Garmin GPS 500 Installation Manual

Also see for GNS 530: Pilot's manual Instructions Pilot's guide addendum Pilot's guide addendum Quick reference

Contents

Garmin GPS 500 Installation Manual Manual pdf 16 page image

Page 2-2 500 SERIES INSTALLATION MANUALRev Q 190-00181-022.2.6 ANTENNA LIMITATIONSGarmin’s GA 56 Antennas are recommended for installations where the airspeed of the aircraft is subsonic.In such installations, GA 56—Mod 1 or later—must be used. See the COM, VOR/LOC, and Glideslopeantenna specifications for their limitations.2.2.7 VHF COM INTERFERENCE OF GPSOn some installations VHF COM transceivers, Emergency Locator Transmitter (ELT) antennas, andDirection Finder (DF) receiver antennas can re-radiate through the GPS antenna. The 500 Series COMdoes not interfere with its own GPS section. However, placement of the GA 56 GPS antenna relative to aCOM transceiver and COM antenna (including the GNS 530 COM antenna), ELT antenna, and DFreceiver antenna is critical.Use the following guidelines, in addition to others in this document, when locating the 500 Series unit andits antennas.x GPS Antenna—Locate as far as possible from all COM antennas and all COM transceivers(including the 500 Series COM), ELT antennas, and DF receiver antennas. The GPS antenna isless susceptible to harmonic interference if a 1.57542 GHz notch filter is installed on the COMtransceiver antenna output.x Locate the 500 Series unit as far as possible from all COM antennas.Figure 2-1. GPS Antenna Installation ConsiderationsIf a COM antenna is found to be the problem, a 1.57542 GHz notch filter (Garmin P/N 330-00067-00) maybe installed in the VHF COM coax, as close to the COM as possible. This filter is not required for theGNS 530 transmitter.If a COM is found to be radiating, the following can be done:1. Replace or clean VHF COM rack connector to ensure good coax ground.2. Place a grounding brace between the 500 Series unit, VHF COM and ground.3. Shield the VHF COM wiring harness.2.2.8 COM, VOR/LOC, and Glideslope Antenna Installation InstructionsInstall the COM, VOR/LOC, and Glideslope antennas according to the manufacturer’s recommendations.Avoid running other wires and coaxial cables near the VOR/LOC antenna cable.