Keep the conversation moving.
Talk with individual callsigns or groups, and send via a relay station when that path is available.
Explore conversations →Digital messaging for amateur radio
Your radio.
A complete messaging station.
Chat, exchange files, leave messages, and see who hears whom. Use HF or FM radio with one application.
Free · Windows 10 and 11, Linux and Raspberry Pi Download →
OPENJSQ / CHATSAPPLICATION VIEW
The shift behind JSQ
Chat, mail, and files.
Independent of the modem.
Conventional digital-mode software often ties its services to one waveform. JSQ separates the messaging system from the modem, so the same transport services work over different supported radio links.
Explore the JSQ architectureTHE APPLICATION
Conversations
File transfer
Mail
Network discovery
JSQ
COMMON TRANSPORTMessaging services built once
THE RADIO LINK
FSQHF & FM
AX1200FM packet
JG25Experimental FM
Compatible peers are required; using different modems does not automatically bridge distinct radio paths. Compatibility details →
A picture of your radio network
See who hears whom.
Your radio network is more than a list of callsigns. OpenJSQ turns received traffic and station reports into a visual map of the links between stations.
- See connections. Find out which stations have heard one another.
- See signal quality. Directional observations show that a path can be stronger one way than the other.
- Discover beyond your receiver. Ask stations for heard lists to see possible relay paths. You choose the route.
This maps radio connectivity, not geographic positions. The picture reflects available observations, not a guarantee that every displayed path is currently usable.
Tour the Network screenOPENJSQ / NETWORKWHO HEARS WHOM
More than keyboard chat
The messages you need.
The tools to move them.
Chat, send files, or leave mail without switching applications.
Recover missing blocks.
Verify the file.
Selective retransmission, integrity checks, and transfer resume make files practical over imperfect radio links.
Explore file transfer →Leave a message for later.
Hold mail for a station that is off air, or use a willing third-party mailbox station to keep it until the recipient returns.
Explore store-and-forward mail →The radio link
Different radio paths.
The same messaging services.
Choose a supported waveform for the link and the station you want to reach. FSQ serves HF and FM keyboard work; AX1200 and experimental JG25 serve FM packet links. The JSQ services above them remain consistent.
FSQ / FSQ Fast FM / HF
HF & FM keyboard chat, with classic FSQ compatibility.
- Maximum speed
- 205.1 bit/s rawFSQ-42 · ≈41 characters/s
- Estimated Minimum SNR
- ≈ −3 dB at FSQ-42For weaker signals: ≈ −16.5 dB at the slower FSQ-2.
JG25 FM
Fast FM packets with selectable error protection. Experimental.
- Maximum speed
- 2,400 bit/s rawJG2400/F0 · no payload error correction
- Estimated Minimum SNR
- +6.8 dB at 2400/F0For weaker signals: −1.3 dB at the slower 1200/F3.
AX.25 FM
AX.25 packets through existing digipeaters, using radio audio or a KISS TNC.
- Signaling speed
- 1,200 bit/s rawAX1200 · one fixed signaling rate
- Estimated Minimum SNR
- +7.6 dB at AX1200FM packet test: 9 in 10 intact 256-byte packets.
Illustrative waveforms. Speeds are signaling or continuous-text rates, not delivered file throughput. SNR figures are simulated estimates, not guaranteed operating minimums: FSQ uses an HF text-copy test; JG25 and AX1200 use an FM packet-delivery test. Compare SNR only within the same test; real radio paths need margin. Test conditions →
One receiving station
Listen across modes.
Keep your conversation.
On an audio connection, enabled FSQ, AX1200, and JG25 receivers listen together. Select AX1200 for your messages and still answer a permitted FSQ station query in FSQ. One transmitter sends one signal at a time.
See multi-receive in use →At home. On a net. In the field.
Built for the way you operate.
Bring the net together.
Share an @CLUB conversation. Use Net mode to pause automatic traffic during a directed net.
Groups & net controls →Keep information available.
Offer a shared file library. Exchange ICS-213 forms, then print or save them.
Sharing & forms →Keep more in view.
Pop out Chats, Inbox, Files, Network, and Channel to monitor several views on one screen or across monitors.
Separate windows →Take your setup along.
Keep separate shack and field profiles, with portable configuration and a guide that works offline.
Field operation →Connect with other operators
Bring your questions.
Share your experience.
Get setup help, report bugs, and discuss feature ideas in the OpenJSQ community.
Explore the community →Ready to explore?
Start with the radio you have.
Find the right starting mode, see the equipment setup, and learn what works with existing digital-mode stations.