Sea Tel 9797A-27 User manual

Sea Tel, Inc.
4030 Nelson Avenue
Concord, CA 94520
Tel: [phone]
Fax: [phone]
Email: [email protected]
Web: www.seatel.com Look to the Leader. Look to Sea Tel.
Sea Tel Europe
Unit 1, Orion Industrial Centre
Wide Lane, Swaythling
Southampton, UK S0 18 2HJ
Tel: [phone]
Fax: [phone]
Email: [email protected]
Web: www.seatel.com
November 4, 2004 Document. No. 123273
Revision A
INSTALLATION AND OPERATION MANUAL
FOR SEA TEL MODEL
9797A-27 C-BAND TX/RX ANTENNAS
WARNING: RF RADIATION HAZARD
This stabilized antenna system is designed to be used with transmit/receive
equipment manufactured by others. Refer to the documentation supplied by the
manufacturer which will describe potential hazards, including exposure to RF
radiation, associated with the improper use of the transmit/receive equipment.
Note that the transmit/receive equipment will operate independently of the
stabilized antenna system. Prior to work on the stabilized antenna system, the
power to the transmit/receive system must be locked out and tagged.
When the transmit/receive system is in operation, no one should be allowed
anywhere within the radiated beam being emitted from the reflector.
The ultimate responsibility for safety rests with the facility operator and the
individuals who work on the system.

ii
Sea Tel Marine Stabilized Antenna systems are manufactured in the United
States of America.
Sea Tel is an ISO 9001 registered company. Registration Number M2314 which
was first issued on November 09, 1998.
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
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 the consent of Sea Tel, Inc. The
information in this document is subject to change without notice.
Copyright © 2004 Sea Tel, Inc.

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iv
Revision History
REV ECO# Date Description By
A N/A November 4, 2004 Initial Release MDN

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. GENERAL SCOPE OF THIS MANUAL.................................................................................................... 1-2
1.5. QUICK OVERVIEW OF CONTENTS...................................................................................................... 1-2
2. OPERATION........................................................................................................................................ 2-1
2.1. SYSTEM POWER-UP ........................................................................................................................ 2-1
2.2. ANTENNA INITIALIZATION.................................................................................................................. 2-1
2.3. ANTENNA STABILIZATION ................................................................................................................. 2-2
2.4. TRACKING OPERATION .................................................................................................................... 2-2
2.5. ANTENNA POLARIZATION OPERATION............................................................................................... 2-2
2.6. RF EQUIPMENT...............................................................................................................................2-2
2.7. STABILIZED PEDESTAL ASSEMBLY OPERATION ................................................................................. 2-2
2.8. RADOME ASSEMBLY OPERATION...................................................................................................... 2-2
3. BASIC SYSTEM INFORMATION ....................................................................................................... 3-1
3.1. SATELLITE BASICS........................................................................................................................... 3-1
3.1.1. C-Band Reveive Frequency (3.7-4.2GHz) ....................................................................... 3-1
3.1.2. Ku-Band ReceiveFrequency (10.95-12.75GHz) .............................................................. 3-1
3.1.3. Blockage........................................................................................................................... 3-1
3.1.4. Rain Fade......................................................................................................................... 3-2
3.1.5. Signal level ....................................................................................................................... 3-2
3.1.6. Satellite Footprints............................................................................................................ 3-2
3.1.7. Linear Satellite polarization .............................................................................................. 3-2
3.1.8. Satellite Circular Polarization ...........................................................................................3-2
3.2. ANTENNA BASICS ............................................................................................................................ 3-3
3.2.1. Unlimited Azimuth ............................................................................................................ 3-3
3.2.2. Elevation........................................................................................................................... 3-3
3.2.3. Feed Assembly ................................................................................................................ 3-3
3.2.4. Antenna polarization......................................................................................................... 3-3
3.2.5. Stabilization ...................................................................................................................... 3-3
3.2.6. Search Pattern ................................................................................................................. 3-4
3.2.7. Tracking Receiver – Single Channel Per Carrier Receiver .............................................. 3-4
3.2.8. Tracking ........................................................................................................................... 3-4
3.3. COMPONENTS OF THE SYSTEM CONFIGURATION............................................................................... 3-4
3.3.1. Antenna ADE Assembly ................................................................................................... 3-6
3.3.2. Antenna Control Unit ........................................................................................................ 3-6
3.3.3. Power Supply ................................................................................................................... 3-7
4. INSTALLATION................................................................................................................................... 4-1
4.1. GENERAL CAUTIONS & WARNINGS .................................................................................................. 4-1
4.2. SITE SURVEY .................................................................................................................................. 4-2
4.3. PREPARING FOR THE INSTALLATION................................................................................................. 4-2
4.3.1. Unpack Shipping Crates .................................................................................................. 4-2
4.3.2. Inspect / Inventory............................................................................................................ 4-3
4.3.3. Prepare ADE Mounting Location...................................................................................... 4-3

Table of Contents
vi
4.3.4. Prepare GPS Mounting Location......................................................................................4-3
4.3.5. Preparing BDE Location...................................................................................................4-3
4.3.6. Installing The System Cables...........................................................................................4-3
4.4. ASSEMBLING THE ADE ....................................................................................................................4-3
4.4.1. 144” Radome, Baseframe and Antenna Pedestal System Assembly ..............................4-3
4.4.2. Preparing the ADE for Lift ................................................................................................4-5
4.4.3. Assembling The GPS Engine...........................................................................................4-5
4.5. INSTALLING THE ADE...................................................................................................................... 4-5
4.5.1. Hoist .................................................................................................................................4-5
4.5.2. Install Antenna/Radome/Baseframe.................................................................................4-5
4.5.3. Install GPS Engine ........................................................................................................... 4-5
4.5.4. Cooling Unit Assembly - TX SYSTEMS ONLY ..............................................................4-5
4.6. INSTALL BDE EQUIPMENT ...............................................................................................................4-6
4.6.1. ACU & TMS......................................................................................................................4-6
4.6.2. Other BDE Equipment......................................................................................................4-6
4.7. CABLE TERMINATIONS .....................................................................................................................4-6
4.7.1. At The Radome ................................................................................................................4-6
4.7.2. GPS..................................................................................................................................4-6
4.7.3. ACU & TMS......................................................................................................................4-6
4.7.4. Other BDE Equipment......................................................................................................4-6
4.8. FINAL ASSEMBLY.............................................................................................................................4-6
4.8.1. Mount RF Equipment (TXRX Only) .................................................................................. 4-6
4.8.2. Remove Stow Braces/Restraints ..................................................................................... 4-6
4.8.3. Verify all assembly and Wiring connections..................................................................... 4-7
4.8.4. Balance Antenna Pedestal ............................................................................................... 4-7
4.9. POWER-UP THE ADE...................................................................................................................... 4-7
4.9.1. Initialization.......................................................................................................................4-7
4.9.2. Home Flag Position ..........................................................................................................4-7
4.9.3. BDE ..................................................................................................................................4-7
4.10. SETUP ......................................................................................................................................... 4-7
5. SETUP .................................................................................................................................................5-1
5.1. OPERATOR SETTINGS......................................................................................................................5-1
5.2. OPTIMIZING TARGETING...................................................................................................................5-1
5.3. OPTIMIZING AUTO-POLARIZATION .................................................................................................... 5-1
5.4. CALIBRATING RELATIVE ANTENNA POSITION (HOME FLAG OFFSET) ..................................................5-2
5.4.1. To Calculate HFO:............................................................................................................5-2
5.4.2. To Enter the HFO value: ..................................................................................................5-3
5.5. RADIATION HAZARD AND BLOCKAGE MAPPING..................................................................................5-4
5.6. TX POLARITY SETUP .......................................................................................................................5-5
5.7. ACU FACTORY DEFAULT PARAMETER SETTINGS – SERIES 97A ANTENNAS ...................................... 5-6
6. FUNCTIONAL TESTING.....................................................................................................................6-1
6.1. ACU / ANTENNA SYSTEM CHECK.....................................................................................................6-1
6.2. LATITUDE/LONGITUDE AUTO-UPDATE CHECK.................................................................................... 6-1
6.3. HEADING FOLLOWING......................................................................................................................6-1
6.4. AZIMUTH & ELEVATION DRIVE .......................................................................................................... 6-2

Table of Contents
vii
6.5. TEST TRACKING .............................................................................................................................. 6-2
7. MAINTENANCE AND TROUBLESHOOTING.................................................................................... 7-1
7.1. WARRANTY INFORMATION................................................................................................................ 7-1
7.2. RECOMMENDED PREVENTIVE MAINTENANCE .................................................................................... 7-2
7.2.1. Check ACU Parameters................................................................................................... 7-2
7.2.2. Latitude/Longitude Auto-Update check ............................................................................7-2
7.2.3. Heading Following............................................................................................................ 7-2
7.2.4. Azimuth & Elevation Drive................................................................................................ 7-2
7.2.5. Test Tracking ................................................................................................................... 7-2
7.2.6. Visual Inspection - Radome & Pedestal.........................................................................7-2
7.2.7. Mechanical Checks .......................................................................................................... 7-2
7.2.8. Check Balance ................................................................................................................. 7-3
7.2.9. Observe Antenna Initialization.......................................................................................... 7-3
7.3. TROUBLESHOOTING......................................................................................................................... 7-3
7.3.1. Theory Of Operation ........................................................................................................ 7-3
7.3.2. Antenna Initialization (Series 97A & Series 00 )............................................................... 7-4
7.3.3. Antenna Position Error Monitoring ................................................................................... 7-4
7.3.4. Reference Sensor Testing ...............................................................................................7-4
7.3.5. Open Loop Motor Sensor Test.........................................................................................7-5
7.3.6. Open Loop Motor Test .....................................................................................................7-5
7.3.7. To Disable/Enable DishScan............................................................................................ 7-5
7.3.8. Satellite Reference Mode ................................................................................................. 7-5
7.3.9. To Read/Decode an ACU Error Code 0008 (Pedestal Error): ......................................... 7-6
7.4. MAINTENANCE................................................................................................................................. 7-7
7.4.1. Balancing the Antenna .....................................................................................................7-7
7.4.2. 24 VDC Polang Alignment................................................................................................ 7-7
7.4.3. To Adjust Tilt: ................................................................................................................... 7-8
7.4.4. To Reset/Reinitialize the Antenna: ................................................................................... 7-8
7.5. PEDESTAL CONTROL UNIT CONFIGURATION (XX97A & XX00) ............................................................ 7-8
7.5.1. MODEL CONFIGURATION NUMBERS .......................................................................... 7-9
7.6. ANTENNA STOWING PROCEDURE ..................................................................................................... 7-9
7.7. ALIGNING THE DROP-IN FEED, OF THE ANTENNA.............................................................................. 7-11
8. 9797A-27 TECHNICAL SPECIFICATIONS ........................................................................................ 8-1
8.1. 9797 ANTENNA REFLECTOR ............................................................................................................ 8-1
8.2. FEED ASSEMBLIES .......................................................................................................................... 8-1
8.2.1. C-Band TXRX Feed Assembly......................................................................................... 8-1
8.3. 9797-27 RF EQUIPMENT................................................................................................................. 8-1
8.4. 9797A STABILIZED ANTENNA PEDESTAL ASSEMBLY ......................................................................... 8-2
8.5. PEDESTAL CONTROL UNIT (PCU) .................................................................................................... 8-2
8.6. UNLIMITED AZIMUTH MODEMS(4 CHANNEL)...................................................................................... 8-2
8.7. 144” RADOME ASSEMBLY ................................................................................................................ 8-3
8.8. ENVIRONMENTAL CONDITIONS (ADE)............................................................................................... 8-3
8.9. CABLES ADE TO BDE..................................................................................................................... 8-4
8.9.1. TXRX IF Signal Cables ....................................................................................................8-4
8.9.2. Antenna Control Cable .....................................................................................................8-4

Table of Contents
viii
8.9.3. GPS Interface Cable ........................................................................................................8-4
8.9.4. AC Power Cable (Pedestal & Rf Equipment) ................................................................... 8-4
8.9.5. AC Power Cable (Marine Air Conditioner)........................................................................ 8-4
9. DRAWINGS .........................................................................................................................................9-1
9.1. SERIES 97A TXRX SYSTEMS - PART NUMBER QUICK REFERENCE................................................... 9-1
9.2. 9797A-27 MODEL SPECIFIC DRAWINGS........................................................................................... 9-2
9.3. SERIES 97 GENERAL DRAWINGS .....................................................................................................9-2

9797A-27 C-Band TXRX Introduction
1-1
1. Introduction
WARNING: RF Radiation Hazard - This stabilized antenna system is designed to be
used with transmit/receive equipment manufactured by others. Refer to the
documentation supplied by the manufacturer which will describe potential hazards,
including exposure to RF radiation, associated with the improper use of the
transmit/receive equipment. Note that the transmit/receive equipment will operate
independently of the stabilized antenna system.
The ultimate responsibility for safety rests with the facility operator and the
individuals who work on the system.
1.1. General Description of system
Your Series 97 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 Transmit-Receive (TXRX) system provides you with two-way satellite voice/data
communications while underway on an ocean-going vessel. This can be used to provide a wide variety of
telephone, fax and data applications. Your Series 97 Antenna system can transmit to and receive from any
desired satellite which has adequate signal coverage in your current geographic area. Your Series 97
antenna may be fitted with appropriate Transmit & Receive RF Equipment and appropriate Feed to allow you
to operate in linear or circular polarization mode at C-Band frequencies. This input will be distributed to your
satellite modem and then to all of your other below decks equipment.
1.3. System Components
The Series 97 TXRX system consists of two major groups of equipment; an above-decks group and a below-
decks group. Each group is comprised of 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.
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 C-Band Radio Package
5 C-Band High Power Amplifier
6 Radome Assembly
B. Below-Decks Equipment Group

Introduction 9797A-27 C-Band TXRX
1-2
7 Antenna Control Unit
8 Splitter with desired number of outputs (one output to the ACU and one output to the Satellite
Modem are required).
9 Satellite Modem and other below decks equipment required for the desired communications
purposes.
10 Spectrum Analyzer (Optional)
11 Control, RF and Video cables
Figure 1-1 Series 97 TXRX Simplified Block Diagram
1.4. General scope of this manual
This manual describes the Sea Tel Series 97 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.
1.5. 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

9797A-27 C-Band TXRX Operation
2-1
2. Operation
WARNING: RF Radiation Hazard - This stabilized antenna system is designed to be
used with transmit/receive equipment manufactured by others. Refer to the
documentation supplied by the manufacturer which will describe potential hazards,
including exposure to RF radiation, associated with the improper use of the
transmit/receive equipment. Note that the transmit/receive equipment will operate
independently of the stabilized antenna system.
The ultimate responsibility for safety rests with the facility operator and the
individuals who work on the system.
WARNING: RF Radiation Hazard - When the transmit/receive system is in operation, no
one should be allowed anywhere within the radiated beam being emitted from the reflector.
The ultimate responsibility for safety rests with the facility operator and the
individuals who work on the system.
2.1. System Power-up
Turn the Power switch on the louvered panel of the antenna pedestal ON. This will energize the antenna
pedestal and the associated RF equipment.
Turn the Power switch on rear panel of the Antenna Control Unit (ACU) ON.
2.2. Antenna Initialization
A functional operation check can be made on the antenna stabilization system by observing its behavior
during the 4 phases of initialization.
Turn the pedestal power supply ON. The PCU will initialize the stabilized portion of the mass to be level with
the horizon and at a prescribed Azimuth and Elevation angles. The antenna will go through the specific
sequence of steps (listed below) to initialize the antenna. These phases initialize the level cage, elevation,
cross-level and azimuth to predetermined starting positions.
Initialization is completed in the following phases, each phase must complete properly for the antenna to
operate properly (post-initialization).
1 Level Cage is driven CCW, issuing extra steps to assure that the cage is all the way to the
mechanical stop. Then the Level cage will be driven exactly 45.0 degrees CW.
2 Elevation axis activates - Input from the LV axis of the tilt sensor is used to drive the Elevation of
the equipment frame to bring the tilt sensor LV axis to level (this results in the dish being at an
elevation angle of 45.0 degrees).
3 Cross-Level axis activates - Input from the CL axis of the tilt sensor is used to drive Cross-Level
of the equipment frame to bring the cross-level axis of the tilt sensor to level (this results in the
tilt of the Cross-Level Beam being level).
4 Azimuth axis activates - Antenna drives in azimuth until the “Home Flag” signal is produced.
This signal is produced by a Home Switch hitting a cam or by a Hall Effect sensor in close

Operation 9797A-27 C-Band TXRX
2-2
proximity to a Magnet.
This completes the phases of initialization. At this time the antenna elevation should 45.0 degrees and
Relative azimuth should be at be at home flag (home switch engaged on the home flag cam).
If any of theses steps fail, or the Antenna Control Unit reports model number as "xx97" re-configure the PCU
as described in section the Setup section of this manual. If initialization still fails, refer to the troubleshooting
section of this manual.
2.3. Antenna Stabilization
After initialization has completed, real-time stabilization of the antenna is an automatic function of the PCU.
2.4. Tracking Operation
Tracking optimizes the pointing of the antenna, in very fine step increments, to maximize the level of the
satellite signal being received. This is done using a variation of Conical Scanning called DishScan. Tracking
is controlled by the ACU. You can toggle Tracking ON/OFF from the ACU.
You cannot control tracking from the pedestal itself. Refer to the ACU manual for more Tracking information.
2.5. Antenna Polarization Operation
Linear feeds are equipped with a polarization motor and potentiometer feedback and are controlled from the
Antenna Control Unit. Circular feeds do NOT require polarization adjustment.
Auto-Polarization mode is the default polarization mode of operation from the ACU. Polarization may be
operated manually from the ACU. Refer to the Antenna Control Unit manual for more operation information.
2.6. RF Equipment
The RF Equipment is not operated or controlled by the antenna pedestal or Antenna Control Unit. Refer to
the vendor supplied manuals for the RF Equipment provided with your system.
2.7. Stabilized Pedestal Assembly Operation
Operation of the stabilized antenna Pedestal Control Unit (PCU) is accomplished remotely by the Antenna
Control Unit (ACU). Refer to the Operation section of the Antenna Control Unit manual for more specific
operation details. There are no other operating instructions applicable to the pedestal assembly by itself.
2.8. Radome Assembly Operation
When operating the system it is necessary that the radome access hatch (and/or side door) be closed and
secured in place at all times. This prevents rain, salt water and wind from entering the radome. Water and
excessive condensation promote rust & corrosion of the antenna pedestal. Wind gusts will disturb the
antenna pointing.
There are no other operating instructions applicable to the radome assembly by itself.

9797A-27 C-Band TXRX Basic System Information
3-1
3. Basic System Information
This section provides you with some additional information about the satellites you will be using, basics of your
Series 97 antenna system and some of the other equipment within your system configuration.
3.1. Satellite Basics
The satellites are in orbit at an altitude of 22,754 miles and are positioned directly above the equator. Their
orbital velocity matches the Earth’s rotational speed, therefore, each appears to remain at a fixed position in
the sky (as viewed from your location).
Your antenna can be used with any of the satellites in this orbit that have a strong enough receive signal
level. Your antenna is capable of being fitted with a Linear or Circular feed assembly. The feed may be
designed to operate at C-Band frequencies, Ku-Band frequencies or be capable of operation in both bands.
With the correct feed assembly you will be able to receive the linear or circular signal at the specific frequency
range of the desired satellite.
3.1.1. C-Band Reveive Frequency (3.7-4.2GHz)
At these frequencies the signal from the satellite travels only in a straight line and is affected by weather
changes in the atmosphere. There are several conditions that can cause a temporary loss of satellite
signal, even within an area where the signal level is known to be adequate. The most common of these
normal temporary losses are blockage and rain fade. They will interrupt services only as long as the
cause of the loss persists.
3.1.2. Ku-Band ReceiveFrequency (10.95-12.75GHz)
At these frequencies the signal from the satellite travels only in a straight line and is affected by weather
changes in the atmosphere. There are several conditions that can cause a temporary loss of satellite
signal, even within an area where the signal level is known to be adequate. The most common of these
normal temporary losses are blockage and rain fade. They will interrupt services only as long as the
cause of the loss persists.
3.1.3. Blockage
Blockage is loss due to an object in the path of the signal from the satellite to the dish. If an object that is
large and dense is positioned in the path of the signal from the satellite, it will prevent sufficient signal from
arriving at the dish. The signal can not bend around, or penetrate through, these objects and the
reception will be degraded or completely interrupted. The dish is actively driven to remain pointed at the
satellite (toward the equator) so, as the ship turns a mast or raised structure of your ship may become
positioned between the satellite and the dish. Blockage may also be caused a anything standing near the
radome, tall mountains, buildings, bridges, cranes or other larger ships near your ship. Moving or rotating
the ship to position the antenna where it has an unobstructed view to the desired satellite will restore the
antennas’ ability to receive the satellite signal.

Basic System Information 9797A-27 C-Band TXRX
3-2
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3.1.4. Rain Fade
Atmospheric conditions that may cause sufficient loss of signal level include rain, snow, heavy fog and
some solar activities (sun spot and flare activity). The most common of these is referred to as “rain fade”.
Rain drops in the atmosphere reduce the signal from the satellite. The heavier the rain the higher the
amount of signal loss. When the amount of loss is high enough, the antenna will not be able to stay
locked onto the satellite signal. When the amount of rain has decreased sufficiently, the antenna will re-
acquire the satellite signal. In a strong signal area, rain fall of about four inches per hour will cause
complete loss of signal. In weaker signal areas the effects would be more pronounced.
3.1.5. Signal level
The level of the receive signal is dependant upon how powerful the transmission is and how wide the
signal beam is coverage area is. Focusing the signal into a narrower beam concentrates its energy over a
smaller geographic area, thereby increasing the signal level throughout that area of coverage. This
makes it possible for you to use a smaller antenna size to receive that satellite signal. The antenna
system must be geographically located in an area where the signal level from the satellite meets (or
exceeds) the minimum satellite signal level required for your size of antenna (refer to the Specifications
section of this manual) to provide suitable reception. This limits the number of satellites that can be used
and the geographic areas where the ship can travel where the signal level is expected to be strong
enough to continue providing uninterrupted reception. When travelling outside this minimum signal
coverage area, it is normal for the system to experience an interruption in its ability to provide the desired
satellite services until entering (or re-entering) an area of adequate signal level.
3.1.6. Satellite Footprints
The focused beam(s) from the satellites are normally aimed at the major land masses where there are
large population centers. Footprint charts graphically display the signal level expected to be received in
different geographic locations within the area of coverage. The signal will always be strongest in the
center of the coverage area and weaker out toward the outer edges of the pattern. The Drawing section
of this manual contains footprint charts of satellites that are expected to provide adequate signal level for
your size antenna. The coverage areas are intended to be a guide to reception, however, the actual
coverage area and signal level and vary. Also the signal strength is affected by weather.
3.1.7. Linear Satellite polarization
Satellites may transmit their signals in one
of two different polarization modes, linear
or circular. The feed installed on your
antenna is designed to operate with
horizontal and vertical linear polarized
satellite transmissions, thereby requiring
periodic adjustment of “polarization”.
Polarization adjustment is required to
optimize the alignment of the LNB to match
the angle of the signal from the satellite.
When you are on the same longitude as
the satellite, its’ horizontal and vertical signals will be purely aligned to your horizon. When the satellite is
east or west of your longitude, the satellite signals will appear to be rotated clockwise or counter-clockwise
from pure horizontal and vertical. Both horizontal and vertical signals from a satellite will appear to be
rotated the same amount and are always perpendicular to each other. The amount of rotation is
dependent on how far east or west the satellite is from you and how close you are to the Equator.
3.1.8. Satellite Circular Polarization
When the satellite you are using is transmitting circular polarized satellite transmissions, you will not need
to adjust the “polarization” of your antenna.

9797A-27 C-Band TXRX Basic System Information
3-3
3.2. Antenna Basics
The following information is provided to explain some of the basic functions of the antenna:
3.2.1. Unlimited Azimuth
Azimuth rotation of the antenna is unlimited (no mechanical stops). Azimuth drive, provided by the
azimuth motor, is required during stabilization, searching and tracking operations of the antenna. When
the boat turns, azimuth is driven in the opposite direction to remain pointed at the satellite. The actual
azimuth pointing angle to the satellite is determined by your latitude & longitude and the longitude of the
satellite. It is important to know that the antenna should be pointed (generally) toward the equator.
The azimuth angle to the satellite would be 180 degrees true (relative to true north) if the satellite is at the
same longitude that you are on. If the satellite is east, or west, of your longitude the azimuth will be less
than, or greater than 180 degrees respectively.
When checking for blockage you can visually look over the antenna radome toward the equator to see if
any objects are in that sighted area. If you are not able to find any satellites it may also be useful to
remove the radome top to see if the dish is aimed the correct direction (towards the equator).
3.2.2. Elevation
In normal operation the elevation of the antenna will be between 00.0 (horizon) and 90.0 (zenith). The
antenna can physically be rotated in elevation below horizon and beyond zenith to allow for ship motion.
Elevation drive, provided by the elevation motor, is required during stabilization, searching and tracking
operations of the antenna. The actual elevation pointing angle to the satellite is determined by your
latitude & longitude and the longitude of the satellite. In general terms the elevation angle will be low when
you are at a high latitudes and will increase as you get closer to the equator.
Refer to figure 3-1. Additionally, from any given latitude, the elevation will be highest when the satellite is
at the same longitude that you are on. If the satellite is east, or west, of your longitude the elevation angle
will be lower.
3.2.3. Feed Assembly
The scalar section of the feed is fitted with a polarization motor and a potentiometer for position feedback
required for linear signal operation. The feed may be fitted for Linear or Circular reception. The
appropriate LNA, LNB or LNC must be installed on the Linear or Circular section of the feed to receive the
frequencies of the desired satellite.
When a Linear feed is installed, the ACU automatically adjusts the feed by remotely controlling the 24 volt
DC motor, using the potentiometer feedback for Linear polarization position (Auto-Polarization mode).
When a Circular feed is installed, no polarization adjustment is required because the circular feed receives
the signal properly regardless of its polarization position.
The feed may be dual band (C-Band and Ku-Band) allowing you to use either band. The Tracking - Band
Selection remotely controls coax switches mounted on the antenna pedestal to select which LNB outputs
are routed through the antenna pedestal to the Below Decks Equipment.
3.2.4. Antenna polarization
You have a linear polarization feed installed, the system should have been adjusted properly and set-up
to operate in Auto-Polarization mode. The ACU will then automatically adjust the polarization of the feed,
as necessary, while the ship travels in Latitude and Longitude.
3.2.5. Stabilization

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The Series 97 antennas are stabilized in all three axes of motion. Stabilization is the process of de-
coupling the ships’ motion from the antenna. Simply put, this allows the antenna to remain pointed at the
satellite while the boat turns, rolls or pitches under it. To accomplish this, the Pedestal Control Unit (PCU)
on the antenna pedestal assembly senses the motion and applies drive to the appropriate motor(s) in
opposition to the sensed motion. Azimuth (AZ), Elevation (EL) and Cross-Level (left-right tilt) are actively
stabilized automatically by the PCU as part of its normal operation.
3.2.6. Search Pattern
Whenever the desired satellite signal is lost (such as when the antenna is blocked) the Antenna Control
Unit will automatically initiated a Search to re-acquire the desired signal.
Search is conducted in a two-axis pattern consisting of alternate movements in azimuth and elevation.
The size and direction of the movements are increased and reversed every other time resulting in an
expanding square pattern.
When the antenna is able to re-acquire the desired signal the ACU will automatically stop searching and
begin Tracking the signal to optimize the pointing of the antenna to get the highest signal level from the
satellite.
3.2.7. Tracking Receiver – Single Channel Per Carrier Receiver
The SCPC Narrow Band Receiver located in the Antenna Control Unit (ACU) is used to acquire, identify
and track a narrow band carrier, or beacon signal, or the desired satellite. When properly setup, the
settings for the satellite are saved to expedite future acquisition of the desired satellite. The system must
have adequate satellite signal level to stop searching (and begin tracking the acquired satellite).
3.2.8. Tracking
Your Antenna Control Unit actively optimizes the pointing of the dish for maximum signal reception. This
process is called tracking and is accomplished by continuously making small movements of the dish
while monitoring the level of the received signal. Evaluation of this information is used to continuously
make minor pointing corrections to keep the signal level “peaked” as part of normal operation.
3.3. Components of the System Configuration

9797A-27 C-Band TXRX Basic System Information
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Figure 3-2 Series 97 TVRO Simplified Block Diagram
The following text provides a basic functional overview of the system components and component
interconnection as referred to in the simplified block diagram for your Series 97 antenna. Also, refer to the
appropriate page of the System Block Diagram which depicts your system configuration.
70MHz RXIF
70MHz RXIF
70MHz TXIF
70MHz TXIF
70MHz RXIF
Radio M&C
Pedestal M&C
110/22 0 VAC to Pede stal
& RF Equipment
220 VAC to OPTIONAL
Marine Air Conditioner
Spectrum Analyzer “A”
9797
TXRX
Antenna
J11 J1 RF
Input
PCDAC
Cable
(116670)
Ships Gyro
Compass
J13 J3
Satellite Modem
Multiplexer
Phone,
Fax and
Data
Inputs
Synchro
OR
SBS
110/220
VAC
110/220
VAC
110/220
VAC
110/220
VAC
Above Decks
Above DecksAbove Decks
Above Decks
Below Decks
Below DecksBelow Decks
Below Decks
110/22 0
VAC
Your Computer w/
PCDAC Software
DAC-97
Antenna
Control
Unit
GPS

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3.3.1. Antenna ADE Assembly
The Above Decks Equipment consists of an Antenna
Pedestal inside a Radome assembly. The pedestal
consists of a satellite antenna dish & feed with a linear,
or a circular Low Noise Block converter (LNB) with
polarization motor mounted on a stabilized antenna
pedestal. The radome provides an environmental
enclosure for the antenna pedestal assembly inside it.
This keeps wind, water condensation and salt-water
spray off the antenna pedestal assembly. This prevents
damage and corrosion that would shorten the expected
life span of the equipment.
Two coaxial cables are connected from the antenna
radome assembly to the below decks equipment. One
of these cables includes the Antenna Control signaling
and IF, the other cable carries the other IF signal.
These cables ultimately provide the input/output signals
into/out of the satellite modem.
3.3.2. Antenna Control Unit
The Antenna Control Unit allows the operator to control and monitor the antenna pedestal with dedicated
function buttons, LED’s and a 2 line display. The ACU and its Terminal Mounting Strip are normally
mounted in a standard 19” equipment rack. The ACU should be mounted in the front of the equipment
rack where it is easily accessible. The Terminal Mounting Strip is normally mounted on the rear of the
equipment rack. It is recommended that the antenna control panel be mounted near one of the Satellite
Receiver locations where you can see the television screen while you are controlling the antenna.
The Antenna Control Unit is connected to the antenna, ships Gyro Compass and to the GPS Engine
(when included).
Figure 3-4 DAC Antenna Control Unit
The Antenna Control Unit (ACU) communicates via an RS-422 serial data link with the Pedestal Control
Unit (PCU) located on the antenna. This control signal is sent up the Antenna Control cable along with the
DC voltage for the antenna power. The Pedestal Control Unit stabilizes the antenna against the ship's roll,
pitch, and turning motions. The ACU is the operator interface to the PCU and provides the user with a
choice of positioning commands to point the antenna, search commands to find the satellite signal and
tracking functions to maintain optimum pointing.
Figure 3-3 Series 97 TXRX Above Decks Equipment

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3.3.3. Power Supply
AC Voltage - An appropriate source of AC Voltage will also be required for the ACU, satellite modem
and other below decks equipment. Refer to the manuals for these devices for voltage and power
consumption of each.

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