Clear-Com KB-111A Instruction And Service Manual

KB-111A

Speaker Station

INSTRUCTION

and

SERVICE MANUAL

III~I~

Clear-Co.

~I'

Intercom Systems

945 Camelia St. Berkeley, California 94710 510-527-6666

Clear-Com 810026 8/15/88

REV.

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DOCUMENTATION

ADDENDUM

KB-ll1A

MANUAL

• . f

REV. A

.•

.j

..

..

November

17,

1987

I .1

r •

MIC

TO

LINE

GAIN

LEVEL

INCREASE

In

effecting

a

4dB

Mic

to

Line

Increase

In

gaIn

level,

the

following

changes

have

been

made:

Change:

270K

OHM

R18, 36 390K

OHM

27pf

C9

lSpf

180pf

CI0

100pf

CLEAR-COM

KB-IIIA

SPEAKER

STATION

INSTRUCTION & SERVICE

MANUAL

TABLE

OF

CONTENTS

Section

Page

II

I

Introduction

to

the

KB-IIIA

•.•....•..••...•.•

1

II

Headsets

and

Mics

•..•...•.........••..•••.•••

l

III

Installation

.•.....••.•••••.•••••••..••••••••

3

IV

Operating

Controls.·

•••..••.•.••.••..•••••••.

7

V

Parts

Listing

••..•.•..•.•••••.•.•.....•••••.•

8

VI

Specifications

•...•.•.........••••.•.••.•••••

8

VII

Call

Signalling

Modification.·

••••••....•••••

9

Illustrations

:

Headset

Y-Cable

.•.•.•••••••.••.•.•.••••

2

Figure

1

Figure

2:

Headset

Extension

Cord.··

•••••.•.••••••

2

Figure

3:

KB-IIIA

Mounting

Dimensions

••..•••.••••

4

Figure

4:

KB-IIIA

Block

Diagram

•.••.••••••••.••••

4

Figure

5:

Two-Channel

Interconnect

Wiring

•.••••••

5

Figure

6:

Portable

Unit

Connections

•.•.•••.••••••

6

Figure

7:

Alternative

Signalling

•..•••.••••••••••

9

Figure

8:

KB-IIIA

Schematic

••••.•••••••••••••••.

10

NOTICE:

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Clttar-CDIII

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"very

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CD

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III

thlt

In/ormation

contained

In

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product ••nua/a. chit

inlor.atlon

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.ubJllct

CD

change

Nithout

notice:"

•

I.

INTRODUCTION

TO

THE

KB-IIIA

REMOTE

STATION

The

Clear-Com

KB-lllA

is a Remote

Speaker

Station

that

provides

talk/

listen

communications

on

one

of

two

channels

within

our

closed-circuit

intercom

system.

It

features

a

wide

frequency

response,

high

out-

put

speaker

and

the

ability

to

operate

with a carbon

headset

OR

a

dynamic

headset,

handset,

or

push-

to-talk

mic.

The

KB-IllA

features

the

Clear-Com

contoured

frequency

response

for

consistently

excellent

speech

in-

telligibility

in

all

surroundings.

The

speaker

delivers

crisp

sound

pressure

levels,

clearly

audible

in

high-

or

low-noise

environments.

The

Remote

Station

features

Automa-

tic

Headset

Detection;

its

built-in

mic

preamp

automatically

shuts

off

when

the

headset

is

disconnected,

eliminating

noise

pick-up

on

the

intercom

line.

The

intercom

cir-

cuitry

incorporates

a

mic

limiter,

which

assures

constant

talk

levels

~nd

prevents

overload.

The

KB-lllA's

speaker

can

remain

on

at

all

times,

or

you

can

turn

it

off

so

that

private

conversations

may

be

carried

out

with a headset

or

telephone

handset . The

three-

position

mic

switch

allows

you

to:

1)

keep

the

mic

on

at

all

times;

2)

activate

the

mic

momentarily;

3)

switch

off

the

mic

so

the

KB-

lIlA

can

function

as a "listen-

only"

station.

II.

HEADSETS

AND

MICS

To

provide

you

with

the

ability

to

talk

on

the

intercom

channel,

the

KB-lllA

contains:

--one

1/4"

phone

jack

for a stan-

dard

carbon

headset,

AND

--one

4-pin,

male,

XLR-type

connec-

tor

(D4M)

for a dynamic

headset,

telephone-style

handset,

or

push-

to-talk

mic

The

KB-lllA

provides

an

adjustable

sidetone

circuit

which

allows

you

to

vary

the

level

of

your

voice

as

you

hear

it

in

your

headset

or

speaker.

The

circuit

also

prevents

feedback

when

using

the

speaker

and

a

mic

simultaneously.

You

need

only

adjust

the

sidetone

once,

even

if

other

Stations

subsequently

join

or

leave

the

intercom

system.

Designed

for

custom-mounting,

the

KB-lllA

is

built

on

a

charcoal-

brown,

aluminum

panel,

5/32"

thick,

that

can

be

installed

in a cut-out

in

any

convenient

surface,

or

moun-

ted

inside

a

6" x 8"

Nema

electri-

cal

enclosure.

The

Station

connects

to

the

intercom

system

via

a

5-

pin

terminal

block

behind

the

front

panel.

Clear-Com

offers

the

"P"

Box,

which

allows

you

to

convert

the

KB-lllA

to a portable

Remote

Station.

The

P-Box

is-a

sturdy,

sloped-front,

steel

enclosure

with

solid

walnut

sides.

When

installed

in a P-Box,

the

KB-lllA

connects

to

the

inter-

com

system

with

3-pin,

XLR

connec-

tors·

~fuen

the

KB-lllA

is

installed

in

the

P-Box,

it

provides

talk/listen

capability

on

one

channel.

Standard

two-conductor

shielded

mic

cable

interconnects

stations

within

the

intercom

system.

The

KB-lllA's

built-in

headset/

speaker

amplifier

can

drive a stan-

dard

headset

to

levels

greater

than

110

dB

SPL.

The

Station's

mic

preamp

automatically

shuts

off

when

the

headset

is

disconnected,

there-

by

eliminating

hum

pick-up.

NOTE:

If

you

use a carbon

headset

and a dynamic

headset

simultaneous-