About a year ago I posted a step-by-step guide about how to receive NOAA APT weather satellite images using Gqrx SDR and the Funcube Dongle. Today, I tried to repeat the procedure using my ezcap eztv666 rtlsdr dongle with very good results.
Support for RTL2832U-based DVB-T devices is available via the rtl-sdr and gr-osmosdr libraries. This also provides support for Ettus Research USRP’s if the gr-uhd package has been installed prior to compiling gr-osmosdr. A complete build from scratch that would support all hardware devices would thus include the following steps:
I have previously written about interference from FM stations on the HO-68 linear transponder. Now it appears the other satellites with linear transponders also suffer from local FM traffic by people who haven’t got a clue that they are transmitting in the satellite uplink segment of the 2 meter band.
Here is a new recording showing an updated Gqrx receiving the FO-29 amateur radio satellite using the Funcube Dongle. Previous recordings used an early version of Gqrx. It was a very quiet pass, most notable thing was probably the Russian and Spanish hams using FM. They probably don’t have a clue that their signal comes over a satellite transponder. Another video recording focusing on the FM transmissions during this FO-29 pass is available here.
I don’t think I ever posted a video showing the built-in AFSK1200 demodulator and decoder in Gqrx, so here it is. The video show local APRS traffic in Copenhagen on a Sunday afternoon. I also tried to receive from the ISS but nothing heard this time.
I was playing with my Funcube Dongle last Saturday testing Gqrx for the long awaited 2.0 release. I was using the Funcube Dongle together with the shortwave converter I got some time ago and a 5 meter long wire attached via an antenna tuner. Amongst all the traffic there is on shortwaves I recorded these two transmissions: UVB-76 aka. The Buzzer, and whistle like signal believed to be a radar in Israel.
Last week I have tested the RTL2832U-based ezcap EzTV666 DVB-T dongle on the air using various VHF signal.
RTL2832U-based DVB-T dongles are now supported by Gqrx SDR, see this announcement!
You may have noticed the recent buzz on the internet about using cheap DVB-T dongles as software defined radio receivers. It all started on this mailing list when V4L/DVB kernel developer Antti Palosaari discovered that the ezcap EzTV 668 DVB-T/FM/DAB USB dongle, which is based on the RTL2832U chip, can be used to stream raw I/Q samples to the host computer. It is in fact the way the device supports FM and DAB reception; raw I/Q is sent to the host where the application does the demodulation.
Just a quick note that Gqrx now uses pulseaudio for all audio I/O, which includes I/Q input from the Funcube Dongle.
I am happy to inform all users of the Funcube Dongle and GNU Radio, that the gr-fcd driver is now included in the GNU Radio source tree. You can read the announcement here.
This change will be available in the next GNU Radio release, which I think will be 3.5.3, however, if you pull the code from the GNU Radio git repository the changes are already in your tree. Before you upgrade please remove any earlier installations of gr-fcd to avoid conflicting versions of the library.
My repository on Github will no longer be maintained and any future development of gr-fcd will be done within the scope of the GNU Radio project. I hope this will ensure better integration, more maintainers, more testing and easier installation process.