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How to Calculate Antenna Height & Distance

Knowing the height of an antenna allows you to calculate the distance that it could transmit a signal. Since antennae send and receive a radio signal, it can be obscured by the curvature of the Earth. The higher an antenna is positioned, the greater the distance the signal can be sent and received without being blocked by the Earth. Other considerations such as signal power and the directionality of the signal will also affect the ability to send and receive with the antenna.

Instructions

- 1
  Find the height of the antenna in feet. Multiply by two. So for a height of ten feet you would get the result of 20.
- 2
  Take the square root of the product of the height and two. In the current example, the square root of 20 would be 4.47. Which is the distance in miles for the line of sight connection between that antenna and another antenna on the ground.
- 3
  Multiply the square root result by 1.33 to get the radio horizon distance since radio waves follow the curvature of the earth slightly. So the distance of 4.47 miles, as a visual horizon, would be extended to 5.95 miles for a radio horizon.
- 4
  Perform the same calculations on the other antenna in the system and add the two results to get the total number of miles between the antennae.

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