Norwegian hill signals

From the 8th to the 11th century, Vikings used hilltop bonfires to signal raids or gather troops. This system relied on visual signals visible over great distances, similar to early signal flags and light codes in amateur radio. Hill signals underscore the importance of line-of-sight communication, a concept vital in radio wave propagation and antenna placement. The Vikings’ use of strategically placed signals for efficient communication parallels amateur radio operators’ use of high ground and clear sightlines to optimize signal strength and coverage, ensuring effective long-distance communication.