Switch between multiple slices using the A..H tab row¶
The FLEX-8600 supports up to eight simultaneous receive slices. The A..H tab row at the top of the RX Controls applet lets you switch which slice the applet is bound to, so you can view and adjust each slice's mode, frequency, filter, and other settings independently.
Before you start¶
- AetherSDR must be connected to a FLEX-8600 radio. The RX Controls applet requires an active radio connection.
- The radio must have more than one slice active. The tab row is hidden when only one slice exists.
- The RX Controls applet must be visible. If it is not, click the RX tray button on the right sidebar to show it.
Steps¶
- Look at the top of the RX Controls applet for the horizontal row of lettered tabs (A, B, C, and so on, up to H).
- Click the tab letter that corresponds to the slice you want to inspect or control.
- Confirm the switch: the Slice badge in the header row updates to show the letter of the newly selected slice, coloured by its slice identity.
- All controls below the tab row — mode, frequency, filter, AGC, AF gain, and others — now reflect and control the selected slice.
What each control does¶
| Control | Behavior | Notes |
|---|---|---|
| Slice tabs (A..H) | Selects which slice the RX applet is bound to; emits sliceActivationRequested. | Row hidden if maxSlices <= 1. clearSliceButtons() tears down all generated tab buttons and restores the static slice badge on disconnect (v0.9.5.1, #2254). Slice button click connections are guarded against duplicate signal handlers across reconnects. |
| Slice badge | Displays the letter of the currently bound slice. | Coloured by slice identity. The text format is set to rich text to support HTML rendering of the slice letter if needed (Qt RichText, #2606). |
| 🔓 / 🔒 (tune lock) | Toggles tune-lock on the slice; locked slice ignores frequency changes. | Icon flips between open and closed padlock. |
| ANT1 (RX antenna) | Opens a menu listing available antennas; selecting sets slice->setRxAntenna, or routes to an assigned KiwiSDR receiver profile when a virtual antenna token is chosen. | Populated from the radio's antenna list plus any KiwiSDR virtual-antenna tokens from the Kiwi manager; blue-coloured label. Falls back to ANT1/ANT2 when the list is empty. |
| ANT1 (TX antenna) | Opens a menu listing TX-capable antennas; sets the slice's TX antenna. | Red-coloured label. RX-only antenna ports (prefix 'RX') are filtered out. When the radio has not yet reported its antenna list, a fallback heuristic accepts ports starting with 'ANT', 'TX', or 'XVTR'. |
| 2.7K (filter width) | Shows current filter bandwidth. | Updates when filter preset is applied or when the passband widget is dragged. |
| QSK | Lights amber when CW break-in (QSK) is active. | Read-only; controlled via the CW applet Breakin button. |
| TX (badge) | Click to set this slice as the TX slice (calls slice->setTxSlice). | |
| Mode combo | Sets slice mode; reshapes filter and step presets for the new mode. | RADE option requires HAVE_RADE build flag. DSTR and FreeDV modes are filtered out when the model doesn't support them. Selecting a real radio mode tears down a running WFM software-demod overlay (WFM itself is toggled from the VFO-flag WFM button, not this combo). CW-mode detection now uses the shared isCwMode() helper from VoiceModeGate so all CW variants (CW, CWR, etc.) share one mode-settings list instead of mode-specific ones. |
| WFM button | Toggles the software FM demodulator on this slice. When enabled, the slice's DAX IQ stream is routed through a Hi-Fi Cable for wideband FM demodulation. | Checkable button; green when active. Tooltip: "Software FM demodulator via DAX IQ → Hi-Fi Cable". Selecting any mode from the Mode combo automatically deactivates WFM on that slice. |
| Frequency label | Displays current VFO frequency with dotted grouping. | Click to switch into edit mode. |
| Frequency edit | Enter MHz and press Enter to tune and recenter; supports kHz/Hz auto-scaling. Escape cancels the entry, restores the previous frequency, and dismisses the editor (v0.9.0, #1954). | XVTR-aware: accepts up to 50,000 MHz when the slice is on an XVTR antenna. 3-digit band convenience: on 2m/70cm (100-999 MHz) a digit insertion formats 1446 as 144.6. |
| STEP | < / > or mousewheel cycles through per-mode step sizes; emits stepSizeChanged and stepSizeChangedByUser. | Step list depends on slice mode. |
| Filter width presets | Click to apply a preset filter width; right-click to save current width as a preset. | Buttons hidden for FM/NFM/DFM modes; presets are per-mode. The width readout (shared with VfoWidget via RxApplet::formatFilterWidth) uses mode-aware logic so SSB/digital modes display the correct labelled width (#2197). The stepFilterWidth() method walks the per-mode preset list for mode-correct widen/narrow (#2208). CW presets now include 500 Hz and 600 Hz widths in addition to the original 50/100/250/400 Hz (#2208). |
| Filter passband widget | Drag the lo/hi edges to adjust filter passband; emits filterChanged (lo, hi). | |
| Tone mode (FM) | Selects CTCSS tone mode on FM/NFM/DFM. | Visible only in FM family modes. |
| CTCSS tone value | Selects CTCSS tone frequency sent with transmit. Includes standard EIA/TIA-603 tones (67.0 Hz to 254.1 Hz), plus the interstitial 69.3 Hz tone and additional intermediate frequencies (159.8, 165.5, 171.3, 177.3, 183.5, 189.9, 196.6, 199.5 Hz) that lack standard designations and display by frequency only. | Enabled only when Tone mode = CTCSS TX. |
| Offset (FM) | Sets FM repeater offset frequency in MHz. | |
| − (offset down) | Sets repeater offset direction to 'down' (TX below RX). | |
| Simplex | Sets repeater offset direction to simplex (TX = RX). | Default setting. |
| + (offset up) | Sets repeater offset direction to 'up' (TX above RX). | |
| REV / XFC | For FM repeater operation, REV inverts the TX offset sign to work a reversed repeater pair. On backends that support a transmit-frequency check, the button relabels to XFC: pressing it holds the transmit frequency check for the duration of the press, and while held it briefly forces the radio toward the transmit frequency to confirm coverage. | The button toggles REV (checkable) normally, or becomes a momentary XFC down-button when the connected radio backend advertises hasTransmitFrequencyCheck. The held XFC is released on hide, deactivate, capability change, or disconnect. When the backend supports transmit-frequency check, the REV toggle is disabled (the button acts only as XFC). |
| 🔊 / 🔇 (mute) | Single-click mutes/unmutes this slice (deferred by the platform click-discrimination interval, configurable in Radio Setup → Slice Controls). Double-click mutes/unmutes all owned slices via muteAllToggled signal. Icon flips when the radio acknowledges via SliceModel::audioMuteChanged. | Per the Radio-Authoritative Settings Policy (#2489), mute state is NOT saved/restored on reconnect — the radio is the source of truth for audio mute. The single-click is deferred by clickDiscriminationIntervalMs() (configurable in Radio Setup → Slice Controls, default platform double-click interval ~400 ms, #3009) so a double-click can override it. The double-click handler is in eventFilter and cancels the single-click timer. |
| AF gain | Adjusts slice audio output gain; emits afGainChanged. | Shows tooltip displaying the current percentage value. |
| L / R pan | Pans slice audio between left (0) and right (100) channels. | Double-click resets to 50 (centre). Shows tooltip displaying "C" at centre, "L{offset}" for left pan, "R{offset}" for right pan. The slider fill anchors from the centre outward so the neutral position is visually clear. |
| SQL / AUTO | Three-way cycle button: each click steps Off → SQL (manual threshold) → AUTO (algorithm tracks the noise floor) → Off. In AUTO mode the button shows amber 'AUTO'; in manual mode green 'SQL'. Disabled (and auto-turned off) in RTTY and digital modes (DIGU, DIGL) where squelch would notch out FSK characters (#2504). | Manual and Auto both turn the radio squelch on. The auto-squelch algorithm lives in the panadapter; the level is the dB margin above the measured noise floor. Mirrored by an identical button in the VFO panel's Audio tab. |
| Squelch level | In Manual mode adjusts the squelch threshold (takes effect only when squelch is on). In AUTO mode sets the dB margin above the measured noise floor where the gate opens, persisted to AutoSqlMarginDb. | In Manual mode the level is radio-authoritative per-slice (not persisted); in Auto mode the margin is persisted. Disabled in RTTY and digital modes and in Off mode. Right-click the AGC threshold slider for AGC-T noise calibration. |
| AGC mode | Sets the slice AGC mode. | Hidden in FM family modes. |
| AGC threshold | Sets AGC threshold (or AGC off-level when AGC mode is Off). | Tooltip reflects which value is being adjusted. Right-click opens a 'Calibrate AGC-T against noise floor…' command that starts the AGC-T noise calibration dialog (disabled while a Kiwi replacement receive is active). |
| RIT | Toggles Receive Incremental Tuning on/off. | |
| RIT 0 | Zeroes the RIT offset. | |
| RIT offset | < / > or mousewheel adjusts RIT offset by 10 Hz steps. | |
| XIT | Toggles Transmit Incremental Tuning on/off. | |
| XIT 0 | Zeroes the XIT offset. | |
| XIT offset | < / > or mousewheel adjusts XIT offset by 10 Hz steps. |
Digital mode squelch behavior¶
Squelch is disabled in RTTY, DIGU, and DIGL modes. When you switch to any of these modes from a non-digital mode:
- The SQL toggle button and squelch level slider become disabled.
- If squelch was on before switching, AetherSDR saves the state and turns squelch off automatically.
- This prevents the squelch from gating weak FSK signals, which would otherwise notch out FSK characters and break decoding (#2504).
Switching away from a digital mode to a non-digital mode restores the previous squelch state.
Manual squelch level persistence¶
Squelch level is radio-authoritative. The manual squelch level is not persisted client-side; the radio preserves the per-slice squelch level across mode cycles and reconnects. AetherSDR does not seed or restore the manual level from application settings — the radio is the source of truth.
RADE mode behavior¶
RADE mode is a client-side only mode. When you select RADE from the Mode combo (available only in builds with the HAVE_RADE flag), the client immediately enters RADE mode and activates the RADE subsystem. The radio itself continues to report the underlying DIGU or DIGL mode.
Because RADE is client-side only, the following is important to understand:
- Mode switch away from RADE: When you switch away from RADE to another mode, the client deactivates RADE mode. The applet emits
radeActivated(false)only if the slice was actually in RADE mode, preventing stale deactivate signals when changing modes on a