When I was a kid, my father’s fixed-mount VHF radio intimidated me. Perhaps this had something to do with getting scolded for playing with a live mic one day, but there was no escaping the radio’s clunky, analog design. Other contemporary marine instruments, including radar, were also knob-intensive, but at least there was bloblike imagery to distract from the less-than-intuitive user interface. Not so with VHF radio. Worse, there was the radio’s squelch knob: Get its level right, and conversation flowed; bungle it, as I often did, and static hiss became the soundtrack.
Even back then, I knew that evolution was gunning for that radio.
VHF radios revolutionized on-water communications when they came aboard in the early 1960s, but many contemporary radios still use the same undergirding technologies and similar user interfaces as their forebears. While Garmin’s Signal VHF 400 and 220 radios, and the companion Signal RM 100 remote station, aren’t the first marinized computers to function like fixed-mount VHF radios, they draw upon their predecessors’ DNA while packing fresh thinking into a more traditional-looking form.
The seeds for Garmin’s radios were planted in 2019, when Vesper Marine of New Zealand introduced Cortex. It was the first recreational-marine VHF radio to use software-defined radio architecture and a smartphone-like touchscreen handset that was hardwired to a head unit. Cortex also had a built-in Class B-SO Automatic Identification System transceiver, which allowed it to send and receive collision-avoidance data.
In January 2022, Garmin acquired Vesper. This, says Dave Dunn, Garmin’s senior director of marine and RV sales, helped the technology giant solve a long-vexing situation. “A lot of the VHFs that we’ve had in the past were Garmin-designed, but they weren’t Garmin-built,” he says.
But instead of taking a knob-intensive approach, Garmin kept innovating. “It was a ground-up effort,” says Carl Omundsen, Garmin’s engineering manager of marine communications (and a Vesper co-founder), about creating the Signal family. “We took the good from Cortex, and we wrapped it in a high-performance solution.”
Unlike Cortex’s smartphone-like handset, Signals use a traditional-style hand mic that’s hardwired to power and that wirelessly communicates with its head unit, which features edge-to-edge glass and a sunlight-readable 3.5-inch touchscreen color display. “There are some ergonomic advantages to having a smaller fist mic designed to be used [one-handed],” Omundsen says.
“The core focus for us was to make it as easy as possible for people to use and interact with their VHFs,” Omundsen says. For example, Signals offer smartphone-style Digital Selective Calling interfaces. “We wanted to make that as familiar as possible,” he says.
While the Signal VHF 400 (1,500),VHF220(1,000) and RM 100 ($700) look identical, differences abound. The 400 and 220 are full-featured VHF radios with integrated global navigation satellite system antennas and receivers, built-in Class D DSC, and the ability to display AIS data onscreen and share it across the vessel’s Garmin Marine Network. (Users can stream this data to their phones’ Garmin Boating app.)
That said, the 400 sports an AIS Class B-SO transceiver, while the 220 is a listen-only system.
The RM 100 is an optional remote station that connects to a 400 or 220 via a Garmin BlueNet cable.
All three Signals have SDR architecture, which allows Garmin to push out software-based updates. “It makes it easier for us to add features,” Dunn says.
SDR architecture also facilitates Signal’s advanced watch mode, which constantly scans all VHF radio channels for transmissions, and notifies users of activity. All three Signals have internal flash storage, and their playback feature records three minutes of activity on any three active channels.
Conveniently, all three Signals have automated squelch controls. This acts like an audio gatekeeper and mutes the speaker when there’s no activity, but unmutes it when a human voice breaks the noise. Users can still manually control their squelch.
To further ensure that transmitted and received communications are heard, the Signal family uses an adaptive noise cancellation feature, which leverages a kind of AI machine learning to improve audio quality.
“We trained it on actual data, going out on the boat and using it in windy conditions, when engine noise is on and when waves are lapping,” Omundsen says. “If you’re receiving a really weak, scratchy signal, the VHF receiver will run it through that machine learning model and remove a lot of that noise.”
Additionally, each fist mic has two microphones: one in front and one around back. “That’s so the algorithm can figure out where the wind’s coming from [and] what’s the best mic to use,” Omundsen says,
Other features include night mode, which shifts the displays’ color palettes to red. Stealth mode preserves the big-ocean theory; while over-the-air software updates deliver the latest features. Finally, all three Signals are small for installation options, and can be networked with external speakers or loudhailers.
Signal’s SDR architecture allows Garmin engineers to add features and refinements; its machine-learning algorithms help ensure clear communications and its automated squelch alleviates static-hiss. However, while Signals share AIS and GNSS data with any N2K-compatible MFD, users need a Garmin-built display to enjoy over-the-air software updates and MFD-based DSC calling.
So, if you are interested in upgrading your yacht’s vessel-to-vessel communications, check out the Signal family. There’s always the chance that you’ll miss old-school squelch knobs, but this concern is likely analogous to smartphone users pining for rotary telephones.
