For simple vertical antennas of equal height, maximum signalling distance varies as the square of antenna height.
Marconi's finding, and it is the reason early wireless stations built enormous masts. Frequently miscited as a claim about wavelength.
In practice
- Doubling a mast's height quadruples the distance it reaches, which is why early stations built towers rather than buying larger transmitters.
- A rural network gains more from one taller mast on a hill than from three more transmitters on the flat.