Guglielmo is a Linux, Windows (and in this recent update x86 MacOS) based RTL-SDR FM and DAB tuner software that supports SDRs including the RTL-SDR, Airspy, SDRplay, HackRF and LimeSDR. It is designed to be an easy to use program designed for media users, rather than hobbyist technical users.
Regarding the release of Version 0.5, Marco writes:
This release sports full mac (x86 only, sorry) and windows installers, DAB and FM scans and a preset editor.
PySDR is a free online textbook created by Dr. Marc Lichtman which explains many digital signal processing (DSP) and software defined radio (SDR) concepts in a clear, concise and easy to understand way. The guide includes multiple images and animations, as well as Python code examples.
Direction-of-Arrival (DOA) within DSP/SDR refers to the process of using an array of antennas to estimate the DOA of one or more signals received by that array. Once we know the direction a signal of interest is arriving from, we can isolate it from other signals/interference/jamming.
It is just like isolating a signal in the frequency domain by filtering it, except we are now working in the spatial domain (you can certainly combine both!).
We typically refer to the antennas that make up an array as elements, and sometimes the array is called a “sensor” instead. These array elements are most often omnidirectional antennas, equally spaced in either a line or across two dimensions.
DOA is a subset of beamforming techniques, where as the receiver, we are trying to steer a beam (our receiver’s antenna beam) towards the direction of an emitter. We may also steer a beam blindly across a wide range (e.g., 0 to 360 degrees) to figure out what signals are being received and from what direction.
A visual example of what happens to two signals when the interelement spacing of a direction finding antenna array is reduced below half a wavelength.
It was to be a US$149 FT8 receiver based on an open source RF chip design, capable of acquiring signals between 7 MHz and 70 MHz (technically 1 MHz to 100 MHz). Shipments were expected to begin in April 2023.
Unfortunately the Maverick team just released today that the project will be suspended indefinitely due to logistical issues. Backers of the project will receive a full refund.
The Maverick-603 project has been indefinitely suspended due to unforeseen logistical obstacles. No funds have yet been spent and all backers will receive full refunds. If you backed this project, your refund will be issued within the next week to the credit card you originally used. If your credit card is no longer valid, please contact Crowd Supply support before midnight UTC on Friday, April 28, 2023 to arrange your refund. If the Maverick-603 project is revived, we will post another update. Thank you for your support and patience.
During last years Radio Society of Great Britain (RSGB) 2022 convention, Brian Coleman (G4NNS) presented a talk about the UK Meteor Beacon Project. The idea behind the project is to use a transmit beacon and a network of user-run receivers to help detect and study meteors. The talk has recently been uploaded to YouTube.
Radio signals can reflect off the meteor and the ionized trail left behind when it enters the atmosphere. This trail is highly RF reflective, so it can allow distant radio stations to be briefly received.
In the talk Brian explains the meteor detection, and explains the project in more detail.
The UK meteor beacon project is a collaborative project between the amateur radio and radio astronomy communities to collect data on meteor events over the UK. Phase I has been to establish a transmit beacon and Phase II is to create a network of receivers to monitor the radio echoes from meteors and stream data over the internet to support the study of meteor events and their impact on the ionosphere. Another key objective is to make possible a range of accessible radio-related STEM projects building on the interest in space and astronomy.
RSGB 2022 Convention presentation - The UK Meteor Beacon Project
Recently we came across a new RTL-SDR app on the Google Play store called TXAdvance which appears to be designed for professional sound engineers working in TV/film/stage/music production industry. The app uses an RTL-SDR to display the RF spectrum, helping sound engineers manage the RF spectrum for all their wireless sound recording devices, ensuring there is no overlapping signals, interference or intermodulation from other transmitters that could corrupt audio.
Over on YouTube CiferTech has uploaded a video showing how to create a low cost 315 MHz jammer using an Arduino and a cheap 315 MHz transmitter circuit. The 315 MHz band is used in some countries by short range wireless devices such as garage door openers, tire pressure sensors, hone security systems and car keyfobs. Some wireless home security systems have been shown to be vulnerable to jamming, as jamming can stop an alarm activation signal being received by the base unit.
We want to note that building a jammer in most countries is completely illegal and the use of a jammer can result in severe penalties such as jail time.
On a related note, we also wanted to point out this recent tweet by Naomi Wu (@realsexycyborg), a popular Technology YouTuber who is based in China. Her tweet pointed out that some local market scammers in China use rigged weighing scales which can force the scale to display an artificially high value by using a wireless handheld remote. To combat this handheld jammers are sold so that shoppers can prevent the scammer's remote control from communicating with the scale. Although jamming is still most likely illegal in China, this could be considered an ethical use of a jammer.
.@c0un7z3r0 for it first- there are companies that rig popular brands of scales so they can be adjusted with a small remote control. The store sells jammers to use against the remote used by those rigged scales. pic.twitter.com/juHeLLobnD
Over on YouTube Robert from the Robert Research Radios channel has uplaoded a video showing how he has been using an RTL-SDR and rtl_433 to measure his Mazda CX5's wireless tire pressure sensors. The Mazda CX5 comes with TPMS tire pressure sensors in each tire, however when there is a low pressure warning, it does not actually tell you which tire in particular is low.
Robert used his RTL-SDR, rtl_433 and a custom script to read the wireless TPMS data coming from his tires and then matched the ID from each reading to the correct tire.
To go along with the video, Robert has uploaded a blog post explaining his setup and script.
OpenWebRX is an open source web based SDR receiver program that allows you or others (if you allow them to), to access your SDR over the internet. It is compatible with KiwiSDR, RTL-SDR, Airspy, SDRPlay and many other software defined radio hardware. It was originally developed by Andras Retzler, but since abandoned by him, with a semi-official fork being maintained at openwebrx.de. However, other forks like luarvique can exist that implement a new set of features.
The full set of additions and improvements reads as follows:
This is the package repository for the improved version of the OpenWebRX online SDR. The new and original features available in this version of OpenWebRX:
Built-in SSTV decoder with background decoding.
Built-in AIS decoder.
Built-in CW decoder.
Built-in RTTY decoder.
Built-in MP3 recorder for received audio.
Image browser for received SSTV images.
Adjustable noise filtering based on spectral subtraction.
Adjustable tuning step.
Improved touch screen operation, with panning and zooming.
Improved scroll wheel support, with tuning and zooming.
Improved tuning in CW mode.
Bandpass filter adjustable with scroll wheel.
More reliable SDRPlay devices operation.
Better map information, with distances.
Better APRS map information, with weather.
Configurable session timeout, with a policy page.
HTTPS protocol support (requires SSL certificate).
The code comes packaged for Ubuntu 22.04 (amd64, arm64) and Debian 11 (amd64 arm64, armhf). There is also a ready to use Pi 4 SD card image available, linked on the GitHub readme. The original forked code can be found at https://github.com/luarvique/openwebrx.
According to discussion over on the OpenWebRX groups.io, the fork also runs on a Pi 3. In the image Neil Howard from the groups.io forum demonstrates an SSTV image he received with an SDRplay clone using the luarvique fork of OpenWebRX.
SSTV Image received by the luarvique fork of OpenWebRX. Credit: Neil Howard
Stefan also notes:
The maker of OpenWebRX+ Marek and also the maker of the original version of OpenWebRX Jakob are reachable via a Telegram channel: https://t.me/openwebrx_chat
