diff --git a/routes/morse.py b/routes/morse.py
index 0807247..6d4d639 100644
--- a/routes/morse.py
+++ b/routes/morse.py
@@ -265,12 +265,10 @@ def start_morse() -> Response:
 
         _set_state(MORSE_STARTING, 'Starting decoder...')
 
-    sample_rate = 8000
+    # Use pager-proven audio rate for rtl_fm compatibility across builds.
+    sample_rate = 22050
     bias_t = _bool_value(data.get('bias_t', False), False)
 
-    # RTL-SDR needs direct sampling mode for HF frequencies below 24 MHz
-    direct_sampling = 2 if freq < 24.0 else None
-
     sdr_type_str = data.get('sdr_type', 'rtlsdr')
     try:
         sdr_type = SDRType(sdr_type_str)
@@ -280,15 +278,22 @@ def start_morse() -> Response:
     sdr_device = SDRFactory.create_default_device(sdr_type, index=device)
     builder = SDRFactory.get_builder(sdr_device.sdr_type)
 
+    fm_kwargs: dict[str, Any] = {
+        'device': sdr_device,
+        'frequency_mhz': freq,
+        'sample_rate': sample_rate,
+        'gain': float(gain) if gain and gain != '0' else None,
+        'ppm': int(ppm) if ppm and ppm != '0' else None,
+        'modulation': 'usb',
+        'bias_t': bias_t,
+    }
+
+    # Only rtl_fm supports direct sampling flags.
+    if sdr_device.sdr_type == SDRType.RTL_SDR and freq < 24.0:
+        fm_kwargs['direct_sampling'] = 2
+
     rtl_cmd = builder.build_fm_demod_command(
-        device=sdr_device,
-        frequency_mhz=freq,
-        sample_rate=sample_rate,
-        gain=float(gain) if gain and gain != '0' else None,
-        ppm=int(ppm) if ppm and ppm != '0' else None,
-        modulation='usb',
-        bias_t=bias_t,
-        direct_sampling=direct_sampling,
+        **fm_kwargs,
     )
 
     full_cmd = ' '.join(rtl_cmd)
diff --git a/static/js/modes/morse.js b/static/js/modes/morse.js
index f0d6f31..8c60ffc 100644
--- a/static/js/modes/morse.js
+++ b/static/js/modes/morse.js
@@ -173,11 +173,18 @@ var MorseMode = (function () {
     function loadSettings() {
         try {
             var raw = localStorage.getItem(SETTINGS_KEY);
-            if (!raw) return;
+            if (!raw) {
+                if (el('morseShowDiag')) el('morseShowDiag').checked = true;
+                toggleDiagPanel();
+                persistSettings();
+                return;
+            }
             var parsed = JSON.parse(raw);
             applySettings(parsed);
         } catch (_) {
             // Ignore malformed settings.
+            if (el('morseShowDiag')) el('morseShowDiag').checked = true;
+            toggleDiagPanel();
         }
     }
 
@@ -555,6 +562,11 @@ var MorseMode = (function () {
             if (!scopeWaiting) {
                 scopeWaiting = true;
                 waitingStart = Date.now();
+                appendDiagLine('[morse] waiting for PCM stream...');
+            }
+            var waitElapsedMs = waitingStart ? (Date.now() - waitingStart) : 0;
+            if (waitElapsedMs > 10000 && el('morseDiagLog') && el('morseDiagLog').children.length < 6) {
+                appendDiagLine('[hint] No samples after 10s. Check SDR device, frequency, and HF direct sampling path.');
             }
         } else if (amps.length > 0) {
             scopeWaiting = false;
@@ -812,6 +824,9 @@ var MorseMode = (function () {
         if (!log) return;
 
         var showDiag = !!(el('morseShowDiag') && el('morseShowDiag').checked);
+        if (!showDiag && scopeWaiting) {
+            showDiag = true;
+        }
         if (!showDiag) return;
 
         log.style.display = 'block';