Narco Avionics AT165 TSO Operation Manual - page 3
PRODUCT DESCRIPTION
The AT165 TSO is a panel-mounted transponder with additional altitude and timing functions. The AT165
consists of a receiver tuned to the frequency of a ground interrogation station (1030 MHz), logic circuitry to
check the validity of the received interrogation and encode a reply containing pertinent identification
information, and a transmitter, which sends the coded reply to the ground station. When connected to an
optional Altitude Digitizer (AR850) coded altitude information will be transmitted to the ground station.
The AT165 utilizes a single knob for error free code entry even in turbulence. Push button controls are used to
access and manipulate the added features. The front panel display has two distinct areas, one for the primary
transponder functions and the second for the altitude and timing functions.
The AT165 has been designed for 14V or 28V operation. If the AT165 is replacing an existing AT50TSO,
AT50A, AT150, or AT155 that uses an MP10 or a passive voltage converter, these do not need to be removed.
OPERATION
Function Selector
Switch
Code Selector / Data
Entry
Switch
FIGURE 1-1 AT 165 FRONT PANEL
Function Selector Switch
The function selector is a four position rotary switch. The four positions are:
OFF
- Turns off all power to the transponder.
SBY
- Turns the transponder power supply on. When in
SBY
, the transponder will not reply to any
interrogation.
SBY
is used at the request of the air traffic controller to selectivity clear his scope of
traffic. When in this mode SBY will be shown on the Code display window.
ON
- Places the transponder in Mode A, the aircraft identification mode. In addition to the aircraft's
identification code, the transponder will also reply to altitude interrogations (Mode C) with discrete
signals that do not contain altitude information. When in this mode ON will be shown on the Code
display window.
ALT
- The
ALT
position activates all the necessary circuitry (transponder to optional altitude digitizer and
return) to respond to ATC (Air Traffic Control) altitude interrogations and aircraft identification
interrogations with standard pressure altitude (29.92 inches Hg). The
ALT
position may be used in
aircraft that are not equipped with the optional altitude digitizer, however, the only response will be
discrete signals that do not contain altitude information. When in this mode ALT will be shown on the
Code display window.
NOTE:
The
Audio Alert
functions are NOT available on the KT76/KT78 replacement.
PRINTED IN U.S.A. REV C JANUARY 2005