RFChat Support

Everything here describes the app as it ships today — no roadmap, no promises.

About RFChat

RFChat is an offline group-chat client for amateur packet radio. It speaks the standard AX.25 protocol (UI frames) through any KISS-compatible TNC and adds a small open payload format, RFCHAT, for chat features such as rooms, directed messages, fragmentation, and position reports.

RFChat never uses the internet. There are no servers and no accounts: the radio channel itself is the chat room, and everything you see in the app is stored only on your device.

Getting Started

Set your callsign. Settings → My Callsign, e.g. YD0ABC-7.
Connect a TNC. Settings → Connection: enter a KISS-TCP host and port, or pick a Bluetooth KISS TNC from the scanner.
Say hello. You start in the CHAT-0 room on your working channel; anyone on the same frequency and room address will hear you.

No radio yet? Choose Explore Offline on the welcome screen to look around the app without any hardware.

Supported Platforms

iOS 16.2 or later (iPhone-focused; runs scaled on iPad)
macOS 14.0 (Sonoma) or later — the base-station app

Supported Connections

KISS over TCP — connects to a software modem or hardware TNC on your local network, for example Dire Wolf (default port 8001).
KISS over Bluetooth LE — battery-powered BLE TNCs such as the Mobilinkd TNC series.

If the link drops, RFChat reconnects automatically and shows the attempt count. After 100 attempts it pauses and asks whether to keep trying; you can also stop and reconnect manually at any time from the status indicator.

Set Your Callsign

Use a valid amateur radio callsign, optionally with an SSID: CALLSIGN-0 … CALLSIGN-15.
Tip: give each device its own SSID — for example -0 for a base station and -7 for a handheld.
Transmitting requires a valid amateur radio license in your jurisdiction. Receiving and Explore Offline do not transmit.

Chats and Shared Rooms

A room is a short group address shared over the air (1–6 letters or digits, like OPS-1). Everyone on the same frequency who joins the same address is in the same room.
Display names and member limits are local to your device — radio is broadcast, so any licensed station can always transmit.
Rooms can be muted per-room; a status dot on each room shows unread (green) or muted (yellow).
Room invites received over the air pop up an alert; joining is one tap.

Directed Messages

Start a message with @CALLSIGN to direct it to one station. Directed messages are addressed and can be signed (Ed25519) so the recipient can verify the sender — but they are not private. Amateur radio regulations prohibit encrypting message content, so anyone listening on the frequency can read every message, directed or not.

Radar and Location

The Radar shows stations that have chosen to broadcast a position report, plotted around your own anchor position.
Position sharing is off by default. Your position is only ever transmitted while “Share my position” is turned on in Settings.
Each blip shows distance, bearing, reported accuracy, and how fresh the report is. Only a station’s most recent position is kept.
The Mac base station can use fixed, manually entered coordinates instead of Location Services.

Explore Offline

The welcome screen’s Explore Offline button opens the full interface with no callsign and no connection — useful for a first look, App Store review, or planning a setup before hardware arrives. Nothing is transmitted in this mode.

Channels and CHIRP CSV

RFChat ships with regional seed channel lists and flags out-of-band frequencies for your selected region.
Channel lists can be imported from and exported to CHIRP-compatible CSV files (AirDrop or the share sheet on iOS; the File menu on macOS). CHIRP .img radio images are not supported.

Troubleshooting

Bluetooth TNC not found

Make sure the TNC is powered on and not already connected to another app or device — BLE TNCs accept one connection at a time. Check that Bluetooth permission is granted: iOS Settings → RFChat → Bluetooth (macOS: System Settings → Privacy & Security → Bluetooth). Then reopen the scanner.

Bluetooth permission was denied

RFChat needs Bluetooth only to talk to your KISS TNC. Re-enable it in iOS Settings → RFChat → Bluetooth, or macOS System Settings → Privacy & Security → Bluetooth, then reconnect.

Location permission and the Radar

On iPhone, the Radar anchors to your position, which needs Location permission (While Using). Your position is never transmitted unless “Share my position” is on. On the Mac base station you can instead set fixed coordinates in Settings — no Location permission needed.

KISS-TCP will not connect

Verify the modem is running and reachable: correct IP address and port (Dire Wolf defaults to 8001), same local network, and no firewall blocking the port. On first use iOS asks for Local Network permission — if you declined it, enable it in Settings → RFChat → Local Network.

“Disconnected” — what does Reconnect do?

RFChat retries dropped connections automatically and counts the attempts. After 100 attempts it pauses and asks whether to continue. If you stop, the status area becomes a Reconnect button — click or tap it to resume at any time. A successful connection resets the counter.

No stations on the Radar

The Radar only shows stations that actually broadcast a position report — many stations never do. Check that your own anchor is set (Location permission on iPhone, or base coordinates on Mac), that you are connected to your TNC, and that other stations on the frequency are sharing positions.

No messages received

Confirm the TNC link is Connected (not Reconnecting), the radio is on the same frequency as the other stations, the volume/audio path into the modem is correct, and you are in the same room address. The Monitor pane at the bottom shows every raw frame heard — if frames appear there but no messages, the room address probably differs.

Callsign rejected

Callsigns follow the AX.25 rules: up to 6 letters/digits plus an optional SSID of 0–15, e.g. YD0ABC-7. Punctuation and spaces are not accepted.

Contact Support

Email us at raguchiindo@gmail.com and include your app version, device model, TNC type (TCP or BLE), and what you expected to happen. We read everything.

System Requirements

iPhone running iOS 16.2 or later, or a Mac running macOS 14.0 or later.
A KISS-compatible TNC: software (e.g. Dire Wolf over TCP) or hardware (e.g. a BLE TNC), plus a transceiver for on-air use.
A valid amateur radio license to transmit.
No internet connection is required — or used.