The is a lot of really cool reasons for the stereo to be the way it is, check out http://transmitters.tripod.com/stereo.htm it's an amazing read.
Also the problem of no stereo signal is probably with modern music, there is not much difference between L and R anymore, just a single channel of mass produced noise, so since the're subtractive, silence is broadcast on the L-R signal, not like days past when Pink Floyd would fly you though space on both channels! On Sun, Feb 19, 2012 at 11:50 AM, Marcus D. Leech <mle...@ripnet.com> wrote: > Spent some time yesterday evening building up a stereo FM receiver in GRC. > I know there are already a few of these for broadcast FM, > but for personal education reasons, I thought I'd build something up. > > Attached is my result. > > It seems to work reasonably well (better than the existing example WFM > stereo receiver on the same signals). > > But something I've discovered is that about 30% of the program material > coming out of my fave radio station doesn't even have > any L-R signal present. I mean, I can understand during announcements, > commercials, etc. But a lot of the musical material > doesn't have any L-R, even modern material. > > But I never really knew the gory details of FM Multiplex before--didn't know > the L-R channel was DSB-SC, for example. Never had cause > to think deeply about it. I knew there was a 19kHz pilot tone, and that it > was doubled to 38kHz (usually with a PLL), but I always thought > it was used as a switching signal of some sort. > > If I get keen, I'll extend this to include RDS decoding. > > -- > Marcus Leech > Principal Investigator > Shirleys Bay Radio Astronomy Consortium > http://www.sbrac.org > > > _______________________________________________ > 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
