Garmin GDL 90 Installation Manual

Also see for GDL 90: Installation manual

General InformationGDL 90 Installation Manual 560-1049-00 Rev B 1-91.3.7.2 UAT AntennaThe GDL 90 requires a UHF antenna meeting the following specifications:• Standard 50Ω vertically polarized antenna with a VSWR < 1.7:1 at 978 Mhz• TSO-C66, C74, C112 or C154 antennas that also meet the VSWR specification.NOTECertain types of transponder antennas that utilize very thin radiator elements are onlyintended for use at 1030 and 1090 MHz. These types of antennas should be evaluated ona model-by-model basis to determine their suitability as UAT data link antennas.CAUTIONOperating the GDL 90 with no RF terminations on the Top or Bottom UAT Antennaports can result in equipment damage. Always operate the GDL 90 with the Top andBottom UAT Antenna ports terminated with a VSWR ratio of 3.0:1 or less.1.4 REGULATORY COMPLIANCE1.4.1 TSO AND ADVISORY CIRCULAR REFERENCES• TSO-C154 Universal Access Transceiver (UAT) Automatic Dependent Surveillance –Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz.• TSO-C145A Airborne Navigation Sensors using GPS Augmented by WAASNOTEUnauthorized changes or modifications to the GDL 90 may void the compliance torequired regulations and authorization for continued equipment usage.1.4.2 TSO AUTHORIZATIONTable 1-1. TSO AuthorizationFunction TSOMinimum PerformanceStandardSoftwareRTCA/DO-178BUATTransceiverTSO-C154, Class A1H, B1 RTCA/DO-282 Level B,CGPS/WAAS TSO-C145A, Class 1 RTCA/DO-229C, Class 1 Level B1.4.3 FCC GRANT OF EQUIPMENT AUTHORIZATION• FCC regulations for UAT are not yet finalized. The GDL 90 meets the proposed FCCregulations and international agency proposed regulations. Garmin AT has applied for a waiverfor UAT use in the United States during the interim until FCC regulations are adopted. Testingwas completed on the GDL 90 Universal Access Transceiver and documented in PD3621, GDL90 UAT FCC Certification Report. The data show compliance with FAA TSO-154 and FCCproposed rules to Parts 2 and 87 as commented in Docket No. 01-289. The data further