47 CFR § 80.771 - Method of computing coverage.

Compute the + 17 dBu contour as follows:

(a) Determine the effective antenna height above mean sea level according to the procedures in §§ 80.757–80.761.

(b) Determine the effective radiated power according to § 80,765. Determine for each radial the distance from the antenna site to the + 17 dBu point of field strength using procedures of §§ 80.765 and 80.767.

(c) Plot on a suitable map each point of + 17 dBu field strength for all radials and draw the contour by connecting the adjacent points by a smooth curve.