https://www.ibpt.be/consommateurs/publication/decision-du-29-aout-2023-concernant-l-attribution-du-spectre-40.660-mhz---40.690-mhz-a-des-stations-de-radiocommunications-privees-dinstruction-individuelle-dintercommunication-technique-et-detudes-utilisees-par-des-radioamateurs