The AT-70 provides a significant gain over the 1/4-wave monopole. The best impedance match is provided when the radials are angled downward from the vertical at a 45-degree angle, causing a 1/2-wave dipole antenna effect. A ground plane antenna exhibits a circular coverage pattern, perpendicular to the vertical element. The antenna should be positioned so that the radials are closest to the nearest boundary such as a central location on the floor, wall or ceiling and functions best when inverted. The AT-70B UHF antenna signal booster works between 620~960MHz and offers 13 dB of gain to compensate for the antenna cable loss and allow better S/N ration on receiving signals to increase operating range and signal stability. FEATURES:AT-70[ Frequency Range: UHF 620~960MHz[ Impendence: 50 Ohm[ Connector: TNC male [ Dimensions: 165(H)x150(£X)mm / 6.5(H)x5.9(£X)""[ Weight: 142g / 5.0ozAT-70B[ Frequency Range: UHF 620~960MHz[ Max. Input Level: <+20dBm[ Noise Figure: <2.5dB (Center Band)[ Gain: +13dB (Center Band)[ Input SWVR: Ø2.5[ Impedance: 50Ohm[ Power Supply: 8V DC, regulated[ Current Drain: @80mA[ Dimensions: 100(L)x28(£X)mm / 3.9(H)x1.1(£X)""[ Weight: 102g / 3.6oz ";