It would be a fun hackathon project to build such a thing out of the components you could find in typical office equipment, and I wouldn't expect it to take a competent EE more than a few hours (if you'll allow continuous wave Morse code as a transport layer).

But based on where the embassy is, it's probably easier to stand near a window and get on the WiFi from Pret a Manger next door.

AX.25