Category: RTL-SDR

Manuel Compares the RTL-SDR Blog V3 vs RTL-SDR Blog V4

Not too long ago we released our first batch of RTL-SDR Blog V4 dongles, and most have been received by customers now. The next batch is coming soon, and we should be able to start sales again within the next 1-2 weeks from this post. It is incorrect rumors that they are totally sold out forever already. There should be sufficient stock for at least a year, so everyone who wants one will can get one.

In his latest YouTube video Manuel Lausmann compares the performance of the RTL-SDR Blog V3 and the RTL-SDR Blog V4. The video is narrated in German, however YouTube's autotranslate + captions feature works well.

In the video he first compares the performance on HF, noting that there are significantly less interference signals in the HF spectrum due to the lack of Nyquist folding around 14.4 MHz, which is a known problem with the direct sampling mode. He later also compares performance in the VHF and UHF bands, notably finding an improvement in the 145 MHz region where the V3 has a pumping noise floor from out of band interference, whereas the V4 does not thanks to it's additional filtering.

Der neue RTL SDR V4 VS RTL SDR V3

SatDump Version 1.1.0 Released – Feature Overview

SatDump is a popular program that can be used with RTL-SDRs and other software defined radios for decoding images from a wide array of weather imaging (and other) satellites including GOES, GK-2A, NOAA APT, NOAA HRPT, FengYun, Electro-L and Meteor M2 LRPT + HRPT, and many many others. It is multiplatform, running on Windows, MacOS, Linux and even Android. Because of it's good decoding performance, wide satellite and OS compatibility, it is the most recommended software for satellite decoding.

Recently SatDump was updated to version 1.1.0 and the new version brings many enhancements and new features. In summary, Lua scripting support has been added, calibrated products are now possible, composites can be made via Lua scripting, nightly builds are now available on GitHub, Mac .dmg builds are now available, decimation has been added, an SDR Server is available, and a Windows installer was added.

Support for various satellites and their instruments have also been added for NOAA APT, CCSDS LDPC decoding for Orion, LandSat-9, TUBIN X-Band, FengYun-3G/3F, Meteor M2-3, Geonetcast (soon), GOES RAW X-Band,  STEREO-A, DSCOVR EPIC, ELEKTRO-L N°4, Inmarsat STD-C, UmKA-1 (soon), PROBA-V GPS .

SatDump also now includes rotor tracking control which works together with it's satellite pass predictor and scheduler. There is no more need to use programs like Orbitron or Gpredict as everything can be handled by SatDump.

An insane amount of work has gone into SatDump, so if you like the software please remember to support the developer @aang23 by donating on Ko-Fi.

SatDump Rotator controller, Tracker and Scheduler

M2_LRPT_DECODER Version 59 Released

Thank you to Carl Reinemann for writing in and sharing with us that the Meteor M2 LRPT decoder by Oleg (Robonuka) was recently updated. The Russian Meteor M2-3 weather  satellite was launched in June of this year and is currently the only operational Meteor M2 satellite in the sky. It transmits images at 137 MHz in the digital LRPT format.

To receive it a simple V-Dipole antenna and RTL-SDR is usually sufficient. And to decode it software like SatDump or M2_LRPT_DECODER combined with the Meteor Demodulation Plugin for SDR# can be used. Instructions for the latter are available on HappySats instructional page.

Regarding the update Carl writes:

Thanks to Oleg (Robonuka), Happysat and Usradioguy have been testing the new decoder for about 6 weeks now, and it is ready to go!

  • The stability of the processing has been improved: The decoder is now more likely to produce stable results, even when there are errors in the input data.
  • The procedure for generating RGB and calculating GEO in the error-handling block has been improved. Now, the decoder's processing is considered unfinished until the GEO calculation is completed.: This means that the decoder will now wait until the GEO calculation is finished before generating the RGB values. This helps to prevent errors and produce more accurate results.

  • Exception errors fixed: Some errors that were previously causing the decoder to crash have been fixed.

  • AutoClose=yes by default: This means that the decoder will now automatically close when it is finished decoding. This can be helpful for saving resources and preventing memory leaks.

  • 80K is much more stable: The decoder is now more stable than before. This means that it is less likely to crash or produce unexpected results.

  • Overall, these changes make the decoder more reliable and easier to use.

    V59 Software can be downloaded from my page https://usradioguy.com/meteor-m2-3/ , or on happysats page

    Update instructions are on my page as well.
Screenshot of an older version of M2 LRPT Decoder
 

Recent Talks from the Society of Amateur Radio Astronomers 2023 Conference

Over on their YouTube channel there have been numerous talks uploaded over the past few months from the 2023 Society of Amateur Radio Astronomers (SARA) conference. Some of these talks are quite useful for beginner radio astronomers who are getting started with small dishes and software defined radios like the RTL-SDR.

One talk by Alex Pettit describes how to build a radio telescope from a an umbrella and some "Faraday fabric" which is copper cloth. The results show more than adequate performance for the cost, making this an affordable and easy entry to radio astronomy.

Alex Pettit - Umbrella Antennas

Another video presented by Dr. Wolfgang describes building small to medium sized radio telescopes. He explains how small radio telescopes less than 3 meters in size can work well for receiving the 21cm Hydrogen line, and how SDRs are the best choice of receiver for them. Many examples of small dish installations are shown.

Dr. Wolfgang Herrmann: Building Small/Medium Size Radio Telescopes

A Tape Measure Antenna for Receiving HF Numbers Stations

In his Hackaday.io post (and a post on the main Hackaday blog), Tom Farnell explains how he used two 10-meter tape measures combined with an RTL-SDR Blog V3 software defined radio to receive numbers stations in the HF bands. We want to add that this antenna isn't restricted to just numbers stations, and could receive many different types of shortwave and amateur stations on HF.

In his post Tom explains what numbers stations are and why they are interesting. In brief, a numbers station is a radio broadcast of a voice saying a bunch of numbers continuously. These stations are known to be espionage related, containing some sort of coded message for international spies to decode.

Tom goes on to show how the antenna is constructed. As HF antennas need to be long to get the best reception, Tom uses the long metal tape measure and attached it to the included dipole assembly that comes with the RTL-SDR to increase them to an appropriate length. 

Can You Pick Up Number Stations With A Tape Measure Antenna ?

TechMinds: Testing the RTL-SDR Blog V4

Over on his TechMinds YouTube channel Matt has uploaded a new video showing him testing out the new RTL-SDR Blog V4 dongle that we released a couple of weeks ago. In the video Matt explains the differences between the RTL-SDR Blog V3 and V4 dongles, and then goes on to show the Blog V4 dongle in action. He finishes by comparing reception between the V3 and V4, noting the reduced interference on the HF bands due to the lack of Nyquist folding from direct sampling.

We note that the first batch of the RTL-SDR Blog has currently sold out, but a new larger batch will be ready to go on sale around the end of September. So please keep an eye on the blog's main page and store if you are interested in picking one up.

RTL SDR V4 - Now with Built-In HF Upconverter + More Features

DragonOS: Decoding Train Telemetry with SoftEOT and RTL-SDR

Over on his YouTube channel Aaron who created and maintains the DragonOS SDR Linux distribution, has uploaded a video demonstrating how to use an RTL-SDR and SoftEOT/PyEOT to decode North American wireless train telemetry.

HOT (Head of Train), EOT (End of Train) and DPU (Distributed Power Unit) telemetry is sent from various parts of a train and contains information about things like voltages, brake line pressure and to monitor for accidental separation of the train.

In his video Aaron uses his DragonOS Linux distribution, SDR++ with an RTL-SDR Blog V4 dongle and the SoftEOT and SoftDPU decoders. SoftEOT and SoftDPU are both Windows programs, however Aaron shows how to use WINE to run them in Windows. Later he shows how to use an alterative decoder called PyEOT which is based on GNU Radio.

DragonOS FocalX Decoding Train Telemetry w/ SoftEOT/PyEOT (RTLSDR V4, WINE AppImage, GR 3.10)

Reminder: GNU Radio Conference 2023 Starts September 5 MST

This is a reminder that GNU Radio Conference 2023 (GRCon23) will be starting tomorrow on September 5 in Mountain Standard Time (MST) and will run until September 9.

GNU Radio conference talks are generally about cutting edge radio research topics and applications that involve the use of GNU Radio, a popular DSP framework for SDRs. If you are interested, previous years talks can be found on the GNU Radio YouTube channel.

The talks at GRCon23 will be livestreamed on YouTube for free, and we have pasted the links to each days live stream link below. We recommend activating YouTube notifications on each video so you won't miss the start.

There is also a virtual conference chat available. Links to the various rooms are available on the participants guide website.