(a) Base station authorizations in the 421-430 MHz band will be subject to Effective Radiated Power (ERP) and Effective Antenna Height (EAH) limitations as shown in the table below. ERP is defined as the product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. EAH is calculated by subtracting the Assumed Average Terrain Elevation (AATE) as listed in table 7 of Sec. 90.619 from the antenna height above mean sea level.
Limits of Effective Radiated Power (ERP) Corresponding to Effective
Antenna Heights (EAH) of Base Stations in the 421-430 MHz Band------------------------------------------------------------------------
Maximum
effective
radiated
Effective antenna height (EAH) in meters (feet) power
(ERP)
(watts)------------------------------------------------------------------------0-152 (0-500)................................................ 250Above 152-305 (above 500-1000)............................... 150Above 305-457 (above 1000-1500).............................. 75Above 457-610 (above 1500-2000).............................. 40Above 610-762 (above 2000-2500).............................. 20Above 762-914 (above 2500-3000).............................. 15Above 914-1219 (above 3000-4000)............................. 10Above 1219 (above 4000)...................................... 5------------------------------------------------------------------------
(b) The maximum transmitter power output that will be authorized for control stations is 20 watts. [52 FR 6157, Mar. 2, 1987, as amended at 58 FR 44957, Aug. 25, 1993]