Sea Tel ST94-21 User manual

Sea Tel, Inc.
4030 Nelson Avenue
Concord, CA 94520
Tel: [phone]
Fax: [phone]
Web: http://www.cobham.com/seatel
Sea Tel Europe
Unit 1, Orion Industrial Centre
Wide Lane, Swaythling
Southampton, UK S0 18 2HJ
Tel: [phone]
Fax: [phone]
Web: http://www.cobham.com/seatel
Sea Tel Inc is also doing business as Cobham SATCOM - Maritime
July 1, 2015 Document. No. 136465 Revision A1
INSTALLATION AND OPERATION MANUAL
FOR SEA TEL MODEL
ST94-21 DUAL C/QUAD KU-BAND TVRO ANTENNA
EAR Controlled - ECCN EAR99
EAR Controlled - ECCN EAR99
This technical data is subject to US Government export control in accordance with
the Export Administration Regulations. Export of this data to any foreign country
or disclosure of this data to a Non-US person may be a violation of Federal law.

ii
Sea Tel Marine Stabilized Antenna systems are manufactured in the United States of America.
Sea Tel is an ISO 9001:2008 registered company.
Certificate Number 13690 issued March 14, 2011.
R&TTE
CE
The Series 97 Family of Marine Stabilized Antenna Pedestals with DAC-97 Antenna Control
Unit complied with the requirements of European Norms and European Standards EN 60945
(1997) and prETS 300 339 (1998-03) on July 20, 1999. Sea Tel document number 119360
European Union Declaration of Conformity for Marine Navigational Equipment is available on
request.
Copyright Notice
Copyright © 2012 Sea Tel Inc All Rights Reserved. The information contained in this document is proprietary to Sea Tel,
Inc.. This document may not be reproduced or distributed in any form without prior written consent of Sea Tel, Inc. The
information in this document is subject to change without notice. Sea Tel Inc, is also doing business as Cobham Antenna
Systems.
This document has been registered with the U.S. Copyright Office.
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iii
Revision History
REV
ECO#
Date
Description
By
A
N/A
April 11, 2012
Initial Production Release
MDN
A1
N/A
January 20, 2014
Update installation text and installation arrangement drawing
MDN
A2
N/A
July 1, 2015
Clerical corrections in specifications
MDN
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Table of Contents
v
1. INTRODUCTION ..........................................................................................................................................................................................1-1
1.1. GENERAL DESCRIPTION OF SYSTEM ........................................................................................................................................................... 1-1
1.2. PURPOSE ..........................................................................................................................................................................................................1-1
1.3. SYSTEM COMPONENTS ................................................................................................................................................................................. 1-1
1.4. DUAL ANTENNA CONFIGURATION............................................................................................................................................................. 1-2
1.5. DUAL ANTENNA ARBITRATOR.....................................................................................................................................................................1-3
1.6. GENERAL SCOPE OF THIS MANUAL.............................................................................................................................................................. 1-3
1.7. QUICK OVERVIEW OF CONTENTS................................................................................................................................................................ 1-3
2. SITE SURVEY..................................................................................................................................................................................................2-1
2.1. SITE SELECTION ABOARD THE SHIP .......................................................................................................................................................... 2-1
2.2. ANTENNA SHADOWING (BLOCKAGE)AND RF INTERFERENCE .............................................................................................................. 2-1
2.3. MOUNTING FOUNDATION ........................................................................................................................................................................... 2-2
2.3.1. Mounting on Deck or Deckhouse......................................................................................................................................2-2
2.3.2. ADE Mounting Considerations...........................................................................................................................................2-2
2.3.3. Sizing of the support pedestal............................................................................................................................................2-2
2.4. MOUNTING HEIGHT AND FORE-AFT LOCATION ..................................................................................................................................... 2-3
2.5. MAST CONFIGURATIONS .............................................................................................................................................................................2-4
2.5.1. Vertical Masts ..............................................................................................................................................................................2-4
2.5.2. Raked Masts..................................................................................................................................................................................2-4
2.5.3. Girder Masts .................................................................................................................................................................................2-5
2.5.4. Truss Mast .....................................................................................................................................................................................2-5
2.6. SAFE ACCESS TO THE ADE.......................................................................................................................................................................... 2-5
2.7. BELOW DECKS EQUIPMENT LOCATION ..................................................................................................................................................... 2-5
2.8. CABLES.............................................................................................................................................................................................................2-6
2.8.1. ADE/BDE Coaxial Cables........................................................................................................................................................2-6
2.8.2. Antenna Power Cable ..............................................................................................................................................................2-6
2.8.3. Air Conditioner Power Cable ...............................................................................................................................................2-6
2.8.4. ACU Power Cable/Outlet........................................................................................................................................................2-7
2.8.5. Gyro Compass Cable................................................................................................................................................................2-7
2.8.6. Grounding......................................................................................................................................................................................2-7
3. INSTALLATION.............................................................................................................................................................................................3-1
3.1. GENERAL CAUTIONS &WARNINGS ........................................................................................................................................................... 3-1
3.2. SITE SELECTION ABOARD SHIP ................................................................................................................................................................... 3-2
3.3. PREPARATION .................................................................................................................................................................................................3-2
3.4. OPENING YOUR CRATES ................................................................................................................................................................................ 3-2
3.4.1. Location of Items inside the Crates.................................................................................................................................3-3
3.4.2. Base Frame and Reflector Crate........................................................................................................................................3-3
3.4.3. Pedestal Crate .............................................................................................................................................................................3-4
3.4.4. Radome Crate:.............................................................................................................................................................................3-5
3.5. UNPACKING THE BASE FRAME AND REFLECTOR CRATE ......................................................................................................................... 3-5
3.6. UNPACKING THE PEDESTAL CRATE ............................................................................................................................................................ 3-8
3.7. UNPACKING THE RADOME CRATE: ...........................................................................................................................................................3-10
3.8. ASSEMBLING THE ADE...............................................................................................................................................................................3-11
3.8.1. Preparing for Assembly of the ADE ..............................................................................................................................3-11
3.8.2. Sub-assemble the Base Frame Assembly...................................................................................................................3-11
3.8.3. Sub-assemble the bottom panels of the 144” Radome Assembly................................................................3-12
3.8.4. Sub-assemble the upper panels of the 144” Radome Assembly ...................................................................3-16
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3.8.5. Sub-assemble the bottom panels onto the base frame..................................................................................... 3-20
3.8.6. Sub-assemble the Antenna Pedestal ........................................................................................................................... 3-21
3.8.7. Close the 144” Radome Assembly ................................................................................................................................ 3-23
3.9. INSTALLING THE ADE................................................................................................................................................................................3-24
3.9.1. Hoist..............................................................................................................................................................................................3-24
3.9.2. Install Antenna/Radome/Baseframe............................................................................................................................ 3-25
3.10. INSTALLING THE BELOW DECKS EQUIPMENT. .......................................................................................................................................3-25
3.10.1. General Cautions & Warnings..........................................................................................................................................3-25
3.10.2. Preparing BDE Location......................................................................................................................................................3-25
3.10.3. Installing the Below Deck Equipment......................................................................................................................... 3-25
3.11. CONNECTING THE BELOW DECKS EQUIPMENT .....................................................................................................................................3-25
3.11.1. Connecting the ADE AC Power Cable......................................................................................................................... 3-26
3.11.2. Connecting the BDE AC Power Cables....................................................................................................................... 3-26
3.11.3. Connecting the ADE IF Coaxes...................................................................................................................................... 3-26
3.11.4. Antenna Control Unit Connections.............................................................................................................................. 3-26
3.11.5. 13Terminal Mounting Strip (TMS) Connections.................................................................................................... 3-26
3.11.6. Other BDE connections ...................................................................................................................................................... 3-27
3.12. FINAL CHECKS..............................................................................................................................................................................................3-27
3.12.1. Visual/Electrical inspection............................................................................................................................................... 3-27
3.12.2. Electrical - Double check wiring connections......................................................................................................... 3-27
3.13. POWER-UP...................................................................................................................................................................................................3-28
3.14. CABLE TERMINATIONS...............................................................................................................................................................................3-28
3.14.1. At The Radome........................................................................................................................................................................3-28
3.14.2. ACU & TMS ................................................................................................................................................................................ 3-28
3.14.3. Other BDE Equipment .........................................................................................................................................................3-28
3.15. FINAL ASSEMBLY.........................................................................................................................................................................................3-28
3.15.1. Remove Stow Braces/Restraints..................................................................................................................................... 3-28
3.15.2. Verify all assembly and Wiring connections............................................................................................................ 3-28
3.16. POWER-UP THE ADE.................................................................................................................................................................................3-28
3.16.1. Initialization.............................................................................................................................................................................. 3-28
3.16.2. Home Flag Position............................................................................................................................................................... 3-29
3.16.3. BDE ................................................................................................................................................................................................3-29
3.16.4. Balancing the Antenna........................................................................................................................................................3-29
3.16.5. Fine Balance and Monitoring Motor Drive Torque .............................................................................................. 3-29
3.17. SETUP ............................................................................................................................................................................................................3-31
4. BASIC SETUP OF THE ACU ..................................................................................................................................................................4-1
4.1. OPERATOR SETTINGS.....................................................................................................................................................................................4-1
4.2. SETUP PARAMETER DISPLAY AND ENTRY MENUS...................................................................................................................................4-1
4.3. TRACK DISP .................................................................................................................................................................................................4-1
4.4. ACU FACTORY DEFAULT PARAMETER SETTINGS –STXXX-21 SERIES ANTENNAS.......................................................................4-2
5. SETUP – SHIPS GYRO COMPASS...................................................................................................................................................... 5-1
5.1. GYRO TYPE ...................................................................................................................................................................................................5-1
5.2. UPDATING THE GYRO TYPE PARAMETER ................................................................................................................................................5-1
5.3. IF THERE IS NO SHIPS GYRO COMPASS ....................................................................................................................................................5-1
6. DETERMINE INTERNAL TRACKING RECEIVER SETTINGS............................................................................................ 6-1
6.1. IF TRACKING FREQUENCY ............................................................................................................................................................................6-1
6.2. BAUD RATE......................................................................................................................................................................................................6-1
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6.3. FEC ..................................................................................................................................................................................................................6-2
6.3.1. DVB Receiver................................................................................................................................................................................6-2
6.4. TONE ................................................................................................................................................................................................................6-2
6.4.1. TVRO Applications.....................................................................................................................................................................6-2
6.5. VOLT.................................................................................................................................................................................................................6-2
6.5.1. TVRO Application .......................................................................................................................................................................6-2
6.6. NID..................................................................................................................................................................................................................6-3
7. SETUP – HOME FLAG OFFSET.............................................................................................................................................................7-1
7.1. ELECTRONIC CALIBRATION OF RELATIVE ANTENNA POSITION (HOME FLAG OFFSET) ................................................................... 7-1
7.1.1. You Found a Large AZ TRIM value:..................................................................................................................................7-1
7.1.2. You Observe “Home” Pointing is LEFT of the Bow-line: .........................................................................................7-2
7.1.3. You Observe “Home” Pointing is RIGHT of the Bow-line: .....................................................................................7-2
7.1.4. To Enter the HFO value in the DAC_2202:...................................................................................................................7-3
8. SETUP – TARGETING................................................................................................................................................................................8-1
8.1. AUTO TRIM.................................................................................................................................................................................................8-1
8.2. MANUALLY OPTIMIZING TARGETING........................................................................................................................................................ 8-1
8.3. EL TRIM .........................................................................................................................................................................................................8-2
8.4. AZ TRIM........................................................................................................................................................................................................8-2
8.5. SAVE NEW PARAMETERS .....................................................................................................................................................................8-2
9. SETUP – SEARCHING................................................................................................................................................................................9-1
9.1. SEARCHING OPERATION ............................................................................................................................................................................... 9-1
9.1.1. Default Standard (Box) Search Pattern..........................................................................................................................9-1
9.1.2. Inclined Orbit Search Pattern.............................................................................................................................................9-2
9.1.3. No Gyro Search Pattern .........................................................................................................................................................9-3
9.2. CHANGING THE SEARCH PARAMETERS ...................................................................................................................................................... 9-4
9.2.1. AUTO THRES ................................................................................................................................................................................9-4
9.2.2. EL STEP SIZE ...............................................................................................................................................................................9-4
9.2.3. AZ STEP SIZE ..............................................................................................................................................................................9-4
9.2.4. STEP INTEGRAL..........................................................................................................................................................................9-4
9.2.5. SEARCH INC.................................................................................................................................................................................9-5
9.2.6. SEARCH LIMIT............................................................................................................................................................................9-5
9.2.7. SEARCH DELAY ...........................................................................................................................................................................9-5
9.2.8. SWEEP INC ...................................................................................................................................................................................9-5
9.3. SAVE NEW PARAMETERS .....................................................................................................................................................................9-5
10. SETUP – BLOCKAGE & RF RADIATION HAZARD ZONES ..............................................................................................10-1
10.1. RADIATION HAZARD AND BLOCKAGE MAPPING (AZ LIMIT PARAMETERS)...................................................................................10-1
11. SETUP...............................................................................................................................................................................................................11-1
11.1. OPERATOR SETTINGS ..................................................................................................................................................................................11-1
11.2. OPTIMIZING TARGETING (AUTO TRIM) .................................................................................................................................................11-1
11.3. OPTIMIZING TARGETING (MANUALLY)...................................................................................................................................................11-1
11.4. RADIATION HAZARD AND BLOCKAGE MAPPING (AZ LIMIT PARAMETERS)...................................................................................11-1
11.5. TX POLARITY SETUP ...................................................................................................................................................................................11-2
11.6. TRACK DISP...............................................................................................................................................................................................11-2
12. FUNCTIONAL TESTING .......................................................................................................................................................................12-1
12.1. ACU /ANTENNA SYSTEM CHECK ............................................................................................................................................................12-1
12.2. LATITUDE/LONGITUDE AUTO-UPDATE CHECK ......................................................................................................................................12-1
12.3. SHIP HEADING –GYRO COMPASS FOLLOWING CHECK .......................................................................................................................12-1
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12.4. AZIMUTH &ELEVATION DRIVE................................................................................................................................................................12-1
12.5. FOUR QUADRANT TRACKING TEST..........................................................................................................................................................12-1
12.6. BLOCKAGE SIMULATION TEST..................................................................................................................................................................12-2
13. MAINTENANCE AND TROUBLESHOOTING ........................................................................................................................... 13-1
13.1. WARRANTY INFORMATION .......................................................................................................................................................................13-1
13.2. RECOMMENDED PREVENTIVE MAINTENANCE .......................................................................................................................................13-1
13.2.1. Check ACU Parameters.......................................................................................................................................................13-1
13.2.2. Latitude/Longitude Auto-Update check..................................................................................................................... 13-1
13.2.3. Heading Following.................................................................................................................................................................13-1
13.2.4. Azimuth & Elevation Drive.................................................................................................................................................13-2
13.2.5. Test Tracking............................................................................................................................................................................13-2
13.2.6. Visual Inspection -Radome & Pedestal ................................................................................................................... 13-2
13.2.7. Mechanical Checks................................................................................................................................................................13-2
13.2.8. Check Balance..........................................................................................................................................................................13-2
13.2.9. Observe Antenna Initialization....................................................................................................................................... 13-2
13.3. 400MHZ MODEM CONFIGURATION .....................................................................................................................................................13-3
13.4. 400 MHZ LED INDICATORS ....................................................................................................................................................................13-4
13.5. 400 MHZ MODEM SIGNALS....................................................................................................................................................................13-4
13.5.1. Pedestal M&C...........................................................................................................................................................................13-4
13.5.2. Radio M&C.................................................................................................................................................................................13-5
13.5.3. Channel Identification ........................................................................................................................................................ 13-5
13.6. TROUBLESHOOTING 400MHZ MODEM COMMUNICATION FAULTS...............................................................................................13-6
13.6.1. 400MHz Modem Queries:.................................................................................................................................................. 13-6
13.6.2. Modem Query Methods ..................................................................................................................................................... 13-6
13.6.3. Isolating a 400 MHz Modem Fault Procedure:...................................................................................................... 13-8
13.7. TROUBLESHOOTING .................................................................................................................................................................................13-11
13.7.1. Theory Of Stabilization Operation ..............................................................................................................................13-11
13.7.2. ST-21 Series Dual C-Band OR Quad Ku-Band TVRO RF Flow .....................................................................13-11
13.7.3. Antenna Initialization (ST-21 Series).........................................................................................................................13-12
13.7.4. Troubleshooting using DacRemP ................................................................................................................................13-13
13.7.5. Antenna Loop Error Monitoring...................................................................................................................................13-14
13.7.6. Reference Sensor Monitoring........................................................................................................................................13-15
13.7.7. Open Loop Rate Sensor Monitoring...........................................................................................................................13-16
13.7.8. Open Loop Motor Test ......................................................................................................................................................13-17
13.7.9. To Disable/Enable DishScan®.......................................................................................................................................13-18
13.7.10. Satellite Reference Mode.................................................................................................................................................13-18
13.7.11. To Read/Decode an ACU Error Code 0008 (Pedestal Function Error): ...................................................13-18
13.7.12. Remote GPS LAT/LON Position: ....................................................................................................................................13-21
13.8. MAINTENANCE .........................................................................................................................................................................................13-22
13.8.1. Balancing the Antenna......................................................................................................................................................13-22
13.8.2. To Adjust Tilt:..........................................................................................................................................................................13-23
13.8.3. To Reset/Reinitialize the Antenna: ..............................................................................................................................13-24
13.9. PEDESTAL CONTROL UNIT CONFIGURATION -STXXX-21 SERIES............................................................................................... 13-25
13.9.1. To configure the PCU;........................................................................................................................................................13-25
13.9.2. MODEL CONFIGURATION NUMBERS......................................................................................................................13-25
13.10. ANTENNA STOWING PROCEDURE ......................................................................................................................................................... 13-26
14. ST94-21 TECHNICAL SPECIFICATIONS.................................................................................................................................. 14-1
14.1. 9497 ANTENNA REFLECTOR ....................................................................................................................................................................14-1
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14.2. FEED ASSEMBLIES........................................................................................................................................................................................14-1
14.2.1. TVRO-21 Dual C-Band / Quad Ku-Band Feed Assembly ....................................................................................14-1
14.3. STABILIZED ANTENNA PEDESTAL ASSEMBLY .........................................................................................................................................14-2
14.4. MK 2PEDESTAL CONTROL UNIT (PCU) ...............................................................................................................................................14-3
14.5. MK 2MOTOR DRIVER ENCLOSURE (MDE) ..........................................................................................................................................14-3
14.6. 400 MHZ BASE &PEDESTAL UNLIMITED AZIMUTH MODEMS (3 CHANNEL)...............................................................................14-4
14.7. 144” RADOME ASSEMBLY .........................................................................................................................................................................14-4
14.8. ENVIRONMENTAL CONDITIONS (ADE) ...................................................................................................................................................14-5
14.9. CABLES...........................................................................................................................................................................................................14-5
14.9.1. Antenna Control Cable (Provided from ACU-MUX)..............................................................................................14-5
14.9.2. Antenna L-Band TVRO IF Coax Cables (Customer Furnished) .......................................................................14-5
14.9.3. AC Power Cable (Pedestal & Rf Equipment).............................................................................................................14-5
14.9.4. Gyro Compass Interface Cable (Customer Furnished) ......................................................................................14-6
14.9.5. Fiber Optic Transmitter (CFE Optional)......................................................................................................................14-6
15. MODEL ST94-21 DRAWINGS............................................................................................................................................................15-1
15.1. MODEL ST94-21 SPECIFIC DRAWINGS ................................................................................................................................................15-1
15.2. STXXX-21 GENERAL DRAWINGS..............................................................................................................................................................15-1
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ST94-21 C/Ku-Band TVRO Introduction
1-1
1. Introduction
1.1. General Description of system
Your Series 00 system is a fully stabilized antenna that has been designed and manufactured so as to be inherently
reliable, easy to maintain, and simple to operate. Except for start-ups, or when changing to operate with different
transponders or satellites, the equipment essentially permits unattended operation.
1.2. Purpose
This shipboard Television Receive Only (TVRO) system provides you with satellite TV programming while in port or
underway. Your Antenna system will receive signals of adequately high E.I.R.P. levels (see the Specifications section of
this manual), in linear or circular polarization mode from any of the geosynchronous TV satellites at C-Band or Ku-band
frequencies (dependent upon currently installed feed assembly). This input will be distributed to all of your satellite TV
receivers which will provide the Audio/Video to your Televisions. Many satellites also provide CD quality audio
programming which may also be routed to your stereo equipment.
1.3. System Components
Your TVRO Antenna system consists of two major groups of equipment; an above-decks group and a below-decks
group. Each group is comprised of, but is not limited to, the items listed below. All equipment comprising the Above
Decks is incorporated inside the radome assembly and is integrated into a single operational entity. For inputs, this
system requires only an unobstructed line-of-sight view to the satellite, Gyro Compass input and AC electrical power.
Video and Audio outputs from your satellite receivers are available for distribution and monitoring.
For more information about these components, refer to the Basic System Information section of this manual.
A. Above-Decks Equipment (ADE) Group
1. Stabilized antenna pedestal
2. Antenna Reflector
3. Feed Assembly with LNB(s)
4. Radome Assembly
B. Below-Decks Equipment Group
5. Antenna Control Unit
6. 2 or 4 input Matrix Switch with desired number of outputs (one output to the ACU plus enough outputs for
the installed satellite receivers).
7. Satellite Video Receiver(s) & Television(s)
8. Control, RF and Video cables
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Introduction ST94-21 C/Ku-Band TVRO
1-2
Figure 1-1 TVRO Simplified Block Diagram
1.4. Dual Antenna Configuration
Sometimes, due to very large blockage conditions, you may need to install a dual antenna configuration to provide
uninterrupted services. Two full antenna systems are installed and the ACU control outputs are connected to an
arbitrator switch panel which then is connected to the below decks equipment. NOTE: The RXIF from EACH antenna
MUST be connected to the RF IN (J6) on the rear panel of its respective ACU then RFOUT (J7) is connected to the RXIF
input of the Dual Antenna Arbitrator. This connection scheme is required for ACU “A” to be able to control Antenna
“A” (and ONLY Antenna “A”) AND ACU “B” to be able to control Antenna “B” (and ONLY Antenna “B”).
You will program the blockage zone(s) for each of the two antennas (refer to Setup – Blockage Zones). The blockage
output from the ACU is fed to the Terminal Mounting Strip so that the output of each ACU can be connected to the
arbitrator panel to control it. The blockage output is available on SW2 terminal of the Terminal Mounting Strip to
provide a transistor “short” to ground when the antenna is within a blockage zone programmed into the ACU. When
not blocked the SW2 terminal will be an “open”.
When one antenna is blocked, its blockage output will command the arbitrator panel to switch services to the Satellite
TV receivers from that antenna to the other antenna. The arbitrator panel provides a logic latch to prevent excess
switching when the ship heading is yawing, therefore, causing if the antenna to be repeatedly blocked – unblocked –
blocked.
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ST94-21 C/Ku-Band TVRO Introduction
1-3
1.5. Dual Antenna Arbitrator
The Dual Antenna Arbitrator panel can pass LNB voltages (and handle 250-400 ma of current) and the RXIF signals on
the RX connections.
The blockage (SW2) output from the two terminal mounting strips (antenna “A” and antenna “B”) are wired through
the arbitrator panel to the satellite receiver distribution. When antenna “A” is blocked, the arbitrator PCB will toggle
the coax switches so that antenna “B” provides signal to the BDE distribution (multi-switch). When antenna “A” is no
longer blocked the arbitrator will do nothing (because it is a latch circuit). When antenna “B” is blocked the panel will
switch so that antenna “A” is again providing signal the BDE distribution.
1.6. General scope of this manual
This manual describes the Sea Tel Antenna (also called the Above Decks Equipment), its’ operation and installation.
Refer to the manual provided with your Antenna Control Unit for its’ installation and operating instructions.
1.7. Quick Overview of contents
The information in this manual is organized into chapters. Operation, basic system information, installation, setup,
functional testing, maintenance, specifications and drawings relating to this Antenna are all contained in this manual
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Introduction ST94-21 C/Ku-Band TVRO
1-4
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ST94-21 C/Ku-Band TVRO Site Survey
2-1
2. Site Survey
The objective of the Site survey is to find the best place to mount the antenna & the below decks equipment, the length and
routing of the cables and any other items or materials that are required to install the system and identify any other issues that
must be resolved before or during the installation.
2.1. Site Selection Aboard The Ship
The radome assembly should be installed at a location aboard ship where:
•The antenna has a clear line-of-sight to view as much of the sky (horizon to zenith at all bearings) as is
practical.
•X-Band (3cm) Navigational Radars:
•The ADE should be mounted more than 0.6 meters/2 feet from 2kW (24 km) radars
•The ADE should be mounted more than 2 meters/8 feet from 10kW (72 km) radars
•The ADE should be mounted more than 4 meters/12 feet from 160kW (250km) radars
•S-Band (10cm) Navigational Radars:
•If the ADE is/has C-Band it should be mounted more than 4 meters/12 feet from the S-band Radar.
•The ADE should not be mounted on the same plane as the ship's Radar, so that it is not directly in the Radar
beam path.
•The ADE should be mounted more than 2.5 meters/8 feet from any high power MF/HF antennas (<400W).
•The ADE should be mounted more than 4 meters/12 feet from any high power MF/HF antennas (1000W).
•The ADE should also be mounted more than 4 meters/12 feet from any short range (VHF/UHF) antennae.
•The ADE should be mounted more than 2.5 meters/8 feet away from any L-band satellite antenna.
•The ADE should be mounted more than 3 meters/10 feet away from any magnetic compass installations.
•The ADE should be mounted more than 2.5 meters/8 feet away from any GPS receiver antennae.
•Another consideration for any satellite antenna mounting is multi-path signals (reflection of the satellite
signal off of nearby surfaces arriving out of phase with the direct signal from the satellite) to the antenna.
This is particularly a problem for the onboard GPS, and/or the GPS based Satellite Compass.
•The Above Decks Equipment (ADE) and the Below Decks Equipment (BDE) should be positioned as close to
one another as possible. This is necessary to reduce the losses associated with long cable runs.
•This mounting platform must also be robust enough to withstand the forces exerted by full rated wind load
on the radome.
•The mounting location is robust enough that it will not flex or sway in ships motion and be sufficiently well
re-enforced to prevent flex and vibration forces from being exerted on the antenna and radome.
•If the radome is to be mounted on a raised pedestal, it MUST have adequate size, wall thickness and gussets
to prevent flexing or swaying in ships motion. In simple terms it must be robust.
If these conditions cannot be entirely satisfied, the site selection will inevitably be a “best” compromise between the
various considerations.
2.2. Antenna Shadowing (Blockage) and RF Interference
At the transmission frequencies of C and Ku band satellite antenna systems, any substantial structures in the way of
the beam path will cause significant degradation of the signal. Care should be taken to locate the ADE so that the ADE
has direct line-of-sight with the satellite without any structures in the beam path through the full 360 degree ships
turn. Wire rope stays, lifelines, small diameter handrails and other accessories may pass through the beam path in
limited numbers; however, even these relatively insignificant shadows can produce measurable signal loss at these
frequencies.
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Site Survey ST94-21 C/Ku-Band TVRO
2-2
2.3. Mounting Foundation
2.3.1. Mounting on Deck or Deckhouse
While mounting the ADE on a mast is a common solution to elevate the ADE far enough above the various
obstructions which create signal blockages, sometimes the best mounting position is on a deck or deckhouse
top. These installations are inherently stiffer than a mast installation, if for no other reason than the design of
the deck/deckhouse structure is prescribed by the ship’s classification society. In the deck/deckhouse design
rules, the minimum plating and stiffener guidelines are chosen to preclude high local vibration amplitudes.
Most installations will have a base frame with multiple attachment points around the perimeter of the base
frame to mount the Above Deck Equipment (ADE) onto a deck or deckhouse structure of the ship. The base
frame may be mounted using the supplied legs & braces to raise the ADE above the deck for radome hatch
access allow access into the radome. The base frame may be directly attached to the deck, in which case the
access panel in the floor of the base frame cannot be utilized. In this case the installation must allow acces
into the radome through a door in one of the side panels or an access opening directly under the hacth.
Some care must be taken to ensure the mounting pedestal is properly aligned with the stiffeners under the
deck plating.
Alternately, a specifically designed and stiffened mast may be used to mount the base frame above the deck;
this should only be attempted if sufficient deck space high on the ship is not available.
2.3.2. ADE Mounting Considerations
Mounting the radome directly on the deck, or platform prevents access to the hatch in the base of the
radome unless an opening is designed into the mounting surface to allow such entry. If there is no access to
the hatch the only way to service the antenna is to remove the radome top.
Ladder rungs must be provided on all mounting stanchions greater than 3-4 feet tall to allow footing for
personnel safety when entering the hatch of the radome.
The recommended cable passage is through the bottom (near center) of the radome base, down through the
ADE support pedestal (if used), through the deck and into the interior of the ship.
2.3.3. Sizing of the support pedestal
The following should be taken into account when choosing the height of a mounting support stand:
1. The height of the pedestal should be kept as short as possible, taking into account recommendations
given in other Sea Tel Guidelines.
2. The minimum height of the pedestal above a flat deck or platform to allow access into the radome
for maintenance should be 0.6 meters (24 inches).
3. The connection of the ADE mounting plate to the stanchion and the connection of the pedestal to
the ship should be properly braced with triangular gussets (see graphic above). Care should be taken
to align the pedestal gussets to the ship’s stiffeners as much as possible. Doublers or other
reinforcing plates should be considered to distribute the forces when under-deck stiffeners are
inadequate.
4. The diameter of the pedestal stanchion shall not be smaller than 100 millimeters (4 inches). Where
the ADE base diameter exceeds 1.5 meters (60 inches), additional stanchions (quantity greater than
3) should be placed rather than a single large stanchion.
5. Shear and bending should be taken into account in sizing the ADE mounting plate and associated
gussets.
6. Shear and bending must be taken into account when sizing the pedestal to ship connection.
7. All welding should be full penetration welds –V-groove welds with additional fillet welds – with
throats equivalent to the thickness of the thinnest base material.
8. For an ADE mounted greater than 0.6 meters (24 inches) above the ship’s structure, at least one (1)
foot rung should be added. Additional rungs should be added for every 0.3 meter (12 inches) of
pedestal height above the ship’s structure.
9. For an ADE mounted greater than 3 meters (9 feet) above the ship’s structure, a fully enclosing cage
should be included in way of the access ladder, starting 2.3 meters (7 feet) above the ship’s
structure.
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2.4. Mounting Height and Fore-Aft Location
Installations with mast or deck vibrations at frequencies between 2 and 15 Hertz have been identified by Sea Tel as
causing problems with the isolation systems of the ADE. Preventing problems prior to installation due to these
vibrations is one of the primary considerations in choosing where to mount the antenna.
In some installations, though, the combination of mounting height, fore-aft location and ship motion can impart
significant accelerations on the entire ADE. Installations where the ADE is situated high on the ship – usually at the
top of a mast – places the ADE is a position where the low frequency ship motion in roll and/or pitch creates two
accelerations – tangential and radial. These accelerations vary in a periodic function, out-of-phase from the ship
response to the wave motions.
Radial acceleration is the acceleration acting on the mass of the ADE pulling away from the center of the axis (roll or
pitch). In this sense, it would be a force trying to ‘pull’ the ADE away from the ship. We normally are not too
concerned with radial acceleration, since it must become far greater than gravity to have a detrimental effect on the
ADE.
Tangential acceleration is the acceleration acting on the mass of the ADE pulling across the center of the axis (roll or
pitch). This acceleration becomes a force trying to pull the ADE to the side. The tangential acceleration has an effect
on both the strength of the ADE pedestal and the tracking accuracy of the control algorithm.
The effect of tangential acceleration is felt by the structure of the ADE before it truly affects the tracking accuracy.
For instance, Sea Tel normally accepts that a tracking error of 0.1 degrees RMS at 0.5 G to be within acceptable error
margins. A 0.5 G tangential acceleration on the ADE means that ½ of the weight of the ADE is acting sideways on the
pedestal structure.
The higher up you mount the antenna above the pivot point of the ship the higher the tangential acceleration (g-
force) exerted on the antenna will be (see chart below). When the g-force exerted on the antenna is light, antenna
stabilization and overall performance will not be affected.
If the g-force exerted on the antenna is high enough (> 1 G), antenna stabilization and overall performance will be
affected.
If the g-force exerted on the antenna is excessive (1-2 Gs), the antenna will not maintain stabilization and may even
be physically damaged by the g-force.
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2.5. Mast Configurations
Sea Tel recommends the ADE be mounted on the ship in a location which has both a clear line-of-sight to the target
satellites in all potential azimuth/elevation ranges and sufficient support against vibration excitement. If possible,
mounting the ADE pedestal directly to ship deckhouse structures or other box stiffened structures is preferred.
However, in many cases, this imposes limits on the clear line-of-sight the antenna system has.
Often the solution for providing the full azimuth/elevation range the antenna needs is to mount the ADE on the ship’s
mast. Unfortunately, masts do not consider equipment masses in design and often have harmonic frequencies of their
own.
For these large systems, the mast for the ADE should be designed specifically for the ADE. Other equipment may be
mounted alongside, but the mast should be configured to accept the mass, loads and resonance of the ADE primarily.
The following sections describe various mast configurations and some considerations for mast design.
2.5.1. Vertical Masts
Vertical masts are a very ancient and common mast design. In essence, it is the mast derived from the sailing
mast, adapted for mounting the ever-increasing array of antennae ships need to communicate with the
world. This drawing of a Vertical mast shows
preferred mounting of the ADE center-line above
the plane of the radar, or as an alternate with the
ADE mounted below the plane of the radar signal,
as reasonably good installations of a satellite
antenna ADE.
Vertical masts are most commonly still found on
cargo ships – they are simple, inelegant and
functional. They are also fairly stiff against
torsional reaction and lateral vibrations, as long as
the ADE is mounted on a stiff pedestal near the
vertical centerline of the mast. If centerline
mounting is impractical or otherwise prohibited,
the mast platform the ADE is mounted on should be checked for torsional vibration about the centerline of
the mast and the orthogonal centerline of the platform.
If the estimated natural frequency of the mast or platform is less than 35 Hertz, the mast or platform should
be stiffened by the addition of deeper gussets under the platform or behind the mast.
2.5.2. Raked Masts
Raked masts are found on vessels where the style
or appearance of the entire vessel is important.
Again, the inclined mast is a direct descendant from
the masts of sailing ships – as ship owners wanted
their vessels to look more unique and less
utilitarian, they ‘raked’ the masts aft to make the
vessel appear capable of speed. This drawing
shows a raked mast, again with the preferred ADE
mounting above the radar and alternate with the
ADE below the radar.
Raked masts pose special problems in both
evaluating the mast for stiffness and mounting of
antennae. As can be seen in the drawing all
antennae must be mounted on platforms or other
horizontal structures in order to maintain the
vertical orientation of the antenna centerline. This
implies a secondary member which has a different
natural frequency than the raked mast natural frequency. In order to reduce the mass of these platforms,
they tend to be less stiff than the main box structure of the raked mast. Thus, they will have lower natural
frequencies than the raked mast itself. Unfortunately, the vibratory forces will act through the stiff structure
of the raked mast and excite these lighter platforms, to the detriment of the antenna.
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2.5.3. Girder Masts
Girder masts are large platforms atop a pair of
columns. Just like girder constructions in buildings,
they are relatively stiff athwart ship – in their
primary axis – but less stiff longitudinally and
torsionally. An example of a girder mast is shown in
this drawing, with the preferred ADE mounting
outboard and above the radar directly on one of the
columns and alternate with the ADE centered on
the girder above the plane of the radar.
The greatest weakness of girder masts is in torsion –
where the girder beam twists about its vertical
centerline axis. As with all mast designs discussed so far, mounting the antenna in line with the vertical
support structure will reduce the vibration tendencies. Mounting the antenna directly above the girder
columns provides ample support to the antenna pedestal and locates the antenna weight where it will
influence the natural frequency of the mast the least.
2.5.4. Truss Mast
Truss masts are a variant on the girder mast
concept. Rather than a pair of columns supporting a
girder beam, the construction is a framework of
tubular members supporting a platform on which
the antennae and other equipment is mounted. A
typical truss mast is shown in this photograph.
Like a girder mast, truss masts are especially stiff in
the athwart ship direction. Unlike a girder mast, the
truss can be made to be nearly as stiff in the
longitudinal direction. Truss masts are particularly
difficult to estimate the natural frequency – since a
correct modeling includes both the truss structure
of the supports and the plate/diaphragm structure
of the platform. In general, though, the following
guidelines apply when determining the adequate
support for mounting an antenna on a truss mast:
1. Antenna ADE pedestal gussets should align
with platform stiffeners which are at least
200 millimeters in depth and 10 millimeters in thickness.
2. When possible, the antenna ADE pedestal column should align with a vertical truss support.
3. For every 100 Kilograms of ADE weight over 250 Kilograms, the depth of the platform stiffeners
should be increased by 50 millimeters and thickness by 2 millimeters.
Sea Tel does not have a recommended arrangement for a truss mast – the variability of truss mast designs
means that each installation needs to be evaluated separately.
2.6. Safe Access to the ADE
Safe access to the ADE should be provided. Provisions of the ship’s Safety Management System with regard to men
aloft should be reviewed and agreed with all personnel prior to the installation. Installations greater than 3 meters
above the deck (or where the access starts at a deck less than 1 meter in width) without cages around the access
ladder shall be provided with means to latch a safety harness to a fixed horizontal bar or ring.
The access hatch for the ADE shall be oriented aft, or inboard, when practical. In any case, the orientation of the ADE
access hatch shall comply with the SMS guidelines onboard the ship. Nets and other safety rigging under the ADE
during servicing should be rigged to catch falling tools, components or fasteners.
2.7. Below Decks Equipment Location
The Antenna Control Unit, Terminal Mounting Strip and Base Modem Panel are all standard 19” rack mount, therefore,
preferred installation of these items would be in such a rack. The ACU mounts from the front of the rack. The
Terminal Mounting Strip and Base Modem Panel mount on the rear of the rack.
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The Satellite Modem, router, VIOP adapter(s), telephone equipment, fax machine, computers and any other associated
equipment should also be properly mounted for shipboard use.
Plans to allow access to the rear of the ACU should be considered.
2.8. Cables
During the site survey, walk the path that the cables will be installed along. Pay particular attention to how cables will
be installed all along the path, what obstacles will have to have be routed around, difficulties that will be encountered
and the overall length of the cables. The ADE should be installed using good electrical practice. Sea Tel recommends
referring to IEC 60092-352 for specific guidance in choosing cables and installing cables onboard a ship. Within these
guidelines, Sea Tel will provide some very general information regarding the electrical installation.
In general, all cable shall be protected from chaffing and secured to a cableway. Cable runs on open deck or down a
mast shall be in metal conduit suitable for marine use. The conduit shall be blown through with dry air prior to passing
cable to ensure all debris has been cleared out of the conduit and again after passing the cable to ensure no trapped
moisture exists. The ends of the conduit shall be sealed with cable glands (preferred), mastic or low VOC silicon
sealant after the cables have been passed through.
Cables passing through bulkheads or decks shall be routed through approved weather tight glands.
2.8.1. ADE/BDE Coaxial Cables
The first concern about the coaxial cables installed between the ADE & BDE is length. This length is used to
determine the loss of the various possible coax, Heliax or fiber-optic cables that might be used. You should
always provide the lowest loss cables to provide the strongest signal level into the satellite modem.
Signal cable shall be continuous from the connection within the ADE radome, through the structure of the
ship to the BDE. Splices, adapters or dummy connections will degrade the signal level and are discouraged.
Be careful of sharp bends that kink and damage the cable. Use a proper tubing bender for Heliax bends.
Penetrations in watertight bulkheads are very expensive, single cable, welded penetrations that must be
pressure tested.
Always use good quality connectors that are designed to fit properly on the cables you are using. Poor
quality connectors have higher loss, can allow noise into the cable , are easily damaged or fail prematurely.
In as much as is possible, don’t lay the coaxes on power cables. Try to have some separation from Inmarsat &
GPS cables that are also passing L-band frequencies or Radar cables that may inject pulse repetition noise –as
error bits - into your cables.
2.8.2. Antenna Power Cable
Be cautious of length of the run, for voltage loss issues, and assure that the gauge of the wires is adequate for
the current that is expected to be drawn (plus margin). Antenna power is not required to be from a UPS
(same one that supplies power to the below decks equipment), but it is recommended.
Power cable shall comply with the provisions of IEC 60092-350 and -351 in so far as practicable. Power
cable may be routed through the same conduit as the signal cable from the junction box to the base of the
ADE. Power cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the UPS (or closest circuit breaker) to the ADE connections within
the radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.
2.8.3. Air Conditioner Power Cable
If your system includes a marine air conditioner, run an AC power cable to it from a breaker, preferably from a
different phase of the electrical system than that which supplies power to the ADE & BDE. Be EXTREMELY
cautious of length of the run for voltage loss and gauge of the wires for the current that is expected to be
drawn.
Power cable shall comply with the provisions of IEC 60092-350 and -351 in so far as practicable. Power
cable may be routed through the same conduit as the signal cable from the junction box to the base of the
ADE. Power cables shall pass through separate radome penetrations from the signal cable.
The power cable shall be continuous from the closest circuit breaker to the ADE connections within the
radome. The power circuits shall be arranged so that ‘active,’ ‘common’ and ‘neutral’ (ground) legs are all
made or broken simultaneously. All circuit legs shall be carried in the same cable jacket.
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