diff --git a/Software/PC_Application/CustomWidgets/siunitedit.cpp b/Software/PC_Application/CustomWidgets/siunitedit.cpp
index 853ba7f..ff46d12 100644
--- a/Software/PC_Application/CustomWidgets/siunitedit.cpp
+++ b/Software/PC_Application/CustomWidgets/siunitedit.cpp
@@ -5,6 +5,7 @@
 #include <QEvent>
 #include <QKeyEvent>
 #include <QDebug>
+#include <QTimer>
 
 SIUnitEdit::SIUnitEdit(QString unit, QString prefixes, int precision, QWidget *parent)
     : QLineEdit(parent)
@@ -83,6 +84,16 @@ bool SIUnitEdit::eventFilter(QObject *, QEvent *event)
     } else if(event->type() == QEvent::FocusOut) {
         parseNewValue(1.0);
         emit focusLost();
+    } else if(event->type() == QEvent::FocusIn) {
+        // online found clumsy way to select all text when clicked!?!
+        // just selectAll() alone does _not_ work!
+        QTimer::singleShot(0, this, &QLineEdit::selectAll);
+        /*
+         * However, this widget does not loose focus when clicking on a smith chart from here
+         * At the same time, clicking on x-y plot does loose focus as expected
+         * This behaviour existed before this mod, but it was not obvious due to properties of placeholdertext
+         */
+
     }
     return false;
 }
@@ -91,7 +102,8 @@ void SIUnitEdit::setValueQuiet(double value)
 {
     _value = value;
     clear();
-    setPlaceholderText(Unit::ToString(value, unit, prefixes, precision));
+    setPlaceholderText(Unit::ToString(value, unit, prefixes, precision)); // didn't remove it because maybe needed elsewhere
+    setText(Unit::ToString(value, unit, prefixes, precision));   // because selectAll() only affects setText() (placeholder text is igonred)
 }
 
 void SIUnitEdit::parseNewValue(double factor)
@@ -118,7 +130,7 @@ void SIUnitEdit::parseNewValue(double factor)
         } else {
             qWarning() << "SIUnit conversion failure:" << input;
         }
-        clear();
+//        clear();  // removed due to funny behaviour when clicking repeatedly between start, center, span, stop, but without editing anything
     }
 }
 
diff --git a/Software/PC_Application/Traces/tracewidget.cpp b/Software/PC_Application/Traces/tracewidget.cpp
index c935fd9..3e63af6 100644
--- a/Software/PC_Application/Traces/tracewidget.cpp
+++ b/Software/PC_Application/Traces/tracewidget.cpp
@@ -36,7 +36,11 @@ void TraceWidget::on_add_clicked()
 
 void TraceWidget::on_remove_clicked()
 {
-    model.removeTrace(ui->view->currentIndex().row());
+    QModelIndex index = ui->view->currentIndex();
+    if (index.isValid()) {      // if nothing clicked, index.row() = -1
+        model.removeTrace(index.row());
+        // otherwise, TraceModel casts index to unsigned int and compares with traces.size() which is int
+    };
 }
 
 bool TraceWidget::eventFilter(QObject *, QEvent *event)
diff --git a/Software/PC_Application/VNA/vna.cpp b/Software/PC_Application/VNA/vna.cpp
index d7fbcbd..1168063 100644
--- a/Software/PC_Application/VNA/vna.cpp
+++ b/Software/PC_Application/VNA/vna.cpp
@@ -171,9 +171,10 @@ VNA::VNA(AppWindow *window)
 
 
     // Sweep toolbar
+    int wid = 80;   // propose slight reduction, to fit more widgets comfortably
     auto tb_sweep = new QToolBar("Sweep");
     auto eStart = new SIUnitEdit("Hz", " kMG", 6);
-    eStart->setFixedWidth(100);
+    eStart->setFixedWidth(wid);
     eStart->setToolTip("Start frequency");
     connect(eStart, &SIUnitEdit::valueChanged, this, &VNA::SetStartFreq);
     connect(this, &VNA::startFreqChanged, eStart, &SIUnitEdit::setValueQuiet);
@@ -181,7 +182,7 @@ VNA::VNA(AppWindow *window)
     tb_sweep->addWidget(eStart);
 
     auto eCenter = new SIUnitEdit("Hz", " kMG", 6);
-    eCenter->setFixedWidth(100);
+    eCenter->setFixedWidth(wid);
     eCenter->setToolTip("Center frequency");
     connect(eCenter, &SIUnitEdit::valueChanged, this, &VNA::SetCenterFreq);
     connect(this, &VNA::centerFreqChanged, eCenter, &SIUnitEdit::setValueQuiet);
@@ -189,7 +190,7 @@ VNA::VNA(AppWindow *window)
     tb_sweep->addWidget(eCenter);
 
     auto eStop = new SIUnitEdit("Hz", " kMG", 6);
-    eStop->setFixedWidth(100);
+    eStop->setFixedWidth(wid);
     eStop->setToolTip("Stop frequency");
     connect(eStop, &SIUnitEdit::valueChanged, this, &VNA::SetStopFreq);
     connect(this, &VNA::stopFreqChanged, eStop, &SIUnitEdit::setValueQuiet);
@@ -197,7 +198,7 @@ VNA::VNA(AppWindow *window)
     tb_sweep->addWidget(eStop);
 
     auto eSpan = new SIUnitEdit("Hz", " kMG", 6);
-    eSpan->setFixedWidth(100);
+    eSpan->setFixedWidth(wid);
     eSpan->setToolTip("Span");
     connect(eSpan, &SIUnitEdit::valueChanged, this, &VNA::SetSpan);
     connect(this, &VNA::spanChanged, eSpan, &SIUnitEdit::setValueQuiet);
@@ -225,7 +226,7 @@ VNA::VNA(AppWindow *window)
     // Acquisition toolbar
     auto tb_acq = new QToolBar("Acquisition");
     auto dbm = new QDoubleSpinBox();
-    dbm->setFixedWidth(95);
+    dbm->setFixedWidth(80); // propose slight reduction, to fit more widgets when App not maximized
     dbm->setRange(-100.0, 100.0);
     dbm->setSingleStep(0.25);
     dbm->setSuffix("dbm");