reduce sample rate to get rid of crackling

fm_radio.grc

@@ -69,7 +69,7 @@ blocks:
   id: variable
   parameters:
     comment: ''
-    value: '2000000'
+    value: '1800000'
   states:
     bus_sink: false
     bus_source: false

fm_radio.py

@@ -77,7 +77,7 @@ class fm_radio(gr.top_block, Qt.QWidget):
         # Variables
         ##################################################
         self.volume = volume = 0.5
-        self.samp_rate = samp_rate = 2000000
+        self.samp_rate = samp_rate = 1800000
         self.frequency_mhz = frequency_mhz = 98.3
         self.down_rate_hertz = down_rate_hertz = 250000