Garmin GTX327 Installation Manual

Also see for GTX 327: Pilot's guide Pilot's guide Installation manual Pilot's guide Pilot's guide

GTX 327 Installation Manual Page 2-3190-00187-02 Revision KA. The antenna (Garmin P/N 010-10160-00) should be mounted away from major protrusions,such as engine(s), propeller(s), and antenna masts. It should also be as far as practical fromlanding gear doors, access doors, or other openings that could effect its radiation pattern.B. The main antenna should be mounted vertically on the bottom of the aircraft.C. Avoid mounting the antenna within three feet of the ADF sense antenna or any othercommunication antenna and six feet from the DME antenna.D. To prevent RF interference, the antenna must be physically mounted a minimum distance ofthree feet from the GTX 327.NOTEIf the antenna is being installed on a composite aircraft, sufficient ground planematerial must be added. Conductive wire mesh, radials, or thin aluminum sheetsembedded in the composite material provide the proper ground plane allowing theantenna pattern (gain) to be maximized for optimum transponder performance.2.4.2 Antenna InstallationInstall the antenna according to the antenna manufacturer’s instructions and FAA AC 43.13-1B andAC 43.13-2A.2.5 Cabling and WiringUse MIL-W-22759/16 or other approved wire, AWG #24 or larger wire for all interface connections. Thestandard pin contacts supplied in the connector kit are compatible with up to AWG #22 wire. In caseswhere some installations have more than one unit sharing a common circuit breaker, sizing and wiregauge is based on aircraft circuit breaker layout, length of wiring, current draw of units, and internal unitprotection characteristics. Do not attempt to combine more than one unit on the same circuit breakerunless it is specified on aircraft manufacturer approved drawings.In some cases, a larger gauge wire such as AWG #18 or #16 may be needed for power connections. Ifusing #16 or #18 barrel contacts, ensure that no two contacts are mounted directly adjacent to each other.This minimizes the risk of contacts touching and shorting to adjacent pins or to ground.Ensure that routing of the wiring does not come in contact with sources of heat, RF or EMI interference.Check that there is ample space for the cabling and mating connectors. Avoid sharp bends in cabling androuting near aircraft control cables.The following table lists examples of the recommended antenna cable vendors and the type of cable to beused for specific lengths of cable. Any cable meeting specifications is acceptable for the installation.The maximum coaxial cable attenuation at 1090 MHz must not exceed 1.5 dB, including connectors.The following table is for reference only, and lists some suitable cable types, along with the maximumlength based on an assumed loss figure of 0.2 dB per connector. Any 50 , double shielded coaxial cableassembly that meets airworthiness requirements and the 1.5 dB maximum loss figure (includingconnectors) may be used.