Connector Pinout Information
190-01499-02
GTX 3X5 Transponder TSO Installation Manual
Rev. 9
Page 5-11
5.8
Suppression Bus
The EXTERNAL SUPPRESSION is intended for connection to other L-band equipment, such as a DME or UAT. The
output is active whenever the GTX 3X5 transmits. When driven by another source, the GTX 3X5 transponder receiver
and transmitter functions will be suppressed.
The EXTERNAL SUPPRESSION output is driven to > 18 VDC when the GTX 3X5 transmits. An input voltage of > 10 VDC
will suppress the GTX 3X5.
Table 5-13 External Suppression Bus Pin
5.9
OAT Input
The GTX 3X5 includes an OAT input, used for OAT and density altitude displays.
TEMP PROBE IN uses a current sensor type probe, such as the EDMO P/N 655-PROBE or the Davtron
P/N C307PS. The temperature input specification is 1 microamp per degree Kelvin (1uA/°K). Connect the probe positive
wire to pin 25 and negative wire to pin 3. For wire designations refer to the manufacturer’s specifications.
Table 5-14 OAT Input and Output
5.10 Audio Output
The audio output is used to provide aural traffic alerts. The output is capable of 100 mW into a 500 ohm load.
Table 5-15 Audio Inputs and Outputs
5.11 Time Mark
Table 5-16 Time Mark Outputs
With either a GTX 335 or GTX 345 with internal GPS, the TIME MARK can be used as an output to provide 1PPS to
other equipment in the aircraft.
Pin Name
Connector
Pin
I/O
EXTERNAL SUPPRESSION
P3251
18
I/O
Pin Name
Connector
Pin
I/O
TEMP PROBE OUT
P3251
25
O
TEMP PROBE IN
P3251
3
I
Pin Name
Connector
Pin
I/O
AUDIO OUT HI
P3251
46
O
AUDIO OUT LO
P3251
47
O
Pin Name
Connector
Pin
I/O
TIME MARK A
P3251
4
O
TIME MARK B
P3251
26
O
