Category: Other

SignalsEverywhere Podcast: Is Software Defined Radio Illegal?

Corrosive from the SignalsEverywhere YouTube channel has released a new episode of his podcast, this time discussing the topic "Is Software Defined Radio Illegal?". Recently we posted about the unfortunate arrest of a UN investigator in Tunisia. Reports from news agencies seem to indicate that a major factor in his arrest was his use of an RTL-SDR dongle for monitoring air traffic as part of his investigation on Libya arms embargo violations. Although it is suspected that other political motivations are at play.

In his podcast Corrosive tries to open a discussion on whether software defined radio (SDR) is illegal, since SDR receivers have the possibility to be able to receive, demodulate and decode almost any signal. He first focuses on mostly American FCC laws regarding scanners, but similar laws are likely to be in place throughout most of the western world. Later in the podcast he discusses transmit capable SDRs and how these are more likely to come to the attention of politicians.

Online Course: Software Defined Radio From 0 to 1

Back in March we posted about Qasim Chaudhari and his recently released book titled "Wireless Communications From the Ground Up - An SDR Perspective". The book covers advanced University level wireless topics, but he noted how he's attempted to keep the math at school complexity (although for most people we'd say it's still more at undergraduate Engineering school complexity).

Since the last post Qasim has received a lot of feedback from radio amateurs asking for a much simpler introduction to DSP concepts, without the use of University level math. Recently Qasim wrote in and noted how he's now created a set of online lectures that is intended for either professionals who want an overview of physical layer algorithms, or radio hobbyists and general technical persons who want to expand their knowledge.

The course costs US$37 (currently discounted by 20% to $29.50 via this coupon link) and has a sampling of free videos for you to watch.

A sample slide from Qasim's Lectures
A sample slide from Qasim's Lectures

Elektor SDR Hands-on Book + Arduino Shield HF SDR

Elektor is a popular electronics magazine and hobbyist kit store. Recently they have published a book titled "SDR Hands-on Book" written by Burkhard Kainka. The book is intended as a companion to their Arduino SDR shield kit, which is a low cost module that allows you to turn an Arduino into a 150 kHz to 30 MHz capable SDR. It is based on the G8JCFSDR, which is an RF front end downconverter that allows a PC soundcard to be used as an SDR analog to digital converter.

Kainka's book goes over introductory topics such as shortwave reception, explains signal to noise ratio and interference, different types of antennas, software, digital modes, SDR measurements, receiving and finally WSPR and QRP transmission. If you're interested Jan Buiting also recently reviewed the book on the Elektor website.

Elektor are currently running a promotion and are selling the book + Arduino shield for a reduced price of €49.90.

The Elektor Arduino Shield HF SDR Kit.
The Elektor Arduino Shield HF SDR Kit.

The 2019 New England Workshop for SDR

The New England Workshop on Software Defined Radio (NEWSDR) is a yearly conference that hosts multiple SDR related talks. Previously we posted a selection of our favorite 2018 talks which involved topics such as remote sensing of space with SDR, wireless deep learning and multi-objective SDR optimization.

This years NEWSDR event will been held on Jun 13 and 14 at the University of Massachusetts in Boston. They are currently offering pre-registration for free, and are looking for poster presentations.

This year is the 9th iteration of NEWSDR and it will be held at the University of Massachusetts Boston campus on June 13 and 14. Registration is free and we are also accepting submissions for poster presentations and elevator pitches. The event is an excellent networking opportunity and includes technical presentations as well as demonstrations from industry sponsors (Ettus/NI, MathWorks, Analog Devices, and MediaTek).

NEWSDR 2019 Poster
NEWSDR 2019 Poster

SignalsEverywhere Podcast EP2: Common SDR Mistakes and How to Resolve Them

Corrosive from the SignalsEverywhere YouTube channel has recently released episode two of his new podcast. This episode is titled "Common SDR Mistakes and How to Resolve Them". In the podcast Corrosive discusses some tips like how to ensure that the gain on your SDR is set correctly, how to set the sample rate, how to optimize the waterfall display, and what antennas to use. Later he goes on to talk about our RTL-SDR Blog V3 dongles, and discusses some posts from our blog.

Creating an EMC Probe using an RTL-SDR and Semi-Rigid Coax

Thank you to Dimitris for submitting his article on creating an RTL-SDR based EMC probe. An EMC probe is a device that can be used to detect electromagnetic interference leaking from areas on electronic devices. For example an electronic PCB might have problems with RF leaking into other components. With the probe you could determine where the leak is coming from.

To create the probe he uses a 30cm semi-rigid coax cable and an RTL-SDR dongle. The semi-rigid coax is cut in half, the center conductor stripped back, then looped around on itself and soldered to the shield. Dave from EEVBlog did a video on this previously which is what inspired Dimitris. The next steps are simply to connect the probe to an RTL-SDR, put it into direct sampling mode and probe around for signals. Note that an RTL-SDR with direct sampling like our V3 model, or an RTL-SDR with upconverter is required to receive signals below 24 MHz.

His results show that he was able to successfully probe an OCXO oscillator, by seeing the 10 MHz signal in SDR#. The rest of his post goes on to discuss the limitations of this method, and compares it against professional EMC probes available on the market.

RTL-SDR Based EMC Probe
RTL-SDR Based EMC Probe

Reaching Across Europe with a Raspberry Pi Zero and WsprryPi

Over on YouTube user Techminds has uploaded a video that shows how he is using a Raspberry Pi Zero to transmit WSPR. To do this he uses the WsprryPi software which allows you to transmit WSPR by connecting an antenna directly to a GPIO pin on the Pi Zero. With this no extra hardware is required, although a filter is highly recommended to reduce spurious emissions from harmonics.

In his test Tech Minds directly connected the Pi Zero to an unun and HF wire antenna and ran WsprryPi. His results showed that even with the tiny 10mW output power of the Pi Zero's GPIO port his WSPR messages were able to reach several receivers halfway across Europe, and even to Iceland and Morocco from his home in the UK.

WSPR is an amateur radio digital HF mode designed to be decodable even if the signal is transmitted with very low power and is very weak. It can be used to help determine HF radio propagation conditions as WSPR reception reports are typically automatically uploaded to wsprnet.

WSPR - Weak Signal Propagation Reporter - From A Pi Zero ?

GNU Radio Conference 2019: Registration Open + Call For Papers

GNU Radio Conference is a yearly conference based around the GNU Radio project and the surrounding community. GNU Radio is an open source digital signal processing (DSP) toolkit which is often used to implement decoders, demodulators and various other SDR algorithms.

GRCon is the annual conference for the GNU Radio project & community, and has established itself as one of the premier industry events for Software Radio. It is a week-long conference that includes high-quality technical content and valuable networking opportunities. GRCon is a venue that highlights design, implementation, and theory that has been practically applied in a useful way. GRCon attendees come from a large variety of backgrounds, including industry, academia, government, and hobbyists.

The 2019 GNU Radio Conference will be held on September 16-20 at the Marriot at the Space & Rocket Center in Huntsville, Alabama.

Registration and a call for papers and posters is currently open, see gnuradio.org/grcon/grcon19.