Straight from USRP to Wave File

GNU Radio
1

Hello,

I wish to have a USRP source receiving at 54.1Mhz sent straight to a
stereo wave file sink with no demodulation or any other manipulation.
Side A of the USRP would record to the left channel and side B to right.
I’d like to record at 192khz 24bit if possible (and no this isn’t for a
listening application that would just be silly). Let’s just say I’m not
a crack programmer and the documentation for this things are scattered
in the wind across the internet. This is probably one of the simplest
programs you can write for gnuradio but I need some help.

Thanks!

2

On Wed, Feb 03, 2010 at 03:39:34PM -0700, Jon Paul Lundquist wrote:

internet. This is probably one of the simplest programs you can
write for gnuradio but I need some help.

Thanks!

To get that signal in, it will need to be downconverted in the FPGA.
Is your input a quadrature signal (i.e., two inputs: I & Q), or is it
two (unrelated) real signals? Which daughterboard are you planning on
using?

Take a look at usrp_rx_cfile.py for the basic framework for a single
channel (or quadrature signal). If the two inputs are independent,
gnuradio-examples/python/multi-antenna/multi_file.py may provide a
better starting point. You’ll want to use a gr.wavefile_sink to write
the wavefile.

http://gnuradio.org/doc/doxygen/classgr__wavfile__sink.html

Eric

3

Thanks for the response Eric. Each input is a separate antenna. I
believe we have the basic daughter board. So far I’ve attempted to do
this via GRC but I’m not sure how to go from the complex output of the
USRP sources to the floats needed for the wave file sink.