Troubleshooting

The app says "Demo mode" but my device is plugged in

In order of likelihood:

1. You plugged it in after starting the app. Click Re-check device in the amber banner. No restart needed.
2. Another program has the device open — SDR#, GQRX, CubicSDR, SDR++, a Soapy tool. Quit it, unplug and replug, click Re-check device.
3. Windows: the driver step has not been done for this USB port. See Getting started. It is once per port, not once per machine.
4. It is an RTL-SDR Blog V4. V4 support is experimental and off by default; use a V3-class dongle.
5. A cable or hub problem. Some USB cables are charge-only. Try a direct port on the computer rather than a hub.
6. The dongle has died. Test it in another SDR program.

macOS says the app is damaged or from an unidentified developer

That is the one-time Gatekeeper block — Spektra RF does not carry an Apple Developer ID yet. Use System Settings → Privacy & Security → Open Anyway, or the xattr command in Getting started. You only do it once.

Windows SmartScreen blocks the installer

Click More info → Run anyway. You can verify the file against the published SHA-256 in SHA256SUMS.txt first.

The window stays blank or white after the splash

Give it a moment on a slow machine; the first launch on an old Intel Mac can take 30–40 seconds.

If it stays blank, another program on the computer may be using port 38080. Spektra RF walks to the next free port automatically, but if it cannot find one, quit whatever is holding it — a local web server, Jupyter, a second copy of Spektra RF — and relaunch. Switching to another app and back also redraws the window.

"Port in use", or the app hangs for a minute after I restart it

The system keeps the port reserved for about a minute after a clean quit. Wait and try again.

Everything reads as occupied, or everything as free

The noise threshold is set wrong for this room, not the room being unusual. Run a fresh sweep and click Suggest threshold (or press T), then drag the line to fine-tune. See Find a free frequency window.

I hear nothing when I press Listen

Listen only works with an RTL-SDR; on other devices the button is not available. Check the system's output device and the level meter next to the button, and lower the squelch if it is cutting the audio off.

If you hear noise rather than audio, the system is probably digital (ULX-D, QLX-D, Axient, EW-D, Digital 6000, Sony DWX). FM demodulation cannot decode those — the noise still confirms a carrier is there.

The tinySA Ultra shows nonsense above 800 MHz

Ultra mode has to be enabled on the device itself: CONFIG → MORE → ENABLE ULTRA, code 4321. The app cannot switch it on remotely.

The Advisor returns fewer channels than I asked for

There is not enough measured free spectrum for that count with the chosen profile and device families. Try the other profile, fewer channels, or a wider band. See Coordinate a show with the Frequency Advisor.

Nothing happens at all when I open the app

The scanner engine writes a log at start-up: on macOS in your temp folder as spektra-sidecar.log (open Terminal, type open $TMPDIR), on Windows in %TEMP%. Send it to support@squaresmile.de with a description of what you did.

Download and licence problems

These happen on the platform, before the app is involved.

Where to ask

support@squaresmile.de. For hardware problems, tell us which device and, on a Mac, paste the output of system_profiler SPUSBDataType | grep -i rtl so we can tell a V3 from a V4. For crashes, attach spektra-sidecar.log.