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Installing a satcom

Jan 1, 2003

Satellite communications technology continues to improve. New generations of geostationary communications satellites dramatically decrease the size requirements of dish antennas, and new clusters of low-earth-orbit satellites may soon lead to a communications capability for which no installed equipment is required. Low-earth-orbit satellites may soon be accessed with handheld communicators that look and feel quite similar to present-day cellular phones.

What about installing these units? Can you do it yourself? If you are looking to save about $1,000 on your shipboard satellite phone system, you can legally install your own ship station satcom phone and maybe get it up and running without having to call that $75-per-hour technician to come on board and do the magic that is spelled out clearly in your installation manual. It is important to remember, however, that an installation mistake could void your warranty. So proceed carefully.

Parabolic reflectors (dish antennas) and microwave strip-line antennas are employed to "focus" enough of a low-level signal to provide an uninterrupted path for data or voice communications. But unlike a direct-broadcast satellite dish system, a marine satellite phone transmits as well as receives, so there are additional safety concerns about where the satellite antenna is mounted to ensure that everyone on board stays out of line with the outgoing signal. For example, your radar operates up near 9,900 MHz, and the same precautions you take against getting accidentally zapped with radar waves also apply to the satellite phone system.

Satellite phone frequencies are twice as high as a cellular phone, and ten times as high as a marine VHF. The satellite phone microwave band is also located within 100 MHz of the civilian global positioning system (GPS) band.

Slow-speed, data-only satellite messaging can be accomplished without the need of a dish antenna. Inmarsat C is a good example of a microwave satellite system that does not need a stabilized parabolic reflector.

If you are planning on voyaging the world, consider the Inmarsat mini-M service. Inmarsat is an international consortium of 79 member countries that pioneered in the field of mobile satellite communications, and is the world's largest provider. The Inmarsat mini-M network is based on four powerful, new, state-of-the-art satellite spot-beams that cover almost all of the world's popular voyaging regions, except for a couple of holes in the South Atlantic and Southern Ocean.

Service providers

Inmarsat sells large blocks of minutes to its partner companies, which tend to be very large communications companies like PTT Telcom, Station 12, Comsat, British Telecom, Telstra, Singapore Telecom, and other biggies. These companies then sell blocks of minutes to other value-added resellers like ATandT, IDB, Stratus Mobile Networks, MCN, Seven Seas, and many others. You can buy service either from one of the larger partners or from the value-added resellers.

If you don't plan to sail the world but wish to cruise coastal North America, out to 200 miles, including the Caribbean, Panama, Hawaii, and Alaska, you may wish to consider American Mobile Satellite Corporation (AMSC) regional service providing digital voice, fax, data, and voice-dispatch services. Instead of paying a slightly higher price for voice and data communications throughout the world, you pay a lower price for voice and data communications throughout the voyaging regions of North America. The directional antenna systems are almost identical, and one manufacturer, KVH, recently announced a "convertible" AMSC/Inmarsat phone system that you can install yourself for either AMSC service or, when you're prepared to sail the world, Inmarsat mini-M service. Conversely, if you have been overseas using Inmarsat mini-M, the new KVH phone system antenna lets you switch over to AMSC regional coverage without about 50% savings on calling rates.

If you are not interested in voice messaging, you may want to consider installing your own Inmarsat-C unit for two-way store-and-forward data, fax, and e-mail communications. The Inmarsat-C system is the easiest to install because the antennaabout the size of a footballdoes not require internal stabilization, and it can go just about anywhere because of its small size. As your voyaging requirements change, you can upgrade an Inmarsat-C system to include distress alerting and automatic position sending.

If you're going to be jumping around from one boat to another, there is no installation necessary with the new low-earth-orbit data communicators, as well as the low-earth-orbit voice phone systems that will soon be on the air. You could also bring along your mini-M briefcase phone, jump on shore, aim the antenna, and have capability for voice or data communications without any installation at all.

Mini-M and AMSC

"If you can install your own radar, you can easily get mini-M or AMSC satellite phones on board and working," said Don Melcher of HF Radio On Board/Complete Cruising Solutions in Alameda, Calif. "But let the equipment provider know ahead of time that you plan to put in the system yourself so they can provide you with all of the necessary installation manuals and some helpful suggestions for a trouble-free activation." He regularly sells to "do-it-yourself" mariners who successfully install the Westinghouse Wavetalk lightweight satellite system aboard sailboats and power boats.

Satellite phone equipment providers and seasoned installers all agree that connecting the system directly to a battery is an important consideration. "Wiring the satellite system into a nav station circuit breaker is really going to cause you some headaches," said Bill Alber, a marine electronics installer in the Sacramento, Calif., area. "Switching off the satellite system right in the middle of a call could not only require a complete system re-boot, but it might cause a voltage spike that could be lethal to the sensitive transmitting and receiving electronics." KVH Industries agrees: "We strongly recommend that you wire our Tracphone products directly to an uninterrupted 12-volt source, such as directly to your batteries, for the best conditioned voltage." The KVH Tracphones operate on DC power levels from 10 volts to 32 volts, but it's not the variations in voltage that cause the problems, but rather voltage spikes. Aboard commercial boats, KVH even recommends that an isolation power conditioner, such as a DC/DC converter, be installed where the power source is erratic or noisy.

If your power run is going to be more than 20 feet, red and black duplex marine-grade no. 8 gauge wires would minimize voltage drop and provide good waterproof integrity should the wires get wet. Ancor marine-grade duplex DC cables are available at most marine electronics stores. Most satellite phones do not include the DC wiring, so keep this in mind before you open up the box and don't find a pair of red and black wires.

The actual RF (radio frequency) transceiver may be mounted in almost any position clear of salt spray or water that might leak in through a porthole. Most AMSC and Inmarsat mini-M transceivers have massive heat sinks to keep them running cool. So don't bury them too far out of the waysome transceivers may require access for inserting the SIM (subscriber identification module) billing card for multiple users. If an RF satellite transceiver is hard to access, getting the SIM card plugged in could be a big chore. Also, be sure to allow enough clearance so you can plug in the cables without kinking them or putting a strain on the actual cable connectors.

After the transceiver is mounted, some units require a slightly smaller, secondary, sealed electronics package to go into the same mounting area. This unit is sometimes called the antenna electronics unit, or the antenna interface adapter. If you got one as part of your AMSC package, it also needs to go down below, out of the weather. The antenna electronics unit normally does not require any adjustment or card insertion, so it can go out of the way and out of sight. If you see heat sinks on itextruded aluminum finsbe sure to give it a little breathing room.

Hook up cables ahead of time

"I always hook up my cables well ahead of time before burying the electronics," said Tom Mackie, sales engineer for Trimble Navigation. "This way I can easily see my pin connections, and I can double-check that the cable plugs go in smoothly without any pin getting pushed out of place." The Trimble Inmarsat-C satellite computer system has fewer little "black boxes" than AMSC or mini-M stabilized satcom equipment.

"The most important thing is to carefully match up the proper cable with the right connectionand on most satellite systems, each jack has a different pin configuration, so you normally cannot plug the wrong plug into a jack," said Bill Alber.

With the Westinghouse Wavetalk, all of the cables are already made up, so you can't make a mistake on how things get wired in, according to Don Melcher.

Where do you plan to do your voice phone calling and run your computer and fax machine? You want to ensure that your computer and fax printer are in an absolutely bone-dry area of your ship, and that there is absolutely no way any moisture can get into this very sensitive equipment.

The AMSC SKYCELL system has a ready-made 16-foot cable that goes between the satellite transceiver and a junction box. The junction box then has a ready-made cable assembly that goes between the handset/cradle assembly and the junction box, plus additional ports for adding additional handsets or a microphone and speaker set-up for hands-free phoning home or conference calls.

On the O'Gara satellite Boatfone, the handset cradle doubles as the distribution point for your e-mail computer system and the fax machine. The KVH Tracphone has no intermediate interface adapter to the main transceiver; the cradle carries all the connections for external microphone, fax machine, dB-9 serial port, and a long, coiled-cord, tethered handset for private communicating. An optional interface box is available for a neat cable job.

"Most telephone handsets and cradles are relatively weatherproof and should survive the marine environment well. But they are not intended for on-deck use, and direct water to them would probably cause a malfunction," said Alber. So place the handset wherever you will probably do most of your voice communication. Keep in mind where it goes in reference to the rest of the crew, who may be sleeping when you want to phone home after midnight watch.

In a trend that makes satcom more attractive to smaller boats, antenna units with an enclosed, stabilized antenna system are getting lighter and more compact. The KVH Tracphone 50 antenna unit weighs 30 pounds and measures 19 inches in diameter. The company's brand-new Tracphone 25 antenna unit weighs 11 pounds and measures 10 inches in diameter. The Westinghouse Wavetalk antenna weighs 2.2 pounds and is a 6.5 inch oval.

Mountantennaintheclear

The antenna unit cannot be mounted belowdecks. It should also not be mounted back aft on the stern rail. It must be mounted up and in the clear, in the same way you would mount a small radar antenna. And since the satellite antenna system for phone and data also transmits, you must ensure that no one stands in line with the antenna unit closer than three feet away. Actually, when compared with that small radar antenna up on the pedestal, the satellite phone system is much safer to stand close to than the radar. But radar only exposes you to radio frequency energy once every couple of seconds during rotation, whereas standing within a few inches of an energized satellite phone antenna could put you over the legal limit for microwave radiation.

Melcher recommends getting the satellite antenna up on a pole much like a radar. "But don't put the satellite antenna and the radar antenna in the same plane on the same pole, as this may cause interference," said Melcher. This advice is echoed by all of the satellite antenna manufacturers, tooput it above or below your radar, but not in the same plane. Vertically, they should be no closer than 10 feet apart.

The ideal antenna location gives an unobstructed line-of-sight view to the satellite in all directions around the vessel, according to KVH technical personnel. To minimize the effects of pitch and roll on the integrated sensor assembly, the pedestal should be located as close as possible to the vessel's center of gravity. KVH recommends putting the antenna system no higher than one-half the vessel's length and suggests positioning the antenna as close as practical to the vessel's fore-and-aft and athwartships centerlines. Fore-and-aft centering is preferred; athwartships positioning is less important, according to KVH. If the satellite antenna is to be mounted on the mast, separate the pedestal from the mast by a distance equal to at least four times the mast diameter. In other words, keep it at least three or four feet away from aluminum masts.

There is one additional consideration on these motorized tracking antennasnever allow them to be near ferrous metal objects. A hunk of metal may influence the fluxgate compass sensor, and this will affect satellite tracking accuracy. This is one additional reason why you want your satellite antenna up and away and clear of anything that might adversely influence its capability to stay locked on the incoming satellite signal.

Most satellite communications stabilized antenna systems will include a base plate assembly that is easily removed to allow you to secure the base plate into proper position before adding the rest of the antenna electronics.

"It's very important to ensure that the drain hole never gets blocked in the base plate assembly," said a marine electronics technician out of Miami, Fla. And if the base plate will be mounted directly to a flat surface, such as a cabin roof, be sure to make the cable connections before mounting. This is due to the fact that access to the cable channel will be impossible once the base plate is bolted down.

Your satellite antenna system may have one or two cables feeding it. On the KVH Tracphone 25 and 50 antenna units, two cable assemblies with pre-connected plugs feed the antenna unit from the belowdecks-mounted transceiver.

The Westinghouse Wavetalk has two antenna cables that you will need to hook up. "One cable is coaxial cable with pre-assembled connectors already on each end," said Melcher. "The other cable is a power and control line where the pins have already been connected but must be inserted in the proper openings in the plug assembly in order to complete the installation." This allows you to route the cable and the pre-soldered pins up through a small hole and then do the job of plugging the right pins into the right holes. Needless to say, you must really follow the instructions carefully.

Soldering a TNC connector

With some antenna installations, you will need to install a threaded N-connector (TNC) to finalize the coaxial cable assembly. If you've never soldered a TNC connector, you will probably want to bring aboard a specialist who can do the job for you. You could also take the cable into the specialist and let him or her wire up the coaxial cable connectors, but check beforehand that you have enough room to get the assembly belowdecks through your waterproof deck fitting.

Most marine electronics stores carry waterproof deck fittings that easily pass antenna cable connectors, yet can cinch down tightly on the actual cable so that no water can get in.

According to KVH, their Tracphone antenna systems terminate the RF cable ends with coaxial connectors to avoid the possibility of a faulty installation. The company recommends that the RF cable be left full length and that no attempt be made to replace or rewire the RF connectors. This will minimize some intense headaches in case a connector made up in the field should contain a short.

The KVH Tracphone 50 is large enough to contain its own fluxgate sensor, but the Tracphone 25 requires an external sensor. The sensor contains many color-coded wires, and they must be properly terminated to the supplied terminal strip. This is a tedious job, and one misplaced wire can cause the entire system to malfunction. The wires are not tinned, but are slightly twisted and will naturally flare under the binding screw. This is the way that KVH recommends connecting the sensor wires.

Placement of the KVH external sensor should be made as close as practical to the vessel's center of gravity. The sensor goes belowdecks and is not designed to be exposed to the weather. You can parallel the coaxial RF cable run with the sensor wire. KVH cautions users not to mount the sensor upside down and to make sure that the word "forward" is, indeed, facing forward.

The Tracphone 25 system has two cables going up to the antenna unitone for the external sensor, and the other the coaxial RF signal cable that also contains power and control information. Both of these units require that the wires be led up the mast from the bottom, since the connector at the bottom end is large and shouldn't be run down the mast. On the Tracphone 50, one cable is for power, and the other cable connects the RF signals and control data to the transceiver. The Tracphone 50 power requirements may be met with 14-gauge wire for runs under 50 feet and 12-gauge wire for runs between 50 and 75 feet. However, you might still want to go with the larger cable going to the belowdecks transceiver to provide a good solid voltage source, plus a direct, fused connection to the battery to minimize voltage spikes from the charging system.

The Inmarsat-C system supports two-way global messaging, telex, e-mail, test fax, and special service code operations via terminals that you can easily install yourself. Enhanced Inmarsat-C3 service with even smaller terminals is just coming on line, suitable for vessels operating along the coast.

Integral GPS receiver

The Inmarsat-C antenna is about the size of a football standing on end. Actually, a slightly larger high-capacity antenna system is available; either the larger antenna or the smaller one is easily user-installable. The Inmarsat-C antenna may also house a GPS sensor, too. Both the GPS antenna and the Inmarsat-C antenna are omnidirectional, right-hand-circular polarized.

"Since the antenna only weighs 4.5 pounds, it may be mounted anywhere, in the clear, without the need of a heavy support pole," said Tom Mackie, sales engineer for Trimble. "You would also take the same RF precautions as you would with other types of satellite antennas that transmit RF microwavesmake sure the antenna is not down low where on-deck personnel would get too close."

In other words, even though the antenna would go nicely on the stern rail, don't mount it there. Although it would probably work just fine on the rail down low, there is still the potential of RF exposure plus interference from a lot of crewmembers standing around it. Marine equipment companies like PYI, Inc., in Edmonds, Wash., and Edson International of New Bedford, Mass., markets radar and satellite phone mast platforms that are specifically designed to accept the base-mounting templates of modern satellite phone systems.

A single coaxial cable connects the antenna to the eight-pound transceiver mounted below. According to SEA, a unit of Datamarine International, in order to install its new SEASAT 3 Inmarsat-C system the installer has to supply his or her own coaxial cable. A built-in, eight-channel GPS receiver offers a new format for connection reporting that allows your travels to be monitored automatically by stations on shore.

The belowdecks Inmarsat-C transceiver is powered by a minimum of no. 12 wiring. This oversized wiring will decrease the chance of voltage drops and spikes when connected directly to a battery. The unit draws only about seven amps on transmit and less than one amp on receive, and just a fraction of an amp in the sleep mode.

You will need to do your own coaxial cable connector soldering when terminating both ends of the coaxial cable. Like all satellite units, the coaxial cable plug is not a common PL-259, but rather a type N connection that requires delicate soldering techniques.

The user's laptop computer ties into a dB-9F connector, and a standard parallel IEEE 1284 Centronics dB-25F connector is available on the transceiver for the hookup of a printer. There are also input and output dB-15F jacks for NMEA 0183 Version 2.1 language.

The Magellan World Phone, operating on microwave mini-M frequencies, simply requires a stable platform to get on the air. You go ashore, aim the briefcase-sized phone in the right direction, nudge it one way or the other to increase signal reception, adjust the angle of the briefcase antenna lid, and you are on the air for either voice, fax, or data.

Handheld satellite communicator

With the new Magellan GSC Data Communicator, which uses the low-earth-orbit Orbcomm system of satellites, you pull up the yard-long telescopic whip, hold your position with the whip at a 45° angle, and see whether or not you have satellites in view. If you do, hit the send button. If you don't, you can leave the unit turned on; when it finally senses the satellite, your data message will be sent. The Magellan GSC 100 operates on frequencies just below the marine VHF band, and the power level is so low that a few inches of separation between the telescopic whip and your body is all that is required. It puts out less power than a six-watt VHF handheld.

"As long as our VHF satellite global data and messaging transceiver has the antenna fully extended, and the set is operated out in the open, there is no specific requirement to hold the antenna absolutely steady," said David Salwen, product manager for Orbcomm. "Our unit can easily reach any of the low-earth-orbit Orbcomm satellites when they come up over the horizon, so there is no major need to fuss around with how the unit is held." I have operated the new Magellan GSC 100, and it easily gets through when satellites are in view.

I also had a chance to get in on some Iridium satellite tests with Bill Eichenberger, Iridium North America, channel support specialist. The Motorola Iridium portable telephone combines the global roaming convenience of a satellite phone with the added functionality of terrestrial cellular capability. You simply extend the extra-long satellite antenna when you are far out at sea. You can then access the new constellation of low-earth-orbit Iridium satellites.

So going satellite with your own installation is relatively straightforward, and no more difficult to install than a fixed-mount GPS tied into your laptop for chart plotting, or installing a small LCD radar.

"If the mariner who self-installs equipment purchases the unit through a dealer who brings in the equipment pre-registered, it will make the paperwork flow smoothly," said Ken Englert of Maritime Communications in Marina Del Rey, Calif. "We get our customer's equipment through Marine SAT as a turn-key system, and we like this plan better than going with the equipment supplier." Don Melcher echoes these same sentiments: "When you buy the system through me, I can handle all of the licensing as well as registration for an almost immediate turn-on. All the customers need to do is to supply their credit card billing information to the service provider."

However, give yourself some time to get the commissioning completed properly. "If you are starting a global voyage and purchasing Inmarsat equipment, don't wait until the last minute and expect to get the satcom installed and be on your way," said Carl Sederquist of Quest Telecom of Ellsworth, Maine.

Several marine electronics dealers report that Marine SAT has also come up with a way to add facsimile capabilities to the Wavetalk system, too, for an additional $1,000. They report that Westinghouse (the manufacturer of the equipment) as well as AMSC (the satellite provider) indicated fax might be a problembut down at the service provider level, they made it happen, and the dealers were given the information on how to add conventional fax to the on-board system.

"I strongly recommend mariners who plan to install their own equipment stay with a local authorized satellite phone dealer and let that dealer provide all of the hardware and the commissioning and licensing expertise for a turn-key system," said Mark Upson, a marine electronics store owner installer for GandA Electronics in Newport Beach, Calif. "The dealer works for you, and will work at break-even prices to get the system up and running aboard the boat because the dealer ultimately gets a small percentage of your air time as a commission. If mariners try to go 'direct' with the equipment, bypassing the dealer, they will be faced with some big hurdles when it comes to getting the equipment commissioned, properly set to the right satellite, and put on the air properly."

"We concur that authorized satellite phone dealers should be involved in the final commissioning of the equipment," said Jim White of Magellan. He points out that the dealer needs to inform the mariner about legal issues of when and where certain satellite phone equipment may be used. For instance, the Magellan World Phone is intended for international open-water use with the accessory tracking antenna system. It is presently not legal to use World Phone on shore in the U.S. due to "exclusive agreements" with AMSC. This is where your dealer can help you better understand the legal aspects of calling home from anywhere.

The same dealer can also analyze your communication requirements and set you up with the right satellite phone system that will offer you the most advantages for the least amount of monthly sign-up and air usage fees. Although most dealers agree that you could probably save more than $1,000 by installing the hardware yourself, they caution their customers to stick only to mounting and wire routing. Run the cables, install the antenna, mount the transceiver equipment, and then bring in an authorized dealer to finalize the cable hookup and commissioning. n

Gordon West is a freelance writer who specializes in electronics and communications. He is also the founder of Gordon West's Radio School in Costa Mesa, Calif., 714-549-5000.


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