General 1381 User Manual

INSTRUCT

TYPE 1381

ION

MANUAL

RANDOM-NOISE GENERATOR

2Hz-

50kHz

GENERAL

A

RADIO

COMPANY

INSTRUCT

ION

MANUAL

TYPE 1381

RANDOM-NOISE GENERATOR

NOTE:

convenience

This instrument is equipped with

and

2Hz-

Form No. 1381-0100-A

ID No. 2495

April, 1968

safety.

Refer to

50kHz

our

the

new snap

Service

..

on

Section

knob for added

for

details.

GENERAl

WEST

Copyright

West

CONCORD,

1968 by

Concord,

General

Massachusetts,

R A D

MASSACHUSETTS,

Radio

0

Company

USA

COMPANY

USA

Specifications

Spectrum: 2

Hz

to

(3-dB-down

slope

is

12

Waveform:

sity

function

the

noise

on

the

indicated

Voltage

0

±0" ±20" ±30" ±40"

a

1s

the

Clipping:

Flat

half

of

point

dB

Table

and

generator,

standard

The

(constant

upper

cutoff

can

be

per

octave.

below

specifications

as

measured

values:

Gaussian Prob.

Dens. Function

0.0796

0.0484

0.0108

0.000898

0.0000274

deviation

noise

can

energy

frequency.

switched

shows

or

rms

be

clipped

per

cycle

to

2,

5,

values

of

on

amplitude

In a "window"

Amplitude

1381 Random-Noise Gen.

of

value

of

internally

bandwidth)

Upper

or

50

Gaussian

density

0.0796

0,0484

0.0108

0.000898

0.0000274

the

notse

to

cutoff

kHz.

probability

distribution

or

0.20,

Density

±,0.005

±0.005

±0.003

±0.0002

±0.00002

voltage.

remove

±1 dEl

frequency

Upper

centered

Dist.

the

from

cutoff

den--

occa-

of

slana!

wide

to

approximately

on

the

spectrum

Output

Voltage:

3V,

rms,

Spectral 40,

and

2,

5,

or

50

Output

Impedance:

ing

distortion.

Amplitude from

full

Power

Required:

400Hz.

Weight:

NetShipping-8 lb

General

extremes

for

Level:

13

mV

kHz,

Control:

output

Radio

2,

or

the

Maximum

any

bandwidth.

At in a 1-Hz respectively.

to

approximately

6W

5

Jb

(2.3

Experimenter

of

amplitude.

3,

4,

rms

3V

output,

600

Output

at

kg)

{3.8

or

bandwidth

ohms,

100

Clipping,

5G.

such

spectral

for

unbalanced,

amplitude

60

dB

to

125

clipping

V,

amplitude.

open~circult

kg)

Reference:

output

level

upper

shortable

is

continously

below

or

Vol.

if

desired,

Is

negligible

voltage

frequencies

without

leveL

to

250

No.

1,

adjustable

effect

is

at

adjustable

V,

Jan,

has

is

approximate~y

cutoff

that

200

42,

least

64,

caus-

50

1968

of

to

Section

Type

1381

Random-Noise

1-lntroduction

..

._

4 5

Figure

1~1.

Generator

(2Hz

to

50

kHz).

1.

1 PURPOSE.

The

Type

1381

provides a

nals.

This type

high

Random-Noise Generator I Figure

level

of electrical noise

of

signal

is

useful in room-acoustics studies,

at

its

output

1-1)

termi-

loudspeaker and microphone tests, psychoacoustic tests, filter

tests, crosstalk measurements, calibration checks

on

recording

systems, modulation of signal generators and test oscillators, shaker-driven vibration tests, and airborne vibration tests. It can also be

used

for tests of the rms response of meters, ob-

servation of resonances in systems, electrical averaging of

resonant responses, comparisons of effective bandwidths, and

for

other tests when a signal

with

a high peak-to-rms factor

is

useful, 1381

for sary. A pair for errors

theory.

Generator, produces three different spectra audio-frequency range,

It

as

in overload testing. The low-frequency range

Random-Noise Generator

measurements when a flat spectrum down

of

these generators

demonstrations

of

random sampling,

A companion instrument, the Type

is

designed

of

various

including white noise and

for

floating, balanced or single-sided output.

makes

can

be

degrees

and

other concepts

it

particularly suitable

used

of

correlationi possible

1382 Random-Noise

INTRODUCTION 1

to

2 Hz

is

as

signal sources

of

statistical

of

noise in the

pink

of

the

neces--

noise.

1.2 DESCRIPTION. The

1381

Random-Noise Generator consists conductor power supply.

1.3 CONTROLS

noise

source,

AND

The controls and

with

all-semiconductor amplifiers and

CONNECTORS.

connectors

on

the

front

of a semi-

and rear panels

of

the

1381

Random-Noise Generator

in

Tables

1-1

and 1-2 respectively.

Two jack-top binding posts,

are

provided on the

3/4

inch below the LOW post,

instrument and offers a connection for the ground wire

power cord.

is

in

parallel wtth the OUTPUT binding

panel.

The

front

BNC

panel.

is

connector

are

listed and described

used

as

OUTPUT terminals,

A third binding post, located.

connected

at

the

to

rear of

posts

the

case

the

instrument

on

the

of of

front

the the

FIGURE

REF.

2

3

4

5

6

1-1

POWER

BANDWIDTH

CLIPPING

OUTPUT

LEVEL

OUTPUT 60QQ

(HIGH-LOW)

TABLE

Controls, Connectors, and Indicators on the

NAME

TYPE

2-position toggle

1-1

POSITIONS

OFF, POWER

switch 3-position rotary

selector switch

&-position rotary

selector switch

2

kHz, 5 kHz,

50 kHz frequency

2a, 3a, 4a,

5a,

oo

Continuous rotary

control

Three Type 938

in~line,

jack~top

binding posts spaced

% inch

apart

Pilot lamp behind GR

monogram

front

panel.

FUNCTION

Energizes

Selects

instrument.

upper

of

spectrum.

Selects

level at which

noise

is

clipped. (No

clipping

Varies

Connection

output. LOW post

connected

ground by 10 ohms but to

output

can

chassis

in=

to

be

shocted

ground by

captive link.

Indicates when instru-

ment

is

energized.

cutoff

noise

position.)

voltage.

generator

is

chassis

Controls and connectors on the rear panel.

FIGURE 1-2

REF.

2

3

NAME

OUTPUT

0.1

FUSE,

A

BNC jack

Extraction~post

fuse

holder

Screwdriver~

operated slide

switch

4

3--terminal

male

2 TYPE 1381 RANDOM-NOISE GENERATOR

TABLE

TYPE

connector

1-2

POSITIONS

100-125, 200-250

FUNCTION

Connection generator

in parallel panel

OUTPUT

terminals.

Holds 0.1-A (Sio-Bio).

Selects

proper

of

line voltage.

Line-power

connection.

to

output;

with

front-

fuse

range

input

TABLE

1·3

Accessories Supplied.

(Refer

also

to Parts List.)

5

Rear

panel

of

the

Figure

Generator,

showing

1.4 ACCESSORIES SUPPLIED.

The

accessories supplied with

Table 1-3.

1-2.

3 4

2

controls

the

and

Generator are listed

connectors.

ITEM

Power Cable, Spare

1.5 ACCESSORIES A Rack Adaptor

7-foot, 3-wire

Fuse

(0.1

A, Slo-Bio)

AVAILABLE.

Set

(P/N 0480-9722)

convert the portable bench model

standard 19-inch relay rack (refer

in

available

are

various patch cords (refer

making connections to the OUTPUT terminals.

GR

PART NO.

4200-9622 5330-0400

is

available

for

mounting in

to

paragraph 2.3). Also

to

Table

an

1-41

to

E!A

for

INTRODUCTION 3

TABLE

Available patch cords and adaptors for

1-4

output

connections.

The front-panel OUTPUT binding posts accept banana plugs, standard telephone tips, alligator The rear-panel

is

cords use

with most commercial

dips,

OUTPUT jack

available,

crocodile clips,

as

well

as a full

and

spade

terminals, and all wire

is

a female BNC connector. A wide variety

line

of

military

adaptors

coaxial connectors.

to

convert the OUTPUT terminals

sizes

up

to

number 11.

of

GR

patch

for

TYPE

NO.

274-NQ

274~NQM

274-NQS

274-NP

274-NPM

274-NPS

274-NL 274-NLM 274-NLS

274-LLB

274-LLR

274-LMB

274-LMR

274-LSB

274-LSA

1560-P95

NOTE: GR874 connectors ore 50 D and are

ically

sexless;

i.e.,

be

plugged

Double-plug

Double-plug Double-plug

Double-plug Double--plug Double-plug

Shielded Shielded Shielded

Single--plug Single--plug Single--plug Single--plug Single--plug Single-plug

Adaptor

double-plug double--plug double-plug

cable,

together.

patch

patch patch

patch patch patch

patch patch patch patch patch patch

any two, although identlco!, con

DESCRIPTION

cord,

in-line

in-line in-line

right-angle right-angle right-angle

cord, cord, cord,

black,

36"

red,

36"

black,

24"

red,

24"

black,

12"

red,

12"

to

cord,

cord, cord,

long

telephone

cord, cord,

cord, cord, cord,

patch patch patch

cord, cord, cord, cord, cord, cord,

double-plug

36" 24" 12"

long

36"

24" 12"

cord, cord, cord,

long long long

mec:han•

long

long long

36" 24" 12''

plug,

long long long

36"

long

CATALOG

0274-9860 0274-9896 0274-9861

0274-9880 0274-9892 0274-9852

0274-9883 0274-9882 0274-9862

0274-9468 0274-9492 0274-9847 0274-9848 0274-9849 0274-9850

1560-9695

NO.

4

TYPE

874-R34

874-R33

274-QBJ

776-A

1381 RANDOM-NOISE GENERATOR

Coaxial

Adaptor,

Patch

patch

cord,

shielded

GR874

BNC

double

two

double

to

BNC

plugs

double

BNC

plug

to

plug

to

GR874,

to

GR874,

BNC

36"

long

0874-9692

0874-9690

0274-9884

0776-9701

0776-9702

0776-9703

2.1

DIMENSIONS.

Section 2 -Installation

The dimensions

;--------jQl

f---·---·--8

of

the

1381

are

RACK_,O"'Nlo_Y

••

---·--___,

shown

___

in

Figure 2-1.

-1

3

FI

Dimensions

Figure

of

HANDLES

RACK

MOUNT

2·1.

the

Generator.

ON

ONLY

01

MENS!ONS

IN

INCHES

INSTALLATION

5

General 1381 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual