Electronics: Garmin Signal VHF 400/220 - VHF radios with AIS that do not need a splitter

More than four years after the takeover of Vesper Marine, Garmin is launching its first self-developed VHF radio system on the market with the Signal VHF devices. Vesper was primarily known for its innovative Cortex system a VHF radio with an integrated AIS transponder, monitoring functions and a software-defined radio architecture. According to Garmin, the Signal series is based on the Vesper DNA. The most important difference between the two models lies in the AIS function: the VHF 400 can not only receive AIS targets from others via the integrated Class B transponder (SOTDMA), but can also transmit its own position, course and speed. The VHF 220, on the other hand, is limited to AIS reception.

• Vesper Marine Cortex V1 - VHF, AIS and monitoring system

No splitter necessary, everything via one antenna

A special technical feature of the Signal series is the installation with only a single VHF antenna for radio and AIS - an antenna splitter is not required. The fact that both radios handle VHF communication and AIS via one antenna suggests that Garmin has adopted the software-defined radio architecture (SDR) from Vesper.

Software Defined Radio: How it works

A software-defined radio differs fundamentally from conventional radio devices: instead of separate hardware receivers for VHF voice and AIS, an SDR digitises the entire received frequency spectrum and processes the signals using software. This makes it possible to monitor all VHF channels (channels 1 to 88) and the AIS range (channels 87 and 88) simultaneously with a single receiver. Conventional radios with a separate AIS receiver, on the other hand, require two receivers and an antenna splitter that splits the signal - with potential losses for both functions. The SDR architecture also allows functions such as the simultaneous recording of several channels or the continuous scanning of all frequencies without interrupting active radio traffic.

This architecture would also explain the extended monitoring functions: All VHF channels are continuously checked for activity in the background, and six channels can be listened to in parallel. A VHF playback function records audio transmissions on up to three channels simultaneously - missed radio messages can be listened to for up to three minutes afterwards. These functions were characteristic of the Vesper Cortex system and indicate a similar technical basis.

The adaptive noise cancellation works with automatic squelch and blocks out background noise such as wind, waves and engine noise. The DSC function (class D) allows distress signals to be sent to nearby vessels using the distress button. With the VHF 400, a DSC call to nearby boats can be started directly via the AIS screen.

• Also interesting: Em-Trak X100 - VHF radio with AIS and app control

Wireless microphone with cable

Another special feature of the Signal series is the supplied handheld microphone: it only requires a power supply and is wirelessly connected to the main unit. The microphone has an integrated five-watt loudspeaker, its own adaptive noise cancellation and can be mounted in any position. The head unit itself does not have its own loudspeaker, but can be connected to an external loudspeaker. An intercom function enables direct communication between several signalling devices and the optional slave stations.

Remote control and network integration

The optional Signal RM 100 remote control station (€599) enables full control of the VHF radio from a second helm station or flybridge. Each Signal VHF 220 or 400 supports up to five RM 100 remote stations. The slave station also has a 3.5-inch colour display and a wireless handheld microphone. The connection between the remote station and the main unit is made via Garmin's BlueNet network.

Integration into existing on-board systems takes place via NMEA 2000, Garmin Marine Network or Garmin BlueNet. AIS, DSC and navigation data are shared via NMEA 2000. Both devices contain a GPS receiver and support an external GPS antenna if the installation position impairs reception. The devices are compatible with 12 and 24 volt on-board networks.

An integrated WLAN enables software updates via the ActiveCaptain app and the wireless transfer of AIS, GPS and course data. According to Garmin, the signalling devices are compatible with the Navionics Boating App - a feature that Garmin has adopted from Vesper and which brings AIS data to mobile devices via WLAN. Further information: www.garmin.com

Technical data:

Garmin Signal VHF 400:

• Type: VHF radio with AIS transponder class B
• Display: 3.5 inch colour touch display
• AIS: Class B transponder (SOTDMA), transmit and receive function
• DSC: Class D
• Antenna: one VHF antenna for radio and AIS (no splitter required)
• VHF playback: up to 3 minutes on 3 channels simultaneously
• Channel monitoring: all VHF channels in the background, 6 can be monitored in parallel
• Hand-held microphone: wireless, 5 watt speaker, adaptive noise cancellation
• Loudspeaker in the main unit: none
• Remote stations: up to 5 RM 100 per radio
• Connectivity: NMEA 2000, Garmin Marine Network, Garmin BlueNet, WLAN
• GPS: integrated, external antenna supported
• On-board voltage: 12 V and 24 V
• Protection class: IPX7
• Price: €1,499.99 (RRP)

Garmin Signal VHF 220:

• Type: VHF radio with AIS receiver
• Display: 3.5 inch colour touch display
• AIS: receive function only (no transmitter)
• DSC: Class D
• Antenna: one VHF antenna for radio and AIS reception (no splitter required)
• VHF playback: up to 3 minutes on 3 channels simultaneously
• Channel monitoring: all VHF channels in the background, 6 can be monitored in parallel
• Handheld microphone: wireless, 5 watt loudspeaker, adaptive noise cancellation
• Loudspeaker in the main unit: none
• Remote stations: up to 5 RM 100 per radio
• Connectivity: NMEA 2000, Garmin Marine Network, Garmin BlueNet, WLAN
• GPS: integrated, external antenna supported
• On-board voltage: 12 V and 24 V
• Protection class: IPX7
• Price: 999.99 € (RRP)

Garmin Signal RM 100 (remote control):

• Display: 3.5 inch colour touch display
• Function: complete remote control for VHF 400/220
• Handheld microphone: wireless
• Intercom function: Communication between remote station and main unit
• Connection: Garmin BlueNet
• Number per radio: up to 5 units
• Price: €599.99 (RRP)

More articles on this topic:

• Market overview of AIS transponders: See and be seen
• Navigation with AIS: How to use the system correctly
• Using marine radio correctly: How to radio correctly