System Fusion and Wires-X
System Fusion is Yaesu's digital voice and data protocol for amateur radio, using C4FM (Continuous 4-level FM) modulation to carry digital voice, images, GPS data, and text messages. One of Fusion's distinguishing features is its automatic mode detection — a Fusion repeater or radio can detect whether an incoming signal is analogue FM or C4FM digital and respond appropriately, making Fusion backwards-compatible with analogue FM radios in a way that DMR and D-STAR are not. Wires-X is Yaesu's internet linking system that connects Fusion (and analogue) nodes worldwide.
C4FM and Automatic Mode Select
System Fusion uses C4FM (Continuous 4-level FM) — a four-state frequency modulation scheme that encodes digital audio into an FM signal. The key advantage over DMR and D-STAR is Automatic Mode Select (AMS) — Fusion-capable repeaters and radios automatically detect whether an incoming signal is analogue FM or C4FM digital, and switch mode accordingly. This means an analogue FM radio can still access a Fusion repeater, while a Fusion radio on the same repeater enjoys the benefits of digital voice. No reconfiguration is needed.
Wires-X internet linking
Wires-X (Wide-Coverage Internet Repeater Enhancement System) is Yaesu's proprietary internet linking system. A Wires-X node consists of a Yaesu HRI-200 interface connected to a Yaesu transceiver and the internet. Nodes connect to Wires-X rooms — essentially conference bridges similar to D-STAR reflectors — allowing worldwide communication between linked nodes and repeaters. Users can connect to and disconnect from rooms using DTMF tones from a Fusion radio. The FT-991A, FT-3DR, FT-70DR, and most current Yaesu radios support Wires-X operation.
Get a Fusion-capable radio
Any current Yaesu dual-band or HF/VHF/UHF radio that supports C4FM will work. Popular options include the FT-70DR (affordable dual-band HT), FT-3DR (full-featured dual-band HT with touch display), FT-991A (HF/VHF/UHF all-in-one), and FT-DX10 for HF. Unlike D-STAR and DMR, no registration or ID number is required — programme your callsign into the radio and you are ready to go.
Find local Fusion repeaters
Use RepeaterBook.com filtered to System Fusion (YSF) mode to find local Fusion repeaters. Note that many Fusion repeaters also appear to support analogue FM via AMS. Look for repeaters connected to Wires-X if you want internet linking capability. The Wires-X website also has a node and room directory.
Connect to a Wires-X room
On a Wires-X-connected repeater, press and hold the DX button (or equivalent on your radio model) to enter Wires-X search mode. You can search for rooms by name or number and connect directly from your radio. Popular rooms include the America-Link (room 21080) and various regional rooms. Press the DX button briefly to disconnect from a room when done.
Use a Fusion hotspot
If there is no local Fusion repeater, a hotspot running Pi-Star configured for YSF (Yaesu System Fusion) mode connects your radio directly to Wires-X rooms or to the YSF network via your home internet connection. Pi-Star supports cross-mode bridging, so a YSF hotspot can also connect to DMR or D-STAR networks.
Can my analogue FM radio use a Fusion repeater?
Yes — this is one of Fusion's key advantages. When a Fusion repeater receives an analogue FM signal, AMS (Automatic Mode Select) detects it and retransmits it as analogue FM. Fusion radio users on the same repeater hear the analogue signal converted appropriately. The analogue FM user hears digital Fusion transmissions but does not get the digital benefits. Full digital mode requires both stations to use Fusion-capable radios.
What is the difference between Wires-X and IRLP/EchoLink?
Wires-X is Yaesu's proprietary internet linking system designed specifically for Fusion and analogue FM Yaesu nodes. IRLP (Internet Radio Linking Project) and EchoLink are open standards that work with any analogue FM repeater or node regardless of radio manufacturer. Wires-X provides tighter integration with Fusion radios — you can search and connect to rooms directly from the radio — but is limited to Yaesu nodes. IRLP and EchoLink have broader compatibility but less radio integration.
Is System Fusion only for Yaesu radios?
Officially yes — System Fusion and Wires-X are proprietary Yaesu protocols. However, open-source implementations like MMDVM and Pi-Star support C4FM/YSF mode, allowing non-Yaesu hotspots to connect to the YSF network. Fusion-to-DMR and Fusion-to-D-STAR bridges also exist through Pi-Star's cross-mode functionality. In practice, you need a Yaesu radio to access Wires-X rooms from a repeater, but can use YSF via hotspot with any compatible setup.
How does Fusion compare to DMR for a new digital voice user?
Both are solid choices. Fusion is simpler to get started — no registration, no codeplug, AMS backwards compatibility with analogue FM. DMR has significantly more repeaters and users worldwide and more affordable entry-level radios. If your area has good Fusion repeater coverage and you are already a Yaesu user, Fusion is the natural choice. If you want maximum network coverage and more radio choices at lower prices, DMR is the better option.