Over on hackster.io we've seen a story about how maker Jon Dawson designed a self-contained software-defined radio based on the Raspberry Pi Pico that can receive 0 - 30 MHz, with up to 250 kHz of bandwidth. The Raspberry Pi Pico is a microcontroller board based on the Raspberry Pi Foundation's own RP2040 chip.
The Pi Pico Rx's front end consists of a Tayloe Quadrature Sampling Detector (QSD) mixer which makes use of the PIO (Programmable Input/Output) feature on the RP2040. The circuit also has an encoder knob for tuning and a small OLED screen.
Jon had originally created the Pi Pico Rx on a custom PCB, however, his latest work brings the cost down by showing that it can just as easily be implemented on a breadboard with through-hole components.
The full writeup can be found on Jon's blog "101 Things", as can the open source firmware. He has also uploaded a YouTube video explaining and demonstrating the project which we've embedded below.
The LibreSDR is a relatively new software defined radio on the market. It is based on the AD9363 radio transceiver chip and an AMD XC7Z020 FPGA, and appears to be an upgraded/modified Chinese clone of the PlutoSDR. It can be found on marketplace sites like Banggood for US$319.99. (The Tech Minds YouTube description box also notes coupon code BG91c241, Exp:8/31, which brings it down to US$$259.99)
In his video, Matt from the Tech Minds YouTube channel introduces the LibreSDR / ZynqSDR, and explains how to set up the LibreSDR firmware, which is an unofficial port of the PlutoSDR firmware.
He then tested the SDR with SDR++ on Windows for receiving the air-band and found that it worked well, except that it only worked over USB, and did not work with the ethernet connection. Next, he tries SDR-Console V3, and finds that he is able to connect to the LibreSDR via ethernet with this software. Matt goes on to test his QO-100 setup, replacing his PlutoSDR with the LibreSDR, noting that the VCTXO in the LibreSDR works great to prevent any signal drift.
Finally, Matt tests transmission of DATV with the LibreSDR, but finds an issue with a center spike causing issues with decoding. He notes that the center spike does not occur with his PlutoSDR.
LibreSDR / ZynqSDR Software Defined Radio - 70 MHz to 6 GHz
The latest August edition of the RadioWorld Magazine has included an article by James Careless about the use of software defined radios for shortwave radio listening. RadioWorld is a magazine targeted towards radio broadcast owners, managers and engineers all over the world. The article explores SDRplay and RTL-SDR Blog V4 units from the perspective of a shortwave listener new to software defined radios, comparing them to his high-end Sangean ATS-909X2 shortwave digital receiver.
Over on her YouTube channel SignalsEverywhere, Sarah has uploaded a new video showing how to use a program called 'hacktv-gui' to transmit analog TV signals using a HackRF software defined radio. Analog TV standards such as PAL and NTSC have been phased out in most of the world in favor of digital TV standards instead. However, transmitting these yourself can be a fun experiment that may help breathe life into old television sets.
In the video Sarah explains how to use the hacktv-gui and hacktv software, and how to create a video transmission. She mentions how hacktv also supports the use of a FL2K device, which is a cheap VGA adapter that can be used to transmit signals.
HackTV | Analog Television Transmission with a HackRF SDR
The RTL-SDR hardware began its life as a DVB-T TV receiver USB stick, but these days it is rarely used for this purpose. However, in countries where DVB-T hasn't been upgraded to DVB-T2 it is still possible to use the RTL-SDR for TV reception.
Recently, RADIOTO bg from DXing.org wrote in and wanted to share with us his video showing how to use the RTL-SDR V3 for DVB-T reception in OpenPli Enigma2. OpenPli is an open-source Linux distribution for TV set-top boxes and Enigma2 is the TV application it runs.
RADIOTO's video shows a step-by-step guide to setting up the RTL-SDR in OpenPli. The procedure is relatively simple, just requiring the user to select the correct driver for the RTL-SDR via the set-top menu.
How to make rtl-sdr v.3 as a additional DVB-T tuner in enigma2 receiver (OpenPli) Manual
Recently on the Tech Minds YouTube channel, Matt uploaded a video explaining how to set up and use the Radioberry HF SDR Transceiver Pi Hat. The Radioberry is an HF SDR transceiver based on the AD9866 chip. It has an operating frequency between 0 - 30 MHz, a 12-bit ADC, a maximum bandwidth of up to 384 kHz, and one RX and one TX channel. It is designed as a 'Pi hat' which means that it needs to be connected and sit on top of a Raspberry Pi single-board computer.
In his video Matt shows how to set up the Radioberry Raspberry Pi software. The process begins with installing the Raspbian OS, logging into SSH, and running the Radioberry installation script. He then shows how to connect to the Radioberry over a local network using SDR-Console V3. Later he shows how to install the pihpsdr software which gives the Radioberry a desktop control app that can be used with a LCD screen connected to the Raspberry Pi.
Matt goes on to show how he was also able to use the Radioberry TX function to make WSPR contacts across Europe from with his home location in the UK, despite its very low 150 mW output power.
The Beginners Guide To The Radioberry HF SDR Transceiver Pi Hat
Over on his YouTube channel, Simon has uploaded a video showing how while on holiday he was able to explore the various HD Radio stations available around the USA.
If you are in the USA, you might recognize HD Radio (aka NRSC-5) signals as the rectangular looking bars on the frequency spectrum that surround common broadcast FM radio signals. These signals only exist in the USA and they carry digital audio data which can be received by special HD Radio receivers. Earlier in 2017 a breakthrough in HD Radio decoding for SDRs like the RTL-SDR was achieved by Theori when he was able to piece together a full HD Radio software audio decoder that works in real-time. Nowadays you can use software like HDFM - HD Radio GUI to easily receive HD Radio with an RTL-SDR.
In his video Simon shows the various HD Radio signals he found while on holiday, and also shows some of their secondary features, including traffic data, and weather radar maps. Interestingly he also spots HD Radio in the AM bands, but finds his signal is not strong enough to decode.
The rest of the video explores other signals he finds such as a studio link, and TV audio signals.
I Found Some CRAZY Radio Technology while Traveling!
This post is about the KrakenSDR, one of our products from our sister company KrakenRF. If you weren't already aware, KrakenSDR is our 5-channel coherent radio based on RTL-SDRs, and it can be used for applications like radio direction finding. It can be purchased on Crowd Supply.
In this update we'd like to share some of the KrakenSDR projects we've been working on, as well as various projects we've seen from our customers.
Kraken Pro Cloud Online Mapper Updates
Recently we've been working hard at improving the 'Kraken Pro Cloud' online mapper service at map.krakenrf.com. If you were unaware, this service is an online mapping application that can be used together with one or more KrakenSDRs to display their generated bearings on a map. This is useful if you have multiple KrakenSDRs at fixed sites spread out over a wide area, as it allows you to instantly triangulate. The features include:
Multiple Kraken's displaying on a single map
Display a Heatmap just like the Android App
Ability to remote control the Kraken's individually, or all together from a single interface
Ability to share your Kraken with other users
Display log files collected from the Android App or Kraken Web GUI
Recently we've added multiple new features and improved several points:
Ability to plot multi-VFO (multi frequency) data coming from a KrakenSDR
Ability to put Kraken's into groups
Improved heatmap calculation and rendering speed
Fixed a memory leak that caused the mapper to crash after several hours
Improved the history feature (see further below)
Improved the interface
We'd like to especially highlight the improvements to the history feature. The history feature allows you to look back in time and see what the bearings and heatmap at that time looked like. This is useful if you are tracking something, but don't know exactly when the transmissions occur, or are tracking a moving object, and want to be able to review data at a later time.
Currently, we are supporting up to a week of free history, but this may change depending on how much history affects server load. For full disclosure, we eventually plan on making longer history recording available, but this will likely be a paid subscription feature. The timeframe of free history provided may change in the future too.
We also added the ability to play back history at faster speeds, kind of like a timelapse. To do this the heatmaps for each interval need to be precomputed first so that the playback is smooth, and so a 'precompute' button has been added.
We also want to note again that Kraken Pro Cloud is currently in beta, and there may still be some bugs. We also do not guarantee any uptime or privacy so please do not use the service for mission critical tasks. If you encounter bugs, please report them on our forums at https://forum.krakenrf.com, or via email to [email protected].
The gif animation below shows heatmap playback at 4x speed while the KrakenSDR was tracking the bearing towards a weather balloon.
Kraken Pro Cloud Mapper History Playback
KrakenSDR Core Updates
Since the last update we have made various bug fixes and a few minor changes to the core software. We highlight some changes below:
Our images have been updated to include SignalMedic's TAK server. (More on this in a section below)
(Beta feature) Added the ability to demodulate narrowband FM to audio files. This is in beta as the audio files don't come out particularly clean sounding, but it may be useful for some.
With the release of the Raspberry Pi 5, we have now also added a Raspberry Pi 5 ready-to-use image as well. The Raspberry Pi 5 runs the KrakenSDR software very smoothly and makes the GUI very responsive. Performance is similar to the Orange Pi 5. If are are new and choosing a platform to run the KrakenSDR on, we would highly recommend the Raspberry Pi 5 now.
Recently we have been working on getting an iOS version of the KrakenSDR app out. The app is close to completing development and should be out within about a month. Once released we will update our Wiki with links to the app, or you can simply search on the iOS app store for 'KrakenSDR'
KrakenSDR Crowdsupply Conference Workshop
One of the members of our team, Syed, recently ran a workshop on KrakenSDR. The workshop had attendees put together a KrakenSDR set on a large pizza pan and had teams go out into a local park to find a hand held radio transmitter. Photos of the day can be found here.
KrakenSDR Workshop at the Crowd Supply Conference
Highlights from Customers
KrakenSDR YouTube Tutorial from Skyler F
Over on YouTube user 'Skyler F' has uploaded a great video that demonstrates and shows how to set up KrakenSDR. In the video he demonstrates him finding some cellular phone towers.
Kraken Radio Direction Finding Unit Setup Tutorial and Demo
KrakenSDR Talk by KO4CEQ
We've also seen a great talk by KO4CEQ about KrakenSDR which has been uploaded to YouTube. In the talk he discusses KrakenSDR and shows his very neat car based setup.
PCARS March 2024 Mobile DF with KrakenSDR
Elektor Review of the KrakenSDR
Online store and magazine Elektor has uploaded to their blog a great review of the KrakenSDR. In the review they explain the KrakenSDR specs, and how it can be used as a regular SDR, and then go out to show how they created an antenna array and used the DoA software.
Elektor's Review of the KrakenSDR
Signal Medi's TAK Server
Thanks to 'SignalMedic' who had coded up a TAK server for KrakenSDR. TAK (Tactical Assault Kit) is software used by the military and other organizations for visualizing geospatial information such as enemy and friendly positions. Civilian versions of TAK also exist, such as ATAK for Android.
The TAK server allows for a KrakenSDR cursor to appear on a TAK map. TAK only allows for a single bearing line to show, so it's not as effective as our own mapping app, but this may be useful for customers who are only using TAK.
SignalMedic has made two implementations. One based on NodeRED, and the other based on Python. As mentioned previously, our image files now include the Python TAK server.
KrakenSDR TAK Server by SignalMedic
Aaron (aka cemaxcuter, aka creator of DragonOS) has also uploaded a video showing the TAK server in action.
WarDragon KrakenSDR to TAK Server w/ Node-RED (KrakenSDR)
Adrian's 3D Printed Antenna Spacer Arm
In the past we've highlighted Adrian's excellent 3D printed antenna spacer. The files for the 3D printed antenna spacer are available on Thingiverse.
Adrian has recently created a modified version of the arm that is significantly longer and should be able to cover 150 MHz to 1766 MHz. He also notes that he's updated the original arm to include files for laser cutting.
Dbvanhorn 3D Printed Antenna Spacer
We've also seen another 3D printed antenna spacer uploaded to Thingiverse. This file is based on OpenSCAD and allows you to customize the length to be printed.
