Just a quick note that Gqrx now uses pulseaudio for all audio I/O, which includes I/Q input from the Funcube Dongle.
One of the great advantages of software defined radio receivers is that tuning receiver settings is a matter of adjusting software parameters. Gqrx is no different here and has optimal settings built in for weather satellite reception. This tutorial describes how to receive automatic picture transmissions (APT) from NOAA weather satellites using Gqrx SDR, record them to a WAV file, and finally decode the images using the free and open source Atpdec decoder. If you follow this guide you can end up with very nice results such as the one shown at the end.
Few weeks ago, or maybe a month or two – I don’t remember, I spent an afternoon trying to build gnuradio-core and gr-audio on Mac OS X without using any macports. It was a casual an undocumented attempt that resulted in a compilation failure. I wasn’t surprised because I made several mistakes along the way, so I just left it an moved on.
FM traffic and packet radio from the AO-27 amateur radio satellite. I made this recording last Saturday while testing the Gqrx software receiver using the cross yagis at OZ7SAT and the Funcube Dongle.
Please visit the new Gqrx website. The information on this page is no longer updated!
Gqrx is a software defined radio receiver for Funcube Dongle (FCD), RTL2832U-based DVB-T devices (RTL-SDR), Universal Software Radio Peripherals (USRP) and Osmo SDR devices. It is powered by GNU Radio and the Qt GUI toolkit.
Yesterday I successfully received APRS transmissions from the International Space Station on 145.825 MHz using my Yaesu FT-817 connected to my MacBook Pro via a Signalink audio interface and a USB sound adapter.
Last week I started on a new experiment trying to integrate the AFSK1200 demodulator code from multimon into a simple Qt-based graphical application. This experiment had two objectives:
- Test the feasibility of integrating the AFSK1200 demodulator from multimon into other applications.
- Try using the QAudio framework from Qt for audio I/O that should work on both Linux, Windows and Mac OS X.
With both the frequency controller and FFT plot widgets in place gqrx was ready for the first on the air tests. The video below shows the first reception of the AO-27 amateur radio satellite during orbit 92436 and 92437, using the Funcube Dongle receiver that I use for portable space communication.
Following my success with integrating the frequency control widget from cutesdr into gqrx I have decided to try the same with the FFT plot and waterfall widget. This too seemed to be a single C++ class that might be easy to integrate into my experimental software receiver powered by GNU Radio and Qt GUI.
Gqrx / C++ update June 4, 2011: After establishing the basic framework for a GNU Radio receiver written in C++ it was time to start working on the GUI framework. As you may recall the GUI will be written in Qt and I am hoping that it will simplify porting the application to Mac OS X.