The Ettus USRP B210 is an advanced $1,100 software defined radio that is capable of both transmit and receive. Balint, one of the researchers at Ettus, has posted a video showing how he was able to play a light hearted prank on some of his colleagues using the B210.
Tyler Watt has posted over on his blog a new post showing some tips on the use of SDR#. He makes use of animated gifs to clearly show the action in SDR# that he is performing. If you’ve been wanting to learn more about how to use SDR#, or what the various options do, check out his guide.
To do this he used the RTL-SDR Scanner software which allows you to create a composite spectrum over a frequency range wider than the maximum 3.2 MHz of bandwidth the RTL-SDR provides. The wideband noise generator was cleverly constructed out of a diode operating in it’s reverse breakdown mode.
Apart from the obvious excessive spurs, this method worked quite well and the shape of the filter is clearly visible.
In Boulder, Colorado (and possibly other US cities) there is a radio based weather monitoring system known as ‘Urban Drainage and Flood Control’. This is a system that monitors rainfall and other weather information and transmits data using the ALERT protocol.
Using his RTL-SDR and GQRX, he made a recording of some of the weather station packets on that frequency. Next he used a command line utility called minimodem to convert the recorded packets into binary data. After looking up the protocol online, he was then able to understand the binary string and extract the station ID information from it. Cparker then went on to write code that would plot the received stations on a map by cross referencing the station ID with a website containing location information about these sensors. Finally, he managed to get the whole system running live on a Raspberry Pi.
Now an rtl-sdr.com reader has written in to let us know that this concept has also been used before to create a 1 – 250 MHz FM transmitter using the Raspberry Pi and a program called PiFM. It uses the same concept of connecting a wire antenna to one of the GPIO pins but modulates the frequency using hardware on the Rpi meant to generate spread spectrum clock signals. It is claimed that it can transmit up to 50m away.
Below we show an example YouTube video of the Raspberry Pi FM radio transmitting to an RTL-SDR running HDSDR.
This software along with a supported USB software defined radio turns your Android device to a portable weather radio.
Current Features: * Listen to weather radio in the US/Canada. * Decode EAS Alerts US/Canada * Selectable Pre-defined Frequencies * Alert Notifications * Widget to display alerts * Option to unmute audio when alert recieved * FIPS and CLC Location Code Databases * Event Code Database * No internet connection required
Possible future features * Switch to using rtl_tcp_andro * Option to only show alerts if you are currently in the affected region * Affected region map
Last month two new SDR# plugins where released on rtl-sdr.ru. The first is TimeShift SDR. This plugin creates a buffer which allows you to listen to any signal at any point in time on the waterfall within the buffer time. It is very useful for catching signals that you might have otherwise missed by being too slow to click on them. Update: Turns out Timeshift SDR isn’t exactly new. But it has recently been updated to work on the latest SDR# releases.
Michele from Michele’s GNSS blog has posted his results with using a modified R820T RTL-SDR with Temperature Controlled Oscillator (TCXO) for GPS reception and decoding. The RTL-SDR is capable of tracking GPS even without TCXO but improved performance can be expected with a more stable oscillator. He notes that the R820T with it’s 3.57 MHz IF is ideally suited for GPS reception when combined with an active GPS antenna. Using this setup he was able to track GPS satellites and the Galileo E1B/C GNSS satellites as well.
Michele modified his R820T RTL-SDR with a 28.8 MHz TCXO he obtained from a friend. It is however possible to purchase modified TCXO R820T dongles directly from the 1090mhz webstore.