Over on YouTube, we've seen a talk by Mark Jessop that may be interesting to some readers, as it covers Amateur Radio Direction Finding / Fox Hunting with the KrakenSDR, as well as various other radio tools. If you are unaware, KrakenSDR is our 5-channel coherent RTL-SDR based software defined radio system, designed for coherent applications like radio direction finding.
In the talk, Mark explains the amateur radio fox hunting sport, which involves the organizer hiding a transmitter somewhere in a defined area and having participants search for it using just its radio emissions. He goes on to show the different types of antennas, radio systems and vehicle setups participants used.
Mark further explains that on his particular vehicle, he uses a KrakenSDR as the primary receive system. He explains how the KrakenSDR works, how he integrated it into this vehicle and the custom software and LED display that he is using with it.
ARDF at Mt Gambier - by Mark VK5QI and Grant VK5GR - AREG September 2025 Presentation
Thank you to Alexandre Gellibert for writing in and sharing his new Android App, "SDR ProTrack." SDR ProTrack is a radio direction-finding app that uses an RTL-SDR and directional antenna to determine a bearing towards a transmitter.
Interestingly, Alexandre notes that this app was initially developed to track Asian hornets, a bee-killing pest. With hornet tracking, a miniature RF transmitter is attached to a caught hornet, and the hornet brings it back to the nest. RF tracking techniques can then be used to find the nest.
It's possible to determine the bearing toward a transmitter by using a receiver such as an RTL-SDR paired with a directional antenna like a Yagi. Directional antennas have high sensitivity in one primary direction and significantly lower sensitivity in all others. By rotating the antenna until the strongest signal is identified, you can establish the precise bearing angle. Typically, following this bearing will guide you directly toward the signal's origin.
Alexandre wrote in an email to us the following:
Just to let you know we just launched a new Android app compatible with RTL-SDR dongles (though mostly tested on RTL-SDR v4).
App is free to use. Advanced features (like Compass to point the signal potential source) are for premium users.
It's plug and play, easy to use, much more user friendly than SDR++.
Any feedback is really appreciated :)
If you want to know more about the project or the 2 developers behind it (we develop it in France to be able to track asian hornets that kill all the bees), please feel free to contact us.
And the Android page describes SDR ProTrack in the following way:
Unlock the power of radio tracking with SDR ProTrack! Transform your Android smartphone into a signal-tracking powerhouse using an RTL-SDR dongle and a directional antenna. Affordable, versatile, and perfect for enthusiasts, researchers, pros or anyone tracking signals—like Asian hornets or wildlife.
★ Key Features ★
• Automatic RTL-SDR dongle recognition and connection (free) • Spectrum Visualization (Free): View signal shapes in the frequency domain effortlessly. • Compass (Premium): Pinpoint the strongest signal direction with precision. • Signal Strength Display (Premium): Monitor signal power with an intuitive interface. • Custom Settings (Premium): Adjust bitrate, sample rate, and frequency sensitivity to your liking.
★ Requirements ★
• Requires an external RTL-SDR device. • Check compatibility: https://osmocom.org/projects/rtl-sdr/wiki
Need an RTL-SDR dongle, emitters, receptors, or antennas? Visit our website: https://www.intuite.fr/en_GB/pricing
★ About Us ★
Intuite is a company specialized in locating Asian hornet nests. We developed SDR ProTrack to provide a robust, cost-effective solution for radio signal tracking, combining innovative technology with our expertise in signal detection.
★ Open Source Community ★
Join our mission to advance radio tracking! Our open-source library, RTL-SDR Bridge Android Lib, powers SDR Pro Track. Contribute to development, report issues, or explore the code at https://github.com/alexandreGellibert/RTL-SDR-Bridge-Android-Lib. Support our work and help shape the future of signal tracking!
Download SDR ProTrack today and start tracking signals like a pro!
The talk focuses on using SDR hardware such as the RX888, RTL-SDR, and Airspy devices combined with directional antennas for radio direction finding. Interestingly, they also discuss using ultrasonic microphones to find power line noise from bad transformers or insulators. The talk also focuses on ensuring that your SDRs receive real signals and what noise might look like on the spectrum.
This talk provides a comprehensive guide to identifying and locating radio transmitters. Learn about practical techniques, common tools, and methodologies from decades of combined experience finding, squashing, and mitigating against radio frequency interference.
Supercon 2024: Justin McAllister and Nick Foster - How to Track Down Radio Transmissions
Khanfar Spot Scanner is a powerful and feature-rich spectrum analyzer designed for radio frequency enthusiasts, wireless security researchers, and professional RF engineers. Supporting multiple SDR hardware devices including RTL-SDR, Airspy, and HackRF, this software provides comprehensive spectrum visualization, automated signal detection, and in-depth analysis reporting.
Khanfar Phase-Based DF is advanced direction finding software that uses phase difference analysis to determine the bearing of radio signal sources. Unlike traditional direction finding systems that rely on directional antennas and signal strength comparison, this software utilizes an array of omnidirectional antennas and sophisticated signal processing algorithms to analyze the phase relationships between received signals.
We want to add to this a note that we're not entirely sure how this software can possibly work as phase based direction finding with RTL-SDRs requires synchronized clocks, and sample and phase alignment to be performed via a correlation with a noise source first which this software does not enable. Without those steps taken results will be totally random. We gave this software a brief test with a KrakenSDR, but as expected, did not see the results we expected. We're keen to hear feedback from other users.
Khanfar RTL-SDR IQ Live+Rec+Playback is a powerful, feature-rich spectrum analyzer application designed for RTL-SDR devices. This professional-grade software provides real-time RF spectrum visualization with GPU-accelerated rendering, comprehensive IQ data recording capabilities in multiple industry-standard formats, and advanced playback features for signal analysis. With IQEngine and IQ Analyzer integration, you can seamlessly export your recorded signals for comprehensive online analysis, visualization, and collaboration.
Recently, on Feb 21, we posted news about the release of some spectrum analysis and FM demodulator software from M. Khanfar. Now he has just released his latest software "Khanfar Direction Finder" (scroll to the end of the page), a Windows radio direction finding tool for RTL-SDR dongles.
Khanfar Direction Finder appears to work on the principle of power measurements through the use of directional antennas. Four directional antennas are connected to four RTL-SDR dongles positioned in the N/S/E/W directions.
The antenna pointing towards the signal source will receive it stronger and the antenna pointing away from it will receive it weaker. The two other antennas may receive the signal with some intermediate strength based on the angle. The software automatically combines the power information from all four antennas, resulting in a bearing.
The 'Quintet' version of the software also contains a map that can be used to plot the determined bearings.
Both versions of the software are free to download but not open-source. As mentioned in the previous post, antivirus software can flag M. Khanfar's software as suspicious. We suspect these are false positive results due to the PyInstaller system used to create the exe, but please take your own precautions just in case.
Khanfar Direction Finder Compass ScreenKhanfar Direction Finder Map Screen
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
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.
Over on YouTube The Comms Channel has uploaded a video showing how they used a KrakenSDR to track down the location of an ATIS transmission tower.
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.
Airports typically have an ATIS (Automatic Terminal Information Service) transmission tower that broadcasts audio of recorded information such as weather, runway conditions, and any important notices.
In the video, they use the KrakenSDR to track down the location of an ATIS transmission tower at their local airport. In the future, they intend on using the KrakenSDR to help track down Meshtastic radios.
Radio Direction Finding with the KrakenSDR | Radio Direction Finding Series
