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Audio/SDR Configuration Fix Tool

EAS Station™ includes a built-in diagnostic page that detects and repairs the most common sample-rate misconfiguration in SDR setups: an audio sample rate accidentally stored where an IQ (RF) sample rate belongs, or vice versa. The page lives at /admin/audio-sdr-fix, reachable from Settings → Audio/SDR Fix (/settings). It requires the system.configure permission.

When to Use It

Use this tool when you see any of these symptoms after configuring receivers or audio sources:

Symptom Likely Cause
MP3 streams never appear as Icecast mount points Audio source sample rate far too low
Waterfall display shows the wrong frequency scale (kHz instead of MHz) Receiver IQ rate set to an audio-rate value
High-pitched squeal or tone on SDR audio Sample-rate mismatch between IQ capture and audio output

The shared root cause is a sample rate of the wrong magnitude — e.g. 48000 (an audio rate) stored as a receiver's IQ rate, which should be in the millions of Hz.

What the Diagnosis Checks

Clicking Run Diagnosis calls GET /api/admin/audio-sdr-fix/diagnose, which scans only enabled receivers and audio sources:

Check Flagged when Recommended value
SDR receiver IQ sample rate Below 100,000 Hz 2,500,000 Hz (2.5 MHz) for Airspy drivers; 2,400,000 Hz (2.4 MHz) for RTL-SDR and others
HTTP stream audio source sample rate Below 32,000 Hz 48,000 Hz
SDR audio source output sample rate Below 20,000 Hz 48,000 Hz

The results panel shows a summary (receiver count, audio source count, issues, warnings) and a per-item card for every configuration, including frequency, modulation, and current rates, with each problem marked in red alongside its recommended replacement.

Airspy R2 hardware only supports 2.5 MHz and 10 MHz IQ rates, which is why the tool picks 2.5 MHz when the receiver driver contains "airspy".

Applying Fixes

If issues were found, the Step 2: Apply Fixes panel lists exactly what will change. Clicking Apply Fixes calls POST /api/admin/audio-sdr-fix/apply with {"auto_fix": true} and performs these database updates in one transaction:

  1. Receivers — every enabled receiver with an IQ rate below 100 kHz is set to 2.5 MHz (Airspy) or 2.4 MHz (other drivers).
  2. HTTP stream sources — every enabled stream source with an audio rate below 32 kHz is set to 48 kHz.
  3. SDR audio sources — every enabled sdr source with an audio output rate below 20 kHz is set to 48 kHz.

The response lists each change with old and new values, and the page automatically re-runs the diagnosis so you can confirm everything now reads OK.

Note: Apply Fixes updates all matching configurations at once — there is no per-item selection. Review the fix list before confirming. The changes only touch sample-rate fields; frequencies, gains, and other settings are untouched.

Restarting the SDR Service

The new sample rates are stored in the database but the running SDR service keeps using its old values until restarted. The tool's Step 3 panel has a Restart SDR Service Now button (POST /api/admin/audio-sdr-fix/restart-service) that restarts the unit via systemctl. If the automatic restart fails (e.g., sudo rights are missing), the response includes the command to run manually on the host:

sudo systemctl restart eas-station-sdr.service

After the restart, verify:

  • Icecast mount points are listed (default http://<host>:8000/)
  • The waterfall display (/admin/radio) shows the correct MHz frequency scale
  • Streams play clear audio with no squeal

Routes Reference

Method Route Purpose
GET /admin/audio-sdr-fix Diagnostic page (HTML)
GET /api/admin/audio-sdr-fix/diagnose Scan enabled receivers/sources, return issues as JSON
POST /api/admin/audio-sdr-fix/apply Apply the fixes described above ({"auto_fix": true})
POST /api/admin/audio-sdr-fix/restart-service Restarts the SDR service via systemctl (returns the manual command if the restart fails)

All routes require a logged-in session (the application's deny-by-default guard); the POST endpoints additionally require the standard CSRF header when called outside the page.

If Problems Persist

  • Work through the SDR Master Troubleshooting Guide for hardware detection, driver, and gain issues — this tool only corrects sample rates.
  • Check the SDR service logs: journalctl -u eas-station-sdr.service -n 100.
  • Verify Icecast itself is healthy via /api/health/icecast (see Health Monitoring Endpoints).
Back to Documentation Index

This document is served from docs/troubleshooting/AUDIO_SDR_FIX_TOOL.md in the EAS Station™ installation.