Adjust S-History marker lifetime, QRM gate and edge threshold¶
Fine-tune how Signal History markers behave on the panadapter — how long they live, how persistently a signal must hold to be flagged as QRM, and how aggressively the marker edge snaps to the carrier.
Before you start¶
- Open SpotHub:
Settings > SpotHub... - Click the Display tab.
Steps¶
-
Under Signal History, adjust Marker Lifetime: by dragging the slider. Inactive markers are removed after this many seconds (range 15–300 sec, default 60). Left double-click the slider to reset to 60.
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Adjust QRM Gate: — the seconds a narrow carrier or wideband signal must persist before the system classifies it as QRM (range 3–30 sec, default 6). Left double-click the slider to reset to 6.
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Adjust Edge Threshold: — the dB level above the noise floor for the slope-edge walk that refines a marker's carrier-side edge. A lower value hugs the carrier more tightly but is more noise-sensitive (range 1.0–10.0 dB, default 3.0). Left double-click the slider to reset to 3.0.
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Optionally enable Snap to Step: in the Signal History section to round click-to-tune to the nearest active slice step size.
What each control does¶
| Control | Label on slider | Default | Valid range | Setting key | Notes |
|---|---|---|---|---|---|
| Marker Lifetime: | 15 sec – 300 sec |
60 | 15–300 sec | SHistoryLifetimeS |
Left double-click resets to 60 |
| QRM Gate: | 3 sec – 30 sec |
6 | 3–30 sec | SHistoryQrmGateS |
Left double-click resets to 6 |
| Edge Threshold: | 1.0 dB – 10.0 dB |
3.0 | 1.0–10.0 dB | SHistorySoftEdgeDb |
Left double-click resets to 3.0 |
| Snap to Step: | toggle button | Disabled | Enabled / Disabled | SHistorySnapToStep |
Toggle always shows "Enabled" label — the text does not change to "Disabled" when toggled off |
Tips¶
- Marker Lifetime controls voice-bandwidth signal markers (gold by default). QRM markers (red by default) also follow this lifetime — they are not separately timed.
- To see Signal History markers on the panadapter in the first place, enable Signals and/or QRM under the top toggle row in the Display tab. Their persisted keys are
SHistoryMarkersEnabledandSHistoryQrmEnabled. - Turning on Snap to Step hides the small carrier offset that can appear when clicking an S-History marker; the tune frequency snaps to the next multiple of the active slice's step size.
- Left double-clicking any slider resets it to its default value, providing a quick way to restore factory behavior without dragging.
- The Snap to Step toggle button always displays "Enabled" regardless of its state. The current state is indicated by whether the button is visually pressed (checked) or not.
Troubleshooting¶
- Markers disappear too quickly — Increase Marker Lifetime: to a higher value. Left double-click the slider to reset to the 60-second default.
- QRM markers appear on weak signals that aren't really interference — Raise QRM Gate: so the system requires a longer hold time before classifying the signal as QRM. Left double-click the slider to reset to the 6-second default.
- Marker edges wobble or jump — Increase Edge Threshold: slightly (e.g., from 3.0 to 4.0 dB) to reduce noise sensitivity. Left double-click the slider to reset to the 3.0 dB default.