Get started with dalSDR
Open sdr.kf2em.com in current desktop Chrome or Edge. Safari and Firefox are not supported receiver browsers.
Choose one receiver path
Select Connect receiver, then choose the path that matches your hardware.
| Receiver | Choose | What works today |
|---|---|---|
| RTL-SDR with an R820T-compatible tuner | RTL-SDR with WebUSB | Experimental in current desktop Chrome and Edge: select the receiver, then choose Start local spectrum. It has mock-device coverage, but physical receiver validation is pending. |
| SDRplay RSP1A or RSP1B | Local SoapySDR bridge | In desktop Chrome or Edge, a local bridge can discover a ready receiver and, when you select Start local spectrum, provide local IQ frames for the spectrum and waterfall. You may then choose to enable local audio. |
SDRplay: start the local bridge
Follow the RSP1A/RSP1B bridge guide and run the one command for your operating system. Then discover the receiver in dalSDR. If the launcher says local requirements are not ready, or the browser cannot list the receiver, use that guide’s one-time setup for your operating system and run the same launcher again. The radio, SDRplay software, bridge, and browser all run on the same computer.
What to expect after you connect
The direct R820T workspace is experimental. Both a started R820T path and a configured SDRplay bridge provide a spectrum, waterfall, optional local 12 kHz audio path, and frequency retune. The Sample loss field reports bridge receiver-overflow events or direct-path app-frame drops; it cannot calculate an exact missed-sample count. Select APRS while the local spectrum runs to monitor AFSK1200. Only FCS-validated packets appear, only in the current tab; they clear when the spectrum stops and are not uploaded or saved. A Receiver gain control appears only when the receiver reports a usable range and current value. RTTY is an experimental fixed 2125/2295 Hz, 45.45 baud local text prototype: copy appears only after start/stop framing checks and should be confirmed independently. CW is an experimental fixed 700 Hz, 100 ms-dot local Morse prototype: copy appears only after timing checks and should be confirmed independently. PSK31 is an experimental fixed 1000 Hz, 31.25 baud BPSK/Varicode local text prototype: copy appears only after framing checks and should be confirmed independently. WSPR monitors local four-tone activity near 1500 Hz; it does not decode stations or messages, or report spots. Local audio demodulation changes browser-side audio only; receiver-side mode controls and other decoder families remain unavailable.
For the direct RTL-SDR path, set PPM correction before starting local spectrum. The selected value is applied when the receiver starts and remains visible in its startup status; dalSDR does not offer a simulated calibration button.
Privacy and local operation
dalSDR has no account, analytics, or telemetry path. The bridge accepts only loopback connections and requires a token, which remains only in the current browser tab. RF, IQ, audio, decoded content, and receiver details stay on your computer unless you choose a future sharing feature. Follow the radio rules that apply where you operate.
dalSDR is receive-only. It provides no transmit, PTT, transmit-audio, or transmitter-control feature.