TEF6686-inspired adaptive FM bandwidth plugin for SDR#
Adaptive WFM bandwidth control designed especially for FM-DXing with Airspy HF+ receivers and SDR#.
- ✅ Adaptive FM bandwidth control
- ✅ SNR-driven Auto BW engine
- ✅ Stereo pilot aware filtering
- ✅ Smart stereo stability logic
- ✅ Stereo aware BW ON/OFF
- ✅ Pilot flicker protection
- ✅ Adjustable Attack / Release behavior
- ✅ Min / Max bandwidth limits
- ✅ FM-DX optimized profiles
- ✅ Adjacent channel protection
- ✅ Bandwidth hold damping
- ✅ Persistent settings
- ✅ Auto restore previous state
- ✅ Profile restore
- ✅ Manual BW restore
- ✅ Adjacent/Hold restore
- ✅ WFM-only safe mode
- ✅ Manual override controls
- ✅ Lightweight SDR# native UI
| Profile | Purpose |
|---|---|
| Es DX | Aggressive adaptive behavior for Sporadic-E |
| Tropo | Stable long-duration enhancement behavior |
| RDS Logging | Optimized for weak PI/RDS decoding |
| Hi-Fi | Wider bandwidth for listening quality |
Traditional SDR FM listening uses a fixed WFM filter width.
During real FM-DX conditions:
- signal strength changes rapidly
- adjacent channel interference changes constantly
- stereo/mono transitions happen dynamically
TEF6686 tuners became popular among FM DXers because their adaptive bandwidth behavior reacts automatically to changing RF conditions.
This plugin brings similar concepts into SDR#.
The current alpha uses:
- Visual SNR
- Stereo pilot detection
- Attack / Release smoothing
- Adjustable bandwidth limits
- FM-DX behavior profiles
Stereo signals may automatically allow slightly wider bandwidth, while weak mono signals can force narrower filtering for improved DX performance.
- SDR# Studio
- Windows
- SDR# Plugin API support
Recommended SDRs:
- Airspy HF+
- Airspy HF+ Discovery
- Airspy Mini
🚧 Early Alpha Release
Algorithms and behavior will continue evolving through real-world FM-DX testing during Es and tropo conditions.
- Adjacent channel intelligence
- Spectrum-aware adaptive filtering
- Advanced damping logic
- Preset saving
- Per-profile custom settings
- Optional logging/debug mode
Inspired by:
- TEF6686 adaptive bandwidth behavior
- FM-DX community experimentation
- Sjef Verhoeven (PE5PVB)
- Airspy SDR ecosystem by prog_
Experimental software intended primarily for FM-DX hobby use.