ACK Whip Antenna for E–04 In order to meet the requirements of COSPAS/SARSAT TSO C–126b,TSO C-91a, and FAR 91.207 an approved antenna must be used. The antenna supplied with the ELT P/N E–04.8 is a monopole, dual frequency antenna design. It has a recommended operating speed of up to 260 knots. The coaxial cable supplied is RG–58, and is 5 feet long. A longer or shorter cable may be fabricated using RG–58 or equivalent cable, and Amp 227079–5 connectors. The insertion loss of the cable assembly at 406 MHz should not exceed 2 dB. At 121.5 MHz the insertion loss should not exceed 3 dB. The cable should be a minimum of 2 feet in length.
The antenna may be mounted internally in composite construction, and tubular fabric covered aircraft, as long as the fabric or composite material is of a non conductive nature. The antenna must be mounted externally, on airframes of metallic construction. The antenna should be mounted as close to the ELT transmitter as practical. The coaxial cable connecting the antenna to the ELT transmitter, should not run in close proximity to comm radio coaxial cables, and should avoid crossing aircraft production breaks. (i.e. Riveted fuselage sections) The antenna must be mounted within 30 degrees of vertical, when the aircraft is in normal flight attitude. The installed antenna must be able to withstand a static load of 100 (one hundred) times it’s weight (13 lbs.) applied to the base of the antenna, along the longitudinal axis of the aircraft. The antenna should be mounted a minimum dis-tance of three feet (1 meter) from any vertically polarized communication antennas. (i.e. Antennas radiating in the 118–137 MHz band.)
