Over on the YouTube channel "SecPGH" a talk by Grey Fox titled "Introduction to Software Defined Radio For Offensive and Defensive Operations" has been uploaded from the BSidesPGH 2024 conference. BSidesPGH 2024 was a security conference held in Pittsburgh, PA, USA on July 25.

The talks are generally about network security, however, Fox's talk is all about RF security topics and software defined radio. In the talk, he introduces SDR, and devices like the Flipper Zero and demonstrates various basic examples such as receiving FM from a handheld radio and ADS-B.

Next, he goes on to demonstrate security topics such as showing how to capture and analyze signals from a 433 MHz security alarm using an RTL-SDR and Flipper Zero, and how to jam frequencies and replay captured signals. Finally, he demonstrates WiFi cracking with the help of Kali Linux and Flipper Zero with WiFi dev board attached.

Over on hackster.io we've seen a story about how maker Jon Dawson designed a self-contained software-defined radio based on the Raspberry Pi Pico that can receive 0 - 30 MHz, with up to 250 kHz of bandwidth. The Raspberry Pi Pico is a microcontroller board based on the Raspberry Pi Foundation's own RP2040 chip.

The Pi Pico Rx's front end consists of a Tayloe Quadrature Sampling Detector (QSD) mixer which makes use of the PIO (Programmable Input/Output) feature on the RP2040. The circuit also has an encoder knob for tuning and a small OLED screen.

Jon had originally created the Pi Pico Rx on a custom PCB, however, his latest work brings the cost down by showing that it can just as easily be implemented on a breadboard with through-hole components.

The full writeup can be found on Jon's blog "101 Things", as can the open source firmware. He has also uploaded a YouTube video explaining and demonstrating the project which we've embedded below.

Over on his YouTube channel, Simon has uploaded a video showing how while on holiday he was able to explore the various HD Radio stations available around the USA. 

If you are in the USA, you might recognize HD Radio (aka NRSC-5) signals as the rectangular looking bars on the frequency spectrum that surround common broadcast FM radio signals. These signals only exist in the USA and they carry digital audio data which can be received by special HD Radio receivers. Earlier in 2017 a breakthrough in HD Radio decoding for SDRs like the RTL-SDR was achieved by Theori when he was able to piece together a full HD Radio software audio decoder that works in real-time. Nowadays you can use software like HDFM - HD Radio GUI to easily receive HD Radio with an RTL-SDR.

In his video Simon shows the various HD Radio signals he found while on holiday, and also shows some of their secondary features, including traffic data, and weather radar maps. Interestingly he also spots HD Radio in the AM bands, but finds his signal is not strong enough to decode.

The rest of the video explores other signals he finds such as a studio link, and TV audio signals.

Over on Hackaday we've seen a post about Dan's (KB6NU) talk at the HOPE (Hackers of Planet Earth) conference about how Ham radio can be for hackers, and how hackers are the future of ham radio. Hackers in this context mean people who enjoy experimenting with electronics, building stuff, and understanding how things work.

Dan's slides have been uploaded on his blog. The slides emphasize how ham radio is not only about the traditional thought of making contacts which is probably in most people's heads, but also about hacking radios, antennas, microcontrollers, satellites, pico balloons, digital communications, GNU Radio and more. Dan mentions his goal is to promote ham radio to the much younger hacker crowd, where he believes it is underrepresented.

In one of her latest videos on YouTube, Sarah from the SignalsEverywhere channel shows how we can use a program called "IZ8BLY Phase 3D (AO-4) Satellite Decoder" to decode the 'Mid-Beacon' on the QO-100 satellite. QO-100 is a commercial geostationary communications satellite that also contains a popular transponder for amateur radio.

However, there is also an interesting beacon called the mid-beacon that can be decoded, which provides some information about the satellite. In the video, Sarah shows how this beacon can be decoded with the software from IZ8BLY. As QO-100 is only visible from Europe, the Middle East and Africa, Sarah uses a WebSDR to receive the signal from the USA, then pipes the audio into the IZ8BLY decoder via Virtual Audio Cable.

Thank you to Ihar Yatsevich for writing in and sharing with us his open-source WSPR beacon project. The WSPR beacon consists of a custom PCB with ATMega328 microcontroller, GPS module, single transistor amplifier, and Si5351 with TCXO.

The result is a very simple, portable WSPR beacon that can be heard all over the world. However, it appears that no band filters are built into this, so you will need to add a bandpass filter for the WSPR band that you are using.

WSPR (Weak Signal Propagation Reporter) (pronounced "whisper") is an amateur radio digital HF mode designed to be decodable even if the signal is received with very low power. Because of this design, even low-power transmitters can be received from all over the world. It can also be used to help determine HF radio propagation conditions as WSPR reception reports are typically automatically uploaded to wsprnet.

If you are interested, Ihar has written about his project in more detail over on Reddit. 

Welcome back to Sarah from the SignalsEverywhere YouTube channel who has recently returned to producing videos from a hiatus. In her latest video, Sarah shows off her new OP25 Mobile Control Head Android App which allows you to implement a full P25 digital radio scanner at a fraction of the cost of a commercial digital scanner. In the past, Sarah had released a similar application written for the Raspberry Pi but has decided to shift her focus to writing an equivalent Android app that is less clunky and can be deployed for a lower cost. 

The app controls and displays information from the OP25 software that runs on a Raspberry Pi with RTL-SDR connected. It works by using a server application on the Raspberry Pi that manipulates the OP25 instance and its configuration files.

Sarah writes:

The application is a wrapper for OP25 that uses a raspberry pi and an android device to provide users with a mobile control head for their OP25 P25 scanner setup. Currently it's just a basic application but I'll be adding features like automatic site switching, etc.

OP25MCH: https://github.com/SarahRoseLives/OP25MCH

There is also a separate application I call the OP25Display which is just a display for a users existing OP25 instance.

OP25Display: https://github.com/SarahRoseLives/op25display