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
   Effective antenna height (EAH) in meters (feet) Maximum effective radiated
   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]