diff --git a/htdocs/lib/BookmarkBar.js b/htdocs/lib/BookmarkBar.js
index 9104639d..cffeb295 100644
--- a/htdocs/lib/BookmarkBar.js
+++ b/htdocs/lib/BookmarkBar.js
@@ -8,12 +8,10 @@ function BookmarkBar() {
     me.$container.on('click', '.bookmark', function(e){
         var $bookmark = $(e.target).closest('.bookmark');
         me.$container.find('.bookmark').removeClass('selected');
-        var b = $bookmark.data();
-        if (!b || !b.frequency || !b.modulation) return;
-        UI.setFrequency(b.frequency);
-        UI.setModulation(b.modulation, b.underlying);
-        $bookmark.addClass('selected');
-        stopScanner();
+        if (UI.tuneBookmark($bookmark.data())) {
+            $bookmark.addClass('selected');
+            UI.toggleScanner(false);
+        }
     });
 
     me.$container.on('click', '.action[data-action=edit]', function(e){
diff --git a/htdocs/lib/Scanner.js b/htdocs/lib/Scanner.js
index 309f3803..43e75926 100644
--- a/htdocs/lib/Scanner.js
+++ b/htdocs/lib/Scanner.js
@@ -5,17 +5,7 @@ function Scanner(bookmarkBar, msec) {
     this.msec      = msec;
     this.current   = -1;
     this.threshold = -80;
-}
-
-Scanner.prototype.tuneBookmark = function(b) {
-    //console.log("TUNE: " + b.name + " at " + b.frequency + ": " + b.modulation);
-
-    // Tune to the bookmark frequency
-    UI.setFrequency(b.frequency);
-    UI.setModulation(b.modulation, b.underlying);
-
-    // Done
-    return true;
+    this.timer     = 0;
 }
 
 Scanner.prototype.update = function(data) {
@@ -61,7 +51,7 @@ Scanner.prototype.scan = function() {
         //console.log("SCAN: " + b.name + " at " + b.frequency + ": " + b.level);
 
         // If level exceeds threshold, tune to the bookmark
-        if (b.level>this.threshold && this.tuneBookmark(b)) {
+        if (b.level>this.threshold && UI.tuneBookmark(b)) {
             this.current = current;
             return;
         }
@@ -82,7 +72,7 @@ Scanner.prototype.stop = function() {
     }
 
     // Done
-    return this.timer == null;
+    return !this.timer;
 }
 
 Scanner.prototype.start = function() {
@@ -111,15 +101,10 @@ Scanner.prototype.start = function() {
     }
 
     // Done
-    return this.timer != null;
+    return !!this.timer;
 }
 
-Scanner.prototype.toggle = function() {
-    // Toggle based on the current timer state
-    return this.timer? this.stop() : this.start();
-};
-
 Scanner.prototype.isRunning = function() {
     // Return current state
-    return this.timer != null;
+    return !!this.timer;
 };
diff --git a/htdocs/lib/Shortcuts.js b/htdocs/lib/Shortcuts.js
index b9e7c3e0..2a4449d8 100644
--- a/htdocs/lib/Shortcuts.js
+++ b/htdocs/lib/Shortcuts.js
@@ -289,7 +289,7 @@ Shortcuts.handleKey = function(event) {
 
         case 's':
             // S: Toggle scanner
-            toggleScanner();
+            UI.toggleScanner();
             break;
 
         case 'd':
diff --git a/htdocs/lib/UI.js b/htdocs/lib/UI.js
index 2981f100..19caa0a3 100644
--- a/htdocs/lib/UI.js
+++ b/htdocs/lib/UI.js
@@ -130,6 +130,21 @@ UI.setFrequency = function(freq) {
     return this.setOffsetFrequency(freq - center_freq);
 };
 
+UI.tuneBookmark = function(b) {
+    // Bookmark must have frequency and modulation
+    if (!b || !b.frequency || !b.modulation) return false;
+
+    //console.log("TUNE: " + b.name + " at " + b.frequency + ": " + b.modulation);
+
+    // Tune to the bookmark frequency
+    var freq = b.modulation === 'cw'? b.frequency - 800 : b.frequency;
+    UI.setFrequency(freq, b.modulation);
+    UI.setModulation(b.modulation, b.underlying);
+
+    // Done
+    return true;
+};
+
 //
 // Volume Controls
 //
@@ -230,6 +245,33 @@ UI.toggleRecording = function(on) {
     }
 };
 
+//
+// Scanner Controls
+//
+
+UI.toggleScanner = function(on) {
+    // If no argument given, toggle scanner
+    if (typeof(on) === 'undefined') on = !scanner.isRunning();
+
+    // Do not change scanner state if not needed
+    if (scanner.isRunning() == on) return;
+
+    // Start or stop scanner as needed
+    if (on) scanner.start(); else scanner.stop();
+
+    // Get current scanner state
+    on = scanner.isRunning();
+
+    // Update UI elements
+    var $scanButton = $('.openwebrx-squelch-auto');
+    $scanButton.css('animation-name', on? 'openwebrx-scan-animation' : '');
+    if (on) {
+        $scanButton.addClass('highlighted');
+    } else {
+        $scanButton.removeClass('highlighted');
+    }
+};
+
 //
 // Look & Feel Controls
 //
diff --git a/htdocs/lib/Utils.js b/htdocs/lib/Utils.js
index 7b40605b..d3455cee 100644
--- a/htdocs/lib/Utils.js
+++ b/htdocs/lib/Utils.js
@@ -70,10 +70,11 @@ Utils.offsetFreq = function(freq, mod) {
         case 'rtty450':
         case 'rtty170':
         case 'rtty85':
-        case 'sitorb':
-        case 'dsc':
         case 'bpsk31':
         case 'bpsk63':
+        case 'sitorb':
+        case 'navtex':
+        case 'dsc':
             return freq - 1000;
     }
 
diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index 2bf3cccb..08112933 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -290,7 +290,7 @@ function scale_canvas_end_drag(x) {
     for (var i = 0; i < demodulators.length; i++) event_handled |= demodulators[i].envelope.drag_end();
     if (!event_handled) {
         demodulators[0].set_offset_frequency(scale_offset_freq_from_px(x));
-        stopScanner();
+        UI.toggleScanner(false);
     }
 }
 
@@ -733,7 +733,7 @@ function canvas_mouseup(evt) {
             // For CW, move offset 800Hz below the actual carrier
             if (UI.getModulation() === 'cw') f = f - 800;
             UI.setOffsetFrequency(f);
-            stopScanner();
+            UI.toggleScanner(false);
         } else {
             canvas_end_drag();
         }
@@ -929,7 +929,7 @@ function on_ws_recv(evt) {
                             currentprofile['profile_id'] = config['profile_id'] || currentprofile['profile_id'];
                             $('#openwebrx-sdr-profiles-listbox').val(currentprofile.toString());
 
-                            stopScanner();
+                            UI.toggleScanner(false);
                             tuning_step_reset();
                             waterfall_clear();
                             zoom_set(0);
@@ -1449,7 +1449,7 @@ function initSliders() {
 
     // Enable scanner by pressing the right mouse button on SQUELCH
     $('.openwebrx-squelch-auto').on('contextmenu', function() {
-        toggleScanner();
+        UI.toggleScanner();
         return false;
     });
 }
@@ -1578,29 +1578,6 @@ function initSpectrum() {
     spectrum = new Spectrum(canvas, 150);
 }
 
-function stopScanner() {
-    if (scanner.isRunning()) {
-        // Stop scanner
-        scanner.stop();
-        // Modify scanner button state
-        var $scanButton = $('.openwebrx-squelch-auto');
-        $scanButton.css('animation-name', '');
-        $scanButton.removeClass('highlighted');
-    }
-}
-
-function toggleScanner() {
-    var $scanButton = $('.openwebrx-squelch-auto');
-    var on = scanner.toggle();
-
-    $scanButton.css('animation-name', on? 'openwebrx-scan-animation' : '');
-    if (on) {
-        $scanButton.addClass('highlighted');
-    } else {
-        $scanButton.removeClass('highlighted');
-    }
-}
-
 /*
   _____  _       _                     _
  |  __ \(_)     (_)                   | |