Making a distress call NOTE: There is no official VHF DSC shore infrastructure in Australia. Vessels fitting VHF DSC equipment should realise that this equipment can only be used for vessel - to - vessel alerting in the Australian region. There is no official shore-based infrastructure but there are a number of volunteer marine rescue (VMR) stations that have installed VHF DSC and a check with your local VMR should be made.
Table of Contents Table of Contents Making a DSC DISTRESS Call ..................2 Making a voice distress call ..................2 Table of Contents ..................4 (this page) Introduction ........................6 Features........................6 Manual overview ......................6 Conventions ......................6 Terms used in this manual ..................7 Getting Started ........................8 What's included ........................
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Table of Contents (Cont'd) Enabling automatic test call reply ................36 Requesting another station's position (POS Request) ..........36 Receiving a position request (Position Reply) ............37 Enabling automatic position reply ................37 Sending your own position (Position Send) ..............38 Putting the radio into standby..................38 Disabling automatic channel switching ...............39 Renaming Channels .....................40 Installing the Hardware ....................41...
Introduction Introduction Features • Watertight Radio Housing: Meets the worldwide JIS6 water resistant specification means it is able to withstand powerful water jets without damage. • Rugged Waterproof Speaker Microphone: With Channel Select, One-Touch 16/9 and Triple Watch Select Keys. Meets the worldwide JIS7 waterproof specifications;...
Introduction Table 1 - Terms used in the manual Digital Selective Calling. A VHF radio standard for communicating among boats and sending automated distress calls. Global Positioning System NMEA National Marine Electronics Association. The organization that governs standards for electronic equipment used on boats.
Getting Started Getting Started What's included UM425 VHF VHF DSC TRANSCEIVER 1 Watt Memory Scanning Channels 01,03,05,06,07,08 UM425 Radio DC Power Cable Accessory Cable Mounting Bracket and knobs Mounting Hardware Spare Fuse 250V 6A Microphone Hanger and Mounting Hardware...
Getting Started Parts of the radio Antenna Accessory Heat sink connector connector (SO238) ANTENNA 13.8V DC Power connector Table 2 - Rear panel connector functions Connector Connects to For details, see Antenna connector External VHF antenna with Connecting the radio, a male PL259 (SO238) page 44.
Getting Started Button Press to... Press and hold to... Change the transmit power (see 1/25W page 20). Display the radio menu. Use the public address MENU-PA (PA) function. Start scanning the channels saved Save a channel into SCAN-MEM in memory. memory or remove a channel from memory.
How It Works Turning on the radio Turn the knob clockwise to turn on the radio. As it powers on, VOLUME-PWR the radio displays the user MMSI number; if there is no MMSI set, the radio displays MMSI not entered. When it powers on, the radio selects the last channel used.
How It Works In addition to the two main operation modes, the UM425 also provides two differ- ent “watch” modes which you can activate during any of the two basic modes. In the watch modes, the radio briefly checks for activity on a specific channel, then returns to its previous mode.
How It Works Table 5 - Normal mode status messages Message Meaning GPS Data OK The radio is receiving valid GPS data. Check GPS The radio is not receiving valid GPS data: check the GPS status screen and the GPS connection. Input Position The radio has been unable to receive valid GPS data for at least four hours;...
How It Works Normal mode with Triple and Dual Watch If you activate Triple Watch while operating in normal mode, the radio checks channels 16 and 9 every two seconds; with Dual Watch turned on, the radio only checks channel 16. The radio will not check channels 16 or 9 while you are actively transmitting;...
How It Works Scan mode You can save channels into memory and then use scan mode to monitor those channels. When the radio detects a signal on a channel, it pauses on that channel as long as the signal is received; when the transmission stops, the radio will continue scanning.
How It Works • To remove a channel from memory, set the radio to that channel, then press and hold the button for two seconds. Memory will no SCAN-MEM longer show on the display. • To activate scan mode, press the button.
Using Your Radio Using Your Radio To display the radio menu, press the button. The menu has the MENU-PA following options: MENU Individual DSC Call SELECT Group All Ships POS Request Position Send Test Directory Standby Receive Log Exit Setup USA/CAN/INT* SELECT Dual/TriWatch...
Using Your Radio • The currently selected item is highlighted in reversed out text. ▲ • Press the button on the radio or the button on the CHANNEL UP microphone to move up a line in the menu; if you are at the top line in the menu, the cursor jumps to the bottom of the menu.
Using Your Radio While listening to a channel, adjust the knob until the noise is SQUELCH filtered out and you can only hear the transmission. If you switch to a channel with a lot of noise or with a weak transmission, you may need to adjust the squelch level again.
Using Your Radio NOTE: By default, when you change to channel 16, the radio automatically boosts the power to 25 Watts. Be sure to change the power back to 1 Watt if you are not making an emergency transmission. Some channels limit the power of transmission to 1 Watt so that there is less interference between boaters attempting to use the channel at the same time.
Using Your Radio Changing display and sound options Contrast The UM425 display has 10 levels of contrast. To adjust the contrast, press while the radio is idle. Select System and then Contrast. Use MENU-PA buttons to change the contrast to your CHANNEL UP CHANNEL DOWN desired level then press the...
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Using Your Radio Display the menu and choose the Setup sub-menu. Select GPS Setup and then choose Position Set. The cursor highlights the hour. Use the CHANNEL UP CHANNEL buttons to set the displayed hours to match coordinated DOWN universal time (UTC, also call Greenwich Mean Time and Zulu Time). When the display matches UTC time, press the button.
Using Digital Selective Calling (DSC) Features Using Digital Selective Calling (DSC) Features What is DSC? Digital Selective Calling or DSC is a standard that allows you to call other stations using their unique identification code (the Maritime Mobile Service Identity or MMSI number), just like you would call a phone number. To call another station, just enter that station’s MMSI number and choose the voice channel you want to talk on.
Using Digital Selective Calling (DSC) Features Getting an MMSI number In order to use DSC features, you must be assigned an MMSI number and program that number into your radio. There are two kinds of MMSI numbers: individual numbers for use by single boats and group numbers for use by fleets, boating organizations, event coordinators, etc.
Using Digital Selective Calling (DSC) Features Use the buttons to change the first of CHANNEL UP CHANNEL DOWN the nine digits; the button increases the number and the CHANNEL UP button decreases the number. CHANNEL DOWN When the first digit is correct, press the button.
Using Digital Selective Calling (DSC) Features When the ninth digit is correct, press the button. The radio SELECT displays the new MMSI number and asks you to confirm. To save this MMSI number, select Yes. To cancel this MMSI number, select No.
Using Digital Selective Calling (DSC) Features Table 6 - Character and text entry order button button CHANNEL UP CHANNEL DOWN Capital letters (A through Z) One blank space Lower-case letters (a through z) Numbers (0 through 9) Punctuation (/ ‘ + -) Punctuation (/ ‘...
Using Digital Selective Calling (DSC) Features Making DSC Calls There are essentially four different types of DSC voice calls: Call type What it does When to use it Distress Alerts all stations that you need In an emergency only. assistance and sends them your current position.
Using Digital Selective Calling (DSC) Features Suppose you are coordinating safety for a sailboat race. Before the race starts, you instruct all the racers to enter your group MMSI number into their radios. During the race: • Throughout the race, you use group calling to update the racers on the time, race status, and any course corrections.
Using Digital Selective Calling (DSC) Features • When the other station accepts the call, both radios switch to the se- lected response channel for voice transmission. • If the other station cannot respond on the channel you selected, the radio displays Not support CH. Calling a particular group of stations (Group Call) Group calling calls all the stations that share your group MMSI.
Using Digital Selective Calling (DSC) Features Making an automatic distress call If you have programmed your MMSI number, the UM425 can transmit an automated distress call with your current location and nature of the distress. The radio then monitors the channel 16 for a response and repeats the distress call every few minutes until it receives an acknowledgement.
Using Digital Selective Calling (DSC) Features Receiving a DSC call If your radio receives an individual DSC call from another station, it sounds an incoming call tone and displays the name or MMSI number of the station calling you. To respond to the call, select Send: Able-Comply; the radio sends an acknowledgement and automatically switches to the designated response channel.
Using Digital Selective Calling (DSC) Features Making Test Calls (Test) You can use the test call feature to make sure your radio is working and configured correctly. To avoid overloading coastal receiving stations, you should limit test calls to these stations to once a week. NOTE: Many coastal stations have specific frequencies and MMSI numbers you should use for making test calls.
Using Digital Selective Calling (DSC) Features When the other station acknowledges Test the test call, the radio displays an ac- Acknowledged knowledgement screen. 123456789 Completed Receiving a test call Test When another station sends you a test call, 123456789 the radio displays the test request screen: Reply To acknowledge the test call, select Reply Cancel...
Using Digital Selective Calling (DSC) Features Press the button to display the menu. MENU-PA Choose the DSC Call sub-menu, then select POS Request. The radio displays the names listed in your directory; use CHANNEL UP buttons to highlight the directory entry you want to CHANNEL DOWN contact and press the button.
Using Digital Selective Calling (DSC) Features Press the button to display the menu. MENU-PA Select Setup and then POS Reply. Highlight Auto and press the button. The radio will SELECT automatically transmit your position when it receives a position request. To disable automatic position reply, repeat the steps above and select Manual.
Using Digital Selective Calling (DSC) Features 1 Watt MENU DSC Call Memory SELECT Standby DSC Standby SELECT Unattended Display the menu and choose the DSC Call sub-menu. Select Standby to place your radio in standby mode. The radio displays the standby screen, above. To cancel standby and return to the mode your radio was in, press any button.
Renaming Channels Renaming Channels If you discover that a marine radio channel has a different common name in your local area, you can change the name of that channel to make it easier for you to use (see the channel list on page 57 for the default channel names).
Installing the Hardware Installing the Hardware Mounting the radio The UM425 can sit at any angle in the mounting bracket so it can easily accommodate the best location. First, determine the best place to mount the radio. For optimum performance, find a location that can: •...
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Installing the Hardware Position the radio into the desired location. Mark the edges of the bracket on the mounting surface. Remove the mounting bracket drill template from the back of the manual, and use the template to mark the drill holes on the mounting surface.
Installing the Hardware Connecting the radio To operate correctly, your UM425 requires two electrical connections: • providing it with power from the boat’s electrical system • connecting a VHF-FM marine antenna to the antenna connector Power supply requirements VHF antenna requirements Nominal 13.8 VDC power supply with Male PL-259 connector a negative ground (10.8 VDC to 15.6...
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Installing the Hardware Connect the BLACK wire of the included power cable to the NEGATIVE (-) side of your power source. Connect the RED wire of the included power cable to the POSITIVE (+) side of your power source. power cable to the power connector on the back of the Connect the UM425.
Installing the Hardware Connecting accessories Connecting to a GPS receiver If you connect the radio to a GPS receiver, the radio can automatically transmit your current position during an automated distress call or during a normal DSC call. The UM425 supports a standard NMEA0183 input from a GPS receiver. Follow the steps below to connect the UM425 to your GPS receiver: Accessory connector...
Installing the Hardware Table 8 - Common GPS receivers and connections GPS NMEA0183 OUTPUT Wire Color Ground Wire Color (Connect to GREEN WIRE (connect to BARE GPS Manufacturer Model Number(s) on UM425) WIRE on UM425) Furuno GP1650, GP1850 White Black Furuno GP30, GP36 White...
Installing the Hardware When the GPS receiver is correctly connected, the display shows GPS Data OK. If there is a problem with the GPS connection, the display shows Check GPS. When the display shows GPS Data OK, press the button to SELECT open the GPS status screen and see detailed GPS data: Time...
Installing the Hardware If Daylight Savings Time is currently in effect, select On. If Daylight Savings Time is not currently in effect, select Off. Press the button. The radio activates the new time setting and SELECT returns to the GPS Setup menu. Connecting to a charplotter The UM425 provides a standard NMEA0183 GPS output that you can connect to a chartplotter.
Installing the Hardware Disconnect the accessory cable from the accessory connection on the radio. Connect the BLACK wire of the accessory cable to the GROUND WIRE of your external speaker. Connect the RED wire of the accessory cable to the POSITIVE (+) WIRE of your external speaker.
Installing the Hardware Using the PA feature Press and hold the MENU- button for two seconds to activate the PA feature. The display shows PA in the upper right hand corner. Public Address Press and hold the microphone Mode Selected button.
If the antenna has been damaged, you should not transmit except in the case of an emergency. A defective antenna may cause damage to your radio. • You should arrange for periodic performance checks with your Uniden dealer. Common questions Problem Things to Try The radio won’t power on.
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Where can I find my radio’s Look on the bottom side of the radio serial number? The radio won’t let me enter Contact customer service by visiting the customer my User MMSI. What do I do? support page on www.uniden.com.au or www.uniden.co.nz.
Maintenance and Troubleshooting Engine Noise Suppression Interference from the noise generated by the electrical systems of engines is sometimes a problem with radios. The UM425 has been designed to be essentially impervious to ignition noise and alternator noise. However, in some installations it may be necessary to take measures to further reduce the effect of noise interference.
Specifications Specifications Table 9 - Radio specifications (All specifications are subject to change without notice.) General Controls , Squelch OLUME Status Indicators Transmit power, Scan mode, Triple Watch mode, Battery High, Battery low, USA, CAN, INT, Memory, GPS status and Channel Display Display LCD (Full Dot Matrix) Buttons...
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Specifications Transmitter Power Output 1 watt or 25 watt (user selectable) Power Requirement 25 watts output: 6A@13.8V DC Modulation ±5 kHz deviation Hum and Noise Signal-to-Noise 45 dB with 3 kHz deviation with 1000 Hz modulating frequency (nominal) Audio Distortion Less than 8% with 3 kHz deviation with 1000 Hz modulating frequency Spurious Suppression...
Specifications Channel and frequencies Table 10 - International Channel Frequencies and Channel Tag Ch No. RX Freq TX Freq Status Full Name 160.6500 156.0500 Duplex Marine operator 160.7000 156.1000 Duplex Marine operator 160.7500 156.1500 Duplex Marine operator 160.8000 156.2000 Duplex Marine operator 160.8500 156.2500...
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Specifications Table 10 - International Channel Frequencies and Channel Tag (cont'd) Ch No. RX Freq TX Freq Status Full Name 156.5750 156.5750 Simplex Non commercial 156.6250 156.6250 Simplex Non commercial 156.6750 156.6750 Simplex Port operation 156.7250 156.7250 Simplex Port operation 156.7750 156.7750 Simplex, 1W...
Specifications Table 12 - Canadian Channel Frequencies and Channel Tag Ch No. RX Freq TX Freq Status Full Name 160.6500 156.0500 Duplex Marine operator 160.7000 156.1000 Duplex Marine operator 160.7500 156.1500 Duplex Marine operator 4 “A” 156.2000 156.2000 Simplex Canadian coast guard 5 “A”...
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Specifications Table 12 - Canadian Channel Frequencies and Channel Tag (cont'd) Ch No. RX Freq TX Freq Status Full Name 156.5750 156.5750 Simplex Non commercial 156.6250 156.6250 Simplex Non commercial 156.6750 156.6750 Simplex Port operation 156.7250 156.7250 Simplex Port operation 156.7750 156.7750 Simplex, 1W...
Specifications NMEA Operation This radio supports NMEA0183 version 3.01. NMEA Input If you have difficulty getting the UM425 to receive data from your GPS receiver, check the device’s configuration. It should be set to the parameters shown in the table below. Table 13 - NMEA Input Parameters The radio supports RMC, GLL, GNS, Baud rate...
Regulations and Safety Warnings Regulations and Safety Warnings Basic radio guidelines You should familiarize yourself with the rules on marine radios and be aware of which rules apply to your boat. DSC: Frequently Asked Questions The following information is sourced from the Australian Maritime Safety Authority's DSC FAQ.
Regulations and Safety Warnings How can a MMSI be applied for? The Australian Maritime Safety Authority allocates MMSI. To apply for an MMSI complete the MMSI Application form available for download via www.amsa.gov.au/mmsi. This page has important information about MMSI and DSC radio.
Australia or New Zealand and will expire two (2) years from the date of the original retail sale. If a warranty claim is made, this warranty will not apply if the Product is found by Uniden to be: (A) Damaged or not maintained in a reasonable manner or as recommended in the relevant Uniden Owner’s Manual;...
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