Over on YouTube Christopher Bridges has uploaded a video showing him using a PlutoSDR and a GNU Radio program to transmit a DVB-S signal, which is then received with an RTL-SDR. DVB-S is a digital video broadcasting standard designed for satellite transmissions and digital amateur television video (DATV) also uses DVB-S in the 1.2 GHz amateur band. In this example the PlutoSDR transmits at 1.28 GHz.
Chris uses the rtl_sdr command line software to receive the raw IQ data at 1 MSPS, and then uses the leandvb software to decode the raw IQ file directly into a video file.
If you’re interested in TXing DVB-S/DATV but don’t have a transmit capable SDR, then we note that even a Raspberry Pi just by itself can be used to transmit it with rpidatv.
Linux gnuradio QPSK DVBS PlutoSDR + rtl MacBook leansdr
Thanks to Marcin Jakubowski for submitting news about his new software tool called iqToSharp which is a simple tool that allows you to convert rtl_sdr IQ files into the SDR# IQ format. The rtl_sdr command line tool records raw IQ files but by default they are not compatible with the format used by SDR# so a conversion is required.
This is useful as for example you could set a command line script to record an entire band for a few hours on a portable Linux device like a Raspberry Pi, and then use the converter to listen to the file on SDRSharp at a later time. Recording the raw IQ file allows you to record all signals within the entire bandwidth at full quality.
Note that IQ files can become very large so for archiving compressing them with FLAC can be useful. You might also be interested in the SDR# FilePlayer plugin which allows you to easily skip back and forth in time through a recorded IQ file.
Thanks to Doug Ward (@dsward) for letting us know about his new RTL-SDR compatible MacOS based app called LocalRadio. LocalRadio is an open source web browser based app that connects to a MacOS server running an RTL-SDR. The software allows you to listen in on any frequency supported by the RTL-SDR in AM or FM modes, and audio is capable of being streamed to multiple devices via a built the LAME MP3 encoder, EZStream and Icecast server. It does not provide an FFT or waterfall display however.
The software introduction reads:
LocalRadio is an experimental, GPL-2 licensed open-source application for listening to “software defined radio” on your Mac and mobile devices. With an inexpensive RTL-SDR device plugged into the Mac’s USB port, LocalRadio provides a casual listening experience for your favorite local FM broadcasts, free music, news, sports, weather, public safety and aviation scanner monitoring, and other radio sources.
LocalRadio’s easy-to-use web interface allows the radio to be shared from a Mac to iPhones, iPads, Android devices, and other PCs on your home network. No additional software or hardware is required for sharing with mobile devices, simply use the built-in mobile web browser to connect to LocalRadio and tune to your favorite stations. You can also listen to LocalRadio audio on your Apple TV and other AirPlay-compatible devices.
LocalRadio does not provide features like FFT waterfalls, panadapters, or signal recording that are found on other SDR software. For those features, GQRX for Mac is highly recommended. GQRX is a good way to discover radio frequencies that can be used with LocalRadio.
LocalRadio is intended for use as in-home entertainment, using a local area network with a private IP address. It has not been tested with a public IP address, particularly for security testing, therefore it is not recommended for that purpose. For simply listening to LocalRadio on the Mac with the RTL-SDR device plugged in, no network is required at all.
Since September 2016 we’ve been slowly hearing news about the PantronX Titus II portable SDR system, but as of yet nothing seems to have eventuated. The Titus II is essentially an Android touch screen tablet running their custom software, a set of speakers, an antenna and an SDR chip with 100 kHz to 2 GHz tuning range all in one portable system that has been estimated by them to retail for less than $100 USD. The main goal with the system is to provide low cost receivers for digital broadcast standards like DRM, DAB and DAB+ to try and boost their popularity.
Titus II receiver features include:
DRM in the AM bands (MW, SW, LW) and VHF bands (FM-band, VHF band-I, VHF band-III) with latest xHE-AAC audio codec.
DAB Classic/DAB+ (VHF band-III).
FM stereo with RDS (Service Signaling).
AM with AMSS (AM Signaling Service).
Integrated service list management and service selection.
DRM/DAB Data Apps: Text Messages, Dynamic Label/DL+, Journaline, (Categorized) Slideshow, EPG, Transparent File Transmission (e.g., for educational services), etc.
Remote Radio Hotspot: Built-in WiFi hotspot feature, which allows any mobile device with an HTML5 web browser to connect to the Titus II via Wi-Fi, select radio services, listening to aud (HTML5 audio streaming) and accessing all the DRM/DAB data apps.
Recording feature and Archiving interface to select existing recordings for playback.
Titus SDR, a division of PantronX, says the Titus II multi-standard digital radio receiver is ready for production.
The consumer software-defined radio digital receiver platform, which is the result of collaboration between Titus SDR/Patron X, Jasmin-Infotech, TWR, and Fraunhofer IIS, supports multi-standard radio reception, including DRM, DAB and DAB+ and core data applications. The system is based on a custom Android tablet platform, featuring multipoint touch, WiFi/Bluetooth and stereo sound.
Titus II units will be available as a stand-alone product from Titus SDR as well as from selected OEMs. Titus SDR explains that as a module, Titus II can serve as a full-featured basis for third-party product development, adding that PantronX provided the platform and RF expertise, while Fraunhofer IIS enabled the digital and analog radio features.
With latest xHE-AAC audio codec, Titus II supports DRM in the AM and VHF bands; DAB/DAB+; FM stereo with RDS; AM with AMSS; integrated service list management and service selection; DRM/DAB data apps; text messages and Journaline.
No news yet on exact release dates, but if you are interested you can sign up to their pre-order notification list at titusradio.com.
The Titus II
From YouTube we’ve also found a short video of them demonstrating the Titus II from DBS2017 back in March. Another video showing the interface up close can be seen here.
Thank you to Adrian for submitting his video about using the Android App called QRadioLink and an RTL-SDR to decode digital amateur radio voice transmissions. Adrian writes that in the video the RTL-SDR connects to the Android phone with a USB OTG cable and uses a sample rate of 1 MSPS. He also writes the following about QRadioLink:
QRadioLink is a building platform which allows experimenting with VHF-UHF SDR transceivers using different modulation schemes for digital data transmissions. So far digital voice and text transmission is supported, using either a narrow band modem and Codec2 or a high bandwidth modem and Opus. Supported hardware includes the RTL-SDR, Ettus USRP, HackRF, BladeRF and in general all devices supported by libgnuradio-osmosdr.
QRadioLink running on Android (Debian chroot) with RTL-SDR
Over on YouTube user Fuzz has uploaded a video showing his solar powered NOAA weather satellite receiver.
The system is based on a Raspberry Pi connected to an RTL-SDR.com dongle. The front-end input of the RTL-SDR dongle consists of an LNA and FM reject filter, and this is all connected up to a QFH antenna in his front yard. The electronics are completely solar powered, with the solar system consisting of solar panel, solar controller and four 12v batteries used for energy storage. A 12V to 5V step down converter is used to power the Raspberry Pi, with the 12V LNA being powered directly by the batteries. The system is able to be accessed remotely via the Raspberry Pi’s WiFi connection.
Over on Twitter @lambdaprog and @mm6dos, developers of SDR# and Airspy SDR products have tweeted videos showing off an Android watch being used as an SDR interface. They use a prototype of their upcoming Airspy HF+ SDR, their SpyServer streaming software and an Android watch. The Android watch receives the streaming FFT and audio data from a server running the SpyServer and Airspy HF+.
They write that this new SpyServer client is mainly for phones and tablets and is efficient enough to run on a watch. It appears that this lightweight version of the SpyServer sends compressed FFT and audio instead of a slice of the IQ data like the current SpyServer, making it very light on the client side CPU and network usage.
If you’re interested in the Airspy HF+ we have an initial review available here.
In 2015, artist Ai Weiwei was bugged in his home, presumably by government actors. This situation raised our awareness on the lack of research in our community about operating and detecting spying microphones. Our biggest concern was that most of the knowledge came from fictional movies. Therefore, we performed a deep study on the state-of-the-art of microphone bugs, their characteristics, features and pitfalls. It included real life experiments trying to bug ourselves and trying to detect the hidden mics. Given the lack of open detection tools, we developed a free software SDR-based program, called Salamandra, to detect an locate hidden microphones in a room. After more than 120 experiments we concluded that placing mics correctly and listening is not an easy task, but it has a huge payoff when it works. Also, most mics can be detected easily with the correct tools (with some exceptions on GSM mics). In our experiments the average time to locate the mics in a room was 15 minutes. Locating mics is the novel feature of Salamandra, which is released to the public with this work. We hope that our study raises awareness on the possibility of being bugged by a powerful actor and the countermeasure tools available for our protection.
The paper first outlines the history of microphone bugs and tries to dispel some of the myths about them which originate from movies and other fictional sources. They then perform a survery of the current state-of-the-art microphone bugging techniques, and later go on to discuss the development of Salamandra and some experiments that they performed with it.
In their experiments they show that the Salamandra software and RTL-SDR is able to outperform a commercial bug detector. They also performed several real world simulations where one researcher would hide a bug in a room, and then another would have to use Salamandra to determine if a bug was present, and then locate it using the location feature of Salamandra. They concluded that Salamandra was a very useful tool as they were able to detect the location of the bugs in under 40 minutes in 4/5 tests.
An example waterfall of a microphone bug transmitting and being received with an RTL-SDRLocation of a hidden bug in one of their tests.
