SRA 1 Passive Unidirectional Antenna The antenna shall be a passive hypercardioid UHF receiving antenna with 6 dB on-axis gain, 13 dB or better rejection at 180°, and approx. 25 dB rejection at 135°. The antenna shall include an SA 61 stand adapter. The frequency range of the antenna shall be 658 MHz to 950 MHz, its diameter 152 mm, depth 65 mm, and weight 180 grams. The antenna shall be the SRA 1 from AKG.