Advertisers Index AIE Inc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Appareo . . . . . . . . . . . . . . . . . . . . . . 13 & 47 Applied Avionics Inc. . . . . . . . . . . . . . . . . . 11 Aspen Avionics. . . . . . . . . . . . . . . . . . . . . . 17 Astronics. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Avidyne. . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 GPS antennas are mounted on top, and separation from other antennas is critical to proper operation. Avionics News . . . . . . . . . . . . . . . . . . . . . . 72 Avionics Shop . . . . . . . . . . . . . . . . . . . . . . 59 BendixKing . . . . . . . . . . . . . . . . . . . . . . . . . 71 Bose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Cincinnati Avionics . . . . . . . . . . . . . . . . . . . 59 Cobham Aerospace Communications. . . . 15 Cobra Systems . . . . . . . . . . . . . . . . . . . . . 58 Corvallis Aero Service . . . . . . . . . . . . . . . . 58 DAC International. . . . . . . . . . . . . . . . . . . . . 7 Duncan Aviation . . . . . . . . . . . . . Back Cover FDS Avionics Corp. . . . . . . . . . . . . . . . . . . 19 FLYING Magazine. . . . . . . . . . . . . . . . . . . 37 Garmin . . . . . . . . . . . . . . . Inside Front Cover Georgia Avionics . . . . . . . . . . . . . . . . . . . . 64 GlobalParts.aero . . . . . . . Inside Back Cover ANTENNAS & ADS-B Continued from page 49 Gogo Business Aviation. . . . . . . . . . . . . . . 70 Mid-Continent Instruments and Avionics. . 23 Pacific Southwest Instruments . . . . . . . . . . 1 PS Engineering . . . . . . . . . . . . . . . . . . . . . 41 Rotorcraft Support Inc.. . . . . . . . . . . . . . . . 51 SkyWorld Avionics . . . . . . . . . . . . . . . . . . . 31 Trig Avionics . . . . . . . . . . . . . . . . . . . . . . . . 36 Tri-Star Technologies . . . . . . . . . . . . . . . . . 25 True Blue Power . . . . . . . . . . . . . . . . . . . . . 3 Check to see if the antenna meets the required spec - and also remember to check and see if using a splitter is allowed under the STC for whatever equipment it's connected to. Note that performance of all equipment connected to an antenna can be affected by impedance, gain, etc. Cabling is also an issue. A little corrosion between the antenna and aircraft skin can change the impedance and affect performance." Composite airplanes can present special issues when installing antennas, according to Brand. "For installations on Cirrus, Columbia and the like, try to use the existing antennas whenever possible - failing that, check service bulletins or contact the manufacturer for guidance," he said. Composite airplanes typically have either foil or an embedded wire grid to provide a Faraday cage, which can be used as a ground plane for antennas. "For L-Band ADS-B and transponder - 50 -