diff --git a/src/urh/simulator/Simulator.py b/src/urh/simulator/Simulator.py
index d9467a75a6..4083201a9d 100644
--- a/src/urh/simulator/Simulator.py
+++ b/src/urh/simulator/Simulator.py
@@ -323,7 +323,7 @@ def process_message(self):
             self.last_sent_message = msg
         else:
             # we have to receive a message
-            self.log_message("<i>Waiting for message {}</i>".format(msg.index()))
+            self.log_message("Waiting for message {}...".format(msg.index()))
             sniffer = self.sniffer
             if sniffer is None:
                 self.log_message("Fatal: No sniffer configured")
@@ -334,6 +334,7 @@ def process_message(self):
             max_retries = self.project_manager.simulator_retries
             while self.is_simulating and not self.simulation_is_finished() and retry < max_retries:
                 received_msg = self.receive_message(sniffer)
+                self.log_message("  Received {} data bits".format(len(received_msg)))
 
                 if not self.is_simulating:
                     return
@@ -353,7 +354,7 @@ def process_message(self):
                 received_msg.decoder = new_message.decoder
                 received_msg.message_type = new_message.message_type
 
-                self.log_message("Message {}: Check whether received data matches".format(msg.index()))
+                self.log_message("  Check whether received data matches")
                 check_result, error_msg = self.check_message(received_msg, new_message, retry=retry,
                                                              msg_index=msg.index())
 
diff --git a/src/urh/ui/painting/FFTSceneManager.py b/src/urh/ui/painting/FFTSceneManager.py
index b6d08a987f..53831d7864 100644
--- a/src/urh/ui/painting/FFTSceneManager.py
+++ b/src/urh/ui/painting/FFTSceneManager.py
@@ -33,11 +33,9 @@ def show_scene_section(self, x1: float, x2: float, subpath_ranges=None, colors=N
 
     def init_scene(self, draw_grid=True):
         self.scene.draw_grid = draw_grid
-        minimum = -4.5
-        maximum = 2
 
         self.peak = self.plot_data if len(self.peak) < self.num_samples else np.maximum(self.peak, self.plot_data)
-        self.scene.setSceneRect(0, minimum, self.num_samples, maximum - minimum)
+        self.scene.setSceneRect(0, -5, self.num_samples, 10)
 
     def clear_path(self):
         for item in self.scene.items():
diff --git a/src/urh/ui/painting/GridScene.py b/src/urh/ui/painting/GridScene.py
index 7b25699a9b..397393d86d 100644
--- a/src/urh/ui/painting/GridScene.py
+++ b/src/urh/ui/painting/GridScene.py
@@ -1,5 +1,5 @@
 import numpy as np
-from PyQt5.QtCore import QRectF, QLineF, QPointF
+from PyQt5.QtCore import QRectF, QLineF, QPointF, Qt
 from PyQt5.QtGui import QPainter, QFont, QFontMetrics, QPen, QTransform, QBrush
 
 from urh import settings
@@ -16,10 +16,9 @@ def __init__(self, parent=None):
         self.frequencies = []
         self.frequency_marker = None
         super().__init__(parent)
-        self.setSceneRect(0,0,10,10)
+        self.setSceneRect(0, 0, 10, 10)
 
     def drawBackground(self, painter: QPainter, rect: QRectF):
-        # freqs = np.fft.fftfreq(len(w), 1 / self.sample_rate)
         if self.draw_grid and len(self.frequencies) > 0:
             painter.setPen(QPen(painter.pen().color(), 0))
             parent_width = self.parent().width() if hasattr(self.parent(), "width") else 750
@@ -39,29 +38,30 @@ def drawBackground(self, painter: QPainter, rect: QRectF):
             bottom = rect.bottom() - (rect.bottom() % y_grid_size)
             right_border = int(rect.right()) if rect.right() < len(self.frequencies) else len(self.frequencies)
 
+            scale_x, scale_y = util.calc_x_y_scale(rect, self.parent())
+
+            fh = self.font_metrics.height()
             x_range = list(range(x_mid, left, -x_grid_size)) + list(range(x_mid, right_border, x_grid_size))
-            lines = [QLineF(x, rect.top(), x, bottom) for x in x_range] \
+            lines = [QLineF(x, rect.top(), x, bottom-fh*scale_y) for x in x_range] \
                     + [QLineF(rect.left(), y, rect.right(), y) for y in np.arange(top, bottom, y_grid_size)]
 
+            pen = painter.pen()
+            pen.setStyle(Qt.DotLine)
+            painter.setPen(pen)
             painter.drawLines(lines)
-            scale_x, scale_y = util.calc_x_y_scale(rect, self.parent())
-
             painter.scale(scale_x, scale_y)
             counter = -1  # Counter for Label for every second line
 
             for x in x_range:
                 freq = self.frequencies[x]
                 counter += 1
+                if freq == 0:
+                    counter = 0
 
-                if freq != 0 and (counter % 2 != 0): # Label for every second line
+                if freq != 0 and (counter % 2 != 0):  # Label for every second line
                     continue
 
-                if freq != 0:
-                    prefix = "+" if freq > 0 else ""
-                    value = prefix+Formatter.big_value_with_suffix(freq, 2)
-                else:
-                    counter = 0
-                    value = Formatter.big_value_with_suffix(self.center_freq)
+                value = Formatter.big_value_with_suffix(self.center_freq + freq, 2)
                 font_width = self.font_metrics.width(value)
                 painter.drawText(QPointF(x / scale_x - font_width / 2, bottom / scale_y), value)