From f0d58eac10e165a1b2f52386ea31bd44b5b3b259 Mon Sep 17 00:00:00 2001 From: Joris van Rantwijk Date: Sun, 29 Dec 2013 18:50:56 +0100 Subject: [PATCH] Reduce IF bandwidth to 100 kHz. --- Filter.cc | 2 +- FmDecode.h | 8 ++++---- main.cc | 3 +-- 3 files changed, 6 insertions(+), 7 deletions(-) diff --git a/Filter.cc b/Filter.cc index ee76185..393a0f0 100644 --- a/Filter.cc +++ b/Filter.cc @@ -276,7 +276,7 @@ void LowPassFilterRC::process(const SampleVector& samples_in, * H(s) = 1 / (1 - s * timeconst) * * Discrete domain: - * H(z) = (1 - exp(-1/timeconst)) / (1 - exp(-1/timeconst) / z)a + * H(z) = (1 - exp(-1/timeconst)) / (1 - exp(-1/timeconst) / z) */ Sample a1 = - exp(-1/m_timeconst);; Sample b0 = 1 + a1; diff --git a/FmDecode.h b/FmDecode.h index 45da9de..062d9b4 100644 --- a/FmDecode.h +++ b/FmDecode.h @@ -72,10 +72,10 @@ private: class FmDecoder { public: - static constexpr double default_deemphasis = 50; - static constexpr double default_bandwidth_if = 115000; - static constexpr double default_freq_dev = 75000; - static constexpr double default_bandwidth_pcm = 15000; + static constexpr double default_deemphasis = 50; + static constexpr double default_bandwidth_if = 100000; + static constexpr double default_freq_dev = 75000; + static constexpr double default_bandwidth_pcm = 15000; /** * Construct FM decoder. diff --git a/main.cc b/main.cc index 6dcb25e..0acf911 100644 --- a/main.cc +++ b/main.cc @@ -478,7 +478,6 @@ int main(int argc, char **argv) adjust_gain(audiosamples, 0.5); // TODO : investigate I/Q imbalance to fix Radio4 noise -// TODO : investigate if PLL receiver is better than phase discriminator at weak reception // TODO : show mono/stereo (switching) @@ -523,7 +522,7 @@ int main(int argc, char **argv) output_thread.join(); } - // TODO : cleanup + // No cleanup needed; everything handled by destructors. return 0; }