CoronaSDR for iOS – A Free Native RTL_TCP Client

Thank you to Silviu YO6SAY for writing in and sharing with us news about the release of his iOS App called "CoronaSDR" which is a native client for receiving from rtl_tcp servers. rtl_tcp is a server program for RTL-SDRs that streams raw IQ data over a network connection.

Unlike Android, iOS does not allow third-party USB devices like the RTL-SDR to run on its devices. But you can set up an rtl_tcp server on a networked PC or Raspberry Pi in your home, and connect to the data stream with an iOS app like CoronaSDR.

Silviu writes:

CoronaSDR is a free, native iOS app that connects to an rtl_tcp server on your local network (no cloud, no subscription).

Current features
• Live spectrum + waterfall (Metal / GPU-accelerated)
• Demod modes: AM / NFM / WFM / USB / LSB / CW
• RF controls: gain, PPM, direct sampling, offset tuning, bias-tee
• Stations with tags + CSV/TSV import/export
• List/range scanning with squelch hold/skip
• Background audio + lock screen controls

Known limitations (early build)
• Built solo so far — no external testers yet
• Most real-world testing to date has been NFM and WFM
• Other modes are implemented, but I’d consider them early until more field feedback comes in

Tested with an RTL-SDR Blog V4 (R828D) on a Raspberry Pi running rtl_tcp.

I’d really appreciate detailed feedback (device + iOS version, tuner type, rtl_tcp command, mode/frequency, and steps to reproduce any issues).
 
CoronaSDR - RTL_TCP Client for iOS Devices.
CoronaSDR - RTL_TCP Client for iOS Devices.
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Exploring the Privacy Risks of Tire Pressure Monitoring Systems with RTL-SDR

Tire Pressure Monitoring System (TPMS) privacy concerns are a topic that comes up every now and then. Most modern vehicles have wireless tire pressure sensors that communicate with the vehicle's computer to alert the driver when tire pressure falls below a safety threshold.

The privacy issue is that these TPMS sensors each transmit a unique identifier, so the computer can know which tire is being measured, and not read other vehicles' sensors by mistake. As TPMS is not encrypted in any way, anyone with an RTL-SDR or other similar radio can receive and decode TPMS messages, including the unique identifier. This raises privacy concerns as this can be used to log the presence and movement of individual vehicles. 

A recent academic paper by university researchers showed how researchers deployed simple RTL-SDR + Raspberry Pi-based receivers along a road over a period of 10 weeks. They showed that TPMS transmissions can not only be used to identify, track, and detect the presence and daily routines of individual vehicles, but also to determine the type and weight of the vehicle via pressure readings.  Interestingly, they also note that variations in the weight of an identified vehicle could indicate, for example, whether a truck is loaded or unloaded, or whether there are additional passengers in a car.

The researchers highlight privacy concerns, noting that such data could be collected and sold by data mining companies without the driver's knowledge. 

RTL-SDR + Raspberry Pi for TPMS Monitoring
RTL-SDR + Raspberry Pi for TPMS Monitoring
The TPMS Monitoring Setup
The TPMS Monitoring Setup
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Frugal Radio: Beginners Guide to P25 Decoding with the Latest DSD Plus Release

Over on his YouTube channel 'Frugal Radio', Rob has uploaded a comprehensive video detailing how to set up the latest DSD Plus release for P25 Public Safety decoding.

Back in December 2025, we posted about how the DSD Plus team released version 2.547. The release had already been available to DSD Fastlane customers, but it is now available to the public. The new version brings various improvements and features, but it also changes the software signal flow that was used in previous versions.

In the video, Rob explains how to set up the new DSD Plus version, including how to use the new FMP24 demodulator with an RTL-SDR. He then goes on to show the various features, like control channel monitoring mode, getting P25 system data, holding and IDing talkgroups, and setting talkgroup aliases.

HUGE free DSDPlus Update 2026 : Decode P25 Public Safety with your SDR and this beginner guide!

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Discovery Drive Campaign Launching Soon

Our Discovery Drive campaign will be launching soon, so make sure to sign up for updates on the pre-launch page!

Discovery Drive is an automatic antenna rotator that is designed to be used with our Discovery Dish product, as well as similarly sized antennas such as Wi-Fi grid and Yagi antennas.

A motorized rotator, such as Discovery Drive, enables precise tracking of fast-moving polar orbiting satellites using a satellite dish or directional antenna. Examples of polar orbiting weather satellites include METEOR-M2, METOP, and FENGYUN. Depending on your location, you may also have access to other interesting satellites that dump data over specific regions.

Apart from public weather data, operators and enthusiasts might be interested in using Discovery Drive to track CubeSats, and amateur radio operators may wish to track amateur radio satellites.

Amateur radio astronomy hobbyists can map the galaxy in the hydrogen line spectrum using Stellarium, or custom software to aim a Discovery Dish with H-Line feed, allowing you to scan multiple parts of the sky in one night.

Please check out our promo video below!

Discovery Drive Promo Video

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Echo iOS KiwiSDR & OpenWebRX App now in Beta Testing

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.

EchoSDR Beta Screenshots
Echo iOS Beta Screenshots
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Khanfar Software: Analog Radio Hunter

Recently, M. Khanfar released a new free program, "Analog Radio Hunter," described as a "professional RF analysis and monitoring application built around GNU Radio and Fosphor." The software currently supports RTL-SDR, Airspy, and HackRF. Khanfar writes:

Analog Radio Hunter is a professional RF analysis and monitoring application built around GNU Radio and Fosphor.

It is designed to scan large RF spans, quickly lock onto active signals, and monitor analog transmissions with NFM, AM, or WFM audio demodulation.

  • Real-time FFT + waterfall spectrum display
  • Fast scan with dwell, pause-on-squelch, and skip-ignored channels
  • Detection list with hits, timestamps, and smart deactivation
  • Favorites profiles with monitor and favorites-only scan modes
  • Built-in recorder with auto-record and event log
  • Dedicated WFM broadcast receiver with presets
  • Multi-SDR device support (RTL-SDR, Airspy, HackRF) with auto-detect and device switching
  • NFM and AM audio demodulation (in addition to WFM)
  • Peak-follow in span (auto-tune to strongest signal inside the current MS/s window)
  • Frequency list filtering to skip/mute ignored channels
  • Scan and detection profiles (save/load named presets)
  • PPM correction for RTL-SDR calibration
  • Spectrum interaction controls (cursor readout, click-to-tune, wheel step, drag-pan)
  • Recorder options (record when muted, timestamp/frequency in filename, beep on favorite)
  • WFM de-emphasis selection (50/75 µs) and preset management
  • Audio Output menu with refresh (route audio to speakers, VB-Cable, or USB output)
  • Signal Stability Filter with Min Open + Grace timing and per-target routing
  • Histogram IQ Rec with live IQ follow controls and inspectrum integration
  • Auto Squelch Calibrate (noise floor + margin) for faster field setup
  • Smart Deactivate dual-layer logic (time-based + hit-rate busy rule)
  • Favorites cooldown auto-reactivation for busy channels
  • Favorite TX tones (Tone 1-9), edge selection, and tone test buttons
  • Learning Mode hover guidance for faster onboarding
  • Status bar live metrics for Last, Active, Favorite, Peak SNR, and Level
Unique scanning and detection approach: Traditional sweep scanners only see the center frequency they step to. Analog Radio Hunter monitors an entire chunk of spectrum at once and reacts to peaks inside it. That is a major differentiator.
 

High-Impact Capabilities

  • Wide-span reactive scan engine that hunts activity across a full chunk, not one center point at a time.
  • One-click IQ capture and histogram visualization with follow and idle flow controls.
  • Carrier-resilient channel management using Smart Deactivate + favorites cooldown logic.
  • Field-ready setup speed using Auto Cal squelch and persistent live status metrics.
  • Operator-selectable audio routing to speakers, VB-Cable, or USB audio output devices.
  • Operational clarity from GUI color heatmaps, scan debug reasons, and learning-mode tips.

Signal Stability Filter: Logic and Tuning

  • Purpose: reject short squelch flicker and noisy open/close chatter before actions trigger.
  • Min Open (ms): raw squelch must stay open this long before stable-open is accepted.
  • Grace (ms): stable-open is held briefly after raw close to avoid tiny dropouts.
  • Apply targets: Detection, Rec+Alerts, Scan Hold, and optional Audio Out gating.
  • Start values: Min Open 150-250 ms, Grace 40-80 ms, then tune by channel behavior.

Like his other software, which we previously covered, it is free but not open source. Anti-virus programs may flag the software as suspicious due to heuristics. We believe this to be a false positive, but as with all software that isn't open source, we recommend being highly suspicious and only run it in a sandboxed environment like a VM to be sure.

M Khanfar Analog Radio Hunter
M Khanfar Analog Radio Hunter
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Iridium-Sniffer: A Standalone Iridium Satellite Burst Detector and Demodulator

Thank you to Aaron, who is most well known for creating the DragonOS distribution, for writing in and sharing with us a new open-source program he's recently released over on GitHub.

The program is called 'Iridium-Sniffer', and it is a standalone Iridium satellite burst detector and demodulator written in C. Typically, gr-iridium has been used for Iridium demodulation in the past, but it can be clunky and slow on lower-power embedded systems like the Raspberry Pi, as it requires the large GNU Radio dependency.

The program is compatible with iridium-toolkit, which performs the actual decoding and analysis of the Iridium packets demodulated by iridium-sniffer.

If you're not familiar with it, Iridium is a large global communications satellite constellation that provides services such as voice, messaging, and data. An antenna like our RTL-SDR Blog Active Patch antenna, combined with an SDR, can be used to receive these signals. Some data on Iridium is encrypted, but there is some unencrypted data that can be decoded when combining tools like iridium-sniffer and iridium-toolkit.

Iridium-sniffer is compatible with the HackRF, BladeRF, USRP (UHD), and SoapySDR (which includes RTL-SDR). Note that higher-bandwidth SDRs can receive much more of the ~30 MHz Iridium band, and therefore decode more data at once.

The Iridium Satellite Constellation
The Iridium Satellite Constellation
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xSDR Crowdfunding Campaign Now Live

Back in January, we posted about the upcoming crowdfunding campaign for Wavelet Lab's M.2 form factor xSDR software-defined radio product. The campaign went live a few days ago, with the xSDR priced at US$549 and a delivery date of July 15, 2026.

xSDR is a compact, single-sided M.2 software-defined radio designed for seamless integration into modern computing platforms. The “x” stands for extended; xSDR delivers extended bandwidth in the same minimal footprint as our previous model, uSDR. With 2x2 MIMO RX/TX channels, a wide 30 MHz–3.8 GHz tuning range, and up to 122.88 MSPS sampling and an updated FPGA, xSDR is a flexible platform for embedded RF, wireless research, signal intelligence, and rapid prototyping.

Designed to fit the M.2 2230 A+E-key form factor (30 mm × 22 mm), xSDR plugs directly into laptops, tablets, smartphones, and embedded computers. When paired with the wsdr.io web platform, it enables instant creation, control, and sharing of RF applications right from a browser, with no complex drivers or software setup required.

We note that sSDR, their higher end software defined radio product is due to be released for crowdfunding in March.

xSDR - A tiny, single-sided M.2 software-defined radio with 2× RX / TX channels up to 3.8 GHz

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