General Information; Introduction; Equipment Description; General Description - Honeywell BENDIX KING KT 73 Installation Manual

Preliminary - Subject To Change Without Notice
BENDIX/KING
1.1

INTRODUCTION

This manual contains information relative to the physical, mechanical, and electrical characteris-
tics of the Honeywell KT 73 Mode S Transponder. Installation and operating procedures are also
included. Information relative to the maintenance, alignment, and procurement of the replacement
parts may be found in the KT 73 Maintenance/Overhaul Manual, P/N 006-15563-0000.
1.2

EQUIPMENT DESCRIPTION

1.2.1

General Description

The KT 73 General Aviation Mode S Transponder is designed to meet TSO-C112 for a Class 2A
ATCRBS/Mode Select Airborne Transponder System. It is a panel mounted transponder that ful-
fills the role of the airborne beacon equipment according to the requirements of the Air Traffic Ra-
dar Beacon System (ATCRBS). Its functionality includes replying to ATCRBS Mode A and C, In-
termode and Mode S interrogations as well as handling Comm A and B Mode S Data Link proto-
cols. The basic surveillance capability of the KT 73 satisfies the European Mode S mandate.
The KT 73 will pass Surveillance (UF 4 and 5) and Comm-A (UF 20 and 21) interrogations (minus
the 24 bit Aircraft Address) to the ADLP (Airborne Data Link Processor). It will also be capable of
receiving messages from the ADLP. It will also be capable of receiving messages from the ADLP
and sending the messages to the ground in Comm-B (DF 20 and 21) replies. The transponder/
ADLP will communicate using a RS-232 hardware interface and the RS-232 protocol developed
by Lincoln Labs. Other Mode S formats that the KT 73 can handle include Uplink Formats 0 and
11 and Downlink Formats 0, 4, 5, 11, 16, 17, and 18.
The KT 73 also provides Mode "C" or altitude reporting information. When the KT 73 is operated
in the "ALT" Mode and used in conjunction with an encoding altimeter, the flight level altitude is
displayed in addition to the 4096 code, and the altitude information is transmitted to the ground in
response to Mode "C" interrogations.
The Mode S function of the KT 73 will allow the ground station to individually select the aircraft by
its Aircraft Address assigned to the aircraft by the FAA.
When the "IDT" button is pressed, the current 4096 code and an additional special ident pulse are
transmitted by the KT 73 in response to a Mode A interrogation, to insure positive identification.
A test mode is also included in the KT 73 to confirm that the unit is operational.
The KT 73 implements the following DO-181C functions: Basic Transponder, Minimum Data Link
Transponder, and Extended Squitter Capability. The KT 73 implements its data link via an RS-
232 bus. The KT 73 does not support enhanced data link.
The KT 73 does not have full ELM capability and does not support Comm-D ELM protocol. The
KT 73 is not a TCAS-compatible transponder.
1.2.2

Hardware

The KT 73 features an all solid state transmitter with microprocessor control. Mode and Code se-
lection are performed by the rotary knobs, and all functions including flight level altitude, 4096
code, and aircraft address are presented on the gas discharge display. The KT 73 is derived from
the KT 70 Mode S transponder and will retrofit into KT 70, KT 71, and KT 76C installations.
The KT 73 has a Gas Discharge Display, Mode Select Knob, VFR pushbutton, Ident pushbutton,
and four ident code selector knobs.
Rev 0, October/2002
SECTION I

GENERAL INFORMATION

10563I00.JA
KT 73
Page 1-1