Advanced Transmitter Settings
The advanced settings panel (Show advanced transmitter settings in the RF Signal section) exposes fifteen parameters that define the transmitter's imperfections. Radio Presets fill all of them at once; manual edits are possible afterwards.
| Setting | Default | Range | Effect |
|---|---|---|---|
| Final drive (dB) | 0.0 | -40 to 40 | Extra drive into the power amplifier. Positive values push the amplifier toward compression and distortion. |
| PA headroom (dB) | 12.0 | 0.1 to 40 | How far below amplifier saturation the nominal signal sits. Small headroom means the signal clips early. |
| Compressor (dB) | 1.5 | 0 to 30 | Audio compression before modulation. Raises average loudness at the cost of naturalness. |
| PA softness | 2.8 | 0.5 to 10 | Shape of the amplifier limiting curve. Low values clip abruptly (harsh distortion), high values limit gently. |
| AM/PM (deg) | 6.0 | 0 to 45 | Phase shift that accompanies amplitude compression. Adds splatter and roughness when the amplifier is driven hard. |
| Carrier leak (dB) | 60.0 | 0 to 120 | Suppression of the residual carrier in suppressed-carrier modes. Higher is cleaner. |
| Sideband sup. (dB) | 60.0 | 0 to 120 | Suppression of the unwanted sideband in SSB. Higher is cleaner. |
| Freq error (Hz) | 0.0 | -10000 to 10000 | Static frequency offset of the transmitter oscillator. |
| Hum level (dB) | 120.0 | 0 to 120 | Mains hum suppression; 120 means no audible hum. Lower values add hum at the hum frequency. |
| Hum freq (Hz) | 0.0 | 0 to 400 | Mains hum fundamental (typically 50 or 100, or 60 or 120). Zero disables. |
| AM index | 0.85 | 0 to 1.2 | AM modulation depth. Above 1.0 is overmodulation with distortion and splatter. |
| PA sag (dB) | 0.0 | 0 to 30 | Supply voltage sag under load; produces a power dip on voice peaks and key-down. |
| TX noise (dB) | 120.0 | 0 to 160 | Broadband transmitted noise floor suppression. Higher is cleaner. |
| Phase noise (dB) | 120.0 | 0 to 160 | Oscillator phase noise suppression. Higher is cleaner; low values smear the signal spectrally. |
| CW rise (ms) | 5.0 | 0 to 50 | CW keying envelope rise time. Very short values cause key clicks. |
Other bounds: frequency must be positive, power must be at least 0 W, and the duty cycle used by the amplifier model runs from 0 to 1 with a default of 0.5.
The suppression-style values (carrier leak, sideband suppression, hum level, TX noise, phase noise) are expressed as decibels below the wanted signal, so larger numbers always mean a cleaner transmitter.