SDR++ is an open source receiver program compatible with most software defined radios including the RTL-SDR that has been going through rapid development making it now one of the top software choices. In runs on almost every platform, including Windows, Linux, MacOS and Android.
One feature that SDR++ has is it's remote server. This is similar to applications like rtl_tcp which allow an SDR on a remote device like a Raspberry Pi to be accessed over a network.
Over on YouTube, Matt from Tech Minds has uploaded a video showing how to run the SDR++ Server on MacOS, Windows and Raspberry Pi platforms.
Why use this app? It makes it easy to slog through lots of recording files, looking for interesting signals. Load a file, and a waterfall for the entire file is created. You can scroll around, and if you see anything that looks interesting, you can drag select it, and then demodulate it. You can even save the demodulated audio as a WAVE file, that you can listen to later, send to someone else, or play into your digital decoding software, if it is an RTTY, SSTV, etc. transmission.
Support for other SDR recording file formats is possible, you'll need to work with me by providing sample files and details on the format. This program is presently for macOS only. Support for Windows may happen... stay tuned!
Thanks to Doug Ward (@dsward) for letting us know about his new RTL-SDR compatible MacOS based app called LocalRadio. LocalRadio is an open source web browser based app that connects to a MacOS server running an RTL-SDR. The software allows you to listen in on any frequency supported by the RTL-SDR in AM or FM modes, and audio is capable of being streamed to multiple devices via a built the LAME MP3 encoder, EZStream and Icecast server. It does not provide an FFT or waterfall display however.
The software introduction reads:
LocalRadio is an experimental, GPL-2 licensed open-source application for listening to “software defined radio” on your Mac and mobile devices. With an inexpensive RTL-SDR device plugged into the Mac’s USB port, LocalRadio provides a casual listening experience for your favorite local FM broadcasts, free music, news, sports, weather, public safety and aviation scanner monitoring, and other radio sources.
LocalRadio’s easy-to-use web interface allows the radio to be shared from a Mac to iPhones, iPads, Android devices, and other PCs on your home network. No additional software or hardware is required for sharing with mobile devices, simply use the built-in mobile web browser to connect to LocalRadio and tune to your favorite stations. You can also listen to LocalRadio audio on your Apple TV and other AirPlay-compatible devices.
LocalRadio does not provide features like FFT waterfalls, panadapters, or signal recording that are found on other SDR software. For those features, GQRX for Mac is highly recommended. GQRX is a good way to discover radio frequencies that can be used with LocalRadio.
LocalRadio is intended for use as in-home entertainment, using a local area network with a private IP address. It has not been tested with a public IP address, particularly for security testing, therefore it is not recommended for that purpose. For simply listening to LocalRadio on the Mac with the RTL-SDR device plugged in, no network is required at all.
This software decoder appears to be an excellent choice for those people who want to perform their reception and decoding of Meteor M satellites all in Linux. Previously as explained in this previous post, you were able to receive the QPSK data in Linux with an RTL-SDR and a GNU Radio program, but then you’d still need to boot into Windows or run Wine to run LRPTofflinedecoder in order to generate the image. Now it appears that the image generation can be performed natively in Linux too with meteor_decoder. This help with creating portable automated Raspberry Pi based Meteor M decoder servers.
Meteor M is a class of Russian weather satellites that transmit live weather images of the earth as they pass over your location. They are somewhat similar to the NOAA satellites, although the Meteor satellites transmit higher quality images via a digital LRPT signal, rather than the analog APT signals used by NOAA. With an RTL-SDR, an appropriate antenna and decoding software they can easily be received.
Over on YouTube user GetOffMyHack has uploaded a video that shows his development of a Mac based general purpose tuning app for the RTL-SDR, which was written in the Swift programming language. Swift is a programming language which is designed for creating apps for a wide range of smart Apple devices.
GetOffMyHack’s program currently has a spectrum and waterfall view, can tune to any frequency, demodulate NFM and AM, and it also has a built in CTCSS decoder. At the moment the software and code is unreleased, but he writes that in the future the code will be released and made open source once he reaches the next version in the development cycle. Keep an eye on his YouTube channel for any updates.
Recently programmer Erik Larsen wrote in to us to let us know about a MacOS application he has been developing to receive temperature and humidity data from Oregon Scientific v2.1 sensors. Oregon Scientific manufactures popular electronic weather stations that transmit data from remote sensors wirelessly. Using an RTL-SDR and Eriks software it is possible to receive the weather station data on a Mac computer and display the data on a GUI. The software can be downloaded from the releases section on its GitHub page.
niliBOX is a multiplatform software package in beta release that can be used to manage radio devices such as Icom radio scanners and RTL-SDRs remotely or locally. It is the evolution of the older 'PCR Anywhere' software which was specifically designed for controlling Icom Radio scanners.
Over on YouTube user Danny Shortwave And Radio DX has uploaded a video demonstrating the RTL-SDR module being used in niliBOX with his RTL-SDR Blog V3 SDR. He writes:
niliBOX developed a software for various models of computer controlled radios and also for the RTL-SDR software defined radio. I will demonstrate this by running the software while tuning the mediumwave stations. The antenna I'm using is the MLA-30 active loop antenna. This is their first initial release of this software. I will make a series of videos showing this program working. Stay Tuned. This is Version 1.0.0
They currently have Windows 64 Bit. Tested on Windows 7, 10 and 11. They also have Linux version, tested on Ubuntu and Centos 64 Bit. And also a Apple Mac version, tested with MacOS 10.14, 10.15, 11 and 12. They are also coming soon with Android and IOS versions.
Brief Demonstration of new niliBOX software for the RTL-SDR V.3 SDR USB Dongle
Paolo Romani (IZ1MLL) has recently released version 5.3 of his SDRSharp PDF Guide. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book" and choose your language.
As before the document is a detailed guide about how to use SDRSharp (SDR#), which is the software provided by Airspy. While intended for Airspy devices, SDRSharp also supports a number of third party SDRs, including the RTL-SDR, and it is the software we recommend starting with when using an RTL-SDR.
Youssef Touil hasn't rested for a moment and the SDR# releases have been moving forward in leaps and bounds with new Denoisers (NINR), CCC, Audio/Baseband records and the new menu features.
I also had to re-update my Big Book PDF to v5.3 as a result!!
I have also implemented the SpyServer section a lot in multi OS and a chapter "Ideas and Suggestions" with two paragraphs: SDR & MacOS and the other using SDR# with two multiple monitors.