Thank you to Val (LZ2XA) for writing in and sharing with us a program he's created called "Cat2Web," which is designed to keep a ham transceiver and a public browser SDR, such as a KiwiSDR tuned to the same frequency and mode, in both directions. This is useful for amateur radio operators, as they could easily determine if their signal is being heard by a distant public remote SDR station.
Cat2Web (C2W) is a small Windows app that keeps a ham transceiver and a public browser SDR — WebSDR, KiwiSDR, OpenWebRX/OWRX+ — tuned to the same frequency and mode, in both directions.
Besides standard CAT (via OmniRig), it controls FlexRadio 6000/8000 directly over the network (SmartSDR TCP, no CAT cable) and SunSDR via TCI, and it can pull a SpyServer/Airspy stream and demodulate it itself. It also lets you pick the audio output device for the SDR sound, and stores a frequency offset per bookmark.
We note that the program is not open source and has a €20 lifetime license price tag attached to it. However, a demo is available with full sync, but limited bookmarks.
Back in July, we posted about VibeSDR, an AI vibecoded open-source mobile SDR client for rtl_tcp and UberSDR/KiwiSDR/OpenWebRX servers developed for iOS and Android. In that post, Stuart also mentioned that he was developing an Apple Watch app version of VibeSDR that runs directly on an Apple Watch, allowing you to view and listen to the spectrum on your wrist.
The Apple Watch version, called VibeSDR Jr, is now available as a full standalone Apple Watch App, meaning that no iPhone is required. The app costs £0.99 (~US$1.35). As before, Stuart has provided us with 20 free giveaway codes for the VibeSDR Jr App, so be sure to comment on either this post, the Facebook post, or the X post for a chance to win one of the codes.
Stuart has also noted that he now has a live VibeSDR demo running at demo.vibesdr.net, allowing users to see VibeSDR's DSP and server functionality in action. Stuart writes, "There is an RTL-SDR V4C, SDRPlay RSP1B, and AirSpy HF running on that demo server, all connected to the same AirSpy YouLoop with LNA antenna setup. The RSP1B is locked to 2.8MHz - 10.8MHz and can handle 10 users and the RTL-SDR & AirSpy are unlocked frequencies but 1 user at a time, each user gets a 30 minute time slot to play with. All the built in decoders are available and for the FM-DXers there is a full advanced RDS suite measured against a professional broadcast analyser too."
He also notes the following to avoid confusion with the software in the VibeSDR family:
VibeSDR + Buddy: The Main VibeSDR app and the Apple Watch Remote control companion app for that app. VIbeSDR Jr: The full standalone Apple Watch SDR client no iPhone required VibeServer: Built in to Android and standalone apps which allow you to quickly and easily share your SDR’s on a network
Use VibeServer to connect your radio and serve it and then use Jr to listen to it on your wrist, or if you don’t have your own radio Jr is compatible with almost all the same servers as the main VibeSDR app, the only thing it cannot do due to bandwidth/processing requirements is anything that is RAW IQ such as RTL-TCP or SpyServer.
Finally, Stuart notes that the Android version is coming soon and is currently just pending acceptance on the Google Play Store.
Thank you to 'Radio Silence Dev' for writing in and sharing the beta release of his iOS native app, Radio Silence, designed for listening to public KiwiSDR receivers around the world on an iPhone or iPad.
The app streams live audio from the KiwiSDR network, with a live directory showing each node's signal quality, load, and online status. If a receiver drops out mid-session, the app will automatically fail over to another one. There is also a tap-to-tune live spectrum waterfall.
Radio Silence also includes CW, RTTY and FT8 decoders, which all run on-device rather than on the receiver, printing text under the dial as it comes in. Audio keeps playing with the screen locked, and captures are saved to a logbook tagged with frequency, mode, node, S-meter reading and UTC timestamp, with export to ADIF, CSV and WAV. Captures can also be shared as QSL-style reception report cards stamped with the solar flux and Kp index at the time of the catch. NAVTEX and SSTV decoders are in development.
The developer notes that the app is written to be a good citizen on the KiwiSDR network, releasing its channel slot when listening stops and handing it back automatically if playback is left running unattended. Streaming uses about 22 MB per hour.
Radio Silence is free during the beta, and listening is set to remain free at launch, with any future subscription covering software features only. Beta invites can be requested via radiosilencesdr.com.
Radio Silence: Waterfall ViewRadio Silence: Decoding FT8
Thank you to Alphonse Romero for submitting news about the release of his new iOS and iPadOS SDR receiver app called Demod. Demod is a network client that connects to remote SDR servers, so it can be tried out immediately with no dongle needed at all.
The app works as a client for rtl_tcp, SpyServer (Airspy and RTL-SDR), and KiwiSDR, all in a single app. It features a Metal-accelerated waterfall and spectrum display, AM/NFM/WFM/USB/LSB/CW demodulation, and adjustable bandwidth, gain, and squelch. Other features include frequency memories with CSV import and export, AirPlay and Lock Screen controls, and native layouts for both iPhone and iPad. It can also browse and connect to public SpyServers directly from within the app, which is how it can be used with no hardware of your own. The developer notes that it collects no data, with no ads or tracking.
Alphose writes that Demod is a solo project and is available on the US App Store for US$9.99. More information and screenshots can be found on the project website, and the app itself is available on the App Store.
The developer has also provided us with 15 free codes that we will be giving away in one week. To enter the giveaway, simply comment on this post (make sure to include your email address in the comment so that we can send you the code), the X post, or the Facebook post. (UPDATE: ALL CODES HAVE BEEN ALLOCATED NOW, THANKS!)
Back in February, we posted about the beta release of Echo, an iOS app designed for browsing global web-based KiwiSDR, OpenWebRX, WebSDR, and FM-DX software-defined radios. Mark, the developer of Echo, has now officially released the app on the Apple App Store for free.
Echo turns your iPhone and iPad into a global radio receiver. Browse 2,000+ KiwiSDR, OpenWebRX, WebSDR, and FM-DX servers to hear shortwave, aviation, numbers stations, and distant FM in real time.
More information can also be found on the new echosdr.com website.
Echo iOS KiwiSDR, OpenWebRX, WebSDR and FM-DX Browser App
Thank you to Christophe (F4DAN) for writing in about his new project called Wavelingo, an AI real-time shortwave radio translator. The software currently works with the KiwiSDR web SDR network. Christophe has a live public example running at wavelingo.app, however, with a 60-second timeout due to hosting cost constraints. Christophe writes:
Are you listening to a QSO in a foreign language on your transceiver? Click on the closest SDR (KiwiSDR fleet for now, more SDR to come in the future), and get real-time translations.
I opened a telegram channel to share updates and feedbacks on this projects - and provide support.
Back in January, we first posted about "Echo", an upcoming iOS app designed for browsing global web-based KiwiSDR and OpenWebRX software-defined radios.
Mark now notes that Echo is now in beta, and has been released to testers via TestFlight. He notes that new users can access the beta by making a small donation on his Ko-fi page. Mark writes:
Users have already reported being able to listen to some euro ham chat on their bike ride today. Where they’d usually have to put their entire iPhone in that locked guided access mode to block touch inputs on Safari, Echo allows multitasking & lock screen playback. For every SDR, any frequency. Someone else throwing the phone in their pocket & taking their walk with AirPods in their ear listening to CW. This was truly the most requested feature by far.
I’ve made several improvements since we last talked, even added support for not just Kiwi & OpenWebRX but also WebSDR & FM-DX. All built in. Over 2000+ global tuners at people’s fingertips. 11,000+ frequencies in a categorized database.
If you were unaware, OpenWebRX is a piece of server software that allows you to access and share SDRs over a network connection, such as the internet, via a web browser interface. OpenWebRX is a core component of the KiwiSDR, an SDR designed to operate as a shared receiver over a network connection. Around the world, many people have set up public KiwiSDR, RTL-SDR, and other SDR systems accessible via OpenWebRX. Echo is designed to make it easy to search for and view public OpenWebRX receivers on iOS devices.
Thank you to Mark Garrison Jr. for writing in and sharing with us a new iOS app he's developing called "Echo". Echo is an app designed to provide a streamlined mobile companion for the KiwiSDR and OpenWebRX ecosystems. Note that the app is currently not yet released, but Mark is planning a TestFlight beta in February. Follow his Twitter/X @SDRecho for updates, and sign up to the beta tester waiting list if you are interested.
OpenWebRX is a piece of server software that allows you to access and share SDRs over a network connection, such as the internet, via a web browser interface. OpenWebRX is a core component of the KiwiSDR, an SDR designed to operate as a shared receiver over a network connection. Around the world, many people have set up public KiwiSDR, RTL-SDR, and other SDR systems that can be accessed via OpenWebRX. Echo is designed to make searching for and viewing public OpenWebRX receivers easy on iOS devices.
Mark writes:
[Echo] is a native iOS app built entirely in SwiftUI, designed to provide a streamlined mobile companion to the KiwiSDR and OpenWebRX ecosystems.
The goal is to offer a modern interface optimized for iPhone, making it easier to explore the spectrum on the go.
Key Features:
• Global Connectivity: Access any public KiwiSDR or OpenWebRX server via a live global map with 500+ active stations.
• Smart Scans: Station scanner with presets for Shortwave, Ham, and Military bands.
• Audio Intelligence: Integrated recording with speech-to-text transcription for logging signals.
• Native Performance: 100% SwiftUI for smooth waterfall rendering and low battery impact.
The app is currently in active development. I am sharing progress updates and will be announcing the upcoming TestFlight beta over on Twitter at @SDRecho. I’m planning to launch a beta in February.
