Sec. 90.279  Power limitations applicable to the 421-430 MHz band.

    (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)................................................        250
Above 152-305 (above 500-1000)...............................        150
Above 305-457 (above 1000-1500)..............................         75
Above 457-610 (above 1500-2000)..............................         40
Above 610-762 (above 2000-2500)..............................         20
Above 762-914 (above 2500-3000)..............................         15
Above 914-1219 (above 3000-4000).............................         10
Above 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]