refactor fm_radio.py: remove unused attributes & some superfluous settings

fm_radio.py

@@ -25,30 +25,15 @@ class fm_radio(gr.top_block):
     def __init__(self):
         gr.top_block.__init__(self, "FM Radio Receiver", catch_exceptions=True)
 
-        # Variables
-        self.samp_rate = samp_rate = 2560000
-        self.channel_width_hertz = channel_width_hertz = 250000
-        self.audio_sample_rate_hertz = audio_sample_rate_hertz = 48000
+        samp_rate = 2560000
+        channel_width_hertz = 250000
+        audio_sample_rate_hertz = 48000
 
-        # Blocks
-        self.rtlsdr_source_0 = osmosdr.source(args="numchan=" + str(1) + " " + "")
-        self.rtlsdr_source_0.set_time_unknown_pps(osmosdr.time_spec_t())
+        self.rtlsdr_source_0 = osmosdr.source()
         self.rtlsdr_source_0.set_sample_rate(samp_rate)
         self.rtlsdr_source_0.set_center_freq((98.3 * 1e6), 0)
-        self.rtlsdr_source_0.set_freq_corr(0, 0)
-        self.rtlsdr_source_0.set_dc_offset_mode(0, 0)
-        self.rtlsdr_source_0.set_iq_balance_mode(0, 0)
-        self.rtlsdr_source_0.set_gain_mode(False, 0)
-        self.rtlsdr_source_0.set_gain(20, 0)
-        self.rtlsdr_source_0.set_if_gain(20, 0)
-        self.rtlsdr_source_0.set_bb_gain(20, 0)
-        self.rtlsdr_source_0.set_antenna("", 0)
-        self.rtlsdr_source_0.set_bandwidth(0, 0)
         self.rational_resampler_xxx_0 = filter.rational_resampler_fff(
-            interpolation=audio_sample_rate_hertz,
-            decimation=channel_width_hertz,
-            taps=[],
-            fractional_bw=0,
+            interpolation=audio_sample_rate_hertz, decimation=channel_width_hertz
         )
         self.low_pass_filter_0 = filter.fir_filter_ccf(
             (int(samp_rate / channel_width_hertz)),
@@ -60,7 +45,6 @@ class fm_radio(gr.top_block):
             audio_decimation=1,
         )
 
-        # Connections
         self.connect((self.analog_wfm_rcv_0, 0), (self.rational_resampler_xxx_0, 0))
         self.connect((self.low_pass_filter_0, 0), (self.analog_wfm_rcv_0, 0))
         self.connect((self.rational_resampler_xxx_0, 0), (self.audio_sink_0, 0))