Collins Selective and Wideband Voltmeter 476J-1 Manual 523 0276 00, Revised 15 June 1961

7/24/2019 Collins Selective and Wideband Voltmeter 476J-1 Manual 523 0276 00, Revised 15 June 1961.

1/47

J

INSTRUCTION BOOK

SELE TIVE AND

WIDEBAND VOLTMETER

476J l

COLLINS

R DIO

COMP NY

-

WCC


2/47

4 .Rev.

2 ~ 2

(C)

GU R NTEE

The equipment

described herein

is sold undu the following b'1J:uatllee:

Collins agrHos

to

repair

Or r e p t a c ~ . without ch.lrge,any eCflJipment, parts, Or accessories which

are

de

flJ'Crive as t.o design, wo.kmllllship

Or

matetlal, and which

returned

to Collins at

its

faclOf:'l'J transportation

prepaid,

p r 6 v i d e d ~

fa) Notice

or

th,e claimed defect is given CoHins wilMn one (1) ye'af from clat-e oi deUvery and goods u

ret!ii f'necl in a cco rdance

with

Co Ili.ns'

inst ructions

.

(b) ECI'Jipml.mt,

3 . c c e s S D r l ~ g ,

tubes, and

battfll"ies

not

manufactured

by

Collins Ot

frolll Collins'

designs,

aH

subject to only such adjustm.ents as

Collins may

obtain

from the

supplier

thereof,

{C} No equipm.ent or access-o.ry shall.

b@ aeem,ed

to

be defective if"

due lO exposuJ:1!

or

excesslve moisture

in the a tmos

phe

re

or

(jIhe rwise aite r

deli

...err,

it shall

(aU

to,

ope ratt' In

3

nOrmalor p.roper :manlle r ,

Collins fUl"Lher

gtlaraolees

lhatany radio

trall.SmHter e s ~ r i b e d h e . r e l n

will deliver full

1'1ldlQ

~ u e n ~ y

power

outpul at lhe antel'lna lead when

connecled

to a suitable

load,

bu.t such guarantee 5haU not be COI15lrued as a

guar:anl,e'e

of any

d ~ n n i t e co.'erage r range o[

sajd

apparatLls,

The'

guarantee

of t h ~ s e paragraphs

is

void IJ

~ q u ~ p m e n ~ is altered

or repaired by others than

Collins

Or its

authorized

se:rvlce

center.

No

warranties.

expressed

or

1mplted, shall be

applicable

to

any eql.npment

sold hereunder

I

and the

for@going

shall

c()!lslHute tile

Buytr's

sole

right

and

remed.y

under

tile agreemellts

in

this

puagraph

contajn.ed.

rn nO e-venl s.ball Coning have an}' liabili.ty for eonse


3/47

INSTRUCTiON BOOK

SELECTIVE

AND

WIDEBAND VOLTMETER

76J l

23

0276

DO

IS Seple

m

b er

9:5

9

6h576

REVISED:

15 June 1961

COLLINS

RADIO

COMPANY

DALLAS, IEX.AS, U S. A

. .

1961

~ I t l T n ~ L t l

u n u Of

AMERKA === ' '======.

~ ~ C ~ ~ I N i j L E i i

N

tHI

T BLE OF CONTENTS

SectiOIl

Page

I GIN

J RAL

DESCRIPTION

. .

1

1.1

General

. . . _

1

1.2 Equipment Description

1

1.3

U

D It Characteristl

cs .

1

1.3.1 Phys

leal

Character istie

S

1

1.3.2

p ~ r t i n g

Cha

racter isUes

t

1.3 3

Electr ical aracte r istics

1

JNST

ALLATION

3

2 1

General

3

2.2 Unpackir g the EC{ulpment 3

2.3

Installation . . .

3

2.4 Initial Adjustments.

3

2.4.1

P

r

mary

Power

. 3

2.4 .2

djustments

3

OPERATION

4

3 1

General

4

3 2

Controls

4

3 3

Calibration 4

i


4/47

v

Ta 01 C O l 1 t c l ~ t s .

List

0 lu

stnI.i

on.'"

TABLE

OF

CONTENTS CONT)

Page

III (ConL)

$.4

VTVM

),.

e:1

u r e m ~ l : t s

('wuleband)

3.4 .1

R ~ [ S Ll;yel

3 '.2

Voltage

R-

t.UJ;

5

3.5 Selective Vol meter

M E ' ~

: ; t 1 r e m ~ n ~ ...

5

3.5.1

Harmonic

Distortio"

Measurement

5

'3.502

IltermoctuL.1.tio \ .

@ a s u r ~ m ~ l l t . s

6

.3

Cruss a. It . . I ~ fJurcmen 6

3,,5,.:

Attenu, tint j Mea .. "ell elJLs .

7

3,5.5

lQd f. iOB c:

a tlcte'ristlcs

Te:ltm,e er 4 76 J-1

tV

1-2

Cal l'ying Case t'or S e l l : c t t l , ' ~ and ..dcbnnd Voltml?te,. 476J-1

LV

2-1

Three :Prong Line C


5/47

. ~ ~ ~ r j

4-1 S-electi ve

and

W

ideband

Voltmeter 476J

-1 Block

Diagram

.

8

fi-l

Selective

and

Wideband Voltmeter 476J -1 Calibration

Equipment

Assembly 9

5-2

Selecti

ve

and, W

ideband Voltmete

r

476J

-1

r S{:h,e-mati

c D

iagr-am

.

15/16

6-1

Seledive

ami

Wideband

Voltmeter

476.1-1, Parts

IdentiHcation.

7

LIST OF TABLES

Table

Page

1

D-C

and

A

C Voltage:

Check

11

2

T rouble

shooting

Guide

11


6/47

Section I

General

Description

MAIN TUNING

FUNCTION

SELECTOR

CI31

CI32 51 5

MIOI

RI 9

RI5

51 1

KI8

EIOI

858 8 Pb

E 1 2 EI 3

SI 2

SI 3

JIOI

SI 6

SI 4

Figure

1 1. Selective and Wideband Voltmeter 476J 1

838876 Pb

Figure 1 2.

arrying

ase for

Selective arid Wideband

Voltmeter

476J 1

iv


7/47

Section I

General Description

SECTION

I

GEN ERAL DESCR IPIION

1.1

GENERAl.

'.

Selective and Wideband Voltmeter 476.J-l

is

a 'sensi

tive

test instrument which measures the voltage level

01 signals in

the

4- to

750-kc range.

As a

selective

vOltmeter, i t

measures

(1) harmOniC

distortion, (2) intermoduiation products, {3}

t : r O S s ~

talk,

and t4) modulation characteristics (relative

to

eledrical

filters, cables,

or

openwire

linea).

Th e

~ - -

selective voltmeter can be used also to determine the

lrequencies

or a

complex waveform.

As

a

wideband electronic voltmeter, the

476.J-I

me a

sure

s the r

ma

YOl tage

of

a S

ingl

e

Or

compos

i te

sigruJ1

Or

noise

i.n

the 200-cps

to

750-kc range.

1.2 EQU IPMENT DESCR.PTION

Tbe

4

76J I

consists

of four major circuits: (I) an

r

w f

a mpliUe

wi th an

input rnatching net

wo r

k and a

low-pass rmer, (:2) an

800-kc

i-I circuiL (3) a 15-kc

1-

f

ci r cuit, and (4) a mete r ed output

cll'

cuit.

The 476J-I is

a

single

unit wnic:h

can

be

either rack

mounted

on

a

standard

19- inch rack Or

uaeo on

9;

bench (see figure

I-I). It

is

fitted

v.1th removable

safety

covers

and two carrying handles,

A

c i n f . o c ~ d

wood.en carrying case

is

available for ~ r a n s p o r t i n g

the unit. See figure 1-2.

Buss wire

and terminal

boards

are u s ~ d

on

internal

wiring with

small parts accessible

on

composition

terminal b o a r d ~ C

t'

[Heal clrcuits

are

enclosed

in

metal

cOntainPol

S

wh i ch ha

Vi?

r emm'2.b1e

cover 5

Tube s

are

held in place by spring.loaded holders. The

tuntflg

capacitor is

r u g g e d i ~ e d vernier-driven, and

dirtly

calibrated with the

tunlilg

dillI, The di.al is

illuminated witb two 6

.3-volt

a-c

pilot

lamps.

1.3

UNIT

CHARACTERISTICS

1.3.1 PHYSrCA Ir CHARACT ERTS I'ICS

weight Without

Case:

59 pound.s

Weight With Case:

78 pounds

Size:

19 by

101/2

by 12 inches

Forward

Projection

(..men

rack

DlOunted);

2-1/4

inches

Mounting;

Rack. mounted Or

portable

Ftn1..sh:

Chrome plate

and tin

plate

chassiS

Grey panel

Ventilation:

Convection

1.3.2 OPERATING CHARACTERISTICS

Ambient

Temperature:

-10C (14F)

to

!WC (122F)

Ambient Relati ve

Humidity:

o to 9'5

percent

Maximum

Altitude:

1 ~ O O O feet above msl

Operating

Duty Cycle:

lnte

r m ittent,

attended

1.3.3 ELECTRICAL CHARACTERISTTCS

Voltage

RequIrements:

110 volts a-c, 42-60 c:p.s

or,

220 volts

a-c, 42-60

cps

50 "oU-amperes (apprOAimately)

Input Impedance:

Balanced

Selectable-at 75-) SO-6DD2K. Minimum return

loss, 20 db for

the

7515D-600-ohm positions.

Unbalanced

Selo:ctable

at

75-150-60D-20K5K.

Minimum

return

10.$$,

20 db

for

th

e 75

150

-600-

ohm

positions. ApprOXimately 60 uuf shunt

capaci

tance. .

Ma;'l:;lmum Input

Voltage:

Balmlc:ed

10 volts

Unbalanced

10

volts for

75

-150

- 600- ohm positionl::i

100

volts fOr

20K-5K-ohm posi.Uons (:>aD-volt

d-

c

blocking,

maximum)

1


8/47

Section

Gerler:d DC:5cl'ip

ton

y..Iea u r e m ~ l I t CJ1;H.rc:ent.!;3 eycle8

Errol' lI. 50 kc (Mh!r l.diHlIrat 0,1 ::It Odb

.1:5 pe c ~ , t

of

full st'. e d e n e c t ~ o J .

Varl:t

Ion

Wi

h. Lhe d}'nam' c atteI'l1,la or n u

ges

:::0.3 b i'rom 0 db to -60

db

(n .e-asurp.Q

at.

o on the

'cae)

Vru'iatl

nns wi1.h t.le

fre uenq

.l'cfe_

(3.{j

to 50 kc

1 ,G db

( w l t h t h ~ '.1

plJt P3d

().)

POSitiOL a dh)

Error

for 10 PC l co eJ'\t

line

,,'.;:Iltac:,e varia1.i.ons

.!=O.5 db

Ba.'ldwidth (at 3 db)

2QQ

t;}T

C s ~ p p 1 f l x t m a 1 . c l y

SelecLl 'ity

"orp. thaI!

75

db down for F

ooa

c y c l ~ s

o

Harmonic dl8tort lo l l

(2nd

amI 3rcl harnonlc

se"aratf!ly)

Morc 1

a

'10 db do '11

In er

odulatLoH distor on

(2ml

S . ari'lte1y)

More thaH

70 ell)

O','ffi

Ifl

rst

in1.crmdiate-fr,

Oil]

ucy

atteI

uatiuTI lHOD

kd

Appt'oxlmllLtely 30

db

First 1".onve&'aion

ma"'

atleu atiollS (1604 to

2350 kc)

MOr'G

thall

30 d'

S@eond

cooV'cI'slon ImaKe

attenuation (signa:.

que

ley

::m kr:)

M (H' ethan 90

db

OUlcr spuriouF: gigJ als. ,1tlenu:a.tiotl.

lila

70 db

r.!ferl'cc! to the

high

81.

oS'

aJ

und..:

t ~ F : t

Sac.kground

n o ~ s c

l.ess tl an the ftr.sit

1.Isc'fu1

meter sc le

di .'Is-ion

Lc-vd cali!)", '.lon

o

de

ie-veol:: . 50 kt:

Frequency

r.alibntt.ion

Ev 3,'

50

_'C (us'

g:

a

headset)

DHec.tor

A V w r ~ . l g e ;,;:ah@

ype,

cal'b o ed in

roo,t @an

Sqtl,H't';

iur :,tin cid3. waves

Di'l'I.

ions on' e

.I: scale

0,2 db frol:U db

to

-4 db

a.s db fro -4 db to

-10 d

0.02

volL

'.rOD. 0.1 tu

1

'011.

0.1 va"

from

O,S to 3 nIts

A


9/47

"-..-.

Section

11

In

staUa t

lon

SECTION II

INSTALLAT ION

2 1

GE

N ERAL

Section II outlines the

procedures

for

unpacking,

in

stalling appl}' ing

pr i

mar y power! al

:< :

lnit) II Y

adiusting and calibrating the 0.(!.lipmenL

'2.2 UNPACK I NG TH E EQU IPM ENT

U[lpack the equipment carefully. In6pect

each

com

ponent for physical damage. Check

mec.hanical

operations 01 the switches and tuning controls. I f

defects

are

found, reler to the IJlside tront cover

of this publication for pl"ovlsional guarantees and

s h i p p i n ~

instructions.

l a c ~

spare parto

kll

either in the car rying calle c o v ~ r cabinet or a suitable

parts

storage

location,

2 .3 'NSTALLATIO.N

c m o v ~ the pl'"otecti ve

covers

by loosen ing the knuded

screws.

Remove

all shipping documents

and

packing:

SECTION &I,-1Jo

material

from the instrument. Secure all tubes

in

the sockets. Check the pilot lamps On each side of

the

dial RoSsembly.

Replace the

co\'ers.

Check

luses

on rear or unit. .

2 4 IN ITI

AL ADJUSTMENTS

2.4.1

PRIMARY

POWER. Attach

the

l1ne

cord

con

nector (,figure 2-1) to l"ecessed rnale

i:lput connector

P 10J on the rear

chassis. Check

the pri mary power

selector on the

rear

of the

untt

to

ensure that proper

a-c operating voltages are

applied

to

the power

tran sform er .

2.4,2

ADJUSTMEN"TS.

Follow

the

procedure out

llned in paragraph

3.3,

CA LlBRATION, of Section Ill,

OP T ION>

for th

e In ltLal adj ustments and calibr

a

tion of Ute unit.

f t h e s e p r o c ~ d u r e s i n d i c a t e equipment

malfunction, fonow t1w maintenance

procedures out

lined in p r ~ p h 5.4, Section V.

FLgurc

2-1,

Three Prong Line Cord

Connector

3


10/47

1

Section m

Operation

SECTION I I I

OPER TION

3 1

GEN

ERAL

The following

paragraphs

outline the p r o ~ e d u r e s for

calibrating the 476J-1

and

m.a.king

specific measure

ments. Refer to figure 1-1 and

paragraph

3.2 for

identification oi

controls.

3 2 CONTROLS

Test ad]u,atmellts

a

re

made fr(lln

the iront oi

the unit.

Silk

screened labels

idE:;tltify

the controls and

the

, .lues

of

each switch position. There are

l ive

rotary

ganged

waler

sWitcbes, three

potentiometers,

and

two

variable

capa.Cit.otB.

L

INPUT IMPEDANCE switch

S10 I

is a

double

pole, 9-position, 3-1,Ir,3jer-,

rotarysW1tch,

which changes

the .

nput impedan

c

c

2. INPUT

attenuatiOn

swib::h

8102

is a double-pole,

. 10-position, rotar.' 3W1 ch, which switches In

L-pad

fLttenuators

to littenuale the signal.

3, FREQ

RANGE

switch SIOS is

a

double-pole

6-pos i

tion,

roL tI'y

switch, \Vb

i

ch

s ~ l e c t s th e correct

LC combination

for

the

selected frequency

range.

4, SELECTIVE VOLTME'l'ER

RANGE

switch S104

is a single-pole, a-position, rotary 5wilch,

which

switches

in

series resistance,

5

..

Function

Sel,ector

switch SlO5 1s a double-pole,

6-position, 3-' ...

afer,

f'otary switch whlch selects the

mode

of operation.

6.

AD.J

WPUT potentiometeI: R109 is located

In

the

upper

left

COrner

which,

i f switched

in

by lJIWUT

IM P

EDANCE

switch

S

10

1, allows the lnput

lev eJ

to

reach

posiUon "0 db"

on

the

m-eter as reierence

vol

tage. t is used

only for

measurement of volllige 'ratios,

7. CAL 1

potentiometer

R

1130

is

located

below

th

e

meter; it varies the output

01

the 50-kc osclHator.

8,

CAL

2

p o t ~ n t 1 m e t e r HISS

1s located just to

tlu } right

of CAL 1;

it

calibrates

the ampliiier sections

used in

the

selective-vQltmetel' application.

9.

Vernier-dri'len

variable

capacitor C

1:,1

1

MAl '>

TUNING knob is located Hoa r the dIal and 1s a broad

tuning C,Ol.ltrol.

10. DIAL CAL tr immer capadlor

C132

polntel'

knob

is located to the right of lhe

MAIN TUNING

control

and

is us

ed for

ca.1ibr

ating

th e dL.'l1

to

e

xaet

freql l.(mcies.

4

3 3 CALIBRATION

Follow

the steps

below in the proper sequences before

attempting

voltage m e a s u r ~ n \ e n t 6

L Connect

the line cord to an a - c ret :epta

e

and

turn the

t o g ~ e

switch

on tnt;

front panel to

the

ON

positton. Allow

the

unit 5 minutes

for

stabilizatlon,

Th

e

tran

s fOTme

1

primary

voltage se

1

eetor

on rear of chassiG must be

in

pl'oper

position to match

;\-c source

voltage.

2. Turn func:tion selector

switch

S105

to

the CAL 1

.position.

3, Adjust CAL 1 potentiometer Ri8{) for an

indi

cation of

0 db as

shown

by

meter

M10 L

4. Set INPUT

switch

5102. SELECTIVE VOLT

MET

ER

RA KGE

swltch SlQ4, and

function selector

switch

8105

to

the CAL

2 position.

5.

Turn

FREQ R N ~ switch 8103 to the 1

5

60

position

and the

tuning dial

to

the 50-kc position.

6,

Adjust the DIAL CAL control C132 until the

meter

indicates

maximum

deflection.

7 Adjust

CAL

2 potentiometer R156 for 0 db on

meter M10I.

8 Reset the dial to the appropr atetest frequeney

and the

switches

to the test

positions,

as specilied

in

the

follov.ing paragraphs,

The instnlment La now caliibra'ted{or normal

meas

urements,

f

an a,ccurate

frequency scale calibration

is necessary:

1.

Connect

a

headset

to

ja.ck

JIO

1

marked

PHONES.

2,

Reset function

s e l ~ c t o r switch

S105 to the 50

XC

XTAL

position.

3. the

dial

to lhe red

mar.k ncar@\St

the test

freqoenc

y .

4.

Adjust

DIAL CAL

control

C13a until

a

zero

bea

t is

hea.rd

in

the

headset,

5,

Reset the dial

to the

test requencyand set

function selector switch

S105

to

the SEL VM }XJsiUon.


11/47

Section

m

Operation

3 4 VTV MEASUREMENTS WIDEILl N D)

The 4 76 J - 1

measures

single

or

composite signal

r

ms voltages Or voltage ratios

(in

db) over the

200-cps

to

750-kc

spectrum when switch

Sl05 is

set

In the VTVM position. The m.easurement.s can be

made

on

either balanced 0 r unbalanced

2-

conductor

circ;uits.

NOT

Compare the output impedance of the

c

t r

cui

t under te

st

with

the value

indi

cated

by

INPUT

IMPEDANCE

swltcb

S101. The

two values should be lhe same. For very

low

level mea sur ements,

th

e input leads

should be

kept as short as possible,

Check

all

ground connections carefully.

3.4,1

RMS

LEVELS. Follow

the steps

below

when

malting' vtvm measurements.

1.

CaUbrate

the

meter

as

instructed In

p ~ r ~ -

graph 3.3.

2. Set

~ P U T

IMPEDANCE sw'rtch S101 to the

correct position to

match

th circuit under test.

3. Set INPUT switch

Sl02

to the XI0

s c ~ l e and

{WlctiOn

seledor switch

8105 to

the

VTVM

position.

4. Connect the circuit being

tested to

input term

inals

E101 and E1Q2 with the center conc:\uctor

or

ungr

ounded lead

attached

to terminal E

10

1.

5.

Adjust

U\'PUl' switch 8102

for an

on-sc:l.le

m ~ t e r indicatiOn,

and

record the indicatecl. voltage

(rms).

3.4.2 VOLTAGE RATIOS.

Follow

this procedure

when comparing the vollagG

ratios of two 01' mare

signals in succession.

1. Set

INPUT lMPEDANCE switcn

S101

to

the

position a.rad function

selector

switch S105 to

!he VTVM

position.

NOH

This

operation fixes

the

input

resismnce

of the unit

at

5,000 ohms (non inductive)

and provides

a means 01 calibrating

meter

MlO 1 to accurately measure

voltage

ratlos

of

different

input

levels.

2.

Apply

the

signal

which has

the

highest level

of the

Signals

being

tested

to

terminals E10I

and

E102.

,j

3, Set

INPUT

switch S102

to

the Q-db position

and

luxn ADJ TNPU'T control

RI09

for a meter

M101

inw

catiOn of 0 db (0.775v).

4. RemO O e the

reference

voltage

{step

2)

and

individually

measure the

remaining levels On

the

test

circuit.

INPUT

switch Sl02 can be adjusted to

maintain on-scale

meter readings

as f)eCessary.

TO compute

ilie level

indicated

by the instrument:

1. Record the metElr Indica.tion in db.

2. Note

the

position

of

Il\: PUT

.swjtch

5102 and

SELECTIVE

VOLTMETER

RANGE

switch 8104.

3. Add

the

meter indication and the two

switch

indi

cations

algebraically

to arrh 'e at the total level in db:

Le., value in

db;;;:

-4(meter)-20(St02)-10(Sl04) '= -34

db.

3.5 SELE TIVE VOL

TMTER

ME SUREMENTS

The 4

76J

-1

me a

sure

s har monic distortion, inter mod

ulation prodm:ts,

crosstalk, attenu.1.tion,

and modu

lation characteristics ",,'hen

used

in

the

selective

voltmeter application. The following paragraphs

describe

these

measurements.

Calibrale the

meter

as lnstructed

in

paragraph

3.3

and

perlonn

the meas

urements

in paragraph 3.4,1,

sleps

1 to 5 b e f o r ~

attempting selective

voltmeter

measurements.

The

latter ensures that input levels

will not

overload the

instrument.

instrument h

harmonic

levels.

Use

the

test equipment

setup

shown in

figure

3-1

and

follow the

steJls

below in

sequence.

1.

Perform

steps 1

and

2 i paragraph

9.4.1.

2.

Set function

selector

switch

B105

to

the

SL

VM

position.

3. Connect the output

terminals

of the netwo

k

under

test to

input terminals E 101

and EI02

on the

476J - 1

and

tun e MAIN' TUNrnG control C131

to

til,e

f u n d r n e n t l i r e ~ u e n c y

4. Set lNPUT switch 8102 to til o2.D-db position

and SELECTIV E VO LTMETER

RANG

: switch S104

to

the O-db position.

5. Increase the signal generator output tOl" a full

scale cl.ellection.

Record

the level.

5


12/47

Sectllo i l l

Operation

r -

;:p :l

I

ILTUl

I

I

:

-

I :

I

I I

I

L

.:

-.::-:.::,-= l

t O P T I O N ~ L 1

- r E n M I ~ ~ ~

NETWORK

\ J ~ O E ~

TEST

:; 4

>

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Documents

Collins Selective and Wideband Voltmeter 476J-1 Manual 523 0276 00, Revised 15 June 1961