Based on the SI5351 clock generator, this is a simple VHF beacon with the target to be used for "Fox hunt". It explains its name : foxy.
To know more about the projet : the article in french
The harware is based on an Arduino Nano, a SI5351 and a filter based on LC components. The Kicad project (schema and PCB) are available in the electronics folder. Fabrication files are available in the electronics/foxy/Gerber folder.
Very simple software here which relying on the SI5351 library from https://github.com/etherkit/Si5351Arduino The code can be built and deployed with platform.io