SI-TEX MDA-5H Hi-Power 5W SOTDMA Class B AIS Transceiver w/Built-In Antenna Splitter (w/o Wi-Fi)

The SI-TEX MDA-5H Hi-Power 5W SOTDMA Class B AIS Transceiver with Built-In Antenna Splitter represents a critical piece of vessel safety infrastructure for commercial maritime operations, law enforcement marine units, and serious recreational boaters who demand reliable automatic identification system (AIS) coverage. Operating at 5 watts of transmit power, this Class B transceiver broadcasts vessel position, heading, speed, and static data to other AIS-equipped vessels and shore stations—enabling maritime domain awareness, collision avoidance, and emergency response coordination across open water and coastal regions. The built-in antenna splitter eliminates the need for external splitting hardware, streamlining installation on vessels with existing VHF antenna systems.

SOTDMA (Self-Organized Time Division Multiple Access) technology ensures efficient, collision-free transmission by allowing the transceiver to self-assign time slots in the AIS maritime VHF bands (161.975 MHz and 162.025 MHz), maximizing data throughput in congested shipping lanes and coastal waters. The 5-watt transmission power class provides robust signal propagation sufficient for vessels operating within 20–30 nautical miles of shore and other traffic participants, meeting international Maritime Safety Committee (MSC) Class B specifications without requiring the higher power consumption of Class A systems. The integrated antenna splitter permits simultaneous operation with existing VHF radios on a single antenna, preserving deck space and reducing installation complexity—a critical advantage on smaller vessels or those with limited antenna mounting options. Compact dimensions (9 x 5 x 14 inches) and 3.25-pound weight allow straightforward mounting in pilothouse or below-deck equipment lockers, with standard marine-grade connector compatibility.

Law enforcement marine patrol units, Coast Guard auxiliary vessels, commercial fishing operations, and charter boat fleets benefit most from Class B AIS transceivers when simultaneous VHF radio and AIS operation is required without antenna system duplication. This transceiver integrates seamlessly with existing marine electronics suites—NMEA 0183 output feeds GPS/chart plotter systems for real-time position tracking and collision avoidance functionality. Installation requires a clear antenna placement location, 12/24-volt DC power supply (typical marine systems provide this), and integration with vessel GPS for position and heading data; consult your marine installer or vessel documentation for specific electrical and RF integration requirements. The absence of integrated Wi-Fi in this model eliminates unnecessary wireless connectivity, reducing electromagnetic interference risk and supporting secure maritime operations.