Sandia Aerospace STX 165 Installation Manual - Manual (Page 11)

Installation to be in accordance with FAA AC 43.13-1B
WARNING: The STX 165 and STX 165R must NEVER be turned on without the
antenna connected or a proper annunciator attached to the antenna output connector.
Failure to do so will result in the failure of the transmitter output device. This type
failure is not covered by the manufacturer’s warranty.
3.4 AIRCRAFT MOUNTING
3.4.1 STX 165
The STX 165 is rear mounted in the aircraft panel using four (4) 6-32 machine screws. To ensure
a secure attachment, the length of the mounting screw should be the thickness of the aircraft panel
plus 0.15 inches (extension into the STX 165 bezel). The STX 165 does not require any additional
mechanical support. The panel cut out is a standard 1/2 3ATI (Airline Transport Indicator). Allow
enough room behind the panel for the unit, connectors and harness.
A panel punch is available from the factory for a nominal charge. Contact the factory at
505.341.2930
Figure 3-1
Panel Cut Out Dimensions
3.3 Electrical
The STX 165 and STX 165R operate on 11-32Vdc. Power should be protected by a 1 amp fuse or
circuit breaker. J3, a 9 pin Sub-D connector, has system power, external Ident and RS 232 altitude
functions. J2 is a 15 pin Sub-D connector that has the Gilham Gray code and OAT functions. On
the STX 165 panel mount unit, the gray code connections are outputs on J2 and on the STX 165R
remote unit the gray code connections are inputs. Additionally Pin 8 of J2 is unswitched aircraft
power out that can be used to run other devices such as an encoder. Maximum current on Pin 8 of J2
is not to exceed 1 amp. When routing the antenna cable, sharp bends and routing near motors and
generators should be avoided. The antenna cable should be kept as short as possible (the antenna
sould be at least 3 feet away from the transponder itself). RG 400U or equivalent is the reommended
coax to use for the antenna cable.
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