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em-trak S100 AIS Antenna Splitter wiring diagram
Powered splitter for one VHF antenna shared by a VHF radio and Class B AIS. Accepts 9.6–31.2 V, consumes less than 0.15 A at 12 V and uses a 1 A protected supply. VHF transmission takes priority; antenna ports are RF signals, not DC outputs.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V / 24 V
- Continuous draw
- 0.2 A
Wiring diagram
How the S100 is wired.
Open this example in Crimp to use your own parts and cable lengths. Review the assumptions and installation notes as you adapt the circuit.
This supply example retains the manufacturer's 1 A fuse. Follow the complete installation notes for connector polarity, mounting, controls and commissioning; verify the actual cable route and equipment revision. Manufacturer installation manual
Edit this wiring exampleCable sizing for this example
Use the diagram as a starting point for your installation. Replace the example equipment and cable lengths with your own, and check the connections against your exact model's instructions.
10 ft one way
12 V system
- Wire
- 16 AWG · 1.5 mm²
- Example fuse
- 1 A
- Design current
- 0.1 A
- Voltage drop
- 0.1%
Sized against ABYC E-11. The design current is the part's continuous draw. The length is one way; voltage drop includes an equal-length return.
Run-length and manufacturer assumptions
The editable example uses 3.048 m (10 ft) runs unless a shorter run is stated. Metric overviews round these to 3 m. Adapt the parts and lengths to your installation before choosing cable and protection.
This supply example retains the manufacturer's 1 A fuse. Follow the complete installation notes for connector polarity, mounting, controls and commissioning; verify the actual cable route and equipment revision. Manufacturer installation manual
Supporting parts
- 20 ft total of 16 AWG (1.5 mm²) marine cable
- Terminations for 16 AWG cable, matched to the equipment's screw terminals, leads or studs
- 1 A fuse and holder on the positive run
- Heat-shrink, strain relief and terminal boots sized to the cable
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Installation notes
Before you install.
Open a question for model-specific guidance and sources.
Verified against the manufacturer's documentation (rev. 201-0206:3), checked 2026-10-01. Manufacturer documentation →
Sharing an antenna has a transmit priority
The S100 connects one marine VHF antenna to a VHF voice radio and a Class B AIS transceiver or receiver. It also offers an optional FM broadcast receiver output. The voice radio takes priority if both transmit together: AIS reports cannot be transmitted during that voice transmission. Confirm the AIS class and connector compatibility before fitting it; the published limits are 25 W at the VHF port and 12.5 W at the AIS port, not DC load figures.
Wire the independent supply
Connect red to positive through the recommended 1 A fuse or suitable protected circuit and black to the DC negative return. The permitted input is 9.6–31.2 V for nominal 12/24 V systems. The catalog uses 0.15 A as the upper bound of the stated less-than-150 mA draw at 12 V. It does not treat radio transmit watts as battery consumption; the radio and AIS require their own protected supplies.
Keep RF and power connections distinct
Use the labeled ANTENNA, VHF and AIS sockets and the supplied coaxial interconnects. Do not swap the radio and AIS ports. On the auxiliary cable, white is the FM antenna output; blue and green join to the FM antenna ground. Insulate unused FM leads individually. These are RF connections, even though the wire colors can resemble supply wires. The three RF markers on the symbol carry no modeled DC current.
Mount and commission the complete radio path
Choose a protected accessible position and route coax without sharp bends or connector strain. Connect the antenna and radios before testing transmission. With power applied, confirm the power indicator, then check the VHF transmit indicator during an appropriate radio check and the AIS indicator when the transceiver sends. A lit power lamp alone does not prove correct antenna routing. Inspect coax and connector assignment if transmit indicators or range are wrong; verify supply polarity, fuse and voltage if the power indicator is dark.
Manual and scope
em-trak installation manual, 201-0206:3; printed pp. 11–19, especially supply p. 15 and RF limits p. 19. The original PDF is retained in the marine source ledger. The drawing represents the identified electrical interfaces; it does not simulate the equipment’s mechanical performance, radio signals or fluid system. Unpublished connector ampacity and startup current remain unspecified.
Technical reference
Specifications and terminal map.
Check the model, ratings and connection points against your own unit before choosing installation hardware.
Catalog specification
Powered splitter for one VHF antenna shared by a VHF radio and Class B AIS. Accepts 9.6–31.2 V, consumes less than 0.15 A at 12 V and uses a 1 A protected supply. VHF transmission takes priority; antenna ports are RF signals, not DC outputs.
- Nominal voltage
- 12 V
- Compatible systems
- 12 V / 24 V
- Continuous draw
- 0.2 A
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
Red +
positive · input
Black −
negative · input
Antenna RF
signal · bidi
VHF RF
signal · bidi
AIS RF
signal · bidi
A dash means a current rating is not specified here.
Sources and sizing method
Equipment specifications. Model details, ratings and terminal roles come from the catalog. Check your unit’s label and current manufacturer documentation for its exact revision.
Example sizing. Sized against ABYC E-11 — the US reference, and what Transport Canada accepts as an alternative to TP 1332 for pleasure craft under 24 m. Results use the example current and run length shown above. Set your actual equipment, lengths and installation conditions in Crimp before choosing hardware.
Read how the sizing worksNext step
Plan your installation with S100.
Open this example as a new project, or add this component to your existing diagram. Use your equipment and cable lengths to review the sizing.
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