Tagged: sdr#

Reducing HF Electrical Noise by Using a Faraday Cage for Switch-Mode Power Supplies

Over on his blog, DXer OH2-2192 was frustrated by lots of local electrical noise showing up on the HF bands on his Airspy + Spyverter SDR receiver. He discovered that the majority of the noise he was seeing was coming from the switch mode power supplies that power the electronic devices used in his setup. Switch mode power supplies are very common in the modern world, with almost every electronic device using one to efficiently convert wall AC into DC power. However, they convert power by rapidly switching on and off, and these on/off square wave pulses cause a lot of RF noise especially on the HF spectrum.

Instead of changing to noise free linear regulators which are expensive, very heavy and big, OH2-2192 decided that he'd try creating a Faraday cage shield out of metal mesh to enclose all his switch-mode power supplies. Using a simple AM loop antenna and Airspy's Spectrum Spy software he measured the amount of noise produced by a switch-mode supply placed inside and outside of the cage. The results he saw were very promising with the shielded supply eliminating the noise almost entirely.

Faraday Cage Shield for Switch Mode Power Supplies
Faraday Cage Shield for Switch Mode Power Supplies (Right image shows the results of a switching supply placed outside and inside the Faraday cage)

SignalsEverywhere PlutoSDR Videos: Applying the Frequency Extension and Dual Core CPU Hacks and Running on SDR#

Over on the SignalsEverywhere YouTube channel, Corrosive has uploaded two new videos about the PlutoSDR. The PlutoSDR is a low cost (typically $99 - $149) RX/TX capable SDR with up to 56 MHz of bandwidth and 70 MHz to 6 GHz frequency range. It also has an onboard FPGA and ARM Cortex-A9 CPU.

By default the bandwidth and frequency range of the PlutoSDR is limited to only 20 MHz and 325 MHz - 3.8 GHz. A minor hack which requires some commands to be input via a terminal screen is required to unlock its full potential, and in the first video Corrosive runs through how this hack can be applied. He also shows an additional hack which unlocks a second CPU core which can be useful for increasing the available CPU power for apps running on the PlutoSDR's ARM processor.

In the second video Corrosive shows how to install the PlutoSDR SDR# plugin, which allows the PlutoSDR to run in SDR#. He then shows how to actually use the plugin to connect to the PlutoSDR.

Adalm Pluto SDR Tutorial: 70Mhz to 6Ghz and Dual Core CPU Modification

Adalm Pluto SDR Sharp Plugin Tutorial ~ [Infamous SDR# on Your Pluto]

Running SDR# in a Windows Virtual Machine on Linux

Thanks to John Jackson of JRMagnetics for writing in and letting us know about his post on installing SDR# onto a Windows Virtual Machine (VM) running on Fedora Linux.

As John notes, running SDR software from within a virtual machine essentially freezes a working version of your setup in a virtual image. It's then possible to put the image on a memory stick and take your entire working software setup with you and run it on another PC. Using a fixed image then also avoids problems with OS updates breaking things, as updates can be safely turned off on the virtual machine. Any damage from viruses is localized to the virtual machine only.

During his research John found many people who have been running Linux from within a virtual machine running on Windows, but not the reverse. Originally he tried running a Windows VM from within Windows, but he experienced crashes. Only when using Linux as the base OS was his Windows VM stable.

In his setup he runs Fedora 26 as the base Linux OS (although other Linux versions should also work), and Windows 7 in the Virtual Machine. He uses Oracle VirtualBox as the virtualization software. Once Windows 7 is installed on the Virtual Machine, setting up software like SDR# is as simple as going through our quickstart guide.

SDR# Running in a Windows Virtual Machine
SDR# Running in a Windows Virtual Machine

New SDR# Plugin Adds Support for Contour Shuttle USB Controllers

Contour ShuttlePro V2
Contour ShuttlePro V2

The Contour Shuttle Express and Pro V2 are USB controller accessories for PCs. They consist of a knob-like wheel with multiple buttons and they are designed as a keyboard replacement for improving the productivity of video/photo editors. However, several people have found them useful for controlling software defined radio receiver programs like SDR#.

Recently SDR# plugin developer Eddie Mac has released a new SDR# plugin that provides native support for the Shuttle devices from within SDR# itself. The plugin allows you to dynamically map the Shuttle's buttons and wheels to functions within SDR#.

Eddie also writes:

There was no wrapper available for Contours Windows SDK so I created a managed .NET wrapper around contours dll. If anyone wants to develop their own software for these devices I will happily provide them with my .NET wrapper for free as well as a demo app to instruct on its usage.

Contour Shuttle Plugin for SDR#
Contour Shuttle Plugin for SDR#

Using an Airspy HF+ with SDR# and WSJT-X to Decode FT8 + SpyServer FT8 Decoding Demo

Over on YouTube user TheGazLab has uploaded a video that reviews the Airspy HF+, and also shows how to use the HF+ with SDR# and WSJT-X in order to create a FT8 monitor. The Airspy HF+ is high dynamic range HF/VHF receiver designed for DXing.

In the video TheGazLab demonstrates to us the decoding in real time, and explains the CAT control SDR# plugin that he's using. The CAT control plugin when combined with a virtual serial port driver allows the WSJT-X program to automatically tune SDR# to the FT8 frequency selected in WSJT-X.

Later in the video he also discusses the SpyServer network which allows SDR# users to connect to remote public Airspy and RTL-SDR units over the internet. He demonstrates connecting to a public server in the UK, and decoding FT8 via the remote server. The video also shows the new SpyServer interface by  which nicely lays out the world SpyServer network on a map, making it easy to choose a desired location to listen to.

Airspy HFPlus, SDR# and WSJT-X with full CAT control decoding FT-8

SDR# TETRA Plugin Now Available At RTL-SDR.RU

Vasilli has recently released the SDR# TETRA plugin on his website RTL-SDR.RU (note that the site is in Russian, but can be translated with the Google Translate option in the top right of the page). Previously it was only available via ever changing forum links, so it's good to see that it has a permanent home now for the latest version. This plugin allows you to listen to TETRA digital voice via SDR#, without needing to set up any complicated GNU Radio based receivers which were necessary in the past.

The features include (note Translated from Russian):

  • Receiving a signal from the BS band 25kHz and modulation Pi / 4-DQPSK;
  • Automatic adjustment of the reception frequency;
  • Displays information about the BS;
  • Displays ISSI, GSSI subscribers in the channels (for open channels only);
  • Displays a service exchange network (for open channels only);
  • It allows you to listen to the channels in manual or automatic mode selection (only open channels);
  • It allows to filter and distribute the listening priority specified for groups (GSSI);
  • It displays a message with the location (just a short message format)

The current features not yet implemented are:

  • And listen to correctly display any encoded information in a network;
  • Display SDS type 4 (short messages);
  • Record audio from the channels (menu added, but does not work);

We also note that as discussed in a previous post there is a companion program for this plugin called TETRA Trunk Tracker.

SDR# TETRA Decoder Plugin
SDR# TETRA Decoder Plugin

SDR# Physical Remote Now For Sale + YouTube Review

Back in August Maxim who runs his small company "ExpElectroLab" wrote in and shared with us news of his upcoming product called "SDR-Remote" which is a physical tuning knob and control panel for SDR#.

Recently the product was released for sale on his shop, and costs $57.50 USD + shipping. The vk.com store is for Russian customers only, but you contact him at [email protected] if you are non-Russian and are interested in his products. The features of the SDR-Remote are pasted below:

The heart is ARDUINO NANO V3.0, buttons, encoder and software.

Implemented by:

  • tuning the frequency of reception with frequency of 1 kHz, 100 kHz, 1 MHz (additionally 50 Hz)
  • volume control
  • mute
  • FM mono / stereo switching
  • switching modulation types
  • on / off noise control
  • Noise level threshold adjustment
  • adjustment of width of a strip
  • switching bands 160m, 80m, 40m, 25m, 13m.10m, FM, AVIA, 2m, 70cm

Maxim hand builds these in his home country of Russia, and has noted that since the case is 3D printed he can only create a few per week at the moment. The knob interfaces with SDR# via an Arduino driver and SDR# plugin which can be downloaded.

SDR-Remote V2.1
SDR-Remote V2.1

Over on YouTube a Russian reviewer has uploaded a video showing SDR-Remote v2.1 in action. The video is narrated in Russian, but YouTube auto-captions combined with auto-translate does a decent job.

Пульт для SDR-приёмника и SDRSharp.

An Introduction to SDR and SDR Applications for Shortwave Listeners

Over on the SWLing Post blog, author Thomas Witherspoon K4SWL has uploaded a new article titled "Software Defined Radio Primer Part 1: Introduction to SDRs and SDR applications". The article originally appeared in the June 2018 issue of The Spectrum Monitor magazine, which can be purchased online for $3 per issue.

The idea behind the article is to introduce people to SDR from a shortwave listening point of view, so high performance HF SDRs like the Airspy HF+, Elad FDM-S2 and WinRadio Excalibur are discussed. Thomas notes that these SDRs can perform as well as traditional DX-grade receivers that can cost two to three times more. He also explains what advantages SDR's bring to the shortwave radio listening hobby. This may be a good article to show those still using older hardware radios that haven't yet converted to the SDR world. 

The article is currently part one of a three part series, with parts two and three to be released in October and November.

DXing with SDR in a Car
DXing with SDR in a Car (Photo: Guy Atkins)