About

What is YSF?

YSF commonly refers to Yaesu System Fusion, Yaesu's C4FM digital voice system. In hotspot and gateway software, YSF also refers to reflector networks used to connect compatible radios, hotspots, repeaters, and gateways. YSF Live helps amateur radio operators find public YSF reflectors and check their availability.

How monitoring works

YSF Live runs lightweight protocol checks against listed public reflectors to see whether they respond. Callsign-level activity monitoring is separate and is limited to eligible U.S. reflectors. For those reflectors, YSF Live connects as a standard YSF client, sends the small keepalive needed to maintain the connection, and listens for signaling metadata. It never records voice audio.

Activity labels

Traffic now means qualifying traffic metadata was observed within roughly the last eight seconds. Active recently means it was observed within the last 15 minutes. Active in last 2 hours means the most recent qualifying activity was within the previous two hours. These are observations, not guarantees, and they can lag during network interruptions.

Search

Search is reflector-focused. It matches reflector names, YSF IDs, descriptions, countries, and regions. It does not search for operators by callsign.

YSF, System Fusion, WIRES-X, and FCS

Yaesu System Fusion is a digital-voice radio system that uses C4FM. WIRES-X is Yaesu's network for linking compatible nodes and rooms. YSF and FCS are separate reflector systems commonly reached through compatible hotspots and gateways. YSF Live lists public YSF reflectors; it is not a WIRES-X room directory and is not affiliated with Yaesu.

Availability checks

Availability checks are limited protocol-level probes run about twice per day. A successful check means the reflector returned a valid YSF response at that time. The 24-hour check-success rate is the share of YSF Live probes recorded during the preceding 24 hours that succeeded; with twice-daily checks, the sample size is intentionally small.

Community corrections

Reflector information may come from public host lists and automated classification, so mistakes are possible. Corrections and reflector-owner opt-out requests are welcome at [email protected].