Installation Instructions

ADS-B FDL-DB Dual Band Series

Installation Manual

Document No. 88552 Rev A

1-8

Altitude Output

Pressure altitude data is output on an RS-232 serial port.

The TC978 is not required if the FDL-DB-XVR is connected to a transmit controller

(transponder) and/or display that can provide, as a minimum:

• Mode A code entry and display

• IDENT control and display

• ADS-B transmit and ADS-B position failure status annunciations

1.4.2 UAT Antenna Requirements

The FDL-DB Series requires an Ultra High Frequency (UHF) antenna(s) with at least one of the

following: TSO-C66, C74, C112, or C154. Ensure that the antenna has 50Ω impedance with a

Voltage Standing Wave Ratio (VSWR) < 1.7:1 at 978 MHz. The Comant CI-101 and RA Miller

AV-22 ball antennas and the Comant CI-105 blade antenna meet these requirements.

In Class A1H ADS-B equipment (TSO-C154c) installations, antenna diversity (meaning a top

and bottom antenna) is required. In Class A1S (single antenna) installations only one antenna

(bottom) is used. For airworthiness approval of ADS-B out systems (AC 20-165B) single bottom

mounted antenna (TSO-C154c Class A1S) installations are allowed.

1.4.3 GPS Antenna Requirements

The FDL-DB Series (with internal GPS) require a TSO-C144 (DO-228) antenna. A TSO-C190

(DO-301) compliant GPS antenna may be used for the FDL-DB Series. Installation of a TSO-

C190 antenna is only recommended for anticipated future upgrades to TSO-C145c Class Beta

2, 3, or 4 navigation sensors and avoids the need for a GPS antenna change at that time.

The performance of the internal GPS is affected by the gain, noise figure, impedance, and

frequency selectivity characteristics of the antenna. They should be used only with the

recommended antenna and cable (See Section 2.11.2). Use of other antennas or cables may

not meet all the performance characteristics required by TSO-C145d & TSO-166b.