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Linking to the heavens from the seaLindsay McRoryJanuary 20, 1996 The arrival of our MSAT satellite-based communications system came like a belated present from Santa. I managed to find the time to install it and run it through its paces. The system consists of three major components: a base unit and handset, an antenna amplifier, and the antenna. I was surprised at the high quality, rugged construction. The antenna is unusual. The short, fat carbon fiber rod looks more like a Jedi light saber than an antenna. The adjustable base is rotated until your present location is locked into the satellite, which is in fixed orbit overhead. The cable length from the antenna amplifier is fixed at 10 feet. This cannot be extended because of signal loss that would be incurred when operating at high frequencies (1,525 to 1,660 MHz). Getting the antenna high is not a concern, but getting it out of the way of the running rigging (and running kids) is a big concern. Ten feet is not a lot to play with on a boat. The only option I have is to mount it parallel to a stanchion. Another disappointment is how directionally sensitive the antenna is. It has to remain vertical. If the boat is heeled 15 degrees, the unit will not work. A "bicycle helmet" style marine antenna will be available in a month or so. This antenna is not supposed to be as sensitive to angle or motion. We will order one of these and use the rod as a spare. The base station connects to the handset and the antenna tuner. It has a RJ11 fax connector as well as a separate DB25 computer connector for its built-in Hayes compatible modem.
Data communications works the same as any Hayes compatible modem. Sessions have been error-free and more stable than data over cellular telephone systems. The temporary downside--reportedly a short-term one--is a current bandwidth constraint of 2,400 bps. A mere five years ago, 2,400 bps was plenty to get around. Now it is close to unusable. On June 1 the rate will be increased to 4,800 bps, which is still slow but twice as fast as the current performance. I am not sure if future speed increases are planned. This is clearly the dawn of a new era in global communications. Several other new initiatives loom over the horizon: the Iridium project, ORBCOMM, and a new system from INMARSAT, to name a few. For the voyaging sailor, keeping plugged in will affect all aspects of cruising.
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The system takes about two minutes to power up, run through
its diagnostics and find a satellite channel. Voice communications are
very clear, although there is a slight warble present if you listen
carefully. Odd is a quarter-second delay between the time you talk and the
time it's received. You almost want to say "over" after you end a
sentence. After a few minutes of conversation you learn to adapt.
