Here is a short demo showing how to receive broadcast FM with Gqrx. This demo uses the Funcube Dongle, which is really not suited for broadcast FM reception. Gqrx does not employ any tricks to make it sound like it works properly – it just does straightforward FM demodulation with wide FM parameters and you will hear the lack of sufficient bandwidth as distortion on some stations (not all though).
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.
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 The information on this page is no longer updated!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.
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.
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.
About a week ago I resumed working on GQRX – an experimental AM/FM/SSB software receiver powered by GNU Radio and using Qt for user interface. This time, however, I am not going to continue working on the Python receiver but create a new receiver from scratch written in C++. It will support Funcube Dongle and USRP/UHD devices.
Qthid is simple cross platform controller application for the Funcube Dongle Pro and Pro+ software defined radio receivers. It is written using the HID API library and the Qt GUI toolkit. It is a fork and evolution of the qthid002.zip package by Howard Long, G6LVB, available on the Funcube Dongle download page.
Qthid is free (libre) software licensed under the GNU General Public License. This allows you to copy, modify and distribute the software without any restrictions, provided that your modification are distributed under a compatible license.
The current stable release v4.0 provides full support for the Funcube Dongle API available with firmware 18f or later:
- Change frequency and apply frequency correction.
- Change RF gains and filters.
- Change IF gains and filters.
- LNA enhancement, bias current, etc.
- I/Q correction.
- Auto-repeat tuning buttons (click and hold button to scan).
- Variable frequency step.
- Upgrade and verify the firmware.
- The crashes and freezes in the original qthid002 have been eliminated (I hope).
- Tested on Mac OS X and Linux (32 and 64 bit).
- Use of v3.0 and later requires firmware 18f or later. Use v2.2 to upgrade earlier firmwares.
- Works on Mac OS X 10.7 Lion and Windows 7.
There is also a quick-hack release v4.1 that supports the new Funcube Dongle Pro+ devices. This does not work with the original Funcube Dongle Pro!
Download and Install
If you are using Debian or Ubuntu Linux you can try to install the Debian package available for wheezy (testing) or sid (unstable). These packages contain everything to set up and configure your Funcube Dongle.
For other systems you can try my pre-compiled binary packages available in the download section at SourceForge. You will also find source packages there. Regardless of which option you try, be sure to read the README.txt file.
The latest development code is available directly from my Github repository:
git clone git://github.com/csete/qthid.git
(Note that in order to get the Pro+ code you need to switch to the “fcdpp” branch.)
If you have a Github account you can fork it directly in Github and our repositories will be part of the same network. See the Pro Git manual for other awesome things you can do with the git repository.
Help and Support
I recommend to use the FCDevelopment Yahoo group if you have an original Pro device or the FCD Pro Plus Yahoo group if you have the newer Pro+ device. Pretty much everybody who knows something about the Funcube Dongle and the software API is there. Alternatively, you can post a comment to this page. I any case I prefer public forum for troubleshooting so that there is a record for future reference.
It looks like Moe Wheatley, AE4JY, is working on a cross platform software defined radio receiver intended for SDR hardware from RFSPACE. It is written using the Qt toolkit and will be available soon under an open source license with the purpose of providing an SDR interface program example for other developers. It is still very early and no code has been released yet, but you can watch this first demo video published few days ago and you can also join the CuteSDR Yahoo group if you are interested in following the project.