Category: RTL-SDR

A USB-C Mod for RTL-SDR Blog V3/V4 Dongles

Over on GitHub, umbertoragone has uploaded some schematics for a USB-C modification he's made for RTL-SDR Blog V3 and V4 dongles. The modification removes the stock USB-A plug on the dongle, and instead replaces it with a USB-C connector mounted on an adapter PCB.

The repo contains all the gerbers, BOM, and assembly details required to replicate the modification. He notes that he is also selling a pre-made USB-C adapter board over on his Tindie or Lectronz store for US$4 (currently out of stock).

Let us know in the comments if you would be interested in seeing an official USB-C version of the Blog V3 and V4 line of dongles. Previous polling has indicated that USB-A is still the preferred choice by a wide margin, but attitudes may have changed over the years.

A USB-C Modification for RTL-SDR Blog V3 and V4 dongles.
A USB-C Modification for RTL-SDR Blog V3 and V4 dongles.

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

Saveitforparts: Hacking an Motorized RV Satellite Dish for Tracking LEO Satellites

Over on the saveitforparts YouTube channel, Gabe has uploaded a new video showing how he's hacking an old motorized Wineguard RV satellite dish for tracking low earth orbit satellites, such as the NOAA and Meteor weather satellites as well as the US Military's DMSP system.

The motorized RV satellite dish was originally intended for tracking TV satellites, but by connecting to the serial port on the control unit, Gabe is able to control the satellite dish through his own code.

In this video I'm creating a motorized satellite tracker for S-Band signals. S-Band includes NOAA weather satellites and the US Military's DMSP system (it's also the radio band for WiFi, which I might look at later).

I'm using a Winegard brand "Trav'ler" antenna designed for use on campers and recreational vehicles. It has a built-in three-axis motor system for pointing at TV satellites, but I wanted to use it for tracking satellites closer to earth. Since a low-orbit satellite like NOAA 18 or DMSP passes overhead in about 10 minutes, I need to move the dish faster and more precisely then it was intended for.

This project is still ongoing, and I don't yet have the code up on Github. When I do, it will be available at https://github.com/saveitforparts/ alongside the code for some similar antennas I've hacked in the past.

The serial cable I'm using is described here: https://saveitforparts.wordpress.com/2023/12/29/another-portable-radio-telescope/

Modifying RV Satellite Dish To Track Low-Earth-Orbit Satellites

Setting up a Dual RX System with an SDR and Ham Radio Rig via an SDRSwitch

There are two common options when using an SDR together with a ham radio rig. You can either create an IF tap within your ham radio and connect the SDR to that, or connect the SDR directly to the antenna via a switch that switches the SDR out when transmitting.

Over on YouTube, Ham Radio DX has uploaded a video discussing the latter option and revealing its advantages. In the video, he mentions results by HB9VQQ that show that connecting an Airspy HF+ directly to an antenna via an SDR switch from SDRSwitch.com results in 60% more spots on WSPR, compared to using an IF tap from an FT450D ham radio rig.

He goes on to explain and demonstrate his setup and the recommended switch that he is using, which is the SDRSwitch by N2EME, available at SDRSwitch.com. He notes that this switch is recommended due to its very low insertion loss and high isolation specifications and compares it against an MFJ switch, which has some rather terrible specifications.

Add a SDR Receiver to ANY Ham Radio Rig!

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

Saveitforparts: Testing a 3D Printable Satellite Antenna for NOAA, Meteor and other Polar Orbiting L-Band Satellites

Over on the saveitforparts channel, Gabe has uploaded a video showing a 3D-printable helicone antenna for receiving weather images from polar-orbiting L-band satellites like NOAA and Meteor. This antenna has become popular in the community as it is relatively easy to build, lightweight, and small enough to be handheld. The 3D model files are available on Thingiverse.

In the video, Gabe shows that initially, he had multiple failed print attempts on the helical scaffold due to the legs warping. He was able to solve this and get a working print by slightly modifying the 3D model to have additional center supports. He then goes on to show the rest of the build, which involves coiling the helix antenna, cutting the reflector out of sheet metal, screwing together the reflector supports, and mounting the reflector mesh.

Finally, he shows that he was able to get successful image reception from NOAA HRPT satellites using hand tracking, with a phone running an RTL-SDR and SatDump for tracking and decoding.

This 3D-Printed Satellite Antenna Is Fantastic!

Demonstrating the Effect of Square Wave Harmonics with a HackRF and RTL-SDR

Over on YouTube Paul from 'Tall Paul Tech' has uploaded a video that explains and demonstrates the effect of square wave harmonics using a HackRF and RTL-SDR.

Paul starts by using GNU Radio to explain how square waves are created from a set of sine waves, and how a signal can essentially turn into a square wave if it is too strong and clipping the analog to digital converter (ADC). The result for your SDR is that harmonics of strong signals can show up at incorrect frequencies.

Later in the video, Paul shows this effect using a HackRF and RTL-SDR.

Effect of harmonics and interference from clipping and square waves

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