Enable squelch from the VFO panel¶
Squelch mutes audio for a slice when the received signal falls below a set threshold. Use this to silence background noise on FM, AM, or digital modes when no signal is present.
Before you start¶
- AetherSDR must be connected to a FLEX-8600 radio.
- The VFO panel for the target slice must be open. If it is not, click the VFO marker flag on the spectrum display for that slice.
- If the VFO panel is collapsed to the frequency-only strip, click it once to expand it.
Steps¶
- Open the VFO panel by clicking the VFO marker flag on the spectrum display for the slice you want to configure.
- Click the Audio tab inside the VFO panel.
- Click the Squelch button to enable squelch. The button activates and squelch is applied to the slice immediately.
- Drag the adjacent squelch slider left or right to set the threshold. The valid range is 0–100.
To disable squelch, click the Squelch button again.
What each control does¶
| Control | Default | Valid range |
|---|---|---|
| RX antenna button | Radio default | Radio antenna list |
| TX antenna button | Radio default | Radio antenna list (RX-only ports excluded) |
| Frequency display | Current slice frequency | 0.001–50000 MHz |
| Filter width label | Current filter bandwidth | Per mode filter presets |
| AF Gain slider (Audio tab) | 100 | 0–100 |
| Pan slider (Audio tab) | 50 | 0–100 |
| Mute button (Audio tab) | Off | On / Off |
| Squelch button (Audio tab) | Off | On / Off |
| Squelch slider (Audio tab) | — | 0–100 |
| AGC combo (Audio tab) | FAST | FAST / MED / SLOW / OFF |
| Mode combo (Mode tab) | USB | USB / LSB / CW / CWL / AM / SAM / DIGU / DIGL / FM / NFM / DFM / RTTY |
| Filter preset buttons (Mode tab) | — | Per saved preset |
| RIT / XIT buttons (X/RIT tab) | Off | On / Off |
| DAX channel combo (DAX tab) | Off | Off / 1–8 |
| Marker thickness button | 1 px | Off / 1 px / 3 px |
| Filter edges button | Shown | On / Off |
| Collapse toggle | Expanded | On / Off |
| ADSP button (DSP tab) | Opens the AetherDSP Settings dialog (client-side NR2 / NR4 / DFNR / RN2 / BNR / MNR). Same entry point as the Settings menu. | Styled like a radio-side DSP toggle but non-checkable. Click raises and focuses the modeless AetherDSP Settings dialog. |
| AetherVoice button (DSP tab) | Toggles the Aetherial Audio Channel Strip — the unified TX/RX DSP suite. | Spans 2 columns in the 4-column DSP grid. Matches the existing menu / chain entry points for the strip. |
| NR / NR2 / RN2 / NR4 / MNR / DFNR / BNR / NRL / NRS / RNN / NRF buttons (DSP tab) | Off | On / Off. Right-click NR2, NR4, MNR, or DFNR to open the AetherDSP Settings dialog for that algorithm. |
Neither the button state nor the slider position is persisted as an AetherSDR AppSettings key — both reflect live radio state.
Tips¶
- Set the slider just above the noise floor to prevent the audio from cutting in and out on weak signals.
- The squelch threshold interacts with the AGC setting. If you change the AGC mode using the AGC combo, you may need to readjust the squelch slider.
DSP tab changes in v0.9.8¶
The DSP tab of the VFO panel received two new launcher buttons in v0.9.8:
| New button | Behavior |
|---|---|
| ADSP button | Opens the AetherDSP Settings dialog (client-side NR2 / NR4 / DFNR / RN2 / BNR / MNR). Same entry point as the Settings menu. Non-checkable button styled like a radio-side DSP toggle. |
| AetherVoice button | Toggles the Aetherial Audio Channel Strip — the unified TX/RX DSP suite. Spans 2 columns in the 4-column DSP grid. Non-checkable button. |
Both buttons are placed at the end of the DSP button grid. ADSP occupies 1 column, and AetherVoice occupies the adjacent 2 columns.
Startup DSP level synchronization¶
In v0.9.8, the DSP level slider synchronization was improved. When radio-side DSP buttons (NR, NB, ANF, NRL, NRS, NRF, ANFL) are enabled in the radio's saved profile, the corresponding DSP level slider is now pushed onto the shared level stack at startup. Previously, the level slider was missing until the user manually toggled the DSP button. This fixes issue #startup-slider.
DSP level slider¶
A shared DSP level slider row appears below the DSP button grid. The slider targets whichever leveled DSP button was most recently turned on. The label to the left of the slider shows the active target (for example, NR or NB). The numeric value is shown to the right.
The slider row is always present in the layout. When no leveled DSP is active — or when only RNN, ANFT, or APF is on — the row fades out and does not respond to interaction. It becomes fully visible again as soon as a compatible DSP button is enabled.
Leveled DSP targets supported by the slider:
| Target | Controlled by |
|---|---|
| NR | setNrLevel |
| NB | setNbLevel |
| ANF | setAnfLevel |
| NRL | setNrlLevel |
| NRS | setNrsLevel |
| NRF | setNrfLevel |
| ANFL | setAnflLevel |
The slider range is 0–100. The level value is not persisted as an AetherSDR AppSettings key — it reflects live radio state.
Filter width label fix in v0.9.8¶
The Filter width label in the VFO panel now uses RxApplet::formatFilterWidth as its single source of truth. This fixes a 0.1 kHz offset that previously affected SSB and digital mode filter readouts (issues #794, #1225, #2197). The label now stays in sync with the RX applet's filter display.
Squelch behavior for RTTY mode (v26.5.1)¶
Starting in v26.5.1, squelch is also disabled when the slice is set to RTTY mode. This change addresses issue #2504, where squelch was gating weak FSK signals used by external decoders via DAX. The squelch button and slider are automatically disabled when RTTY mode is active, matching the existing behavior for digital and CW modes.
If squelch was enabled when switching to RTTY mode, AetherSDR saves the squelch state and restores it when you switch back to a voice or FM mode.
Antenna selection changes in v26.5.2.1¶
Starting in v26.5.2.1, the RX and TX antenna selection menus in the VFO panel have been improved:
| Change | Description |
|---|---|
| RX antenna menu | Now uses the slice's rxAntennaList() when available, falling back to the radio's master antenna list. Each menu item stores the antenna name as data, and the item text is generated by antennaMenuLabel() for consistent formatting. |
| TX antenna menu | Uses the txAntennaOptions() method to build the list, which automatically excludes RX-only antenna ports. Antennas with names starting with "RX" are filtered out. The likelyTxAntennaFallbackToken() helper determines which antennas are likely TX-capable when a dedicated TX antenna list is not available. |
| Tooltip and status tip | Each menu item now shows the raw antenna name as a tooltip and status tip, providing full name visibility when the formatted label is truncated. |
TX antenna filtering logic¶
The TX antenna menu uses the following logic to determine which antennas to show:
- If a dedicated TX antenna list is available from the radio, use it directly.
- Otherwise, filter the master antenna list to exclude ports that start with "RX".
- The
likelyTxAntennaFallbackToken()helper identifies TX-capable antennas by checking if they start with "ANT", "TX", or equal "XVTR".
Frequency entry changes in v26.5.2.1¶
The frequency entry logic for XVTR bands has been updated in v26.5.2.1:
| Change | Description |
|---|---|
| Maximum frequency limit | Increased from 450 MHz to 50000 MHz to support microwave bands. |
| 3-digit band convenience | The automatic decimal insertion (e.g., 1446 → 144.6) now only applies when the slice is in a 100–999 MHz band. For 23cm and higher bands, a bare integer is interpreted as the full MHz value (e.g., 1296 means 1296 MHz, not 129.6 MHz). |
Frequency entry rules for XVTR bands¶
When entering frequencies on XVTR bands:
- 100–999 MHz band: Enter a bare integer with at least 4 digits to have the decimal automatically inserted after the 3rd digit (e.g., 144600 → 144.600, 14696 → 146.96).
- 1000 MHz and above: Enter the full MHz value directly (e.g., 1296 for 23cm means 1296.000 MHz).
- You can always enter a decimal point manually to bypass the automatic insertion.
Frequency entry changes in v26.5.3¶
The frequency entry logic has been updated to support explicit MHz entry on high bands:
| Change | Description |
|---|---|
| Explicit MHz entry | When a frequency value greater than 54.0 is entered with an explicit decimal point (e.g., "144.200"), it is now treated as MHz and accepted for any band, including non-XVTR bands. Previously, entering "144.200" on a non-XVTR band would be rejected as out of range. |
| Normalized parsing | The text is now normalized using FrequencyEntryParser::normalizedMhzText() which handles "14.225.000" format by removing dots beyond the first. |
| Range validation | The maximum frequency limit of 50000 MHz applies to all bands when an explicit decimal point is used, matching the existing behavior for XVTR bands. |
Frequency entry rules in v26.5.3¶
When entering frequencies:
-
Explicit MHz entry: Enter a frequency with a decimal point (e.g., "14.225", "144.200", "1296.000") to have it treated as MHz directly. Values above 54.0 MHz are accepted when an explicit decimal point is present.
-
Bare integer entry (non-XVTR bands, below or equal to 54.0 MHz): Enter a bare integer to be parsed as follows:
- Values below 54000: Treated as kHz (e.g., 14225 = 14.225 MHz)
-
Values above 54000: Treated as Hz (e.g., 14225000 = 14.225 MHz)
-
Bare integer entry (XVTR bands, above 54.0 MHz): A bare integer is treated as MHz directly, with the 3-digit band convenience rule applied for 100–999 MHz bands.
Locked slice behavior in v26.5.3¶
Starting in v26.5.3, when a slice is locked, the following behaviors apply:
| Behavior | Description |
|---|---|
| Tune blocked notification | When you attempt to scroll the mouse wheel over a locked slice, a visual LOCKED overlay is shown on the frequency display to indicate that tuning is blocked. |
| Direct entry cancel | If you begin direct frequency entry (click the frequency display) on a locked slice, the entry is automatically cancelled and the LOCKED overlay is shown. |
| Lock/unlock button | The lock/unlock button updates immediately when the slice lock state changes. Unlocking clears the LOCKED overlay. |
VFO panel tab height fix in v26.5.3¶
In v26.5.3, the VFO panel tab content now uses a custom stacked widget that reports only the current tab's preferred size. This fixes a layout issue where the tab content area could over-allocate height when switching between tabs of different heights (e.g., switching from DSP tab, which shows additional controls for DIGU/DIGL modes, to Mode tab). The tab content area now fits each tab's content properly without leaving gaps.
Scrolling behavior in v26.5.3¶
In v26.5.3, the mouse wheel scrolling behavior has been updated:
| Change | Description |
|---|---|
| Locked slice handling | When scrolling over a locked slice in collapsed mode, the tune request is now blocked with a visual LOCKED notification instead of being silently ignored. |
| Consistent collapsed mode | The scroll behavior is now consistent between expanded and collapsed modes. |
Changes in v26.6.3¶
Tab bar improvements¶
In v26.6.3, the VFO panel tab bar was rewritten to use QPushButton instead of QLabel for tab labels. This change provides better accessibility support:
| Change | Description |
|---|---|
| Tab buttons | Each tab label is now a QPushButton with checkable behavior. Tab focus is enabled via `Qt:: |