Uat Antenna Requirements; Gps Antenna Requirements - FreeFlight ADS-B FDL-978 Series Installation Manual

ADS-B FDL-978 Series and
Lite Series Installation Manual
Document No. 87343 Rev F
The TC978 is not required if the FDL-978-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
•
If connected, the TC978 will not accept control inputs and will mirror the transponder or
primary controller. If communication with the primary controller is lost for 60 seconds,
then the TC978 will assume the role of the controller and allow control inputs (squawk,
IDENT). If the TC978 is used in this manner, it is strongly recommended to set the
squawk code first on the transponder.

1.4.2 UAT Antenna Requirements

The FDL-978 Series and FDL-978 Lite Series require a TSO-C66, C74, C112, or C154 Ultra
High Frequency (UHF) antenna(s). 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 20-165A) single bottom mounted
antenna (TSO-C154c Class A1S) installations are allowed.

1.4.3 GPS Antenna Requirements

The FDL-978 Series (with internal GPS) and FDL-978 Lite Series require a TSO-C144 (DO-228)
antenna. A TSO-C190 (DO-301) compliant GPS antenna may be used for the FDL-978 or FDL-
978 Lite 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 1.7.1). Use of other antennas or cables may not
meet all the performance characteristics required by TSO-C145c.
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