Category: Applications

NanoVNASaver Software Walkthrough + NanoVNA Firmware Updates Bring 1.5 GHz Max Range

The NanoVNA is an open source VNA project by @edy555 and ttrftech that has recently become extremely affordable at less than US$50 for a fully assembled unit thanks to Chinese manufacturing (or a little more if you order it via Amazon).

Ohan Smit had recently been playing with the NanoVNA and came across a software package from Rune B. Broberg (5Q5R) called NanoVNASaver. NanoVNASaver is an open source program that can be used to read and plot data from the NanoVNA. It has some nice features like the ability to display multiple charts, increase the resolution up to 10k points, measure cable length via TDR calculations, save Touchstone files and more.

Over on his blog, Ohan has put up a walkthrough guide about using NanoVNASaver. He shows how to setup the application, calibrate the NanoVNA, and then demonstrates how to use NanoVNASaver to measure the response of some filters.

Testing our RTL-SDR.COM BCFM Bandstop filter with a NanoVNA and the NanoVNASaver Software.
Testing our RTL-SDR.COM BCFM Bandstop filter with a NanoVNA and the NanoVNASaver Software.

Later in the same post Ohan also includes an update about his experiments with some new experimental NanoVNA firmware that extends the maximum frequency range from the previous maximum of 900 MHz up to 1500 MHz. Results show that while it can work up to 1500 MHz, accuracy rapidly degrades above 900 MHz.

 

TV Scrambling With GNU Radio and a FL2K Adapter

[mrgriscomredux] over on [Reddit] was interested in re-creating the nostalgia that was scrambled analog television from the 90s. To do this he captured an NTSC analog video signal using an RSP1 SDR and demodulated that into composite video using GNU Radio to process everything.

The methods that were originally used to scramble analog television are not well documented, however [mrgriscomredux] has done a fine job re-creating it himself in his own way.

He then uses a Python script to modify the “Gated Sync Suppression” within GNU Radio and then transmits that back on to the air using a low cost FL2K VGA adapter we’ve featured on the blog in the past.

These FL2K VGA adapters can be abused as crude software-defined transmitters and we’ve seen people do everything from video transmission to GPS spoofing with them. [Check out the FL2K article here]

broadcasting my own scrambled tv channel with SDR

SDRSharp Community Plugin Package Now Available

The SDR# developer in conjunction with Rodrigo Pérez have recently endorsed and released a "community plugin package" over on the SDR# downloads page. This consists of a SDR# installer that automatically downloads and installs a whole plethora of SDR# plugins.

In addition to the plugins it also automatically installs the RTL-SDR drivers, and the RTL-SDR (R820T) special interface which has the ability to use decimation and has individual controls for each of the three gain stages. You can also use it to automatically install the LimeSDR and PlutoSDR interfaces.

The .exe is a simple installer and you can select what plugins you want during the install. The installer automatically puts the SDRSharp folder in the C: drive.

SDRSharp Community Plugin Package
SDRSharp Community Plugin Package

The plugins included are:

  • Base Windows SDR Software Package (same as above)
  • Plugin Audio Processor
  • Plugin Audio Recorder
  • Plugin AUX VFO
  • Plugin Avia band 8.33 calculator
  • Plugin Baseband Recorder
  • Plugin Calico CAT
  • Plugin CTCSS decoder squelch
  • Plugin DCS decoder squelch
  • Plugin DDE Tracker
  • Plugin Digital Audio Processor
  • Plugin DSDtcp
  • Plugin File Player
  • Plugin Frequency Lock
  • Plugin Frequency Manager
  • Plugin Frequency Scanner
  • Plugin Gpredict Connector
  • Plugin IF Processor
  • Plugin IF Recorder
  • Plugin Level Meter
  • Plugin LimeSDR
  • Plugin Meteor Demodulator
  • Plugin MPX Output
  • Plugin PAL/Secam TV
  • Plugin Pluto SDR
  • Plugin RTL-SDR 820T
  • Plugin SDRSharp Net Remote
  • Plugin Time Shift

A Wall Mounted SatNOGS Ground Station Monitor

If you weren't already aware,  SatNOGS is an open source project that aims to make it easy for volunteers to build and run RF ground stations (typically based on RTL-SDR hardware) that automatically monitor satellite data, and upload that data to the internet for public access. This is very useful for low budget cubesats launched by schools/small organizations that don't have the resources for a worldwide monitoring network as data can be collected from all over the world no matter where the satellite is.

Over on the SatNOGS Libre Space forums, user cshields have posted about his near wall mounted SatNOGS monitoring station. With the station he's able to monitor the status of his SatNOGS station via an LCD screen and see the location of satellites that next in the queue to be received. There are also some status lights and LCD text screen for monitoring the SatNOGS rotator hardware.

The station consists of a Raspberry Pi 4, 7" LCD display, 500 GB SSD, RTL-SDR Blog V3, and an Arduino with 16x2 LCD and NeoPixel. cshields post covers the full details of the build.

[Also seen on Hackaday]

SatNOGS Ground Station Monitor
SatNOGS Ground Station Monitor

Hacking Iridium Satellites With Iridium Toolkit

Over on YouTube TechMinds has uploaded a video showing how to use the Iridium Toolkit software to receive data and audio from Iridium satellites with an Airspy. Iridium is a global satellite service that provides various services such as global paging, satellite phones, tracking and fleet management services, as well as services for emergency, aircraft, maritime and covert operations too. It consists of multiple low earth orbit satellites where there is at least one visible in the sky at any point in time, at most locations on the Earth.

The frequencies used by the older generation Iridium satellites are in the L-band, and the data is completely unencrypted. That allows anyone with an RTL-SDR or other SDR radio to decode the data with the open source Iridium Toolkit. If you're interested in how Iridium Toolkit was developed, see this previous post about Stefan "Sec" Zehl and Schneider's 2016 talk.

In the video Tech Minds shows decoding of various data, including an audio call and the satellite tracks and heat map of Iridium satellites.

Hacking Iridium Satellites With Iridium Toolkit

SignalsEverywhere: Harold’s Mobile SDR Vehicle Load Out for Amateur Radio

This week on the SignalsEverywhere YouTube channel Harold shows us the mobile SDR and ham radio setup that he's installed on his car. On the roof of his car he's installed several antennas for various amateur radio bands including the 1.25m, 2m, 70cm, 33cm bands, a modified GPS puck antenna for Inmarsat and Iridium reception, and an antenna and GPS pick dedicated for APRS.

Inside the vehicle is a Windows tablet attached to the dashboard which is used for APRS, remotely controlling a scanner radio stored in the trunk and for running SDRSharp. There is also an Android unit installed in the center console which has an RTL-SDR connected. The Android unit runs RF Analyzer, and an ADS-B decoder. As well as SDRs, Harold also runs several standard ham radios within the vehicle.

Amateur Radio Mobile SDR Load Out | SDR Plus 33cm 70cm 2m 1.25m and more!

Decoding PAL Video from a Nintendo with An Airspy SDR Part 2

Oona combines composite output for color images.
Oona combines composite output for color images.

Last week we posted about Oona Räisänen's ([Windytan] and @windyoona) project to capture live video from her 1985 Nintendo Entertainment System (NES) using an Airspy SDR. In order to avoid expensive Video Capture cards which didn't work on her Mac, she used an Airspy SDR to decode the PAL composite video output of the NES. Last week she had black and white video working.

This week she has full color working, and has on her blog posted a write up about her project with the Airspy and her experiences with trying to find a suitable capture solution. She also goes into some detail about the CPU performance considerations of this solution, noting that there are some performance bottlenecks. She's also uploaded a video showing the results in action.

MacBook decodes PAL video via SDR

Automatically Photographing Passing Aircraft with an RTL-SDR, Pi 3, and IoT Software

Arun Venkataswamy has recently completed a write up about his system which automatically captures images of passing aircraft. It works by using a Raspberry Pi and RTL-SDR to listen to ADS-B broadcasts from aircraft. These broadcasts contain the live current location and altitude of all aircraft in his area. When a landing aircraft is detected to be passing near his house, the Raspberry Pi sends a signal to another Raspberry Pi connected to a camera on his balcony, and that snaps a photo of the passing aircraft.

In terms of software, Arun uses dump1090 as the ADS-B decoder. For communications between the two Raspberry Pi's he uses Node-RED and Mosquitto in order to communicate with MQTT. On the second Raspberry Pi, gPhoto2 captures images from the camera, and then ImageMagick is used to write some text about the aircraft and photo on the image. Arun's post goes in further detail about the code and conditions he uses to determine when a photo should be snapped.

In the past we've posted about a similar project where an RTL-SDR and Raspberry Pi based ADS-B tracker was used with a servo mounted video camera to track and record video of passing aircraft.

Automatically Taking Photos of Passing Aircraft with a Raspberry Pi and RTL-SDR
Automatically Taking Photos of Passing Aircraft with a Raspberry Pi and RTL-SDR