The Chiron 3 rocket has two emergency beacons that operate for several days. One in the nose cone and one in a 3d printed shroud on the outside of the coupler section.
An Atmel 328p microprocessor awakes from hibernation every few seconds and generates a tone for 100ms . This low duty-cycle allowes for the extended duration.
STX882 and 328p glued together.
Transmitter module, lipo battery and external connectors in a 3d printed ABS shroud.
3d printer shroud on the outside of the coupler section.