diff --git a/NanoVNASaver/Chart.py b/NanoVNASaver/Chart.py
index a64e425..f29d6ee 100644
--- a/NanoVNASaver/Chart.py
+++ b/NanoVNASaver/Chart.py
@@ -687,7 +687,7 @@ class LogMagChart(Chart):
 
     def drawChart(self, qp: QtGui.QPainter):
         qp.setPen(QtGui.QPen(self.textColor))
-        qp.drawText(3, 15, self.name)
+        qp.drawText(3, 15, self.name + " (dB)")
         qp.setPen(QtGui.QPen(QtGui.QColor("lightgray")))
         qp.drawLine(self.leftMargin, 20, self.leftMargin, 20+self.chartHeight+5)
         qp.drawLine(self.leftMargin-5, 20+self.chartHeight, self.leftMargin+self.chartWidth, 20 + self.chartHeight)
@@ -735,6 +735,9 @@ class LogMagChart(Chart):
             y = 30 + round((i-minValue)/span*(self.chartHeight-10))
             qp.setPen(QtGui.QPen(QtGui.QColor("lightgray")))
             qp.drawLine(self.leftMargin-5, y, self.leftMargin+self.chartWidth, y)
+            if i > minValue:
+                qp.setPen(QtGui.QPen(self.textColor))
+                qp.drawText(3, y + 4, str(-i))
         qp.setPen(self.textColor)
         qp.drawText(3, 35, str(-minValue))
         qp.drawText(3, self.chartHeight+20, str(-maxValue))
@@ -833,4 +836,4 @@ class LogMagChart(Chart):
         im50 = 50 * (2 * im) / (1 + re * re + im * im - 2 * re)
         # Calculate the reflection coefficient
         mag = math.sqrt((re50 - 50) * (re50 - 50) + im50 * im50) / math.sqrt((re50 + 50) * (re50 + 50) + im50 * im50)
-        return -20 * math.log10(mag)
\ No newline at end of file
+        return -20 * math.log10(mag)
diff --git a/NanoVNASaver/NanoVNASaver.py b/NanoVNASaver/NanoVNASaver.py
index a28a0bd..09582ab 100644
--- a/NanoVNASaver/NanoVNASaver.py
+++ b/NanoVNASaver/NanoVNASaver.py
@@ -982,16 +982,21 @@ class NanoVNASaver(QtWidgets.QWidget):
 
     def loadReferenceFile(self):
         filename = self.referenceFileNameInput.text()
-        t = Touchstone(filename)
-        t.load()
-        self.setReference(t.s11data, t.s21data, filename)
+        if filename is not "":
+            self.resetReference()
+            t = Touchstone(filename)
+            t.load()
+            self.setReference(t.s11data, t.s21data, filename)
 
     def loadSweepFile(self):
         filename = self.referenceFileNameInput.text()
-        t = Touchstone(filename)
-        t.load()
-        self.saveData(t.s11data, t.s21data, filename)
-        self.dataUpdated()
+        if filename is not "":
+            self.data = []
+            self.data21 = []
+            t = Touchstone(filename)
+            t.load()
+            self.saveData(t.s11data, t.s21data, filename)
+            self.dataUpdated()
 
     def sizeHint(self) -> QtCore.QSize:
         return QtCore.QSize(1100, 950)
diff --git a/NanoVNASaver/Touchstone.py b/NanoVNASaver/Touchstone.py
index 2d3106f..bc24397 100644
--- a/NanoVNASaver/Touchstone.py
+++ b/NanoVNASaver/Touchstone.py
@@ -31,6 +31,7 @@ class Touchstone:
     def load(self):
         self.s11data = []
         self.s21data = []
+        factor = 1
         try:
             file = open(self.filename, "r")
 
@@ -44,6 +45,19 @@ class Touchstone:
                     # Check that this is a valid header
                     if l == "# Hz S RI R 50":
                         parsed_header = True
+                        factor = 1
+                        continue
+                    elif l == "# kHz S RI R 50":
+                        parsed_header = True
+                        factor = 10**3
+                        continue
+                    elif l == "# MHz S RI R 50":
+                        parsed_header = True
+                        factor = 10**6
+                        continue
+                    elif l == "# GHz S RI R 50":
+                        parsed_header = True
+                        factor = 10**9
                         continue
                     else:
                         # This is some other comment line
@@ -53,24 +67,20 @@ class Touchstone:
                     continue
 
                 try:
-                    if l.count(" ") > 2:
-                        freq, re11, im11, re21, im21, _ = l.split(maxsplit=5)
-                        freq = int(freq)
-                        re11 = float(re11)
-                        im11 = float(im11)
+                    values = l.split(maxsplit=5)
+                    freq = values[0]
+                    re11 = values[1]
+                    im11 = values[2]
+                    freq = int(float(freq) * factor)
+                    re11 = float(re11)
+                    im11 = float(im11)
+                    self.s11data.append(Datapoint(freq, re11, im11))
+                    if len(values) > 3:
+                        re21 = values[3]
+                        im21 = values[4]
                         re21 = float(re21)
                         im21 = float(im21)
-                        self.s11data.append(Datapoint(freq, re11, im11))
                         self.s21data.append(Datapoint(freq, re21, im21))
-                    elif l.count(" ") == 2:
-                        freq, re11, im11 = l.split()
-                        freq = int(freq)
-                        re11 = float(re11)
-                        im11 = float(im11)
-                        self.s11data.append(Datapoint(freq, re11, im11))
-                    else:
-                        print("Warning: Read a line with not enough values: " + l)
-                        continue
                 except ValueError as e:
                     print("Error parsing line " + l + " : " + str(e))