. Artex whip antenna, P/N 110-773
The antenna requires a ground plane. On aircraft constructed with non-conductive materials, such as composite materials or fiberglass, a ground plane must be added. Ideally, the ground plane should extend out from the antenna mounting point at least 24 inches (60cm) in every direction. Many times this is not possible, but an effective plane can be constructed as follows:
A ‘doubler’ layer of sheet metal, such as aluminum, can be mounted under the aircraft skin. Alternatively, four or more ‘radials’ fastened to the underside of the fuselage skin can be used to fashion a ground plane. Each radial can be metallic tape, 22 AWG wire, etc. Tape should be at least 1 inch (25.4 mm) wide and each radial 24 inches (60 cm), minimum. The ground plane connects to the shield of the RF antenna connector. Resistance between the ground plane and shield connection should be maintained at 0.003. maximum. A star washer should be used between the antenna connector housing and ground plane. Take precautions to guard against corrosion, loosening, etc. See diagram below:
An effective, light-weight, ground plane can be formed from radial strips of copper foil. A doubler may be required to strengthen resistance to impact, vibration, ice, etc. and can serve as connection points for the radials.
Figure 7 - Antenna Ground Plane
Specific antenna installation instructions follow. Also, AC 43.13 provides additional guidance for antenna installations.
2.4.1 Whip Antenna – Artex P/N 110-773
See Figure 24. Refer to AC 43.13 for guidance. It is the responsibility of the installer to determine the appropriate and adequate antenna installation.
To ensure adequate support for associated air loading during flight, use of a backing plate or doubler (not supplied) may be required.
2.4.1.1 Type of Aircraft
The Whip Antenna (P/N 110-773) is designed for installation on fixed wing subsonic aircraft and is rated for a maximum airspeed of 200 KIAS (Knots Indicated Airspeed at Sea Level).
NOTE: Artex does not recommend the use of the Whip Antenna for helicopter installations.
2.4.1.2 Location
The antenna must be mounted on the top of the aircraft to assure maximum ‘visibility’ of satellites (406 MHz). The best location is the upper aft portion of the fuselage. It should be mounted vertically and away from projections such as a propeller, tail surfaces, or the shadow of larger antennas.
2.4.1.3 Preparation
1. Prepare the surface for antenna installations in such a manner to ensure a ground contact of less than 0.003.. If bare metal surfaces are needed for surface preparation they should be treated with Alodine.1200 (or similar compound) to eliminate aluminum oxidation. 中國航空網 m.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL ME406P ELT(14)
