Experimental AM, FM and SSB software receiver implemented using GNU Radio and Qt GUI toolkit.

This branch contains the UHD version of the receiver.

To run this application you need to have GNU Radio 3.3 with gr-qtgui component installed, as well as a USRP or other device supported by UHD.

Implemented functions:
 * Set USRP frequency, RF gain and bandwidth (250k, 500k, 1M, 2M or 4M)
 * Select USRP subdevice and antenna on the command line
 * Show USRP spectrum
 * Variable bandpass filter
 * AM, SSB, FNN and FMW demodulators
 * AGC in AM and SSB modes
 * One click recording of audio into .wav file and playback of last recorded audio file

To start the receiver execute the gqrx.py Python script. Use -h to see a list of command line options.

If you have problems with audio while changing receiver settings at runtime you can try to apply this patch: https://gist.github.com/664132 (this fix has been included in GNU Radio since December 2010).

I have also made some modifications to the gr-qtgui code in order to enable grid, have nicer colors and take up less vertical space to better fit on laptop screens. These changes are available in this patch: https://gist.github.com/668462. This is not mandatory though, just part of the experiment.

You can modify the GUI by opening the gqrx_qtgui.ui file in Qt Designer. If you make changes you have to recompile the UI code using:

pyuic4 gqrx_qtgui.ui -o gqrx_qtgui.py