AS300 – Splitter

SKU: 001-1016


The AS300 Antenna Splitter is designed to allow an AIS Class B Transponder or an AIS Receiver to share the main VHF Antenna used by the VHF Radiotelephone, which removes the need and expense of installing an additional VHF antenna.

Comar Antenna Splitters are built to the highest standards to ensure that the performance of the connected AIS and VHF Radio equipment is not compromised.

Note: This product was previously known as the AST300


• Allows use of a single VHF Antenna installation shared between AIS and VHF Radiotelephone
• Automatic Routing of AIS or VHF Transmissions
• VHF transmissions have priority over AIS
• Works with an AIS Transponder (Class B) or AIS Receiver
• FM Antenna Connection for receiving Public Radio Broadcasts
• Rugged, Marinised Housing
• 12 V dc


• Enables AIS to be used with an existing installed antenna
• Removes the need and expense of installing a second antenna


• AV100 – Stainless Steel Whip Antenna
• AV400 – Heavy Duty Commercial GRP Antenna


• T200B – Class B AIS Transponder
• T200B-S – Class B AIS Transponder with internal antenna splitter



• Weight: 600g
• Dimensions: L 140 x W 120 x H 50 mm
• Mounting: To flat surface with case brackets
• Connections: Power: 1 m 2-core captive cable
• Antenna: SO239 UHF Connector
• VHF Radiotelephone: SO239 UHF Connector
• AIS Transponder / Receiver: BNC Connector
• FM Radio: RCA Phono Socket
• Construction: Grey aluminium housing; black end plates


• Power Supply: 12 / 24 V dc
• Operating Current: AIS / VHF Transmit: 135 mA (typical)
• AIS / VHF Receive: 65 mA (typical)
• Antenna
• Impedance: AIS / VHF / Antenna: 50 Ω; FM Radio: 75 Ω


• Frequency Range: 156.025 MHz to 162.025 MHz
• Sensitivity: < -112 dBm
• Display: 3 Indicator LEDs (ON; AIS TX; VHF TX)
• Switching Time: From Receive to AIS TX or VHF TX: 20 microseconds


• IP rating: IP40
• Operating temp: -15°C to +55°C
• Storage temp: -20°C to +70°C
• Operating Humidity: Up to 93%
• Compass: Safe Distance 50 cm


• Conforms with: IEC 60945


• Supplied: AS300 Splitter with Bracket Mount
• Supplied: VHF Patch lead; 1 m; with 2x PL259 male connectors
• AIS Patch lead; 1 m; with 2x BNC male connectors
• FM Radio: RCA Phono Plug (no cable)
• Required: 4x M4 mounting screws