em-trak B921 Class B AIS Transceiver - 2W CSTDMA

The B921 Class B AIS Transceiver by em-trak is a cutting-edge 2W CSTDMA device designed for marine enthusiasts seeking reliable and advanced AIS communication. Compact and robust, the B921 ensures seamless real-time AIS transmissions, providing you with comprehensive situational awareness on the water.

As the FCC requires all units sold in the US to be programmed by a qualified technician, please submit the form below for programming at the time of purchase. A copy of the MMSI registration or FCC Ship Station License is required along with the vessel master or owner's signature on the completed programming form.

Download Programming Form

Advanced Performance and Reliability

The B921 leverages em-trak's SRT-AIS™ Transceiver Engine to deliver top-tier performance and reliability. Its intelligent connectivity allows seamless integration with any chart plotter, while the integrated GPS technology ensures precise positioning. Designed for ease of installation, the unique FLEXI-FIT® bracket system gets you operational quickly with minimal effort.

Key Features

• Certified AIS Class B – 2W CSTDMA
• Global certification: USCG, FCC, Canada, Europe
• SRT-AIS™ Transceiver Engine for exceptional performance
• FLEXI-FIT™ bracket system for easy and secure installation
• Integrated high-performance GPS receiver and antenna (external antenna optional)
• IPx6 and IPx7 certified for water, pressure spray, and damp proofing
• Durable against vibration, shock, and extreme temperatures
• Compact and lightweight design
• Ultra-low power consumption – best in class
• Supports NMEA 0183 & NMEA 2000 interfaces
• Automated health and performance monitoring
• Silent mode (transmit-off) function
• Enhanced RF screening to protect against electromagnetic interference
• Built-in power surge protection

Physical & Environmental Specifications

Dimension (H x W x D)	150 x 115 x 45 mm
Weight	375 kg
Operating Temperature	-25°C to +55°C
Storage Temperature	-25°C to +70°C
Ingress Protection	IPx6, IPx7

Electrical Specifications

Supply Voltage	12V or 24V DC
Supply Voltage Range	9.6V - 31.2V DC
Average Current (at 12V)	135 mA
Peak Current	2 A
Average Power Consumption (at 12V)	1.6 W
Galvanic Isolation	NMEA 0183, NMEA 2000, VHF antenna port

Connectors

• VHF Antenna: SO-239
• GNSS: TNC
• Power: 12-way circular multipole
• NMEA 2000: 5-way Micro-C connector
• USB: USB Micro-B

Data Interfaces

• NMEA 0183: 2 bi-directional ports
• NMEA 2000: NMEA 2000 Ed 3.101, LEN=1
• USB: PC virtual COM port for NMEA 0183 data

Standards Compliance

• AIS Standards: IEC 62287-1 Ed. 3, ITU-R M.1371.5
• Product Safety Standards: EN60950-1 2006 +A11:2009 +A1:2010 +A12:2011 +A2:2013 EN62311:2008
• Environmental Standards: IEC 60945 Ed. 4
• Serial Data Interface Standards: IEC 61162-1 Ed 5.0, IEC 61162-2 Ed 1.0
• NMEA 2000: NMEA 2000 Ed 3.101
• GNSS Performance Standards: IEC 61108-1 Ed 2.0, IEC 61108-02 Ed 1.0

GNSS Capabilities

• Supported Systems: GPS, GLONASS, BeiDou, Galileo (supports two of any combination, or three including GPS and Galileo)
• Channels: 72
• Antenna Options: Internal or optional external antenna
• Time to First Fix (Cold Start): 26 seconds

VHF Transceiver Specifications

• VDL Access Scheme: CSTDMA
• Operating Frequency: 156.025 MHz - 162.025 MHz
• Channel Bandwidth: 25 kHz
• Transmitters/Receivers: 2 receivers, 1 transmitter
• AIS Receiver Sensitivity (20% PER): -111 dBm
• AIS Transmitter Power: 2 W (+33 dBm)

User Interface

• Indicators: Power, transmit timeout, error, silent mode

What's Included

• 1 x AIS Transceiver
• 1 x Power and Data Cable (2M)
• 1 x FLEXI-FIT™ Mounting Bracket
• Complete with Screws & Optional Fixing Tape

Product Specifications

AIS Class	B
Antenna Included	Yes
Display Included	No
Function	Receive/Transmit
GPS Included	Yes
Box Dimensions	6" H x 7" W x 8" L
Weight	1.55 lbs
UPC	672975210502

Additional Resources

Quick Guide (PDF)

Brochure (PDF)