West Marine, Uniden VHF Marine Band Radios

VHF Marine Band radios, protocol, radio communication theory, practical advice; AIS; DSC; MMSI; EPIRB.
jimh
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West Marine, Uniden VHF Marine Band Radios

Postby jimh » Mon Apr 02, 2018 9:22 am

West Marine announced two new VHF Marine Band CLASS-D digital selective calling (DSC) radios designated models VHF490 ($140) and VHF595 ($160). These radios are identical in their internal electronic components and differ only in the arrangement of the front panel keys, overall size, and the color (and perhaps size) of the LCD display. The same radios are also available as the UNIDEN models UM385 ($144) and UM435 ($168), where the microphone does not have as many buttons or the buttons are in different locations on the microphone and the LCD display color is amber rather than green; UNIDEN is the actual manufacturer of these radios. All are available in either white or near-black cases, except the VHF490 which is available only in a white-gray case. The FCCID AMWUT655 appears to cover all these models.

Three models are pictured below. The photographs are not precisely to scale so size comparison is not particularly possible with accuracy.

WM595.png
The West Marine VHF595 radio with black case.
WM595.png (112.09 KiB) Viewed 11976 times


WM490.png
The West Marine VHF490 radio, available only in two-tone gray-white case as shown.
WM490.png (102.21 KiB) Viewed 11976 times


UNIDEN385.png
The Uniden UM385 radio in black. Note the difference in the LCD display color and lack of channel changing buttons on the microphone.
UNIDEN385.png (121.16 KiB) Viewed 11969 times


UM435.png
The Uniden UM435 radio in white-gray. Note position of buttons on the microphone.
UM435.png (124.79 KiB) Viewed 11923 times


These many models all have an NMEA-0183 interface provided on the rear panel by an "accessory cable" that terminates in loose individual wires for connection to other devices. The owner's manual uses incorrect designators to refer to the signal names, but the wire insulation colors are in conformance with NMEA recommendations. The actual wire colors with the corrected signal names are shown below:

TALKER A    = White
TALKER B = Brown
LISTENER B = Green
LISTENER A = Yellow


The user manual provides instructions for interconnecting the radio to a GNSS receiver or chart plotter, but does not use the proper nomenclature (TALKER or LISTENER, A or B) when describing the signals from the other devices or signals from the radio; the descriptions also use misleading polarity markings such as the plus-sign or minus-sign. Signal names are described as "NMEA_IN" or "NMEA_OUT" with polarity designators.

The instructions do properly warn the user to not connect the TALKER B output to ground. The instructions under the heading "Connecting to a Chartplotter" are confusing, as the term "chartplotter" is used for describing the connection for the WHITE (TALKER A) wire, but the term "GPS receiver" is used for the connection of the BROWN (TALKER B) wire. A "GPS receiver" would not normally have a NMEA-0183 input to interconnect with a radio, nor would the TALKER A/B pair be split and connected to different devices. This error in the installation instructions could confuse owners of the radios attempting to interface them to other devices.

The USCG has asked NMEA to help implement more consistency in NMEA-0183 interfaces and more clarity in their interconnection. These radios have progressed to using proper wire color, but still employ non-conforming signal names and confusing narratives of interconnections.

In parts of the owner's manual the accessory cable is shown as being integral to the radio, and in other parts of the owner's manual the accessory cable is shown as being provided on a cable with a connector on one end that apparently mates with a connector on the rear panel of the radio. In photographs of the rear panel of the radio in some test results, the actual arrangement appears to provide a connectorized cable that mates with a cable-end connector coming from the radio on a short extension cable.

The owner's manual comments on interfacing and NMEA sentences as follows:

    The radio supports RMC, GLL, GNS, GGA and ZDA sentences. When these sentences are received, the radio displays latitude/longitude, date, time, course, and speed. If any sentence except an RMC or GLL sentence is received, the radio uses the information based on the following priority order.

    • Status: RMC > GLL > GNS > GGA
    • Latitude/Longitude: RMC > GLL > GNS > GGA
    • UTC Time: RMC > GLL > GNS > GGA > ZDA
    • Date: RMC > ZDA
    • Speed/Course: RMC

As can be inferred from the above, sending RMC to the radio should be all it needs.

As required by the FCC to be sold in the USA, the radios have been thoroughly tested by FCC-approved testing laboratories and found to be in compliance with the applicable standards for radio emissions and DSC operation according to FCC Part 80 regulations, IEC 60945, and ITU-R M.493-13.

The West Marine-labeled radios are sold only through West Marine. The Uniden radios are sold by several distributors and may be available at further discounts from the prices mentioned above.