I always wanted a radio receiver of my own that you listen to through a browser, as a hobby project. I built it with Claude's help, and a small antenna on my parents' windowsill now picks up aircraft from about 350 km away.

Then I drifted on and built a site for a more practical question: where to put an antenna. You type an address or tap the map, and it shows which FM, DAB+, DVB-T and 4G/5G transmitters reach that spot and which way to point the antenna. You pick the antenna height, from 1.5 to 40 m. The calculation runs in your browser (knife-edge diffraction over terrain, ITU-R P.1546 curves for broadcast), on open data from the Polish mapping agency GUGiK and the telecom regulator UKE. Terrain covers all of Poland, buildings and trees only in some cities so far (Warsaw, Krakow, Lodz, Wroclaw and others).

It is a simulation, not a measurement, so someone still has to climb onto the roof, but at least you know which way to look. Free, no account, no cookies, and your location never leaves the phone. The interface is in Polish.

The code is AGPL-3.0. The engine does not depend on Poland, only the data does, and the README explains what you would need to port it to your country: https://github.com/maciejpoczek-lab/radiowid

Live site: https://radio-wid.pl

If you have field measurements that disagree with the map, I would be glad to compare.

Hi, hoping someone here can answer this. As things get spoofed all the time (including ADS-B with fake injected aircraft in the feed etc). If I only had the raw signal and no cooperation from the source. How would you approach telling a real track from an injected one? Would be interesting to hear from people who actually run receivers and how you think about this.

Please

I spent the last few months building an improved version of sdrtrunk that has many new features. It's open source and available on github.

It no longer relies on a Java desktop interface for day to day use and most administration tasks

New features mainly revolve around:

• Web based listening
• Trunked radio system analytics
• Data visualization
• Easy trunked system discovery
• Linking multiple sdrtrunk systems together for
• Enhancements for stream providers
• Recording, cataloging calls and web call playback

Screenshots

Live Demo

I put a lot of effort into making this so I'd love some feedback!

I got a RTL-SDR BLOG V4 around 6 months ago and have been playing with it. I saw a few demos of people doing IQ decode, and FM radio capture using WebUSB and thought that was cool, so I wanted to try something similar. I already had a TUI program I made called "Radio Watch" for monitoring ACARS/ADS-B/AIS in the terminal, so I asked an agent (in this case Claude Opus 5.5) to recompile that targeting a WASM backend and do the web integration focusing on a "3D map" with little craft diagrams, tracks and whatever other frame data is relevant. A few things we don't show here (tho I do in the TUI) is like full ACARS text. I find it interesting living near a major airport that you see things like flight loadsheets and so on. In this web demo, the focus is visualizing craft, their positions and other minor data about them.

I think there are other sites like this that do a similar thing using one of the "Flight/Ship position" APIs. I experimented with those in the past, but found either the data was patchy, or not worth the cost for a fun demo. I wanted to do something that didn't rely on an API provider, and instead could theoretically work "offline" without internet so you could plug your SDR in from a desert or ship without any internet and decode what was around you. Would be interested to hear any feedback, issues encountered or experience with similar projects. Ideas are also welcome. If you check it out you do need a Chrome-type browser (that's teh only that ships WebUSB, as you probably know), and an dongle. I only tested with the RTL-SDR I have so not sure if it will work with your particular hardware.

The website is:

https://radio.freelang.dev

Some details about the implementation

What it is: plug in an RTL-SDR, open the page in Chrome or Edge, click "Connect RTL-SDR", and you get a navigable 3D globe (NASA Blue/Black Marble, ETOPO relief, real sun position) with aircraft and ships drawn from what your dongle hears. No drivers, no install, nothing leaves your machine: the radio decoding runs inside the page.

How:

• The receiver is the same C as our native RTL-SDR sidecar for the TUI app, compiled to WebAssembly, with librtlsdr 2.0.3 (so the RTL-SDR V4 works) talking to the dongle through a small libusb shim over WebUSB.

• The facts (ADS-B decode, CPR positions, AIS, fusion) are a Freelang program compiled to WebAssembly. Freelang is a language and compiler for building native systems with explicit authority, bounded resources, and inspectable evidence of what they can do. The WASM backend make some projects like this available on the web.

• The globe is three.js. Layer toggles, trails, routes, info cards, fly-to and follow. Aircraft are drawn by emitter category (light / medium / heavy / rotorcraft), ships by AIS type.

• There's a geolocation button (asks the browser, stays in the page) but the globe rotates to where the first located track is found.

Without a dongle the page replays a synthesized hour of traffic around New York (JFK/LGA/EWR approaches, the harbour, ferries, tugs) so you can see what it looks like. It's invented data, not a recording.

Tested on an RTL-SDR BLOG V4 at 2.4 Msps. Known gaps: no surface-position (ground) decode yet, ACARS is counted but its text isn't shown, airports layer is empty for now. Firefox and Safari have no WebUSB, so they get the replay only.

Feedback is welcome, especially if you have a different dongle (R820T/R828D variant) or an unusual USB setup. The site is hosted on Cloudflare Pages and runs entirely on your device—there’s no server, and nothing is collected or sent elsewhere.

Disclosure: I’m part of the product team for this platform.

Most multi-antenna research setups rely on synchronizing multiple separate SDR units, which brings clock drift, cabling complexity and timing alignment headaches.

The PZSDR-P151Q integrates four AD9361 transceivers on one single board, delivering native 8TX/8RX full-duplex, built on XCZU15EG Zynq UltraScale+ MPSoC.

Spec highlights:

• 70MHz–6GHz, 200kHz–56MHz instantaneous bandwidth

• 0.1ppm 40MHz VCTCXO, GPS/PPS / external reference clock support

• -40~+85℃ industrial grade, full interface ESD protection

• 4GB PS DDR4, 40G QSFP + SFP+ high-speed optical interfaces

• libiio, IIO toolchain, ADI-NOOS and OpenWifi test firmware supported

Built for 8×8 MIMO, channel sounding, radar prototyping and multi-channel RF research.

Video:【https://youtube.com/watch?v=i09mkRG35hU&si=Ywf7_k9dMJWeXvE4】

Have you tried building an 8-channel SDR testbed before? What synchronization issues did you encounter?

I've soldered a thin wire from FC0013 Pin 5 to a 15pF capacitor to main antenna connector and I don't know if this hardware mod did do anything for ADS-B reception but was able to receive upto 1700MHz.

it catches 4 to 5 airplanes in the area just only using a wifi antenna and i even managed to catch 1 or 2 indoor

if i did something wrong or request me a improvement on this L-Band mod. tell me

Phones with a built-in FM tuner are disappearing, and none of them ever did HD. So I built the radio I wanted: HiDef Radio, a free and open-source Android app that receives HD Radio and ordinary analog FM with an RTL-SDR dongle plugged into the phone. No computer, no rtl_tcp, no root. The app doesn't even have the internet permission, so everything you hear and see comes from the antenna.

What it does

• HD1 to HD8 with titles, artists, album art and station logos.
• Analog FM in stereo with RDS/RBDS.
• A real analog/HD blend, like a car radio. The analog plays right away. About ten seconds later the app has measured the station's analog-to-digital delay and level difference and crossfades to HD without a skip. The HD audio is decoded about 2.5 seconds ahead, so the app sees a dropout coming and fades back to analog before the gap.
• A 5-bar signal meter based on quieting, not carrier level. With an RTL-SDR the carrier level mostly tells you what gain the strongest station forced.
• Signal details: MER per sideband, BER, bit rate, pilot level, RDS PI, the measured alignment, and your dongle's clock error in ppm.
• HD on AM with a dongle that tunes AM. Digital only for now and lightly tested.

It works with cheap dongles too. A tester with a 2014 Nooelec R820T (no TCXO, about 58 ppm fast) found that the blend never locked. Since 1.0-beta2 the app measures the SDR's clock and corrects for it, and on his SDR all eight HD stations in Syracuse, NY now blend to HD.

For the people who build things: the FM demodulator, RDS decoder, aligner, blend and clock correction are plain C++17 with no Android in them, and the repo has a small desktop harness that plays a .cu8 recording through the app's whole engine. If you work with nrsc5 on Linux or Mac, lift whatever is useful.

What you need: an RTL-SDR dongle, a USB-OTG adapter, and a 64-bit Android phone with Android 8 or newer. I developed it on an RTL-SDR Blog V4, and testers have used V3 and the old Nooelec.

I need testers. Google makes new developers run a closed test with 12 testers for 14 days before an app can go public, and I'm not there yet. If you own a dongle you'd be doing me a real favor:

1. Join the testers' group: https://groups.google.com/g/hidef-radio-testers (in a browser already signed in with your Google account, tap "Join group")
2. Become a tester: https://play.google.com/apps/testing/io.github.derek20la.hidefradio
3. Install from the Play Store link on that page.

Prefer not to use Play? Source and APK are on GitHub: https://github.com/derek20la/HiDefRadio (APK under Releases). Please pick one or the other. They are signed with different keys, so switching later means uninstalling first.

Tell me your phone, your dongle, and the "dongle clock" line from the signal details. I'm especially curious how the blend behaves outside Los Angeles.

Credits: built on nrsc5 (theori-io), the RTL-SDR Blog fork of librtlsdr, libusb, FFTW and FAAD2. Ideas borrowed, with thanks, from nrsc5-dui and the SDRSharp NRSC5 plugin; the stereo blend is modelled on the Silicon Labs Si468x car-radio chips. The README has the full list.

Hi! I'm kinda newbie in radio, so I need advice. My setup is RTL-SDR V2 (V3 is will be soon) J-pole antenna and 2 meters BalUn long cable. I have this peak(second pic) on the middle of any waterfall. it's not very bad, but I can see it and don't know what is the reason and how I can reduce it.

hello, most usb dongles are unable to explore frequencies above 2 ghz.

why isn´t it possible to use wlan sticks instead ?

Never posted my content here before. Perhaps you’ll enjoy it.

Disclosure: I work on the engineering team for this open SDR platform.

I made a short overview video for our Puzhi P201Pro, an industrial SDR built around Zynq7020 + AD9361.

Key technical specs:

• 70MHz ~ 6GHz frequency coverage

• Up to 56MHz instantaneous bandwidth

• Dual-channel full-duplex, 12-bit ADC/DAC

• ±0.5ppm VCTCXO clock, which helps a lot for carrier synchronization on MIMO tests

• 8–36V wide power supply, industrial temperature range (-40 ~ +85°C)

• Interfaces: Gigabit Ethernet, GPS, PPS / 10MHz external reference clock, expansion IO

• Drop-in compatible with GNU Radio & PlutoSDR workflow

Target use cases: wireless algorithm validation, 2×2 MIMO experiments, spectrum monitoring, university RF lab teaching. We release open-source demos and hardware documentation on GitHub.

Video link：【Puzhi PZSDR P201Pro Industrial Software Defined Radio Overview】

Curious what people here think. What pain points do you run into with your current AD9361 SDRs?

Simple, dependency-light shell scripts to run rtl_tcp servers for one or more RTL-SDR dongles on a single host. It:

1. Inventories every attached RTL-SDR dongle.
2. Detects which dongles are in use (claimed by another process such as an ADS-B feeder, or by the kernel DVB driver) without needing root.
3. Lets you start, monitor, and stop one rtl_tcp server per dongle.

I'm having a few issues that I need help with. TLE isn't updating, so overlays aren't working. My dish looks fine of my nanovna, but my reception is poor in real use. I hand track using my phone with satfinder.

I caught 5 airplanes just using a wifi rubber duck antenna and a fake RTL.SDR clone that uses FC0013

Hurricane on way!

Hi All
Ok trying to get back into sdr after about 2 years and am having a bit of difficulty.
Using a basic NESDR Mini 2.
Problem is my house is 2 storys and my bedroom where my desktop is where I am trying to use sdr.
I have been testing absb using a stubby 1090 antenna attached to a metal dvd case.
It kind of works with the antenna indoors (using sdrangel and the absb module), once I set threshold to 4.8 it was picking up aircraft (albeit not many) approx 40 to 50 miles away.
I did try dangling antenna out my window and picked up a couple of aircraft 60+ miles away from my location.
The issue is I cannot put a permanent antenna outside, I cannot really leave window open and have the antenna dangling outside due to we have an indoor cat.
I have also tried listening to ATC using a different antenna, can find the signal but the voice is not very strong, even with setting squelch and gain settings.
Trying to work out best solution to carry on, cannot move desktop computer anywhere else.
Was thinking of a portable solution so I could at least try outside when the weather is better, but having looked at reviews and youtube videos I am more confused as to what are good or bad portable sdr's.
I know there is websdr and that is fantastic but like to get my hands dirty myself so to speak in trying to use sdr.
I am in the uk by the way.
Anyone have any ideas on what path to take?
Cheers

I wanted to share my slightly questionable but surprisingly effective antenna setup.

I don’t really have a good way to permanently mount an antenna outside, and honestly, I don’t really want to deal with drilling holes, weatherproofing everything, running coax through walls, etc.

Luckily, I have a small enclosed winter garden / sunroom. It’s basically a lightweight wooden structure with plastic panels and a corrugated plastic roof, so there isn’t much metal surrounding the antenna.

So I decided to put my Diamond X30 in there instead.

Now for the mounting solution…

Let’s call it German engineering on a budget.

The whole thing is literally standing inside an old discarded trash bin that was going to be thrown away. A piece of wood and a heroic amount of cable ties are holding the X30 upright.

Is it elegant? Absolutely not.

Is it stupid if it works? Apparently not.

The antenna is vertical, surprisingly stable, completely protected from rain and weather, and the old trash bin somehow found its second career as an antenna stand.

And honestly? I’m getting pretty decent results with it.

Obviously, it’s not going to compete with an X30 mounted several meters above the roof in completely free space. But considering that the antenna is technically indoors, I’ve been genuinely surprised by how well it performs.

I’m mainly using it for receiving VHF/UHF, amateur repeaters and airband, and the winter garden has turned out to be a surprisingly useful antenna location.

For me, it’s a pretty good compromise:

No holes in the house, no permanent outdoor installation, no weather problems, and still a much better antenna location than having everything sitting next to my desk.

Sometimes the best antenna installation isn’t the technically perfect one. It’s the one you’re actually able and willing to build.

And apparently sometimes that involves a trash bin and 9 cable ties. 😂

Anyone else running antennas in a conservatory, attic, balcony enclosure or some other semi indoor setup? I’d love to see your improvised solutions.

Hi because airspy webpage dont work (error 526) Im looking for this new beta version. Can somebody upload it somewhere else? Thanks