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.

Public release coming soon · Windows 10 and 11 Download status →

The idea behind JSQ One transport. Your choice of modem. One set of messaging services, independent of the supported waveform carrying them.
OPENJSQ / CHATSAPPLICATION VIEW
OpenJSQ Chats interface, showing example station conversations, incoming messages, and radio controls.
Real application interface with example station traffic. Explore the app →

The shift behind JSQ

One transport.
Your choice of 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 architecture
THE APPLICATION
Conversations File transfer Mail Network discovery
JSQ
COMMON TRANSPORTMessaging services built once
THE RADIO LINK
FSQ++HF & 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 participating stations for their heard lists to build a broader picture.

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 screen
OPENJSQ / NETWORKWHO HEARS WHOM
OpenJSQ network interface showing a graph of test stations and their radio connections alongside the heard-stations list.
Network Map · screenshot with example data. Link observations can be directional and age over time.

More than keyboard chat

The messages you need.
The tools to move them.

One familiar interface for conversations and information that needs to travel over amateur radio.

01 / CHAT

Keep the conversation moving.

Talk with individual callsigns or groups, and send via a relay station when that path is available.

Explore conversations →
02 / FILES

Send files, not crossed fingers.

Selective retransmission, integrity checks, and transfer resume make files practical over imperfect radio links.

Explore file transfer →
03 / MAIL

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
≈41 characters/sFSQ-42 · 205.1 bit/s raw
Simulated SNR
≈ −3 dB at FSQ-42For weaker signals: ≈ −16.5 dB at the slower FSQ-2.
Explore FSQ →

JG25 FM

Fast FM packets with selectable error protection. Experimental.

Maximum speed
2,400 bit/s rawJG2400/F0 · no payload error correction
Simulated SNR
+6.8 dB at 2400/F0For weaker signals: −1.3 dB at the slower 1200/F3.
Explore JG25 →

AX.25 FM

Standard packet compatibility, using radio audio or a KISS TNC.

Signaling speed
1,200 bit/s rawAX1200 · one fixed signaling rate
Simulated SNR
+7.6 dB at AX1200FM packet test: 9 in 10 intact 256-byte packets.
Explore AX.25 →

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 →

Compare speeds and simulated signal requirements →

One receiving station

Listen across modes.
Keep your conversation.

On an audio connection, enabled FSQ, AX1200, and JG25 receivers listen together. Eligible automatic replies use the caller’s mode, even when you select another for your own messages.

How multi-receive works →

At home. On a net. In the field.

Built for the way you operate.

Generated illustration of an operator using OpenJSQ on a rugged tablet beside a portable radio.

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 →

From the operator who built it

Why I built JSQ.

The story behind JSQ

I loved FSQ’s conversational simplicity and the ad hoc networks we could build with relay, heard lists, and station queries. I valued JS8’s weak-signal reception and AX.25 packet’s possibilities. But the capabilities lived inside different modem-centered systems. I wanted the conversation, the files, the mail, and the network to come first—with one transport that was independent of the modem.

Jerome Goddard II · W4IJG

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.