In this week's Tech Minds video Matthew interviews the SDRplay team and also takes a tour of their design lab and PCB manufacturing facility. SDRplay is a manufacturer of low cost wideband software defined radios, with the cheapest starting at US$109.
The video starts with an interview with Jon Hudson from the SDRplay sales team who gives an overview of the entire SDRplay product line up, also explaining how the products have been iterated on over time. Jon also talks about the SDRuno software and team members in the company.
The next interview is with Andy Carpenter who is the head of SDRplay software development. Andy talks about SDRuno and how it came to be acquired and improved by SDRplay. They go on to discuss some recently added SDRuno features such as the plugin environment as well as the upcoming feature roadmap.
The final part of the video is a tour of the equipment used at the SDRplay design lab, and a tour of the UK based PCB manufacturing facility contracted by SDRplay.
The course appears to be intended for University teachers in order to accelerate adoption of SDR based teaching of RF courses. We're unsure if this material will be released to the general public as their signup form appears to ask for University details. They write:
Alton, England; 5th November 2020 – SDRplay Limited announces a new Radio Communications course for under-graduate teaching as part of its SDRplay Educators Programme
“Understanding Radio Communications – using SDRs” includes a rich set of teaching materials and practical exercises to help students understand the key elements of radio communications. This one semester course provides teaching materials and practical workshops that lead students from the first switch-on of a Software Defined Radio (SDR), through to signal reception, demodulation, and finally, successful communications with satellite signals.
As well as guides and set-up instructions for teachers for both the lecture and lab sessions, there are downloadable teaching materials in both PowerPoint and .pdf formats. There are video guides showing the lab activities and there’s a dedicated new forum for teachers to share experiences and to get help from the authors.
The course was created in association with academic partners Sapienza University of Rome, Department of Mechanical and Aerospace Engineering whose intention was to create a practical course that will inspire Science, Technology and Engineering students to nurture their understanding of radio communications.
The course started life as a 12-hour optional course for third-year bachelor students in Aerospace Engineering and has been broadened to make it suitable for all students that have some basic knowledge of signal theory and signal processing. It can either be run as an additional or optional “module” or adapted to be included as materials within a full year radio communications subject.
Robert Owen, University Programme specialist at Essaimage who guided the academic team, says, “I have spent 26 years in global “University Programmes” and across this time I’ve learned two fundamental principles. The first is that teaching materials must fill an essential need in the curriculum, not just be something that business thinks should be taught. And secondly, that the best teaching materials come from academics not commercial trainers. This course, Understanding Radio Communications, fulfils these principles generously, and I am proud to be associated with it!”
Key dates:19th November 2020, 1300 UTC – SDRplay and Course developers, Lorenzo Frezza and Paolo Marzioli from the Department of Mechanical and Aerospace Engineering, (DIMA), Sapienza University of Rome, will host a webinar presenting the programme and taking questions via YouTube chat.
About the SDRplay Educators Program The SDRplay Educators Program provides practical encouragement to teachers around the world so that they can use SDRplay’s SDR receivers in courses and student projects. The focus is on providing the key elements needed to teach a course: a suitable hardware platform at a reasonable price, ready access to SDRplay software, effective technical support, and excellent teaching materials that serve genuine teaching needs. The SDRplay Educators Programme is open to all members of academia, see
Over on the SDRplay blog Jon has posted about the STRATONAV experiment which makes use of the SDRplay RSP1 software defined radio. The STRATONAV experiment uses high altitude balloons to carry the RSP1 as well and a commercial portable receiver. The two receivers were configured to receive aircraft VOR navigation signals in order to test the effectiveness of VOR when used at extreme altitudes of up to 28 km. The VOR navigational data was then compared against GPS tracks, resulting in a measure of how well VOR worked at those altitudes.
VOR (aka VHF Omnidirectional Range) is a navigational beacon that is transmitted between 108 MHz and 117.95 MHz from a site usually at an airport. In the past we have posted about VOR a few times as it can also be decoded with an RTL-SDR, or used for passive doppler aircraft radar.
The results showed that VOR navigation does indeed continue to function at extreme altitudes, proving that it can be used as a back up navigation system for stratospheric platforms. They also note that VOR navigation could also be used as a primary navigation system on smaller stratospheric platforms due to its low cost and low complexity to implement.
Back in April we posted a video from Tech Minds where he showed us how to use special software combined with an SDRplay RSPdx to detect and report VDSL interference on the HF bands. VDSL or Very High Speed Digital Subscriber Line is an internet connection technology that runs over old copper phone wires allowing for a fast broadband connection. The frequencies used by VDSL are between 25 kHz to 12 MHz, and for VDSL2 up to 30 MHz. Unfortunately the frequencies used can result in high amounts of radio interference from RFI radiating from the copper phone lines which is a major problem for HF amateurs and short wave listeners.
Recently John Rogers (M0JAV) presented a talk via the UK amateur radio organization RSGB. In the talk he explains how VDSL works, why it causes RFI and how to check for VDSL RFI using an SDR and the Lelantos software. He also shows how he drove around with a magnetic loop antenna looking for VDSL RFI sources in his neighbourhood. He then goes on to call out for more volunteers in the UK to submit RFI reports to Ofcom as they responded that they won't do anything about the interference unless there are more complaints.
The RSGB EMC Committee (EMCC) has been investigating VDSL interference since 2014. As the number of installations has risen to over 30M the interference level at amateur radio stations has also increased. The majority of radio amateurs are now impacted by this problem.
In the May 2020 RadCom we outlined how to detect and estimate the level of interference. This can be done by inspection of an SDR spectrum display or by taking a recording and then using a SW package—developed by Martin Sach of the EMCC—which identifies the VDSL signature in the recording and shows how many different VDSL lines are causing the problem and what their relative strengths are.
This talk demonstrates what to look for and how to use the tools to find out if you have a problem yourselves. We hope this will help you respond to our call for action and complain to Ofcom about the level of RFI you are subjected to.
John Rogers, M0JAV Chair EMCC
RSGB Tonight @ 8 - How to check for VDSL RFI with John Rogers, M0JAV
In his latest YouTube video Tech Minds shows how to decode HF ACARS (HFDL) with an SDRplay RSPdx. Tech Minds initially explains what HFDL is, and how it is typically received via special aviation radios. He goes on to show how we can decode it from home with any HF capable SDR, and a program called PC-HFDL. Finally he explains how to set up a Google Earth file that can display the aircraft location data that is provided in some HFDL messages.
In a recent YouTube video Tech Minds shows how to decode GMDSS (Global Maritime Distress and Safety System) messages which are broadcast on MW and HF. In the video he explains the DSC (Digital Selective Calling) which allows calls to be made to individual ships, a group or all stations. He goes on to demonstrate the YADD GMDSS DSC decoder running via the HF audio piped in from SDRUno and received with an SDRPlay RSPdx.
How To Decode Maritime Distress Messages GMDSS DSC
Earlier in the month SDRplay released SDRuno V1.4 RC1. This is a beta version that amongst other changes now has the capability to run "plugins". Plugins allow developers to easily create modules that extend the functionality of the SDRUno software. For example right now there is a plugin included with V1.4 RC1 that allows users to listen to DAB audio. Up until recently plugin functionality has only been available in Airspy's SDR# software, so it's good to see SDRuno finally including this feature too.
Over on the Techminds YouTube channel Matthew has uploaded a short video where he tests out the new plugins feature. First he tests out the DAB decoder, noting that the CoreAAC codec needs to be installed first separately. Later he tests the second plugin which is an audio recorder that allows users to record audio to MP3.
Over on YouTube user Tech Minds has uploaded a video showing how you can determine if you are getting HF interference from a VDSL internet connection going to your house or neighbors. VDSL or Very High Speed Digital Subscriber Line is an internet connection technology that runs over old copper phone wires allowing for a fast broadband connection. The frequencies used by VDSL are between 25 kHz to 12 MHz, and for VDSL2 up to 30 MHz. Unfortunately the frequencies used can result in high amounts of radio interference from RFI radiating from the copper phone lines which is a major problem for HF amateurs and short wave listeners.
In his video Tech Minds uses an SDRplay RSPdx to record a short IQ file of the VDSL interference that he experiences in his home in the UK. He then opens the IQ file in a piece of software called Lelantos, which was developed by a member of the UK amateur radio organization RSGB. If a VDSL signal is present, this tool will determine various bits of information about the interference, and will give you enough information to make a complaint to OFCOM, the UK's radio communications regulator.
