Category: Applications

Locating an Intermittent Interferer with a KrakenSDR

Over on YouTube Thomas Brinkoetter has uploaded a video demonstrating his experience with the KrakenSDR, and how he used it to find an intermittent interferer that he set up for a test. The video was prepared to support the RF Interference and Mitigation class at the IWCE trade show Las Vegas March 17 and 18th 2025.

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 currently be purchased either directly from our krakenrf.com website, or from Crowd Supply or Mouser.

The test involved his wife keying up a repeater for one second out of every 15 seconds. In the video Thomas was able to successfully locate the transmitter with an antenna array and KrakenSDR mounted in his vehicle.

Locating an intermittent interferrer with the Kraken SDR

A Detailed Guide to Setting up RTL1090 for ADS-B Decoding

RTL1090 is a popular ADS-B decoder program that works with RTL-SDR dongles. With it, you can receive ADS-B signals from aircraft, decode them, and then pass that data to a mapping program to plot aircraft positions on a map.

Recently, RTL-SDR.COM reader Frank wrote in and wanted to share with us a detailed guide he's written on the process of setting up RTL1090. The guide starts by showing how to set up the RTL-SDR dongle by installing the WinUSB drivers via Zadig. It goes on to show how to download, unzip, and run RTL1090. Guides for RTL1090 V1, V2, and RTL1090 Scope are shown separately.

RTL1090 Scope
RTL1090 Scope

Sn0ren Tests out the KrakenSDR

Over on his YouTube channel, sn0ren has uploaded a video showing his experience with the KrakenSDR. 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 currently be purchased from Crowd Supply or Mouser.

In the video, sn0ren explains radio direction finding in general and then goes on to show how to set up and use KrakenSDR. Sn0ren writes:

Wireless communication is inherently anonymous. There is no way of knowing who transmitted a signal if they do not identify. And there is no way of knowing where that signal is transmitted from. Unless you actively track it down. KrakenSDR is a radio direction finding device that uses an array of antennas and synchronised receivers to track down the position of a given radio transmission and lead you directly to its physical location.

Track Down Radio Transmitters / KrakenSDR

Saveitforparts: Receiving the Bitcoin Blockchain from the Blockstream Satellite Network

Over on his YouTube channel 'saveitforparts' has uploaded a new video showing how he was able to download the Bitcoin blockchain via the Blockstream Satellite network. The Blockstream satellite network allows people in remote communities without an internet connection to receive the entire Bitcoin blockchain via satellite. With the blockchain Bitcoin users can confirm if a payment to them has been made.

After several failed attempts, he was finally able to receive and decode the signal using a fold-out satellite dish with an LNB and an RTL-SDR Blog V4. He also attempts to use the encrypted messaging feature on the blockstream satellites. However, while the message appears to have been received, he was unable to actually view the message due to an error. He writes:

A while back I heard about the Blockstream Satellite network, which claims to offer real-time streaming of the Bitcoin blockchain to anyone with a satellite dish. While I still don't understand cryptocurrency, I thought the satellite part of this sounded interesting!

It took a while to locate the correct satellite (Galaxy 18 in North America), and to get the software working, but eventually I was able to start downloading the blockchain file. What to do with it next, I have no idea!

I also tried sending messages through the satellite, but unfortunately I wasn't able to decode them on the receiving end. I gave up on this since I didn't want to spam everyone on the global network!

You can find out more about the Blockstream Satellite system on their website: https://blockstream.com/satellite/

And you can find instructions on using the system here:https://blockstream.github.io/satellite/doc/sdr.html

I used https://www.dishpointer.com/ to help align my antenna.

I also used https://www.lyngsat.com/ and https://www.satbeams.com/ to identify which satellites I was detecting.

I Found Bitcoin On A Satellite In Space

Running RTL-SDR in your Browser via an HTML5 App

Thank you to Jacobo Tarrio for writing in and sharing his latest project, an HTML5-based RTL-SDR application that runs directly in your browser. Jacobo writes that he'd previously created a Chrome app called FM Radio Receiver for Chrome (which we also posted about previously), but unfortunately, Google stopped supporting Chrome apps.

Jacobo goes on to write:

Last year I started working on it again. I took the original source code, modernized it to use modern TypeScript and HTML5 APIs, and then transformed it deeply to turn Radio Receiver into a general-purpose RTL-SDR application (with a waterfall and everything), which is available at https://radio.ea1iti.es/.
 
You don't need to install anything -- it runs straight on your browser. (Well, you still need to do the usual RTL-SDR driver setup, but other than that...)
 
It supports any computers or Android phones with the Chrome, Edge, or Opera browsers. Unfortunately, it cannot run on iPhone or iPad, or on the Firefox or Safari browsers.
 
For hardware, it works well with the RTL-SDR Blog V3 and V4 sticks (with support for direct sampling on the V3 and for the built-in upconverter on the V4), as well as other R820-based sticks.
 
The source code is available on GitHub under the Apache 2.0 license.
RTL-SDR running in an HTML5 web browser app
RTL-SDR running in an HTML5 web browser app

Updates to Knowle Consultants RTL-SDR Android Apps

Thank you to James Mainwaring, who wanted to write in and share that he has made some updates to his suite of Android apps, which include ADS-B Radar (RTL-SDR), FM Radio (RTL-SDR), Airband Radio (RTL-SDR) and HAM FM Radio (RTL-SDR).

James notes that all his apps now support the ability to connect to an rtl_tcp instance running remotely. He also writes that the ADS-B app now automatically downloads and displays photos of the aircraft being tracked via the API connection to planespotters.net.

ADS-B Radar (RTL-SDR) Android App now shows aircraft images.

DragonBridge: Streaming IQ Data Over 802.11ah HaLow via Two Relay Drones

Aaron, creator of DragonOS, has uploaded a video on his YouTube channel showing him testing out long-range communications via 802.11ah Wireless Networking and a T-HaLow bridge on two drones. 802.11ah (aka HaLow) is a WiFi protocol designed for long range IoT communications of up to 1 km (without obstructions).

In the video, Aaron attempts to stream IQ data with SDR++ over 802.11ah HaLow from a Pi + KrakenSDR operating over 1.6km away. The communication is established via two drones in the air that act as a relay bridge between the two ground stations. Although there are issues with keeping the connection stable, these experiments serve as a great first test of this capability.

Join me on an exciting month long+ journey as I push the boundaries of wireless communication using the Lilygo T-HaLow 802.11ah devices in bridge mode! In this video, I demonstrate how I successfully established an SSH connection from my laptop, across six T-HaLow units—some mounted on two drones and others on the ground—to a Raspberry Pi ground station equipped with DragonOS pi64 and a KrakenSDR.

What You'll See:

Innovative Network Setup: I configured three pairs of T-HaLow units, each pair consisting of an access point and a client. The first pair connected my laptop to the first drone. On each drone, I bridged two T-HaLow units via Ethernet, effectively creating a relay system. The second pair connected the two drones, and the third pair linked the second drone to the ground station Raspberry Pi.

Successful Long-Distance Communication: By the third attempt, I achieved a stable ping across the entire bridge and streamed IQ data from the SDR++ server on the Raspberry Pi to the SDR++ client on my laptop—over a distance of 1.6 km between drones!

Challenges and Triumphs: Experience the hurdles I faced, from connectivity issues to environmental obstacles, and how perseverance led to a successful connection.

Stunning Aerial Footage: Enjoy breathtaking drone shots that not only showcase the technology but also add a visual treat to the technical journey.

Why This Matters:

This project highlights the potential of increasing the standoff distance between equipment using 802.11ah technology, also known as Wi-Fi HaLow. Operating in the sub-1 GHz unlicensed bands, 802.11ah offers extended range and improved propagation through obstacles compared to traditional Wi-Fi frequencies. It's designed for low-power, long-range connectivity with lower power consumption—ideal for IoT applications, remote deployments, and innovative projects like this DragonBridge.

Equipment Used:

Building the DragonBridge: Long-Range 802.11ah Wireless Networking with Drones and T-HaLow Devices

A Tutorial on Setting up a XHSI Cockpit Display with Live Data from an RTL-SDR Receiving ADS-B

Back in 2017, we first posted about using a program called RTL1090-XHSI which is used to display a simulated aircraft cockpit using live data acquired directly from an RTL-SDR receiving ADS-B flight data from nearby aircraft. The ADS-B signal provides not only position and heading data but also information about altitude and speed, which is then used to simulate the cockpit display.

Recently Al wrote in and wanted to share with us a step-by-step tutorial that he has created that shows how to set this up. The guide shows how to download, install and use all the software programs required.

XHSI Cockpit Display with Live ADS-B Data Received by an RTL-SDR
XHSI Cockpit Display with Live ADS-B Data Received by an RTL-SDR