Sea Tel ST88-21 C/Ku-Band TVRO 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 Antenna Systems
April 11, 2012 Document. No. 136464 Revision A
INSTALLATION AND OPERATION MANUAL
FOR SEA TEL MODEL
ST88-21 DUAL C/QUAD KU-BAND TVRO ANTENNA

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.
Revision History
REV ECO# Date Description By
A N/A April 11, 2012 Initial Production Release MDN

Copyright © Sea Tel, Inc 2011 Document Number 136150 rev A
Sea Tel, Inc.
4030 Nelson Ave., Concord
California, 94520, USA
T: [phone]
F: [phone]
Declaration of Potentially Hazardous Materials onboard for the Green
Passport Requirement
(Based on Annex 2 to the Industry Code of Practice on Ship Recycling, August 2001.*)
This inventory is part of the ship’s Green Passport and provides information with regard to materials known to be
potentially hazardous and utilized in the construction of the ship, its equipment and systems. It may be
supplemented, as appropriate, with technical information in respect of certain categories of potentially hazardous
materials listed in this document, particularly with regard to their proper removal and handling.
The Equipments Maker / Supplier have to declare if his equipment / equipments contain any of the hazardous
material listed below with concentration and duly signed and stamped.
Vessel Name/Hull Number/Shipyard:
Equipment Details: All Sea Tel manufactured antenna systems.
Supplier Details:
Sea Tel, Inc
4030 Nelson Ave
Concord, CA. 94520
Tel: [phone]
PART 1 – POTENTIALLY HAZARDOUS MATERIALS IN THE SHIP STRUCTURE AND EQUIPMENT
1A. ASBESTOS
Type of Asbestos Materials in
System/Equipment/Component
A
pproximate quantity/volume
N/A 0
1B. Paint with – Additives (Lead, Tin, Cadmium, Organotins (TBTs), Arsenic, Zinc, Chromium, Strontium, Other)
Type of Additives Materials containing
additives
Location (If Applicable) Approximate Quantit
y
N/A N/A N/A 0
1C.Plastic Materials
Type Components containing
plastic materials
Location (If Applicable) Approximate
quantity/volume
N/A N/A N/A 0

Copyright © Sea Tel, Inc 2011 Document Number 136150 rev A
1D. Materials containing PCBs, PCTs, PBBs at levels of 50mg/kg or more
Type PCBs/PCTs/PBBs Components containing
such materials
Location (If Applicable) Approximate
quantity/volume
N/A N/A N/A 0
1E. Gases sealed in the equipment or machinery of supplied system
Type Equipment/Component
containing such gases
Location (If
A
pplicable) Approximate
quantity/volume
Refrigerants (R12/R22) N/
A
N/
A
0
HALON N/
A
N/
A
0
CO² N/
A
N/
A
0
Acetylene N/
A
N/
A
0
Propane N/
A
N/
A
0
Butane N/
A
N/
A
0
Oxygen N/
A
N/
A
0
Other (Specify) N/
A
N/
A
0
1F. Chemicals in the equipment or machinery of supplied system
Type of chemicals Equipment/Component
containing such
chemicals
Location (If Applicable) Approximate
quantity/volume
Anti-seize Compounds N/
A
N/
A
0
Engine Additives N/
A
N/
A
0
Antifreeze Fluids N/
A
N/
A
0
Kerosene N/
A
N/
A
0
White Spirit N/
A
N/
A
0
Boiler/Water Treatment N/
A
N/
A
0
De-ioniser Regenerating N/
A
N/
A
0
Evaporator Dosing and N/
A
N/
A
0
Descaling Acids N/
A
N/
A
0
Paint/Rust Stabilisers N/
A
N/
A
0
Solvents/Thinners N/
A
N/
A
0
Chemical Refrigerants N/
A
N/
A
0
Battery Electrolyte N/
A
N/
A
0
Hotel Service Cleaners N/
A
N/
A
0
Other (Specify) N/
A
N/
A
0
1G. Other Substances inherent in the machinery, equipment or fittings of supplied system
Type Equipments/Components
contain such materials
Location (If
A
pplicable) Approximate
quantity/volume
Lubricating Oil N/
A
N/
A
0
Hydraulic Oil N/
A
N/
A
0
Lead Acid Batteries N/
A
N/
A
0
Alcohol N/
A
N/
A
0
Methylated Spirits N/
A
N/
A
0
Epoxy Resins N/
A
N/
A
0
Mercur
y
N/
A
N/
A
0
Radioactive Materials N/
A
N/
A
0
Other (Specify) N/
A
N/
A
0

Copyright © Sea Tel, Inc 2011 Document Number 136150 rev A
All of the plastics used on Sea Tel antenna systems are completely inert and pose no harm when in use or when
scrapped.
All of the lubricating oils used on Sea Tel antenna systems are completely inert and pose no harm when in use or
when scrapped.
All of the anti seize compounds used on Sea Tel antenna systems are completely inert and pose no harm when in
use or when scrapped.
We hereby declare that the above inventory of potentially hazardous material truly correspond to the equipment /
equipments supplied to ship.
Oct 06, 2011
John Phillips Date
VP Engineering
Sea Tel, Inc
4030 Nelson Ave.
Concord, CA. 94520
Tel: [phone]
Cobham plc is an international company engaged in the development, delivery and support of advanced aerospace and defence systems for land, sea
and air platforms. The company has five technology divisions and one in the service sector that collectively specialise in the provision of components,
sub-systems and services that keep people safe, improve communications and enhance the performance of aerospace and defence platforms.

Table of Contents
vii
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. PREPARING FOR THE INSTALLATION.......................................................................................................................................................... 3-2
3.3.1. Unpack Shipping Crates .........................................................................................................................................................3-2
3.3.2. Inspect / Inventory...................................................................................................................................................................3-2
3.3.3. Prepare ADE Mounting Location.......................................................................................................................................3-2
3.3.4. Preparing BDE Location .........................................................................................................................................................3-2
3.3.5. Installing The System Cables..............................................................................................................................................3-3
3.3.6. 126” Radome, Baseframe and Antenna Pedestal System Assembly ..............................................................3-3
3.3.7. Preparing the ADE for Lift.....................................................................................................................................................3-6
3.4. INSTALLING THE ADE .................................................................................................................................................................................. 3-7
3.4.1. Hoist..................................................................................................................................................................................................3-7
3.4.2. Install Antenna/Radome/Baseframe ...............................................................................................................................3-7
3.5. INSTALLING THE BELOW DECKS EQUIPMENT........................................................................................................................................... 3-7
3.5.1. General Cautions & Warnings .............................................................................................................................................3-7
3.5.2. Preparing BDE Location .........................................................................................................................................................3-7

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viii
3.5.3. Installing the Below Deck Equipment............................................................................................................................3-7
3.6. CONNECTING THE BELOW DECKS EQUIPMENT ........................................................................................................................................3-8
3.6.1. Connecting the ADE AC Power Cable............................................................................................................................3-8
3.6.2. Connecting the BDE AC Power Cables..........................................................................................................................3-8
3.6.3. Connecting the ADE IF Coaxes.........................................................................................................................................3-8
3.6.4. Antenna Control Unit Connections.................................................................................................................................3-8
3.6.5. 13Terminal Mounting Strip (TMS) Connections.......................................................................................................3-8
3.6.6. Other BDE connections .........................................................................................................................................................3-9
3.7. FINAL CHECKS..............................................................................................................................................................................................3-10
3.7.1. Visual/Electrical inspection............................................................................................................................................... 3-10
3.7.2. Electrical - Double check wiring connections......................................................................................................... 3-10
3.8. POWER-UP...................................................................................................................................................................................................3-10
3.9. CABLE TERMINATIONS...............................................................................................................................................................................3-10
3.9.1. At The Radome........................................................................................................................................................................3-10
3.9.2. ACU & TMS ................................................................................................................................................................................ 3-10
3.9.3. Other BDE Equipment .........................................................................................................................................................3-10
3.10. FINAL ASSEMBLY.........................................................................................................................................................................................3-10
3.10.1. Remove Stow Braces/Restraints..................................................................................................................................... 3-10
3.10.2. Verify all assembly and Wiring connections............................................................................................................ 3-10
3.11. POWER-UP THE ADE.................................................................................................................................................................................3-11
3.11.1. Initialization.............................................................................................................................................................................. 3-11
3.11.2. Home Flag Position...............................................................................................................................................................3-11
3.11.3. BDE ................................................................................................................................................................................................3-11
3.11.4. Balancing the Antenna........................................................................................................................................................3-11
3.11.5. Fine Balance and Monitoring Motor Drive Torque .............................................................................................. 3-12
3.12. SETUP ............................................................................................................................................................................................................3-13
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
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

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ix
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
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

Table of Contents
x
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. ST88-21 TECHNICAL SPECIFICATIONS.................................................................................................................................. 14-1
14.1. 8897 ANTENNA REFLECTOR ....................................................................................................................................................................14-1
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. 126” RADOME ASSEMBLY.........................................................................................................................................................................14-4
14.8. ENVIRONMENTAL CONDITIONS (ADE) ..................................................................................................................................................14-5
14.9. CABLES ..........................................................................................................................................................................................................14-5

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xi
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 ST88-21 DRAWINGS............................................................................................................................................................15-1
15.1. MODEL ST88-21 SPECIFIC DRAWINGS ................................................................................................................................................15-1
15.2. STXXX-21 GENERAL DRAWINGS..............................................................................................................................................................15-1

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ST88-21 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 inport 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 (dependant 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

Introduction ST88-21 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.

ST88-21 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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ST88-21 C/Ku-Band TVRO Site Survey
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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.

Site Survey ST88-21 C/Ku-Band TVRO
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2.3. Mounting Foundation
2.3.1.
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.
Mounting on Deck or Deckhouse
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.
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.
ADE Mounting Considerations
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.
The following should be taken into account when choosing the height of a mounting support stand:
Sizing of the support pedestal
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.

ST88-21 C/Ku-Band TVRO Site Survey
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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.

Site Survey ST88-21 C/Ku-Band TVRO
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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 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
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 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
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.