FAQ and troubleshooting

XLX159 is a multi-mode amateur radio reflector running the open-source XLX daemon. It bridges D-Star, DMR, YSF, P25, NXDN, and M17 in a single place, with cross-mode audio mixing so a QSO can span multiple protocols.

No. The reflector is open. Point your hotspot, repeater, or client at xlx159.duckdns.org using the port for your mode and you are on the air.

D-Star users may need to register their callsign on the gateway side if the host system requires it, but the reflector itself does not gate access by callsign.

Yes. XLX159 is run by volunteer operators as a public service to the amateur radio community. There is no fee, no tier, and no upsell. The reflector infrastructure is paid for out of pocket by the operators.

Use the contact form on the home page. Reports go to the operator team and are reviewed within 24 hours. For technical issues, also check the Rules page for the operator's preferred contact channels.

Three things to check, in order:

1. Port. Make sure the port matches your mode. D-Star is 30001, DMR is 62030, YSF is 42000, M17 is 17000. A common mistake is putting 30001 in the DMR field.
2. Firewall. Your hotspot or home network may be blocking outbound UDP on the mode port. Try a different network (mobile hotspot) to confirm.
3. Hostname typo. The exact hostname is xlx159.duckdns.org with no protocol prefix, no port suffix, no path. Copy it from the Connection page.

If all three check out and it still fails, the reflector may be temporarily down for maintenance. The status board on the home page shows the current state.

This is almost always a one-way path issue.

Can transmit, not receive: the reflector is sending audio back to you, but your hotspot's RX frequency is wrong, or the audio is being muted. Check the MMDVM log for "RX" entries.

Can receive, not transmit: the reflector is not hearing you. Check that your radio is on the right frequency and that the PTT line is making it to the MMDVM board.

For DMR specifically: this is usually a Time Slot mismatch. Try TS2 instead of TS1.

Most common cause: poor RF path between your radio and the hotspot, or poor network path between your hotspot and the reflector.

For RF issues, get the antenna closer or use a better one. Hotspots under 100 mW into a rubber duck have very short effective range.

For network issues, check your ping time to xlx159.duckdns.org from the Pi-Star admin page. Above 200 ms is suspect; above 500 ms will cause dropouts.

The D-Star registration is on the gateway (ircDDB or DCS), not the reflector. Register on whichever gateway you are using and wait 10-15 minutes for the change to propagate.

If you registered and still get the error, double-check the callsign spelling in your radio. A typo in the callsign field is the most common cause.

The XLX daemon runs a separate audio handler for each module. When audio arrives on module A (D-Star), it is decoded and re-encoded to the format of any other active module. The latency is typically 1-2 seconds for a round trip.

Bridging is enabled by default between modules A, B, C, and F. Modules D and E (P25 and NXDN) are bridged to DMR by default; cross-mode bridging to and from P25/NXDN can be turned on by the operator.

Yes. Module A is bridged to DCS by default, so any D-Star reflector reachable via DCS (REF, XRF, DCS) can be addressed through module A. Module B is bridged to Brandmeister, so any DMR talkgroup can be reached. Module C is bridged to FCS for YSF rooms.

Set the URCALL (D-Star) or talkgroup (DMR) on your radio to the target designator. Audio will route through XLX159 to the remote network.

No. The reflector is shared infrastructure. All audio is mixed to all connected stations. If you want a private QSO, use a different mode (DMR has talkgroup privacy through the BM self-service, D-Star has private reflectors via ircDDB).

Most modern dual-band mobile and handheld radios support at least one of DMR, D-Star, or YSF. Yaesu handhelds (FT-60, FT-70, FT-5D) support YSF natively. Icom handhelds (ID-51, ID-52) support D-Star natively. Any-Tone (TYT, Baofeng DM-1701, etc.) supports DMR.

P25 and NXDN are usually only on commercial-surplus radios (Motorola, Kenwood, Harris). M17 is on a small number of open-source firmware radios and on Pi-Star / WPSD hotspots.

For D-Star, DMR, and YSF: a Pi-Star or WPSD image on a Raspberry Pi Zero 2 W with a generic MMDVM board. Total cost around $60.

For P25 and NXDN: same hardware, but make sure the MMDVM firmware supports P25 and NXDN (most modern builds do). The ZUMSpot and OpenSpot families work well.

For M17: a Pi-Star 4.2+ or WPSD build, with an MMDVM board running the M17 firmware. The OpenMMDVM board is a good choice.

The M17 Project maintains a list of compatible hardware on their site.

For D-Star and YSF: yes, if you have a D-Star repeater in range that is itself linked to XLX159. The repeater does the protocol conversion.

For DMR, P25, NXDN, and M17: same answer. A linked repeater is the cleanest way to use a digital radio without your own hotspot.

For a mobile or portable setup with no repeater coverage, you need a hotspot or a personal repeater (cross-band or digital).