Garmin GDL 52 Installation Manual - Page 22

3.7 Antenna Installation 3.7.1 ADS-B Antenna Installation The GDL 52 unit includes an ADS-B antenna. An optional blade-type ADS-B antenna mounted on the bottom exterior of the aircraft can be connected to the GDL 52 via a cable connection to the unit's MCX connector. The GDL 52R requires an external ADS-B antenna for reception. The antenna should be mounted on the bottom of the aircraft and located at least 3.3 feet from high power transmitting antennas such as VHF Comm, HF transmitter, DME, Transponder, and Radar. The connection is made by attaching the cable from the external antenna to the BNC connector on the GDL 52R. The GDL 52/52R requires a UHF antenna that meets the following specifications: • Standard 50 Ω vertically polarized antenna with a VSWR < 1.7:1 at 978 MHz and < 1.5:1 at 1090 MHz. • TSO-C66, TSO-C74, or TSO-C112 antennas that also meet the VSWR specification. 3.7.2 GPS/SiriusXM Antenna Installation This section contains general information as well as installation information for GPS/SXM antennas. Garmin recommends the antennas shown in Table 3-6. However, any equivalent antenna that meets the specifications listed in Table 3-3 will work with the GDL 5X/5XR GPS external antenna input. Any equivalent antenna that meets the specifications listed in Table 3-4 will work with the GDL 5X/5XR external SiriusXM antenna input. The GDL 5X can receive GPS position information using the unit's internal antenna or by connecting an external antenna via the MCX connector. It is recommended to verify the ability of the GDL 5X to receive GPS information via the internal antenna as GPS reception quality is dependent upon the installation. The GDL 5X/5XR can receive GPS information with any connected aera or GDU 4XX display. A GPS antenna is not required to be connected to a GDL 5XR when the unit is connected to a Garmin Aera 660/795/796 or GDU 4XX display. For best performance, mount the GPS, SiriusXM antennas on top of the aircraft and at least 3.3 feet away from all high power transmitting antennas. Although no ground plane is required, the antenna typically performs better when a ground plane is used. The ground plane should be a conductive surface as large as practical, and is typically made of either aluminum sheet or wire mesh. Table 3-3 GPS Antenna Minimum Requirements Characteristics Frequency Range Gain Noise Figure Nominal Output Impedance Supply Voltage Supply Current Specifications 1565 to 1585 MHz 16 to 25 dB typical, 40 dB max Less than 4.00 dB 50 Ω 4.5 to 6.5 VDC up to 60 mA 190-02087-10 Rev. 1 GDL 51(R)/52(R) Installation Manual Page 3-3