Tagged: rtl2832u

Receiving Es’Hail-2 DVB-S2 on Ubuntu With LeanDVB

Yesterday we posted about a real time Windows demodulator for receiving amateur TV DVB-S/S2 on Es'Hail-2/QO-100. Recently another YouTube user "M Khanfar" also submitted a video tutorial showing how to decode Es'Hail-2 DVB-S2 on Ubuntu with an RTL-SDR and the LeanDVB decoder.

Khanfar notes that although the LeanDVB decoding method is not real time, his tests show that the LeanDVB method is able to work with a much lower SNR signal compared to the Windows demodulator. The process is to simply capture an IQ file with GQRX, then run LeanDVB on the command line with the recorded IQ file. It will create a TS file that can be played in any media player.

His receiving setup consists of an RTL-SDR, 100cm dish, modified LNB and a home made bias tee that can switch his LNB between horizontal and vertical polarization.

QO-100 DVB-S2 Decoding

A Raspberry Pi and RTL-SDR Based Boombox

Thank you to Walter P. for writing in and sharing with us his conversion of an old analog boombox into a fully functional wideband software defined radio based on an RTL-SDR dongle and upconverter.

Walters Ghettoblaster RTL-SDR Radio
Walters Boombox RTL-SDR Radio

Inside the boombox Walter stripped away the analog circuitry and replaced it with a new LCD screen, Raspberry Pi, RTL-SDR, upconverter and an audio amplifier. Four rotary switches on top of the radio are used to control the frequency, demod mode and volume, and there is also a numerical keypad which can be used to enter the frequency directly. 5V and HF antenna connectors have been added to the side, as well as an upconverter enable switch on top. Walter also added a Spyserver mode to the software, which allows you to connect to the radio over WiFi with SDR#, although he notes that using the integrated Pi WiFi module seems to introduce noise on the speakers.

If you're interested in building a similar device, Walter has provided the full Python code and installation instructions for his build.

Edit 09 May 19: It was pointed out that the word "ghettoblaster" could be considered offensive in some cultures. We have changed the word in our article to "boombox" and apologize for any unintended offence.

RaspBRadio - A Raspberry Pi and RTL-SDR Based Boombox

Windows Realtime DVB-S Demodulator for Es’Hail-2 & Amateur TV Available

Thank you to Happysat for writing in and noting that over on the Amsat-DL forums user Markro92 has uploaded a realtime Windows DVB-S demodulator with GUI. The demodulator works with the RTL-SDR, HackRF, SDRplay and PlutoSDR support is due to be added soon. Happysat notes the following: 

It can demodulate DVB-S and S2 signals with very low symbolrate on Es Hail-2 geosat on 25,9 East from the Wideband Transponder. So you do not need a modified lnb or modified satelitte stb :) Of course you can also see the amateur tv streams which people uplink theirself.

To see if there is any stream active one can visit the wideband WebSDR and above the stream the info is displayed which parameters in use (symbol rate and mode dvbs(2)) so you can adjust in the Demodulator program. Stream + Chat: https://eshail.batc.org.uk/wb/ .

The latest version of the software will always be always available at http://v.1337team.tk/dvb-s_gui_amsat.zip.

Happysat Decoding a DVB-S2 stream from Es-Hail2 with an RTL-SDR V3.
Happysat Decoding a DVB-S2 stream from Es-Hail2 with an RTL-SDR V3.

United Nations Expert Arrested in Tunisia for Using an RTL-SDR

Recently several newspapers [CNA] [France24] [Guardian] [MEM] [HuffPostMG] have reported a story about a United Nations (UN) expert being arrested in Tunisia for having an RTL-SDR dongle. Dr. Moncef Kartas is a member of a UN panel of experts investigating violations of the UN arms embargo on Libya. 

On March 26, 2019 Kartas was arrested on his arrival in Tunisia on suspicion of spying for "unnamed foreign parties", and one of the key arguments being used against him is that he was in possession of and had used an RTL-SDR dongle. In the France24 article, they explain that he was using the RTL-SDR as part of his investigation for monitoring air traffic to Libya in an attempt to link flights against violations of the arms embargo. 

As Kartas' business in Tunisia was to present his findings on the arms embargo violations, other experts believe that the arrest is politically motivated, and that ownership of the RTL-SDR for espionage is simply being used as an excuse. However, while the investigation continues Kartas remains in jail, and in Tunisia a charge of espionage could be punishable by death. As Kartas holds UN diplomatic immunity, and as Tunisia is a member of the UN, the arrest and detainment is seen as illegal.

We hope that Kartas is safe and will be released soon. If you want to keep an eye on his story, there is a Twitter account called "Free Moncef Kartas" @FreeMoncefK that appears to be posting news articles and tweets about his arrest.

Human Rights Watch Denounces the arrest of Moncef Kartas
Human Rights Watch Denounces the arrest of Moncef Kartas [Photo Source]

KerberosSDR Direction Finding with Android App Demo and Tutorial

Over on our YouTube channel we've uploaded a short video that gives a tutorial and demo of the KerberosSDR being used as an RF direction finding system in a car. If you weren't aware, KerberosSDR is our recently released 4x Coherent RTL-SDR which can be used for tasks such as direction finding and passive radar. KerberosSDR was successfully crowdfunded over on Indiegogo, and we have recently completed shipments to all backers. Currently we are taking discounted pre-orders for a second production batch on Indiegogo.

In the video we use a Raspberry Pi 3 B+ running the KerberosSDR image as the computing hardware. The Pi 3 is connected to a high capacity battery pack. It is important to use a high quality battery pack that can output 3A continuously as this is required for the Raspberry Pi 3 B+ to run without  throttling. The battery pack we used has multiple outputs so we also power the KerberosSDR with it.

Once powered up we connect to the KerberosPi WiFi hotspot, and then browse to the web interface page. We then tune the KerberosSDR to a TETRA signal at 858 MHz, perform sample and phase calibration, set the decimation and FIR filtering, and then enable the direction finding algorithm. At this point we enter the Android app and begin direction finding and logging our data.

After driving for a few minutes we stop and check the logfile and find that the majority of the bearing lines point in one direction. With this info, a drive in the direction of the bearing points to gather more data is performed. Once additional data was gathered we open the log file up again, and see where all the bearing lines cross. Where they cross indicates the location of the 858 MHz transmitter. The heatmap data also gives us a second confirmation that the transmitter is located where we think.

NOTE: Some of the features shown in the video like the heatmap, confidence settings and plot length settings are not yet released in the current version of the app. They will be released next week.

Full instruction on using the KerberosSDR are available at rtl-sdr.com/ksdr.

KerberosSDR Direction Finding With Android App Demo and Tutorial

Using an RTL-SDR and OpenCV To Create an EMI Heatmap of Circuit Boards

Over on YouTube and his blog user Charles Grassin has uploaded a short video and blog post showing how he's using an RTL-SDR EMI (electromagnetic interference) probe and OpenCV to create a visual EMI heatmap.

Earlier this month we posted about Dmitris' experiments in which he was able to create a home made EMI/EMC probe out of a loop of semi-rigid coax and an RTL-SDR V3. This type of probe is useful for determining what components or areas on a circuit board are emitting electromagnetic interference. EMI testing for PCBs may be critical for passing compliance tests.

Charles' project takes the RTL-SDR EMI probe idea a step further by combining it with OpenCV. OpenCV is an open source library of code for computer vision applications. With the EMI data generated by the RTL-SDR EMI probe, and a camera pointed at a PCB, Charles is able to overlay a heatmap on top of the visual image which reveals the EMI hot spots on a PCB.

The video below shows the EMI heatmap of an Arduino PCB being mapped out. His blog post shows some other examples like a keyboard and a hairpin RF filter. The code he's created is open source and available on his EMI_Mapper GitHub page.

EMI mapping (OpenCV and RTL-SDR)

Scanner School Podcast Talks SDR Topics with Signals Everywhere Host

Recently Scanner School released episode 70 of their podcast, and on this episode they talk about various SDR topics with Corrosive from the Signals Everywhere YouTube channel. If you follow out blog, you'll know that Corrosive is a YouTuber that is consistently putting out high quality YouTube videos on a range of SDR and other radio related topics.

Scanner School is an online workshop that aims to help you get setup with an RTL-SDR based DMR/NXDN/P25 trunking system in four classes. They also have a weekly podcast. The description of this weeks podcast with Corrosive reads:

Corrosive has been working on his YouTube channel for about 4 years, and has a ton of videos on the SDR topic. If there is something that I am looking a trying when it comes to SDR, the first place I look is on Corrosive's channel.

Today we talk about some advanced SDR topics, both for receiving and transmitting.

While we talk about the more advanced topics of SDR today, I know we all have to start somewhere. If you are looking for online training to help you get started with SDR, check out our new Intro to SDR Workshop. This course will guide you though purchasing an excellent and affordable SDR to get started with.

Additionally, we will turn this SDR into a DMR, P25, and NXDN trunked receiver that can do more than your expensive scanner.


HackSpace Magazine Discusses SatNOGS, Cubesats and More

HackSpace is a monthly magazine dedicated to modern maker projects. This month issue 18 was released and it focuses on space based projects. The HackSpace Magazine is available for free online in PDF form, and physical copies can also be purchased.  There are several interesting articles but one in particular shows us how to set up a SatNOGS ground station with a Raspberry Pi 3, RTL-SDR and a satellite antenna such as a turnstile. 

A problem with low cost satellites like cubesats is that it is difficult to monitor them as data can only be collected when they are passing over a ground station. So in areas with no ground stations data is simply lost. SatNOGS is an open source project that aims to make it easy for volunteers to build and run RF ground stations that automatically monitor satellite data, and upload that data to the internet for public access. SatNOGS ground stations typically use RTL-SDR dongles as the radio.

A related article in the magazine also discusses cubesats, giving an overview of some previous cubesat launches and what sort of payloads are available. A third article under the space topic discusses the Libre Space Foundation which is the team behind the SatNOGS and various other space based projects that aim to democratize space. Readers may also be interested in the articles showing how to build an ISS countdown timer and how to build a Slim Jim antenna.

HackSpace Magazine SatNOGS Article
HackSpace Magazine SatNOGS Article (Excerpt)