I found a bug with de-emphasis, the coefficients in de denominator should change their sign in gnuradio....
One question. I have tried your simple_fm_rcv and a similar version that I made on my own. In both cases I have found that there is a phase shift in the pilot tone. In the image the red curve is the L-R modulated signal and the green line is the recovered 38Khz carried recovered after squaring the pilot tone. It looks like the zero crossings are pi/2 rad shifted so the demodulated signal is almost zero. <http://gnuradio.4.n7.nabble.com/file/n42875/Screen_Shot_2013-08-01_at_6.04.35_PM.png> By delaying the pilot by one sample (which is almos pi/2) the problem solves, but I do not see any reason for doing this :-( Of course, I have been careful and all the filters to split the mux signal have the same delay and have linear phase Any idea? -- View this message in context: http://gnuradio.4.n7.nabble.com/Sample-audio-from-my-FM-stereo-receiver-tp1897p42875.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
