A few people have been asking for a RTL-SDR.com V3 data/info sheet, so we have written one up here (PDF). The datasheet explains the improvements made to the V3, and how to use some of the special features like the direct sampling mode and the bias tee.
Most of the same information is available on the product release page, and the online V3 users guide as well.
The KiwiSDR is a 14-bit wideband RX only HF software defined radio created by John Seamons (ZL/KF6VO) which has up to 32 MHz of bandwidth, so it can receive the entire 10 kHz – 30 MHz VLF/LF/MW/HF spectrum all at once. However, it is not a typical SDR as you do not connect the KiwiSDR directly to your PC. Instead the KiwiSDR is a cape (add on board) for the Beaglebone single board computing platform. If you’re unfamiliar with the Beaglebone, it is a small computing board that is similar to a Raspberry Pi. The KiwiSDR is designed to be a low cost standalone unit that runs 24/7, connects to your HF antenna and internet network, and shares your 10 kHz – 30 MHz reception over the internet with up to 4 simultaneous users.
The KiwiSDR kit retails for $299 USD (Amazon) (Direct from Seeed Studio), and with that price you get the KiwiSDR cape, a Beaglebone Green board, an enclosure, microSD card and a GPS antenna. If you already have a Beaglebone lying around, then you can purchase the KiwiSDR board only for $199 USD.
Because the KiwiSDR is a network SDR, instead of connecting it to your PC it connects to your home internet network, allowing you to access it from any computing device via a web browser. Direct access to the SDR is not possible (actually it seems that it is, but it’s not easy to do), and all the computing is performed on the KiwiSDR’s on board FPGA and Beaglebone’s CPU before being sent to the network. Thus raw ADC or IQ data is never touched by your PC, your PC only sees the compressed audio and waterfall stream. So a powerful computer is not required to run the SDR. In fact, a mobile phone or tablet will do just fine.
In comparison, a $299 USD wideband non-networked SDR such as the LimeSDR uses a 12-bit ADC and can do up to 80 MHz of bandwidth over USB 3.0. But even on our relatively powerful PC (i7-6700 CPU, Geforce GTX 970 and 32 GB RAM) the LimeSDR can only get up to about 65 MHz on SDR-Console V3 before performance becomes too choppy.
But the real reason to purchase a KiwiSDR is that it is designed to be shared and accessed over the internet from anywhere in the world. You can connect to over 137 shared KiwiSDRs right now over at sdr.hu which is a site that indexes public KiwiSDRs. To achieve internet sharing, the KiwiSDR runs a modified version of András Retzler’s OpenWebRX software. OpenWebRX is similar to WebSDR, but is open source and freely available to download online. The standard OpenWebRX is also designed to support the RTL-SDR. Of course if you don’t want to share your receiver over the internet you don’t have to, and you could use it on your own local network only.
Some applications of the KiwiSDR might include things like: setting up a remote receiver in a good noise free location, helping hams give themselves propagation reports by accessing a remote KiwiSDR while they are TXing, listening to shortwave stations, monitoring WSPR or WEFAX channels, education, crowd sourced science experiments and more.
Over on YouTube user radiosification has uploaded a video tutorial that shows how to decode, follow and listen to NXDN/IDAS trunking radio signals. NXDN/IDAS is a narrowband digital voice protocol commonly used with handheld radio terminals.
In the tutorial radiosification explains how to set up DSDPlus and its frequencies text file to automatically listen to and track conversations using the control channel. SDR# is initially used to find the NXDN control and voice channels, which are then entered into the text file. Using this method only DSDPlus and its corresponding receiver FMP is used. Trunking software like Unitrunker is not needed.
Radiosification also notes that the method he presents can also be used for other digital trunking systems such as P25 as well.
All electronic devices emit some sort of unintentional RF signals which can be received by an eavesdropping radio. These unintentional signals are sometimes referred to as TEMPEST, after the NSA and NATO specification which aims to ensure that electronic devices containing sensitive information cannot be spied upon through unintentional radio emissions, sounds or vibrations. TEMPEST can also refers to the opposite, which is spying on unsecured electronic devices by these means.
Recently the team at Fox-IT, a cybersecurity specialist company has released a paper showing how an RTL-SDR can be used as a TEMPEST attack device to help recover AES-256 encryption keys (pdf) from a distance by utilizing unintentional RF emissions. AES is an encryption standard commonly used in computing with protocols like HTTPS (e.g. with online banking) and for securing WiFi networks.
In their experiments they set up an AES implementation on an FPGA, and used a simple wire loop antenna and RTL-SDR to measure and record the RF emissions. By then doing some analysis on the recorded signal they are able to fairly easily extract the AES encryption key, thus defeating the encryption.
Further testing in an anechoic chamber showed that with a discone antenna they were able to recover the keys from up to a meter away. A directional antenna could probably reach even further distances.
In the past we’ve seen a similar attack using a Funcube dongle, which is an SDR similar to the RTL-SDR. In that attack they were able to remotely recover encryption keys from a laptop running GnuPC. Also, somewhat related is Disney’s EM Sense which uses an RTL-SDR to identify electronic devices by their RF emissions.
Aerial TV is an Android app that allows you to watch DVB-T TV with an RTL-SDR on a mobile device. We posted about Aerial TV back in April and it was available on the Google Play store back then. Unfortunately Aerial TV has recently been banned from the Google Play store as apparently the app can be used to display copyrighted material from TV. The author writes the following on a Facebook post:
Google Play has suspended Aerial TV due to “[Aerial TV] claims to provide copyrighted contents from TV channels”. According to Google apps that display live TV are of “questionable nature”. I am trying to clarify what they mean. I would like to apologize to all affected users. If you have any concerns, feel free to get in touch with Google directly.
This is quite odd and probably a mistake. But if you are looking for Aerial TV it is now available on the Amazon app store with a current 35% discount. If you bought the app on the Google Play store then to get new updates you will need to uninstall it, contact the developer for a refund, and then purchase it again on the Amazon store. More info about that is available on the Facebook page. Updates about it’s availability will always be provided on the official website at aerialtv.eu.
Amazon Echo is a smart home device which is essentially a hands free speaker that responds to voice commands in a similar way to ‘Okay Google’ and Siri does on your phone. With voice commands you can ask it to do things like play music, make a call or send a message, answer any question, control smart home devices like fans and locks and order items from Amazon.
Over on his blog Nick Sypteras has written about teaching his Amazon Echo a new ‘skill’ which allows it to automatically detect and read out what aircraft is flying outside his window, and where it is going. A skill is basically a plugin that you can code up to give your Amazon Echo new voice command functions and behavior.
The Echo skill gathers the live local ADS-B plane data via dump1090’s json output which runs on a networked Raspberry Pi with RTL-SDR dongle attached. The data is loaded into a database, which is then queried for the closest plane to the Echo’s location. Finally the program scrapes the closest flights departure and arrival data from FlightRadar24 before speaking it through the Echo’s speaker. Nicks code is freely available over on his GitHub page.
This project reminds us of a previous post where we posted about Simon Aubury’s work in creating a Raspberry Pi and RTL-SDR based aircraft camera tracking system. Simon’s system used live ADS-B data to point a camera directly at aircraft as they passed over his house.
It also reminded us of this British Airways video billboard that was popular a few years ago. The ad featured a young boy who would point directly at passing aircraft with text displaying the flight information. They used a commercial networked ADS-B device to gather live ADS-B data (internet based ADS-B data from sites like flightradar24.com has a time lag, so it is not suitable for time sensitive applications like this), and whenever a passing British Airways aircraft was detected the ad would play.
Over on his YouTube channel user Corrosive has uploaded a set of videos that show how to install and get started with an RTL-SDR or HackRF with SDR-Console V3. The video series starts from the very beginning with installing the drivers via zadig, and then goes on to show how to download, install and use SDR-Console V3.
In one of his later videos Corrosive also shows how to optimally configure the settings in SDR-Console V3 and SDR# for optimal reception and viewing.
In a newer video he also shows how he uses the HackRF as a spectrum analyzer to find his cellphone signal. Regarding this video, Corrosive wrote in to us and said the following:
For a while now I’ve been trying to find the frequency of my cell phone, looking frequencies up online and trying to find an app that would tell me my current frequency. None of these things seem to work and scanning the band manually I always came up dry because I wasn’t 100% sure where I needed to look.
Further videos on his channel also show how to receive ADSB data with an RTL-SDR and Android phone, and how he repurposed a rabbit ears antenna into a V-dipole antenna for receiving Satcom pirates.
Corrosive has done a good job putting out SDR and radio related videos over the past couple of weeks so it may be a channel to subscribe to if you are interested in this type of content.
Over on his blog Dave Venne has been documenting his attempts at using National Weather Service (NWS) broadcasts for forward scatter meteor detection with an RTL-SDR. Forward scatter meteor detection is a passive method for detecting meteors as they enter the atmosphere. When a meteor enters the atmosphere it leaves behind a trail of highly RF reflective ionized air. This ionized air can reflect far away signals from strong transmitters directly into your receiving antenna, thus detecting a meteor.
Typically signals from analog TV and broadcast FM stations are preferred as they are near the optimal frequency for reflection of the ionized trails. However, Dave lives in an area where the broadcast FM spectrum is completely saturated with signals, leaving no empty frequencies to detect meteors. Instead Dave decided to try and use NWS signals at 160 MHz. In the USA there are seven frequencies for NWS and they are physically spaced out so that normally only one transmitter can be heard. Thus tuning to a far away station should produce nothing but static unless a meteor is reflecting its signal. Dave however does note that the 160 MHz frequency is less than optimal for detection and you can expect about 14 dB less reflected signal from meteors.
So far Dave has been able to detect several ‘blips’ with his cross-dipole antenna, RTL-SDR and SDR#. He also uses the Chronolapse freeware software to perform timelapse screenshots of the SDR# waterfall, so that the waterfall can be reviewed later. Unfortunately, most of the blips appear to have been aircraft as they seem to coincide with local air activity, and exhibit a Doppler shift characteristic that is typical of aircraft. He notes that the idea may still work for others who do not live near an airport.
We note that if you are interested in detecting aircraft via passive forward scatter and their Doppler patterns, then this previous post on just that may interest you.
