What kind of separation is required between radio towers?
If you build or modify a tower within 3.2 km of a Directional AM station or within 1 km of a Non-Directional AM station, you are required by the FCC to do a partial “proof of performance” before and after a construction or modification of the tower. A partial proof requires measurement of 8 points on every radial that appeared on the original proof when the station first went on the air. If a station has 10 radials, 80 points or street intersections must be measured before and after construction, to meet the regulation. The two sets of measurements are compared to determine if any re-radiation has taken place. If the AM station has 10 ‘day’ radials and 10 ‘night’ radials, 160 points must be measured to compare to the pre-construciton measurements. Each AM station is different. Some have 2 patterns that need to be measured, some have one. Some stations have eight radials (minimum), some have 18…. It depends on how many towers are used to broadcast the signal.
