[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Sample audio from my FM stereo receiver
From: |
Alberto Albiol |
Subject: |
Re: [Discuss-gnuradio] Sample audio from my FM stereo receiver |
Date: |
Thu, 1 Aug 2013 09:08:53 -0700 (PDT) |
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.
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: [Discuss-gnuradio] Sample audio from my FM stereo receiver,
Alberto Albiol <=