-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 A shoot, I overlooked the 64 decimation rate... Sorry about that.
On 25.04.2014 17:36, Anton Komarov wrote: > Marcus, w/o AGC audio sometimes is creapy. I have tested AGC2, > tried to play with attack and decay, but at last when there is a > plane in the vicinity dongle overloads and sound become very loud. > Then i tested FAGC and it fits well! 1024M/64 gives 16k and 256 > samples equals - 62 ms of signal. Works ok for me. > > > On Fri, Apr 25, 2014 at 7:25 PM, Marcus Müller <mar...@hostalia.de> > wrote: > > 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 >>>> >> >> _______________________________________________ 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/ iQEbBAEBAgAGBQJTWoU1AAoJEBQ6EdjyzlHtQAYH+KNwTI+XPjKFyb+kId+Y9fxv uthK+LH7CTAm85j9gb4mIeGe7Wpe2gZZ0sqvDgyXL594urUSvfbmyCy/p0GI7WfC evmwyX4HBZIuXBdqIkj0NdhvwpaBHBYUE1R2JfVIK1ZqaApNtGVxoKpOyI38XCg1 m68tsU3HASfVQxIWfuJS0mBgwPo8wSCTXLOoUqc1YTVXd+tXNNAVLbFEDUOgVuib irkUhUYdNi85SwO3ildun/9xEwXB3g4FeB3Hq66TccE5M7zvZsOBa4oF/uKITRoG cvOc/EuBRCG+u1lI2owwQXsUuGWmHhN+xcjtkzn4Qa+2b+zR9bPPGS70ru45vQ== =+L1B -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
