TNF (Tracking Notch Filters)

TNF (Tracking Notch Filters)

Tracking Notch Filters remove persistent interfering signals from the audio passband.

Creating a TNF

• Right-click on the spectrum or waterfall → Add TNF at XX.XXX MHz
• Or click +TNF in the left sidebar (creates TNF at filter center)
• TNF appears as a yellow shaded region on the spectrum and waterfall

Managing TNFs

Move

• Click and drag the TNF marker to reposition

Adjust Width/Depth

• Right-click the TNF marker → adjust Width (Hz) and Depth (1-3)

Make Permanent

• Right-click → Make Permanent — TNF persists across radio power cycles
• Permanent TNFs display in green; temporary TNFs in yellow

Remove

• Right-click → Remove TNF
• TNFs are removed optimistically (no radio status confirmation)

Permanent vs Temporary

Type	Color	Survives Reboot	Default
Temporary	Yellow	No	Yes
Permanent	Green	Yes	No

Known Issues

• Sending tnf set immediately after tnf remove can crash the radio (issue #69, fixed with race guard)
• TNF removal and permanent status changes are optimistic updates — the radio doesn't send status confirmation for these commands