Hi!
just for curiosity, i've used my VLF receiver (magnetic one) with an antenna Ferrite Philips with 10.000 turns . The freqeuncy range is from 0 to 20 kHz. Then i've connected the output of the receiver to the microphone of the pc, while the WandBoard Quad was extracting and writing new ports on the microSD card running FreeBSD 10.
http://youtu.be/lXLnpSG55fo
Best Regards
Fabrizio
http://www.sidmonitor.net
http://deltafabri.wordpress.com/