Simrad RA771UA Instruction Manual

SIMRAD

MARINE

RADAR

RA771UA

INSTRUCTION

MANUAL

PIN

855-106335

INSTRUCTION

MANUAL

FOR

MAFUNE

RADAR

TYPE

RA771

UA

ANRITSU

CORPORATION

MAY.

‘92

WARNING

HIGH VOLTAGE

High voltage ranging from 300V to

lOkV

are used

in

this

equipment.

Do

not touch

the

inside of the equipment during

inspection, repair,

or

maintenance until you

are

certain that

the

power switch

on

the

display unit and main power switchboard

are

turned off. Even

after

these

switches are turned off, there

may

be

high

static

voltage

at

condensers,

etc.

Always ground

high

-

voltage points using an insulated conductor.

DURING MAINTENANCE

OF

THE SCANNER UNIT

THE ANTENNA MUST NOT BE ROTATED

Never

start

maintenance work on the scanner unit until

you are sure that the main

power

switch

on the switchboard and

the power switch on the display unit

are

turned off, and the

antenna motor

-

line

in

the scanner unit

is

disconnected

of

from

connector

52

on the.MOD

PC

board. Accidental rotation of the

antenna

is

a potential hazard

to

personnel.

A

suitable,

conspicuous sign such as

"

MAINTENANCE

IN

PROGRESS

"

should be

posted on

the

display unit during maintenance

work.

CONTENTS

1.

2.

3.

4.

5.

GENERAL

1.1

Introduction

1.2 Features

OPERATION

2.1 Key Layout

2.2

Basic

Operation

2.3 Sea

Clutter

Suppression (STC)

2.3.1 Manual Sea

Clutter

Suppression

2.3.2 Automatic Sea Clutter Suppression

2.4 Rain and Snow Clutter Suppression

(FTC)

2.5 Measuring

Target

Bearings

(EBL)

2.6 Measuring Target Rages

2.6.1 Rough

Range

Estimation (Range Rings)

2.6.2

To

Measure Accurate

Ranges

(VRM)

Observation

2.7 Stretching Echoes

from

Target

for

Easy

Target

2.8 Plotting locus of Echoes

from

Moving

Targets

2.9 Setting Guard Zone around

Your

Ship

2.10 Off

-

Centering

2.11

Rejecting Interference

from

Other Radars

2.11.1

What

is

Radar

Interference?

2.11.2 Rejecting

Radar

Interference

(IR)

2.12 Erasing Heading Marker

2.13 Switching the Display Modes

2.14 The second

EBL

and

VRM

2.15 The floating function of

the

second EBL and

VRM

2.16 Setup Modes

2.16.1 Entering Setup Mode

2.16.2 Return

to

the

Radar

Mode

2.16.3 Description

of

Each Setup Mode

2.17 Navigation Data Display

2.18 Caution

INTERPRETING

RADAR

PICTURES

3.1 Propagation Characteristics of Radar Radio Waves

3.2 Echo Strength and Incident

Angle

of

Target

3.3 Shadow Zones

3.4

False

Echoes

MAINTENANCE

4.1

Preventive maintenance

4.2 Checking Fuses and Voltages

INSTALLATION AND ADJUSTMENT

5.1

5.2

5.3

5.4

5.5

5.6

8.7

5.8

Unpacking Instructions

Installation Materials

Power Requirements

5.3.1 Power Supply Voltages

5.3.2 Power Systems

Proper Location for Installation of Radar

5.4.1 Scanner Unit
Installing Scanner

Unit

Installing Display

Unit

5.6.1 Cable Connection

5.6.2 Display unit grounding

5.6.3 Adjustments

Laying Cables

Installing the External Buzzer

5.9 Interface

5.9.1

Compass

Interface

5.9.2

NMEA

Interface

Interference

(EMI)

5.10.1

On

Radar

Installation

5.10.2

Radio

Equipment and Using Frequency

5.10.3 Improvement Procedure

for

EMI

5.10 Countermeasurement

for

Electromagnetic

6.

SPECIFICATIONS

6.1 Principal Specification

6.1.1

Overall

Characteristics

6.1.2

Scanner Unit

6.1.3

Display

Unit

6.1.4 Interface Signals

6.1.5

Allowable

Safe Distance

from

Magnetic

Compass

6.2

Standard Equipment

6.3 Option

6.4

Dip

switch selection

ATTACHED DRAWINGS

~~

General System Diagram
Scanner Unit External

View

Display Unit External

View

Outline Drawing Rectifier Unit

Rectifier

Unit External

View

Inter

Connection Diagram

Scanner Unit Circuit

Diagram

Display Unit Circuit

Diagram

Rectifier Unit Circuit Diagram

Rectifier

Unit Circuit Diagram

24W138742
23W61747

~ ~~

23W61200
23W56729

24W138743
24W138587
23W61043
24W130456
24W138330

1.

GENERAL

1.1

Introduction

The

RA771UA

Marine Radar

is

a

marine navigational

pulse radar with

4kW

peak power output for

small

and

medium

-

sized vessels. The Display Unit uses

a

10-inch

CRT

to display monochrome picture images

at

four different

brightness levels.

recently developed by Anritsu Corporation.

It

is

one of a series of digital marine-radars

1.2

Features

Many versatile advanced technologies, such

as

a

microcomputer, an LSI exclusively designed for video

signal processing, high

-

integrated

LSIs,

have been

incorporated

in

the radar circuitry.

intensities of signals reflected from targets can be
displayed

at

four different brightness levels.

In addition, various automatic functions, video image

expansion, off

-

centering, plotting, electronic cursor, and

offset

are

provided.

a.

High Resolution and Sharp Picture

ranges. This unique outstanding feature has been achieved

by using a

"

clean picture

"

circuit, that

is

a

high

resolution circuit developed by Anritsu.
b. Automatic Sea Clutter Suppression and Auto Gain

Control

(AUTO)

In addition to having conventional sea clutter

suppression, this radar has a newly

-

developed automatic

sea clutter suppressor.
has an automatic gain control

for

easy operation.

As

a result, radar video images can be stored and the

Picture resolution

is

excellent

at

short and medium

And not only a sea

clutter

suppressor, this new radar

c.

Automatic Tuning

eliminates

the possibility of miss

-

tuning

or

function

lowering of gain.

d. Off

-

Centering

centered from the screen center. The off

-

centered position

can

be

set

to either position of

60%

forward or

60%

backward.

size.

e.

Electronic Cursors

:

Markers

(VRMs)

(i)

This radar can display two

EBLs

and two

VRMs.

The

VRM

range can be displayed by nautical

miles

(NM),

kilometers

(KM)

or statute

miles

(SM)

.

(ii)

The center

of

EBL2

and

VRMZ

can be relocated

from

the
picture center (own ship point) to any point on the
picture. This offset facility for

EBL2

and

VRM2

results in

To maintain optimum gain

at

all

times,

auto-tuning

Your ship's position

in

the picture can be off-

This results

in

the

effective use of the display

Electronic Bearing Lines

(EBLs)

and Variable Range

easy measurement

of

the bearing and range

of

any

two

selected

points.

f.

Guard Zone

EBL1.

The sector angle varies

in

about

6

degree

increments.

An

external buzzer can be easily installed

in

addition

to

built-in

alarm

buzzer.

g.

Plotting picture

screen.

The tracking

time

can

be selected

from

:

15

sec.,

30

sec.,

1

min.,

3

min.,

6

min.,

and continuous.

An

alarm

zone sector can be

set

by using

VRMl

and

The track

of

target picture can be displayed on the

2.

OPERATION

2.1

Key

Layout

The key and control knob layout

is

shown below.

POWER SWITCH

OPERATE KEY

RANGE

UP

KEY

*GUARD ZONE KE

RANGE

DOWN

KEY

RANGE RING

AUTO

KEY

BRILLIANCE KEY

*VRM

KEY

*EBL' KEY

CONTROL KNOB

MOTOR

FUSE

Fig.

2-1

Range

(NM)

Pulse Width(+s) /Repetition

(Hz)

I

fi

12,24,48

0.8

/

600

0.5

to

1.5

0.125,O

.25

0.08 / 1800

0.25

/

1200

*(ST

ON:

0.8

/

600)

0.08

/

1800

*(ST

ON:

0.25

/

1200)

3,6

<

Gain Adjustment

>

Press the GAIN key to set the
gain adjustment mode. The underline
shown below will be displayed

on

the

screen.

Indicates that the gain
adjustment mode is selected.

Turn the control knob to adjust the
gain. The gain adjustable range is
from

0

to

50.

Turning the control knob clockwise
elevates the level, enhances
reception sensitivity and makes
targets visible. Turning the
control further clockwise changes
the brightness level of echo

signals reflected from targets with

high reflection coefficients.

For

long-range observations, increase

the gain by turning the control knob

clockwise

so

that slight receiver
noise can be observed. (Receiver
noise usually appears on the entire

surface

of

the display as speckled

noise.

)

Conversely, excessive gain at short
range

will

obscure the picture with
noise and unwanted echoes. Small
targets will be concealed in the
obscure areas.

In such a case, turn the control
knob counterclockwise to the
appropriate point. The intensities
of signals reflected from targets
are expressed as changes

of

brightness.

Adjustment

>

Press the key to change the CRT

<

Picture Brilliance

brightness and the panel

illumination. One press varies the

brilliance by one level.

U

2-3

<

Operate Keys and

Controls

Depending

on Circumstances

>

Refer

to

paragraph

3.2

and

after.

<

To

suspend

radar

operation

>

Press

the

OPERATE

key

once.

The

radar

will

stop transmission and

the radar picture

will

disappear.

To

resume

radar operation,

press

the

OPERATE

key

once

more.

<

To

Stop

Radar

Operation

>

Press

the POWER SWITCH more than

3

seconds.

2.3

Sea

Clutter Suppression

(STC)

2.3.1 Manual Sea Clutter Suppression

(

STC:

Sensitivity

Time

Control)

(i)

Press

the STC key. The underlined numerical

indication shown below

will

be displayed and the sea

clutter suppression mode

(STC)

will

be

set.

F

0

G30

Indicates

STC

adjustment mode

is

selected.

(ii)

Turn the control knob to adjust the level. The

STC

adjustable range

is

from 0 to

50.

even when the sea

is

calm. When the sea

is

rough, intense

echoes appear over a wide area and sometimes make targets

invisible.
The STC control decreases such

sea

clutter

and makes

targets easily visible.

Turn

the control knob clockwise to

decrease sea clutter.

If

the control knob

is

turned too

far,

echo signal from important targets may disappear.
Adjust the control very cautiously by observing the
picture with utmost care.

Usually the STC control should be

set

so

that there

is

no sea clutter at

or

near the display center when the

sea

is

calm, with the distance range preset to

a

minimum

or

0.125

NM.

short-distance sensitivity (gain) lower and the long

-

distance sensitivity (gain) higher.

For

this reason, no

picture may emerge on the display

if

the sea

is

calm and

there

are

no

large targets

near

your ship when the range

is

set

to

0.125

to

0.5NM

and

the

level

is

more than

30.

2.3.2 Automatic Sea Clutter Suppression

(1)

Automatic Sea Clutter Suppression and Automatic Gain

Sea clutter

is

observed from short-range sea surfaces

The STC

circuit

is

designed primarily to make the

Control

APPENDIX

(RA770UA

MARINE

RADAR

INSTRUCTION

MANUAL(P2-4)

)

Press the

AUTO

key. The indication shown below

will

be displayed and the auto sea-clutter suppression

mode

will

be

set.

At

the

same

time, the auto gain control mode

will

be

set.

Every pressing of the

AUTO

key, the function

and display

will

change

"

AT

1" and

"

AT

2

"

alternately.

The

GAIN

and/or the FTC

can

be

used with manual control

together with the

AUTO

mode.

Press

the STC key to return the manual control mode.

AT

1

Indicates the auto

STC

and

auto gain mode

is

selected.

The functions

of

AUTO

are

as

follows;

AT

1 : Use

this mode to watch the coast-line

in

the

channel,

or

to

watch the sea with many

small

islands

around your ship. Also use this mode in the harbor.
in the manual mode.

This mode

is

similar

to the "low

STC

and low

GAIN

"

state

AT

2

:

Use

this mode to suppress the

sea

clutter in the

open sea. This mode

is

similar to the "high STC(depends

on sea

state)

and high

GAIN

"

state in the manual mode.

note: To suppress the long

-

range rain/snow clutter, use

the manual FTC and/or

GAIN

control with

AUTO

mode.

Presetting the

ATl/AT2

level

"

AT

1

"

and

"

AT

2''

level can be

set

by using following

procedures.

1.

Set the

AUTO

mode to

"

AT

1

"

or

"

AT

2"

to change the

level.

To change the

"

AT

1

"

level,

set

the range scale more than

0.75

NM.

2.

Press

and hold the

"

BRILLIANCE

"

key

to

enter

the SETUP

MENU.

3.

Press and hold the

AUTO

key, and press the

"

RANGE-UP

"

key during the buzzer

is

sounding. The setting levels

are

displayed on the

screen

as

follows;

ATI

LEVEL(N0RM

7)

7

AT

2

LEVEL(N0RM

5)

5

4.

When change the

"

AT

l",

turn the encoder knob to change

the level. The

"

AT

1"

level changes the

AUTO-GAIN

preset

level (not

to

change the

AUTO-STC

level).

5.

When change the

"

AT

2",

press the

"

RANGE-DOWN

"

key

to

display the underline to

"

AT

2".

Then turn the encoder

knob to change the

AUTO-STC level (not to change the

AUTO

-

GAIN

level).

6.

Press

the TRANSMITT key to return the normal display.

2-5

Press

the

AUTO

key. The indication shown

below

will

be

displayed and the auto

sea-clutter

suppression

mode

will

be

set.

At

the

same

time,

the auto gain control

mode

will

be

set.

to

"

AT

2"

and the auto sea-clutter suppression

will

enhance the effect.

Press the

AUTO

key again. The indication

will

change

AT

1

Indicates the auto STC and

auto gain mode

is

selected.

(2)

Automatic Sea Clutter Suppression and Manual Gain

Control
Press

the

GAIN

key

to

return

to

manual

gain

control

mode. The indication shown below

will

be

displayed and the

auto sea

-

clutter suppression mode

will

remain.

Indicates the auto STC and

manual gain control mode

is

selected.

(3)

Automatic Sea Clutter Suppression, Manual Gain

Control and

FTC

Control

Press

the FTC key to add the FTC control mode. The

indication shown below

will

be displayed and the auto

sea-

clutter

suppression

mode

will

remain.

AT

1

G

30

Indicates the auto STC,

manual gain

and

FTC control

mode

is

selected.

(4)

Manual control

mode. The indication shown below

will

be displayed.

Press

the STC key

to

return

to

the manual control

Indicates the STC adjustment

mode

is

selected.

2-6

2.4

Rain

and

SnoxClutter Suppression (FTC)

(i)

Press

the FTC key. The indication shown below

will

be

displayed and the rain and snowclutter suppression

mode

(FTC)

will

be

set.

Indicates the FTC mode

is

selected.

(ii)

Turn the control knob

to

adjust the level range from

0

to

50.

Clutter from rain, snow

or

fog

may appear on a radar

In

such

a

case,

turn the control knob at the FTC mode

picture and sometimes

mask

targets completely invisible.

clockwise. Then the contours

of

concealed targets

will

appear. Since the radar uses

a

LOG

amplifier, the FTC

function

is

very effective. But

it

tends to weaken the

intensities

of

echoes from short-range targets. Adjust

STC

and gain for the best picture.

counterclockwise to level

0

when there

is

no rain

or

snow.

In this state the FTC function

is

ineffective.

Always turn the control knob at the

FTC

mode

fully

2.5

Measuring

Target

Bearings

(EBL)

Press

the

EBL

key to

select

the electronic cursor and

the indication

below

will

be displayed on the bottom of

the screen. Turn the control knob to move the

EBL

to
coincide with the target to measure the bearing from your
ship's heading.

Press

the

EBL

key once again to erase

the

EBL.

(To erase the

EBL,

the

EBL

function must be selected

at the moment.

)

EBL

0.0'

2.6

Measuring Target Ranges

2.6.1

Rough Range Estimation (Range Rings)

Press the range ring key. Fixed range marker rings

will

be displayed

as

shown below. The interval of range

marker rings depends on the range as tabulated below:

1.5

0.25

Press

the range ring key once

more

to

erase

the range

marker rings.

2.6.2

To

Measure Accurate

Ranges

(VRM)

ring

and the indication below

will

be displayed on the

bottom of the screen.

Turn

the control knob to move the

VRM

to

coincide with

the

target

to

measure

the

accurate

range

from your ship. Press the

VRM

key once

again

to

erase

the

VRM.

(To

erase

the

VRM,

the

VRM

function

must

be

selected

at the

moment.)

Press the

VRM

key to

select

the variable range marker

VRM

O.ONM

2.7

2.8

2.9

Stretching Echoes

from

Target

for

Easy Target

Observation

the indication "ST"

is

displayed on the upper-right

position

of

the screen.

from medium

or

longrange targets

are

too

small

for

observation.

Press

the ST key once more to

release

the

function.

Press

the ST key. The stretching function

is

set

and

This

stretching function

is

mainly used when echoes

Plotting Echo Track

from

Moving Targets

indication below

will

be displayed on the top-right of the

screen.

Press

the

TRACK

key to plot

echoes

(picture) and the

TRACK

ISSEC

The

track

of target picture

is

displayed

on

the

screen. The tracking

time

can be selected from

:

15

sec.,

30

sec.,

1

min.,

3

min.,

6

min., and continuous.

To erase

the

track of target picture, press the

TRACK

key more than 3 seconds.

Setting Guard Zone around

Your

Ship

possible collision with

other

ships, for surveillance, and

warn against running ashore.

The

guard zone function

is

used to warn against

(i)

Press

the

VRM

key and turn the control knob

to

set

the range of guard zone.

(ii)

Press the

EBL

key and turn the control knob to

set

the

EBL

direction

of

the guard zone.

L

-

8