TT26 ADS-B Transponder Installation Manual
24 January 2017
01633-00
Issue AC
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Trig Avionics Limited
5
2. Introduction
2.1 TT26 Description
The TT26 ADS-B transponder system is an ED-73E compliant Mode S level
2els datalink transponder, with support for ADS-B extended squitter,
elementary surveillance and SI codes, which also meets the relevant
environmental requirements of ED-14G. The TT26 has a nominal power
output of 250 watts, and meets the power output requirements for Class 1.
The TT26 has a built in WAAS GPS receiver which meets the requirements for
DO-229D class Beta1, and provides a position source for ADS-B transmissions
from the transponder. The ADS-B function meets DO-260B class B1S.
The built in pressure sensor provides altitude measurement up to 70,000 feet.
The TT26 is certified to ETSO C10b, ETSO C88b, ETSO C145c, ETSO
C112e and ETSO C166b A2.
The TT26 is controlled using a separate controller; the controller forms part of
the system and is required for full compliance with the altimetry TSO and
transponder TSO.
The TT26 runs from either 14 volt nominal or 28 volt nominal DC power
supply with no configuration changes required.
The TT26 responds to both legacy Mode A/C interrogations and to Mode S
interrogations from both ground radar and airborne collision avoidance
systems. In all cases, the interrogations are received by the TT26 on
1030MHz, and replies are transmitted on 1090MHz.
2.2 Interfaces
2.2.1
TT26 ADS-B Transponder Unit
The TT26 has a single TNC antenna connection to a transponder antenna, a
single SMA connector to an active GPS antenna, a single 25 way D-type
