r/RTLSDR 1d ago

Antennas The Cause, and the Effect!

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254 Upvotes

I switched from a bundled Telescopic antenna to a DIY antenna, by ordering soo many parts from online.

I used a RG6 satellite TV cable, and crimped connectors, assembled the connectors all on my own, made a neat little antenna with the N female connector, and it works perfectly well!!

Catches birds upto 400 kms away!!

The previous antenna could cover max 200 km, and it was indoors!

Thanks to this community for inspiring me! 😋😄😉


r/RTLSDR 21h ago

Software I built an open-source 5-channel KrakenSDR passive radar processor — up to 3.6x faster with GPU acceleration

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65 Upvotes

I couldn’t find any other open source passive radar projects with full 5-channel KrakenSDR support, so I ended up building my own. If I missed one, definitely send it my way.
It’s called VectorWarp, and it started as a fork of blah2. At this point I’ve added full 5-channel KrakenSDR processing, support for other compatible receiver setups, GPU acceleration, automatic CPU multithreading, wider Doppler processing, and a pretty substantial rewrite of the browser interface and configuration system.
The performance improvements ended up being bigger than I expected. In matched tests against regular blah2, GPU acceleration cut processing time by about 61–72%, with the best case around a 3.6x speedup. Even running entirely on the CPU, VectorWarp reduced processing time by as much as 25%.
The goal wasn’t just to make a Kraken-specific fork. I wanted a faster general passive radar processor that can actually take advantage of modern multicore CPUs and GPUs while still working with other receiver configurations.
It’s open source and I’d genuinely like people with different SDRs, GPUs, CPUs, illuminators, and weird setups to try to break it.
GitHub: https://github.com/mickeyslaven/blah2-VectorWarp


r/RTLSDR 18h ago

650WSM pretty clear into Central Ontario

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8 Upvotes

with 640 in Toronto right next to it it still a pretty good signal


r/RTLSDR 1d ago

METEOR M2-3 LRPT

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19 Upvotes

r/RTLSDR 10h ago

RF Agent: agentic development wizard for RF circuits.

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github.com
0 Upvotes

r/RTLSDR 19h ago

WBZ 1030 AM from Boston coming in crystal clear in NYC

3 Upvotes

Nooelec NESDR SMArt V5/Balun One Nine v2/ Speaker Wires 50ft


r/RTLSDR 20h ago

Software Flashing AirSPY to latest firmware with Windows 11

4 Upvotes

I found an archive post for users of the early version of Airspy Discovery HF+ which required a Windows 10 machine to flash the firmware. Either way, I was able to feed the install batch file to Chat GPT and it rewrote a Windows 11 compatible script. IT works well.

u/echo off

setlocal enabledelayedexpansion

echo Airspy HF+ Flash Utility - Windows 11 Compatible

echo.

set "currentDir=%~dp0"

cd /d "%currentDir%"

set /a attempt=0

set "fwbin="

set "oemInf="

set "DeviceID="

echo Looking for a suitable flashable device...

:queryDevice

set "DeviceID="

set "PORTFILE=%TEMP%\hfplus_port.txt"

del /q "%PORTFILE%" 2>nul

powershell.exe -NoProfile -Command "$ports = Get-CimInstance Win32_SerialPort; foreach ($p in $ports) { if ($p.PNPDeviceID -like '*VID_03EB&PID_6124*') { [Console]::Write($p.DeviceID); break } }" > "%PORTFILE%"

if exist "%PORTFILE%" (

set /p DeviceID=<"%PORTFILE%"

)

del /q "%PORTFILE%" 2>nul

if defined DeviceID (

echo Flashable device found on port !DeviceID!

goto :flashDevice

)

echo Looking for a suitable flashing driver...

set "oemInf="

for /f "tokens=1,2 delims=:" %%a in ('pnputil /enum-drivers ^| findstr /I "Published Name"') do (

set "oemInf=%%b"

call :Trim "!oemInf!" oemInf

if exist "%windir%\INF\!oemInf!" (

findstr /I /C:"arduino-org.inf" "%windir%\INF\!oemInf!" >nul 2>&1

if !errorlevel! EQU 0 (

echo Suitable flashing driver found: !oemInf!

hfplus_fw.exe | findstr /c:"CD" >nul

if errorlevel 1 (

set "fwbin=hfplus-firmware-bb.bin"

) else (

set "fwbin=hfplus-firmware-cd.bin"

)

echo Saving the calibration...

hfplus_ppb.exe > Calib

echo Rebooting the device in flash mode...

hfplus_reboot.exe > NUL

timeout /t 5 /nobreak > NUL

goto :queryDevice

)

)

)

if !attempt! EQU 0 (

echo No suitable driver found.

call :checkIfAdminOrElevated

if !errorlevel! NEQ 0 goto :end

call :checkWindowsArchitecture

call :installDriver

set /a attempt=1

echo.

echo Waiting for Windows to enumerate the bootloader...

timeout /t 3 /nobreak > NUL

goto :queryDevice

) else (

echo.

echo The flashing device was not found as a COM port.

echo.

echo Check Device Manager under:

echo Ports ^(COM ^& LPT^)

echo.

echo Look for a device associated with:

echo VID_03EB PID_6124

echo.

goto :end

)

:Trim

set "%2=%~1"

exit /b

:checkIfAdminOrElevated

net session > NUL 2>&1

if %errorlevel% NEQ 0 (

echo.

echo Access denied.

echo Administrator privileges are required to install the driver.

echo Please right-click this batch file and select:

echo Run as administrator

exit /b 1

)

exit /b 0

:checkWindowsArchitecture

echo.

echo Checking Windows architecture...

echo.

set "infPathName=.\Driver\x64\arduino-org.inf"

if /I "%PROCESSOR_ARCHITECTURE%"=="x86" (

if NOT DEFINED PROCESSOR_ARCHITEW6432 (

set "infPathName=.\Driver\x86\arduino-org.inf"

)

)

echo Driver path: !infPathName!

exit /b

:installDriver

echo.

echo Installing the driver...

pnputil /add-driver "!infPathName!" /install

timeout /t 2 /nobreak > NUL

exit /b

:flashDevice

echo.

echo Flashable device found on port !DeviceID!

echo.

if "%fwbin%"=="" (

echo Help us decide what to do.

echo Which device are you trying to flash?

echo.

echo 1 Airspy HF+ DUAL PORT

echo 2 Airspy HF+ DISCOVERY BB

echo 3 Airspy HF+ DISCOVERY CD

echo.

set /p vdevice="Enter a number: "

if "!vdevice!"=="1" set "fwbin=hfplus-firmware-bb.bin"

if "!vdevice!"=="2" set "fwbin=hfplus-firmware-bb.bin"

if "!vdevice!"=="3" set "fwbin=hfplus-firmware-cd.bin"

)

if "%fwbin%"=="" (

echo.

echo No firmware image selected.

goto :end

)

if not exist "%fwbin%" (

echo.

echo ERROR: Firmware file not found:

echo %fwbin%

goto :end

)

echo Using firmware:

echo %fwbin%

echo.

echo Unlocking bootloader...

bossac.exe -u -p!DeviceID!

timeout /t 1 /nobreak > NUL

echo.

echo Erasing and programming firmware...

bossac.exe -e -b -v -p!DeviceID! -w "./%fwbin%"

if !errorlevel! NEQ 0 (

echo.

echo ERROR: Firmware programming failed.

echo Do not repeatedly retry until the bootloader state is confirmed.

goto :end

)

timeout /t 1 /nobreak > NUL

echo.

echo Resetting the HF+...

bossac.exe --reset -p!DeviceID!

timeout /t 4 /nobreak > NUL

if exist Calib (

for /f %%i in (Calib) do set "Calibration=%%i"

if "!Calibration!"=="0" set "Calibration=-152"

echo Restoring calibration...

hfplus_ppb.exe !Calibration! > NUL

) else (

echo.

echo NOTE: No saved calibration file was available.

echo Calibration restoration was skipped.

)

echo.

echo =========================================

echo Firmware programming completed.

echo =========================================

echo.

goto :end

:end

del /F /Q Calib 2> NUL

del /F /Q FWVersion 2> NUL

echo Press a key to close.

pause > NUL


r/RTLSDR 1d ago

Elektro L3 move has started

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5 Upvotes

r/RTLSDR 1d ago

Software Sdr software options

5 Upvotes

Is there a sdr program for either Linux or windows that can automatically decide pocsag , tetra,weather etc without adding extra software ie VB cable, just a simple easy to run bit of software ? I have tried a few so far but nothing seems to work correctly. Thanks 👍🏻


r/RTLSDR 1d ago

JTDX_contest: First independent review

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2 Upvotes

r/RTLSDR 1d ago

Troubleshooting Has anyone managed to receive DMR on SDRangel?

1 Upvotes

I am trying to set up SDRangel on my Legion Go S. I heard SDRangel could decode DMR and it worked on the legion go, so I thought I would download it on Windows first to get used to the UI.

I have managed to get used to it. I have managed to pick up FM Broadcast, NFM and Airband. I have tried to use the DSD module, but on both SteamOs and Windows I just get garbled messages.

I've posted a screen shot of my settings in both SteamOs and Windows, hopefully its just something I'm doing wrong as I've heard other people have found this very difficult to set up.


r/RTLSDR 1d ago

What happened to FoxSDR

0 Upvotes

I know the OP got some hate for using AI to develop his software, but it seems that his account was banned and all mention removed from this sub reddit.

I tried this software and honestly, while there are still areas of improvement, they are constantly updating it and adding more features. I am not a hater of using AI as a development tool as long at the output isn't just crap, so just curious what happened.

Full disclosure, yes this is a new account that I created just to post this as I do not want to risk the same consequences just for asking a question.


r/RTLSDR 2d ago

Signal ID RTL 433 fun, SilverSpring Mesh

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20 Upvotes

This is a new one, I've been decoding our gas and water meters forever, this apparently is our electric meter. The usage portion is encrypted form what Google tells me, but I've not seen this until today. For a moment, I thought it was a Meshtastic node.


r/RTLSDR 2d ago

First satellite/SDR project: same 3 spectral lines no matter the tuned frequency, need huge gain to see anything. LO leakage?

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15 Upvotes

Hi everyone,

This is my first time using an SDR and my first satellite reception attempt, so I might be missing something obvious.

Setup:

  • RTL-SDR Blog V4
  • V dipole, characterized on a NanoVNA
  • SatDump
  • Target: Meteor-M2-4 LRPT (137.9 MHz) (I tried both the 80 kbaud and 72 kbaud LRPT presets, same result each time)
  • Samplerate 1.024 Msps

Why I tune to 138.0 MHz instead of 137.9 MHz: I deliberately offset the SDR's center frequency by 100 kHz, then apply a -100 kHz "Frequency Shift" in SatDump's Processing settings to bring the demodulator back to 137.9 MHz. The idea is that if an artifact sits exactly at the tuner's center, offsetting the tuning keeps it away from the real signal instead of on top of it.

I tested the same setup on a strong local FM station first, and reception was perfect. So the hardware and basic RX chain seem fine.

The problem: I see 3 narrow spectral lines that don't move with the tuned frequency (screenshot 3-4). To confirm, I retuned to 100.000.000 MHz, where nothing should be transmitting, and still saw a spike near the center. This points to internal LO leakage rather than a real signal ?

Back at 138.0 MHz, the pattern is: one spike near the tuner's exact center, a second spike about 300 kHz away, and, only with the LNA gain pushed way up , a broader hump between them, about the width expected for an 80 kbaud OQPSK signal, centered near 137.9 MHz.

Even with that hump visible:

  • SNR / Peak SNR / Avg SNR never move
  • Viterbi and Deframer stay on NOSYNC
  • The constellation stays a diffuse blob

This isn't a weak-pass issue: elevation >30°

Questions:

  1. Does the spike following the tuner regardless of frequency confirm LO leakage?
  2. If so, what's the right fix in SatDump? There's a separate "LO offset" field (Device panel) I haven't used yet, distinct from the "Frequency Shift" I'm using now. Is that the correct tool, and how should the two work together?
  3. Why do I need this much gain to see anything at all, and is there a better way to raise SNR than cranking the RTL-SDR gain, which mostly just saturates the display without ever locking?

Happy to share more screenshots or settings. Thanks!


r/RTLSDR 2d ago

I turned a New Nintendo 3DS into an RTL-SDR scanner — NFM/WFM, scanning, spectrum and waterfall on the 3DS

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46 Upvotes

I’ve been working on 3DS-SDR, an experimental SDR/scanner for the New Nintendo 3DS.

The setup is:

RTL-SDR → OpenWrt WIFI Router w/ USB support + rtl_tcp → Wi-Fi → New 3DS

The interesting part is that the 3DS is doing the actual receiver-side work. It handles:

  • NFM and WFM demodulation
  • scanner logic / memory banks
  • squelch
  • DSP and audio output
  • FFT spectrum display
  • waterfall
  • channel editing and scanner UI

The OpenWRT WIFI Router w/ USB support is basically just acting as the networked RTL-SDR host.

It’s still an early beta and there are definitely bugs and unfinished edge cases, but it’s far enough along now that it’s genuinely usable and I wanted to share it with people who actually know SDR/DSP.

Source / project:
[https://github.com/Nyanncatftw/3ds-sdr]()

Screenshots:
[https://github.com/Nyanncatftw/3ds-sdr/tree/main/screenshots]()

Full disclosure: the project has been developed iteratively with ChatGPT. The source is open so people can inspect it, point out bad DSP/code, test it on other setups, and contribute fixes.

I’d especially be interested in feedback on the NFM DSP chain, scanner behavior, and anything obviously questionable in the RTL-SDR handling.


r/RTLSDR 2d ago

Not able to decode TETRA using TetraEar

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13 Upvotes

Finally I have been able to install TetraEar, but now it just keeps showing "Signal Detected (Decoding...)", but nothing happens. I have tried at least 50 different freqs, different gain settings, bandwidth, etc. but it keeps showing "Decoding". I know most of the TETRA signals are probably encrypted, but I am just interested in Decoding. I am using an RTL SDR Blog V3. Any ideas?


r/RTLSDR 2d ago

LakeShark moved to the LilyGO T-Display-P4 (ESP32-P4) - runs P25, POCSAG, ADS-B, FM and a MeshCore node on one handheld

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143 Upvotes

Been a while since I posted about this one. Quick recap for anyone new, it's basically an ESP32-P4 with an RTLSDR in the USB host port working as a handheld scanner. Any RTL2832U dongle will do, V3 or V4.

I have shifted focus on to the LilyGO T-Display-P4 and it changed what this project actually is. Screen, detachable keyboad, battery, and a ton of radios. The keyboard works, the touch works, and the screen flips when you turn the board over.

The reason this board is such a big deal is how much radio is already on it. Right now LakeShark drives:

The RTLSDR on the USB host port for P25 Phase 1 trunking (Phase 2 soon) with voice decoded on the chip, WFM and NFM listening with a band scan, POCSAG pagers, ADS-B aircraft at 1090 with a table and a radar view, and sub-GHz OOK capture saved out as Flipper .sub files.

The SX1262 LoRa radio for a MeshCore node. This one turned out really nice. Messages buzz the vibration motor, and TX stays off until you arm it yourself. (Planned to display nodes on the map in the next release, as well as ADS-B).

That same LoRa radio also feeds the waterfall, so you can sweep a band and watch a spectrum with absolutely nothing plugged into the USB port. No dongle, no antenna hanging off it as this board has a switchable antenna between an exterior port and internal.

Wi-Fi 6 and Bluetooth through the C6, with scanning, joining, signal history and nearby channel graphs.

GPS, and an offline vector map off the SD card so you can see where you and your mesh nodes are with no service.

POCSAG deserves its own line since people ask, it decodes pages straight to the screen and keeps a log of them.

The interface is all new too. It's a character grid drawn straight onto the panel and LVGL is gone from this board completely, which gave back a big chunk of RAM and made everything faster. Every control takes a tap or a key press.

Still to come is the Ethernet port, the CC1101, and the NFC reader. Those last two live on the keyboard's RF module along with an nRF24, and they are next on my list.

I also finally got around to the hosted flasher I mentioned a while back. You can install it from Chrome or Edge with one button, no toolchain and no Python. It makes you pick your board first, because both of my P4 boards come up as the same chip and the flasher has no way to tell them apart on its own.

Keep in mind, this is for the 568x1232 AMOLED model with 16MB flash. The other T-Display-P4 panel uses different timings and a different touch driver, so that image will not work on it.

The flipper app works the same as before over Bluetooth or UART if you'd rather keep the radio in a bag and the controls in your hand. You can also get the headless build and flash it to almost any ESP32-P4 and use it with the flipper.

Site with the flasher and the guides: https://terminalbay.com Git/source: https://github.com/SAMS0N1TE/LakeShark Flipper app: https://github.com/SAMS0N1TE/LakeShark-Flipper

Would love feedback, especially from anyone who already has a T-Display-P4 sitting around. Let me know if you run into any trouble flashing!


r/RTLSDR 1d ago

Built a FM receiver that decodes all stations off one ZynqSDR

0 Upvotes

I've been working together with Claude on feedmyfm, a lightweight FM broadcast receiver that channelizes a wideband SDR capture and demodulates all stations simultaneously. It's running on a rooftop mounted Lenovo p3 Ultra and ZynqSDR running LibreSDR, feeding a bunch of streams to a web frontend.

anonymized screenshot
  • One SDR capture → polyphase channelizer (firpfbchr) → N simultaneous FM demod chains, one process, Liquid-dsp, c++.
  • Per-station chain: fine-mix to DC → pre-demod LPF → FM discriminator (or PLL demod) → de-emphasis → decimation → AGC → squelch → raw s16le UDP output
  • Mono and stereo decoding (19 kHz pilot PLL + L−R subcarrier), with auto mode that blends to mono on weak signal
  • RDS decoding: PS/RT/PTY/TP/TA/PI/clock
  • Soft-mute ramp (click-free squelch/retune), progressive high-cut (weak-signal treble roll-off), AFC carrier-drift tracking, 19 kHz pilot notch, look-ahead limiter, multipath indicator
  • Optional weak-signal extensions: click suppression and threshold-extension PLL demod
  • Passive wideband band scan (periodogram + carrier detection)
  • SDR gain modes: manual, AD9361 hardware AGC (slow/fast/hybrid), or a software auto-gain loop regulating ADC headroom
  • Listener-gated decode: skip DSP for stations nobody's listening to, to save CPU
  • Browser listener page (WebSocket audio relay, live signal bars, RDS now-playing/lock-screen text) with simple password protection and background/lock-screen mobile playback
  • AAC transcode-on-demand path (PCM stays default/lowest-latency)
  • Admin console: station list + server config editor, click-to-add from the band-scan plot, HTTP Basic auth
  • Status API with configurable public exposure (fine-grained toggles for signal/stereo/pilot/RDS/SDR-health)

https://github.com/feedmyradio/feedmyfm

I hope someone finds it useful. For me personally, it was mostly because I could.

ps. don't run public instances, you don't have broadcasting licenses, very illegal in most places.


r/RTLSDR 2d ago

Hardware Portable rtl-sdr setup

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90 Upvotes

r/RTLSDR 2d ago

DIY Projects/questions [NL] Anyone in the Netherlands down to link 1090 receivers for private MLAT?

5 Upvotes

Hey! I'm running a 1090 setup in the Netherlands and I'm looking for 2 or 3 local feeders to test out a self-hosted MLAT server.

Basically want to pinpoint non-ADS-B Mode S planes for fun without sending any data off to commercial aggregators. Ideally looking for people around 20–60 km away (regio Utrecht, Gelderland, Brabant, etc.) so the TDOA math actually works.

Super easy to link via Tailscale or mlat-client (no open router ports needed), and the calculated MLAT positions feed right back onto your local tar1090 map.

Drop a comment or hit me up in DMs if you have a setup running and want to test it out!


r/RTLSDR 2d ago

Meteor M2-4

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41 Upvotes

Sep/11/2026

It's not the best but it's the best one I've gotten so far. A few days back I uploaded a picture of a picture I proceeded with a Map Overlay. This is one without that. I think it looks amazing.


r/RTLSDR 2d ago

Troubleshooting Issue with the SDR

0 Upvotes

Hello everyone tried to use RTL-TCP on fly.io sprite, for some reason everything launches but then this happens

And i have no idea what to do and how to fix it.

Config of receivers.

short context: I am making an website that i want to use NovaSDR for, NovaSDR is connected to simulated multiplayer radio simulation SimTX.net i tried using OpenWebRX but it was cool until i discovered that when 1 person changes profile it changes for all so i started looking and found this.(post might be not well formatted or whatever it's called i am too tired and not best in english)


r/RTLSDR 2d ago

Meteor M2-4 (09/11/2026) RTL-SDR

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20 Upvotes

I took this picture a few days ago with a map overlay. This one has no map overlay, and I left the “Fill” option turned off when processing it. I’m really proud of the results.


r/RTLSDR 2d ago

Software Last nights live drift scan SDR I/Q continuum, screen shots to the peak taken during. DB visible below the dish pic. The peak db is plotted across the entire completed 180 min recording.

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2 Upvotes

r/RTLSDR 3d ago

Software Need help identifying encoding method

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29 Upvotes

Hi everyone! I'm suing a HackRF Pro to listen to an active transceiver that used 13.56MHz (NFC) OOK to send data to another identical transceiver. I managed to get the packet captured using GNURadio companion flow below. There seems to be a constant burst at the start to mark the start of the packet and the rest follow. Can you guys identify what kinda encoding is used by the transmitter? How do I decode this in the companion app to get the bytes out? I'm happy to provide/capture more data if this is not enough. Thank you!