JRC NTG-420 User manual

7ZPRR0001
INSTALLATION MANUAL
FOR
THE NTG-420 SOLID STATE
TRANSMITTER-RECEIVER
Document No. 7ZPRR0001
APR. 2016

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Table of Contents
1. SELECTING THE INSTALLATION POSITION..................................................................2
2. INSTALLATION PROCEDURE..........................................................................................7
3. CONNECTING THE INSTALLATION CABLE .................................................................10
4. INSTALLATION OF SOLID STATE TRANSMITTER-RECEIVER (NTG-420)..................12
5. SOLID STATE TRANSMITTER-RECEIVER(NTG-420) WIRING .....................................13
6. INSTALLATION CABLE AND WAVEGUIDE ...................................................................17
APPENDIX ..........................................................................................................................20
MAXIMUM PERMISSIBLE EXPOSURE(MPE) CALCULATION..........................................29
FCC CAUTION....................................................................................................................31
IC (INDUTRY CANADA)......................................................................................................31

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- Preface -
This instruction manual describes installation method of the NTG-420
Transmitter-Receiver. This manual describes radar system configuration with
X-band Radar Antenna and NCD-2247-1B PC type radar monitor display as an
example.
1. Selecting the installation position
1) Physical selection criteria
•Install the antenna at the center of the mast on the keel line.
•If the antenna cannot be installed at the above position for some reason, the
amount of deviation must be minimized. And, reinforce the mount base
and the platform and take precautions to protect the antenna from vibration
and impact at the installation position.
•To avoid the radiating section coming in contact with other installed objects
while it is rotating, ensure that there is at least 200 millimeters from the
swing circle (turning radius) to other installed objects (Fig.1-1). The swing
circle of the X-band Radar Antenna is as shown in Table 1-1.
Fig.1-1 Installation of antenna
Table 1-1 Swing circle
Antenna Swing circle
X-band Radar Antenna 2825mm
min-height
必要最小高さ
min-offset
オフセット最小
Over 200mm
200mm
以上
reinforcing member
補強材

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•Avoid having a rope or signal flag from winding around the radiating section
thereby preventing it from rotating.
•Avoid the effects of dust and heat caused by smoke from a chimney.
•When determining the appropriate antenna height and installation location,
take into consideration the reduction of vibration, the strength of the hull and
the antenna mount base, and maintenance properties.
•Provide for maintenance space: platform, safety link, hand rail, steps, etc.
The lower edge of a radar antenna should be a minimum of 500 mm above
any safety rail.
•When installing the antenna, select a location where there are the fewest
structural objects in the surrounding area so that the capability to drive the
motor will not be depressed by the non-equability wind which is likely to
rotate the antenna.
2) Electrical selection criteria
•The installation height of the antenna relates to the maximum detection
distance. The higher is the better. (However, if it is too high, radio wave
energy greatly attenuates above the antenna's vertical beam width (the
point -3dB from the peak of the main lobe). As a result, it is difficult to
detect a close-in target. Sea clutter also increases. Determine the
installation height by taking into consideration the weight, maximum length
of the cable, and maintenance after installation.
•If the installation height of the antenna is low, it is difficult to detect a long
distance target. The ship's mast, derrick, and construction objects interfere
with radiating beam causing the range that cannot be viewed on the radar
display to increase.
Generally, the lowest antenna installation position is supposed to be on the
A-B line shown in Fig.1-2. In the case of the radar antenna, 2θequals 20°.
Specifically, the antenna position is normally elevated so that the building
etc do not interfere with radiating beam. The inside of A point might be blind
area due to antenna beam does not propagation. So, if near distance should
be covered, antenna installation position must be considered carefully.
θ = 10°
L
A
B
θ
Sea surface Blind area
Building etc.
Fig.1-2 Antenna installation height vs Vertical beam width

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•If it is considered that sufficient installation height cannot be provided when
the antenna is installed directly on the roof of the building, use a mounting
rack or radar mast (Fig.1-3). Normally, when the antenna installation
height is less than 2 meters from the roof of the building, provide a
mounting rack assembled at an angle frame to install the antenna. When
the antenna installation height is 2 meters or higher from the roof of the
building, provide a cylindrical radar mast to install the antenna. Consider
the convenience of the service staff who take care of installation,
maintenance, adjustment, and repair of the antenna by providing adequate
footholds to the mounting rack and the radar mast.
Fig.1-3 Mounting rack and mast for the antenna
•When installing the antenna, select a location where there are the fewest
structural objects in the surrounding area so that false images which
interfere with target detection will not be generated by signal reflection from
other antennas, equipments, and cargos. Only as a guide, note that
structural objects should not exist within the range of the vertical beam
width (Fig.1-4).
Vertical beam width of X-band Radar Antenna: Approx. 20°(±10.0°when
the height of the radiating section is 0°).
Fig.1-4 Antenna and the surrounding structural objects
ビーム幅
Beam
width
Installation
Installation

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•When installing two or more antennas, antennas in close proximity should
have a minimum vertical elevation separation angle of 20 and a minimum
vertical separation of 1m where possible, so that those antennas do not
enter each other's vertical beam width range.
1m (min)
20°(min)
Fig.1-5 Installing two or more antennas
•To avoid interference with other equipment and to prevent radio noise from
generating, do not place the VHF antenna, AIS/GPS antenna, and
VSAT/INMARSAT's dome within the range of the vertical beam width.
* If there is a concern that structural objects existing within the vertical beam
width may generate false images, equip the structural objects with a radio
wave absorber. (There are two types of absorbers: broadband type
having no specific resonant frequency and narrowband type which can
absorb a band with a specific frequency. Use those where applicable.)
Furthermore, it is effective to install a metal reflector, which reflects radio
waves upwardly, between the antenna and a structural object so that the
radar's radio wave will not directly come in contact with the structural
object.
When the structural objects exist in the surrounding area of Antenna unit,
the false echo may appear. The sector blank function is effective to
reduce the signal reflection from the structural objects. Because of it can
stop transmission. Therefore, it may reduce the false echo appearance.
Note: Because most radio wave absorbers have poor durability, some
must be replaced every year. When installing a reflector, the
area to the rear of the reflector becomes a blind sector.
Therefore, minimize the size of the reflector.
When the sector blank function set to on, ensure a sufficient
view field in the surveillance area.
* The above procedures for selecting an antenna installation position are
described based on the radar's antenna. Comprehensively select the
antenna position by considering other antennas' installation procedure
manual, building tower mast structure, strength of the selected position,
and vibration.
3) Confirmation during test run

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If the antenna vibrates a lot during test run, try to reduce or prevent
vibration by reinforcing the antenna mount base or using wire stays
attached to the radar mast.
4) Others
•The design of the mounting platform for the antenna should take into
account the vibration requirements defined by IEC 60945.
Vibration
Frequency
2 to 13.2Hz
13.2 to 100Hz
Amplitude +/-1mm +/-10%
Acceleration 7m/s
2
constant
•All installations should facilitate protection of equipment, including cabling,
from damage.
The cables should be kept as short as possible to minimize attenuation of
the signal.
•Crossing of cables should be done at right angles(90°) to minimize
magnetic field coupling.
•Eliminating the interference on frequencies used for marine
communications due to operation of the radar. All cables of the radar are to
be run away from the cables of radio equipment. (ex. Radiotelephone.
Communications receiver and direction finder, etc.) Especially inter-wiring
cables between antenna unit and display unit of the radar should not be run
parallel with the cables of radio equipment.
•Cable should not be exposed sharp bends.
•The grounding of equipment units should be carried out according to this
manual.
5) After installation
After you have completed the installation work, check and test the
installation work with customer(s) and confirm with each other.

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2. Installation procedure
1) Precautions for transporting and storing the antenna
•An antenna is a heavy load. Be very careful about handling it.
•Do not allow the antenna fall on its side while it is stored or being installed.
•Do not apply rope to the antenna in the way that squeezes or deforms the
radiating section.
•When hoisting the antenna by a crane, do not hoist it by attaching a belt or
a rope only to the antenna's radiating section as shown in Fig.2-1.
•When lifting the antenna（Fig.2-2）:
Wrap a cloth around the antenna's support section located at the bottom of
the radiator, and then attach a belt to it to lift the antenna.
Fig.2-1 Improper way to hoist
Fig.2-2 Lifting the Antenna
2) Installation procedures
a) Maintain a flat level surface on which to install the antenna.
•Use sufficiently thick steel material and reinforcement material for the
antenna's installation surface (mount base) to reduce vibration and
impact. Keep the mount base flat and smooth.
•If there is a partial gap between the mount base and the antenna
chassis's legs, work on the installation surface so that it becomes flat
and smooth. If a gap exists and the antenna is tightly clamped, the
chassis will distort and become damaged by vibration.
Wrap a cloth

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b) Avoid using vibration-proof rubber and resin
•Do not insert an elastic body, such as vibration-proof rubber or resin,
between the mount base and the antenna chassis' legs. If rubber or resin
is inserted, the amplitude of vibration increases, resulting in the possibility
of damage to the antenna. Furthermore, if installation bolts become loose
due to deterioration of rubber or resin, the antenna may be damaged or fall
from its mount.
3) Installation and clamping method
a) Installation direction
•Installation should be done so that the cable gland side is oriented
accessibility by maintenance staffs.
b) Bolts, nuts and tightening torque to be used
•Use stainless steel bolts for the antenna and uniformly tighten all of the
bolts using double nuts for each bolt so that the antenna will not
become loose (Table 2-1).
•Although the length of the bolt will differ according to the thickness of
the mount base, use a bolt long enough so that more than 4 millimeters
of thread protrudes beyond the double nuts after the double nuts have
been tightened.
Table 2-1 Length of antenna mounting bolts and tightening torque
Antenna
Unit
Thickness of
Mount Base
(mm) Bolt Torque (N-m)
12 M10×55(mm) SUS304 40
c) Use of washer and corrosion-resistant measures
•At the location where a bolt's head or nut comes in contact with the
antenna chassis' legs and the mount base, insert a plain washer which
fits the bolt; and, at the location where the nut comes in contact with the
plain washer, insert a spring washer, and then securely tighten the nuts
(Fig.2-3).
•To prevent corrosion due to the contacts between different metals, such
as the antenna chassis' legs, installation surface, bolts, nuts, etc., cover
the bolt's head and nuts with sealant (Fig.2-3).

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Fig.2-3 Use of washer and corrosion-resistant measures
d) Grounding and corrosion-resistant measures
•Ground the antenna chassis and the installation surface (hull) by using
an earth line. Apply sealant to the connection portion of the earth line
to prevent corrosion and damage by vibration (Fig.2-4).
Fig.2-4 Grounding and corrosion-resistant measures