HiSeasNet Training Seatel Stabilized Antennas Series 9797, 4996, 4006, & 6006

HiSeasNet Training

Seatel Stabilized Antennas

Series 9797, 4996, 4006, & 6006

*HiSeasNet OutlineWelcome & IntroductionBasic Satellite InformationTypes of Satellite Orbits and Orbital SpacingFrequency Bands and AdvantagesPolarizationFootprint BasicsSystem Block DiagramsBasic Antenna Components Above Decks Equipment (ADE)Basic Antenna Components Below Decks equipment (BDE)Basic System FunctionsAntenna Pointing, Targeting, and TrackingStabilizationTrackingSearchingInstallationSystem SetupOperationFunctional TestingTroubleshooting and RepairLab Exercises

Network Overview

*Welcome & IntroductionWhy youre here

-Gain an understanding of the installation, operation, maintenance, and troubleshooting of the Seatel stabilized antenna system.

What are the key points

Pointing/- Accurately driving the antenna to precise Azimuth Targeting and Elevation angles in three dimensional free space to be consistent with where the satellite signal is emanating from

Stabilization - Maintaining the Azimuth and Elevation pointing angles while the ship is rolling, pitching and turning

Tracking - Use of the received satellite signal level to continuously evaluate and optimize the pointing angles of the antenna for maximum signal level reception.

*Welcome & Introduction Definitions of Terms

Seatel Antenna System

Relative (REL) - Mechanical azimuth rotational position of the antenna relative to the Bow of the ship. When the antenna is pointed inline with the Bow of the ship the REL display should be 360.0/000.0. Range of display is 000.0-359.9.

Azimuth (AZ) - True Azimuth (requires Ships Gyro Compass input). The Azimuth pointing angle of the antenna relative to True North (North Pole of the Earth). When the antenna is pointed True North display will be 000.0, East at 090.0, South at 180.0 and West at 270.0. Range of display is 000.0-359.9, Up direction is CW rotation of the antenna.

Elevation (EL) - Elevation pointing angle of the antenna between Horizon (000.0) and Zenith (090.0).

Level (LV) - Pedestal Fore/Aft upright position relative to the Horizon. Level Sensor is a gravity reference to bring the Level Cage (fore/aft) aspect to level". This input is used to stabilize Elevation.

Cross-Level (CL) -Pedestal Left/Right tilt position relative to the Horizon. Level Sensor is a gravity reference to bring the Level Cage (Left/Right) aspect to level. This input is used to stabilize The Left/Right Tilt of the antenna.

*Welcome & Introduction

Definition of Terms continued

Ship Movement Effects

Roll - Tilting motion of the ship from side (Port) to side (Starboard).

Pitch - Tilting motion of the ship from Bow to Aft.

Yaw - Serpentine oscillation of the ship along a desired heading (steering badly)

Center of Gravity (C/G) - Center of gravity of the mass of the antenna. Azimuth, Elevation and Cross Level are aligned at the factory to be coincident within 0.003 inch.

Static Balance - Proper 3-dimensional balance of the antenna is critical to stabilization. When properly balanced the un-energized antenna can be pointed to any AZ/EL pointing position and it will remain pointed there when released.

*Welcome & Introduction

Definition of Terms continued

Supporting Equipment

SSPA - Solid State Power Amplifier. Part of the RF equipment mounted on the antenna. Provides the transmit power for the outbound signal

G/T - Gain over Temperature (degrees Kelvin) a measure of the efficiency of the antenna reflector to provide gain (amplify) the desired signals

LNA - Low Noise Amplifier. This unit amplifies the C-Band frequencies with no frequency down conversion

LNB - Low Noise Block Downconverter. This unit amplifies the Ku-Band frequenciesand then downconverts them to L-Band frequencies.

L-Band - The frequency range of 950 MHz to 1450 MHz. The 4006 & 6006 antenna systems employ the frequency band along with the Comtech modems

EIRP - Effective Radiated Isotropic Power A measurement of power relative to an isotropic source

*Welcome and IntroductionDefinition of Terms continued

DAC Digital Antenna Controller / Antenna Control Unit - Seatel supplied antenna controller

ACU Antenna Control Unit, ACU = DAC

SCPC Single Channel Per Carrier - The transmission of a single data signal at a given frequency and bandwidth. The Comtech modems used in the HiSeasNet network use this type of transmission.

Satellite - Communications satellites are relay links in space that provide a microwave radio relay device for point to point communications on earth

Transponder - A communications satellites channels are called transponders, because each is a separate transceiver or repeater

*Welcome and IntroductionDefinition of Terms continued

Carrier - A wave form, pulsed or continuous which is modulated by another information bearing wave form. The Hub station and every ship in the network transmits and receives digital carriers.

CW Continuous Wave carrier An unmodulated or pure carrier that is energy only carrier. It contains no information. Used to measure transmission power levels

Modulation The process of adding information to an electrical or optical carrier. In digital systems, an analog carrier signal is modulated by a digital bit stream

QPSK Quadrature Phase Shift Key A type of modulation that uses changes in phase of the carrier to represent characters

*Basic Satellite Information

Satellites are relay links (repeater) in space. They have very sophisticated antennas & RF equipmentThey have highly focused Antenna Patterns (footprints)They can utilize up to 350 Watts per Transponder

Based on function and purpose, they can have Low, Medium, or Geostationary orbits

They utilize either Linear or Circular polarization which requires the correctly polarized feed on the ships antenna

The ship must be in a strong enough area of the satellites footprint for antenna system to operate.

Satellites currently orbiting the earth represent a wide variety of sizes, shapes and capabilities, each designed for specific purposes.

Regardless of the type of signal, they are all relay devices, located in space to re-broadcast their signals to a much larger area than would be possible by local area (TV Station) transmissions.

The designed purpose dictates what type of orbit they are placed in, frequency band of operation, types of transmissions, power levels emitted and where their signal(s) are directed.

The different sizes and shapes vary widely, but all satellites have the same basic elements.

Stabilization, telemetry equipment, and boosters are all used to keep the satellite oriented properly in its' specific orbital position.

Solar panels and batteries are used to power the transmit and receive RF equipment and telemetry systems which are used to track & control the satellites' position.

*Types of Satellite OrbitsLEO (Low Earth Orbit)500 to 1000 miles above the earth

MEO (Medium Earth Orbits)8000 miles above the earth

GEO (Geostationary Earth Orbit)22,753.2 miles above the earthGEOMEOLEO

*Types of Satellite OrbitsOrbits

Satellites are launched using a variety of multi-stage rockets to get them up to a Transfer Orbit, where they can be maneuvered to the correct final orbit position. The most common orbits are:

Exploratory - These satellites are the "Deep Space" satellites which are launched for Scientific purposes such as to explore Mars, Venus and other planets or even solar systems

Polar Orbit - Low, or Medium, Earth Orbits (LEO/MEO) are orbits that are parallel to the earths axis. From a location on the earths surface these satellites appear to rise from a point on the horizon, pass across some portion of the sky descending to an opposite point on the horizon.

How many "passes" of a satellite over a specific location in a 24 hour period depends on the Number of satellites in orbit, their Altitude of orbit and the specific location on the earths surface. Examples of present services are Global Positioning System (GPS) and SAR-Sat (Search And Rescue) and GlobalStar Satellite Phone & Data services.

*Types of Satellite Orbits

Clarke Orbit

Named after the famous Science Fiction writer, Arthur C. Clarke, who first envisioned its' potential for global communications usage in 1945.

If a satellite is positioned 22,753 Statute Miles above the Equator, its' rotational speed will match that of the earth and, therefore, appear to remain in a fixed position when viewed from the earths surface. These satellites are referred to as "Geo-Synchronous" or "Geo-Stationary".

Many serve a wide variety of communications services including telephone, data, radio and television. These are the satellites that Seatel antenna systems are most commonly used with. They are all in orbit over the Equator (0 degrees Latitude) and so are usually referred to by their "longitudinal" position as often as by their name.

Starting from 0 degrees longitude increasing in degrees East or West to 180. At these two points a satellite could be called 0.0 degrees East or West, or 180 degrees East or West respectively.

It is also acceptable to refer to all satellites as some number of degrees EAST, ranging from 0.0-359.9 (this would mean that satellite 270.0E would be the same as the one called 90.0W ).

*Satellite Orbital Spacing

Orbital Spacing

In the simplest form 3 satellites would be required to provide global coverage, with each satellite illuminating about 42% of the earths surface.

As time has passed, the number of satellites in Geosynchronous orbit has increased to the present population of more than 130 satellites.

The satellite positions are regulated by multi-national organizations which use illumination area, frequency allocation and polarity usage to plan satellite positioning (for each type of services) in such a way as to provide for the greatest number of satellites possible without interfering with each other.

Good planning and co-operation are required to achieve the goal of locating the satellites 2 degrees apart from each other in longitudinal position.

*Basic Satellite Information Satellite RF Equipment

Each satellite has redundant Receive and Transmit equipment capable of operating in its' own assigned frequency band(s).

Satellites can employ multiple antennas, so they can have switching equipment that will direct selected transponder outputs to a particular antenna.

Multiple antennas provide multiple or spot beam footprints

Technological advances in microwave devices = the use of a greater number of possible frequency bands.

Better control of bandwidth used by each transponder = more transponder channels within each frequency band.

Some bands have even been split into multiple sub-bands because they are (now) being used so efficiently.

Some of the new hybrid satellites have 32 transponders which are capable of transmitting C and Ku Band simultaneously at high power levels (150-250 Watts).

*Basic Satellite Information The Antenna

Sophisticated satellite antenna designs provide highly focused illumination patterns that are called footprints.

Some of these illumination patterns are shaped to fit the geographic area of coverage.

Focusing and shaping the beam concentrates the transmitted energy into the footprint of the desired area of coverage without wasting any of it elsewhere.

This increases the overall receive level (Effective Isotropic Radiated Power -EIRP) throughout the footprint pattern, allowing smaller (lower gain) dishes to be used in receive only systems.

It also reduces the Gain over Temperature (G/T), requirements for TX/RX systems, allowing them to operate with smaller dishes and/or lower transmit power levels.

Some of these antennas provide very wide coverage allowing them to receive from, or transmit to, an area equal to about 40% of the earths surface (global beams)

*Basic Satellite InformationThe Relay Link

The satellite itself is a relay device, receiving and re-transmitting signals.

Transmitted signals originate from an Earth Station, or in special cases, another satellite.

These UPLINK signals are received at the satellite on one frequency, routed to the on-board conversion & transmission equipment, and transmitted as the DOWNLINK signal at a different frequency.

Transmissions from earth use higher frequencies while transmissions from satellites use lower frequencies. First satellites had limited power and lower frequencies have less attenuation (loss).

The received and transmitted signals may use the same antenna and be using the same area of coverage (footprint). This UP-DOWN link is called a single hop. Some signals require multiple satellites and are know as double hops

An "Earth Station", can be fixed or mobile. A fixed station is one which does not move (stationary position) and a mobile station is one which is capable of changing position (ie.. a news van, or a HiSeasNet ship).

*Intelsat 701 - Pacific Region C-BandIntelsat 701Located at longitude 180 West (or East)Provides C-Band coverage for HiSeasNet shipsNote decreasing G/T values from beam center to beam edge

*Intelsat 707 - Atlantic Region C-BandIntelsat 707 Located at longitude 307 degrees East (53 degrees West)Provides C-Band coverage for HiSeasNet shipsNote decreasing G/T values from beam center to edge

*Satmex 5 - Beam 1 Ku-Band

Satellite provides Ku-Band service for HiSeasNet ships and other usersBeam 1 covers Continental U.S. (including Pacific & Atlantic coasts), Mexico, and Gulf of Mexico Located at longitude of 116.8 degrees West (or 243.2 East)Shows EIRP Footprint contours (in dBW)Note decreasing EIRP values from beam center to edge

*Satmex 5 - Beam 2 Ku-Band

Satellite provides Ku-Band service for HiSeasNet ships and other usersBeam 2 covers Continental U.S. (including Pacific & Atlantic coasts), Mexico, and Gulf of Mexico, Caribbean Sea, majority of South America Located at longitude of 116.8 degrees West (or 243.2 East)Shows EIRP Footprint contours (in dbW)

*Satellite Frequency BandsFrequency Bands

A wide band of frequencies is shown in the next slide.

It is important to note that frequencies used by other Electronic Systems may interfere with the Satellite System. CB, TV UHF & VHF and especially Navigational RADARS are examples of sources of interference.

The next slide gives Uplink and Downlink frequencies of the Satellite Bands.

Note that several Sub-Bands maybe in use within what is commonly called C & Ku bands.

Certain sub-band usage may be restricted to a given geographic area in an effort to extend the maximum number of satellite signals in that area while minimizing interference.

*Standard Satellite Frequency Bands

BANDUPLINK FREQDOWNLINK FREQ(GHz)(GHz)S-Band5.925-6.0552.535-2.655

C-Band5.725-6.4253.700-4.2006.425-7.0754.500-4.800

X-Band7.900-8.4007.200-7.750

Ku-Band12.75-13.2510.700-12.70014.00-14.2512.500-12.75014.00-14.5010.950-12.20017.30-18.1011.700-12.50017.30-17.8012.200-12.750

Ka-Band27.00-43.0018.300-22.200

*Rain Fade Attenuation

Rain Fade is the common term for Rain Attenuation. This attenuation (or signal strength loss) is caused by the absorption of the satellite signals by heavy rain.

Below is a chart that shows typical attenuation based on rain rate with the subject antenna set to a 30 degree elevation angle

Rain Attenuation (dB) at 30deg

Rain Rate (mm/h)

4 GHz

6 GHz

12 GHz

14 GHz

5

.1

.15

1.6

1.8

10

.11

.80

2.0

2.9

15

.12

1.4

2.6

5.0

20

.13

1.6

3.3

6.8

25

.14

1.8

4.1

8.0

30

.15

2.0

5.0

9.2

35

.16

2.4

6.0

10.4

40

.17

2.8

7.0

11.8

*Satellite Frequency AdvantagesC-Band Frequencies

AdvantagesWide Footprint CoverageMinor Effect From Rain (Rain Fade)

DisadvantagesRequires Larger AntennasRequires Larger SSPAEffected by Terrestrial Interference (TI)Difficult to obtain a TX License

Ku-Band Frequencies

AdvantagesRequires Smaller AntennasRequires Smaller SSPAEasy to Obtain a TX License

DisadvantagesEffect by Rain (Rain Fade)Smaller Footprint

*Satellite Frequency Polarization

Frequency polarization is a technique designed to increase the capacity of the satellite transmission frequency.

In linear cross polarization schemes, half of a satellites transponders transmit their signals to earth in vertically polarized mode; the other half of the satellites transponders transmit their signals in horizontally polarized mode.

Although the two sets of frequencies overlap, they are 90 degree out of phase, and will not interfere with each other.

For both satellites and earth stations the normal configuration is to transmit in one polarization and receive in the opposite polarization.

*Satellite Polarization - Linear and CircularLinear & Circular WavesElectro-Magnetic transmissions are comprised ofElectric and Magnetic fields, which are inherently 90degrees apart in phase, and are called "E field" and"H field" respectively. These transmissions arereferred to by the orientation of their Electric field.

In a purely Vertical Linear wave the "E" field would be perfectly vertical. A Horizontal waves' "E" field is rotated exactly 90 degrees from the Vertical wave. In Circular transmissions the "E" field spins/rotates and is described by the direction, Right or Left handed, the "E" field is spinning as you view the wave. Right handed transmission must be received using Left handed polarization of the feed. A Teflon Dielectric wedge is usually placed in the OMT at a precise angular position to allow pick-off probes to "capture this signal for insertion into the C-Band waveguide Signal flow inside the rectangular waveguide section is oriented with the "E" field across the narrow dimension of the waveguide.

*Satellite Frequencies and TranspondersA Transponder contains a block of frequencies on a satellite. Typical bandwidth is 40MHz per transponder (36MHz usable - 2 MHz of guard band on each side). Some Ku-Band transponder are 54MHz & 72MHz.

Typical Ku-Band Satellite Transponder Plan

*Geostationary Satellites SUMMARY

Satellites are relay devices, re-broadcasting signals to a large area on earth (footprint)

They operate in a variety of frequency bands and can have multiple antennas which allow the transmitted energy to be aimed and focused very accurately in multiple beams.

The power of each beam dissipates as the area of coverage increases. Contour maps are published by the satellite owners that show the beams signal strength lessens as the footprint size increases.

They are in Geo-Synchronous Orbit over the Equator, therefore, appear to remain in a fixed position when viewed from the earths surface.

Because they are all at 0 degrees Latitude (Equator) they are commonly referred to by their Longitudinal position.

It is common for a satellite to alternate transponder polarities, (Horizontal & Vertical, or Right & Left hand Circular) to prevent interference of one channel to another, and for adjacent satellites to reverse their transponder polarities.

Other Electronic Systems may interfere with your Satellite System (CB, TV UHF & VHF and especially Navigational RADARS).

Satellite signals are typically focused, and aimed, at the populated land mass areas of the globe.

*Satellite Footprint Basics

Transmit power, beam-width, frequency band, and polarization mode are all important factors of the signal transmitted by the satellite. The ships location within the footprint, the overall gain of the system, blockages and atmospheric conditions are the primary factors in the systems ability to receive the signals from a desired satellite.

Transmit Power The transmit power of some satellites is as little as 8 Watts per transponder. Some newer satellites are capable of 350 Watt transmission. The higher the transmitted power level, the stronger the receive signal will be at any point within the footprint.

Transmitted Beam Width A fixed amount of power is being transmitted into the footprint area. The larger the area is (wider beam width), the lower the received signal level will be at any given point within that footprint. The smaller (narrower beam width) the footprint area is, the higher the received signal level will be at any point within it.

Frequency Band and Polarization Type The frequency of the transmission is not as important as the power level or beam-width, but lower frequencies offer a slightly better atmospheric penetration (less attenuation). Circular polarization also offers better penetration of fog and rain (over linear transmissions).

*Satellite Footprint Basics

Location

The signal level of a given footprint is always strongest in the center, decaying (basically in concentric rings) out to the fringes. However, these concentric rings are not necessarily uniform rings or circles. The further out from center beam each contour is, the lower the signal level is along its' circumference.

Because of this, the ships position is very important. This position may not even be in a footprint area, and even when the ship is in a footprint the antenna may not be receiving enough signal level for the DAC or the modem to be able to process it properly.

Be very careful in trying to interpret satellite footprint charts - they are mathematically generated patterns, (based on the antennas' performance before launch), overlaid on pictorial locations of earth. Also keep in mind that a given satellite can have multiple footprints, with some transponder signals in one but NOT in others.

In any given satellite footprint, atmospherics change through the day will cause the transponder signal levels to change accordingly.

Finally, signal levels may vary from one transponder to another.

*System Gain

System Gain - is a measure of the ability of the system to increase the power or amplitude of a signal

The overall gain of the Seatel antenna system determines its ability to receive enough signal for the DAC and Comtech modem to process it into usable data.

The System Gain is determined by the size and type of the reflector, the type and proper alignment of the feedhorn, Noise Figure rating of the Low Noise Converters (LNB or LNA), the RF receive equipment, the DAC and Modem receiver specs and all of the loss factors (primarily cables and splitters). This is of paramount importance when trying to receive weaker signals (when in "fringe" areas of the footprint, especially from satellites transmitting low power or wide beam patterns).

System Gain determines how far from beam center the "fringe area" is. The easiest way to determine the actual system performance is to observe where signals from a variety of satellites are lost, note that location and signal level from the footprint charts for those satellites.

This will show what the value of the weakest signal level your system performance allows, therefore, which level satellite footprint contour is the fringe area for the system.

*Satellite Beam (Footprint) PatternsSatellite Beam Patterns

The beam pattern of the signal transmitted by the satellite is a function of the antenna being used.

The pattern is based on the antennas' radiated field pattern when it was tested prior to launch.

A given amount of power spread over a wide area, such as a Global beam covering 42% of the earths surface, makes the signal level very weak at all locations within that area.

A Hemi-beam only covers about 20% of the earths surface and would have signal levels at least 3dB higher (half the area equals twice the effective power) throughout its' coverage.

Area beams cover about 10%, doubling the power again (another 3dB higher) over a Global beam and Spot beams may be as little as 2% (another 6 dB higher).

*System Block Diagrams

Basic System Components

The following pages show typical TX/RX System Block Diagrams for the three equipment configurations in the HiSeasNet network. They show the Basic System Components which include:

Above Deck Equipment (ADE)Antenna, Codan RF Equipment, Radome, Air Conditioner

Below Decks Equipment (BDE)Interface Panel, DAC, Comtech modem, Router

*Model 9797 C-Band Circular Antenna System

*Model 4996 Ku-Band Linear Antenna System

*Model 4006 & 6006 Ku-Band Linear Antenna Systems

*Typical Ship Level Diagram

Actual

Current

Scheduled

Legend:

FeedOMT

Waveguide

SSPA

IFL Cable Loss~4 dB

6 dBPad

Tx Reject

LNA

IFL Cable Loss~ 4 dB

3 waySplitter-4 dB

-22 dBm

F

J

A

B

C

D

E

G

I

J

L=0.1dB

L=1.0dB

L=0.2dB

Modem TX Level(-10 dBm)

Modem RX Level(-50 dBm)

IN

OUT

K

H

Gain = +50 dB

40 watts(46 dBm)

EIRP Tx

Rx Isotropic Level

-40 dBm

K

-10 dBm

-16 dBm

-20 dBm

+24 dBm

-44 dBm

-48 dBm

Typical Satellite LinkBlock & Level Diagram

-10

-90 dBm

Codan Converter~2 dB loss

-44

CodanConverter0 dB loss

+23

I

H

G

F

E

D

C

B

A

Typical Value (dBm)

+24

~ -130

Measurement Point

-22

-20

-16

-48

-90

-40

Free Space Loss 186 dB

*Basic System ComponentsAbove Decks Equipment (ADE)

*Basic System Components

Above Decks Equipment (ADE)

The Radome Assembly - Provides for the mechanical mounting and environmental protection of the antenna assembly.

The Support Assembly - Mechanical support for the antenna. Rigidly attached to the ship via the Base Frame, therefore, provides the antenna a mechanical reference to the bow-line of the ship.

AZ Spindle/Stabilization Section - (Also called the Azimuth Canister), Provides UNLIMITED Azimuth rotation, Lateral and Vertical shock isolation, AC Power and Dual Coaxial signal paths.

Equipment Frame, RF Equipment and the Antenna Section form the Stabilized Mass of the antenna.

Level cage is attached to the equipment frame and contains the Rate sensors (3) and Tilt sensor. Level cage is ONLY driven to initialize or change the ELEVATION angle of the dish.


28VDC Pedestal power supply has voltage select/fuse block which must be set correctly.

Pedestal Control Unit (PCU) initializes the antenna pedestal, is solely responsible for stabilization and carries out commands sent by the ACU.

Pedestal multiplexer (MUX) - 9600 baud asynchronous FSK modem. Converts RS-422 to RF and RF to RS-422 to provide for ACU-PCU communications (Pedestal M&C) across the coaxial path between the ADE & BDE.

A second MUX is provided on TX/RX systems for communication with the RF Equipment (Radio M&C).


Antenna Frame


Antenna & Feed

Reflector - The Gain & Efficiency of the dish is directly related to; Size of reflector, Type of reflecting surface (all 97 antenna systems use solid, precision reflectors with very accurate Parabolic curve) and the Focal type of the reflector

Prime Focus Feed, Scalar Ring, and Struts cause partial blockage of the receive signal and causes some interference with the transmitted signals. The result is incomplete and uneven illumination of the reflector.

Offset - Dish shape is a cutout of a section of an axis symmetric parabola. Feed and Struts are out of the signal path, (relative to the reflector), so they do not interfere with receive or transmit pattern. Result is complete illumination of reflector.

Cassegrain - Overall dimension from the dish to the far side of the Sub-Reflector is shorter (more compact). Sub-Reflector more evenly distributes illumination of the reflector. Result is signal path blockage by the sub-reflector is kept to minimum.

*Basic System Components

Above Decks Equipment (ADE)

Antenna & Feed

Scalar Plate - Improves the receive gain of the feed as much as 3dB by recovering stray receive energy and focuses transmit energy to improve illumination of the dish surface.

OMT (Orthogonal Mode Transition) - Transition from an Orthogonal Mode chamber to standard Waveguide flanges appropriate for the frequency of usage. Must be designed specifically for the frequency of operation, f/D ratio of the dish, and polarization mode (Linear and/or Circular) that will be used.

Polarization Angle (PolAng) motor - Polarity of the 24 VDC applied to the DC motor determines the direction of rotation. Rotates the OMT to optimize its Linear (electrical) angle to match that of the desired satellite .

Waveguide FiltersBand Pass Filters - Passes only the desired band of frequencies, attenuating others (Radar Filter). Transmit Reject Filter - Passes the desired receive band and specifically rejects the transmit band. Receive Reject Filter - Passes the desired transmit band and specifically rejects the receive band

LNAs, LNBs, and LNCsLow Noise Amplifiers (RF), Low Noise Block (down) Converters (500 MHz band-pass output, or more) and Low Noise Converters (36 MHz band-pass output for 70 MHz systems). LNA C-Band frequency to Codan ConverterLNB Ku-Band downconverted to L-BandLNC Not Used in HiSeasNet equipment


Antenna & Feed

*Basic System ComponentsBelow Decks Equipment (BDE) Antenna Controller - DAC

*The basic functions of the front panel keys, display and LEDs are:

DISPLAY - 20 character x 2-line display of all menu display, entry, control and status windows.

AUX1 - Toggles Tracking ON/OFF, regardless of which displayed menu location you are currently in. AUX2 - No current operator function.

Main Menu Display & Entry Keys:

SHIP - Access the SHIP menus to display, enter or edit current Ships Latitude, Longitude and Heading information. SAT - Access the SAT menus to display, enter or edit current Satellite Longitude, Threshold, Satellite ID, Tracking Receiver settings, Network ID and current signal level being received (AGC). ANT - Access the ANTENNA menus to display, enter or edit Azimuth, Elevation & Relative antenna position and Polarization setting. Received signal level, (AGC), and Dishscan tracking signals are found in sub-menu screens MODE - Access control of Tracking band & ON/OFF selection, Searching ON/OFF selection, and Error status and Remote. Provides access to the DAC Setup Parameters and Remote Command, Remote Monitor, & Remote Tilt FunctionsKEY PAD - Used to key in numeric values in all entry menus. NUMBERS - Key in numeric value of desired entry. May be used in conjunction with the Decimal Point to enter whole and tenths of degrees or MHz & KHz to enter tuning frequency. C - Clear an incorrect numeric entry. Special Keys -UP/DOWN Arrows - Steps the selected entry UP or DOWN one increment per sequential key-press or rapidly increments the selected entry when pressed & held. Affects all Numeric entries and is used to toggle Tracking ON/OFF, turn Searching ON or to clear the Error display.

*Below Decks Equipment (BDE)

DAC Main Menu Display & Entry Keys (continued)

N/S/E/W - Toggles North/South Latitude entry, East/West Longitude entry, Tracking Receiver Input selection and Polarization mode. Also used to change numeric entries to negative values. When in MODE menus the N/S/E/W key steps the display back UP to the previous sub-menu.

ENTER - Enters the value that has been keyed in.

Status LEDs

TRACKING - ON indicates that DAC is Tracking a satellite signal whose AGC value is greater than (Green LED) the Threshold value. The DAC is actively issuing small azimuth & elevation position ONadjustments to the antenna to optimize the signal level (AGC). If the system was Searching, SEARCH will go OFF when TRACKING turns ON.

Blinking - indicates that the satellite signal AGC value is less than the Threshold value. DAC is counting down the SEARCH DELAY (seconds). If DAC does not rise above the Threshold before the count-down is completed, the DAC will automatically start, or continue, a SEARCH to acquire a signal that is greater than Threshold.

OFF - indicates that Tracking is OFF. This may be due to operator action, or that Tracking was pre-empted by SEARCH.


DAC Main Menu Display & Entry Keys (continued)

SEARCHING -ON indicates that the ACU is Searching for a signal whose AGC value is greater than (GREEN LED)the Threshold value. When a signal is found, SEARCH will go OFF and TRACKING ONwill come ON. If an adequate signal is not found during the Search, SEARCH light will blink as the antenna re-targets to the desired satellite. If an adequate signal is still not found, then TRACKING will begin flashing (count-down) until the next SEARCH is automatically started.

Blinking - This indicates that the antenna is TARGETING (moving) to the calculated Azimuth & Elevation positions of the desired satellite. When the antenna arrives at the calculated position , SEARCH will go OFF. If an adequate signal is found at the targeted position Tracking will commence. If an adequate signal is not found at the targeted position, TRACKING will begin blinking (see above) until the next SEARCH is automatically started.

OFF - This indicates that SEARCH is OFF. This may be due to operator action, or that Tracking has pre-empted SEARCH.

UNWRAP - (Red LED) Not used on these systems, this LED should never be ON.

ERROR - ON indicates that one, or more, discrete system errors have occurred. The MODE (RED LED)button is used to view the error code or use DacRemP to view the error information.

OFF This indicates that no errors have occurred.

RESET - Resets the processors inside the ACU. This does NOT reset the antenna pedestal

*Below Decks Equipment (BDE)DAC Rear Panel Connections


FRONT PANEL

Status indicator6 LEDs to indicate Tracking, Searching, Target, Power, Initializing, and Error

Alpha Numeric Display2 line 20 character Alpha Numeric

Next ButtonCycles Display between Ship, Satellite, Antenna, and Status

4-Position KeypadCycles Cursor Up, Down, Left, Right

Enter Button

Reset Button

Controls:AC Power On / OffSeatel DAC-2200 Front and Rear Panels

*Below Decks Equipment (BDE)Seatel DAC-2200 Front and Rear Panels

Rear Panel Connectors

J1 Gyro Compass25 pin female D-SubminiatureJ2 NMEA RS-422 Serial I/O9 pin male D-SubminiatureJ3 M&C RS-422 Serial I/O9 pin female D-SubminiatureJ4A Antenna Control 9 pin male D-SubminiatureJ4B RF and Pedestal DC PowerType BNC femaleJ6 RF IN Tracking ReceiverType F femaleIF InputJ7 RF OUT Tracking Receiver Type F femaleIF OutputAC Input PowerIEC receptacle with power cord Ethernet ConnectorStandard

*Below Decks Equipment (BDE)DAC Inputs and Setup

*Below Decks Equipment (BDE)DAC Inputs & Setup

*Below Decks Equipment (BDE) DAC Inputs and Setup

Satellite Reference Mode

The ships gyro compass input to the DAC may be accurate and stable in static conditions and yet may NOT be accurate or stable enough in some underway dynamic conditions. If there is no gyro compass or if the input is corrupt, not stable, or not consistently accurate, the tracking errors will become large enough to cause the antenna to be miss-pointed off satellite.

Satellite Reference Mode will uncouple the gyro reference from the azimuth rate sensor control loop. When operating in Satellite Reference Mode changes in ships gyro reading will not directly affect the azimuth control loop.

The Pedestal Control Unit (PCU), will stabilize the antenna based entirely on the Latitude and Longitude, the azimuth rate sensor loop (Level Cage), and the tracking information from DishScan (AGC Level).

Satellite Reference Mode can be used as a diagnostic tool to determine if tracking errors are caused by faulty gyro inputs.

Satellite Reference Mode MUST be used when:1. No Gyro Compass is available2. Frequent or constant ACU Error Code 0001 (Gyro Compass has failed)3. Gyro Compass output is NMEA heading4. Flux Gate Compass is being used5. GPS based Satellite Compass is being used

*Below Decks Equipment (BDE) Basic System Functions

Antenna Control Unit (DAC)- Master, controls antenna through the PCU Interface with Ships Gyro Compass Interface for GPS input Interface with computer to Monitor and Control the ACUControls Pointing and Targeting of the antennaControls Tracking

Pedestal Control Unit (PCU) - RemoteInitializes the antenna pedestal Reads sensors Controls Motors Controls Stabilization of the antenna Takes pointing and tracking direction from the ACU

ACU PCU Control Signals - Pedestal M&C DAC RS422 input/output via Pedestal (FSK modem) MUX (TX = 1.1MHz, RX = 1.5MHz)PCU RS422 input/output via Base (FSK modem) MUX (RX = 1.1MHz, TX = 1.5MHz)Base and Pedestal FSK modems are mirror tuned so operate in pairs

*Antenna Pointing, Targeting, and Tracking

Antenna Pointing - The process of accurately pointing the antenna to a specific angular position (satellite location), in 3-dimensional free space. This process is controlled by the Antenna Control Unit (DAC). It requires that the antenna is capable of moving in all three axes (Azimuth, Elevation, and cross Level)

Satellite Targeting - This process is the beginning of a search for the satellite by the antenna. The process is controlled by the DAC. The DAC has calculated the 3 dimensional location of the satellite based on the GPS, GYRO, HDG, Sat Long and is now moving the antenna to point at that location.

Satellite Tracking This is the process of the DAC actively optimizing the pointing of the dish for maximum signal reception. This process is accomplished by continuously making small movements of the dish while monitoring the AGC level of the received signal. Evaluation of this information is used to constantly make minor pointing corrections to keep the signal level peaked as part of normal operation.

Theory of Stabilization

The antenna system is mounted on a 3-axis stabilization assembly that provides free motion in the 3 axes.

Assembly allows the inertia of the antenna system to hold the antenna pointed motionless in inertial space while the ship moves beneath it.

Low friction torque motors attached to each of the three axes of the assembly - Azimuth, Level (elevation), & Cross Level provide the required force to overcome the disturbing torque imposed on the antenna system by cable restraints, bearing friction, and small air currents within the radome.

These motors are also used to re-position the antenna in Azimuth and Elevation.

The Pedestal Control Unit (PCU), uses inputs from the Level Cage sensors to calculate the amount of torque required in each axis to keep the antenna pointed within +/- -0.2 degrees.

Theory of Stabilization(cont)The antenna is controlled by three independent Control Loops (AZ, LV, CL).

The primary sensor input for each control loop is the rate sensor mounted in the Level Cage Assembly.

This sensor reports all motion of the antenna to the PCU. The PCU immediately responds by applying a torque in the opposite direction of the disturbance which brings the antenna back to its desired position.

Both the instantaneous output of the rate sensor (Velocity Error) and the integrated output of the rate sensor (Position Error) are used to achieve high pointing accuracy.

The calculated torque commands are converted to a 5 volt differential analog signal by a Digital to Analog converter (D/A) and sent to each of three brushless Servo Amplifiers.

These amplifiers provide the proper drive polarities and commutation required to operate the brushless DC Servo Motors in torque mode. The torque acting on the mass of the antenna cause it to move, restoring the rate sensors to their original position and closing the control loop.

Theory of Stabilization(cont)

Since the rate sensors only monitor motion and not absolute position, a second input is required in each axis as a long term reference to keep the antenna from slowly drifting in position.

The Level and Cross Level reference is provided by a 2-axis tilt sensor in the level cage assembly.

The Azimuth reference is provided by combining the ships Gyro compass input and the antenna relative position

*Antenna Initialization The Initialization process is controlled by the PCU.

Every time the antenna is energized (or commanded to re-initialize), the PCU initializes the antenna in the following phases. Each phase must complete properly for the antenna to function properly.

Level Cage Activates - Level Cage is driven in one direction (CW or CCW),to a mechanical stop, issuing extra steps to assure that the cage is driven all the way to the stop. Then the PCU will rotate the Level Cage in the opposite direction a calculated distance.

Elevation axis activates - Feedback from the Elevation axis of the tilt sensor (Gravity Reference Sensor inside the Level Cage), to the PCU is used by the PCU to drive the Elevation of the antenna to 45.0 degrees (the LV tilt sensor (Elevation) axis of the Level Cage should now be level)

Cross-Level axis activates Feedback from the CL axis of the tilt sensor (Gravity Reference Sensor inside the Level Cage), is used by the PCU to drive the Cross-Level tilt of the antenna to level (brings the antenna Cross-Level Beam, and the tilt sensor CL axis of the Level Cage, to level).

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 (9797 antennas), or by a Hall Effect sensor in close proximity to a magnet (4996, 4006 & 6006 antennas). The antenna should now be facing the BOW of the ship

This completes the phases of antenna initialization. At this time the antenna elevation should be 45.0 degrees and Relative azimuth should be at be at the home flag (home switch engaged on the home flag cam).

*Antenna StabilizationThe PCU is responsible for Antenna Stabilization.

The PCU sends commands to the antenna motors to maintain the antenna at the AZ & EL positions calculated by the DAC. However, the antennas Inertia, or its tendency to remain at rest, is the critical factor in stabilization. The PCU relies on the antenna inertia to provide most of the stabilization (>90%). Inertia is affected by:

1. Antenna balanceLoose cables will affect antenna balance. In extreme situations, an out of balance antenna will cause pedestal errors.

2. Bearing dragBearings in the Elevation, Cross-Level, and Azimuth axes can fail and would have to be replaced. Failed (or failing) bearings will cause a pedestal error on the DAC

3. Mechanical bindingWorn or failing belts and motors will affect performance and usually cause drag to the antenna movements. This drag will cause pedestal errors

4. Cable restrictions Loose cables and/or worn springs can cause unexpected movement of the antenna in rough weather conditions. These movements will cause pedestal errors

*Antenna Stabilization Components of Stabilization

Level CageThree (3) Rate Sensors - Azimuth, Level and Cross-Level These sensors measure changes in DC voltage in each of the three axes when force is exerted on the antenna. They send feedback of the voltage changes to the PCU. The output of each sensor to the PCU is 2.50VDC +/- 100mV (NOM) when the rate sensor is NOT being rotated.

Right-Hand Rule device - Right-hand (CW) rotation causes the voltage output to increase. Left-hand (CCW) rotation causes the voltage output to decrease.

Two (2) Gravity Reference Tilt Sensors These sensors provide feedback to the PCU when the Level Cage is not level in either or both the LV CL axes. Conductivity of the sensor probes is directly proportional to amount of conductive liquid coverage of the probes (acting like a potentiometer, with the center probe representing the wiper) 2.50VDC (NOM) into the A-D circuit in the PCU when the tilt sensor is level.

*Antenna Stabilization (cont)Level Cage Stepper Motor - Drives the level cage ONLY to initialize or change Elevation position. Elevation display is based on steps issued by the PCU, no positive feedback is provided.

Servo Amp/Motor Controllers - Commutates and controls the Brush-Less DC motors that control antenna movement.

BLDC Motors (Torque Motors) - Hall sensor feedback to the Servo Amp/Motor Controller enable them to commutate with the motor.

Azimuth Encoder - Digital output into the PCU Relative position counter. Position counter is pre-set by the home switch once each revolution of the antenna.

Home Switch - Cam on the Azimuth driven sprocket contacts Home Switch once each revolution of the antenna. This input to the PCU pre-sets the Relative position counter (to the Home Flag Offset value stored in NVRam).

*Antenna Stabilization(cont)

*Antenna Stabilization (cont)Antenna balance

1. Reduces the load on the motors and increases longevity

2. Helps maintain nominal current flow through Servo Amplifier/Motor Controllers and reduces wear.

3. Responsible for 75% of the stability of the antenna - Top/bottom balancing Front/rear balancing & Left/Right balancing

4. Assists in maintaining antenna inertia

Balancing Lab

*Antenna - TrackingTracking - occurs after the antenna is stabilized at the correct Azimuth & Elevation angles and is receiving a signal of higher amplitude than the threshold level

DishScan Operation

DishScan -This system is a variation of Conical scanning, which continuously drives the antenna in a very small diameter circle at 60 RPM. The received signal is evaluated throughout each full circle rotation of the antenna to determine where the strongest signal level is, and will issue the appropriate Azimuth and/or Elevation steps to the antenna, as needed, 60 times per minute.

When The DAC is in the AZIMUTH or ELEVATION entry menu, the DishScan commands (2, 4, 6 or 8) will be visible in the lower left corner of the display.Antenna Movement2 = DOWN4 = LEFT6 = RIGHT8 = UP.When Tracking is turned OFF, these commands indicate the movement direction that is needed, but the commands will not be issued to the antenna to actually re-position it. Tracking must be turned ON to keep the antenna peaked on the satellite.

*Antenna Tracking(cont)DishScan (continued)

If the antenna is already perfectly pointed, the signal received (AGC level) throughout each full circle will be equal. If the dish is slightly mis-pointed, a portion of the circle movement will have higher signal level than the rest of the circle. DishScan will then issue a step in Azimuth, and/or Elevation, to move the antenna in the direction of the stronger signal.

[EXAMPLE: If the dish is mis-pointed slightly to the LEFT of the satellite peak; as DishScan drives the antenna through one circle rotation it will evaluate that the signal is slightly higher to the RIGHT, therefore, a RIGHT (Azimuth UP) step will be issued to the antenna].

The internal tracking receiver settings must be set correctly and the EL STEP SIZE, AZ STEP SIZE and STEP INTEGRAL parameters must all be set to 0000 for DishScan to operate properly.

*Antenna Tracking(cont)

Antenna Tracking Test

The best way to test tracking (regardless of which tracking mode is being used) is to test each of the 4 quadrants (UP, DOWN, LEFT & RIGHT of peak signal AZ/EL pointing). This will confirm that regardless the tracking mode (Conscan or Dishscan) being used drives the antenna back to peak satellite signal level .

1. Confirm tracking is on and record maximum AGC level on DAC front panel

2. Turn off tracking, and manually mis-point the antenna in one quadrant

3. Confirm that antenna is off peak signal by viewing reduced AGC level

4. Turn tacking back on and verify that the antenna automatically returns to peak signal level (peak AGC level) 5. Repeat steps 1, 2, & 3 for the other three quadrants.

*Antenna Tracking(cont) Antenna Tracking

AGC - The internal tuner card of the DAC provides a DC voltage output that is directly proportional to the level of the satellite signal input. The receiver output will be positive (voltage increases as satellite signal level increases) between 0.00-5.00 VDC.

This output is converted from the analog voltage to a digital value by an A/D converter on the DAC Main PCB. 30-40 digital counts of AGC is approximately 1dB of satellite signal. Satellite IF signal is provided into the internal tuner card of the DAC-97 or DAC 2200 using the BNC or F connectors mounted in the rear panel.

Receiver selection and tuning is set by using the front panel keypads on the DAC. The input is selected by pressing the required keys until the appropriate input is selected. Selections are Ext AGC (external connection to the Terminal Mounting Strip), or IF (70/140 MHz SCPC BNC connector input).

For the HiSeasNet systems, the correct selection is the IF. Enter the correct IF frequency supplied by the HiSeasNet Technical Team.

EXAMPLE: For the IF frequency of 64.800 MHz, press the numbers 68 then press ENTER. Next press decimal point . and then 800 and then ENTER

*Antenna Tracking (cont)

AGC vs. Pointing - As the antenna is moved in either AZ or EL through a satellite, from an off satellite position, through peak satellite reception to an opposite off satellite position, the AGC value on the DAC will be seen to change.

At an off satellite position, the AGC value will be at or near the noise floor and below the Threshold value. The AGC value will then rise rapidly to a peak value as the antenna moves through the satellite signal, and then fall rapidly back to a level at or near the value of the noise floor.

If the antenna position vs. AGC value was plotted on a Graph, it would look similar to the graph at the right.

Note the following: AGC value equal or near to the background noise level when at an off satellite position.

Peak AGC level when antenna is Peaked on satellite signal.

AGC delta (difference in AGC value between off satellite and peak satellite). Note that this has a direct relationship to the C/N of the satellite signal. (30-40 counts of AGC = approx. 1dB of signal strength.

*Antenna SearchingSearching Operation

A search pattern will automatically be initiated when AGC falls below the current Threshold setting (indicates that satellite signal has been lost). The search, its pattern dimensions and timing are determined by the SETUP searching parameters SEARCH INC, SEARCH LIMIT and SEARCH DELAY. Search is also affected by the Threshold and the internal receiver settings underthe Satellite menu. Search is conducted in a two-axis pattern consisting of alternate movementsin azimuth and elevation (forming an expandingsquare). The size and direction of the movements are increased and reversed every other timeresulting in an increasing spiral pattern as shown.

A Search can be initiated manually by selecting the Status - Searching menu and pressing the UP key. While in the Searching window, pressing the DOWN key will stop a search. Search is terminated automatically when the AGC level exceeds the threshold value.

*Installation Location - Site Survey ConsiderationsCheck for potential blockage from mast, stack or other structuresCheck for sources of other RF interference (radar)

Above Deck installationAssemble radome base frame. Connect all parts using supplied hardware. Once all parts are connected, torque all hardware.

Assemble lower half of the radome Connect all radome panels to each other and to the radome base. Leave hardware loose. This will leave an open space between the panel seams. Once all lower panels are interconnected, apply silicone to one seam, and tighten all hardware. Repeat for all remaining seams.

Assemble upper half of the radomeConnect all radome panels to each other. (Be sure to elevate bottom edge of panels off the ground using wood blocks from the shipping crates). Leave all hardware loose to create open space between all panel seams. Once all panels are connected, one person will be inside the radome. This person will apply silicone to each seam and then tighten hardware.

*Installation(cont)

Place top circular panel in opening at top of radome, apply silicone and tighten hardware. Lift one edge of assembled radome to supply access for the assembler to exit.

Assemble reflector assembly (dish, feed and struts)Lift antenna pedestal into lower radome halfLocktite and tighten all hardware.Lift and attach reflector and RF equipment

Lift radome top half onto lower halfAttach lifting sling to top half of radome at 4 equidistant points.Lift top half of radome onto bottom half and align bolt holesLoosely Install bolts and nuts-Leave open space between radome halves using available spacers.Apply silicone between the radome halves and tighten hardware.

*Installation(cont)

Attach Radome to shipLift completed radome assembly to mounting location on shipBolt or weld radome base legs to ship as determined by ships captain or other authorized personnel.WiringInstall, route and terminate 110 VAC power wires to antenna pedestal breaker box.Install, route, and terminate the 220 VAC power wires to the air conditioner unit.Install, route and terminate IF cables inside the radome at the IFL interface panel.

Below Deck Installation Install the ACU and interface panel in the equipment rack Terminate all power and signal cables to ACU and tie wrap in place

Confirm Antenna control connectionsIF cables confirm they are connected inside radome and at below decks interface panelShips gyro and NMEA signals confirm they are being receive by the DACOptional remote Radio M&C Terminal or personal computer (PCDAC and/or DacRemP) Install and connect other BDE equipment. (MUX, router, etc..)

*System Setup

After the physical installation of the Above Decks Equipment (antenna & radome) and the Below Decks Equipment (DAC, Modem, Mux) is complete, the system setup can begin. The setup includes the following

Above Deck Equipment (Antenna)Check antenna freedom of motion Check all cable connections Check antenna balance

Energize antenna Apply AC power to the antenna and confirm the initialization process is completed correctly. Note the mechanical position of reflector pointing when at home switch to calculate Home Flag Offset Home Flag Offset (HFO) = (( Mech/360) x 255)

Below Deck Equipment Apply power to the DAC. Confirm that the LCD screen first shows the DAC model and firmware version and then shows the PCU configuration and firmware version. Then go to the Setup window and program the DAC parameters

*DAC Setup ParametersSetup Parameters These parameter values can be accessed and changed either through the DAC front panel after entering the SETUP screens, or by using DacRemP.

Most of the factory default values should not need to be changed but a complete review of all parameter settings is required.

Brief descriptions of the parameters follow.

EL TRIM0000Unique to each installationAZ TRIM0000Unique to each installationAUTO THRES128Adjusted to each systemEL STEP SIZE0000Set to 0 for DishScanAZ STEP SIZE0000Set to 0 for DishScanSTEP INTEGRAL0000Set to 0 for DishScanSEARCH INC0010Search pattern step incrementSEARCH LIMIT0100Search pattern LimitSEARCH DELAY0030Time DAC waits to start searchSTEP DELAY0002Time between movements of antenna SYSTEM TYPE0013Selects System Options (see table)GYRO TYPE0002Selects Gyro Type (see table)POLANG TYPE0009 OR 0072Manual (9) or Auto (72)POL OFFSET0030Default is 30 can be adjusted if reqdPOLE SCALE0090Default is 90AZ LIMIT 10000Based on ship blockageAZ LIMIT 20000Based on ship blockageTX POLARITY0002 OR 0004Vertical is 2 Horizontal is 4

*System Setup(cont) Antenna Control Unit (DAC) Setup Parameters

Mode Button (DAC 97)- Displays Setup Parameter Displays and is Password protected area. These parameters establish how the system will behave by enabling or disabling hardware and software options. The DAC Setup Parameters are:

EL TRIM - Used to adjust the displayed elevation value when ON satellite peak to agree with mathematically calculated value. Trim value entered is the number of tenths, positive or negative, required to correct the on satellite elevation. NSEW key is used to toggle the entry to negative value. Should be re-evaluated every time the antenna is re-balanced. Azimuth and Elevation trim values must be set correctly for targeting to be accurate.

AZ TRIM - Used to adjust the displayed azimuth value when ON Satellite peak to agree with mathematically calculated value. Does not affect REL azimuth reading. Trim value is entered as the number of tenths (positive or negative) required to correct the ON satellite true azimuth. NS/EW key (DAC 97), is used to toggle the entry to negative value. Azimuth and Elevation trim values must be set correctly for targeting to be accurate Increase number to increase the resultant azimuth display.

*System Setup(cont)DAC Setup Parameters (continued)

AUTO THRES DAC sets threshold value of AGC counts above the average noise floor. Auto threshold programming code runs whenever the antenna is targeting or searching, integrating the average AGC over the past 6 seconds.

When the AGC rises faster than the auto-threshold can adjust, the sum (THRSH=average AGC plus auto thrsh) is saved as the current Threshold value.

Threshold is the value stored in RAM that the processor uses as a minimum acceptable AGC. When AGC falls below THRES the ACU will wait for search delay amount of time and then initiate a search. Units are in A/D counts, approximately 30 counts/dB (default setting is 128). A setting of 0 disables auto threshold.

EL STEP SIZE - Sets elevation sensitivity in Conscan/Dishscan mode, acts as a divider to determine how many of the elevation commands from the Conscan controller are actually sent through the PCU to the elevation motor.

A zero value sends all Conscan/Dishscan elevation commands through, each increment greater than zero divides by two (a setting of 3 would divide the number of commands actually sent to the motor by 8). Range is 0-255 steps. The value must be entered in the DAC field twice within 3 seconds to be accepted.

*System Setup(cont) DAC Parameters (continued)

AZ STEP SIZE - Sets azimuth sensitivity in Dishscan mode, acting as a divider to determine how many of the azimuth commands from the Dishscan controller are actually sent through the PCU to the azimuth motor.

A zero value sends all Dishscan azimuth commands through, each increment greater than zero divides by two (a setting of 3 would divide the number of commands actually sent to the motor by 8). Range is 0-255 steps. The value must be entered in the DAC field twice within 3 seconds to be accepted.

STEP INTEGRAL - Dishscan setting is 0000 (zero). Any non-zero value disables Dishscan.

SEARCH INC - Sets size of search pattern increment. Units are in pedestal step resolution (1/24 degree). The suggested setting is equal to 1/2 the 3dB beamwidth (factory default). Range is 0-255 steps.

SEARCH LIMIT - Sets the overall peak to peak size of the search pattern. Units are in pedestal step resolution. Range is 0-255 steps. After optimizing Targeting you may want to reduce the Search Limit size to help prevent tracking onto an adjacent satellite.

SEARCH DELAY - Time delay (in seconds) until a search begins after the AGC value drops below threshold. Range is 0-255 seconds, 0000 disables automatic search.

*System Setup(cont)STEP DELAY/Step Delay should always be set to factory default. Sweep SWEEP INCIncrement should be set to 0000 unless GYRO TYPE is set to 0000 (No Gyro/Heading input NOT available). When Gyro Type is set to 0000, the Sweep Increment set the azimuth sweep rate during the linear azimuth search.

SYSTEM TYPE - List of functional options each having a numerical value. Enter the sum of the desired options.

GYRO TYPE - Select the appropriate type of gyro compass input (also depends on the synchro adapter installed on the main PCB).

POLANG TYPE - List of functions each having a numerical value. Enter the sum of the desired functions based on desired displays AND capabilities of the antenna feed. For Linear feed systems (HiSeasNet Ku-Band antennas), 72 is AUTO mode and 9 is MANUAL mode. Antennas should be set to AUTO.

POL OFFSET - Used to optimize the linear polarization angle of the feed while in Auto-Pol mode.

POL SCALE - 90 degree 24V PolAng pot motion scale factor

*System Setup(cont)

AZ LIMIT 1 - Lower Relative AZ limit for pattern blockage mapping (DAC-03 & DAC 2200 have 3 zones instead of only 1)

AZ LIMIT 2 - Upper Relative AZ limit for pattern blockage mapping (DAC-03 & DAC 2200 have 3 zones instead of only 1)TX POLARITY - Selects TX polarity override. 0=no TX polarity override, 2=Vertical TX polarity and 4=Horizontal TX polarity. When switching from 2-4, or 4-2, feed will drive exactly 90 degrees.

SAVE NEW PARAMETERS - Press the UP Arrow key and then the ENTER key to save/write recent changes to NVRam. Press AUX2 and CLEAR simultaneously to access this function directly from any other mode.

REMOTE COMMAND WINDOW - Used to enter diagnostic commands

REMOTE MONITOR WINDOW - Used to monitor some diagnostic command results

REMOTE TILT WINDOW- Used to adjust the level cage after replacement ONLY if it is not level after antenna is initialized.

*Operation

Target Satellite - Verify Manual operation and control of antenna & peak on satelliteConfirm that antenna moves to calculated satellite location and begins an automatic search upon issuing a Target command.

Optimize SystemAdjust PolAng (if required only used on Linear Polarized systems)Program/Confirm DAC Internal tuner frequency (Satellite IF frequency)Confirm proper operation of Dishscan check parameters and personally view antenna motionAdjust AZ & EL Trim ValuesProgram Home Flag Offset (HFO) if required

Final checkout - May be helpful to have an assistant with a 2-way radioConfirm antenna finds satellite after Trim & HFO adjustments are programmedEvaluate auto-threshold value - Is Peak AGC value at least 50 100 counts above Threshold??Verifying Tracking - Perform Four quadrant tracking testObserve the antenna to ensure it remains stable and tracks a satellite (while under way if possible).Make sure no fasteners or radome hardware have come loose and that radome is sealed properlyClean up the radome interior.

*Functional Testing

Above Deck EquipmentCheck antenna freedom of motion no binding or frictionCheck feed alignment feed struts are tight and secureCheck antenna balance

Energize Antenna View initialization sequence. Confirm process is completed correctly. Also note mechanical position of reflector pointing when antenna is at the mechanical home switch to calculate the Home Flag Offset

Below Deck EquipmentSet/Confirm all parameters on ACUCheck System type Tracking parametersConfirm Gyro Compass TypeHome Flag Offset if requiredConfirm Gyro Compass Heading & DAC Heading are equalVessel position (automatic if GPS input is used)Confirm and save Internal tuner selection and tuning frequencyVerify Correct satellite longitude is entered in DAC

*Functional Testing(cont)

Functional Testing - Check each function to assure proper operation, DAC Power is" ON, and Verify DAC/PCU communications

Ships Heading - Confirm Initial setting and subsequent updating of the heading correctly follows the ships gyro compass.

LAT/LONG - Verify manual entry and automatic GPS updates to the DAC from the ships Gyrocompass system.

Internal Tuner Selection Confirm DAC tracking frequency is set to the carrier & Frequency specified by HiSeasNet Technical Team. Never use the TX IF frequency.

Feed polarization -Verify that polarization of the feed is operating properly in manual and/or automatic modes. (Used only on Linear Polarized satellites)

*Functional Testing

Satellite Targeting - Verify that antenna is driven to within +/- 1.0 degrees of the satellite position (evaluate and set AZ & EL Trim values as needed to assure targeting is within this spec).

Satellite Search - Verify that the delay, increment and limit parameters are set for the best performance. These values will be initially specified by HiSeasNet Customer Support but can be adjusted based on particular satellite AGC performance -Verify that the AGC level is proportional to the satellite signal level as the antenna is stepped from OFF satellite, through peak satellite signal to OFF satellite without being clipped off.

Side-Lobe Presence -High side-lobes on specific satellite may require auto threshold value to be set differently.

Tracking Setup - Band selection, step sizes and step integration (may involve system type setting also).

*Functional Testing(cont)

Optimize all other BDE Components (as required)

Verify proper antenna stabilization during ship motion, using any of the following: On satellite performance Remote Commands & monitoring PC diagnostic programs

Commissioning - Commissioning the system includes accomplishing all of the functional testing above plus verifying that all of the other BDE equipment operates properly.

TX/RX Systems - Test Modem, multiplexer and other equipment for proper services.Accomplish testing and commissioning as required with the satellite operator (i.e. side lobe testing and optimizing cross-pol isolation (optimizing polarization).Set final TX & RX signal levels with HiSeasNet Technical Team and Satellite Operator.

*Troubleshooting and Repair Antenna System

Required Test equipment1.Voltmeter (for checking Ac & DC power)2.Spectrum analyzer (if available) to view satellite reception and station TX carrier3.Test Cables (coaxial)4.Computer with Seatel Diagnostic Software & Hyper Terminal software ( for communications with the DAC and RF equipment)5.System block diagram (Test Points) Refer to Antenna & DAC Installation manuals

Check Component Functions

ADE components Radome, Base, Air Conditioner, IFL Cables for damage or unusual circumstances.

Pedestal components power off antenna and manually move antenna in all three planes (AZ, LV, CL). Check for binding, or any resistance. Antenna should move freely in all directions. Check all belts for wear.

Stabilization components Check/Confirm antenna Balance. Look for loose coaxial or other cables and secure them as required. Check Level Cage and motor for free movement.

*Troubleshooting and Repair (cont)Antenna System

RF (Radio) Equipment - Check Converter window for Power and Alarm LEDs. Use Hyper Terminal to Check/Confirm parameter settings. For BUC systems check Comtech modem for BUC parameters. Troubleshoot and Clear all error conditions.

Below Deck Equipment (BDE) Components

Antenna Control Unit Check DAC front panel for alarms and confirm all parameter settings. Use DacRemP to query the PCU and to check Sat Ref, Dishscan & Error Status. Also check coax cable connections, RX Splitter, Comtech Modem, Multiplexer, Computer and other ancillary equipment.

Comm Errors / Check DAC error screen for Comm (L) and System (R) System Errorserrors. Continuous increase of Comm Errors indicates loss of signal and possible failure of Rotary Joint, RF modems (either Pedestal or Base), or IFL cable problem. Use DacRemP to decode system errors

GPS & GYRO Signals Verify the DAC shows correct values for LAT, LONG, and HDG. Confirm the DAC is being updated by ships systems. Wrong numbers or no updates indicate loss of signal from ships systems.


DacRemP - Use DacRemP to check and decode system errors

DAC AGC & Check both parameters on DAC front panel and confirm both values Threshold Levelsare greater then 1000. Values of 500 or less indicate possible problem with LNA/LNB or IFL cable connection.

IF signal ADE-BDE - Low AGC and Threshold values indicate possible DAC tuner card failure, an IFL cable connector problem or possible LNA/LNB failure.

Ped & Radio M&C - Continuous Comm Errors or System Errors that wont clear indicate (ADE BDE) possible failure of Rotary Joint, RF modems (Pedestal or Base) or IFL cable problem.

*Troubleshooting and Repair(cont)Antenna System

Isolate the problem

Determine where the problem is (or isnt) 1.Ask why the system is doing what it is doing and what might cause that problem 2.Use parts from the spare parts kits to substitute as required or directed

Diagnostics Tools 1.Use of remote commands & remote monitoring in the DAC-97 & DAC-2.2200 to assist in isolation of the faulty unit or component. 2.Use of computer diagnostic tests (PCDAC and DacRemP) to record functions to assist in isolation of the faulty unit or component.

Software Tools (PCDAC & DacRemP)

1.Remotely Monitor & Control - the antenna through the ACU. Can be used on Series 96, 97, and 06 series antennas. 2.Tests include diagnostic tests (for Series 96, 97, and 06 antennas ) and Dishscan setup and operation


PCDAC & DacRemP Chart Recording

Both programs provide diagnostic charts - These charts will record, or display, a strip chart recording of system performance. Azimuth, Elevation, Rel. Azimuth, Heading, Heading plus REL and Signal (AGC), are recorded once per second.

One full screen of recorder data is 2 mins. Only 4 of these values are displayed on laptop screen, but all are being recorded and all will be displayed opened in Microsoft Excel.

In normal operation Signal level should always remain high and steady, so a falling signal level would indicate a problem.

Azimuth & Elevation should stay at the same values (in short term view) requiring many hours to significantly change.

Azimuth equals Heading plus Relative, so (in the short term) as Heading goes UP Relative MUST go DOWN the same amount (equal and opposite to what Heading does).

Troubleshooting and Repair (cont)In this case, the DAC is Tracking a signal and there are no errors

Antenna Not Tracking

DAC Shows No Errors

Is DAC Tracking or Searching ?

NO

YES

Turn Tracking On

Searching

Tracking

NEXT PAGE

NEXT PAGE

DAC Is Searching

Are DAC & Threshold values within "Normal" Range ? (> 1400)

NO

DAC & THRSH values < 1000

Check RF Equipment for LNA or Other Alarms - Replace LNA as required

YES

Confirm LAT, LONG, and HDG Values are Correct . Adjust/Correct as Required and Re-Target Satellite

Does Antenna Find Satellite ?

Does Antenna Find Satellite ?

NO

YES

Confirm Ship's GYRO and GPS are Communicating with the DAC - Report Incident to HiSeasNet Cust Support

Confirm DAC Parameters are Correct - Can Antenna be Manually Pointed ?

YES

Check AZ & EL Trim ValuesAdjust as needed and Re-Target Does Antenna Find Satellite ?

NO

YES

Record New AZ & EL Trim Values & Report incident to HiSeasNet Cust Support

Contact HiSeasNet Cust Support

DAC Is Tracking

Does Comtech Modem show RX Lock ?

NO

YES

Antenna Possibly Tracking Adjacent Satellite Record AZ, EL, AGC, & THRSH values and Re-Target satellite

Is Comtech Modem set to Transmit and is Modem Transmit Light On ?

YES

Check Codan RF Equipment for Error Condition

ConTact HiSeasNet Customer Support

Replace RF Equipment as Directed (If Spares are Available)

Does Antenna Find Correct Satellite ?

YES

Record AZ & EL Values

Contact HiSeasNet Customer Support

NO

Antenna Returns to Previous AZ & EL Values and begins Tracking No Modem RX Lock

Turn Tracking OFF - Manually Peak Antenna on Correct Satellite(Max Eb/No and AGC )

Compare AZ & EL Values and Adjust AZ & EL Trim Values

Re-Target Satellite Using Adjusted AZ & EL Trim Values Does Antenna Find Satellite ?

NO

YES


Record New AZ & EL Trim Values and Report Incident to HiSeasNet Customer Support

DAC No Errors

Troubleshooting and Repair (cont)In this case the DAC is not tracking and there are GPS and Gyrocompass errors


DAC Reports GPS / GYROCOMPASS Errors

Confirm that Ship's GPS & Gyrocompass Systems are Operational - Repair as Necessary

Confirm that DAC is Receiving Correct LAT, LONG, and HDG Information

Clear Errors on DAC. Do Errors Remain Clear ?

YES

Re-Target SatelliteDoes Antenna Locate Satellite ?

YES

Repport Incident to HiSeasNet Customer Support

NO

If Antenna Doesn't Find Satellite Refer to Troubleshooting Section "DAC - No Errors"


NO

Replace DAC with Spare (if available) and Contact HiSeasNet Customer Support

GPS and Gyrocompass errors

Troubleshooting and Repair (cont)In this case the DAC shows Comm & Dishscan errors

AntennaNot Tracking

DAC Reports Communications / Dishscan Errors

Check / Confirm Correct DAC Parameter Settings and then Clear DAC Errors

Do errors clear ?

YES

Check Antenna for A/C Power . Check IFL Cables for Good Contact

NO

Re-Initialize AntennaDoes Antenna Complete Initialization Correctly ?

NO

Note Type of Failure & Contact HiSeasNet Customer Support

YES

Can DAC Errors Now Be Cleared ?

NO

Possible Rotary Joint or RF Modem FailureContact HiSeasNet Customer Support

YES

Re-Target SatelliteDoes Antenna Find Satellite Correctly ?

NO

YES

Report Incident to HiSeasNet Customer Support

Re-Target SatelliteDoes Antenna Find satellite Correctly ?

NO

Possible PCU or System Failure. Contact HiSeasNet Customer Support

COMMUNICATIONS & DISHSCAN ERRORS

Troubleshooting and Repair (cont)In this case the DAC is showing Pedestal errors


DAC Reports Pedestal Errors

Decode Errors Using RemDacP Software or DAC Front Panel

Record Errors & then Clear All Errors. Do Errors Clear or return ?

Check Antenna pedestal for A/C Power, Balance, Loose or Binding Cables, & then Re-Initialize Antenna

Observe Initialization Sequence Does Process Complete correctly ?

YES

Can DAC Errors Now Be Cleared ?

NO


YES

Proceed with Re-Target of the Satellite

If Antenna Doesn't Find SatelliteRefer to Troubleshooting Section "DAC - No Errors"


NO

Re-Balance Antenna as needed & then Initialize again. Does Sequence now Complete Correctly ?

NO


PEDESTAL ERRORS

Lab Exercises

*

Documents

HiSeasNet Training Seatel Stabilized Antennas Series 9797, 4996, 4006, & 6006