Re: [Discuss-gnuradio] where to begin

[Johnathan Corgan]

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.