Re: [Discuss-gnuradio] Tuning in VLF with a sound card

[address@hidden]

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017RS006420
or
http://jmfriedt.free.fr/agu_dcf77.pdf
We are currently working on simultaneously decoding (e)LORAN/MSF, TDF & DCF77 
v.s GPS
with a sound card.

JM

--
JM Friedt, FEMTO-ST Time & Frequency/SENSeOR, 26 rue de l'Epitaphe,
25000 Besancon, France

May 2, 2019 10:24 PM, "Brad Hein" <address@hidden> wrote:

> I took a Raspberry Pi and attached a 48KHz USB sound card, with a big 
> magnetic loop antenna fed
> into the mic. A little cheesy? yes! But I'd like to try and see if I can 
> receive VLF. It's in a
> remote location with little to no interference so I'm thinking my chances 
> should be good. The
> challenge I'm facing is that I need to write the SDR logic to "tune" 
> throughout the 0-24KHz tuning
> range.
> 
> My question is, being that a sound card source presents samples in float and 
> not the usual complex
> data type, can I still apply the same SDR logic that we use for SSB/FM/AM 
> demodulation such as
> those presented in the Gnuradio tutorials (eg.
> http://www.csun.edu/~skatz/katzpage/sdr_project/sdr/grc_tutorial3.pdf) and if 
> not, how do I go
> about translating the float input into something I can use to feed existing 
> AM/FM/SSB demodulator
> flowgraphs?
> 
> I run many other flowgraphs on Raspberry Pi's remotely so the networking and 
> remote aspect of the
> project will be easy for me. I really just need some initial guidance knowing 
> which direction to go
> in terms of tuning.
> 
> Thanks!
> Brad