Sirio Antenna GPA4070 40-70 MHz Ground Plane Base Antenna Base station antenna, mono-band omnidirectional, unity gain made of aluminum alloy 6063 T-832 perfect protection against the worst weather conditions Type: 1/4 ground plane large band frequency range: 135 - 175MHz impedance: 50 radiation (H-plane): 360 omnidirectional radiation (E-plane) Type: 1/4 ground plane large band frequency range: GPA 40-70: Tunable 40 70 MHz, Impedance: 50, radiation (H-plane): 360 omnidirectional Bandwidth @ SWR 2: 3.7 MHz @ 40 MHz, SWR @ res. freq.:  1.2 @ start freq., max. power (CW) @ 30c: GPA 40-70: 1000 watts, connector: UHF-female Materials: Aluminum, chromed brass, nylon, wind load