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DSC Redux

Electronics February 2001
By Tim Clark

DSC Redux
Two more VHFs featuring a system that could some day save your life.
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In last month's electronics column, an overview of the new generation of DSC-equipped VHF radios, we inadvertently left out two models. This month we're covering them and briefly recapping DSC because we strongly believe the technology significantly enhances boating safety and convenience.

For decades, radios have added immeasurable practical advantages and security to boating. While there have been countless incremental refinements in the technology over the years, the introduction of DSC represents a giant step. Briefly stated, DSC condenses the numerous essential elements required in a distress call into one push of a button. Moreover, the signals transmitted by DSC are digital. That means that when your DSC radio is interfaced with your GPS, you can send--in a single electronic message--not only an alert that your boat is in trouble, but also her position, the time and date of the transmission, and even crucial identifying information about your vessel, via her Maritime Mobile Service Identity (MMSI) number, which the FCC assigns you when you register your radio. All this is broadcast automatically and continuously once you hit the button and can be picked up by the Coast Guard (national DSC transmission coverage is nearly complete) and any DSC-equipped radio on vessels within range. Obviously, compared to a conventional radio MAYDAY, during which stress can lead to grave errors and the time available for the call may be severely limited, a DSC distress signal is far superior.

But DSC functions include more than this feature, which you're admittedly unlikely to ever need. There's also the ability to route messages directly and exclusively to another vessel (which you identify by entering its MMSI number), so the days of broadcasting conversations far and wide that you'd prefer to keep quiet are over. Onto a hot fishing spot and want to let a friend know its location without attracting the rest of the fleet? Just send over your MMSI number, your boat name, and a channel you want him to respond on, and you and your friend can talk over the fine points in total privacy by using the radio's scrambler option. Feeling especially magnanimous? You can notify every DSC-equipped radio in range simultaneously.

Standard Horizon's Spectrum VHF marine radio boasts all these abilities and more. Its DSC Standby Mode is like a VHF version of a telephone answering machine and lets the Spectrum receive and store unanswered calls in a call-waiting directory that you can review at any time.

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