Tagged: FT8

SDR– Updated to V2.2: Many New Decoders, Tools and KrakenSDR Direction Finding and Beamforming Support Added

Last month we posted about the release of SDR-- (SDR minus minus), an open-source app that lets you visually wire together a receiver on a canvas. Since that time, Julian, the developer of SDR--, has been busy adding support for many decoders, various tools, and improving performance. Julian has also added KrakenSDR support, with radio direction-finding and beamforming blocks. Julian shares the following update for SDR-- V2.20:

New Decoders

  • Aviation and satellite: VDL2, HFDL, Inmarsat Aero and STD-C, Iridium, Drone Remote ID, 406 MHz beacons
  • Voice: TETRA, Tetrapol, GSM downlink, DECT, D-STAR, FreeDV, NXDN, dPMR
  • Data: LoRa (LoRaWAN, Meshtastic, MeshCore), ISM sensors, End-of-Train, DSC, BLE, Wi-Fi survey
  • Weather: NOAA APT, Meteor LRPT, WEFAX, radiosondes with landing forecast
  • Broadcast: DVB-T/T2, DVB-S2X, DAB packet mode, DRM with xHE-AAC

Coherent and mobile

  • Direction finding, beamforming and passive radar on the KrakenSDR
  • An iOS app with CarPlay for DF while driving is in TestFlight. Android is coming soon.

Hardware

  • Native Support: KrakenSDR, RTL-SDR Blog V4 Lite, AntSDR, PlutoSDR, SDRplay, Airspy, bladeRF and ESP-SDR
  • NanoVNA and antenna rotators
  • rtl_tcp and ADS-B Beast output for other apps

Tools

  • A satellite node with Doppler correction, plus a map with footprints and tracks
  • A spectrum monitor that classifies signals automatically, and a scanner with priorities and lockouts
  • Antenna calculator, noise figure, PER tester, SID monitor
  • Audio denoise, call recording, and a decoder log grouped by station
  • Event outputs: CSV, desktop notifications, PostgreSQL, InfluxDB

App

  • A redesigned UI with a unified look for every node
  • Multi-user editing, remote access from a browser, built-in HTTPS
  • An MCP server, so an AI assistant can build and tune a canvas

Performance

All measured on an M4 Max, full results at https://sdrmm.com/benchmarks:

  • DSP against GNU Radio:
  • FIR is 3.5x faster
  • NCO is 3x faster
  • FM demod is 4x faster
  • DDC is 1.6x faster
  • A 4096-point FFT is 1.6x faster than FFTW
  • Decoding rate in noise (48 trials per decoder across an SNR range):
  • ADS-B: 68%, against 56% for readsb and 50% for dump1090-fa
  • POCSAG: 73%, against 50% for multimon-ng
  • DMR: 81%, against 60% for dsd-fme
  • NXDN: 67%, against 23% for dsd-fme

(feel free to verify yourself with cargo xtask compare dsp)

The speed comes from hand-written SIMD kernels (NEON, AVX2, AVX-512), one shared downconversion for all channels on a radio, and a DSP path that never locks or allocates. The noise gains come from decoding IQ directly with
coherent receivers and soft decisions.

SDR-- Screenshot
SDR-- Screenshot

AI Disclaimer: This software is likely to be AI-assisted or vibe-coded.

HamRadioWeb FT8 WSJTx JTDX Remote Control Android App

Thank you to Patricio (LU5AKF) for sharing with us the release of HamRadioWeb.com's new FT8 WSJTx JTDX remote control Android app. Previously, we posted about HamRadioWeb's browser-based remote FT8 and FT4 receiver, and this Android app seems like a natural continuation of their software.

Patricio writes:

The app allows amateur radio operators to remotely control their JTDX or WSJT-X station from any Android phone or PC — no VPN, no port forwarding required.

What operators can do with it:

  • Monitor real-time FT8/FT4 decodes and band activity, just like sitting in front of JTDX or WSJT-X
  • Respond to CQ calls and transmit CQ remotely
  • Check where your signal is being heard via PSKReporter
  • Explore a worldwide activity map and a public DX spot page
  • Keep a contact log — auto-detected or manually added/imported
  • Follow community rankings and chat with other operators

The station connection is handled by a free Windows companion app (HamRadioWeb Companion) that links JTDX or WSJT-X to the user's account.

No radio at hand? The app opens in demo mode with simulated data so anyone can explore before creating an account.

Screenshots from the HamRadioWeb.com FT8 Remote Control App.
Screenshots from the HamRadioWeb.com FT8 Remote Control App.

SDR–: A Software-Defined Radio Application with Visual Signal Path

Thank you to Julian for writing in and sharing with us his interesting project called SDR-- (SDR minus minus). SDR-- is an open-source app that lets you wire devices, decoders, and displays together on a desktop window or browser-based canvas. It is described as "a software-defined radio application with a visual signal path. Connect devices, decoders, displays, and recorders on a canvas, then pin the controls you use to a rack."

A separate Rust server, which can sit on the same PC or a remote computer (like a Raspberry Pi), handles the DSP. Julian notes that SDR-- has native RTL-SDR support, and decoders for ADS-B, AIS, POCSAG, FT8, SSTV, and RDS are already implemented, with more in progress. The app also has a built-in signal generator and a repository of IQ recordings that can be used for experimentation and testing the various decoders.

The project releases are available on GitHub releases, and they cover Windows, Linux, and MacOS. 

SDR-- Screenshot
SDR-- Screenshot

HamRadioWeb: A Browser-Based Remote FT8/FT4 Receiver with Live Heatmaps, Performance Metrics and DX Cluster

Thank you to Patricio for writing in and sharing with us his release of HamRadioWeb, a browser-based remote receiver with a focus on FT8 and FT4 reception. If you're not aware, FT8 and FT4 are amateur radio digital fixed-format modes that can be decoded even with very weak signals. 

The software works by running a small server bridge app alongside JTDX/WSJT-X on the shack PC. Users can then log in from anywhere in the world on any device via the browser-based system. Once logged in, you can transmit and monitor, just as if you were sitting in a ham shack.

HamRadioWeb is designed to streamline remote FT8/FT4 operating directly from any mobile browser or PC without requiring complex setups like VPNs or port forwarding. In addition to remote TX/RX control, it features:

  • Live FT8 geospatial heatmaps and signal footprint visualization.
  • Grid-level SNR benchmarking against nearby stations.
  • Azimuthal radar & path telemetry relative to the shack.
  • Automated DXCC and award hunting synchronized with logbook data.

It’s built to make remote digital mode operating visual, data-driven, and easily accessible on the go.

HamRadioWeb is free for unlimited decodes, but limited to 10 TX's per day. Premium is a paid service costing $4.99 per month, which provides unlimited access.

HamRadioWeb: A Demo of the FT8/FT4 Terminal Display
HamRadioWeb: A Demo of the FT8/FT4 Terminal Display

TechMinds: Testing the SDR++ Brown Fork with Built-In DSD and Remote KiwiSDR Support

Over on YouTube, Matt from Tech Minds has uploaded a video in which he demonstrates and tests an unofficial fork of the popular SDR++ software called "SDR++ Brown."

SDR++ Brown has some unique features such as the ability to connect to remote KiwiSDR WebSDRs directly within the UI, built-in FT8 and FT4 decoders with PSK reporter, a built-in DSD decoder allowing for DMR, P25 and NXDN to be decoded directly in the software, Hermes Lite 2 support, and various Android UI improvements for small screens.

Matt also notes a few bugs with the software, such as PSK Reporter and Multi-WebSDR waterfall display features being broken.

Over on X, Alexandre Rouma, creator of the original SDR++, has expressed concern about this fork. He notes that this is an unofficial fork that is not up to his standards and that support requests for SDR++ Brown should not be made to him. Instead, support requests should be made directly to the fork owner, Sanny Sanoff.

SDR Plus Plus - Brown Edition Adds New Features Including DSD!

Testing the ATS25 Max-Decoder Receiver

Thank you for Manuel Lausmann for submitting his videos where he tests out and upgrades an ATS25 Max-decoder receiver. The ATS25 Max-decoder is a low cost portable HF receiver which has a large number of decoders built in such as RTTY, Hell, FT8 and FT4. Manuel notes that more decoders are still to come, such as SSTV. The built in decoders make it superior to it's predecessors the x1 and x2.

We note that the ATS25 Max appears to be around US$75 on Aliexpress, but these appear to be Max units without the "-decoder" add on. So if you are looking at purchasing one, please make sure to check that you are getting one with the text "max-decoder".

Manuel also notes that older models of the ATS25 can be retrofitted with a decoder PCB and converted into an ATS25 Max-decoder with a firmware update written by Bernhard Binns.

Note that Manuel's videos below are narrated in German, however the YouTube subtitle auto-translate feature works well enough to understand what is being said. In the first video Manuel demonstrates and reviews the ATS25 Max-Decoder, showing off some of the decoding features.

In the second video Manuel shows how to update an old model ATS25 in to the ATS25 Max by soldering on the decoder board.

Alter ATS25 umbauen zum max Decoder Teil 1 Die Hardware

Maverick-603 Project Suspended Indefinitely

Back in December 2022 we posted about the Maverick-603 which was at that stage Crowd Funding on Crowd Supply.

It was to be a US$149 FT8 receiver based on an open source RF chip design, capable of acquiring signals between 7 MHz and 70 MHz (technically 1 MHz to 100 MHz). Shipments were expected to begin in April 2023.

Unfortunately the Maverick team just released today that the project will be suspended indefinitely due to logistical issues. Backers of the project will receive a full refund.

The Maverick-603 project has been indefinitely suspended due to unforeseen logistical obstacles. No funds have yet been spent and all backers will receive full refunds. If you backed this project, your refund will be issued within the next week to the credit card you originally used. If your credit card is no longer valid, please contact Crowd Supply support before midnight UTC on Friday, April 28, 2023 to arrange your refund. If the Maverick-603 project is revived, we will post another update. Thank you for your support and patience.

The Maverick-603 FT8 Receiver
The Maverick-603 FT8 Receiver

Maverick-603: An Affordable FT8 Receiver with an Open Source RF Chip

The Maverick-603 is a US$149 FT8 receiver based on an open source RF chip design which is capable of acquiring signals between 7 MHz and 70 MHz (technically 1 MHz to 100 MHz). It is currently undergoing Crowd Funding on Crowd Supply with 7 days left in the campaign. Shipping is expected to begin in April 2023.

FT8 is a popular weak signal propagation digital mode used by ham radio enthusiasts. FT8 signals can be received and decoded all over the world even with low transmit power and poor propagation conditions thanks to its highly error tolerant encoding. A dedicated FT8 receiver allows enthusiasts to set up a 24/7 FT8 monitor without dedicating more expensive ham radio equipment to the task. Note that a computing device like a PC or possibly a Raspberry Pi 4 will still be required to run the FT8 decoding software as this is a software defined radio.

The Maverick-603 is based on a custom open source RF chip design made possible by the company eFabless. It is now possible to cheaply design and produce custom ASIC chips (at least at the lower end of the technology scale), replacing more costly FPGA designs. The technical specs of the Maverick-603 are:

  • MCU: ATMEGA1608
  • Power Supply: 3.3 V / 10 mA
  • Operating Frequency Range: 1 to 100 MHz
  • Minimum Signal Strength: -25 dBm
  • Input Antenna Impedance: 50 Ohm
  • Data Interface: SPI
  • Board Size: 2" x 1.75"
  • Capable of receiving FT8 signals
  • 7 - 70 MHZ frequency range
  • Low-power operation (1.8 Volts) means no battery or outlet is required
  • USB Connection
  • A compact surface area
The Maverick-603 FT8 Receiver
The Maverick-603 FT8 Receiver