Building a Transmit/Receive Relay System for a “Boat Anchor” Transmitter and SDRplay

Over on YouTube user ElPaso TubeAmps has uploaded a video showing his transit/receiver relay system that allows a "boat anchor" (old radio) ham radio transmitter and SDRplay SDR receiver to coexist. In order to protect the SDRplay's front end from being destroyed by a ham radio transmitting on the same antenna, a relay should be used to ground the SDRplay during a ham radio transmission. He writes:

How to build a small chassis and relay system to switch the antenna from the SDR input to ground and open the speaker connection from the PC to the speakers during transmit. I use "boat anchor", i.e. separate VFO for transmitter and receiver equipment and this video is about that type of connection and is not for transceivers.

SDRPlay, RTL-SDR, Transmit-Receive , PC Speaker, T/R Switch

SigintOS: A Linux Distro for Signal Intelligence

Recently we've heard of a new Linux distribution called SigintOS becoming available for download. SigintOS is an Ubuntu based distribution with a number of built in signal intelligence applications for software defined radios such as RTL-SDRs and other TX capable SDRs like the HackRF, bladeRF and USRP radios.

The distro appears to be very well executed, with a built in GUI that grants easy access to the some common sigint tools like an FM and GPS transmitter, a jammer, a GSM base station search tool and an IMSI catcher. SigintOS also has various other preinstalled programs such as GNU Radio, gr-gsm, YatesBTS, wireshark and GQRX.

The OS also teases an LTE search and LTE decoder which to access requires that you get in contact with the creators, presumably for a licencing fee. Regarding an LTE IMSI catcher they write:

LTE IMSI Catcher is not myth!

Due to the nature of LTE base stations, the capture of IMSI numbers seems impossible. LTE stations use GUTI to communicate with users instead of IMSI. The GUTI contains the temporary IMSI number called T-IMSI. This allows the operator to find out who is at the corresponding LTE station who is authorized to query T-IMSI information.

Can the GUTI number be found?
Answer Yes!

How to find GUTI and T-IMSI numbers?
Can be found with the help of SigintOS …

For detailed information [email protected]

The image comes as a 2GB ISO file, and it's possible to run it in WMWare or VirtualBox.

SIGINTOS IMSI Catcher
SigintOS IMSI Catcher

QIRX SDR Beta 2.0.1.0 Released: Improvements to DAB Scanner, Recorder and Spectra Display

QIRX SDR is a multimode SDR program compatible with the RTL-SDR. One of its defining features is that it has a built in DAB+ decoder. Recently beta version 2.01 of QIRX SDR was released which has some scanner, recording and spectra display improvements. We note that the beta version appears to be a DAB decoder only, with no multi-mode features. The new features and improvements include:

Scanner:

  • Configurable w/r to the Muxes to be scanned and/or included in the usual set of Muxes being used.
  • New algo, considerably faster
  • "Scan forever" feature, interesting for DX-ers wishing to observe Muxes over a longer time, particularly together with TII logging.
  • Selectable waiting time after recognition of a Mux, for TII logging.

Recorders:

  • TII Recorder: File structure improved, now directly importable into Excel, with TAB as separator.
  • Audio Recorder (DAB+ only): Format selectable between WAV (as usual) and pure AAC (with ADTS headers). The latter allows for high-quality recordings compressed by at least a factor of 10 compared to WAV. The popular Foobar2000 app is able to play these files. Not seekable yet though, because embedding in a suitable container is not yet implemented.

Spectra:

  • CIR with different scales (Samples, Distance, Time)
  • Indication of the correlation peaks used for the "FFT Window" determination in the CIR spectrum.
QIRX SDR Beta 2.0.1.0
QIRX SDR Beta 2.0.1.0
 

SignalsEverywhere: SDRAngel PlutoSDR Transmit Tutorial

Over on his YouTube channel SignalsEverywhere, Corrosive has uploaded a new video tutorial showing us how to transmit with a PlutoSDR and SDRAngel. His tutorial goes over the initial set up steps, selecting a modulator and changing modulator settings. He then goes on to demonstrate transmitting CW Morse code, using a CTCSS squelch tone and transmitting a Robot36 SSTV image via Virtual Audio Cable and MMSSTV.

SDRAngel Transmit Tutorial with PlutoSDR

Receiving Voice Communications From the Soyuz MS-12 Expedition to the ISS

On March 14 the Soyuz MS-12 spacecraft mission was launched and this carried three astronauts to the International Space Station (ISS). Back on the ground, YouTube creator Tysonpower was able to receive the voice communications of Russian cosmonaut Alexey Ovchinin while the Soyuz spacecraft was approaching the ISS. To do this he used an Airspy SDR and home made QFH antenna, and he notes that reception could just have easily been achieved with an RTL-SDR.

Tysonpower has uploaded a video explaining what he received along with a subtitled and translated recording of the communication. More information also available on his blog post.

[EN subs] Empfang von Cosmonaut Alexey Ovchinin im Soyuz MS-12

Conference Talk: Linux, Raspberry Pi, RTLSDR, LAME and Open Source (A Recipe For Responding to Natural Disasters)

The SCaLE conference on open source and free software was recently held on March 10 in Pasadena, California. One of the talks by Ben Kuo AI6YR was titled "Linux, Raspberry Pi, RTLSDR, LAME and Open Source (A Recipe For Responding to Natural Disasters)". This talk was streamed live, and is archived on YouTube.

In the talk Ben discusses how RTL-SDR's can be useful in disaster response by putting radio communications onto online audio streaming sites like Broadcastify. He notes how difficult it was for residents affected by the California wildfires to get up to date information on how close the fire was to their house from news stations and authorities. In contrast information on the internet came in much faster and more accurately. He notes in particular how listening in to firefighter radio communications via online streams uploaded by RTL-SDR users can give the fastest and most up to date information to concerned residents.

Ben also mentions how it can also useful to track the movement of fires via the ADS-B flight tracking data transmitted by fire fighting aircraft. By watching the aircraft movements the spread of the fire can be determined.

In the YouTube video stream, Ben's talk starts at about 3:31:00 and the video below should start at that time. The three other talks recorded in this stream are all ham radio related and may also be of interest to you.

Room 212 Sunday Mar. 10 - SCaLE 17x

A Vacuum Tube Based Shortwave Software Defined Radio

Vacuum tubes are not typically found in software defined radios, but this interesting mix of old and new technology by Mirko Pavelski uses one in it's front end. The way it works is that the analogue radio circuit receives a small range of spectrum, and then the tube acts as a mixer, converting that spectrum down into audio frequency range which can be heard by a computer sound card.

The sound card acts as the ADC, digitizing the signal, and then the "SDRadio" software performs the final filtering and demodulation of a narrowband signal in software. This is the same concept used by other HF sound card SDRs such as the Softrock, although those of course do not use tubes in their design. Mirko writes:

Simple to build receiver made according to the instructions of Burkhard Kainka : http://www.b-kainka.de/bastel100.htm. I made it with EF80 tube instead EL95 and it works great. It is powered by a 7.4V lithium-ion battery followed by a 7806 stabilizer, so we get 6v for tube heating and there are no problems with 50 Hz hum. Тhe resonant circuit is made of strong coil with 20 turns of 1.5 mm thick wire wound on a PVC tube with 18 mm diameter. At the cold end of the resonant circuit is an antenna coil with two turns. At the output of the radio, I connecт 2 transistor preamplifier and cheap amplifier module in D class. So we get battery powered tube АМ radio. Using the potentiometer we can select between AM or SDR mode of operation.

In SDR mode, we need to connect the output of the radio to "line in" in sound card of the computer. Then we use some of the free software for example "SDRadio" from Alberto I2PHD. Тhe receiver has very good frequency stability which drifts less than 1 Hz per minute. Тhis is important if we want to decode DRM signals. In good HF propagation conditions I receive BBC World service DRM radio (3995MHz) with 16dB SNR here in Ohrid (41.1231° N, 20.8016° E). This little radio, with a long wire antenna and good grounding, gives us a lot of fun.

Hackaday also recently posted an article about this build.

DIY one tube shortwave + SDR radio

SDRplay Release SDRUno V1.3 – Now with Frequency Scanning Feature

SDRplay have just released a major upgrade to SDRUno, the official software for SDRplay RSP software defined radios. Along with various bug fixes, the most interesting new feature in version 1.3 is the frequency scanner. This allows SDRuno to automatically tune to active signals between a set frequency range. SDRplay writes:

Major new features include:

Frequency Scanning (for both frequency ranges and stored memory panel lists)

I/Q → Audio Output (for CW Skimmer for example)

A new configurable IF AGC scheme

For a full list of additions/changes and bug fixes, please see the release notes at: https://www.sdrplay.com/docs/SDRplay_SDRuno_Release_Notes.pdf

This release of SDRuno uses a new version of the Windows Service based API (3.02) and so users that also used other applications such as dump1090 and HDSDR with the previous version of the Windows Service based API (3.01) will need to download and install the latest versions of API, dump1090 and the ExtIO plugin from our website at https://www.sdrplay.com/downloads

We have produced two new video guides which describe the use of the Frequency Scanner and I/Q Output functions. Links to these videos along with many others can be found by going to the SDRplay Applications and support catalogue on https://www.sdrplay.com/apps-catalogue/  , and on our Youtube Channel on https://www.youtube.com/c/SDRplayRSP

However, the two new videos can be viewed directly by going to:  

https://youtu.be/ndMWIK1JLbQ (New Features in SDRuno 1.3 - Scanning and AGC)

https://youtu.be/w_pH56aOdE0   (SDRuno IQ output and CW Skimmer guide)

Using the new integrated SDRuno Frequency Scanner:   https://youtu.be/ndMWIK1JLbQ (This video also covers the new IF AGC scheme)

Using SDRuno with CW Skimmer via the I/Q Output function:  https://youtu.be/w_pH56aOdE0

The ExtIO version of SDRuno can still be downloaded from our downloads page and is included in the SDRuno 1.22 release. Make sure to install it in a different directory to 1.3 otherwise it will stop 1.3 from working.

For any questions  or help regarding this new release, please contact SDRplay support via our dedicated support system at: https://www.sdrplay.com/support

For any other suggestions, please email [email protected]

Finally, we recommend that all users join our community forum where there is a wealth of knowledge and help available for using our products and software in a wide range of applications and circumstances. This forum can be found at: https://www.sdrplay.com/community

New Features in SDRuno 1.3: Scanning and AGC