Furuno 1622 User Manual

MARINE RADAR

MODEL 1622

C

All rights reserved.

PUB. No. OME-34520

(DAMI)

FIRST EDITION : JUN. 1999

9-52, Ashihara- cho,
Nishinomiya, Japan

Telephone: [phone]
Telefax: 0798-65-4200

Printed in Japan

Your Local Agent/Dealer

J2 : OCT. 7, 2002

MODEL1622

SAFETY INSTRUCTIONS

WARNING

ELECTRICAL SHOCK HAZARD

Do not open the equipment.

Only qualified personnel
should work inside the
equipment.

Turn off the radar power
switch before servicing the
antenna unit. Post a warn­ing sign near the switch
indicating it should not be
turned on while the antenna
unit is being serviced.

Prevent the potential risk of
being struck by the rotating
antenna and exposure to
RF radiation hazard.

Wear a safety belt and hard
hat when working on the
antenna unit.

WARNING

Use the proper fuse.

Fuse rating is shown on the equipment.
Use of a wrong fuse can result in equipment
damage.

Keep heater away from equipment.

Heat can alter equipment shape and melt
the power cord, which can cause fire or
electrical shock.

The useable temperature ranges are

Antenna unit: -25˚C to +70˚C
Display unit: -15˚C to +55˚C

CAUTION

WARNING LABEL

Serious injury or death can
result if someone falls from
the radar antenna mast.

Do not disassemble or modify the
equipment.

Fire, electrical shock or serious injury can
result.

Turn off the power immediately if water
leaks into the equipment or the equip­ment is emitting smoke or fire.

Continued use of the equipment can cause
fire or electrical shock.

The warning label shown below is
attached to the display unit. Do not remove
this label. If the label is peeling off or is
illegible, contact FURUNO for replacement.

WARNING

To avoid electrical shock, do not
remove cover. No user-serviceable
parts inside.

Name: Warning Label (1)
Type: 86-003-1011-0
Code No.: 100-236-230

i

TABLE OF CONTENTS

INTRODUCTION .......................................................................................iii

SYSTEM CONFIGURATION ..................................................................... iv

PRINCIPLE OF OPERATION.....................................................................v

1. OPERATION...........................................................................................1

1.1 Control Description............................................................................................................1

1.2 Indications and Markers ....................................................................................................2

1.3 Turn ing the Radar On/Off..................................................................................................3

1.4 Tran smitting, Sta n d -by ......................................................................................................3

1.5 LCD Tone and Brilliance....................................................................................................3

1.6 Selecting the Range..........................................................................................................3

1.7 Receiver Sensitivity...........................................................................................................4

1.8 Suppressing Sea Clutter.................................................................................................... 4

1.9 Suppressing Rain Clutter................................................................................................... 5

1.10 Range Rings ...................................................................................................................5

1.11 Cursor..............................................................................................................................5

1.12 Heading Marker ...............................................................................................................6

1.13 Menu Operation...............................................................................................................6

1.14 Control Panel Brilliance...................................................................................................7

1.15 Measuring the Range......................................................................................................7

1.16 Measuring the Bearing....................................................................................................8

1.17 Shifting the Display..........................................................................................................8

1.18 Zoom...............................................................................................................................8

1.19 Target Trails.....................................................................................................................9

1.20 Guard Alarm Zone...........................................................................................................9

1.21 Interfer e n ce Rejector.....................................................................................................10

1.22 Echo Stretch..................................................................................................................11

1.23 Watchma n.....................................................................................................................11

1.24 Navigation Data.............................................................................................................12

1.25 Displaying Navigation Data During Stand-by.................................................................12

1.26 Echoes in Black or White...............................................................................................13

1.27 Selecting Ranges to Use...............................................................................................13

2. RADAR OBSERVATION ......................................................................15

2.1 General...........................................................................................................................15

2.2 False Echoes............................................................................................................... ...16

2.3 SART (Search and Rescue Transponder) .......................................................................17

2.4 Racon (Radar Beacon)....................................................................................................19

3. MAINTENANCE, TROUBLESH OOTIING ............................................21

3.1 Maintenance....................................................................................................................21

3.2 Replacing the Fuse.........................................................................................................21

3.3 Troubleshooting...............................................................................................................22

3.4 Magnetron Replacement.................................................................................................22

3.5 Synchro Belt Replacement..............................................................................................22

SPECIFICATIONS................................................................................SP-1

INDEX..............................................................................................Index-1

Declaration of Conformity

ii

INTRODUCTION

A Word to FURUNO Model 1622
Owners

FURUNO Electric Company thanks you for
purchasing the MODEL 1622 Marine Radar. We
are confident you will discover why t he
FURUNO name has become synonymous with
quality and reliability.

For over 50 years FURUNO Electric Company
has enjoyed an enviable re put at ion for quality
and reliability throughout the world. This
dedication to excellence is furthered by our
extensive global netwo rk of agents and dealers.

Your radar is designed and constructed to meet
the rigorous demands of the marine
environment. However, no machine can perfor m
its intended functio n unless properly insta lled
and maintained. Please carefully read and
follow the installatio n, operation and
maintenance procedures set f ort h in t hi s
manual.

We would appreciate feedback from you, the
end-user, about whether we are achieving our
purposes.

Thank you for considering a nd purchasing
FURUNO.

Features

• Aut omatic control of sensit ivity and STC for

simplified operation.

• Target s can be displayed in blac k o n w hite

background or vice versa, for optim al v iew ing
under any lighting.

• On-screen alphanumeric readout of all

operational informati on.

• St andard features include D is play Shift, EBL,

Echo Stretch, Target Trail, G uard Alarm,
Interference Rejector, VRM, Zoom.

• Guard zone watches for targets entering (or

exiting) a guard zone.

• Operates on 12V or 24V power and

consumes approx. 35 watts power.

• Position in latitude and longitude, speed, and

range and bearing to a waypoint can be
shown in the bottom text area. (Requires
navigation data input in NMEA 0183 format.)

• Navigation data such as posit ion, w at e r

temperature and depth can be shown d uri ng
stand-by. (Requires appropriat e sensors.)

• LC D equipped with temperature sensor with

maintains viewab il it y under temperature
change.

• Can be connected to Radar Remote Display

FMD-1712.

Your radar has a large variety of funct ion s, all
contained in a rugged plastic case. All controls
respond immediately to t he operator’s comman d
and each time a key is pressed the
corresponding change can be se en on the
screen.

The main features of the MOD EL 16 22 are

• Daylight viewing radar spec ially designed for

small craft and sailing y acht s .

• Traditional FURUNO reliability and quality in

a compact, light-weig ht and low - cost radar.

• Compact and light-weight radome ant enna

with precision 34 cm center-fed radiator.

• St epping scanner motor.

• Hi gh definition 6-inch LCD display.

iii

SYSTEM CONFIGURATION

ANTENNA UNIT
RSB-0060

SIGNAL CABLE (Select one.)
MJ-A10SPF0003-050 (5 m)
MJ-A10SPF0003-100 (10 m)
MJ-A10SPF0003-150 (15 m)
MJ-A10SPF0003-200 (20 m)
03S9175 (30 m, option for 24 VDC only)

RECTIFIER

PR-62

DISPLAY

UNIT

RDP-125

POWER CABLE
MJ-A3SPF0013-035

NMEA 0183 Cable
MJ-A6SPF0012-050 (5 m)
MJ-A6SPF0012-100 (10 m)

SIGNAL CABLE ASSY.
MJ-A10SPF0008-XXX
(supplied with FMD-1712)

(1 m)

Options shown with
dashed lines.

EXTERNAL

BUZZER

OP03-136

NAVIGATOR
(NMEA 0183)

SOUNDER

RADAR REMOTE

DISPLAY

FMD-1712

SHIP'S MAINS

100/110/115/220/230 V AC

SHIP'S MAINS
12/24 VDC

iv

PRINCIPLE OF OPERATION

What is Radar?

The term RADAR is an acronym meaning RAdio
Detection and Ranging. It is a device which
measures the time it takes for a pulsed signal to
be reflected back from an object.

How Ships Determined
Position Before Radar

The use of echoes to determine position did not
begin with radar. Ships would sound a short
blast on their whistles, fire a shot, or strike a bell
as an aid to navigation when running in fog near
a rugged shoreline. The time between the
origination of the sound and the returning of the
echo indicated how far the ship was from the
cliffs or the shore. The direction from which the
echo was heard indicated the relative bearing of
the shore.

How Radar Determines Range

Radar determines the range to the target by
calculating the time difference between the
transmission of a radar signal and the reception
of the reflected echo. It is a known fact that
radar waves travel at a nearly constant speed of
162,000 nautical miles per second. Therefore
the time required for a transmitted signal to
travel to the target and return as an echo to the
source is a measure of the range to the target.
Note that the echo makes a complete round trip,
but only half the time of travel is needed to
determine the one-way range to the target. This
radar automatically takes this into account in
making the range calculation.

Therefore, if one knows the direction in which
the signal is sent out, one knows the direction
from which the echo must return.

Radar Wave Speed and
Antenna Rotation Speed

The speed of the radar waves out to the target
and back again as echoes is extremely fast
compared to the speed of rotation of the
antenna. By the time radar echoes have
returned to the antenna, the amount of antenna
rotation after initial transmission of the radar
pulse is extremely small.

The Radar Display

Targets are displayed on what is called a Plane
Position Indicator (PPI). This display is
essentially a polar diagram, with the transmitting
ship’s position at the center. Images of target
echoes are received and displayed at their
relative bearings, and at their distance from the
PPI center.

With a continuous display of the images of
targets, the motion of targets is also displayed.

See the figure on the next page for a
comparison of actual situation and radar picture.

How Radar Determines Bearing

The bearing to a target found by the radar is
determined by the direction in which the radar
antenna is pointing when it emits an electronic
pulse and then receives a returning echo. Each
time the antenna rotates pulses are transmitted
in the full 360 degree circle, each pulse at a
slightly different bearing from the previous one.

v

Targets

A

D

A

Heading Line

Range and bearing
to a target, relative

D

to own ship, are
readable on the
screen.

B

(A) Bird's eye view
of situation

C

Own ship
(radar)

B

(B) Radar picture of (A)

C

Own ship
at center

Note: The radar
screen does not
discriminate "bow"
or "stern."

vi

1.1 Control Description

1. OPERATION

TrackDisk

Shifts cursor, EBL,

VRM; selects items

on menus.

Opens/closes

the menu.

Turns EBL

on/off.

Decreases

the range.

Adjusts receiver

sensitivity.

Suppresses

rain clutter.

Echo trails

on/off.

Adjusts LCD tone

and brilliance.

MENU

GAIN

TRAIL ZOOM

TONE

EBL

FTC

GUARD

HM OFF

VRM

RING

RANGE

STC

SHIFT

TX

POWER

Activates/disables
the guard zone.
Press with [MENU]
to hide heading
marker.

Turns VRM on/off.
Press with [EBL] to
turn range rings
on/off.

Increases the
range.

Suppresses sea
clutter.

Shifts the display.

Zoom feature
on/off.

Toggles between
TRANSMIT and
STAND-BY.

Turns power
on/off.

Figure 1-1 Controls

1

1.2 Indications and Markers

Range
Range ring
interval

Zoom

(flashing)

Watchman

Guard
zone

Cursor

VRM

0.5
ZOOM
WATCHMAN

1.5

NM

3M TRAIL

G (IN)

FTC

ES

Target trails setting
Guard alarm (IN or OUT)
Rain clutter suppressor

IR

Echo stretch

Interference rejector

EBL

Heading line

Range rings

EBL bearing

VRM range

EBL
VRM

45.0˚

NM

1.25

Figure 1-2 Indications and markers

291.5˚

0.73

NM

Range and bearing
to cursor

2

1.3 Turning the Radar On/Off

1.5 LCD Tone and Brilliance

The [POWER] key turns the radar on/o f f. When
turning on the power, the co nt rol panel lights and
the timer displays the time remaining for warm
up of the magnetron (device which t r ansmits
radar pulses), counting down fro m 1:00 to 0:00.

Quick Start

Provided that the radar was once in use with
the transmitter tube (magnetron) still warm,
you can turn on the radar into TRANSMIT
status without the one-minute stand-by.
If the power switch has been turned off by
mistake and you want to restart the radar
promptly do the following:

1. Press the [POWER] key not later than five
seconds after power-off.

2. Press the [TX] key. The radar is restored
for full operation.

1.4 Transmitting, Stand-by

1. Press the [TONE] key. The dialogue s hown
in Figure 1-3 appears.

TONE: 12

▲

LOW HIGH

BRILL: 3

LOW ▼ ▲ HIGH

▲

Figure 1-3 Dialogue for adjustment of

LCD tone and brilliance

2. Press or or the [TONE] key to adjust
tone; ▲ or ▼ to adjust brilliance.

The dialogue for adjustment of tone and
brilliance is automatically erased when there is
no TrackDisk operation for about 10 seconds. To
erase it more quickly, press the [TONE] key after
making the adjustment.

After the power is turned on and the mag net ron
has warmed up, ST-BY (Stand-By ) appears at
the screen center, indicating the radar i s ready t o
transmit radar pulses.

Press the [TX] key to transmit. Echoes appear in
four levels of digitized v ideo ac cording to echo
strength. Note that when a target is beneath a
marker (VRM, EBL, heading marker, range ring)
the part of the marker where the target lies is
displayed in reverse video.

Note: If you press the [TX] key before the
indication ST-BY appears, the buzzer sounds
and the radar does not transmit pulses.

When you won’t be using the radar for an
extended period, but you want to keep it in a
state of readiness, press the [TX] key t o set t he
radar in stand-by.

1.6 Selecting the Range

The range selected automatically determines the
range ring interval, the number of range rings
and pulse repetition rate.

Press the [+] or [-] key to select a range. The
range and range ring interval appear at the top
left corner on the screen.

Range

Range ring
interval

Figure 1-4 Location of range and range

ring interval indications

6.0

2.0

NM

045.0°

3.35

NM

3

1.7 Receiver Sensitivity

The [GAIN] key adjusts t he sensitivity of the
receiver. It works in precisely t he same manner
as the volume control of a broadcast receiver,
amplifying the signals received.

Note: The dialogues for adjusting sensitivity are
automatically erase d w hen t here is no TrackDisk
operation for 10 seconds. To erase them quicker,
press the [GAIN] key after completing the setting.

You can adjust the sensitivity manually, or let the
unit do it automatically. In either case, the proper
setting is such that the background noise is just
visible on the screen. Adj ust the sensit ivity on t he
highest range since the bac kgr ound noise is
clearer on that range.

If you set up for too little sensitivity, weak echoes
may be missed. On the other hand excessive
sensitivity y ields t oo much background noise;
weak targets may be missed beca use of the po or
contrast between desired echo es and the
background noise on the displ ay.

Automatic adjustment of sensitivity

1. Press the [G AIN] key once or twice to display
the screen shown in Figure 1-5.

AUTO GAIN MOD
LOW HIGH

1 2 3

Figure 1-5 Dialogue for automatic

adjustment of gain

1.8 Suppressing Se a Clutter

In rough weather, returns from the sea surface
are received over several miles aro und own ship
and mask nearby targets. This situation can be
improved by properly using the [STC] key.

If the setting is too low, target s w ill be hidden in
the clutter, while if it is set too high, both sea
clutter and targets will disappear fro m the display .
In most cases adjust the key until clutter has
disappeared to leeward, but a l itt le is still visible
windward.

A common mistake is too over-adjust t he [ ST C]
key so that the surface clutter is completely
removed. By setting up for maximum S T C effect,
you will see how danger ous this can be; a dark
zone will be created near the center of the
screen, causing a loss of close-in target s. This
dark zone is even more dangerous if the
sensitivity has not been properly adjusted.
Always leave a littl e surf ace clutter visible on the
screen. If no clutter is observed (on very cal m
waters), turn off the circuit.

2. Press or to set level desired: 1, Low; 2,
Normal; 3, High.

Manual adjustment of sensitivity

1. Transmit t he radar on long range.

MAN GAIN MOD
LOW HIGH

32

Figure 1-6 Dialogue for manual

adjustment of gain

2. Press the [G AIN] key once or twice to display
the screen shown in Figure 1-6.

3. Press

 or  to set level desired. 61 levels

are available.

Sea clutter at

screen center

STC adjusted;

sea clutter suppressed

Figure 1-7 Appearance of sea clutter

4

Automatic sea clutter control

1. Press the [S TC] key once or twice to show
the dialogue shown in Figure 1-8.

AUTO STC MOD
LOW HIGH

1 2 3

Figure 1-8 Dialogue for automatic

adjustment of STC

2. Press or to set level desired: 1, Low; 2,
Normal; 3, High.

Manual adjustment of sea clutter
control

1. Press the [S TC] key once or twice to display
the dialogue shown in Figure 1-9.

MAN STC MOD
LOW HIGH

32

Figure 1-9 Dialogue for manual

adjustment of STC

2. Press  or  to set level desired. 61 levels
are available.

Note: The dialogues for adjusting STC are
automatically erase d w hen there is no TrackDisk
operation for 10 seconds. To erase them quicker,
press the [STC] key after completing the setting.

1.9 Suppressing Rain

Clutter

In adverse weather, clouds, rain or snow
produce spray-like spurious echoes which impair
target detection over a long distance. These
echoes can be suppressed by t urning on the
[FTC] key. FTC appears at t he t op right corner
on the screen when the FTC circuit is on.

Rain clutter

at screen center

FTC adjusted;

rain clutter suppressed

Figure 1-10 Appearance of

rain clutter

1.10 Range Rings

The range rings are the concentric circles around
own ship and they provide an esti mat ed of target
range. The selected range scale automatically
determines the number of rings an d t heir i nt erval
is displayed at the upper-le ft corner on the
screen.

To turn the range rings on or off, press the [EBL]
and [VRM] keys together.

1.11 Cursor

The cursor is always displayed and functions to
measure the range and bearing to a target .
Operate the TrackDisk to pla ce t he cursor on the
inside edge of the target for range or center o f
the target for bearing. The range and bearing to
the cursor appear at the bottom right corner on
the display.

6.0

NM

2.0

Target
Cursor

045.0°

3.35

NM

Range and
bearing to
cursor

Figure 1-11 How to measure range and

bearing with the cursor

5

1.12 Heading Marker

The heading marker indicates the ship’s heading and it is t he solid line which appears at zero
degrees on the bearing scale.

To temporarily erase the head ing marker to look at targets exist i ng dead ahead of own ship, press
the [MENU] and [GUA R D] keys together. Releas e t he keys to display the marker again.

1.13 Menu Operation

The menu contains ten fu nct ions which normally do not require frequent adjustment i n everyday
operation. Basic menu operation is as below.

Basic menu operation

1. Press the [MENU] key t o display the menu.

PRESS
ITEM,

1
2
3
4
5
6

Press ▲ or
switch between menus.

PRESS
ITEM,

7
8

9
10

▼/▲

TO SELECT MENU

▲

▲

TO CHANGE SETTING.

/

ECHO STRETCH
INT. REJECT
NAV DATA
VIDEO
WATCHMAN

DIMMER

▲

/

DSPL ON STBY
TRAIL TIME

TRAIL BRILL
RANGE (NM)

RVS NOM

at page boundaries to

▼

▼/▲

TO SELECT MENU

▲

TO CHANGE SETTING.

ON OFF

ON OFF

ON

OFF

OFF

5M 10M 20M

0 1 2 3

NAV OFF
CONT 30S

1M 3M 6M
LOW HIGH

1/8 1/4 1/2 3/4 1 1.5
2 3 4 6 8 12 16

Default settings in highlight.

Figure 1-12 Menus

2. Press ▲ or ▼ to select item.

3. Press

4. Press the [MENU] key to register optio n and close the menu.

6

!

or " to select option.

Table 1-1 Menu description

Menu Item Description

1 ECHO STRETCH Stretches echoes in the range direction.
2 INT. REJECT Suppresses radar interference.
3 NAV DATA Turns navigation data on/off.
4 VIDEO Displays echoes in black or white.
5 WATCHMAN Selects transmitting interval.
6 DIMMER Adjusts control panel brilliance.
7 DSPL ON STBY Turns navigation data display in standby on/off.
8 TRAIL TIME Select trail time (target echo plotting interval).

9 TRAIL BRILL Selects echo trail brilliance.
10 RANGE Selects range to use.

1.14 Control Panel Brilliance

1. Press the [MENU] key.

2. Select DIMMER.

3. Select level desired; 3 is the highest level of
illumination.

4. Press the [MENU] key.

1.15 Measuring the Range

The bearing to a target can be measured by the
range rings, by the cursor and by the VRM
(Variable Range Marker).

Measuring range by the range rings

Count the number of rings between the center
of the display and the target. Check the range
ring interval and judge the distance of the echo
from the inner edge of the nearest ring.

Measuring range by VRM

1. Press the [VRM] key to turn on the VRM.

2. Within 10 seconds after turning on the VRM;
that is, while "VRM" is highlighted, press ▲
or ▼ to place the VRM on the inside edge
of the target.

3. Check the VRM readout at the bottom left

corner on the screen.

To erase the VRM, press and hold down the
[VRM] key until the VRM disappears.

Note: The VRM is "frozen" on the display when
the [VRM] key is pressed a second time, or 10
seconds elapses without pressing ▲ or
When the VRM is fixed on the screen "VRM" is
not highlighted.

NM

6.0

2.0

Target

Cursor

VRM

▼.

NM

045.0°

2.42

NM

Cursor
range

VRM

2.42

VRM
range

Figure 1-13 How to measure range by

the cursor and VRM

7

1.16 Measuring the Bearing

1.17 Shifting the Display

The bearing to a target can be measured by
using the cursor or the EBL.

Measuring bearing by the EBL

1. Press the [EBL] key to turn on the EBL.

2. Within 10 seconds after turning on the EBL;
that is, while "EBL" is highlighted, press
or

"

to bisect the target with EBL.

3. Check the EBL re adout at the bottom left

corner on the screen.

To erase the EBL, press and hold down the
[EBL] key until the EBL disappears.

Note: The EBL is "frozen" on the screen when
the [EBL] key is pressed a secon d t i me, or 10

!

seconds elapses without press ing

or ".
When the EBL is fixed on the screen "EBL" is
not highlighted.

6.0

NM

2.0

Target

Cursor

EBL

!

Your vessel's position can be shifted backward
by 1/3 of the range to increase the forward
range without changing the range or size of
targets.

Press the [SHIFT] key to turn the shifted display
on/off.

Press

[SHIFT]

Normal display Shifted display

Figure 1-15 Shifting the display

1.18 Zoom

The zoom feature allows y ou t o double the size
of the area between your vessel and any
location within the current range to take a closer
look at an area of interest.

EBL

45.0°

EBL
bearing

045.0°

3.35

NM

Cursor
bearing

Figure 1-14 Measuring bearing by the

cursor and the EBL

1. Select location with the cursor.

2. Press the [ZOOM] key.

ZOOM on (flashing)

ZOOM

Cursor

Cursor

1) Place cursor
where desired.

Press

[ZOOM]

2) Press [ZOOM].

Figure 1-16 Zoom function

3. To turn off the zoom function, press the
[ZOOM] key again.

Note 1: The zoom feature is inoperative when
the display is shifted.

Note 2: Zoom function is not available on 0.125
(1/8) nm range.

8

1.19 Target Trails

1.20 Guard Alarm Zone

Target trails are simulated afterglow of target
echoes that represent their movements relative
to own ship.

3M TRAIL

Trail time (3 min),
echo trail ON (TRAIL)

Figure 1-17 Target trails

Starting target trail

Press the [TRAIL] key to start the echo tr ai l
function. "TRAIL" and the target trail time
selected appear at the top right corner o n t he
screen. Then, afterglow starts extend in g from a ll
targets.

Canceling target trail

Press the [TRAIL] key to erase target trails and
target trail indications.

The guard alarm allows the oper at or t o set t he
desired range and bearing for a gu ard zone.
When ships, islands, landmasses, etc. violate
the guard zone an audible a larm sounds to call
the operator’s attention. Th e alarm w ill sou nd on
targets entering or exiting the zone depending
on zone status after setting the alar m.

CAUTION

The alarm should not be relied upon as the

*

sole means for detecting possible collision
situations.

STC, FTC and GAIN controls should be

*

properly adjusted to be sure the alarm
system does not overlook target echoes

How guard zone type is determined

After the guard zone is set, the radar starts
searching for targets inside the guard zone for
about 8 to 12 seconds. When it fini shes
searching it displays t he results of the search as
G (IN) or G (OUT), at the top right corner on the
screen.

.

Trail time

1. Press the [M ENU] key.

2. Select TRAIL TIME (on page 2 of the menu).

3. Select t a rget t r ail t ime desired; continuous,
30 seconds, 1, 3 or 6 min as appropriate.

4. Press the [M ENU] key.

Trail brilliance

1. Press the [M ENU] key.

2. Select TRAIL BRILL (on page 2 of the
menu).

3. Select HI GH or LOW as appropriate.

4. Press the [M ENU] key.

G (IN): When no target exists in the zone, "G
(IN)" appears. The audible alar m sounds t o
targets which enter the guard zone.

G (OUT): When there are targets in the guard
zone, the screen shows "G (OUT)". The a udible
alarm sounds on all targ et s which exist in the
guard zone.

(a) Inward target alarm (b) Outward target alarm

Figure 1-18 Inward and outward alarms

9

Setting a guard zone

Silencing the audible alarm

1. Operate the TrackDisk to place the cursor at
the top left corner of the zone and press the
[GUARD] key.

2. Operate the TrackDisk to place the cursor at
the bottom right corner of the zone and
press the [GUARD] key.

Asterisk blinking

Mentally create
the guard zone to set.

GUARD

Guard
zone
to set

Guard
zone

Drag cursor
here.

1) Drag cursor to
top left corner of
zone and press
[GUARD].

* GUARD

* GUARD

Drag cursor
here.

When a target violates the guard zone, the
target flashes and the audible alarm sounds.
You can silence the audible alarm by pressing
the [GUARD] key. When this is done, GUARD,
displayed in reverse video, replaces G (IN) or G
(OUT) and the guard zone is displayed in
reverse video. This means the audible alarm is
temporarily deactivated. Press the key again to
reactivate the alarm.

Canceling the guard zone and guard
alarm

Press and hold down the [GUARD] key more
than two seconds to erase the guard zone.

1.21 Interference Rejector

Mutual radar interference may occur in the
vicinity of another shipborne radar operating in
the same frequency band (9 GHz). It is seen on
the screen as a number of bright spikes either in
irregular patterns or in the form of usually
curved spoke-like dotted lines extending from
the center to the edge of the picture. This type of
interference can be reduced by activating the
interference rejector circuit. "IR" appears at the
top right corner when the interference rejector
circuit is on.

Guard zone completed.

2) Drag cursor to
bottom right corner
of zone and press
[GUARD].

Figure 1-19 How to set a guard zone

3. About 10 seconds later "GUARD" replace
G(IN) or G(OUT).

Note:

When the radar range is less than one
half of the guard zone range, the guard zone
disappears and the indication "UP RNG"
replaces G (IN) or G (OUT). If this happens,
raise the range to redisplay the guard zone.

1. Press the [MENU] key.

2. Select INT REJECT.

3. Select ON or OFF.

4. Press the [MENU] key.

Figure 1-20 Radar interference

10

1.22 Echo Stretch

1.23 Watchman

On long ranges target echoes tend to shrink in
the range direction, making them difficult to see.
On short and medium ranges such as 1.5, 3 and
6 nm range scales, the same sized targets get
smaller on screen as they approach own ship.
This is due to the inherent property of the
radiation pattern produced by the antenna. To
enhance target video, use the echo stretch
feature.

Echo stretch
ON

ES

Echo

Echo
stretched
in range
direction

Echo stretch OFF Echo stretch ON

Figure 1-21 Echo stretch

The watchman function periodically transmits
the radar for about one minute to check for
targets in a guard zone. If it finds change in the
zone from the previous transmission it sounds
the audible alarm, cancels the watchman
function and transmits the radar continuously.
This feature is useful when you do not need to
observe the radar continuously but want to be
alerted to radar targets in a specific area,
namely, the guard zone. When the radar starts
transmitting, the buzzer sounds to alert the
operator

Tx

1 min

Watchman
starts.

St-by

5, 10 or
20 min

* Timer appears and countdowns

time to Tx when 1:00 remains

Tx

* *

1 min

St-by

5, 10 or
20 min

in ST-BY.

Figure 1-22 How watchman works

1. Press the [MENU] key.

2. Select ECHO STRETCH.

3. Select ON or OFF.

4. Press the [MENU] key.

ES appears at the top right corner on the screen
when the echo stretch feature is on.

Note 1:

target pips but also returns from sea surface,
rain and radar interference. For this reason,
make sure that these types of interference have
been sufficiently suppressed before activating
the echo stretch feature.

Note 2:

ranges between 0.125 and 0.75 nautical miles.

Echo stretch magnifies not only small

Echo stretch is not available on the

Turning watchman on/off

1. Set a guard zone.

2. Press the [MENU] key.

3. Select WATCHMAN.

4. Select transmitting interval, or turn
watchman off as appropriate.

5. Press the [MENU] key.

"WATCHMAN" appears at the top left corner on
the screen when the watchman function ison.

Note:

If no guard zone is set, the buzzer sounds
when the radar starts transmitting to alert the
operator.

Canceling watchman

Press any key at any time. If done while
transmitting, watchman is disabled and the
normal display appears. In stand-by, the timer
appears and counts down from one minute, and
then the radar goes into stand-by.

11

1.24 Navigation Data

1.25 Displa ying Navigat ion

With navigation data input in NME A 0183 for mat,
navigation data can be disp l ayed at the screen
bottom.

Navigation data include s position, course,
speed, and range and bearin g t o destination
waypoint (if set on navaid).

Waypoint is shown on the screen by a “lollipop
mark,” a dashed ring which is connected to the
screen center (own position) by a dash ed line.
You may turn it off or on by pressing [FT C] and
[SHIFT] together.

NM

6.0

2.0

Waypoint
mark

Data During Stand-by

Navigation data may be displayed during stand­by (requires external sensors) as follows:

1. Press the [M ENU] key.

2. Select DSPL ON STBY.

3. Select NAV.

4. Press the [M ENU] key

WP

215.5°M

12.5NM

CSE SPD

210.5° 12KT
LL

34°42.25' N
135°24.12' E

36378.1

TD

59096.4

TEMP

18.5°C

WP

17.0°

M

LL

135° 19.22'

EBL

45.0°

VRM

2.42

Bearing and range to waypoint
Bearing shown as magnetic bearing (M)
or true bearing (T)

Own ship position

*

2.6

NM

34° 38.99'

NM

N
E

CSE

18.0°

SPD

4 .3

255.0°

3.35

M

KT

NM

Figure 1-23 Sample navigation

data display

Turning on the navigation data
display

1. Press the [M ENU] key.

2. Select NAV DATA.

3. Select ON.

Course

Speed

DEPTH

1 2 5

M

Figure 1-24 Sample navigation data

screen shown during stand-by

Note: Nav data can be accepted from two
sources: navigator and video sounder. When
two of the same type of equipme nt is out put ting
data and it is not the same, the tw o set s of data
are alternately displayed automatically.

Unit of measurement for depth and
water temperature

The unit of measurement for dept h and w at er
temperature (external sensor requ ired) can be
selected with the [EBL] key in t he sequence of
Meters/Centigrade, Feet/Fahrenheit,
Fathoms/Centigrade. See notes on next page
for further information.

4. Press the [MENU] key.

12

Note 1: External sensor mu st be capable of
outputting such data to select it on this radar.

Note 2: A location is blank when there is no

corresponding data.

1.27 Selecting Ranges to Use

This radar has 13 ranges, some you may not
require. You can select th e ranges to use as
follows:

Note 3: To receive data fr om mult iple
equipment, all data must be combined into one
data line with a data-mixing device.

1.26 Echoes in Black or White

The default setting displays echoes in black on
a white background. However, you may reverse
this arrangement as shown below. Note that the
default setting, echoes in black, is restored
when the power is turned off.

1. Press the [MENU] key.

2. Select VIDEO.

3. Select RVS.

4. Press the [MENU] key.

1. Press the [MENU] key.

2. Select RANGE (on page 2 of the menu).

3. Select range to use and press t he [ EB L]
key.

4. Press the [MEN U] key.

13

14

2. RADAR OBSERVATION

)

m

2.1 General

Minimum and maximum ranges

Minimum range

The minimum range is defined by the shortest
distance at which, using a scale of 1.5 or 0.75
nm, a target having an echoing area of 10 m
still shown separate from the point representing
the antenna position.

It is mainly dependent on the pulselength,
antenna height, and signal processing such as
main bang suppression and digital quantization.
It is a good practice to use a shorter range scale
as far as it gives favorable definition or clarity of
picture.

Maximum range

The maximum detecting range of the radar,
Rmax, varies considerably depending on
several factors such as the height of the
antenna above the waterline, the height of the
target above the sea, the size, shape and
material of the target, and the atmospheric
conditions.

Under normal atmospheric conditions, the
maximum range is equal to the radar horizon or
a little shorter. The radar horizon is longer than
the optical one by about 6% because of the
diffraction property of the radar signal. The
Rmax is given in the following equation.

R

= 2.2 x (h1 + h2

max

where Rmax: radar horizon (nautical miles)

h1: antenna height (m)
h2: target height (m)

Radar horizon

Optical horizon

Figure 2-1 Radar horizon

For example, if the height of the antenna above
the waterline is 9 meters and the height of the
target is 16 meters, the maximum radar range
is;

R

= 2.2 x (9 + 16 ) = 2.2 x (3 + 4) = 15.4 n

max

2

is

It should be noted that the detection range is
reduced by precipitation (which absorbs the
radar signal).

Radar resolution

There are two important factors in radar resolu­tion (discrimination): bearing resolution and
range resolution.

Bearing resolution

Bearing resolution is the ability of the radar to
display as separate pips the echoes received
from two targets which are at the same range
and close together. It is proportional to the
antenna length and reciprocally proportional to
the wavelength. The length of the antenna
radiator should be chosen for a bearing
resolution better than 2.5 degrees.

Range resolution

Range resolution is the ability to display as
separate pips the echoes received from two
targets which are on the same bearing and
close to each other. This is determined by
pulselength only. Practically, a 0.08
microsecond pulse offers the discrimination
better than 35 m as do so with all FURUNO
radars.

Test targets for determining the range and
bearing resolution are radar reflectors having an

2

echoing area of 10 m

.

Bearing accuracy

One of the most important features of the radar
is how accurately the bearing of a target can be
measured. The accuracy of bearing
measurement basically depends on the
narrowness of the radar beam. However, the
bearing is usually taken relative to the ship’s
heading, and thus, proper adjustment of the
heading line at installation is an important factor
in ensuring bearing accuracy. To minimize error
when measuring the bearing of a target, put the
target echo at the extreme position on the
screen by selecting a suitable range.

15

Range measurement

;

Sidelobe echoes

Measurement of the range to a target is also a
very important function of the radar. Generally,
there are two means of measuring range: the
fixed range rings and the variable range marker
(VRM). The fixed range rings appear on the
screen with a predetermined interval and
provide a rough estimate of the range to a target.
The variable range marker’s diameter is
increased or decreased so that the marker
touches the inner edge of the target, allowing
the operator to obtain more accurate range
measurements.

2.2 False Echoes

Occasionally echo signals appear on the screen
at positions where there is no target or
disappear even if there are targets. They are,
however, recognized if you understand the
reason why they are

displayed. Typical false echoes are shown
below.

Multiple echoes

Multiple echoes occur when a transmitted pulse
returns from a solid object like a large ship,
bridge, or breakwater. A second, a third or more
echoes may be observed on the display at
double, triple or other multiples of the actual
range of the target as shown below. Multiple
reflection echoes can be reduced and often
removed by decreasing the gain (sensitivity) or
properly adjusting the [STC] control.

True
echo

Every time the radar pulse is transmitted, some
radiation escapes on each side of the beam,
called sidelobes. If a target exists where it can
be detected by the side lobes as well as the
main lobe, the side echoes may be represented
on both sides of the true echo at the same range.
Sidelobes show usually only on short ranges
and from strong targets. They can be reduced
through careful reduction of the gain or proper
adjustment of the [STC] control.

Target A

Target B
(Spurious)

Target B
(True)

Figure 2-3 Sidelobe echoes

Virtual image

A relatively large target close to your ship may
be represented at two positions on the screen.
One of them is the true echo directly reflected by
the target and the other is a false echo which is
caused by the mirror effect of a large object on
or

close to your ship as shown in the figure below.
If your ship comes close to a large metal bridge,
for example, such a false echo may temporarily
be seen on the screen.

Target ship

Own
ship

True

echo

Own ship

Target

Multiple
echo

Figure 2-2 Multiple echoes

Mirror image

of target ship

False
echo

Figure 2-4 Virtual image

16

Shadow sectors

Funnels, stacks, masts, or derricks in the path of
the antenna block the radar beam. If the angle
subtended at the antenna is more than a few
degrees, a non-detecting sector may be
produced. Within this sector targets can not be
detected.

Radar
antenna

When the range to the SART is reduced to
about 1 nm, the radar display may show also the
12 responses generated during the fast sweeps.
These additional dot responses, which also are
equally spaced by 0.64 nm, will be interspersed
with the original line of 12 dots. Th ey will appea r
slightly weaker and smaller than the original
dots.

Screen B: When SART
is close

1.5 NM

Lines of 12 dots
are displayed in
concentric arcs.

Echo of
SART

Position of
SART

Screen A: When SART
is distant

Echo of SART

24 NM

Radar antenna
beamwidth

Radar
mast

Shadow sector

Figure 2-5 Shadow sector s

2.3 SART (Sear ch and Rescue Transponder)

Note: The SART information below is excerpted

from IMO SN/Circ 197 Operation of Marine
Radar for SART Detection.

A Search and Rescue Transponder (SART)
may be triggered by any X-Band (3 cm) radar
within a range of approximately 8 nm. Each
radar pulse received causes it to transmit a
response which is swept repetitively across the
complete radar frequency band. When
interrogated , it first sweeps rapidly (0.4 µs)
through the band before beginning a relatively
slow sweep (7.5 µs) through the band back to
the starting frequency. This process is repeated
for a total of twelve complete cycles. At some
point in each sweep, the SART frequency will
match that of the interrogating radar and be
within the pass band of the radar receiver. If the
SART is within range, the frequency match
during each of the 12 slow sweeps will produce
a response on the radar display, thus a line of
12 dots equally spaced by about 0.64 nautical
miles will be shown.

Own ship's
position

9500 MHz
9200 MHz

Sweep start

SART mark
length

Sweep time

7.5 µs
95 µs

Low speed sweep signal

High speed sweep signal

Own ship's
position

Radar receiver
bandwidth

Position of
SART

Figure 2-6 Appearance of S A RT signal

on the radar display

General procedure for detecting
SART response

1. Use the range scale of 6 or 12 nm as the
spacing between the SART responses is
about 0.6 nm (1125 m) to distinguish the
SART.

2. Turn off the automatic clutter suppression.

3. Turn off the Interference Rejector.

General remarks on receiving SART

SART range errors

When responses from only the 12 low frequency
sweeps are visible (when the SART is at a
range greater than about 1 nm), the position at
which the first dot is displayed may be as much
as 0.64 nm beyond the true position of the
SART. When the range closes so that the fast
sweep responses are seen also, the first of
these will be no more than 150 meters beyond
the true position.

17

Radar bandwidth

FTC control

This is normally matched to the radar
pulselength and is usually switched with the
range scale and the associated pulselength.
Narrow bandwidths of 3-5 MHz are used with
long pulses on long range and wide bandwidths
of 10-25 MHz with short pulses on short ranges.

Any radar bandwidth of less than 5 MHz will
attenuate the SART signal slightly, so it is
preferable to use a medium bandwidth to ensure
optimum detection of the SART.

Radar side lobes

As the SART is approached, sidelobes from the
radar antenna may show the SART responses
as a series of arcs or concentric rings. These
can be removed by the use of the anti-clutter
sea control although it may be operationally
useful to observe the sidelobes as they may be
easier to detect in clutter conditions and also
they will confirm that the SART is near to the
ship.

This should be used normally (to break up areas
of rain) when trying to detect a SART response
which, being a series of dots, is not affected by
the action of the anti-clutter rain circuitry. Note
that Racon responses, which are often in the
form of a long flash, will be affected by the use
of this control.

Some sets have automatic/manual anti-clutter
rain control facilities in which case the operator
should switch to manual.

When the range to the SART is reduced to
about 1 nm, the radar display may show also the
12 responses generated during the fast sweeps.
These additional dot responses, which also are
equally spaced by 0.64 nm, will be interspersed
with the original line of 12 dots. They will appear
slightly weaker and smaller than the original
dots.

General procedure for detecting
SART response

Gain

For maximum range SART detection the normal
gain setting for long range detection should be
used, that is, with background noise speckle
visible.

STC control

For optimum range SART detection, this control
should be set to the minimum. Care should be
exercised as wanted target in sea clutter may be
obscured. Note also that in clutter conditions the
first few dots of the SART response may not be
detectable, irrespective of the setting of the
anti-clutter sea control. In this case, the position
of the SART may be estimated by measuring

9.5 nm miles from the furthest dot back towards
own ship.

Some sets have automatic/manual anti-clutter
sea control facilities in which case the operator
should switch to manual.

1. Use the range scale of 6 or 12 nm as the
spacing between the SART responses is
about 0.6 nm (1125 m) to distinguish the
SART.

2. Turn off the automatic clutter suppression.

3. Turn off the Interference Rejector.

General remarks on receiving SART

SART range errors

When responses from only the 12 low frequency
sweeps are visible (when the SART is at a
range greater than about 1 nm), the position at
which the first dot is displayed may be as much
as 0.64 nm beyond the true position of the
SART. When the range closes so that the fast
sweep responses are seen also, the first of
these will be no more than 150 meters beyond
the true position.

Radar bandwidth

18

This is normally matched to the radar
pulselength and is usually switched with the
range scale and the associated pulselength.
Narrow bandwidths of 3-5 MHz are used with
long pulses on long range and wide bandwidths
of 10-25 MHz with short pulses on short ranges.

Any radar bandwidth of less than 5 MHz will
attenuate the SART signal slightly, so it is
preferable to use a medium bandwidth to ensure
optimum detection of the SART.

Radar side lobes

As the SART is approached, sidelobes from the
radar antenna may show the SART responses
as a series of arcs or concentric rings. These
can be removed by the use of the anti-clutter
sea control although it may be operationally
useful to observe the sidelobes as they may be
easier to detect in clutter conditions and also
they will confirm that the SART is near to the
ship.

Gain

For maximum range SART detection the normal
gain setting for long range detection should be
used, that is, with background noise speckle
visible.

FTC control

This should be used normally (to break up areas
of rain) when trying to detect a SART response
which, being a series of dots, is not affected by
the action of the anti-clutter rain circuitry. Note
that Racon responses, which are often in the
form of a long flash, will be affected by the use
of this control.

Some sets have automatic/manual anti-clutter
rain control facilities in which case the operator
should switch to manual.

2.4 Racon (Radar Beacon)

A racon is a radar transponder which emits a
characteristic signal when triggered by a ship’s
radar (usually only the 3 centimeter band). The
signal may be emitted on the same frequency
as that of the triggering radar, in which case it is
superimposed on the ship's radar display
automatically.

STC control

For optimum range SART detection, this control
should be set to the minimum. Care should be
exercised as wanted target in sea clutter may be
obscured. Note also that in clutter conditions the
first few dots of the SART response may not be
detectable, irrespective of the setting of the
anti-clutter sea control. In this case, the position
of the SART may be estimated by measuring

9.5 nm miles from the furthest dot back towards
own ship.

Some sets have automatic/manual anti-clutter
sea control facilities in which case the operator
should switch to manual.

The racon signal appears on the PPI as a radial
line originating at a point just beyond the
position of the radar beacon or as a Morse code
signal (figure below) displayed radially from just
beyond the beacon.

Racon

Figure 2-7 Appearance of Racon signal

on the radar display

19

20

3. MAINTENANCE, TROUBLESHOOTING

3.1 Maintenance

Regular maintenance is important for good performance. A maintenance program should be
established and should at least include the items listed in Table 3-1.

Table 3-1 Maintenance program

Period Item Check point Action

3 to 6
months

6 months
to 1 year

Fixing bolts for
antenna unit

Antenna unit
cleanliness

Antenna unit
cover

LCD The LCD will, in time,

Display unit
connectors

Check for corrosion and if
tightly fastened.

Check for foreign material.
(Foreign material on the
antenna unit can cause a
considerable drop in
sensitivity.)

Check for cracks. Permanent
damage to the unit’s circuitry
will result if water leaks inside

accumulate a coating of dust
which tends to dim the picture.

Check for tight connection and
corrosion.

Replace corroded bolts. Coat new
bolts with anticorrosive sealant.

Clean the antenna unit with a
freshwater-moistened cloth.
Alcohol may be used. Do not use
commercial cleaners to clean the
antenna unit; they can remove
paint and markings.

If a crack is found, it should be
temporarily repaired by using a
small amount of sealing compound
or adhesive. The unit should then
be brought to your dealer for
permanent repairs.

Wipe the LCD gently with a soft
cloth. Do not use commercial
cleaners to clean the LCD; they can
remove paint and markings.

If corroded, see your dealer about
replacement.

3.2 Replacing the Fuse

The fuse (5A) in the power cable protects the equipment against reverse polarity of ship’s mains,
overcurrent, and equipment fault. If the fuse blows, find the cause before replacing it. Never use a
fuse rated for more than 5A, since overfusing can cause serious damage to the equipment and void
the warranty.

21

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SPECIFICATIONS OF MARINE RADAR

MODEL 1622

1. GENERAL

(1) Indication System PPI Daylight display, raster scan, 4 tones in monochrome
(2) Range, Pulselength (PL) & Pulse Repetition Rate (PRR)

Range (nm) 0.125, 0.25, 0.5, 0.75 1, 1.5, 2 3, 4, 6, 8, 12, 16
Pulse Length 0.12 µs (short) 0.3 µs (medium) 0.8 µs (long)
Pulse Repetition Rate 2100 Hz nominal 1200 Hz nominal 600 Hz nominal

(3) Range Resolution Better than 50 m
(4) Bearing Discrimination Within 7.7
(5) Minimum Range 41 m
(6) Bearing Accuracy Within 1
(7) Range Ring Accuracy 0.9 % of range or 8 m, whichever is the greater

2. SCANNER UNIT

(1) Radiator Micro-strip
(2) Polarization Horizontal
(3) Antenna Rotation Speed 24 rpm nominal
(4) Radiator Length 34 cm
(5) Horizontal Beamwidth Less than 6.2
(6) Vertical Beamwidth 25
(7) Sidelobe Attenuation Less than -20 dB

3. TRANSCEIVER MODULE

(1) Frequency 9410 MHz ±30MHz (X band)
(2) Modulation P0N

°

°

°

°

(3) Peak Output Power 2.2 kW
(4) Modulator FET Switching Method
(5) Intermediate Frequency 60 MHz
(6) Tuning Automatic
(7) Receiver Front End MIC (Microwave IC)
(8) Bandwidth 7 MHz
(9) Duplexer Circulator with diode limiter
(10) Time of Heat-up 1-min. approx.

SP - 1

4. DISPLAY UNIT

(1) Picture Tube 6 inch rectangular monochrome LCD
(2) Display Pixels 240(H) x 320(V) dots, Effective radar display area: 240 x 240 dots
(3) Range, Range Interval, Number of Rings

Range (NM) 0.125 0.25 0.5 0.75 1 1.5 2 3 4 6 8 12 16
Ring Interval (NM) 0.0625 0.125 0.125 0.25 0.25 0.5 0.5 1 1 2 2 3 4
Number of Rings 2 2 4 3 4 3 4 3 4 3 4 4 4

(4) Markers Heading Line, Bearing Scale, Range Rings,

Variable Range Marker (VRM), Electronic Bearing Line (EBL),
Tuning Bar, Cursor, Parallel Cursor, Alarm Zone,
Waypoint Mark (navigation input required),
North Mark (heading sensor input required)

(5) Alphanumeric Indications Range, Range Ring Interval, Display Mode (HU),

Interference Rejection(IR), Variable Range Marker (VRM),

Electronic Bearing Line (EBL), Stand-by (ST-BY),
Guard Alarm (G(IN), G(OUT), UP RANGE), Echo Stretch (ES),
Range and Bearing to Cursor, Bearing or L/L Position,
Echo Tailing (TRAIL), Trailing Time, Trailing Elapsed Time,
Watchman (WATCHMAN), Zoomed Display (ZOOM),
Navigation Data (navigation input required),
Heading (HDC, heading sensor input required)
(6) Input Data NMEA0183 (Ver.1.5/2.0)

Own ship’s position: GGA>RMA>RMC> GLL

Speed: RMA>RMC>VTG>VBW

Heading (True): HDT>HDG

Heading (Magnetic): HDM>HDG

*1

>HDM*1

*1

>HDT*1
Course (True): RMA>RMC>VTG
Course (Magnetic): VTG>RMA
Waypoint(Range, Bearing): RMB>BWC>BWR
Loran time difference: RMA>GLC>GTD
Water depth: DPT >DBK>DBS>DBT
Water temperature: MTW
*1: calculate by magnetic drift.

5. ENVIRONMENTAL CONDITI ON

(1) Ambient Temperature Scanner Unit: -25°C to +70°C
Display Unit: -15°C to +55°C
(2) Relative Humidity 95 % or less at +40°C

SP - 2

(3) Waterproofing

Scanner Unit IPX6
Display Unit IPX5

(4) Bearing Vibration IEC60945

6. POWER SUPPLY
(1) Power Supply 12/24 VDC: 3.2/1.3 A, 35 W approx. (Watchman: 8 W or less)

7. DIMENSIONS AND MASS

See the Outline Drawings

8. COATING COLOR

(1) Display Unit Panel: N3.0

Chassis: 2.5GY5/1.5

(2) Scanner Unit Cover: N9.5, Bottom: 2.5PB 3.5/10

9. COMPASS SAFE DISTANCE

(1) Display Unit Standard: 0.65 m Steering: 0.50 m
(2) Scanner Unit Standard: 1.25 m Steering: 0.95 m

SP - 3

INDEX

B

Bearing mea surement......................................8

C

Control description...........................................1

Cursor..............................................................5

D

Depth unit ......................................................12

DIMMER ke y....................................................7

E

EBL (Electronic Bearing Line)...........................8

EBL key...........................................................8

Echo hue........................................................13

Echo stretch...................................................11

F

False echoes..................................................16

FTC..................................................................5

Fuse replacement...........................................21

G

GAIN key .........................................................4

Guard alarm.....................................................9

GUARD key ...................................................10

H

Heading marker................................................6

I

Indications........................................................2

Interference rejector.......................................10

M

Magnetron repl ac em ent..................................22

Maintenance ..................................................21

Menu operation ................................................6

Multiple echoes ..............................................16

N

Nav data........................................................12

P

POWER key ....................................................3

R

Range

measurement...............................................7

minimum and maximum .............................15

selection.......................................................3

Range measurement .......................................7

Range rings .....................................................5

Ranges to use................................................13

S

SART.............................................................17

Shadow sector...............................................17

SHIFT key .......................................................8

Sidelobe echoes ............................................16

STC key...........................................................4

Synchro belt replacement...............................22

T

Target trails......................................................9

TONE ke y........................................................3

TRAIL key........................................................9

Troubleshooting .............................................22

TX key.............................................................3

V

Virtual image..................................................16

VRM (Variable Range Marker) .........................7

VRM key..........................................................7

W

Watchman..................................................... 11

Water temperature unit...................................12

Z

Index-1

ZOOM key.......................................................8