There's something to be said for a company that follows the adage of doing one thing and doing it right. Icom is a good example. The company has enjoyed success by concentrating its research-and-development dollars on one category: marine radios. With the new IC-M602, the company is focusing on one of the most important elements of a marine radio: safety.
Though the VHF/DSC radios introduced about eight years ago provided digital selective calling (DSC) for emergency use, their value for routine DSC functions was limited. This is where the IC-M602 has a leg up. It performs well in emergency-signaling situations and conveniently carries out more routine DSC tasks, adding up to a radio that should serve well as the primary one aboard yachts of all sizes.
The IC-M602 has a second receiver that is permanently tuned to channel 70, accounting for much of its superior DSC performance (and a substantial part of its cost). The IC-M602 receives DSC calls transmitted on channel 70 whether the transmitter is in use, or whether the primary receiver is receiving voice communication, weather information or scanning for traffic. As with all DSC radios, an incoming distress call is announced by an unmistakable alarm that continues for as long as two minutes, or until a control key is pressed. Then, "received distress appears on the LCD screen, and the main receiver automatically switches to channel 16 to monitor voice communication related to the mayday call. In a 20-position distress-message memory, the IC-M602 stores the Maritime Mobile Service Identity (MMSI) number of each transmitting vessel, as well as its position and the time of the call. This is handy if you must relay a call to a shore station unresponsive to the original distress call. In addition, the radio automatically acknowledges and stores up to 20 routine communication DSC calls. It's not quite voice mail, but you will know what's happened if you step away from the radio.
The IC-M602 has large, logically placed controls and a clearly marked, guarded Distress button, which should make emergency use intuitive for even a novice. Lifting the guard and pressing Distress for five seconds transmits a mayday call followed by five short beeps and a prolonged beep, indicating the call has been transmitted. A message confirming transmission appears on the LCD screen. Once initiated, distress calls automatically repeat every three-and-a-half to four-and-a-half minutes until acknowledged. From a 12-item list in the "distress setting menu, users can cite reasons for distress calls. Five seconds after transmission, as it does when receiving distress calls, the IC-M602 switches automatically to channel 16, so it can receive voice communication from the responding station.
It is worth noting that the U.S. Coast Guard's nationwide communication system, Rescue 21, begins operation this year. In effect, Rescue 21 will serve as the maritime equivalent to the land-based 911 emergency response system. Though Rescue 21 will work with standard VHF radios, yachtsmen using DSC radios interfaced with GPS systems, such as the IC-M602, will reap the full benefit. The IC-M602 provides accurate coordinates of a distressed vessel's position and allows for clear, uninterrupted communication with responders.
The IC-M602's DSC capabilities, however, go beyond sending and receiving distress calls. For instance, instead of the sometimes-difficult process of contacting another vessel on channel 9 or 16, you can send an individual DSC call by specifying the vessel's MMSI number. The receiving radio will announce the incoming call and should capture the attention of even the most oblivious watchstander. The receiving radio will identify your vessel and can automatically switch to the communication channel you have designated. The radio's memory stores up to 100 addresses (or MMSI numbers) of up to 10 characters each.
An "all ships call alerts all vessels within radio range. We found this feature useful when encountering ships and other yachts on the high seas. After an "all ships call has been transmitted, "received all ships appears on the receiving end. Receiving radios will then automatically switch their main receivers to channel 16 for voice communication. On your end, the digital response sent automatically from a called vessel will include its MMSI number and GPS position. The IC-M602 can use a pre-selected group-calling number to contact all the vessels in a flotilla. You may also send a position-request signal to prompt a receiving radio for its latitude and longitude. The radio can be programmed to respond to a such a request by silently sending position information to the inquiring station.
Though many mariners believe a transmitter is the most critical and costly part of a VHF radio, the receiver is what determines its communication performance and value. A receiver in a high-quality radio should provide clear audio, even in congested areas where high-power interference can degrade or prevent clear reception. The IC-M602's two receivers have first-rate sensitivity and selectivity and should reject most unwanted interference. The three-level sensitivity control for the main receiver is useful for ensuring good communication in areas of severe radio interference.
The IC-M602 includes all the usual bells and whistles: automatic weather alert, dual- and tri-watch (repetitive scanning of two or three channels), and priority and normal sequential scanning. The LCD shows the function-calling, telephone, intership, and so on-of the selected channel and its number. The position display information from the yacht's GPS provides assurance that this critical data link is operating properly.
Unlike radios with permanently connected microphone cables, the IC-M602 comes with an HM-136 microphone that plugs into the front panel, allowing for use of an extension cable. Two HM-127 remote-control microphones can be plugged into the radio's rear panel, allowing the radio to be operated from up to three locations. This is a great feature if your yacht has more than one helm, as well as a remote station. Furthermore, the remote-control microphones can work with the main microphone as intercom stations.
The 5-watt amplifier provides all the speaker audio you could ever want. A separate 22-watt amplifier powers a hailer speaker. The hailer also functions as a foghorn, automatically sounding any of four signals mandated for use in conditions of limited visibility: underway, stop, sail and tow. The foghorn's frequency can be selected in the range of 200 to 850 Hz. (Under international rules, vessels shorter than 75 meters must use a frequency between 250 and 700 Hz.)
Finally, for fishermen who want to tell their buddies where the fish are biting without alerting the rest of the herd, there is an optional UT-112, 32-code voice scrambler. Price: $549.
Contact: Icom America, Inc., (425) 454-8155; www.icomamerica.com.
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