On Thu, 2008-08-07 at 17:24 -0700, Johnathan Corgan wrote: > rhubbell wrote: > > > You're saying use a soundcard since that would be the cheapest way? I > > didn't know that was a possibility. I'll have to explore that and look > > through the archive. Thanks for the tip. > > Just keep in mind that most audio cards have a "DC hole" due to the 20 > Hz high pass filter on their input. If you're looking for Schumann > resonances, these will be at 7-30 Hz, so it won't work. > > You can multiply your incoming signal (in the analog domain) by a sine > wave to move the frequencies off DC, then move it back down to baseband > digitally with GNU Radio. (You'll need a PLL to synchronize the mixing > frequencies.) > > I think someone has already done ELF with GNU Radio a few years ago, you > can try Google.
I will look some more than, maybe not discussed here. I notice the archive goes back only to Mon, 23 Jul 2001 16:40:38 -0700 but GNUradio has been around since 1998. So I'll have to look for those older discussions too. Thanks for the guidance. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
