-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Actually I'm a little confused - Is seeing an AGC in an AM demodulator something you usually do? Especially the feedforward AGC should be rather err jumpy with a scope of but 256 samples, unless I'm missing something; f_sample seems to be 1024ksps, thus 256 samples max search and rescaling should behave very badly if there are baseband signal contents below 4kHz -- and that should be the case for audio, usually?
Greetings, Marcus On 25.04.2014 16:03, Marcus Leech wrote: > An AM demodulator is a squaring function. It can only *ever* > produce positive values. You can remove DC offset by using a > high-pass filter after it. on Apr 25, 2014, *Anton Komarov* > <anton.koma...@gmail.com> wrote: > > But when we have only positive values that means in fact we have > 0.5 DC offset, and that is bad. Moreover i've made test recording > with GQRX - waveform is fine! Looking into the code, nothing > special, am demod->low-pass->wav-sink. > > -- public PGP key http://pastebin.com/dqZqgyVE > > > On Fri, Apr 25, 2014 at 5:11 PM, Michael Ossmann <m...@ossmann.com > <mailto:m...@ossmann.com>> wrote: > > On Fri, Apr 25, 2014 at 04:14:30PM +0400, Anton Komarov wrote: >> >> Hi, you can find in attach AM demodulator grc file. Everything >> is straight forward with demod but audio file generated looks >> weird. Only positive values of amplitude. > The particular definition of "amplitude" adopted by GNU Radio (and > pretty much everyone else in SDR as far as I know) is "absolute > value". It is correct for it to always be positive. > > > -------------------------------------------------------------------------------- > > _______________________________________________ Discuss-gnuradio > mailing list Discuss-gnuradio@gnu.org > <mailto:Discuss-gnuradio@gnu.org> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ Discuss-gnuradio > mailing list Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTWn5MAAoJEBQ6EdjyzlHtWSEIAKSNLkujZEL/lpmy/CBrK76+ 144zh4QY9QkAd9jgYHE/lSp6oAP2EEIXI7xQw1AC+2c2c2+pcG92ydJs/2/pvEa3 zfyVUtSr5e8qByokifDCq1HeMFG4q5Uis/cNgWlQPBeWR5My6ngnE3xC4TmMhGO6 WCYFqyrf7dz+P/cXClRs9jIVv4HKPLCZky9qdmG/9rXFxovQt369boaXDdvtc6Ga dnNswR2zXh63IH+ZWaARTiB61GJ/oPw/yh1jL9inVOFhioZstUFK0xS1ACxFZBiY P1nHuixHkGXmIp6jp1QXo6H9QAqVZ5z/H4Tngd8EM+i+KsqxaJncvzGW7MVgaQA= =XADd -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
