Increasing antenna height primarily improves which aspect of coverage?

• A. Line-of-sight distance
• B. Transmitter power efficiency
• C. Receiver dynamic range
• D. Antenna bandwidth

Answer: (A)

Raising antenna height increases line-of-sight range. Radio waves travel in straight lines, so the higher the antennas, the farther the horizon extends over the Earth's curvature. The approximate horizon distance grows with the square root of the antenna height, so taller antennas expand the coverage area by improving the unobstructed path between transmitter and receiver. This effect is especially important in VHF/UHF, where signals tend to be primarily line-of-sight. Height does not directly change transmitter power efficiency, receiver dynamic range, or the antenna’s bandwidth, which depend on different aspects of the system.