From 4b70c5a0b0bad89846ab301057643e529d009750 Mon Sep 17 00:00:00 2001 From: Nick Foster Date: Thu, 23 Aug 2012 19:21:09 -0700 Subject: [PATCH] Up the sample rate for RTL dongles to 3.2Msps. Seems to enjoy 3.2Msps just fine, and the Mode S RX works *much* better with the extra bandwidth. --- apps/modes_gui | 8 ++++---- apps/modes_rx | 6 +++--- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/apps/modes_gui b/apps/modes_gui index 5cbd127..11fb98a 100755 --- a/apps/modes_gui +++ b/apps/modes_gui @@ -178,7 +178,7 @@ class mainwindow(QtGui.QMainWindow): self.ui.stack_source.setCurrentIndex(0) elif sourceid == "RTL-SDR": - self.rates = [2.4e6] + self.rates = [3.2e6] self.antennas = ["RX"] self.ui.combo_ant.setEnabled(False) self.ui.combo_rate.setEnabled(False) @@ -381,7 +381,7 @@ class adsb_rx_block (gr.top_block): elif options["source"] == "RTL-SDR": import osmosdr self.u = osmosdr.source_c() - self.u.set_sample_rate(2.4e6) #fixed for RTL dongles + self.u.set_sample_rate(3.2e6) #fixed for RTL dongles rate = int(4e6) self.u.set_gain_mode(0) #manual gain mode self.u.set_gain(int(options["gain"])) @@ -400,8 +400,8 @@ class adsb_rx_block (gr.top_block): self.slicer = air_modes.modes_slicer(int(rate), queue) if use_resampler: - self.lpfiltcoeffs = gr.firdes.low_pass(1, 5*2.4e6, 1.2e6, 300e3) - self.resample = blks2.rational_resampler_ccf(interpolation=5, decimation=3, taps=self.lpfiltcoeffs) + self.lpfiltcoeffs = gr.firdes.low_pass(1, 5*3.2e6, 1.6e6, 300e3) + self.resample = blks2.rational_resampler_ccf(interpolation=5, decimation=4, taps=self.lpfiltcoeffs) self.connect(self.u, self.resample, self.demod) else: self.connect(self.u, self.demod) diff --git a/apps/modes_rx b/apps/modes_rx index 7db6e6a..7d13265 100755 --- a/apps/modes_rx +++ b/apps/modes_rx @@ -82,7 +82,7 @@ class adsb_rx_block (gr.top_block): elif options.rtlsdr: #RTLSDR dongle import osmosdr self.u = osmosdr.source_c(options.args) - self.u.set_sample_rate(2.4e6) #fixed for RTL dongles + self.u.set_sample_rate(3.2e6) #fixed for RTL dongles if not self.u.set_center_freq(options.freq): print "Failed to set initial frequency" @@ -118,8 +118,8 @@ class adsb_rx_block (gr.top_block): self.slicer = air_modes.modes_slicer(rate, queue) if use_resampler: - self.lpfiltcoeffs = gr.firdes.low_pass(1, 5*2.4e6, 1.2e6, 300e3) - self.resample = blks2.rational_resampler_ccf(interpolation=5, decimation=3, taps=self.lpfiltcoeffs) + self.lpfiltcoeffs = gr.firdes.low_pass(1, 5*3.2e6, 1.6e6, 300e3) + self.resample = blks2.rational_resampler_ccf(interpolation=5, decimation=4, taps=self.lpfiltcoeffs) self.connect(self.u, self.resample, self.demod) else: self.connect(self.u, self.demod)