Tagged: SSTV

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

IC-SDR: A New Multimode SDR Software for Windows Written in Go

Thank you to Luis Lopez Martinez for writing in and sharing the release of his open-source software, IC-SDR, a new multi-mode SDR application for Windows written in Gowith a focus on performance and efficiency. Luis writes:

IC-SDR supports AM, NFM, WFM, LSB and USB demodulation, along with several integrated digital decoders:

  • AIS
  • ADS-B (1090 MHz and UAT 978 MHz)
  • Radiosondes
  • APRS
  • RTL_433
  • DMR
  • SSTV
  • TETRA

It also includes a memory bank, real-time spectrum and waterfall displays, an audio recorder with automatic silence removal, and a frequency-segment scanner with instant triggering.

The Windows release can be found on the project's GitHub Releases page.

SDROxide: A New SDR Client for HAMs and SWLs written in Rust

Thank you to Josef (OE3JJS) for writing in and sharing with us the release of his new open-source software called SDROxide, an SDR client designed for HAMs and SWLs (short-wave listeners), written in Rust. The software supports Linux, Windows, macOS, and also has a web client. As it supports SoapySDR, RTL-SDR dongles are supported for RX. Josef writes about SDROxide:

It's a completely new project written in Rust, supporting many SDR interfaces (CAT/Audio, CAT/IQ, SoapySDR, HPSDR, TCI) and with loads of features built in that used to require extra programs: FT8/FT4, SSTV, RTTY, PSK, OLIVIA, THOR, FSQ, a CW/RTTY/PSK skimmer, there's dx cluster and sota/pota spotting, a logbook with integrations for QRZ.com, HamQTH, eQSL, LoTW, there's neural-network noise reduction, a 3D "hamclock" that visualizes QSOs, satellites, Aurora, CME cones, with up-to-date images of the sun's surface, and you can run the client locally, remote with native binary, or remote via the web (WASM).

Josef notes that the project is fully open-source and available on GitHub.

SDROxide: SSB Workspace
SDROxide: SSB Workspace
SDROxide: FT8 Workspace
SDROxide: FT8 Workspace

AI-Disclaimer: The author notes the use of local and hosted LLMs in the development of this software.

Decoding SSTV Transmissions from the QO-100 Satellite

Over on his YouTube channel dereksgc has uploaded a video showing how to decode Slow Scan Television (SSTV) transmissions from the QO-100 satellite. QO-100 is a commercial geostationary communications satellite available in some parts of the world that also carries a popular transponder for amateur radio. SSTV is an amateur radio communications analog protocol for transmitting images over a narrowband RF signal.

In the video dereksgc shows how to use SDR Console V3 together with a program like MMSSTV for decoding the image. He goes on to discuss the specific SSTV frequencies on QO-100, the different SSTV modes, and some demonstrations of images being received.

Decoding SSTV transmissions from the QO-100 satellite (QO-100 pt.2)

Receiving SSTV From the Russian UmKA-1/RS40S Cubesat

YouTuber 'saveitforparts' was recently contacted by the ground controller of the Russian UmKA-1/RS40S cubesat asking if he'd like to try and receive an SSTV image from the satellite. UmKA-1/RS40S is a small educational satellite assembled by a Russian high school. Originally it was intended for a radio astronomy experiment, but due to technical issues it's been switched to the secondary ham radio mission only.

Saveitforparts uses an RTL-SDR, directional Yagu antenna, PC running the MMSSTV decoder, and Android phone running the Stellarium satellite tracking app. After a few failed attempts he was able to eventually successfully track and receive the SSTV image as well as some telemetry.

We note that the SSTV image appears to have been specifically scheduled for saveitforparts personally, so if you try to receive this satellite yourself you will probably only be able to receive the telemetry signal.

Receiving Targeted Message From Russian Satellite

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

Using an RTL-SDR Dongle to Receive Pictures from the ISS

Over on YouTube we've seen a good video from channel Ham Radio DX where presenter Hayden shows how to use an RTL-SDR to receive slow scan television (SSTV) images from the International Space Station (ISS). Often the ISS will transmit SSTV images down to earth on the VHF 2 meter bands as part of an event. With an RTL-SDR and simple antenna it's possible to receive those images.

In the video Hayden discusses the SSTV transmission, and demonstrates some SSTV decoding happening in real time as the ISS passes over his location. If you're looking to get started in ISS SSTV reception, this is a good video to get an idea of what's involved. He finishes the video with some useful tips for reception.

Using a RTL SDR Dongle to receive pictures from the ISS! | Software Defined Radio

SSTV from the International Space Station Scheduled for Dec 24 – Dec 31

Thank you to Maksim for submitting news that the International Space Station (ISS) will be transmitting Slow Scan TV (SSTV) in late December to celebrate 20 years of amateur radio operations onboard the space station. The ISS periodically transmits SSTV images during special events throughout the year. You can keep up to date on the ISS SSTV schedule on the ARISS-SSTV site.

An ARISS Slow Scan TV (SSTV) event is scheduled from the International Space Station (ISS) for late December. This will be a special SSTV event to celebrate the 20th anniversary of ARISS operations on the ISS. The event is scheduled to begin on December 24 and continue through December 31. Details to follow later. Dates are subject to change due to ISS operational adjustments.

With an RTL-SDR and a simple V-Dipole from our RTL-SDR Blog V3 antenna kit it is possible to receive these images when the ISS passes over. ISS passes for your city can be determined online, and the SSTV images can be decoded with a program like MMSSTV.

An example SSTV image from the last ISS SSTV event
An example SSTV image from an SSTV event held in previous years.