FM Reception

The shorter wavelengths of the higher frequency FM band:

• Reflect off obstacles
• Are absorbed by the ground
• Penetrate the ionosphere

Broadcasts in the FM band are limited to "line of sight" reception which is typically 40 km (25 mi). Even when out of a direct line of sight, the signal may be reflected into areas that would be in a "shadow" otherwise. Factors which affect the line of sight include:

• Height of the broadcast antenna
• Height of the receiving antenna
• Terrain and buildings in the broadcast path