Sandia Aerospace STX 165 Installation Manual - Manual (Page 9)

Section 2 Installation Considerations
2.1 GENERAL
The STX 165 is self contained panel mounted Mode C transponder with a built-in encoder. In
addition to providing Mode C altitude for it’s internal use, the STX 165 outputs the encoders pres-
sure altitude in an RS 232 format for use with other on board systems that require pressure altitude
information. The baud rate for the RS 232 output is selected (9600 or 1200 baud) in the installer
setup mode during installation. A Sandia STP 78 OAT probe (Part Number 305561-91) can also be
installed as an option with the STX 165. When the STP 78 is installed the STX 165 will display
Outside Air Temperature, Density Altitude, and an Icing Alert. The icing Alert will come on at a
preset temperature that is selected by the user in the user set up mode.
The STX 165R is a remote Mode C transponder designed to be used with other navigation systems.
SANDIA
provides a Interface Control Document to those that wish to interface with the STX 165R.
The ICD can be obtained from SANDIA Aerospace by contacting the factory at 505.341.2930. The
STX 165R can be hard mounted in the aircraft or mounted with the use of a mounting tray. The
STX 165R requires altitude input from an encoder, such as the Sandia SAE 5-35, in either RS 232 or
Gilham Gray code format.
2.2 MOUNTING CONSIDERATIONS
2.2.1 STX 165 Panel Mount
The STX 165 is designed to be rear mounted in a 1/2 3ATI cutout. The ATI (Airline Transport Indi-
cator) form factor is used in most corporate and commercial aircraft. It provides a professional look
while keeping space requirements to a minimum. The STX 165 is attached to the aircraft panel with
four user supplied 6-32 machine screws. The length of the mounting screw should be the thickness
of the aircraft panel plus 0.15 inches (extension into the STX 165 bezel). A template is provided
with the STX 165 to aid in panel cutout. SANDIA aerospace also has a panel punch avialable for
use in installing the STX 165. Contact the factory at 505.341.2930 regarding use of the panel punch.
2.2.1.1 Optional 3” Adapter Plate
An adapter plate is available to allow the STX 165 to mount in a standard 3” instrument hole. The
2.2.2 STX 165R Remote Mount
The STX 165R can be remote mounted in the avionics bay or other location in or outside a pressure
vessel. The STX 165R can be mounted in any orientation by attaching the unit to a structure using
the slots on the mounting tabs. The mounting tabs allow for four point to secure the STX 165R, but
only three are required. The STX 165R can also be mounted using the optional mounting tray. The
tray should be secured with the use of three (3) number 6-32 or 8-32 pan head machine screws.
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