ACR&Artex G406-4 ELT - Manual (Page 60)

ACR ELECTRONICS, INC / ARTEX PRODUCTS
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
G406-4 (453-5012)
25-62-21
Page 60 of 86
JUL 31/12
TASK 25-62-21-450-802
3. Antenna
SUBTASK 25-62-21-990-001
A. Selection
(1) Use only antennas approved for use with the G406-4 ELT. The ELT will not work properly
without being connected to an antenna for which it was designed.
(2) Verify the antenna selected matches the requirements of the specific installation.
Considerations include aircraft maximum rated speed, location restrictions, and any other
considerations specific to the installation.
NOTE: If the combination of a 121.5/243.0 MHz whip antenna and a 406 MHz whip antenna
is selected for installation, the requirements herein apply to both antennas.
SUBTASK 25-62-21-450-001
B. Location
(1) Select a suitable location for the antenna.
(a) Place the antenna in a location where the antenna can be installed within 15° of vertical
and with at least 30 inches (762 mm) of clearance from other antennas, particularly
VHF, in accordance with RTCA/DO-204, § 3.1.10.2.
NOTE: AC 43.13-2, Chapter 3 recommends a minimum distance of 36 inches (914
mm) clearance between antennas.
(b) Additional location guidance may be found in AC 43.13-2, Chapter 3, which deals
specifically with antenna installations.
SUBTASK 25-62-21-450-002
C. Installation
NOTE: Refer to the airframe manufacturer’s written instructions and AC 43.13-2, Chapter 3 for antenna
installation practices and requirements.
(1) Install a doubler plate if necessary to meet rigidity requirements. A 20 lb (9.1 kg) force applied
to the antenna in all directions should not cause an appreciable distortion in the aircraft skin.
(2) Install a ground plane if necessary. In certain applications, particularly those where antennas
are installed on composite, fabric, or wood airframes, a ground plane is required.
(3) Drill the antenna mounting holes and coax connector holes referring to the appropriate
antenna illustration for hole patterns and hole sizes.
(a) See "Figure 14. Whip Antennas 110-324 and 110-329 Outlines and Dimensions”, on
page 61 and "Figure 15. Rod Antenna 110-320 Outline and Dimensions”, on page 61.
(4) Mount the antenna referring to the appropriate antenna illustration for hardware
requirements, torque, and other applicable installation requirements.
(5) Two coax cables, 6 feet (1.8 m) long, are provided as part of the ELT kit. The 121.5/243.0
MHz cable has BNC connectors and the 406 MHz cable has TNC (antenna) and TPS (ELT)
connectors.