Change mode from the VFO panel¶

Use the VFO panel's Mode tab to switch the demodulation mode for any slice — for example, from USB to CW or FM — without leaving the spectrum view.

Before you start¶

AetherSDR must be connected to the radio. The VFO panel requires an active radio connection.
The VFO panel must be open. If it is not visible, click the VFO marker flag on the spectrum display for the slice you want to change.

Steps¶

Click the VFO marker flag on the spectrum display for the target slice. The VFO panel opens, anchored to the left of the marker.
Click the Mode tab inside the VFO panel.
Click the Mode combo and select the desired mode from the list.

What each control does¶

Control	Default	Valid values
Mode combo	USB	USB, LSB, CW, CWL, AM, SAM, DIGU, DIGL, FM, NFM, DFM, RTTY
Filter preset buttons	—	Saved filter width presets
ADSP button (DSP tab)	Opens the AetherDSP Settings dialog (client-side NR2 / NR4 / DFNR / RN2 / BNR / MNR). Same entry point as the Settings menu (v0.9.8).	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 (v0.9.8).	Spans 2 columns in the 4-column DSP grid. Matches the existing menu / chain entry points for the strip.
RX antenna button	—	Opens antenna selection menu for the receive antenna of this slice.
TX antenna button	—	Opens antenna selection menu for the transmit antenna of this slice.
Frequency display	—	Shows the current slice frequency. Click once to begin direct frequency entry; type MHz and press Enter or Tab.
Filter width label	—	Shows current filter bandwidth. Click to cycle through filter preset buttons. Uses RxApplet::formatFilterWidth.
AF Gain slider (Audio tab)	100	0-100. Sets the audio output level for this slice.
Pan slider (Audio tab)	50	0-100. Sets left/right stereo pan for this slice. 50 = centre.
Mute button (Audio tab)	off	Toggle. Mutes audio output for this slice without changing the AF gain setting.
Squelch button + slider (Audio tab)	off	0-100. Enables squelch for this slice. The adjacent slider sets the threshold.
AGC combo (Audio tab)	FAST	FAST, MED, SLOW, OFF. Sets the AGC attack/release speed for this slice.
RIT / XIT buttons + labels (X/RIT tab)	off	Toggle. Enables receiver (RIT) or transmitter (XIT) incremental tuning. Scroll-wheel adjusts in 10 Hz steps.
DAX channel combo (DAX tab)	Off	Off, 1-8. Assigns a DAX audio channel to this slice.
Marker thickness button	1 px	Off, 1 px, 3 px. Cycles the VFO marker line thickness. Persisted per slice.
Filter edges button	shown	Toggle. Hides or shows the filter edge lines on the spectrum passband. Persisted per slice.
Collapse toggle	expanded	Toggle. Collapses the VFO panel to a compact frequency-only strip. Persisted per slice.

Mode combo — sets the demodulation mode for the slice. Selecting a new mode takes effect immediately on the radio.

Filter preset buttons — appear on the same Mode tab. Each button applies a saved filter width. Right-click a button to save the current filter width into that slot. Presets are persisted in FilterPresets.

Filter width label — shows the current filter bandwidth. Click it to cycle through the filter preset buttons on the Mode tab. Uses RxApplet::formatFilterWidth as the single source of truth, fixing a 0.1 kHz offset that affected SSB/digital mode readouts (#2197, v0.9.8).

RX antenna button — opens a menu listing available receive antennas. The menu items display human-readable labels for each antenna. Antenna selection is based on the internal antenna key, not the displayed text. If the radio provides a per-slice antenna list, that list is used instead of the global antenna list.

TX antenna button — opens a menu listing available transmit antennas. The menu automatically excludes RX-only antenna ports (those starting with "RX"). The menu items display human-readable labels for each antenna. Antenna selection is based on the internal antenna key, not the displayed text. If the radio provides a per-slice antenna list, that list is used instead of the global antenna list.

Frequency display — shows the current slice frequency. Click once to begin direct frequency entry. Type the frequency in MHz and press Enter or Tab.

On transverter bands (frequency above 100 MHz), the entry logic accepts frequencies up to 50,000 MHz.
If you explicitly enter a frequency above 54.0 MHz with an MHz format (e.g., "145.000"), the parser treats it as an intentional MHz entry and accepts frequencies up to 50,000 MHz.
For three-digit bands (100-999 MHz), a bare integer of 4 or more digits automatically inserts a decimal after the third digit (e.g., 1446 becomes 144.6 MHz).
On other bands, the maximum entered frequency is 54.0 MHz. Values above 54000 are treated as Hz, and values between 54 and 54000 are treated as kHz.

The tab bar now uses clickable QPushButton controls with keyboard focus support. Tab labels are keyboard-navigable using Tab and Shift+Tab.

Press Tab to move focus to the next tab button, Shift+Tab to move to the previous one.
Press Enter or Space to activate the focused tab.
A focus indicator (underline) appears on the currently focused tab button.

Right-click the Audio tab (speaker icon) to toggle mute for the current slice directly, without switching to the Audio tab.

Mouse wheel frequency tuning (v26.6.3)¶

The mouse wheel direction for frequency tuning now respects the Reverse mouse wheel setting in InteractionSettings. When enabled, scrolling up decreases the frequency and scrolling down increases it. This setting applies globally.

Frequency display accessibility (v26.6.3)¶

The frequency display now provides accessibility events (value change) when the frequency changes, using a debounced timer to avoid chatter. Screen readers and accessibility tools receive the updated frequency text without flooding the accessibility system.

DSP tab controls¶

The DSP tab shows buttons for noise reduction and filtering algorithms supplied directly by the radio, plus client-side launcher buttons. The following buttons are available:

Button	Description
NR	Noise reduction
NB	Noise blanker
ANF	Automatic notch filter
APF	Audio peak filter (visible in CW mode only)
NRL	Noise reduction level
NRS	Spectral subtraction
RNN	RNN noise reduction
NRF	Spectral noise filter
ANFL	LMS notch filter
ANFT	FFT notch filter
NR2	Opens the NR2 algorithm in the AetherDSP Settings dialog (right-click)
NR4	Opens the NR4 algorithm in the AetherDSP Settings dialog (right-click)
MNR	Opens the MNR algorithm in the AetherDSP Settings dialog (right-click)
DFNR	Opens the DFNR algorithm in the AetherDSP Settings dialog (right-click)
BNR	Opens the BNR algorithm in the AetherDSP Settings dialog (right-click)
RN2	Opens the RN2 algorithm in the AetherDSP Settings dialog (right-click)
ADSP	Opens the AetherDSP Settings dialog (same entry point as the Settings menu)
AetherVoice	Toggles the Aetherial Audio Channel Strip — the unified TX/RX DSP suite

All radio-side buttons default to off and toggle the corresponding algorithm on or off for the active slice.

Note: The client-side noise reduction modules NR2, NR4, MNR, BNR, DFNR, and RN2 are accessible via right-click on the DSP tab to open the AetherDSP Settings dialog, or from the spectrum overlay menu and the AetherDSP applet.

DSP level slider¶

When one or more leveled DSP algorithms (NR, NB, ANF, NRL, NRS, NRF, or ANFL) are active, a level slider appears below the DSP button grid. The slider label shows which algorithm is currently targeted — the most recently enabled leveled DSP. The numeric value is displayed to the right of the slider.

Range: 0–100.
The slider retargets automatically when you enable a different leveled DSP button.
When no leveled DSP is active, or when only RNN, ANFT, or APF is on, the slider row fades out. It remains in the layout at all times to prevent the button grid from shifting.
On launch, any DSP enabled in the radio's saved profile now properly shows the level slider without requiring manual toggling (#startup-slider, v0.9.8).

Pan slider center-mark behavior (v26.6.1)¶

The Pan slider in the Audio tab now paints a fill gradient that anchors from the centre outward. When the slider is at the midpoint (50), the groove is fully filled with background colour. When moved left or right, the accent colour fills the region between centre and the handle position. A small centre-mark dot appears on the groove to indicate the neutral position.

Squelch behavior by mode¶

The squelch button and slider in the Audio tab are automatically disabled in certain modes where squelch is not meaningful:

Digital modes (DIGU, DIGL) — Audio feeds external decoders via DAX. Squelch is disabled.
RTTY mode — Like digital modes, audio feeds external decoders. Squelch is disabled to prevent gating weak FSK signals (#2504, v26.5.1).
CW mode — The radio locks squelch on at a fixed level and rejects changes. Squelch is disabled.

When squelch is disabled and was previously enabled, it is automatically turned off to avoid a stuck squelch state. The m_savedSquelchOn flag preserves the previous state so it can be restored when switching back to a voice mode.

Locked slice behavior¶

When a slice is locked using the lock button on the VFO panel:

Scrolling the mouse wheel over the VFO panel does not change frequency. Instead, the lock state is acknowledged with visual feedback.
Attempting to begin direct frequency entry on a locked slice is blocked. Any in-progress direct entry is cancelled.
The frequency display shows a locked indicator overlay.
Unlocking the slice clears the locked overlay and restores normal tuning behavior.

VFO panel height behavior¶

The VFO panel dynamically adjusts its height to match the currently visible tab. When the DSP tab is taller than the Mode tab (for example, when digital sub-mode controls are visible in DIGU/DIGL), the panel height now correctly matches only the current tab to avoid unwanted gaps.

VFO panel theming (v26.6.1)¶

The VFO panel now uses its own theming surface under the spectrum/vfo container scope. This allows theme overrides to target the VFO panel independently from the spectrum display. The panel paints its background, signal meter, and badge elements using ThemeManager::color() tokens:

color.background.0, color.background.1, color.background.2
color.text.primary, color.text.label
color.accent, color.accent.bright

The ADSP and AetherVoice buttons now use themed colours for their pressed state (color.accent) and background (color.background.1) instead of hard-coded values.

Tips¶

Changing mode may alter the active filter passband. Check the filter width label in the header row after switching modes, and apply a filter preset if needed.
The filter width label in the VFO panel header shows the current bandwidth. Click it to cycle through the filter preset buttons on the Mode tab.
To access NR2, NR4, MNR, BNR, DFNR, or RN2, right-click the DSP tab button for that algorithm, or right-click the spectrum display and open the overlay menu, or open the AetherDSP applet.
The marker thickness and filter edges buttons are persisted per slice in Slice{N}_MarkerWidth and Slice{N}_FilterEdgesHidden settings keys.
Press the collapse toggle next to the frequency display to reduce the panel to a compact frequency-only strip. The state is persisted per slice.
Right-click the Audio tab (speaker icon) to quickly toggle mute without switching tabs.
Enable Reverse mouse wheel in InteractionSettings to invert the frequency tuning direction.

[Apply a filter width preset from the VFO panel](apply-a-filter-width-preset-from-the-vfo-p