SDRCat links your transceiver to a WebSDR, OpenWebRX+ or KiwiSDR receiver via CAT control. Change frequency on the radio — the SDR follows. Click a signal in the waterfall — the frequency and mode go to the radio. A live band scope while you operate on your own antenna.
SDRCat turns any WebSDR, OpenWebRX+ or KiwiSDR into a live band scope for your station.
Turn the VFO dial and the waterfall moves with it. Change band, change mode — everything updates automatically. Works with WebSDR, OpenWebRX+ and KiwiSDR. The SDR always shows exactly what your antenna hears, right now.
automatic real-time WebSDR · OpenWebRX+ · KiwiSDRSpot an interesting signal in the waterfall? Click it and your transceiver jumps straight to that frequency. With OpenWebRX+ and KiwiSDR, the mode (USB, LSB, AM, FM, CW…) is also sent to the radio automatically. Two-way sync, whichever side you tune from.
two-way sync freq + mode OpenWebRX+ · KiwiSDRThe Stations ▼ menu gives you four ways to find a receiver:
Click any station to open a detail panel with name, URL, version, tags and full frequency coverage by band. Open any station in SDRCat with a single click. Your recently visited URLs and saved favourites are always one click away at the top of the menu.
500+ stations searchable band detail panel favourites
Choose where the SDR audio comes out — your speakers, headphones, or a virtual audio cable such as VB-Audio or VAC. This lets you pipe the SDR signal directly into a decoder like WSJT-X, fldigi, or JS8Call without any physical loopback cable.
Decoding FT8, FT4, or WSPR from a WebSDR, OpenWebRX+ or KiwiSDR receiver has never been easier. When you stop SDRCat, your original audio output is automatically restored.
speakers / headphones VB-Audio / VAC WSJT-X / fldigi
Use the SDR as your receiver and your own radio as the transmitter — just like a real transceiver. Enable Mute on TX and the SDR audio silences itself the moment you key up, exactly the way a radio mutes its own RX during transmission. Release PTT and you're back instantly. No feedback, no echo, no manual switching.
RX via SDR TX via your radio automaticIn CW mode a slider shifts the SDR a few hundred Hz so the waterfall cursor lands on the exact audio tone you're using. Adjust it while operating and the display updates live. The offset is automatically reversed when you click a signal, so the radio always lands on the right frequency.
CW / CWR 400–1000 HzIcom, Yaesu, Kenwood, Elecraft — if it has a CAT port, SDRCat can control it. Connect directly via serial/USB or through HamlibServer over the network. You can run WSJT-X and SDRCat on the same radio at the same time, no conflicts.
Hamlib serial / network multi-app
Save your complete configuration — radio connection, poll speed, and audio device — as a named preset. Switch between setups in a single click. Everything is remembered automatically between sessions, so SDRCat is ready to go the moment you open it.
named presets auto-saveA quick tour through every panel — from first setup to operating.
A closer look at SDRCat in action.
A dedicated GUI tool by PA5DJ that manages rigctld and exposes your transceiver over TCP — so SDRCat, WSJT-X, and any other Hamlib-compatible program can connect simultaneously.
localhost and port as 4532.
Free — no registration required.
Built by a ham, for hams.
SDRCat started as a weekend project to scratch a specific itch: using a real SDR receiver as a live band scope while operating a transceiver. It links Hamlib CAT control to WebSDR, OpenWebRX+ and KiwiSDR — with full two-way frequency and mode sync — without requiring any changes to the SDR server. Built on .NET 10 Windows Forms with Microsoft WebView2 for the embedded browser.