Garmin GPS 155XL Installation Manual

Also see for GNC 300XL: Pilot's guide and reference Installation manual

Garmin GPS 155XL Installation Manual Manual pdf 19 page image

GPS 155XL/GNC 300XL Installation Manual Page 3-3190-00067-22 Revision F3.5 REQUIRED INSTALLATION ACCESSORIES NOT SUPPLIEDThe following installation accessories are required but not provided (GNC 300XL only).• Comm Antenna—Broad Band 50 Ohm Vertically Polarized with Coaxial Cable• Headphones—500 Ohm Nominal Impedance• Microphone—Low Impedance Carbon or Dynamic with Transistorized Preamp3.6 ANTENNA INSTALLATIONFor the COMM antenna, follow the manufacturer's instructions (GNC 300XL). The remainder of thissection applies to the GPS antenna. The GA 56 Antenna outline and footprint dimensions are shown inFigure D-1.1. Using the backing plate as a template, mark the location of the mounting holes and the throughhole for the coaxial cable. Drill or punch the holes.2. The antenna installation must provide adequate support for the antenna considering amaximum drag load of 5 lbs. for the GA 56 antennas (at subsonic speed). Install a doublerplate to reinforce thin skinned aircraft. Observe guidelines for acceptable installation practicesas outlined in AC 43.13-2A.3. Seal the antenna and gasket to the fuselage using a good quality electrical grade sealant. Usecaution to ensure that the antenna connector is not contaminated with sealant. Ensure that themounting screws are fully tightened and that the antenna base is well seated against the gasket.CAUTIONDo not use construction grade RTV sealant or sealants containing acetic acid. Thesesealants may damage the electrical connections to the antenna. Use of these typessealants may void the antenna warranty.