feat: Management of multiple slices on Flexradio

app.go

@@ -8270,6 +8270,22 @@ func (a *App) FlexSetSplit(on bool) error {
 	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetSplit(on) })
 }
 
+// FlexSetActiveSlice focuses a slice (A/B/C/D…) so all commands target it.
+func (a *App) FlexSetActiveSlice(idx int) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetActiveSlice(idx) })
+}
+
+// FlexSetTXSlice makes a slice the transmitter (e.g. TX on the active slice).
+func (a *App) FlexSetTXSlice(idx int) error {
+	if a.cat == nil {
+		return fmt.Errorf("cat not initialized")
+	}
+	return a.cat.FlexDo(func(fc cat.FlexController) error { return fc.SetTXSlice(idx) })
+}
+
 // keyFlexBandAnt stores the per-band RX/TX antenna map (global, machine-local).
 const keyFlexBandAnt = "flex.band_antennas"
 

frontend/src/components/FlexPanel.tsx

@@ -5,7 +5,7 @@ import {
   FlexSetProcessor, FlexSetProcessorLevel, FlexSetMon, FlexSetMonLevel, FlexSetMic,
   FlexMox, FlexAmpOperate,
   GetPGXLStatus, PGXLSetFanMode,
-  FlexSetAGCMode, FlexSetAGCThreshold, FlexSetAudioLevel, FlexSetMute, FlexSetRXAntenna, FlexSetTXAntenna, FlexSetSplit,
+  FlexSetAGCMode, FlexSetAGCThreshold, FlexSetAudioLevel, FlexSetMute, FlexSetRXAntenna, FlexSetTXAntenna, FlexSetSplit, FlexSetActiveSlice, FlexSetTXSlice,
   FlexSetNB, FlexSetNBLevel, FlexSetNR, FlexSetNRLevel, FlexSetANF, FlexSetANFLevel,
   FlexSetAPF, FlexSetAPFLevel, FlexSetCWSpeed, FlexSetCWPitch, FlexSetCWBreakInDelay,
   FlexSetCWSidetone, FlexSetSidetoneLevel, FlexSetCWFilter, FlexSetFilter,
@@ -30,8 +30,10 @@ type FlexState = {
   apf: boolean; apf_level: number; filter_lo: number; filter_hi: number;
   amp_available: boolean; amp_model?: string; amp_operate: boolean; amp_fault?: string;
   meters?: Meter[];
+  slices?: FlexSlice[];
 };
 
+type FlexSlice = { index: number; letter: string; freq_hz: number; mode?: string; band?: string; active: boolean; tx: boolean };
 type Meter = { id: number; src?: string; name?: string; unit?: string; value: number; lo: number; hi: number };
 
 const ZERO: FlexState = {
@@ -280,6 +282,37 @@ export function FlexPanel({ onCWSpeed, onReportRST }: { onCWSpeed?: (wpm: number
           </span>
         </div>
 
+        {/* Slices A/B/C/D — every in-use receiver. Click one to make it the
+            ACTIVE slice: the main frequency, mode, DSP and spot-clicks all follow
+            it. The active slice is highlighted; the TX slice is flagged. */}
+        {!!st.slices && st.slices.length > 0 && (
+          <div className="flex flex-wrap items-center gap-2">
+            {st.slices.map((sl) => (
+              <button key={sl.index} type="button" disabled={off}
+                onClick={() => FlexSetActiveSlice(sl.index).catch(() => {})}
+                title={t('flxp.sliceHint')}
+                className={cn('flex items-center gap-2 rounded-lg border px-3 py-1.5 transition-colors disabled:opacity-40',
+                  sl.active ? 'border-info bg-info/10 ring-1 ring-info' : 'border-border bg-card hover:bg-muted')}>
+                <span className={cn('inline-flex size-6 items-center justify-center rounded-md text-sm font-extrabold',
+                  sl.active ? 'bg-info text-info-foreground' : 'bg-muted text-muted-foreground')}>{sl.letter}</span>
+                <span className="font-mono font-bold tabular-nums text-sm">{(sl.freq_hz / 1e6).toFixed(3)}</span>
+                <span className="text-[11px] text-muted-foreground uppercase">{sl.mode}</span>
+                {sl.band ? <span className="text-[10px] text-muted-foreground">{sl.band}</span> : null}
+                {/* TX badge — click a non-TX slice's badge to move TX onto it
+                    (e.g. transmit on the active slice). stopPropagation so it
+                    doesn't also fire the outer "make active" click. */}
+                <span role="button" tabIndex={-1}
+                  onClick={(e) => { e.stopPropagation(); if (!sl.tx && !off) FlexSetTXSlice(sl.index).catch(() => {}); }}
+                  title={sl.tx ? t('flxp.txSlice') : t('flxp.setTxSlice')}
+                  className={cn('rounded text-[10px] font-bold px-1',
+                    sl.tx ? 'bg-danger text-danger-foreground' : 'border border-danger/50 text-danger cursor-pointer hover:bg-danger/10')}>
+                  TX
+                </span>
+              </button>
+            ))}
+          </div>
+        )}
+
         {off && (
           <div className="text-center text-sm text-muted-foreground py-6">
             {t('flxp.waiting')}

frontend/src/lib/i18n.tsx

@@ -191,7 +191,7 @@ const en: Dict = {
   'wkp.autoCallHint': 'Click a CQ macro (one whose text contains CQ) to resend it on a loop — message, gap, repeat — until you send another macro (e.g. a report), press Stop, or hit ESC. Non-CQ macros send once.', 'wkp.autoCall': 'Auto-call', 'wkp.gap': 'gap', 'wkp.gapHint': 'Seconds to wait after the message before resending', 'wkp.loopHint': 'click a CQ macro to loop it', 'wkp.macroN': 'Macro {n}',
   'dvkp.voiceKeyer': 'Voice keyer', 'dvkp.stop': 'Stop', 'dvkp.disable': 'Disable voice keyer', 'dvkp.noMsgPre': 'No messages recorded yet. Open', 'dvkp.settingsPath': 'Settings → Audio devices & voice keyer', 'dvkp.noMsgPost': 'to record F1–F6.', 'dvkp.transmit': 'Transmit F{slot}{label} ({dur}s)', 'dvkp.empty': 'F{slot} — empty', 'dvkp.message': 'message',
   'agp.portDeselect': 'Port {letter} — click to deselect', 'agp.portSelect': 'Select on port {letter}', 'agp.online': 'online', 'agp.offline': 'offline', 'agp.close': 'Close', 'agp.connecting': 'Connecting…', 'agp.noAntennas': 'No antennas configured.',
-  'flxp.smartsdrRemote': 'SmartSDR remote control', 'flxp.offline': 'OFFLINE', 'flxp.waiting': 'Waiting for the FlexRadio… (set CAT to FlexRadio and connect)', 'flxp.transmit': 'Transmit', 'flxp.rfPower': 'RF Power', 'flxp.tunePwr': 'Tune Pwr', 'flxp.splitHint': 'Split: RX/TX on separate slices. ON creates a TX slice +1 kHz (CW) / +5 kHz (SSB) up, like SmartSDR.', 'flxp.voxDly': 'VOX Dly', 'flxp.speed': 'Speed', 'flxp.pitch': 'Pitch', 'flxp.delay': 'Delay',
+  'flxp.smartsdrRemote': 'SmartSDR remote control', 'flxp.offline': 'OFFLINE', 'flxp.waiting': 'Waiting for the FlexRadio… (set CAT to FlexRadio and connect)', 'flxp.transmit': 'Transmit', 'flxp.rfPower': 'RF Power', 'flxp.tunePwr': 'Tune Pwr', 'flxp.splitHint': 'Split: RX/TX on separate slices. ON creates a TX slice +1 kHz (CW) / +5 kHz (SSB) up, like SmartSDR.', 'flxp.sliceHint': 'Click to make this the active slice — frequency, mode, DSP and spot-clicks all follow it.', 'flxp.txSlice': 'This slice transmits', 'flxp.setTxSlice': 'Move TX to this slice (transmit here)', 'flxp.voxDly': 'VOX Dly', 'flxp.speed': 'Speed', 'flxp.pitch': 'Pitch', 'flxp.delay': 'Delay',
   'flxp.receiveActive': 'Receive (active slice)', 'flxp.muted': 'Muted — click to unmute', 'flxp.mute': 'Mute RX audio', 'flxp.filter': 'Filter', 'flxp.amplifier': 'Amplifier', 'flxp.ampInLine': 'Amplifier is in line (transmitting through PA).', 'flxp.ampBypassed': 'Amplifier bypassed (standby).', 'flxp.pgConnected': 'PowerGenius connected', 'flxp.pgOffline': 'PowerGenius offline', 'flxp.fan': 'Fan', 'flxp.fanStandard': 'Standard', 'flxp.fanContest': 'Contest', 'flxp.fanBroadcast': 'Broadcast', 'flxp.fault': 'FAULT', 'flxp.meters': 'Meters', 'flxp.noMeters': "No meters yet — waiting for the radio's UDP stream…", 'flxp.amplifierHdr': 'AMPLIFIER',
   'icmp.spectrum': 'Spectrum', 'icmp.scopeFixed': 'Fixed — double-click / wheel to tune', 'icmp.scopeCenter': 'Center — follows VFO', 'icmp.scopeOff': 'Scope off', 'icmp.scopePanDown': 'Shift scope −50 kHz', 'icmp.scopePanUp': 'Shift scope +50 kHz', 'icmp.scopeCenterVfo': 'Center scope on the current frequency (±50 kHz)', 'icmp.notConnected': "Icom not connected. Enable the Icom CI-V backend in Settings → CAT and connect the radio's USB port.", 'icmp.refresh': 'Refresh', 'icmp.meters': 'Meters', 'icmp.transmit': 'Transmit', 'icmp.power': 'Power', 'icmp.mic': 'Mic', 'icmp.receive': 'Receive', 'icmp.preamp': 'Preamp', 'icmp.filter': 'Filter', 'icmp.noiseNotch': 'Noise / Notch', 'icmp.autoNotch': 'Auto notch filter', 'icmp.apf': 'Audio peak filter (CW)', 'icmp.clarifiers': 'RIT / ΔTX', 'icmp.ritHint': 'Wheel or ± to shift · Ctrl+←/→ shifts RIT when active', 'icmp.bandsAntenna': 'Bands & Antenna', 'icmp.antenna': 'Antenna', 'icmp.passband': 'Passband / Notch', 'icmp.pbtCenter': 'Center PBT', 'icmp.manualNotch': 'Manual notch — MN on, then set position', 'icmp.squelch': 'Squelch', 'icmp.powerOnHint': 'Power the radio ON (boots ~15 s)', 'icmp.powerOffHint': 'Power the radio OFF', 'icmp.powerOffConfirm': 'Switch the radio OFF?',
   'rst.clickToFill': 'Click to set RST tx from the signal',
@@ -377,7 +377,7 @@ const fr: Dict = {
   'wkp.autoCallHint': "Clique une macro CQ (dont le texte contient CQ) pour la réémettre en boucle — message, pause, répétition — jusqu'à envoyer une autre macro (ex. un report), appuyer sur Stop ou ESC. Les macros non-CQ ne sont émises qu'une fois.", 'wkp.autoCall': 'Appel auto', 'wkp.gap': 'pause', 'wkp.gapHint': 'Secondes à attendre après le message avant de réémettre', 'wkp.loopHint': 'clique une macro CQ pour la boucler', 'wkp.macroN': 'Macro {n}',
   'dvkp.voiceKeyer': 'Manipulateur vocal', 'dvkp.stop': 'Stop', 'dvkp.disable': 'Désactiver le manipulateur vocal', 'dvkp.noMsgPre': 'Aucun message enregistré. Ouvre', 'dvkp.settingsPath': 'Réglages → Périphériques audio & manipulateur vocal', 'dvkp.noMsgPost': 'pour enregistrer F1–F6.', 'dvkp.transmit': 'Émettre F{slot}{label} ({dur}s)', 'dvkp.empty': 'F{slot} — vide', 'dvkp.message': 'message',
   'agp.portDeselect': 'Port {letter} — clic pour désélectionner', 'agp.portSelect': 'Sélectionner sur le port {letter}', 'agp.online': 'en ligne', 'agp.offline': 'hors ligne', 'agp.close': 'Fermer', 'agp.connecting': 'Connexion…', 'agp.noAntennas': 'Aucune antenne configurée.',
-  'flxp.smartsdrRemote': 'Contrôle à distance SmartSDR', 'flxp.offline': 'HORS LIGNE', 'flxp.waiting': 'En attente du FlexRadio… (règle le CAT sur FlexRadio et connecte)', 'flxp.transmit': 'Émission', 'flxp.rfPower': 'Puissance RF', 'flxp.tunePwr': 'Puiss. TUNE', 'flxp.splitHint': 'Split : RX/TX sur des slices séparées. ON crée une slice TX +1 kHz (CW) / +5 kHz (SSB) au-dessus, comme SmartSDR.', 'flxp.voxDly': 'Délai VOX', 'flxp.speed': 'Vitesse', 'flxp.pitch': 'Tonalité', 'flxp.delay': 'Délai',
+  'flxp.smartsdrRemote': 'Contrôle à distance SmartSDR', 'flxp.offline': 'HORS LIGNE', 'flxp.waiting': 'En attente du FlexRadio… (règle le CAT sur FlexRadio et connecte)', 'flxp.transmit': 'Émission', 'flxp.rfPower': 'Puissance RF', 'flxp.tunePwr': 'Puiss. TUNE', 'flxp.splitHint': 'Split : RX/TX sur des slices séparées. ON crée une slice TX +1 kHz (CW) / +5 kHz (SSB) au-dessus, comme SmartSDR.', 'flxp.sliceHint': 'Cliquer pour rendre cette slice active — fréquence, mode, DSP et clics de spot la suivent tous.', 'flxp.txSlice': 'Cette slice émet', 'flxp.setTxSlice': 'Déplacer le TX sur cette slice (émettre ici)', 'flxp.voxDly': 'Délai VOX', 'flxp.speed': 'Vitesse', 'flxp.pitch': 'Tonalité', 'flxp.delay': 'Délai',
   'flxp.receiveActive': 'Réception (slice active)', 'flxp.muted': 'Coupé — clic pour rétablir', 'flxp.mute': "Couper l'audio RX", 'flxp.filter': 'Filtre', 'flxp.amplifier': 'Amplificateur', 'flxp.ampInLine': 'Amplificateur en ligne (émission via le PA).', 'flxp.ampBypassed': 'Amplificateur en bypass (standby).', 'flxp.pgConnected': 'PowerGenius connecté', 'flxp.pgOffline': 'PowerGenius hors ligne', 'flxp.fan': 'Ventilo', 'flxp.fanStandard': 'Standard', 'flxp.fanContest': 'Contest', 'flxp.fanBroadcast': 'Diffusion', 'flxp.fault': 'DÉFAUT', 'flxp.meters': 'Mesures', 'flxp.noMeters': 'Aucune mesure — en attente du flux UDP de la radio…', 'flxp.amplifierHdr': 'AMPLIFICATEUR',
   'icmp.spectrum': 'Spectre', 'icmp.scopeFixed': 'Fixe — double-clic / molette pour accorder', 'icmp.scopeCenter': 'Centré — suit le VFO', 'icmp.scopeOff': 'Scope éteint', 'icmp.scopePanDown': 'Décaler le scope −50 kHz', 'icmp.scopePanUp': 'Décaler le scope +50 kHz', 'icmp.scopeCenterVfo': 'Centrer le scope sur la fréquence actuelle (±50 kHz)', 'icmp.notConnected': 'Icom non connecté. Active le backend CI-V Icom dans Réglages → CAT et connecte le port USB de la radio.', 'icmp.refresh': 'Rafraîchir', 'icmp.meters': 'Mesures', 'icmp.transmit': 'Émission', 'icmp.power': 'Puissance', 'icmp.mic': 'Micro', 'icmp.receive': 'Réception', 'icmp.preamp': 'Préampli', 'icmp.filter': 'Filtre', 'icmp.noiseNotch': 'Bruit / Notch', 'icmp.autoNotch': 'Filtre notch auto', 'icmp.apf': 'Filtre de pic audio (CW)', 'icmp.clarifiers': 'RIT / ΔTX', 'icmp.ritHint': 'Molette ou ± pour décaler · Ctrl+←/→ décale le RIT si actif', 'icmp.bandsAntenna': 'Bandes & Antenne', 'icmp.antenna': 'Antenne', 'icmp.passband': 'Passe-bande / Notch', 'icmp.pbtCenter': 'Centrer PBT', 'icmp.manualNotch': 'Notch manuel — active MN, puis règle la position', 'icmp.squelch': 'Squelch', 'icmp.powerOnHint': 'Allumer la radio (démarre en ~15 s)', 'icmp.powerOffHint': 'Éteindre la radio', 'icmp.powerOffConfirm': 'Éteindre la radio ?',
   'rst.clickToFill': 'Clic pour remplir le RST tx depuis le signal',

frontend/wailsjs/go/main/App.d.ts

@@ -172,6 +172,8 @@ export function FlexSetAPFLevel(arg1:number):Promise<void>;
 
 export function FlexSetATUMemories(arg1:boolean):Promise<void>;
 
+export function FlexSetActiveSlice(arg1:number):Promise<void>;
+
 export function FlexSetAudioLevel(arg1:number):Promise<void>;
 
 export function FlexSetCWBreakInDelay(arg1:number):Promise<void>;
@@ -216,6 +218,8 @@ export function FlexSetSplit(arg1:boolean):Promise<void>;
 
 export function FlexSetTXAntenna(arg1:string):Promise<void>;
 
+export function FlexSetTXSlice(arg1:number):Promise<void>;
+
 export function FlexSetTunePower(arg1:number):Promise<void>;
 
 export function FlexSetVox(arg1:boolean):Promise<void>;

frontend/wailsjs/go/main/App.js

@@ -306,6 +306,10 @@ export function FlexSetATUMemories(arg1) {
   return window['go']['main']['App']['FlexSetATUMemories'](arg1);
 }
 
+export function FlexSetActiveSlice(arg1) {
+  return window['go']['main']['App']['FlexSetActiveSlice'](arg1);
+}
+
 export function FlexSetAudioLevel(arg1) {
   return window['go']['main']['App']['FlexSetAudioLevel'](arg1);
 }
@@ -394,6 +398,10 @@ export function FlexSetTXAntenna(arg1) {
   return window['go']['main']['App']['FlexSetTXAntenna'](arg1);
 }
 
+export function FlexSetTXSlice(arg1) {
+  return window['go']['main']['App']['FlexSetTXSlice'](arg1);
+}
+
 export function FlexSetTunePower(arg1) {
   return window['go']['main']['App']['FlexSetTunePower'](arg1);
 }

frontend/wailsjs/go/models.ts

@@ -541,9 +541,34 @@ export namespace cat {
 	        this.callsign = source["callsign"];
 	    }
 	}
+	export class FlexSliceInfo {
+	    index: number;
+	    letter: string;
+	    freq_hz: number;
+	    mode?: string;
+	    band?: string;
+	    active: boolean;
+	    tx: boolean;
+	
+	    static createFrom(source: any = {}) {
+	        return new FlexSliceInfo(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.index = source["index"];
+	        this.letter = source["letter"];
+	        this.freq_hz = source["freq_hz"];
+	        this.mode = source["mode"];
+	        this.band = source["band"];
+	        this.active = source["active"];
+	        this.tx = source["tx"];
+	    }
+	}
 	export class FlexTXState {
 	    available: boolean;
 	    model?: string;
+	    slices?: FlexSliceInfo[];
 	    rf_power: number;
 	    tune_power: number;
 	    tune: boolean;
@@ -600,6 +625,7 @@ export namespace cat {
 	        if ('string' === typeof source) source = JSON.parse(source);
 	        this.available = source["available"];
 	        this.model = source["model"];
+	        this.slices = this.convertValues(source["slices"], FlexSliceInfo);
 	        this.rf_power = source["rf_power"];
 	        this.tune_power = source["tune_power"];
 	        this.tune = source["tune"];

internal/cat/cat.go

@@ -245,9 +245,24 @@ func (m *Manager) SendSpot(s SpotInfo) {
 // FlexTXState is the FlexRadio transmit/ATU state surfaced to the dedicated
 // FlexRadio control tab. Levels are 0-100. (Phase 1: controls + state pushed by
 // the radio over TCP; live meters arrive over a separate UDP stream later.)
+// FlexSliceInfo identifies one FlexRadio receiver slice (A/B/C/D…) for the
+// panel, so the operator sees every slice and which one is active/TX.
+type FlexSliceInfo struct {
+	Index  int    `json:"index"`  // 0-based slice index
+	Letter string `json:"letter"` // A, B, C, D…
+	FreqHz int64  `json:"freq_hz"`
+	Mode   string `json:"mode,omitempty"` // ADIF mode
+	Band   string `json:"band,omitempty"`
+	Active bool   `json:"active"` // the focused/operating slice
+	TX     bool   `json:"tx"`     // this slice transmits
+}
+
 type FlexTXState struct {
 	Available    bool   `json:"available"` // backend is Flex and handshaked
 	Model        string `json:"model,omitempty"`
+	// Slices lists every in-use receiver slice (A/B/C/D…) so the panel can show
+	// them all and highlight the active one. The active slice drives everything.
+	Slices []FlexSliceInfo `json:"slices,omitempty"`
 	RFPower      int    `json:"rf_power"`
 	TunePower    int    `json:"tune_power"`
 	Tune         bool   `json:"tune"`         // tune carrier active
@@ -339,6 +354,8 @@ type FlexController interface {
 	SetMute(bool) error
 	SetRXAntenna(string) error
 	SetTXAntenna(string) error
+	SetActiveSlice(int) error // focus slice idx so commands target it
+	SetTXSlice(int) error     // make slice idx the transmitter (tx=1)
 	SetSplit(bool) error
 	SetNB(bool) error
 	SetNBLevel(int) error

internal/cat/flex.go

@@ -774,21 +774,19 @@ func (f *Flex) ReadState() (RigState, error) {
 	if !f.gotHandle {
 		return st, nil // connected TCP but radio hasn't handshaked yet
 	}
-	rx, tx := f.pickSlicesLocked()
+	main, rxS, txSplit := f.operatingLocked()
-	if rx == nil && tx == nil {
+	if main == nil {
 		return st, nil
 	}
-	if tx == nil {
+	// Main frequency/mode = the ACTIVE slice (what the operator is on). Only a
-		tx = rx
+	// genuine same-band split adds a separate TX freq; then ADIF convention wants
-	}
+	// FreqHz = TX and RxFreqHz = RX.
-	if rx == nil {
+	st.FreqHz = main.freqHz
-		rx = tx
+	st.Mode = flexModeToADIF(main.mode)
-	}
+	if rxS != nil && txSplit != nil {
-	st.FreqHz = tx.freqHz
-	st.Mode = flexModeToADIF(tx.mode)
-	if rx.freqHz != tx.freqHz {
 		st.Split = true
-		st.RxFreqHz = rx.freqHz
+		st.RxFreqHz = rxS.freqHz
+		st.FreqHz = txSplit.freqHz
 	}
 	sig := fmt.Sprintf("%d/%d/%v/%s", st.FreqHz, st.RxFreqHz, st.Split, st.Mode)
 	if sig != f.lastStateSig {
@@ -798,76 +796,130 @@ func (f *Flex) ReadState() (RigState, error) {
 	return st, nil
 }
 
-// pickSlicesLocked chooses the TX and RX slices among in-use slices. TX is the
+// mainSliceLocked is the operator's slice: the ACTIVE (focused) in-use slice, or
-// slice flagged tx=1. RX is the slice you actually receive on — the NON-TX slice
+// the lowest-indexed in-use slice when none is flagged active. EVERYTHING the
-// (preferring the active/focused one), NOT simply the active slice: tuning the
+// user does — freq/mode display, RX DSP, tuning, mode changes, spot clicks —
-// TX slice makes it the active/focused slice, which would otherwise collapse RX
+// follows this slice, so a second independent slice (e.g. monitoring another
-// onto TX and hide the split. Caller holds f.mu.
+// band) never hijacks the main frequency. Returns (-1, nil) when no slice is in
-func (f *Flex) pickSlicesLocked() (rx, tx *flexSlice) {
+// use. Caller holds f.mu.
-	idxs := make([]int, 0, len(f.slices))
+func (f *Flex) mainSliceLocked() (int, *flexSlice) {
-	for i, s := range f.slices {
+	best, bestS := 1<<30, (*flexSlice)(nil)
-		if s.inUse {
-			idxs = append(idxs, i)
-		}
-	}
-	sort.Ints(idxs)
-	var active, txS, nonTx, first *flexSlice
-	for _, i := range idxs {
-		s := f.slices[i]
-		if first == nil {
-			first = s
-		}
-		if s.active {
-			active = s
-		}
-		if s.tx {
-			txS = s
-		} else if nonTx == nil {
-			nonTx = s
-		}
-	}
-	tx = txS
-	if tx == nil {
-		if active != nil {
-			tx = active
-		} else {
-			tx = first
-		}
-	}
-	// RX = the receive slice: the active one if it isn't the TX slice, else the
-	// first non-TX slice; fall back to TX (simplex) when there's only one slice.
-	switch {
-	case active != nil && active != tx:
-		rx = active
-	case nonTx != nil:
-		rx = nonTx
-	default:
-		rx = tx
-	}
-	return rx, tx
-}
-
-// activeSliceIndexLocked returns the slice index to send commands to (the active
-// slice, else the lowest in-use index, else 0). Caller holds f.mu.
-func (f *Flex) activeSliceIndexLocked() int {
-	best, found := 1<<30, false
 	for idx, s := range f.slices {
 		if !s.inUse {
 			continue
 		}
 		if s.active {
-			return idx
+			return idx, s
 		}
 		if idx < best {
-			best, found = idx, true
+			best, bestS = idx, s
 		}
 	}
-	if found {
+	if bestS != nil {
-		return best
+		return best, bestS
+	}
+	return -1, nil
+}
+
+// activeSliceIndexLocked returns the slice index to send commands to (the main
+// slice, else 0). Caller holds f.mu.
+func (f *Flex) activeSliceIndexLocked() int {
+	if idx, _ := f.mainSliceLocked(); idx >= 0 {
+		return idx
 	}
 	return 0
 }
 
+// sliceLetter maps a slice index to its SmartSDR letter (0→A, 1→B, …).
+func sliceLetter(idx int) string {
+	if idx < 0 || idx > 25 {
+		return fmt.Sprintf("%d", idx)
+	}
+	return string(rune('A' + idx))
+}
+
+// txSliceLocked returns the slice flagged as the transmitter (tx=1), or nil.
+// Caller holds f.mu.
+func (f *Flex) txSliceLocked() *flexSlice {
+	for _, s := range f.slices {
+		if s.inUse && s.tx {
+			return s
+		}
+	}
+	return nil
+}
+
+// operatingLocked resolves the operator's slices: the MAIN (active) slice for the
+// mode/display, and — ONLY for a GENUINE split — the RX and TX slices. Split is
+// the tx-flagged slice PLUS a distinct in-use slice on the SAME band (different
+// freq) — detected from the pair itself, NOT from which slice is active (the TX
+// slice often steals focus right after "slice create", which must NOT read as
+// "no split"). A slice on another band is an independent receiver, ignored.
+// Caller holds f.mu.
+func (f *Flex) operatingLocked() (main, rx, tx *flexSlice) {
+	_, main = f.mainSliceLocked()
+	txS := f.txSliceLocked()
+	if txS == nil {
+		return main, nil, nil
+	}
+	bt := BandFromHz(txS.freqHz)
+	if bt == "" {
+		return main, nil, nil
+	}
+	// RX = the active slice when it's a distinct same-band slice, else the first
+	// other in-use same-band slice.
+	if main != nil && main != txS && main.freqHz != txS.freqHz && BandFromHz(main.freqHz) == bt {
+		rx = main
+	} else {
+		for _, s := range f.slices {
+			if s.inUse && s != txS && s.freqHz != txS.freqHz && BandFromHz(s.freqHz) == bt {
+				rx = s
+				break
+			}
+		}
+	}
+	if rx == nil {
+		return main, nil, nil // tx slice alone (simplex) → not split
+	}
+	return main, rx, txS
+}
+
+// SetActiveSlice focuses slice idx on the radio so every subsequent command
+// (freq / mode / DSP / spot click) targets it. Lets the operator pick the
+// operating slice from OpsLog (like SliceLogger's A/B selector).
+func (f *Flex) SetActiveSlice(idx int) error {
+	f.mu.Lock()
+	_, exists := f.slices[idx]
+	connected := f.conn != nil
+	f.mu.Unlock()
+	if !connected {
+		return fmt.Errorf("flex: not connected")
+	}
+	if !exists {
+		return fmt.Errorf("flex: no slice %d", idx)
+	}
+	f.send(fmt.Sprintf("slice s %d active=1", idx))
+	return nil
+}
+
+// SetTXSlice makes slice idx the transmitter (tx=1) — e.g. "put TX on the active
+// slice" so you transmit where you're listening. Only one slice can be TX; the
+// radio clears the flag on the others.
+func (f *Flex) SetTXSlice(idx int) error {
+	f.mu.Lock()
+	_, exists := f.slices[idx]
+	connected := f.conn != nil
+	f.mu.Unlock()
+	if !connected {
+		return fmt.Errorf("flex: not connected")
+	}
+	if !exists {
+		return fmt.Errorf("flex: no slice %d", idx)
+	}
+	f.send(fmt.Sprintf("slice s %d tx=1", idx))
+	return nil
+}
+
 func (f *Flex) SetFrequency(hz int64) error {
 	if hz <= 0 {
 		return fmt.Errorf("flex: invalid frequency")
@@ -1048,19 +1100,10 @@ func clampLevel(v int) int {
 	return v
 }
 
-// rxSliceLocked returns the active RX slice and its index (-1 when none), using
+// rxSliceLocked returns the operator's (main/active) slice and its index — the
-// the same RX-selection rule as ReadState. Caller holds f.mu.
+// slice every RX-DSP control and read targets. Caller holds f.mu.
 func (f *Flex) rxSliceLocked() (int, *flexSlice) {
-	rx, _ := f.pickSlicesLocked()
+	return f.mainSliceLocked()
-	if rx == nil {
-		return -1, nil
-	}
-	for i, s := range f.slices {
-		if s == rx {
-			return i, rx
-		}
-	}
-	return -1, rx
 }
 
 // FlexState returns a snapshot of the radio's transmit/ATU state plus the active
@@ -1093,10 +1136,31 @@ func (f *Flex) FlexState() FlexTXState {
 		CWSidetone:     f.tx.cwSidetone,
 		CWMonLevel:     f.tx.cwMonLevel,
 	}
-	if rx, tx := f.pickSlicesLocked(); rx != nil && tx != nil && rx != tx && rx.freqHz != tx.freqHz {
+	if _, rxS, txSplit := f.operatingLocked(); rxS != nil && txSplit != nil {
 		st.Split = true
-		st.RXFreqHz = rx.freqHz
+		st.RXFreqHz = rxS.freqHz
-		st.TXFreqHz = tx.freqHz
+		st.TXFreqHz = txSplit.freqHz
+	}
+	// Every in-use slice (A/B/C/D…) so the panel shows them all and highlights the
+	// active/TX one — the active slice drives everything the operator does.
+	sidx := make([]int, 0, len(f.slices))
+	for i, s := range f.slices {
+		if s.inUse {
+			sidx = append(sidx, i)
+		}
+	}
+	sort.Ints(sidx)
+	for _, i := range sidx {
+		s := f.slices[i]
+		st.Slices = append(st.Slices, FlexSliceInfo{
+			Index:  i,
+			Letter: sliceLetter(i),
+			FreqHz: s.freqHz,
+			Mode:   flexModeToADIF(s.mode),
+			Band:   BandFromHz(s.freqHz),
+			Active: s.active,
+			TX:     s.tx,
+		})
 	}
 	if _, rx := f.rxSliceLocked(); rx != nil {
 		st.RXAvail = true
@@ -1229,35 +1293,40 @@ func (f *Flex) SetSplit(on bool) error {
 		f.mu.Unlock()
 		return fmt.Errorf("flex: not connected")
 	}
-	rx, tx := f.pickSlicesLocked()
+	// Split is built AROUND THE ACTIVE slice, and "already split" uses the SAME
+	// same-band-pair rule as the button state (operatingLocked) — otherwise two
+	// INDEPENDENT slices on different bands look "already split" and SPLIT ON does
+	// nothing (the bug the user hit: A on 20m + B on 80m).
+	main, rxS, txS := f.operatingLocked()
 	rxIdx, txIdx := -1, -1
 	for i, s := range f.slices {
-		if s == rx {
+		if s == rxS {
 			rxIdx = i
 		}
-		if s == tx {
+		if s == txS {
 			txIdx = i
 		}
 	}
-	alreadySplit := rx != nil && tx != nil && rx != tx
+	alreadySplit := rxS != nil && txS != nil
-	var rxFreq int64
+	var baseFreq int64
-	var rxMode, rxAnt string
+	var baseMode, baseAnt string
-	if rx != nil {
+	if main != nil {
-		rxFreq, rxMode, rxAnt = rx.freqHz, rx.mode, rx.rxAnt
+		baseFreq, baseMode, baseAnt = main.freqHz, main.mode, main.rxAnt
 	}
 	f.mu.Unlock()
 
 	if on {
-		if alreadySplit || rx == nil {
+		if alreadySplit || main == nil {
-			return nil // already split (or no slice)
+			return nil // already split, or no active slice
 		}
 		offset := int64(5000)
-		if strings.HasPrefix(strings.ToUpper(rxMode), "CW") {
+		if strings.HasPrefix(strings.ToUpper(baseMode), "CW") {
 			offset = 1000
 		}
-		cmd := fmt.Sprintf("slice create freq=%.6f mode=%s", float64(rxFreq+offset)/1e6, rxMode)
+		// Create the TX slice at the ACTIVE slice's freq + offset (same band).
-		if rxAnt != "" {
+		cmd := fmt.Sprintf("slice create freq=%.6f mode=%s", float64(baseFreq+offset)/1e6, baseMode)
-			cmd += " ant=" + rxAnt
+		if baseAnt != "" {
+			cmd += " ant=" + baseAnt
 		}
 		if seq := f.send(cmd); seq > 0 {
 			f.mu.Lock()
@@ -1270,10 +1339,10 @@ func (f *Flex) SetSplit(on bool) error {
 		return nil
 	}
 	if txIdx >= 0 {
-		f.send(fmt.Sprintf("slice remove %d", txIdx))
+		f.send(fmt.Sprintf("slice remove %d", txIdx)) // drop the extra TX slice
 	}
 	if rxIdx >= 0 {
-		f.send(fmt.Sprintf("slice s %d tx=1", rxIdx))
+		f.send(fmt.Sprintf("slice s %d tx=1", rxIdx)) // RX slice transmits again
 	}
 	return nil
 }