Reviewed September 24, 2026 against source v1.7.41. Features and fixes are labeled by version. Check release availability.
Fewer receivers than expected
- Confirm every RTL-SDR Interface 0 appears in Receiver Setup with WinUSB marked ready.
- Connect the missing receiver by itself. If it works alone but not with the array, duplicate USB serials are likely.
- On v1.7.39+, use IDENTITY > GIVE UNIQUE SERIAL for supported factory-serial RTL dongles. Identify the intended unit and replug only after verification.
- Use a powered hub and split larger arrays across USB controllers when practical.
A receiver is listed but shows no signal
Confirm an antenna is connected and appropriate for the band, gain is not pinned too low, and the receiver is not temporarily controlled by periodic ADS-B or Search Director.
The waterfall is blank in Full Sweep
This is expected until the first pass completes. A full 24-1766 MHz sweep takes roughly 25 seconds on one receiver. The aggregate panel shortens the effective full-range pass by splitting it across the array.
Rendering feels slow
Check the aggregate status for WEBGL2 GPU or CANVAS FALLBACK. On fallback, reduce FFT zoom, increase the waterfall speed value, or hide the aggregate panel to return more workspace and render time to receiver cards.
No receivers found
- Choose USB Hardware, not Simulation or None.
- Verify WinUSB is bound to each RTL-SDR Interface 0.
- Press RESTART SDR in the header.
- Open the sidecar log from Settings or Receiver Setup and look for enumeration or driver errors.
Waiting for sidecar
Close other SDR software that may own the dongles, then use RESTART SDR. The radio sidecar shuts down with the app, self-terminates when the main process disappears, and stale sidecars are cleaned up at the next launch.
The scanner does not stop on signals
Confirm the selected range or Frequency Manager group contains valid channels, lower the dB-above-floor threshold, allow enough settle time, and review persistent lockouts. For array mode, confirm more than one non-ADS-B receiver is online.
IQ playback has no expected signal
Confirm the capture is cu8 or cf32 and keep its .sigmf-meta beside the data file so sample rate and centre frequency restore automatically.
A remote rtl_tcp receiver is offline
Confirm the remote process is listening on the configured interface and port, test the host from Windows, and allow the port through the remote firewall. SPECTER reconnects with backoff after connectivity returns.
SBS, Icecast, or rigctl will not connect
Verify the service is enabled, the configured port is available, and Windows Firewall allows the intended network profile. For Icecast, confirm the source credentials and mount path.
No audio
Open the Audio Mixer, start monitoring, verify the channel and master are not muted, raise squelch sensitivity if needed, and confirm the tuned mode and bandwidth match the signal.
Recording, Library, or report problem
Confirm free disk space and write access to Documents\SPECTER SDR\. Interrupted sessions remain visible in Library for recovery and review rather than disappearing.
Activation rejected
Confirm the key begins with SSDR-, internet access is available for initial activation, and the key is not already active on another computer. Use the support page for replacement-key help.
TinySA freezes above a 2000 MHz-wide span
Distinguish sweep width from tuned frequency. A 100 to 5300 MHz range is 5200 MHz wide. v1.7.39 fixes the autonomous-display pause/reply sequencing issue; v1.7.41 separately fixes atomic range application and stale range confirmation. Review the tinySA procedure and version availability.
Use Auto RBW as a baseline, allow a complete sweep, and compare narrower and wider spans. Record whether the problem changes when other radios are disconnected or a separate USB controller is used. That comparison is diagnostic, not proof of the cause.
Only CRITICAL is enabled, but many clips appear
Before v1.7.41, event clips could be saved for bursts that did not match an enabled class. v1.7.41 makes clip eligibility follow enabled classes, receiver permissions and thresholds, and the analyzer-alert switch. Existing old clips are not removed. Hiding popups alone is not the way to disable otherwise qualifying evidence. See Recording and alerts.
Activity watch or notification sound problems
Confirm ACTIVITY WATCH is on for the correct audio-capable radio, and check threshold, hold time, mode, and the chosen response switches. A busy signal present during background learning may not count as new activity. For sound, preview the specific tone, check the Windows output device, and remember that tones bypass the receiver master-volume control. Details: Channel Activity Watch.
Large logs and support evidence
In v1.7.41, Logs\sidecar.log is capped at 10 MB with one previous capped file, sidecar.log.1. The first write trims an oversized inherited current log to its newest 10 MB. This is bounded diagnostic storage, not a limit on recordings or the whole data folder.
Open the sidecar log in Settings or Receiver Setup. The viewer can include recent lines from the previous file; use COPY or OPEN FULL FILE as needed. Include installed version, device model, exact frequency range, RBW or sample rate, hub/controller arrangement, and the time of the failure in a private support ticket. With the default data folder the current file is Documents\SPECTER SDR\Logs\sidecar.log.
Never post license keys, passwords, or private connection details publicly. If using a custom data root, collect logs from that location instead.