diff --git a/src/Nonemm.App/AppSession.QsySpot.cs b/src/Nonemm.App/AppSession.QsySpot.cs
index 6ccf3f4..7b0bac1 100644
--- a/src/Nonemm.App/AppSession.QsySpot.cs
+++ b/src/Nonemm.App/AppSession.QsySpot.cs
@@ -28,10 +28,32 @@ public sealed partial class AppSession
         Dispatcher.UIThread.Post(() => SpotOnQsy(position, before));
     }
 
-    private void SpotOnQsy(OperatingPosition position, Frequency before)
+    /// Where the radio was when the call in each entry window was first seen.
+    /// A radio reports every few hundred hertz as the knob turns, so the move
+    /// is measured from here and not from the previous report.
+    private readonly Dictionary<OperatingPosition, (string Call, Frequency At)> heardAt = [];
+
+    private void SpotOnQsy(OperatingPosition position, Frequency reported)
     {
         string call = position.Entry.Call.Trim().ToUpperInvariant();
         Frequency now = position.Frequency;
+        if (call.Length == 0)
+        {
+            heardAt.Remove(position);
+            return;
+        }
+        if (!heardAt.TryGetValue(position, out var anchor) || anchor.Call != call)
+        {
+            anchor = (call, reported);
+            heardAt[position] = anchor;
+        }
+        if (Bands.ForFrequency(anchor.At) != Bands.ForFrequency(now))
+        {
+            // a band change starts again from the new band
+            heardAt[position] = (call, now);
+            return;
+        }
+        Frequency before = anchor.At;
         Band? band = Bands.ForFrequency(before);
         if (call.Length < ShortestCallToSpot
             || call.All(char.IsAsciiDigit)
@@ -58,6 +80,7 @@ public sealed partial class AppSession
             SpotSource.Operator,
             position.Me.Callsign,
             $"Local spot by {Settings.CurrentOperator}");
+        heardAt.Remove(position);
         Bandmap.Add(spot);
         SendSpots([spot]);
         _ = link?.SendSpotAsync(new SharedSpot(
diff --git a/src/Nonemm.App/Windows/TelnetWindow.Filters.cs b/src/Nonemm.App/Windows/TelnetWindow.Filters.cs
index 115ef3b..ecbbfc3 100644
--- a/src/Nonemm.App/Windows/TelnetWindow.Filters.cs
+++ b/src/Nonemm.App/Windows/TelnetWindow.Filters.cs
@@ -49,6 +49,7 @@ public sealed partial class TelnetWindow
         BlockedSpottersBox.Text = string.Join(' ', filter.BlockedSpotters);
         BlockedCallsBox.Text = string.Join(' ', filter.BlockedCalls);
         TimeoutBox.Text = session.Settings.SpotTimeoutMinutes.ToString(CultureInfo.InvariantCulture);
+        QsySpotBox.Text = session.Settings.QsySpotHertz.ToString(CultureInfo.InvariantCulture);
         SpotCommentBox.Text = session.Settings.SpotComment;
     }
 
@@ -72,6 +73,7 @@ public sealed partial class TelnetWindow
             },
             RandomizeSpots = RandomizeBox.IsChecked == true,
             SpotTimeoutMinutes = Minutes(TimeoutBox.Text, session.Settings.SpotTimeoutMinutes),
+            QsySpotHertz = Minutes(QsySpotBox.Text, session.Settings.QsySpotHertz),
         });
         Show("*** filters applied — they hold for the spots that arrive from now on", NoticeColour);
     }
diff --git a/src/Nonemm.App/Windows/TelnetWindow.axaml b/src/Nonemm.App/Windows/TelnetWindow.axaml
index 14f56ac..4906e4f 100644
--- a/src/Nonemm.App/Windows/TelnetWindow.axaml
+++ b/src/Nonemm.App/Windows/TelnetWindow.axaml
@@ -122,6 +122,8 @@
           <TextBox Name="BlockedCallsBox" />
           <TextBlock Classes="label" Text="Bandmap spot timeout (minutes)" />
           <TextBox Name="TimeoutBox" Width="60" HorizontalAlignment="Left" />
+          <TextBlock Classes="label" Text="Spot a call locally when the radio moves more than (Hz)" />
+          <TextBox Name="QsySpotBox" Width="60" HorizontalAlignment="Left" />
           <Button Content="Apply" Click="OnApplyFilters" Margin="0,10,0,0" />
         </StackPanel>
       </ScrollViewer>