

circuitry.

volts.

and

complex

megohms.

for F.M.

clemps

scale-reading

voltage

grid-bias,

accurate

discriminator

measurements

voltages

protects

and

accuracy.

rzrnges.

AGC/AVC

up

to 4000

aligmment'

meter

This is

voltage

of critical

volts.

movement.

a very

i-i

SPECIFICATIONS

DC VOLTMETER.

8 Ranges

Input

Resistance Sensitivity Circuit Accuracy

AC

VOLTMETER.

7

Ranges

7

Ranges

Frequency Response Accuracy DB Scale

OHMMETER,

TRanges

METER

MULTIPLIERS

TUBE

(R.M.S.)

(Peak-to-peak)

ELECTRONIC:

ELEC'TRONIC:

...0-.5, r.5, 5, 15,50,

.

. . . . Ralanced

ELEC'TRONIC:

.......0-1.5,

. . . .. . . . .0-.4,

(5V

Range). .

. .

.

....t%

......12AU7,

scale.

.11

Megohms

.7[

Megohms

.,1-3% full scale.

-+1

. .isTo ..-6

*24 to l-66db

line on 0-5

...0-1000

I

(x100K),

center

No

. .100

Anti-parallax

bridge

5, 15,

50, 150,

14,

40,

db 40 to +16db,

meg

battery

p.A

precision

L40,400,

Hz

full

scale.

+46db,

(0.775

volts

(x1),10,000

(x1000),

1000

scale

required

movement, plastic

twin

150,500,

(1

I\4egohm

per-volt

using

500, 1500 volts

to 4 MIIz

+4 to

*34

volts

AC scale

10

meg

on

Rx1.

mirror.

type.

triode

bridge.

1b00

probe).

in

on 1.5

volt range.

twin triode.

1400, 4000

(600

+26db, f 14

to

into

(x10),100,000

meg

(xl

for ohmmeter.

volts.

ohms source).

to

+56db, +44

600 ohm

-

0db).

(x10K),

meg). 10

case.

volts

fulr

full scale.

+36db,

to

(x100),

100

meg

ohms

POWER REQUIREMENTS

lO5-L25 volts 50-60 cycle AC.

whe voltage, person traincd Safety"

There

cotnrt,, chassis

"float"

grouaded'

ts leutl nortnulll' common to should

one chassis"

covcr of

the

become

power treat

isolated

i

when the exposed

n this

v'rvM

thcrc

and

is

the

qualifie

using

recomme

t:utt

bc

a

gr.urttl

.r

and

case

the

metcr

Howevcr,

of

the

meter

bc

corre(ted

read

is

that potential.

not

be

touchcd

of

the

most

transformerless

of

this

manual

VTVM

line

any

handling

is

"hot."

For

and

any

ac-powcred

chassis

or earth

the

portion.

tip

OPERATING

is used

always

VTVM

ndations

shock

of the

is t;ottnectatl

conncctcd

The

connccted

to

a certain

should

d

to

work

listeci

h.azurtr.lrom

leutl

,J

VTVM

for

measuring

this

to

u

meter while

com"only

ac-powercd

for

a

safety,

"hot

chassis"

equipment

grouncl

probe,

test

fu[

make

measurements

amount

qualified

be

a

in such

on

the inside

touchirlg

tha

ilrcter

are

isorate

voltage

rnust

be done

tn

thc

grcturttrecr

to

a high

casc

shoulcl

connccted

encountercd

equiprnent

explanation

"hot"

to

a

always

usc

ccluipment

"hot

as

chassis. touch

WARNINGS

in

of danger

electronrcs

conditions.

is

cttnncc,tetl

d from

between

with cltassis pr.tirt

vortage

be iniurated

in

this

chassis,

an

isolated

chassis"

onry

front

thc

caution.

utttl

tn

the

point,

manner.

shock

(see

of

the

under

the

rnsurated

obscrve

carth

cusc

equipmcnt

fiorn

elcctric

technician

thc

cover

of

(asc

o.r

tht'vrvrl

t.

u ltigh

ground

polnts,

rwo

The

t,rnitrt.n

of

the

equipment

thc

case

from ground

obscrve

hazards

item

hazard).

case

of

+

If

is

on

the

transformer

test.

To

be on

unless you

portion.

that

contains

or othcrwise

..Test

this

manual.

vortugc

pcrrnit

to

'crther

VTVM

under

of

the

VTVM

und

Cuution.

testing tne in'siae

the

common

vrvM

between

the

o."

rura

Never

high

shock.

The

Instrument

u,hcrt

trtt,

p.irtt.

The

you

to

of

which

gr.uttd

,r

untl

should

test.

If

thc

rises

it.

..r.

,,hot

of

front

lead

wrll

also

thc

ac

sate

side,

it

t

u,

un

touch

*"*--

ADVANTAGES OF

THE VTYM

'I'he

greatest impedance. This feature impedance higher degree showl source here voltage ment the

in Figure of voltage.

that the voltagc

across either resistor

on the 0-100 volt scale however, we

discrepancy. As shown

considered

A simple

tor. parallel

the circuit. Now

circuit to be

of the many

circuits

of

accuracy. 1A

a resistor of

Ohm's Larv calculation

the first

makes

such as oscillator

two 500K

A simple knowledge

drop

across

in Figure 1A the

2 meg.,

400K,

500K resistor has

-t-

v

loo

_l_

R(rorAL)

(ruerER

\oLTAGE AcRoss Rz AND

-T-

rN

PARALLEL

advantages ofiered

possible

As a simple

resistors connected

each resistor

with a 20K

which is connected in

resulting

the measurement

grid

circuits and

illustrative

of

basic fundamentals

ohm-per-volt

obtain a reading

meter

rvill readily

redistribution

in a

approximatety

--MULrrMetEd-'

ON IOOV SCALE=2 MEG.

wlrH Rz)=ffiffffi;aoo

METER=Eoffi

FIGURE

IA

by the

will be 50 volts.

xtQQ=44

VTVM is its

AGC networks

in series across

(on

parallel

shorv the

of voltages

example

non-electronic

of only

100

the

with the

total resistance

of the

56 volts across

voLTs

high input

in

with a much

of this, makes

I\4easuring

type instru-

44 volts.

volt range)

voltage drops in

R:5OO E=56V

high

we have

100 volt

a

it obvious

Why

can be

resis-

500K

of the

it, and

K

the

E_q?rf;.Ll"4ooK

I

K

(APPRox')

I

R=5OO

K

V

E=51

v

loo

_.1_

R(rorAu

(METER

VoLTAGE AcRoss

500K

other

the it. The when total resistance voltage than the

with a high-impedance

low resistance

it is connected.

of 11 megohms

of our

across

actual operating

rN PARALLEL

R2 ANDMETan=#|ft5xloo=4e

resistor in

When a VTVI\{ is used

connected

parallel

the meter

wrrH nz)=*#Hili$F.

FIGURE

parallel

meter

and resistor

voltage.

instument

with the meter

is loading or changing

parallel

in

network

is now approximately

dropping

More accurate

such as the

VTVM

/ruec.oN \

SCALE/

\ANY

IB

has approximately

as shown

with the

only to

readings can only be

VTVM.

R(roTlt-)=4goK

E= 49V

.48MEG.=48o K

voLTs

44

impedance

the

in Figure

500K resistor,

480K, resulting in the

49 volts or a mere

of

18

and the total

I

t

volts

the circuit we

2/6 lowet

obtained

across

have a

Additional aclvantages

t/2

A

volL

full scale sensitivity fractions devices). meter does

of

a volt,

'I'he

VTVM

not cause

Other advantages in

of the VTVM

(which

are often applied between

input impedance

false readings due to current injection in

the high impedance characteristics of the VTVM include ability to acculately measure lines,

high impedance osciilator

measurements.

(Available

re

*F*ffi

d-g]',

ifl

n.

^€

dry

*-t

in solid

range which

state measurements are:

permits

the accurate reading of the

base and emitter of transistor

is important, so that

the connecting of the

the transistor base.

voltages, without upsetting circuit operation,

grid

and other

grid

circuits, insulation

ACCESSORIES

on

separate

MODET AV-2A. Increoses DC voltoge ronge up 50,000

MODET AV-lA. rqnge

up to 250

order)

volrs.

R.F. Probe. lncreoses frequenq

MHz.

the

AGC

on

resistance

lo

The AV-IA

wave

voltages

which

is usecl DC voltage brating

as an

ranges

resistor

The

AV-2A

Accessory

of

The heavy operator leakage

at the test

One

of the most

measurernent

RF

at frequencies

as a half

proportional

converts

HIGH

your

VTVM duty

safety. Two

of 2nd anode

The DYNASCAN following vacuum

-

B&K

-

B&K Model

-

B&K

-

Precision

-

Precision

-

Precision and most

PROBE

enables up

wave

rectifier.

to the

peak

this

VOLTAGE

(available

item

by a factor

plastic

point

handle

oversized

on the

flashover

u:;eful applications

voltage

Models AV-1A

tube voltmeters:

Model 177

375

Model 175

Apparatus Apparatus Apparatus

other VTVM's

operator

the

to make measurements of

to 250 MHz.'rhis probe

peak

value

reading

MULTIPLIER

your

at

The half

wave rectifier circuit

of

the sine wave input

proper

to

the

PROBE

distributor)

of 100.

and

safety-type connector guards

probe

head.

protect

of the AV-2 High

in TV sets.

and AV-2A Probes

Model

V-95 Model V-75 Model 48

11

with

megohms

employs a crystal

diode

develops a

signal. A cali-

sine

reading

has been

on the

VTVM.

developed

to extend all DC voltage

insures maximum

the operator's hands

Voltage Probe

can

be used with

from

is

input resistance

the

See OPERATING

VTVM.

of

WARNINGS

on

page

3

concerning

connection

of aommon

lead

nrerrsur,,DC

Io common in from

rom

f

requirecl, measured, the

pro|e fuli

deflection

RMS

0

for this

position

center

orobe

B-,

instances

most

the

the schematic

AC-OHMS,

the voltage

to

scale

lower

select

for

volts.

and .5

rvill notice

You

special

center

by

scale marking.

set Function

to

VOLTAGE

BE MEASURED

DC VOLTAGE

"grouncl"

or

although

electrical

ancl set

if known.

DC

(500

volts

position.

range

the

scale

simply

TO

having

DC

zero feature

switch

without

reading

applications

"DC".

r.oltages

gide

circuitry

diagram.

the range

If not

switch

point

to be

rvhen on

(0-500

which

the

uoltages.

your

that

such

adjusting

to

MEASUREMENTS

the V'l'VM,

with

voltage

the

of

Set the

to

set to

test

measured.

range in

permits

go

the

Use

vTVM

ZERO

or

RANGE

TO

transformerless

function

a range

probe

volt

you

off

0-5 scale

has

FM discriminator

range

ADJ.

*DC"

in many

and the common

switch

known,

on the

the 0-1500

volt

pointer

as balancing

when the

the

"-DC

SET

SWITCH

connect tlte

measured.

to be

sets,

or B-

switch

greater

the highest,

DC

to the

reading obtained

If the

move the

range)

example.)

this

to obtain

scale.

a convenient

switch

a

IJse

only

for reading

is on

control

position,

volts

READ

SCALE

to bring

common learl

This

chassis is

the

must

side

-DC

to

the

than

(0-1500

position,

range switch

greatest

For

reading

the scales

DC voltages

scale

center

circuits.

either the

the

and

FROM

is the

isolated

be determined

or

tDC

voltage to

range.

volt)

then touch

than

is less

accuracy,

nearest

full

marked

between

position

zero

You may use

or

*DC

pointer to the

switch

MULTIPLY

READING

to the

chassis

as

be set the

rf

to the

scale

DC-

-DC

in tlre

BY

500 to

To

of the

side switch

to the

set

probe

voltage

ihe

(500

0 to.5V

1.5V

0 to

to

1.5 15V

5 to

50V

15 to

150V

to

50

500V

150to

1500V

measure

a range

to

highest

the

to

when

volts

5V

AC VOLTAGE

voltages

AC

voltage

to be

greater

(0-1500

"AC-OHMS"

measured.

be

to

on the

DC

.5V

1.5V 5V

15v

50v 150v 500v

1500v

with the

measured,

the voltage

than

volt) range.

position,

If the

0-1500

volt

0to5

1.5

0 to

0to5

1.5

0 to

0to5

0

1.5

to

0to5

0

1.5

to

MEASUREMENTS

VTVM,

set the

function

to be measured,

the

set

touch

then

reading

range)

connect

AC-OHMS,

obtained

move

switch to

probe

the

the common

is less

range

known.

if

DC

to the

and the

AC,

switch

than

switch

.L

I

1 10 10

100 100

1000

leatl

known,

ff not

on the test

side of

other

full

%

to the

to

range

scale

iower select without

is

the scales Read peak 2'83

times

that

when

meter

0-40

P-P

low

AC"

See

AC

and

Switch

IiMS

t]I]

50 to 150

500

position. the ra-nge

havingthe

highest

of

the meter

the

RMS

values

on the

the

a voltage

pointer

red

scale.

for AC

the

charts

RMS

in

VOL'TAGE MEASURED

0

to 1.5V

1.5

to

5V

5

to 15V

15

to 50V

150V

to 500V

to 1500V

(0-500

volt

which permits

pointer

RMS

AC

are

values

on

red

RMS

will

voltages

VOLTAGE

the

TO

scales

values

of 10

indicate

use

below,

probe

range

in

thi." exampie.)

you

to

scaie.

that

black

RMS

marked

within

obtain

to read

scales

"P-p".

for "*u-pl"

on the

scales

TO

go

off

voltage

calibrated

the

marked

of sine-rvave

volts

10 volts

the scale

that fall

indicating

MEASUREMENTS:

"AC-OHMS".

to

SET RANGE SWITCH

1.5V 5V

15V

50v

150V

500v

1500v

a-reading

It is

importani

can

be measur.ed

both

RMS

marked

peak-to-peiik

voltages

0-15

volt

"l.bv

to be

1.5

RMS low

usecl.

RMS,

these ranges.

5 RMS,

1.5 5 DC

1.5

5 DC

1.5

greatest

For

ne"arest

to remember

with

pe,,i-to-peak

an.l

"DC-RMS"

scale,

voltages

scales

to and 28.3

AC"

and the

is

applied

set Function

READ FITOM

SCALI]

LOW

AC

DC

or

RMS

or

RMS

DC

or

RMS

or II,MS

DC

or RMS

accuracy,

iutl your

u.rd. a're

the

and

switch

AC

scale

that

insirument,

always deflection 1500

v.fvM.

voltages.

peakito-

tn" are

equal

so

calibratecl

volts

on

..0-b.0V

to

MULTIPLY

READING

,.AC",

1

1 10 10

100 100

1000

volts

The

to

the the

RMS

BY

AC

PEAK-TO-PEAK

"AC",

to

T)EAK-TO-PDAK

TO BE

and

MI'ASURED

0to4V

4

to l4Y

14

to 40V

40

to 140V

140

to 400V

400

to 1400V

1400

to 4200V

Note sine-rvave both in

that

voltages

peak-to-peak

TV

receivers

Switch

VOL

"DC

the

are

of sine

VOLTAGE

in

the

or

RMS"

being

and

MEASUREMENTS:

probe

"AC-OHI\{S,'.

to

READINGS

SET

RANGE

SWITCH

TO

4V

14V

40v

140V

400v

1400v

4000v

scales

measured.

non-sine (complex)

are correct

The

IN

RED

COLOR

RI'AD

SCALE

4 P-P,

14

P-P,

40 P-P

140

40

140

40

peak-to-peak

for AC

,'oitag".

FROM

LOW

AC

LOW AC

P-P

scales

such

set

Function

voltages

"i.,

as are

switch

MULTIPLY

READING

I I I

1 10 10

100

only

l"

used

measured

BY

when

for

.Ihis

and

body sources

consequently

antl utmost

should

user

alligator

an

the voltage

to

reading the

while

vTVM is a

Iong unshielded

such radiation

of accuracy

reduce

when measuring

holding

avoid

clip or

point,

test voltage.

highly sensitive

wire hook

so that the

leads

test such as the accuracy

power

the test

of some kind

hands may

electronic

pick

up

lines,

of the

voltages

low

probe

in his

AC voltmeter,

voltage

AC

the meter

voltage lLeasurement.

in high hand. the end of the

on

be removed

and since radiations may indicate

impedance good practice

A

entirely from

the humarr

when near any

probe

pickup,

this

Therefore

circuits

is to use

tip to clip

the

for

the

probe

measure resistance

To

position,

reading probe probe

iZERO"

the

(infinity).

to

ohms scale, Set

OHMS''.

and the

near to

as

"AC-OHMS"

to the

and set the

tip

control.

.,OHMS

be measured,

Function

10000

ADJ."

Connect the

and

RESIS'TANCII

MENSUNIiD

BE

1000

.2 to

1000

to to

100000Oto1Meg

to

1 Meg

10 Meg

100 Meg

The

This

the

set

The

scale

The

apart from

accurate

portion voltages, lead them

to 100 Meg

to

needle should

is accomplished

pointer.

voltage markings

reading

low voltage

the

readings.

their characteristics

-rf those

[o inaccuracies

and to

RESISTANCE

range switch

Then disconnect

and multiply

Switch

O

10000

100000

10 Meg

1000 Meg

with the VTVM,

midscale as

meter

control

common

probe

the

"OHMS"

to

TO

O

READING

be set

(if

necessary)

on the

make

corresponcling

AC scales,

AC voltage

other

non-linearities

diode

The

if the

suitable

position

to a

possible.

position,

pointer

the

set the

to

test

tip to

proper

the

RANGD

SE'f

SWITCH

Rx1

Rx10

Rx100

R x 1000

Rx10K Rx100K RxlMeg

THE

to mechanical

RANGE

the

on

0-1.5

scales

rectifiers

in a

become

scale

meter

correction.

MEASUREMENTS

set the function

will result

that

the

attach

for the

and

AC-oHMS

the common

from

exactly full

to

to one side

clip

Read the resistance

side.

range being used.

Switch

set

then

ZERO on the ohms

to

alligator clip

pointer

lead alligator

the other

factor

position,

TO

NTETER SCALE

zero when the

by using

meter scale. RMS,

non-linear

prominent in the

were

the screwdriver

indicate

switch

0-5 RMS'

and separately

within

the instrument

region.

properly

not

and

metering

switch

in the

DC switch

alligator

scale

probe

the

scale, marked

in the

instrument

adjustment

corresponcling

the

4

P-P,

calibrated

inherently

rectifying

when

circuit

calibrated

"OHMS"

to the

by rotating

of the

probe

RDADING

meter

on the test

clip to

and use

tip

resistance

to

MULTIPLY

pointer

1

10

100

1000

10,000

100,000

1,000,000

turned

is

14 P-P

give

to

low

and would

to account

the the

"co"

the

on

"AC-

BY

oll.

zer<-r

to

lull

are sel

more

have a

AC

for

This does not apply to the DC

used.

scales, since in measuring

DC, no rectifiers

are

The face are colored measurements,

sinewave of voltage DC total of axrc.

relationship

Since impossible within between such complex waveform would established.

colored Range

RMS is an abbreviation

(direct

the

When we are

This relationship

there are almost an infinite number of rvaveforms

RMS and

just

to remind

current) voltage. P-P is an positive-going

between

RMS RMS is .353

and

measuring a

RMS. Peak. and Peak-to-Peak:

Peak Peak-to-Peak Peak-to-Peak is 2.83

1.41

is

.707 times

is valid, only

the scope of this manual

peak-to-peak

positions

Switch

"Root

oI

its

e{Iective or heating value, relating it

and negative-going

sinewave of voltage, there is a fixed mathematical

times RMS.

is 2

times

and their

you

that they indicate

Mean Square" which

abbreviation of

peak.

RMS.

times

peak.

peak-to-peali.

when we are dealing

when dealing with

have to be analyzed aird a

USING THE DECIBEL

corresponding scales on the

voltages relative to a zero

make

to

(Db)

peak-to-peak

term

is a

"Peak-to-peak",

with a sine-wave voltage.

other than

any statement

other than sinewaves; each

proper

SCALE

meter

AC

voltage

relating to a

to an equivalent

sinewave it is

of

or the

voltage

relationship relationship

'l.he

intensity

responds to doubled was tions. Normally, because detect. Manufacturers Db scale sponds to O.775

the reference level.

by injecting a signal of variable frequency and constant amplitude, with

connected to the output. such

ple.)

db above and below the reference freouencv level.

human

increase.

adopted. The bel corresponds very nearly to

this unit

uses

The

decibel represents

as 400

As

ear responds in a logarithmic manner to variations in

and not linearly-that is when the amount of sound is doubled,

it

so that we sense only a slight increase in loudness rather

.001

volt

cycles, for a convenient indication on the VTVM.

the input frequency is varied, the output variation may

of

A unit loudness signal levels are

represents

watt

For

loudness measure based on logarithms called

the smallest variation in sound intensity

use a variety of signal levels as a standard for zero

(1

milliwatt) into a

AC on

0-5 volt scale.

the

a voltage ratio, and it may be

example, a response curve may

Adjust

the signal

given

600

input

human ear response

the

in tenths

ohm

at some reference

of a bel, or decibels,

line

as zero db. This corre-

used

plotted

be

without

for an amplifier

(Zero

be obset

sound

the ear

than

the

vrrria-

the ear can

db. The

specifying

the VTVM

frequency,

db

for exam-

r',1

"bel"

a

in

CONVERSION CHART

FTJNC'I'ION SWII'CII S]''|'T'ING

F'ULL SCALE, VOLTS

RMS

IIOR RMS-P-T-P

NC

TO

VOLTS

PEAK TO PEAK

FULL SCALE, VOLTS

and DB

(Decibel)

DB TO BE ADDED

TO THE

SCALE READING

SCALES.

DB

1.5

b

15

50

150

500

1500

usiag other

When

true db

rection

Where R

negative,

the

values. The

which must

is the load in ohms. If R is

and must be subtracted from the db reading.

correction is added to the db reading.

than a 600 O load, a correction

chart below indicates some typically

be applied. A

db correction

LOAD, OHMS

9600 4800 2400

1200

600 500 300 250 150

50 15

8

3.2

4

1A

40

t40

400 1400 4000

generalized

=

greater

must be

than

for finding

R

600

If R is less than

(+)

equation

10 los'o 600

ADD TO

BTRACT FROM

DB READING

-15

-t2

-4

-3 0

+0.8

+3

+3.8

to

+10.8

+16 +18.8 +22.7

nuJ

directly

10 20 30 40 50

used

ohms,

OR

(-)

au

applied, to obtain

loads, and the

the correction

the factor

becomes

600 obmg,

cor'

is:

10

The

L2AU7

sets

up

the first

drop

or

read

zero.

upset

causing

across

the meter.

test

voltage

and

therefore

of

a vacuum the tube tube

can

The

imately megohms ance of

possible

it imum

disturbance.

100 microampere

twin

triode

in

a balance

grid,

difference

and not draw

maximum

1.5 volts. reduces

1 megohm,

to

between

potentials

the

potential

in

with

applied

r,oltage

a

a difference

The

to the

the

meter

tube

voltmeter

directly

is limited,

test voltage

A voltage

voltages

located

take measurements

CIRCUIT

meter

a balanced

meter

is

movement

the

two triodes

on

each

across

applied

in

the

will

grid

first

calibrated

circuit

to the meter.

the

meter

which is

divider higher in

the test

DESCRIPTION

bridge

potentials

then indicate.

is the voltages

movement

than 1.5

in

is connected

arrangement.

so that

plate

are

the meter,

to the first

on

and

the current

with

a linear

since

applied

network

volts.

probe,

is used

circuits

with

equal.

and consequently

grid,

the two

the

is

directly

having

plate

in the

The

zero

with zero

There

will

the

balanced

plates

The relationship

through

scale.

to be

amount of

electronically protected.

An

additional

in

R-F

the

one of

measured

to the L2AIJ7

a total resistance

the DC

components

circuit

adjust

voltage

and consequently

current

applied

be no

the meter

condition

between

meter

the advantages

are

applied

a vacuum

is

isolating

position,

with a min-

of

control

voltage

will

the

is linear

approx_

of

l0

resist-

making

a

to

is

to

AC measurements:

a DC

voltage proportional through bridge to read scales these low vrvM accuracy

volt

A voltage ranges ment

diode. on

of multiplier a voltage more

unknown to the input

meter scale

damage

the voltage

circuit

both

RMS

have

been

ranges.

on

the lower

that

ranges,

the highest For

rn

the full

divider

to limit

is

used

when measuring

measuring

divider

multiplier

resistor

grid

reading

"off"

the

in

transit.

D3

divider

causing

many

properly,

range,

resistances

the meter

and Peal<-to-Peak

especially

stray

AC

other

AC voltage

network

the voltage

it is

and then switch

resistances,

and

circuit

resistors

is then

of

the 12AU7

proportional

position

the meter

and

D4

to

the

network

to indicate.

calibrated

pickup

instruments

any

consisting

and proportional

reduces

ranges.

being

reduces

applied

possible

not

unknown

a 1.5 volt

the external

the resistance

balanced

to the

are used

applied

to

movement

AC.

to

the input

'alues.

to improve

the

with

this

do

not have.

measured

the voltage

the diode

to

voltage,

down

to a more

DC supply

resistance

of

the

l.s volt

to its resistance

bridge

unknown

to rectify

The DC

grid

The

AC voltage

The

0-1.5v

the

accuracy

special scale

In

is

applied

on

the

to a safe

apply more

always

is

to be

supply

under

test.

circuit

resistance.

is

automatically

the test

accuracy

the

0-500,

appropriate connected

which

voltages

voltages of

the

scales

and 0-5.0V

of

any highly

you

0-1.5,

to

the diode

and

level.

when

than

make it

measured.

in

series

The voltage

This

voltage

produces

shorted

providing

is

then

L2ALJ7

are

calibrated

RMS

of

the meter

have

improved

0-50,

and 0-1b0

0-1500

the instru-

150 volts

habit

a

range.

through

This forma

with one

across

is

to

applied

balanced

low

AC

on

sensitive

rectifier.

voltage

to the

to start

a series

or

the

supplied

an ohm-

preven,t

II

Your

VTVM is

would

yeara.

be

of several degree of care that

MAINTENANCE SUGGESTIONS

capable of

In order

in operation

given

any fine

continuous

for the user

and maintenance

piece

to fully realize

of

equipment.

daily

service requirements

should be accorded

these capabilities,

over a

your

period

the snme

instrument

c

a

This protection comnlon to the 120 VAC lf

ohms

the thc fuse continuity ohm-meter.

the

common

Should failure checked in

series with the ohmmeter

continuity directly with

following

The To

avoid clectric contained do so.

A

shock operating. Line voltagc power unit is connected

Disconnect

before servicins.

B&K-PRL.CISION

circuit.

test lead

protection

is in series

between

Replace

jack

with

in the

hazard

cord,

the

A I

and

power

with the with 1A

to

the

of the meter movement coil

another

SERVICE

instructions

shock, do not

operating instructions

present

is

on-off switch,

to ac

leads from

test

amp

chassis

line

or

fuse

is open,

the common

commr.tn

VTVM

ohmmeter if

another ohmmeter

whcn

(120

power.

Model

pigtail

ground.

other high

all

test lead

3AG fast

chassis.

you

test leads.

WARNINGS

for

are

the case is

VAC)

power

even

external

177VTVM

fuse

is connected

The

fuse

AC

functions

test 1ead.

and the vrvM

blow

first connect a 10K OHM limiting resistor

Remember:

without using a Iimiting resistance.

qualified

use by

perform

unlcss

removed

may

be

transformer, etc. any

if the switch

devices and from

is equipped

may

blow if the meteris

voltages

on1y.

be suspected, the continuity may be

while

of

the

Test for

The fuse

servicing

you

present

off.

is

internally

on

vrvM

open fuse

chassis

connects

-

NEVER

personnel

are

and the unit is

on

with

the ohms functions.

only.

other

than

qualified

the

the mcter

are affected

using

test meter coil

to

input

time the

aJusetl

between

connected

by measuring

a separate

directlv

ohms

the

since

from

Do not attempt

our standard warranty on

plastic

The charges of static electricity. This will cause erratic instrument is on or o{I. These static charges may of the commercially available anti-static solutions, or a solution of any dish washing detergent and the surface of the meter cover. The

Faulty operation of Check the continuity and

Another

VTVM,

the strings.

inability to obtain

resistance

cautionary measures in keeping troubles of

Symptoms

readings. Keep in mir-rd that

self-repair of the meter movement. This will automaticaily void

meter cover may through

frequent source of resulting

the VTVM.

repeated

wz:ter.

your

resistance

in failure of one or more

this difficulty may be slow, upscale drifting of the

of

proper-

zelo adjust action, ancl of course incorrect voltage or

the

use of

this

type at a minimum.

Dip a clean, soft cloth in the solution and wipe

cover need not

VTVM may be caused by open or shorted test leads.

periodically.

trouble arises from

patience

your

instrument

polishing

easily

be

precision

and the exercise of

are of the utmost importance

or cleaning

pointer

deflection whether

be removed by

removed

accidental

resistors in

for

improper usage of

this

the

L2

accumulate

good

proper pre-

the

one

using

liquid

operation.

multiplier

pointer,

in

IN

ALL MBN.I' CORI'. PARTN,IENT

FACTORY, PACKEI]

CAR'I'ON

for this

IS

SHOUI,D

IN

AND

IMI'oR'rAN'r

purpose.

CASES

SUSI'EC'I'ED,

ITECON{I,IFJND

TI.IE

WHERE

ITIRST

COXIPLI''|E

.,\

WF]I,L

ADDRI'SSDI)

NorE:

F:\UL'r'y

TI,IE

S]]RVIT]I]

BE

CONSUI,'1'EI].

ITETURN

INSI'RI]NIENT

P.\DDED,

1'O

DYNASCAN'S

'I'he

original

opIrRAl'ION

DEPAN,I'NIEN.I

SHOULD

OF

TI]E

S|RONG

packing

of

.r.Htr

orr

OIT

THE

SERVICtr

INSTRUMEN'I,TO SHOULD CORRUGATED

StrRVICE

the

BE

DEPARTN,fENT.

u'it

is

admir'blv

rNS.r.RU-

DYNASCAN

DE-

THB

CATTEFULLY

SHIPPIi{G

suitcd

IMPoRTANT:

ANY

WRITTEN METER INSTRUMENT. BER' THE NT]MBER

Your

major

MUST

IT

WILL

meter

repairs

before

If

repair, tion, mcnt. of strument

that

in

fa'lty test

INQUIRIES

INCLUDE

IF

YOU

BE

IN

ORDER

is

a reiatively

consulting

at an1'

timc

a CONIpLBTtr

as

notecl

The

Dvnascan

this

un.su:rily

operation

cquipment

NECESSARY

by

more

Corp_,

c:rn

be

description

exar't

COMPLETE

NEGLECT

TO

critical

the

this

meter

the

operator,

details

the

repaircd

of

detail

can

be

ancr/or

TO

THE

TO

FOR

ANALYZE and

delicate

Service

is

to

description

submitted

traced

improper

Departmcnt

be

MUST

more

quickly

and

returned.

suspectecl

due

to the

to

FACTORY

SERIAL INCLUDE THE

FACTORY

YOUR

instrument.

rcturnecr

of

suspected

n""ornpo.ry

to

the

Service

and

It

faulty

operation

ra"i

difficurties

analysis

tttnt

of results

REGARDING

NUMBER

THE

PROBLEM.

Do

of

Dynascan

to

the

factory

faulty

the

Department

efficienilv

is

very

important

in

nrany

in other

OF

SERIAL

TO

REQUEST

not

attempt

Corrroration.

for

opera_

instru-

the

in-

given

be

cases,

items

of

obtained.

YOUR YOUR NUM-

any

13

1.

Refer manual for

WARRANTY

to the

MAINTENANCE

adjustments

SERVICE

that

may be

section

applicable.

INSTRUCTIONS

your

of

B&K-Precision

instruction

2. If

lf contact to:

the

experiencing

or

double-packed). Enclose

name

and

B & K-Precision

your

list of

your

above-mentioned

your

with

address.

authorized service

authorized B & K-Precision

local distributor for

procedures

pack

unit,

a

letter

Deliver

to, or

the name

Service Department

B

& K-Precision Product

DYNASCAN

6460

West

Chicago, Illinois

do not

it securely

describing the problem

PREPAID (UPS

ship

agency

of

CORPORATION

Cortland Street

correct the

(preferably

(see

list enclosed

service

agencies

your

nearest service

Group

60635

problem

in the

original

and include

preferred)

with unit).

has

been misplaced,

agency, or write

to

you

the

are

carton

your

nearest

I4

LIMITED

ONE.YEAR

WARRANTY

DYNASCAN PRECISION workmanship

DYNASCAN

mmponent parts factory

receipt.

To enclosed Chicago, Illinois

Exclusions:

as

a result

defaced

DYNASCAN damages cnnsequential

This warranty gives you statc

to state.

Iior

may be warranty Department,

damage

product, and materials

servicc

department,

obtain

warranty

60635

This warranfy

of unauthorized

removed.

or

resulting

damages,

your

convenience

authorized

service

2815 west

in shipment.

will,

shall not

cannot

coRPoRATIoN

and

the

for

without

upon

delivery

accompanied

coverage,

registration

within

five

does not apply

alterations

be liable

from

loss

of use.

so

the above

specific

we

to make

repairs be obtained lrving

warrants

component parts

period

a

suggest

Park

ofone

charge,

repair

to an

authorizcd

by

product

this

card

to

DYNASCAN,

(5

days)

or repairs.

for

any consequential

Some

limitation

rights

and

you

or can

locally,

Road,

from

contact

chicago,

to

the original purchaser

thereof,

year

from

the

or

replace,

B

& K-PRECISION

proof

of thc

date

must

be registered

B

the

in

the event

states

exclusion

or

you

refer

please

& K-PRECISIoN,

date of

of misuse

It

is void

damages,

do not

may

also have

your

B

you

to

send

the unit

Illinois

wlti

be free

date

ofpurchase.

at its

option,

service

purchase

of

by completing

purchase.

abuse

or

if

the serial

including

all,ow

timitation

not

apply

other

rights

& K-pR.EclsloN

the

nearest

service

to B

& K-PRECISION

properly

60618,

that

from

defective

contractor

in the fbrm

and

plo.

nox

of the

number

w.ithout

of

incidentzrl

you.

to

which vary

distributor,

contractor.

packaged

its B

& K-

defects

product

or the

of a sales

mailing

35bgo,

product

is altered,

limitation

from

who

Service

to avoid

in

or

the

or

If

--

trlYNASCAN

CORPORATION

480.086-9-001H

West Cortland

5460

Chicago,

@

1979 O DYNASCAN CORP.

Illinois 60635

Street

PRINTED IN

U.S.A.

I

rl

I

l

MODEL

L77IV95

PARTS

LIST

SCHE'\AATIC

SYMBOT

c-1

c-2 c-3 c-4

c-5

c-6

R-2, R-4 Ii-3

It.-5

t{,-t)

tt-7

R_B

R-9

ti- 19

It-20

R-21

40

r)

It 2il

17-24

It-25

R-26

P.-27 R-28 R-29 R-30 R-31 R-32 R-33 R-34

B &

DYNASCAN

CAPACITORS

DESCRIPTION

10 Mfd.

Mfd.

.02

IUfd.

.02 .02 Mfd. disc ceramic 1500 Pfd.

1600

50K ohm 10K

100K

10K olrm 900K ohm ll04K

140K

12.7 olrm

1]0 900 olrm

gli

olrrn

9()I{ ohm

90{)K ohm 9 nrcgohm

10K 20K ohm ?0K ohm 200K 700K ohm 2 megohm

megohm

7

1

megohm

ohm

36

175 volt

@

400 volt

1600 volt

dual ceramic

Mfd.

@

20Tolinear

ohm 2O%

ohm 20To

2\Tolinear

I

ohm

\/2watt

ohm

12

lwattLTo

ohm

r/2watt

r/2wittt l,!

watt

l':

r,/2watt

12

ohm

/z 1/zwaIt

12watt

1/2

ohm

Yzwatt

12 L/2

Yz

watt 1Vo

2

electrolytic

207o

207o tubular

10 volt electrolytic

RESISTORS

linear taper

taper

watt I7o deposited

l/a deposited

vratt 1/o

resistor

1.o/o deposited

17.6 deposited 192, tleposited

192, deposited

u'att

19lo depositcd 1% dcposited

watt

17o deposited

watt

1% deposited 1% deposited

1/6 deposited

watt

17o deposited 1% deposited

watt

1% deposited

watt

17o deposited

watt

resistor,

K otvtstol

CORPORATION

4a8-O66-9-OO2E

tubular

GMV

disc

-

CO]TTROT,S

(twist prong) '....008-060

pot.

taper

(twist prong) .....008-060-9-002

pot.

carbon

deposited

carbon

resistor

carbon

carbon carbon

carbon

carbon resistor carbon resistor carb<;n resistor

carbon

carbon resistor

carbon carbon resistor carbon carbon

metal fiIm

resistor

resistor resistor

resistor

resistor resistor

DYNASCAN

PART

.021-003-9-007

. . .

.. .026-'{01-?-203

..

. .026'162'7'2A3

. .

.....020-501-7-203

'035-501-0-152

.

. . '022-001-9'013

.008-001-9-030

. .

'008-001-9-0:9

...

.002-001-3-904

. . .

...004-076-9-001

. . .002-102-3-14

.......004-074-9-001

......002-102-3-900

......002-102-391:11

......

.002-702-3'9(t2

......

' ' . ' .

..

.

.....002-102-3-f,03

...002-102-3-904 . . .002-102-3'905

.002-102-3-103

. . .

....002-102-3-203

'002-102-3-703

...

. '002-102-3-204

. .. '002-102-3-704 ' ' .002-L02-3-2Os

.002-102-3-705

. .

.002-102-3-105

' .

.

. .004-075-9-001

. .

No.

9-00:l

I

3-74

cofrrPoslTE

499-02r-9-00rc

IUiCil0i

wtttt

tt0iI

"1 r -

'?

J

II

ll lr: l

€,\:r(

lT'1

L

.-(A

\/

Ltttl

:

rr

ll

U/Y

ytlli0

50-c0,l,

o26i ?

orFl

l0 t(

L

?t4v

50

irlttc

.-1:")

\r

601"

) Ll

, t,,

Lm.r

lc 0c

?rc,1-

lstvc)

|

yrYf

-r

Ptort

)

-r^rirrrrc,l,o*

--

n.3

rl

l) \!

'

iC 5 )41-

0015

ilttltt

(rl

-*.:

.

{,,*-..--

il\

tl0tI

rtlt

l^rct

swrrcx

sr|lcN

turcil0r srIcN swrlcr

sttlCxts rr0t SlllTCHtS llltttD

t. l0O0 rrc' ^tt

cltlc[0ts tlSl Llll

st0wr

stQUttct

srQuttct ort/rirrsrr

tAlttto

tr0

1000 m0

I

lo-19 rr

C

I

o,1

of

1'_

.:

fts

ftotl

tr 5v-oc toslilol

_0c

5Y

-lrl

l5Y

-Ir

5

t

15v_trn

50

| - lrD

150

lrlooaO

t-

500r-

1500f-lrlllG

sH0wt

||

lc

+0c

0ltr5

Il0lI vltItD

ttlt

rtc

|l

lfii

lrrr

lt

lrlml

0il

yttwt0

p0slil0t

tlol

Il0r

rrtl

li-'

iil

_jI

crr

-crr

:

DIODES

SCHEMATIC SYMBOI.

D-1,D-2,D-3,D-4

v-2

SWA SWB

I2AU7

Rangeswitch Function ewitch

117 volt

717-234 volt Meter. AC/DC

Neon with

L,iae cord Black lnstruction Knob Knob without indicator

DESCRIPTION

1 Amp

600 PIV

silicon

SWITCHES

.

MISCELLANEOUS

60 cycles transformer

50-60 cycles

Assembiy

Probe

100K ohrn resistor

lead assembly

test

Manual

w/indicator line

line ...

TUBES

transformer

...

..

DYNASCAN

PART No.

. .151-018-9-001

.

..232-120-l-2L7

...

......083-070-9'001

..083-110-9-001

.. .. .065-041-9-001

....065-041

....523-059-9-001

. . '.....PR43

. ' . . .401-001-9-002

. .420-001-9-009

.

. .539-002-0-000

... '...480-086-9-001

.. '..751-040-9'001

....751-041-9-003

9-002

I\{inimum Advance

SPECIFY

AV-1A

AV-2A

charge

remittance

SERIAL

R.F. High

per

S5.00

mugt

Nlodel

Probe extends

Voltage Probe

invoice.

cover

WHEN

#

177lV95

Electronic Parts

prices

Parts

postage

or express charges.

OI]DERING REPLACEMENT PARTS

Accessories

250

to

range

will be furnished upon

Available

Distributors

MC

from

Your

request.

BK Precision 177/V-95 User manual

Specifications and Main Features

Frequently Asked Questions

User Manual