KING KMA 20, KR 21 Installation Manual

KIN

G

KMA

20/KR

21

MARKER

BEACONRECEIVER

ISOLATIONAMPLIFIER

INSTALLATION

MANUAL

006-0044-02

REV.

2

JUNE,

1976

KlNG

KMA

20

/KR

21

MARKER

BEACON RECEIVER/

ISOLATION

AMPLIFIER

TABLE

OF

CONTENTS

SECTIONIGENERALINFORMATION

Paragraph

Page

1. 1

Introduction

1-1

1.

2

Technical Characteristics

1-2

1. 3

Accessories Required

1-6

SECTIONIIINSTALLATION

2.

1

General

2-1

2.2

Unpacking and

Inspecting Equipment

2-1

2.

3

Installation

Notes and

Precautions

2-1

2.4 Installation

Procedure

2-2

2.

5

Marker

Antenna

Installation

2-2

2.

6 KA 40

Installation

(Optional)

2-3

SECTION

III

OPERATION

3.

1 Marker

Beacon

(KMA 20 and KR

21)

3-1

3.2

Isolation Amplifier (KMA

20)

3-2

LIST

OF

ILLUSTRATIONS

Figure Page

2-1

KMA 20 Installation

Drawing

2-4

2-2

KR

21

Instanation

Drawing

2-5

2-3

KA

40

Instanation

Drawing

2-6

2-4

KMA

20

Interconnect Diagram

2-7

2-5

KR

21 Interconnect Diagram (27. BV

DC')

2-9

2-6

KR 21 lnterconnect

Diagram (13. 75VD(')

2-9

2-7

KA

40

lnterconnect Diagram

2-10

2-8

Pin Function

for

000-1024-00

thru

-16

2-11

i

KING

KMA 20/KR

21

MARKER

BEACON

RECEIVER/

ISOIATION

AMPLIFIER

HISTORY

OF

REVISIONS

Hevision

1, August 1972

Page

Reason

for

Change

Title

Page

Denotes

New

Revision

Warranty

New

Warranty

Contents

Table

of

Contents

Added

History of Rev.

History

Revision

Added

1-1

Lamp

Test

Information

Added

1-3

Sensitivity

and

Selectivity

Revised

1-4

Word Misspelled

1-6

Installation

Parts List

Added

2-1

Warning

Note Added

2

-2

Paragraph

6 Changed

to

7.

New

Paragraph

6 added.

2-3

Figure

Numbers corrected

2-4

New

Installation

Drawing

2

-5

New

Installation

Drawing

2-6

Drawing

Turned on

Page

2-7

Interconnect Corrected

2-11

Pins

Reversed

2

-13

Figure Added

2-15

Figure Added

3

-1

Marker Dese ription

Changed

3-1

Information Added about

HI-LO

Switch

3-2

09/11

Information

Added

ii

KMA20/KR 21

MARKER

BEACON

RECEIVER/

ISOLATION

AMPLIFIER

HISTORY

OFREVISIONS

Revision 2, June,

1976

Page

Reasons for Change

Title Page

Denotes

New Revision

Warranty

Deleted

Contents

Page Number

changes

History

of Revision Added for

Revision 2

1-3

Technical

Characteristics Updated

2-2

Paragraph

2.3

(5)

updated

Paragraph

2.3

(7)

updated

2-7

Interconnect updated

2-9

Figure

2-6A

changed to

2-5

Figure

2-6B

changed to

2-6

2-11

Figure

2-8

updated

3-2

Section

3.2 updated

iii

KING

KMA

20/KR

21

MARKER BEACON

RECEIVER/

ISOLATION AMPLIFIER

SECTION

I

GENERAL

INFORMATION

1.1

INTRODUCTION

The

King

KMA 20 is a

compact

transistorized unit

providing the

functions

of

marker

beacon

receiver,

isolation amplifier

and

audio control panel.

The

unit has been

styled

to harmonize with

the

all new

generation

of

Silver

Crown

panel mounted

equipment.

TSO

certification

of the

KMA 20 assures

operation under

varying

environmental

conditions.

The KMA

20 is

designed to

provide

a

uniformly functioning

aircraft radio

system when

utilized

with other

units

of

the new Silver

Crown

line. Although the

equipment is designed

primarily

for use with the KX

170

NAV/COMM unit,

it will also perform

effeciently

with

older Silver

Crown

transceivers and

radios.

Significant

new

features

of

the KMA 20

design

include its

AUTO

switch

feature:

semi-

concealed

marker light

presentation and

its ability

to control COMM and

NAV audio

independently. Automatic

dimming

circuitry

for the marker

lamps,

to

compensate

for

ambient

cockpit

lighting,

is also

incorporated in the design.

Within the KMA 20, the

marker beacon receiver comprises

one

section

of

the

unit.

The

marker

receiver

of

the KMA 20,

available

without

the isolation

amplifier and audio

panel is the KR 21. The

receiver

is

a crystal controlled

superheterodyne

receiver

and

has

excellent

selectivity

and

freedom

from

interference

of

television and FM stations.

Operating controls

for the

marker receiver consists

of

two

toggle switches on the KMA

20: a

HI-LO

sensitivity

and lamp

test control and an

audio

selector

switch. The KR

21

has

only

the

HI-LO

sensitivity

and

lamp

test control. A three light

presentation

is de

signed into the

front

panel of

the unit

with

colored lenses

to indicate passage over

the

markers.

Besides

the

colors,

the stations

are identified

by

the

letters

A-O-M

engraved

on the lenses plus

the

appropriate

frequency

audio

tone.

Should the

aircraft

user

desire

a

remote

location for

the

marker

lights,

King

Radio Corporation

manufacturers

an

optional

remote

light

assembly

designated the KA 40

for

use with the KMA

20

only.

The

isolation

amplifier

of

the KMA 20

makes

possible the

combining

of

all receiver

audio

inputs

into

a single cockpit

speaker

with 40db

of

isolation between each

radio. The

input

power levels

of

the

signals are

amplified

to the

level

necessary

to drive a

4 ohm

speaker.

An

electronic

muting

circuit (diode

switch) is provided to

automatically

isolate

the output

of

all receivers from

the isolation amplifier

whenever the microphone

button

Rev.

1,

August, 1972 Page

1-1

KING

KMA 20/KR 21

MARKER BEACON

RECËIVER/

ISOLATION

AMPLIFIER

is

pressed.

This

feature

eliminates

the

possiblity of

audio feedback in the cockpit.

The

amplifier design utilizes

only

one

integrated

circuit

and a

push-pull

output

stage

for

high

reliability.

Audio

control

functions

of the

Silver

Crown

radio

system are

performed at

the

front

panel of the KMA 20. A microphone

selector

rotary

switch,

a

series

of

eight audio

selector switches and a marker beacon

receiver

sensitivity

control are the operating

controls

of

the

unit.

The microphone selector routes audio

and

keying information to

the

selected transceiver or to

a EXT

ramp

hail

speaker or passenger

address system.

The

AUTO switch control

of the

standard

model is

utilized

in

conjunction with the

micro-

phone

selector

switch.

For normal operation

of

the AUTO

switch,

COMM 1 and COMM

2

are placed in

the

center

(off) position. With

the

AUTO

switch in

the

SPEAKER position,

the

receiver

audio selected

is

automatically

controlled

by the operation of

the

micro-

phone

selector.

Thus if

transmitting

on

COMM 1,

receiver

audio

for

COMM

1

will be

routed to the

cockpit

speaker.

This

feature eliminates the constant manipulation

of

COMM receiver

audio

selectors

when

switching

back and

forth

between

transmitters.

Speaker,

off

or

mute,

and

headphone audio

control

of

each of

the

aircraft

radios is

accomplished

with the

remaining

three-position

toggle

switches.

A

series type solid state

regulator

is used to

supply

the regulated

voltage

to

the

marker

receiver and

audio boards

of

the

unit. Since

each aircraft

installation is

wired

for

eithier

13.

75

or

27. 5V operation

of the

unit,

the KMA 20

and

KR 21 are

completely

interchange-

able

between

aircraft with

no

internal

wiring

changes.

1.2 TECHNICALCHARACTERISTICS

MARKER

BEACON

RECEIVER

-

KMA

20/KR

21

SPECIFICATION

CHARACTERISTIC

TSO

COMPLIANCE: TSO C35c Env.

KING KMA 20, KR 21 Installation Manual

Specifications and Main Features

Frequently Asked Questions

User Manual